The effects of computer-simulated experiments on high school biology students' problem-solving skills and achievement

NASA Astrophysics Data System (ADS)

Carmack, Gay Lynn Dickinson

2000-10-01

This two-part quasi-experimental repeated measures study examined whether computer simulated experiments have an effect on the problem solving skills of high school biology students in a school-within-a-school magnet program. Specifically, the study identified episodes in a simulation sequence where problem solving skills improved. In the Fall academic semester, experimental group students (n = 30) were exposed to two simulations: CaseIt! and EVOLVE!. Control group students participated in an internet research project and a paper Hardy-Weinberg activity. In the Spring academic semester, experimental group students were exposed to three simulations: Genetics Construction Kit, CaseIt! and EVOLVE! . Spring control group students participated in a Drosophila lab, an internet research project, and Advanced Placement lab 8. Results indicate that the Fall and Spring experimental groups experienced significant gains in scientific problem solving after the second simulation in the sequence. These gains were independent of the simulation sequence or the amount of time spent on the simulations. These gains were significantly greater than control group scores in the Fall. The Spring control group significantly outscored all other study groups on both pretest measures. Even so, the Spring experimental group problem solving performance caught up to the Spring control group performance after the third simulation. There were no significant differences between control and experimental groups on content achievement. Results indicate that CSE is as effective as traditional laboratories in promoting scientific problem solving and that CSE is a useful tool for improving students' scientific problem solving skills. Moreover, retention of problem solving skills is enhanced by utilizing more than one simulation.

Failure to produce taste-aversion learning in rats exposed to static electric fields and air ions.

PubMed

Creim, J A; Lovely, R H; Weigel, R J; Forsythe, W C; Anderson, L E

1995-01-01

Taste-aversion (TA) learning was measured to determine whether exposure to high-voltage direct current (HVdc) static electric fields can produce TA learning in male Long Evans rats. Fifty-six rats were randomly distributed into four groups of 14 rats each. All rats were placed on a 20 min/day drinking schedule for 12 consecutive days prior to receiving five conditioning trials. During the conditioning trials, access to 0.1% sodium saccharin-flavored water was given for 20 min, followed 30 min later by one of four treatments. Two groups of 14 rats each were individually exposed to static electric fields and air ions, one group to +75 kV/m (+2 x 10(5) air ions/cm3) and the other group to -75 kV/m (-2 x 10(5) air ions/cm3). Two other groups of 14 rats each served as sham-exposed controls, with the following variation in one of the sham-exposed groups: This group was subdivided into two subsets of seven rats each, so that a positive control group could be included to validate the experimental design. The positive control group (n = 7) was injected with cyclophosphamide 25 mg/kg, i.p., 30 min after access to saccharin-flavored water on conditioning days, whereas the other subset of seven rats was similarly injected with an equivalent volume of saline. Access to saccharin-flavored water on conditioning days was followed by the treatments described above and was alternated daily with water "recovery" sessions in which the rats received access to water for 20 min in the home cage without further treatment. Following the last water-recovery session, a 20 min, two-bottle preference test (between water and saccharin-flavored water) was administered to each group. The positive control group did show TA learning, thus validating the experimental protocol. No saccharin-flavored water was consumed in the two-bottle preference test by the cyclophosphamide-injected, sham-exposed group compared to 74% consumed by the saline-injected sham-exposed controls (P < .0001). Saccharin-preference data for the static field-exposed groups showed no TA learning compared to data for sham-exposed controls. In summary, exposure to intense static electric fields and air ions did not produce TA learning as assessed by this particular design.

Embryo recovery from mares exposed to a year-to-year artificially prolonged daylength.

PubMed

Kot, K; Tischner, M

1991-09-01

The aim of the experiment was to determine the effect of a year-to-year prolonged daylength on the patterns of equine reproductive activity and results of embryo recovery. Experiments using Konik Polski mares were conducted over four reproduction seasons. Five mares were exposed to a regimen of artificially prolonged daylength (APD) and another five mares in a control group were kept under conditions of natural daylight. Both the control and experimental groups were examined for appearance of estrus, ovulation and also for the state of their coats. A single stallion was used for breeding all of the mares. The embryos were recovered nonsurgically 6 to 9 days after ovulation. All of the mares exposed to APD showed increased ovarian activity, which commenced earlier than in the control group. About 19% more ovulations were detected in the experimental group. The average number of ovulations per lighted mare per year was 15.3, while in the control group it was 12.4 ovulations (P<0.05). However, the embryo recovery rate and total number of embryos obtained from the mares exposed to APD did not exceed the number of embryos collected from the control mares (P<0.05). Modification of daylength had a visible effect on the mares by producing a change in their coats.

The effect of extremely low frequency pulsed electromagnetic field on in vitro fertilization success rate in N MRI mice.

PubMed

Hafizi, Leili; Sazgarnia, Ameneh; Mousavifar, Nezhat; Karimi, Mohammad; Ghorbani, Saleh; Kazemi, Mohammad Reza; Emami Meibodi, Neda; Hosseini, Golkoo; Mostafavi Toroghi, Hesam

2014-01-01

The effects of exposure to electromagnetic fields (EMF) on reproduction systems have been widely debated. In this study, we aimed to investigate whether low frequency EMF could ameliorate the in vitro fertilization success rate in Naval medical research institute (NMRI) Mice. In this randomized comparative animal study, ten NMRI mice were randomly divided into 2 equal groups (control and experimental). 10 IU of human chorionic gonadotropin (hCG) was injected intraperitoneally to both groups in order to stimulate ovulating, and ovums were then aspirated and kept in KSOM (modified version of sequential simplex optimization medium with a higher K(+) concentration) culture medium. Metaphase II ovums were separated, and sperms obtained by "swim out" method were added to metaphase II ovums in the culture medium. The experimental group was exposed to 1.3 millitesla pulsed electromagnetic field at 4 kilohertz frequency for 5 hours. To assess the efficacy, we considered the identification of two-pronuclear zygote (2PN) under microscope as fertilizing criterion. Total number of collected ovums in the control and experimental groups was 191 and 173, respectively, from which 58 (30.05%) and 52 (30.36%) ovums were collected from metaphase II, respectively. In vitro fertilization (IVF) success rate was 77% in extremely low frequency- pulsed electromagnetic field (ELFPEMF) for exposed group (experimental), whereas the rate was 68% for control group. Despite increased percentile of IVF success rate in exposed group, there was no statistically significant difference between 2 groups, but this hypothesis has still been stated as a question. Further studies with larger sample sizes and different EMF designs are suggested.

Race, Exposure, and Initial Affective Ratings in Interpersonal Attraction.

ERIC Educational Resources Information Center

Nikels, Kenneth W.; Hamm, Norman H.

To test the mere exposure hypothesis, subjects were exposed to 20 slides of black and white stimulus persons. Based upon pre-experimental ratings, each slide had been initially assigned to one of four groups: high favorable black, high favorable white, low favorable black, and low favorable white. The experimental group, consisting of 25 white…

The developmental effects of extremely low frequency electric fields on visual and somatosensory evoked potentials in adult rats.

PubMed

Gok, Deniz Kantar; Akpinar, Deniz; Hidisoglu, Enis; Ozen, Sukru; Agar, Aysel; Yargicoglu, Piraye

2016-01-01

The purpose of our study was to investigate the developmental effects of extremely low frequency electric fields (ELF-EFs) on visual evoked potentials (VEPs) and somatosensory-evoked potentials (SEPs) and to examine the relationship between lipid peroxidation and changes of these potentials. In this context, thiobarbituric acid reactive substances (TBARS) levels were determined as an indicator of lipid peroxidation. Wistar albino female rats were divided into four groups; Control (C), gestational (prenatal) exposure (Pr), gestational+ postnatal exposure (PP) and postnatal exposure (Po) groups. Pregnant rats of Pr and PP groups were exposed to 50 Hz electric field (EF) (12 kV/m; 1 h/day), while those of C and Po groups were placed in an inactive system during pregnancy. Following parturition, rats of PP and Po groups were exposed to ELF-EFs whereas rats of C and Pr groups were kept under the same experimental conditions without being exposed to any EF during 68 days. On postnatal day 90, rats were prepared for VEP and SEP recordings. The latencies of VEP components in all experimental groups were significantly prolonged versus C group. For SEPs, all components of PP group, P2, N2 components of Pr group and P1, P2, N2 components of Po group were delayed versus C group. As brain TBARS levels were significantly increased in Pr and Po groups, retina TBARS levels were significantly elevated in all experimental groups versus C group. In conclusion, alterations seen in evoked potentials, at least partly, could be explained by lipid peroxidation in the retina and brain.

Atrial and ventricular septal changes in ethanol vapour exposed chick embryos.

PubMed

Kamran, Kiran; Khan, Muhammad Yunus; Minhas, Liaqat Ali

2015-03-01

To study the effects of ethanol vapour exposure on development of atrial and ventricular septa of chick embryo. The experimental study was conducted at the College of Physicians and Surgeons, Islamabad, from 2006 to 2007. The experimental and control groups were further divided into three subgroups based on the day of sacrifice. The experimental group was exposed to ethanol vapours produced in a specially-designed vapour chamber and then compared with age-matched controls. There were 90 eggs in each of the two groups. The development of inter-ventricular septum completed at day 7 of development in chick embryo. Ethanol vapour exposure produced a small discontinuity at day 10 of development in a chick embryo which may be labelled as ventricular septal defect since ventricular development is completed by day 7. Interatrial septum formed till day 7 with small perforations which persisted till hatching. Ethanol vapour exposure may lead to ventricular septal defect.

Evaluating a Problem-Based Learning Strategy for Enhancing Ethical Awareness in Negotiation

DTIC Science & Technology

2011-01-01

experimental (training) or a control (no training) group . The experimental group was exposed to four negotiation scenarios at one-month intervals, and...obtained from the control group . Also, post exercise ethical awareness scores correlated significantly with Cadets’ negotiation strategies. The...completed a modified version of the Ethical Perceptions Scale (EPS) to provide a baseline ( pretest ) measure of their preferences for emphasizing

Hepatic damage in newborns from female rats exposed to the pesticide derivative ethylenethiourea.

PubMed

Lemos, Patrícia Veruska Ribeiro Barbosa; Martins, José Luiz; Lemos, Sidney Pereira Pinto; Santos, Fernando Leandro dos; Silva, Sílvio Romero Gonçalves e

2012-12-01

To evaluate hepatic morphological-histological abnormalities in newborns from female rats exposed to ethylenethiourea. A randomized study was conducted on fifty-five newborn Wistar rats were studied: 34 in the experimental group, whose mothers had been exposed to 1% ethylenethiourea; and 21 in the control group, whose mothers had received 0.9% physiological solution. The solution was administered via gavage on the 11(th) day of gestation. Cesarean section was performed on the 20(th) day of gestation. The newborns' livers were examined and any morphological-histological abnormalities were registered. The presence of megakaryocytes was quantified in 50 microscope fields, as the total number of these cells per mm(2). The entire experimental group presented abnormalities of embryonic formation, with musculoskeletal anomalies, digestive system anomalies, hepatic congestion and friability, hydrops and delayed intrauterine growth. The histopathological analysis showed that morphological-histological hepatic destructuring had occurred in all entire experimental with removal of the hepatic trabeculae and severe hepatic megakaryocytosis. The mean megakaryocyte density ranged from 107.9 to 114.2 per mm(2), and it was eight times greater than in the control group, thus characterizing a situation of extramedullary hematopoiesis. The fetal exposure to ethylenethiourea caused hepatic damage characterized by severe extramedullary hematopoiesis.

Persuader Sex Differences and Peer Pressure Effects on Attitudes Toward Drug Abuse.

ERIC Educational Resources Information Center

Stone, Christopher I.; Shute, Robert E.

This experiment was performed to assess the effects of the experimental confederates' sex and contrived group peer pressure on the drug attitudes of male college students. Subjects were exposed to all male or all female groups of experimental confederates (persuaders) who expressed either extremely pro-drug or anti-drug sentiments in a guided…

Effect of electromagnetic waves from mobile phone on immune status of male rats: possible protective role of vitamin D.

PubMed

El-Gohary, Ola Ahmed; Said, Mona Abdel-Azeem

2017-02-01

There are considerable public concerns about the relationship between mobile phone radiation and human health. The present study assesses the effect of electromagnetic field (EMF) emitted from a mobile phone on the immune system in rats and the possible protective role of vitamin D. Rats were randomly divided into six groups: Group I: control group; Group II: received vitamin D (1000 IU/kg/day) orally; Group III: exposed to EMF 1 h/day; Group IV: exposed to EMF 2 h/day; Group V: exposed to EMF 1 h/day and received vitamin D (1000 IU/kg/day); Group VI: exposed to EMF 2 h/day and received vitamin D (1000 IU/kg/day). After 30 days of exposure time, 1 h/day EMF exposure resulted in significant decrease in immunoglobulin levels (IgA, IgE, IgM, and IgG); total leukocyte, lymphocyte, eosinophil and basophil counts; and a significant increase in neutrophil and monocyte counts. These changes were more increased in the group exposed to 2 h/day EMF. Vitamin D supplementation in EMF-exposed rats reversed these results when compared with EMF-exposed groups. In contrast, 7, 14, and 21 days of EMF exposure produced nonsignificant differences in these parameters among all experimental groups. We concluded that exposure to mobile phone radiation compromises the immune system of rats, and vitamin D appears to have a protective effect.

Effects of laser irradiation on immature olfactory neuroepithelial explants from the rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mester, A.F.; Snow, J.B. Jr.

1988-07-01

The photobiological effect of low-output laser irradiation on the maturation and regeneration of immature olfactory bipolar receptor cells of the rat was studied. The maturation and regeneration of the receptor cells of rat fetuses were quantified in neuroepithelial explants with morphometric analysis. The number of explants with outgrowth and the number and length of neuritic outgrowths were determined on a regular basis for 12 days. Explants in the experimental group were irradiated with a helium-neon laser using different incident energy densities (IED). Explants in the fluorescent light control group were exposed to fluorescent light for the same periods of timemore » as those in the experimental group were exposed to laser irradiation. Explants in another control group were not exposed to laser or fluorescent light irradiation. The IED of 0.5 J/cm2 laser irradiation has been found to increase significantly the number of explants with outgrowth and the number and length of the outgrowths. Other laser IEDs or fluorescent light irradiation did not influence maturation or regeneration.« less

The influence of ethnic concordance and discordance on verbal reports and nonverbal behaviours of pain.

PubMed

Hsieh, Annie Y; Tripp, Dean A; Ji, Li-Jun

2011-09-01

This study's aim was to examine the influence of ethnic concordance on Chinese participants' pain report and nonverbal pain expression in a laboratory setting. Participants (n=102) were exposed to a cold pressor task under 1 of 2 conditions: Chinese milieu (n=52; participants exposed to Chinese experimenters and language), or European Canadian milieu (n=50; participants exposed to Euro-Canadian experimenters and English language). A reference group with 86 Euro-Canadian participants, exposed to the Euro-Canadian milieu only, was included for comparison. The Chinese groups did not differ on pain intensity during the pain task. However, Chinese participants in the Chinese milieu reported significantly higher affective pain and displayed more nonverbal behaviour of pain than the Chinese participants in the Euro-Canadian milieu. In addition, compared to the Euro-Canadian group, both Chinese groups reported higher pain intensity during the pain task and greater affective pain after immersion. The results demonstrated that an ethnically concordant milieu is associated with increased nonverbal pain displays and affective pain report. These findings suggest that research on ethnic disparities in pain treatment should examine ethnic concordance between observer and individual in pain. Copyright © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Effects on Aesthetic Sensitivity of Developing Perception of Musical Expressiveness

ERIC Educational Resources Information Center

Standifer, James A.

1970-01-01

An experimental group and control group were exposed to an innovative program of music education. The former group was composed of lower class children and the latter of middle class children. The greater success was achieved in working with the first group. (CK)

Micronucleated erythrocytes in newborns of rat dams exposed to ultraviolet-A light during pregnancy; protection by ascorbic acid supplementation.

PubMed

Zúñiga-González, Guillermo M; Gómez-Meda, Belinda C; Zamora-Perez, Ana L; Martínez-González, María A; Muñoz de Haro, Ilse A; Pérez-Navarro, Adhoksaja E; Armendáriz-Borunda, Juan; Gallegos-Arreola, Martha P

2015-04-01

Pregnant hairless rat dams were exposed to ultraviolet-A light (UVA) to induce micronucleated erythrocytes (MNE) in their fetuses. The control group was exposed to conventional light; the experimental groups were exposed to UVA (365nm) during gestational days 16-21. In some cases, ascorbic acid (Asc) was administered in the drinking water from gestational day 15 until delivery. Dams were sampled at 48-h intervals during gestation, from day 16 until delivery. Blood was also obtained from neonates at birth; MNE, micronucleated polychromatic erythrocytes (MNPCE), and polychromatic erythrocytes (PCE) were scored. Increased MNE and MNPCE were observed in neonates born to mothers exposed to UVA for 40, 80 or 160min, compared to the control group. Asc treatment reduced MNE and MNPCE induction. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of Smoke Generated by Electrocautery on the Larynx.

PubMed

Atar, Yavuz; Salturk, Ziya; Kumral, Tolgar Lutfi; Uyar, Yavuz; Cakir, Caglar; Sunnetci, Gurcan; Berkiten, Guler

2017-05-01

The aim of this study was to investigate effects of smoke produced by electrocautery on the laryngeal mucosa. We used 16 healthy, adult female Wistar albino rats. We divided the rats into two groups. Eight rats were exposed to smoke for 60 min/d for 4 weeks, and eight rats were not exposed to smoke and served as controls. The experimental group was maintained in a plexiglass cabin during exposure to smoke. At the end of 4 weeks, rats were sacrificed under high-dose ketamine anesthesia. Each vocal fold was removed. An expert pathologist blinded to the experimental group evaluated the tissues for the following: epithelial distribution, inflammation, hyperplasia, and metaplasia. Mucosal cellular activities were assessed by immunohistochemical staining for Ki67. Results taken before and after effect were compared statistically. There was a significant difference in the extent of inflammation between the experimental group and the control group. Squamous metaplasia was detected in each group, but the difference was not significant. None of the larynges in either group developed hyperplasia. We showed increased tissue inflammation due to irritation by the smoke. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Optimizing laboratory animal stress paradigms: The H-H* experimental design.

PubMed

McCarty, Richard

2017-01-01

Major advances in behavioral neuroscience have been facilitated by the development of consistent and highly reproducible experimental paradigms that have been widely adopted. In contrast, many different experimental approaches have been employed to expose laboratory mice and rats to acute versus chronic intermittent stress. An argument is advanced in this review that more consistent approaches to the design of chronic intermittent stress experiments would provide greater reproducibility of results across laboratories and greater reliability relating to various neural, endocrine, immune, genetic, and behavioral adaptations. As an example, the H-H* experimental design incorporates control, homotypic (H), and heterotypic (H*) groups and allows for comparisons across groups, where each animal is exposed to the same stressor, but that stressor has vastly different biological and behavioral effects depending upon each animal's prior stress history. Implementation of the H-H* experimental paradigm makes possible a delineation of transcriptional changes and neural, endocrine, and immune pathways that are activated in precisely defined stressor contexts. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acute effects of cigarette smoke exposure on experimental skin flaps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nolan, J.; Jenkins, R.A.; Kurihara, K.

1985-04-01

Random vascular patterned caudally based McFarlane-type skin flaps were elevated in groups of Fischer 344 rats. Groups of rats were then acutely exposed on an intermittent basis to smoke generated from well-characterized research filter cigarettes. Previously developed smoke inhalation exposure protocols were employed using a Maddox-ORNL inhalation exposure system. Rats that continued smoke exposure following surgery showed a significantly greater mean percent area of flap necrosis compared with sham-exposed groups or control groups not exposed. The possible pathogenesis of this observation as well as considerations and correlations with chronic human smokers are discussed. Increased risks of flap necrosis by smokingmore » in the perioperative period are suggested by this study.« less

Verbal learning in the context of background music: no influence of vocals and instrumentals on verbal learning

PubMed Central

2014-01-01

Background Whether listening to background music enhances verbal learning performance is still a matter of dispute. In this study we investigated the influence of vocal and instrumental background music on verbal learning. Methods 226 subjects were randomly assigned to one of five groups (one control group and 4 experimental groups). All participants were exposed to a verbal learning task. One group served as control group while the 4 further groups served as experimental groups. The control group learned without background music while the 4 experimental groups were exposed to vocal or instrumental musical pieces during learning with different subjective intensity and valence. Thus, we employed 4 music listening conditions (vocal music with high intensity: VOC_HIGH, vocal music with low intensity: VOC_LOW, instrumental music with high intensity: INST_HIGH, instrumental music with low intensity: INST_LOW) and one control condition (CONT) during which the subjects learned the word lists. Since it turned out that the high and low intensity groups did not differ in terms of the rated intensity during the main experiment these groups were lumped together. Thus, we worked with 3 groups: one control group and two groups, which were exposed to background music (vocal and instrumental) during verbal learning. As dependent variable, the number of learned words was used. Here we measured immediate recall during five learning sessions (recall 1 – recall 5) and delayed recall for 15 minutes (recall 6) and 14 days (recall 7) after the last learning session. Results Verbal learning improved during the first 5 recall sessions without any strong difference between the control and experimental groups. Also the delayed recalls were similar for the three groups. There was only a trend for attenuated verbal learning for the group passively listened to vocals. This learning attenuation diminished during the following learning sessions. Conclusions The exposure to vocal or instrumental background music during encoding did not influence verbal learning. We suggest that the participants are easily able to cope with this background stimulation by ignoring this information channel in order to focus on the verbal learning task. PMID:24670048

Dental extraction following zoledronate, induces osteonecrosis in rat's jaw.

PubMed

Vidal-Gutiérrez, X; Gómez-Clavel, J-F; Gaitán-Cepeda, L-A

2017-03-01

Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) is clinically characterized by the presence of exposed bone in the oral cavity that persists for more than eight weeks. Previous attempts to establish an animal model have not sufficiently considered disease features. Our aim was to establish an inexpensive and replicable animal model that develops BRONJ in a short time. Thirty-two male Wistar rats were randomly divided into two groups: control and experimental. In the experimental group, we administered 0.06mg/kg intraperitoneal dose of zoledronic acid (ZA) 7 and 14 days prior to maxillary second molar extraction. At two, four and six weeks after tooth extraction, the animals were euthanized, and we dissected the maxilla following histological procedures. We stained serial slides with hematoxylin and eosin and Masson's trichrome. The samples were harvested for macroscopic, radiologic and histological evaluation of bone changes. At two weeks postextraction, we observed exposed necrotic bone in dental socket areas in experimental groups. Radiological analysis revealed osteolytic lesions accompanied by extensive destruction and sequestrum formation in the same group. Histological examination confirmed the absence of necrotic bone in control groups in contrast with the experimental groups. The percentage of empty lacunae and the number of osteoclasts and the necrotic bone area were significantly increased (p<0.05) in the experimental groups. The animal model using ZA administration to prior dental extraction successfully mimicked human BRONJ lesions. Also, the model was easily replicated, inexpensive and showed different features than other previous BRONJ models.

The effects of music genre on young people's alcohol consumption: an experimental observational study.

PubMed

Engels, Rutger C M E; Poelen, Evelien A P; Spijkerman, Renske; Ter Bogt, Tom

2012-01-01

The aim of this study was to test whether exposure to specific music genres in a social drinking setting leads to differences in drinking levels. An observational experimental design was used in which we invited peer groups of young adults into a bar lab, a lab which is furnished like an ordinary, small pub. Between two tasks, people had a break of 50 minutes in which they could order nonalcoholic and alcoholic beverages. During the break, participants were exposed to a specific music genre: popular, hard rock, rap, or classical music. Those groups who were exposed to classical music drank significantly more alcohol than those who were exposed to other music genres. This pattern is quite robust and does not depend on participants' sex or age, drinking habits, own music preference, and relative importance of music in participant's lives. The study's limitations are mentioned.

Effects of Virtual Reality on the Cognitive Memory and Handgun Accuracy Development of Law Enforcement Neophytes

ERIC Educational Resources Information Center

Wright, Richard A.

2013-01-01

The purpose of this research was to investigate the effects of virtual reality training on the development of cognitive memory and handgun accuracy by law enforcement neophytes. One hundred and six academy students from 6 different academy classes were divided into two groups, experimental and control. The experimental group was exposed to virtual…

PBL-GIS in Secondary Geography Education: Does It Result in Higher-Order Learning Outcomes?

ERIC Educational Resources Information Center

Liu, Yan; Bui, Elisabeth N.; Chang, Chew-Hung; Lossman, Hans G.

2010-01-01

This article presents research on evaluating problem-based learning using GIS technology in a Singapore secondary school. A quasi-experimental research design was carried to test the PBL pedagogy (PBL-GIS) with an experimental group of students and compare their learning outcomes with a control group who were exposed to PBL but not GIS. The…

Embryo developmental capacity of oocytes fertilised by sperm of mouse exposed to forced swimming stress.

PubMed

Ghasem, Saki; Majid, Jasemi; Shiva, Razi

2013-07-01

To assess developmental capacity of fertilised oocytes by sperm of mouse exposed to forced swimming stress. The experimental study was conducted at the Physiology Research Center of Ahvaz Jundishapur University of Medical Sciences, from August 2011 to January 2012. It comprised 20 adult male and 10 female mice. The male mice were randomly divided into two equal groups (n=10): control and experimental. Animals of the experimental group were submitted to forced swimming stress. All male mice were euthanised and the cauda epididymis removed before contents were squeezed out. A pre-incubated capacitated sperm was gently added to the freshly collected ova of the two groups of study. The combined sperm-oocyte suspension was incubated for 4-6 hours under a condition of 5% Carbon dioxide and 37 degreeC temperature. The ova were then washed through several changes of medium and finally incubated. Fertilisation was assessed by recording the number of 1-cell embryos 4-6 hours after insemination. The 1-cell embryos were allowed to further develop in vitro for about 120 hours. Development of embryos everyday and during 5 days of culture was observed by using inverted microscope. SPSS 13.0.1 was used for statistical analysis. The percentage of oocytes fertilised was 75:96 (78.12+/-4.8%) and 50:10 (49.5+/-3.9%) in the control and experimental groups, respectively. The difference was significant (p <0.001). At 24 hours after insemination, 70:75 (93.33+/-2.7%) and 39:50 (78+/-3.5%)of fertilized oocytes developed to two=cell embryos in control and experimental groups respectively.The difference was significant (p <0.02).There were not significant differences (p>0.05) between the two groups in terms of speed and developmental capacity of blastocysts. Fertilisation capacity of male mice affected by forced swimming stress and also the developmental capacity of oocyte fertilised by sperm of mouse exposed to forced swimming stress decreased.

Histological evaluation of direct pulp capping of rat pulp with experimentally developed low-viscosity adhesives containing reparative dentin-promoting agents.

PubMed

Suzuki, Masaya; Taira, Yoshihisa; Kato, Chikage; Shinkai, Koichi; Katoh, Yoshiroh

2016-01-01

This study examines the wound healing process in exposed rat pulp when capped with experimental adhesive resin systems. Experimental adhesive resin system for direct pulp capping was composed of primer-I (PI), -II (PII), and -III (PIII) and an experimental bonding agent (EBA). PI was Clearfil(®) SE Bond(®)/Primer (CSP) containing 5.0 wt% CaCl2, PII was PI containing 10 wt% nanofiller (Aerosil(®) 380), and PIII was CSP containing 5.0 wt% of compounds of equal moles of synthetic peptides (pA and pB) derived from dentin matrix protein 1. EBA was Clearfil(®) SE Bond(®)/Bond (CSB) containing 10 wt% hydroxyapatite powders. Three experimental groups were designed. PI was assigned to experimental Groups 1 and 3. PII was assigned to experimental Groups 2 and 3. PIII and EBA were assigned to all experimental adhesive groups. Control teeth were capped with calcium hydroxide preparation (Dycal(®)), and CSP and CSB were applied to the cavity. The rats were sacrificed after each observation period (14, 28, 56, and 112 days). The following parameters were evaluated: pulp tissue disorganization, inflammatory cell infiltration, reparative dentin formation (RDF), and bacterial penetration. There were no significant differences among all the groups for all parameters and all observation periods (p>0.05, Kruskal-Wallis test). All groups showed initial RDF at 14 days postoperatively and extensive RDF until 112 days postoperatively. Groups 2 and 3 demonstrated higher quantity of mineralized dentin bridge formation compared with Group 1. Addition of nanofillers to the primer was effective in promoting high-density RDF. Experimentally developed adhesive resin systems induce the exposed pulp to produce almost the same quantity of reparative dentin as calcium hydroxide. However, we need further studies to elucidate whether the same results could be obtained in humans. Copyright © 2015 Elsevier Ltd. All rights reserved.

Analysis of emotionality and locomotion in radio-frequency electromagnetic radiation exposed rats.

PubMed

Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Paval, Jaijesh; Kedage, Vivekananda; Bhat, M Shankaranarayana; Nayak, Satheesha; Bhat, P Gopalakrishna

2013-07-01

In the current study the modulatory role of mobile phone radio-frequency electromagnetic radiation (RF-EMR) on emotionality and locomotion was evaluated in adolescent rats. Male albino Wistar rats (6-8 weeks old) were randomly assigned into the following groups having 12 animals in each group. Group I (Control): they remained in the home cage throughout the experimental period. Group II (Sham exposed): they were exposed to mobile phone in switch-off mode for 28 days, and Group III (RF-EMR exposed): they were exposed to RF-EMR (900 MHz) from an active GSM (Global system for mobile communications) mobile phone with a peak power density of 146.60 μW/cm(2) for 28 days. On 29th day, the animals were tested for emotionality and locomotion. Elevated plus maze (EPM) test revealed that, percentage of entries into the open arm, percentage of time spent on the open arm and distance travelled on the open arm were significantly reduced in the RF-EMR exposed rats. Rearing frequency and grooming frequency were also decreased in the RF-EMR exposed rats. Defecation boli count during the EPM test was more with the RF-EMR group. No statistically significant difference was found in total distance travelled, total arm entries, percentage of closed arm entries and parallelism index in the RF-EMR exposed rats compared to controls. Results indicate that mobile phone radiation could affect the emotionality of rats without affecting the general locomotion.

The Effect of 5E-Learning Model Supported with Webquest Media on Students' Achievement and Satisfaction

ERIC Educational Resources Information Center

Sahin, Semsettin M. S.; Baturay, Meltem Huri

2016-01-01

The purpose of this research study is to investigate the effect of the 5E-learning model supported with WebQuest media on the achievement and satisfaction of students. Therefore, two groups of students were compared in an experimental research design model. The experimental group was exposed to the 5E-learning model supported with WebQuest media;…

Dental extraction following zoledronate, induces osteonecrosis in rat´s jaw

PubMed Central

Gómez-Clavel, José-Francisco; Gaitán-Cepeda, Luis-Alberto

2017-01-01

Background Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) is clinically characterized by the presence of exposed bone in the oral cavity that persists for more than eight weeks. Previous attempts to establish an animal model have not sufficiently considered disease features. Our aim was to establish an inexpensive and replicable animal model that develops BRONJ in a short time. Material and Methods Thirty-two male Wistar rats were randomly divided into two groups: control and experimental. In the experimental group, we administered 0.06mg/kg intraperitoneal dose of zoledronic acid (ZA) 7 and 14 days prior to maxillary second molar extraction. At two, four and six weeks after tooth extraction, the animals were euthanized, and we dissected the maxilla following histological procedures. We stained serial slides with hematoxylin and eosin and Masson’s trichrome. The samples were harvested for macroscopic, radiologic and histological evaluation of bone changes. Results At two weeks postextraction, we observed exposed necrotic bone in dental socket areas in experimental groups. Radiological analysis revealed osteolytic lesions accompanied by extensive destruction and sequestrum formation in the same group. Histological examination confirmed the absence of necrotic bone in control groups in contrast with the experimental groups. The percentage of empty lacunae and the number of osteoclasts and the necrotic bone area were significantly increased (p<0.05) in the experimental groups. Conclusions The animal model using ZA administration to prior dental extraction successfully mimicked human BRONJ lesions. Also, the model was easily replicated, inexpensive and showed different features than other previous BRONJ models. Key words:Bisphosphonates, osteonecrosis, dental extractions, animal model, BRONJ. PMID:28160593

Characterization of material surfaces exposed to atomic oxygen on space shuttle missions

NASA Technical Reports Server (NTRS)

Fromhold, A. T.

1985-01-01

Material samples prepared for exposure to ambient atomic oxygen encountered during space shuttle flights in low Earth orbit were characterized by the experimental techniques of ELLIPSOMETRY, ESCA, PIXE, and RBS. The first group of samples, which were exposed during the STS-8 mission, exhibited some very interesting results. The second group of samples, which are to be exposed during the upcoming STS-17 mission, have been especially prepared to yield quantitative information on the optical changes, oxygen solution, and surface layer formation on metal films of silver, gold, nickel, chromium, aluminum, platinum, and palladium evaporated onto optically polished silicon wafers.

Effects of electromagnetic radiation on the hemorheology of rats

NASA Astrophysics Data System (ADS)

Huang, Zhiwei; Tian, Tian; Xiao, Bo; Li, Wen

2017-01-01

The current work examines the effects of electromagnetic radiation on the hemorheology to provide an experimental basis for radiation protection. Electromagnetic radiation was generated by a Helmholtz coil constructed from copper wire. There were six rats altogether: three rats in the experimental group, and three rats in the control group. The rats in the experimental group were continuously exposed to radiation for 10 hours every day, and rats in the control group remained in a normal environment. After 30 days, the characteristics of hemorheology of the two groups were compared. The average plasma viscosity, whole blood high shear velocity, and whole blood low shear viscosity were lower in rats in the experimental group than in rats in the control group, while the whole blood shear viscosity was higher in the experimental group than in the control group. Results suggest that long term exposure to electromagnetic radiation does have certain impacts on the cardiovascular system, deeming it necessary to take preventative measures.

The Effects of Pre- Versus Post-Presentation Input Flooding via Reading on the Young Iranian EFL Learners' Acquisition of Simple Past Tense

ERIC Educational Resources Information Center

Rikhtegar, Omid; Gholami, Javad

2015-01-01

The purpose of this study was to find out the possible effects of pre-versus post-presentation input flooding via reading on simple past tense acquisition among young Iranian EFL learners. Sixty one elementary EFL learners were divided into two experimental and one control group. The experimental groups were exposed to pre and post presentation…

Glucocorticoid levels after exposure to predator odor and chronic psychosocial stress with dexamethasone application in rats.

PubMed

Starcevic, Ana; Petricevic, Sasa; Radojicic, Zoran; Djulejic, Vuk; Ilankovic, Andrej; Starcevic, Branislav; Filipovic, Branislav

2016-05-01

This study was conducted to explore the effects of specific psychosocial paradigm on predator animal posttraumatic stress model and to test the hypothesis that psychosocially stressed rats would exibit abnormal levels of cortisol and a larger suppression of cortisol levels after the application of dexamethasone. Animals were divided in two groups: experimental and control groups. The experimental group was exposed to two types of stressors: acute immobilization stress, and combined predator stress and daily social stress with application of dexamethasone. Blood sampling was performed at three different times. We found statistically significant results after analyzing the differences between cortisol levels in different times of blood sampling in the group of animals exposed to stress with dexamethasone application. Statistical significance was found when we compared the experimental group with the control group in terms of elevated cortisol levels during blood sampling after stress paradigm exposition. Many significant disruptions in the functioning of the hypothalamic-pituitary-adrenal axis were observed, such as decrease in basal cortisol levels and enhanced dexamethasone-induced inhibition of cortisol levels. These findings are important because their impact can translate to human individuals with posttraumatic stress disorder, which is the most important role of every animal model in research. Copyright © 2016. Published by Elsevier Taiwan.

Effect of grapeseed oil on diazinon-induced physiological and histopathological alterations in rats.

PubMed

Al-Attar, Atef Mohammed

2015-05-01

The pollution of environment by toxic chemicals is a global and chronic problem. Human health risk due to exposure to chemical pollutants is constantly increasing. Pesticides form major toxic chemicals in environment. Scientifically, there is an obviously correlation between the exposure to pesticides and appearance of many diseases. Currently, the significance of natural products for health and medicine has been formidable. The present study investigated the effect of grapeseed oil in male rats exposed to diazinon. The experimental rats were divided into five groups. The rats of the first group were served as control. The experimental animals of the second group were exposed to diazinon (DZN). The animals of the third group were supplemented with grapeseed oil and treated with DZN. The rats of the fourth group were supplemented with grapeseed oil. The experimental rats of the fifth group were supplemented with corn oil. Hematobiochemical and histopathological evaluations were chosen as indicators of DZN toxicity and protective role of grapeseed oil. In rats exposed only to DZN, the levels of serum glucose, triglycerides, cholesterol, low density lipoprotein cholesterol, very low density lipoprotein cholesterol, creatinine, urea nitrogen, uric acid, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, creatine kinase and lactate dehydrogenase were statistically increased, while the level of serum total protein was significantly decreased. Moreover, the histopathological evaluations of the liver, kidney and testis showed that DZN causes several severe alterations. Pretreatment with grapeseed oil exhibited a protective role against DZN toxicity which confirmed by the inhibition of hematobiochemical and histopathological changes due to DZN exposure. Additionally, the present study suggests that the effect of grapeseed oil supplementation against DZN toxicity may be attributed to the antioxidant role of its constituents.

Dietary glutamine prevents the loss of intestinal barrier function and attenuates the increase in core body temperature induced by acute heat exposure.

PubMed

Soares, Anne D N; Costa, Kátia A; Wanner, Samuel P; Santos, Rosana G C; Fernandes, Simone O A; Martins, Flaviano S; Nicoli, Jacques R; Coimbra, Cândido C; Cardoso, Valbert N

2014-11-28

Dietary glutamine (Gln) supplementation improves intestinal function in several stressful conditions. Therefore, in the present study, the effects of dietary Gln supplementation on the core body temperature (T core), bacterial translocation (BT) and intestinal permeability of mice subjected to acute heat stress were evaluated. Male Swiss mice (4 weeks old) were implanted with an abdominal temperature sensor and randomly assigned to one of the following groups fed isoenergetic and isoproteic diets for 7 d before the experimental trials: group fed the standard AIN-93G diet and exposed to a high ambient temperature (39°C) for 2 h (H-NS); group fed the AIN-93G diet supplemented with l-Gln and exposed to a high temperature (H-Gln); group fed the standard AIN-93G diet and not exposed to a high temperature (control, C-NS). Mice were orally administered diethylenetriaminepentaacetic acid radiolabelled with technetium (99mTc) for the assessment of intestinal permeability or 99mTc-Escherichia coli for the assessment of BT. Heat exposure increased T core (approximately 41°C during the experimental trial), intestinal permeability and BT to the blood and liver (3 h after the experimental trial) in mice from the H-NS group relative to those from the C-NS group. Dietary Gln supplementation attenuated hyperthermia and prevented the increases in intestinal permeability and BT induced by heat exposure. No correlations were observed between the improvements in gastrointestinal function and the attenuation of hyperthermia by Gln. Our findings indicate that dietary Gln supplementation preserved the integrity of the intestinal barrier and reduced the severity of hyperthermia during heat exposure. The findings also indicate that these Gln-mediated effects occurred through independent mechanisms.

Histological Effects of Enamel Matrix Derivative on Exposed Dental Pulp.

PubMed

Bajić, Marijana Popović; Danilović, Vesna; Prokić, Branislav; Prokić, Bogomir Bolka; Manojlović, Milica; Živković, Slavoljub

2015-01-01

Direct pulp capping procedure is a therapeutic application of a drug on exposed tooth pulp in order to ensure the closure of the pulp chamber and to allow the healing process to take place. The aim of this study was to examine the histological effects of Emdogain® on exposed tooth pulp of a Vietnamese pig (Sus scrofa verus). The study comprised 20 teeth of a Vietnamese pig. After class V preparation on the buccal surfaces of incisors, canines and first premolars, pulp was exposed. In the experimental group, the perforations were capped with Emdogain® (Straumann, Basel, Switzerland), while in the control group pulp capping was performed with MTA® (Dentsply Tulsa Dental, Johnson City, TN, USA). All cavities were restored with glass-ionomer cement (GC Fuji VIII, GC Corporation, Tokyo, Japan). The observational period was 28 days, after which the animal was sacrificed and histological preparations were made. A light microscope was used to analyze dentin bridge formation, tissue reorganization and inflammation, and the presence of bacteria in the pulp. The formation of dentin bridge was observed in the experimental and control groups. Inflammation of the pulp was mild to moderate in both groups. Angiogenesis and many odontoblast-like cells, responsible for dentin bridge formation, were observed. Necrosis was not observed in any case, nor were bacteria present in the pulp. Histological analysis indicated a favorable therapeutic effect of Emdogain® Gel in direct pulp capping of Vietnamese pigs. Pulp reaction was similar to that of MTA®.

Effects of electromagnetic pulse on bone metabolism of mice in vivo.

PubMed

Li, Kang-Chu; Ma, Shi-Rong; Ding, Gui-Rong; Guo, Yao; Guo, Guo-Zhen

2009-12-01

To study the effects of electromagnetic pulse (EMP) on bone metabolism of mice in vivo. Twenty-four male BALB/c mice were divided into a control group and 2 experimental groups (n=8). The whole-body of mice in experimental groups were exposed to 50 kV/m and 400kV/m EMP, 400 pulses daily for 7 consecutive days at 2 seconds intervals. Alkaline phosphotase (ALP) activity, serum calcium concentration and osteocalcin level and trabecular bone volume (BV/TV, %) were measured immediately after EMP exposure by biochemical, ELISA and morphological methods. The ALP activity, serum calcium concentration and osteocalcin level and BV/TV in experimental groups remained unchanged after EMP exposure. Conclusion Under our experimental conditions, EMP exposure cannot affect bone metabolism of mice in vivo.

Exposure to mobile phone electromagnetic field radiation, ringtone and vibration affects anxiety-like behaviour and oxidative stress biomarkers in albino wistar rats.

PubMed

Shehu, Abubakar; Mohammed, Aliyu; Magaji, Rabiu Abdussalam; Muhammad, Mustapha Shehu

2016-04-01

Research on the effects of Mobile phone radio frequency emissions on biological systems has been focused on noise and vibrations as auditory stressors. This study investigated the potential effects of exposure to mobile phone electromagnetic field radiation, ringtone and vibration on anxiety-like behaviour and oxidative stress biomarkers in albino wistar rats. Twenty five male wistar rats were randomly divided into five groups of 5 animals each: group I: exposed to mobile phone in switched off mode (control), group II: exposed to mobile phone in silent mode, group III: exposed to mobile phone in vibration mode, group IV: exposed to mobile phone in ringtone mode, group V: exposed to mobile phone in vibration and ringtone mode. The animals in group II to V were exposed to 10 min call (30 missed calls for 20 s each) per day for 4 weeks. Neurobehavioural studies for assessing anxiety were carried out 24 h after the last exposure and the animals were sacrificed. Brain samples were collected for biochemical evaluation immediately. Results obtained showed a significant decrease (P < 0.05) in open arm duration in all the experimental groups when compared to the control. A significant decrease (P < 0.05) was also observed in catalase activity in group IV and V when compared to the control. In conclusion, the results of the present study indicates that 4 weeks exposure to electromagnetic radiation, vibration, ringtone or both produced a significant effect on anxiety-like behavior and oxidative stress in young wistar rats.

Flexible attention deployment in threatening contexts: an instructed fear conditioning study.

PubMed

Shechner, Tomer; Pelc, Tatiana; Pine, Daniel S; Fox, Nathan A; Bar-Haim, Yair

2012-10-01

Factors leading humans to shift attention away from danger cues remain poorly understood. Two laboratory experiments reported here show that context interacts with learning experiences to shape attention avoidance of mild danger cues. The first experiment exposed 18 participants to contextual threat of electric shock. Attention allocation to mild danger cues was then assessed with the dot-probe task. Results showed that contextual threat caused subjects to avert attention from danger cues. In the second experiment, 36 participants were conditioned to the same contextual threat used in Experiment 1. These subjects then were randomly assigned to either an experimental group, trained to shift attention toward danger cues, or a placebo group exposed to the same stimuli without the training component. As in Experiment 1, contextual threat again caused attention allocation away from danger in the control group. However, this did not occur in the experimental group. These experiments show that acute contextual threat and learning experiences interact to shape the deployment of attention away from danger cues.

Evaluation of passive avoidance learning and spatial memory in rats exposed to low levels of lead during specific periods of early brain development.

PubMed

Rao Barkur, Rajashekar; Bairy, Laxminarayana K

2015-01-01

Widespread use of heavy metal lead (Pb) for various commercial purposes has resulted in the environmental contamination caused by this metal. The studies have shown a definite relationship between low level lead exposure during early brain development and deficit in children's cognitive functions. This study investigated the passive avoidance learning and spatial learning in male rat pups exposed to lead through their mothers during specific periods of early brain development. Experimental male rats were divided into 5 groups: i) the normal control group (NC) (N = 12) consisted of rat offspring born to mothers who were given normal drinking water throughout gestation and lactation, ii) the pre-gestation lead exposed group (PG) (N = 12) consisted of rat offspring, mothers of these rats had been exposed to 0.2% lead acetate in the drinking water for 1 month before conception, iii) the gestation lead exposed group (G) (N = 12) contained rat offspring born to mothers who had been exposed to 0.2% lead acetate in the drinking water throughout gestation, iv) the lactation lead exposed group (L) (N = 12) had rat offspring, mothers of these rats exposed to 0.2% lead acetate in the drinking water throughout lactation and v) the gestation and lactation lead exposed group (GL) (N = 12) contained rat offspring, mothers of these rats were exposed to 0.2% lead acetate throughout gestation and lactation. The study found deficit in passive avoidance learning in the G, L and GL groups of rats. Impairment in spatial learning was found in the PG, G, L and GL groups of rats. Interestingly, the study found that gestation period only and lactation period only lead exposure was sufficient to cause deficit in learning and memory in rats. The extent of memory impairment in the L group of rats was comparable with the GL group of rats. So it can be said that postnatal period of brain development is more sensitive to neurotoxicity compared to prenatal exposure. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Failure to produce taste-aversion learning in rats exposed to static electric fields and air ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Creim, J.A.; Lovely, R.H.; Weigel, R.J.

1995-12-01

Taste-aversion (TA) learning was measured to determine whether exposure to high-voltage direct current (HVdc) static electric fields can produce TA learning in male Long Evans rats. Fifty-six rats were randomly distributed into four groups of 14 rats each. All rats were placed on a 20 min/day drinking schedule for 12 consecutive days prior to receiving five conditioning trials. During the conditioning trials, access to 0.1% sodium saccharin-flavored water was given for 20 min, followed 30 min later by one of four treatments. Two groups of 14 rats each were individually exposed to static electric fields and air ions, one groupmore » to +75 kV/m (+2 {times} 10{sup 5} air ions/cm{sup 3}) and the other group to {minus}75 kV/m ({minus}2 {times} 10{sup 5} air ions/cm{sup 3}). Two other groups of 14 rats each served as sham-exposed controls, with the following variation in one of the sham-exposed groups: this group was subdivided into two subsets of seven rats each, so that a positive control group could be included to validate the experimental design. The positive control group (n = 7) was injected with cyclophosphamide 25 mg/kg, i.p., 30 min after access to saccharin-flavored water on conditioning days, whereas the other subset of seven rats was similarly injected with an equivalent volume of saline. Access to saccharin-flavored water on conditioning days was followed by the treatments described above and was alternated daily with water recovery sessions in which the rats received access to water for 20 min in the home cage without further treatment. Following the last water-recovery session, a 20 min, two-bottle preference test (between water and saccharin-flavored water) was administered to each group. The positive control group did show TA learning, thus validating the experimental protocol.« less

Effect of simulation on the ability of first year nursing students to learn vital signs.

PubMed

Eyikara, Evrim; Baykara, Zehra Göçmen

2018-01-01

The acquisition of cognitive, affective and psychomotor knowledge and skills are required in nursing, made possible via an interactive teaching method, such as simulation. This study conducted to identify the impact of simulation on first-year nursing students' ability to learn vital signs. A convenience sample of 90 first-year nursing students enrolled at a University, Ankara, in 2014-2015. Ninety students enrolled for lessons on the "Fundamentals of Nursing" were identified using a simple random sampling method. The students were taught vital signs theory via traditional methods. They were grouped into experimental 1, experimental 2 and control group, of 30 students each. Students in the experimental 1 group attended sessions on simulation and those in the experimental 2 group sessions on laboratory work, followed by simulation. The control group were taught via traditional methods and only attended the laboratory work sessions. The students' cognitive knowledge acquisition was evaluated using a knowledge test before and after the lessons. The ability to measure vital signs in adults (healthy ones and patients) was evaluated using a skill control list. A statistically significant difference was not observed between the groups in terms of the average pre-test scores on knowledge (p>0.050). Groups exposed to simulation obtained statistically significantly higher scores than the control group in post-test knowledge (p<0.050). The ability of the groups exposed to simulation to measure vital signs in healthy adults and patients was more successful than that the control group (p<0.050). This was statistically significant. Simulation had a positive effect on the ability of nursing students to measure vital signs. Thus, simulation should be included in the mainstream curriculum in order to effectively impart nursing knowledge and skills. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental assessment of houseflies as vectors in avian influenza subtype H5N1 transmission in chickens.

PubMed

Wanaratana, S; Amonsin, A; Chaisingh, A; Panyim, S; Sasipreeyajan, J; Pakpinyo, S

2013-06-01

In this study, laboratory-reared houseflies were experimentally exposed to the high pathogenicity avian influenza virus (HPAI) subtype H5N1 virus to evaluate the houseflies as vectors in HPAI-H5N1 virus transmission in chickens. One hundred and fifty houseflies (Musca domestica L.) were equally allocated into three groups. Groups 2 and 3 were exposed to the HPAI-H5N1 virus by allowing the flies to consume food containing the virus for 15 min, while the flies in group 1 were allowed to consume H5N1-free food and would serve as a negative control group. Group 2 flies were euthanatized immediately after H5N1 exposure, while group 3 were held at room temperature for 24 hr and euthanatized. The houseflies in the transmission of the HPAI-H5N1 virus were examined by challenging three groups of housefly homogenates into layer chickens via the oral drop. Morbidity and mortality were observed for 14 days, and virus shedding monitored via oropharyngeal swabs (OS) and cloacal swabs (CS), which were collected daily and determined by real-time reverse transcription-PCR and virus titration. Experimental challenge showed that all the chickens of groups 2 and 3 died within 7 days of inoculation. The OS had higher concentrations of virus than CS. Moreover, the chickens of group 2 had higher concentrations of virus shedding than the chickens of group 3. Immunohistochemistry detected the nucleoprotein of the type A influenza virus in all tissue samples collected, including the trachea, duodenum, pancreas, and brain. In summary, this study demonstrates that houseflies could serve as vectors in HPAI-H5N1 virus transmission in chickens under experimental conditions.

Effects of Circadian Disruption on Methamphetamine Consumption in Methamphetamine-Exposed Rats

PubMed Central

Doyle, Susan E.; Feng, Hanting; Garber, Garrett; Menaker, Michael; Lynch, Wendy J.

2015-01-01

Rationale A substantial number of clinical studies indicate associations between sleep abnormalities and drug abuse; however, the role played by the circadian system in the development of addiction is largely unknown. Objective The aim of this study was to examine the effects of experimentally induced chronic jet lag on methamphetamine consumption in a rat model of methamphetamine drinking. Methods Male Sprague-Dawley rats (n=32) were housed in running wheel cages in a 12:12 light:dark cycle. One group of rats (n=16) was given two weeks of forced methamphetamine consumption (0.01% in drinking water; meth pre-exposed) while a second group (n=16, not pre-exposed) received water only. This was followed by a two week abstinence period during which half of the animals from each group were exposed to 4 consecutive 6-hr advancing phase shifts of the light:dark cycle, while the other half remained on the original light:dark cycle. Methamphetamine consumption was assessed in all rats following the deprivation period using a two-bottle choice paradigm. Results Methamphetamine consumption was initially lower in methamphetamine pre-exposed vs. not pre-exposed rats. However, during the second week following abstinence, consumption was significantly higher in phase shifted rats of the methamphetamine pre-exposed group compared to all other groups. Conclusions These data reveal an effect of circadian rhythm disturbance on methamphetamine consumption, and suggest that dysregulation of the circadian system be considered in the etiology of relapse and addiction. PMID:25543849

Effects of circadian disruption on methamphetamine consumption in methamphetamine-exposed rats.

PubMed

Doyle, Susan E; Feng, Hanting; Garber, Garrett; Menaker, Michael; Lynch, Wendy J

2015-06-01

A substantial number of clinical studies indicate associations between sleep abnormalities and drug abuse; however, the role played by the circadian system in the development of addiction is largely unknown. The aim of this study was to examine the effects of experimentally induced chronic jet lag on methamphetamine consumption in a rat model of methamphetamine drinking. Male Sprague-Dawley rats (n = 32) were housed in running wheel cages in a 12:12 h light:dark cycle. One group of rats (n = 16) was given 2 weeks of forced methamphetamine consumption (0.01 % in drinking water; meth pre-exposed) while a second group (n = 16, not pre-exposed) received water only. This was followed by a 2-week abstinence period during which half of the animals from each group were exposed to four consecutive 6-h advancing phase shifts of the light:dark cycle, while the other half remained on the original light:dark cycle. Methamphetamine consumption was assessed in all rats following the deprivation period using a two-bottle choice paradigm. Methamphetamine consumption was initially lower in methamphetamine pre-exposed versus not pre-exposed rats. However, during the second week following abstinence, consumption was significantly higher in phase-shifted rats of the methamphetamine pre-exposed group compared to all other groups. These data reveal an effect of circadian rhythm disturbance on methamphetamine consumption and suggest that dysregulation of the circadian system be considered in the etiology of relapse and addiction.

Impulsive Choice, Alcohol Consumption, and Pre-Exposure to Delayed Rewards: II. Potential Mechanisms

PubMed Central

Stein, Jeffrey S.; Renda, C. Renee; Hinnenkamp, Jay E.; Madden, Gregory J.

2014-01-01

In a prior study (Stein et al., 2013), we reported that rats pre-exposed to delayed rewards made fewer impulsive choices, but consumed more alcohol (12% wt/vol), than rats pre-exposed to immediate rewards. To understand the mechanisms that produced these findings, we again pre-exposed rats to either delayed (17.5 s; n = 32) or immediate (n = 30) rewards. In post-tests, delay-exposed rats made significantly fewer impulsive choices at both 15- and 30-s delays to a larger, later food reward than the immediacy-exposed comparison group. Behavior in an open-field test provided little evidence of differential stress exposure between groups. Further, consumption of either 12% alcohol or isocaloric sucrose in subsequent tests did not differ between groups. Because Stein et al. introduced alcohol concentration gradually (3–12%), we speculate that their group differences in 12% alcohol consumption were not determined by alcohol’s pharmacological effects, but by another variable (e.g., taste) that was preserved as an artifact from lower concentrations. We conclude that pre-exposure to delayed rewards generalizes beyond the pre-exposure delay; however, this same experimental variable does not robustly influence alcohol consumption. PMID:25418607

Using inquiry-based instructional strategies in third-grade science

NASA Astrophysics Data System (ADS)

Harris, Fanicia D.

The purpose of the study was to determine if the use of inquiry-based instructional strategies as compared to traditional instructional strategies would increase third-grade students' achievement in science, based on the pretest/posttest of the school system and the Georgia Criterion-Referenced Competency Test (CRCT). Inquiry-based instruction, presented students with a question, an observation, a data set, or a hypothesis for problem solving such as scientists use when working in real-world situations. This descriptive research employed a quantitative strategy using a pretest/posttest control group design. The research compared the science academic achievement levels of one Grade 3 class [N=14] exposed to a teacher's inquiry-based instructional strategies as compared to one Grade 3 class [ N=18] exposed to a teacher's traditional instructional strategies. The study compared the science academic performance levels of third-grade students as measured by pretest/posttest mean scores from the school system-based assessment and the Georgia CRCT. Four research hypotheses were examined. Based on the overall findings from this study, both the experimental group and the control group significantly increased their mean scores from the pretests to the posttests. The amount of gain from the pretest to the posttest was significantly greater for the experimental group than the control group for pretest/posttest 1 [t(12) = 8.79, p < .01] and pretest/posttest 2 [t(12) = 9.40, p < .01]. The experimental group significantly outperformed the control group with regard to their mean number of items answered correctly on the life sciences test [t(27) = -1.95, p = .06]. Finally, the control group did not outperform the experimental group on any of the comparisons made throughout this study. The results of this study provide empirical support for the effectiveness of the use of inquiry-based learning strategies, given that the experimental group outperformed the control group on all four posttests, on the science CRCT and on the individual Science portions on the test including earth, life and physical sciences. In fact, this study was able to detect significant differences between the experimental group and the control group with regard to the degree to which the students improved from the pretests to the posttests.

Effects of 4% Icodextrin on Experimental Spinal Epidural Fibrosis.

PubMed

Karanci, Turker; Kelten, Bilal; Karaoglan, Alper; Cinar, Nilgun; Midi, Ahmet; Antar, Veysel; Akdemir, Hidayet; Kara, Zeynep

2017-01-01

The aim of this experimental study was to investigate whether spinal epidural 4% glucose polymer solution is effective in the prevention of postoperative fibrosis. Twenty eight adult Wistar albino rats were randomly divided into two equal groups, including treatment and control. Both groups underwent L1 vertebral total laminectomy to expose the dura. Topical treatment group received 4% icodextrin. Four weeks later, epidural fibrosis was examined in both groups histologically, biochemically and macroscopically. Topical use of 4% icodextrin prevented significantly epidural fibrosis following the laminectomy operation. Topical 4% icodextrin application inhibits postoperative epidural fibrosis with various mechanisms and prevents adhesions by playing barrier role between tissue surfaces through flotation. Our study is first to present evidence of experimental epidural fibrosis prevention with 4% icodextrin.

Is Sexual Objectification and Victimization of Females in Video Games Associated With Victim Blaming or Victim Empathy?

PubMed

Beck, Victoria; Rose, Chris

2018-04-01

The goal of this study was to investigate whether the sexual objectification and virtual violence against females in video games increases negative attitudes toward females, when addressing a variety of noted methodological issues. Study participants were randomly assigned to a control group, where participants played Madden NFL 12, or an experimental group, where participants played Grand Theft Auto. In the experimental group, participants played the game with a confederate, who exposed participants to sexual objectification and violence against females. Study results indicated that both the experimental and control groups had equivalently low levels of rape myth acceptance prior to game play. Immediately after game play, there still was no statistically significant difference in rape myth acceptance between groups; however, there was a decrease in rape myth acceptance for the experimental group. The decrease in rape myth acceptance continued and magnified for the experimental group, over time, to the point of creating a statistically significant difference between the two groups for the follow-up measure at the end of the study.

Effects of using human patient simulator versus a CD-ROM on learning the management of patients exposed to chemical agents.

PubMed

Johnson, Don; Flagg, Amanda; Dremsa, Theresa L

2010-01-01

Very little prospective, randomized, experimental research exists on the use of simulation as a teaching method, and no studies have compared the effects of 2 strategies of using the Human Patient Simulator (HPS) and a CD-ROM on the management of patients exposed to chemical agents. A prospective, pretest-posttest experimental, mixed design (within and between) was used to determine if there were statistically significant differences between educational strategies using HPS, CD-ROM, and a control group in the care of patients exposed to chemical agents. Care was operationally defined as the score on the Management of Chemical Warfare Patients Performance (MCWPP) instrument. Participants included active duty and reserve military nurses (n=92). They were randomly assigned to one of 3 teaching groups: HPS (n=30), CD-ROM (n=31), or a control group (n=31). Analysis of variance and a Tukey post-hoc test were used to analyze the data. The means on MCWPP instrument were as follows: HPS (pretest: mean=65.13, SD ± 8.9; posttest mean=73.0, SD ± 8.6); CD-ROM (pretest: mean=67.74, SD ± 11.18, posttest mean=65.67, SD ± 10.82); control (pretest: mean=68.51 SD ± 8.5; posttest mean=62.6, SD ± 8.6). There were no significant differences between the groups on the pretest (P=.363), but there were significant differences on the posttest (P=.001). Post-hoc analyses indicated the HPS group performed better than the CD-ROM group (P=.017) and the control group (P=.000). There was no significant difference between the CD-ROM and control groups (P=.485). Based on the results of this study, the HPS is more effective than the CD-ROM in teaching nurses about the care of patients exposed to chemical agents.

Microteaching and Pre-Service Teachers' Sense of Self-Efficacy in Teaching

ERIC Educational Resources Information Center

Arsal, Zeki

2014-01-01

This study examined the effect of microteaching on pre-service teachers' sense of self-efficacy in teaching using a pre-test/post-test quasi-experimental design. The sample of the study consisted of 70 pre-service teachers on a special education teacher preparation programme. The pre-service teachers in the experimental group were exposed to…

Effect of Radiofrequency Radiation Emitted from 2G and 3G Cell Phone on Developing Liver of Chick Embryo – A Comparative Study

PubMed Central

Swer, Rijied Thompson; Anbalagan, J.; Rajesh, Bhargavan

2017-01-01

Introduction The increasing scientific evidence of various health hazards on exposure of Radiofrequency Radiation (RFR) emitted from both the cell phones and base stations have caused significant media attention and public discussion in recent years. The mechanism of interaction of RF fields with developing tissues of children and fetuses may be different from that of adults due to their smaller physical size and variation in tissue electromagnetic properties. The present study may provide an insight into the basic mechanisms by which RF fields interact with developing tissues in an embryo. Aim To evaluate the possible tissue and DNA damage in developing liver of chick embryo following chronic exposure to Ultra-High Frequency/Radiofrequency Radiation (UHF/RFR) emitted from 2G and 3G cell phone. Materials and Methods Fertilized chick embryos were incubated in four groups. Group A-experimental group exposed to 2G radiation (60 eggs), Group B- experimental group exposed to 3G radiation (60 eggs), Group C- sham exposed control group (60 eggs) and Group D– control group (48 eggs). On completion of scheduled duration, the embryos were collected and processed for routine histological studies to check structural changes in liver. The nuclear diameter and karyorrhexis changes of hepatocytes were analysed using oculometer and square reticule respectively. The liver procured from one batch of eggs from all the four groups was subjected to alkaline comet assay technique to assess DNA damage. The results were compared using one-way ANOVA test. Results In our study, the exposure of developing chick embryos to 2G and 3G cell phone radiations caused structural changes in liver in the form of dilated sinusoidal spaces with haemorrhage, increased vacuolations in cytoplasm, increased nuclear diameter and karyorrhexis and significantly increased DNA damage. Conclusion The chronic exposure of chick embryo liver to RFR emitted from 2G and 3G cell phone resulted in various structural changes and DNA damage. The changes were more pronounced in 3G experimental group. Based on these findings it is necessary to create awareness among public about the possible ill effects of RFR exposure from cell phone. PMID:28892876

Effect of Radiofrequency Radiation Emitted from 2G and 3G Cell Phone on Developing Liver of Chick Embryo - A Comparative Study.

PubMed

D'Silva, Mary Hydrina; Swer, Rijied Thompson; Anbalagan, J; Rajesh, Bhargavan

2017-07-01

The increasing scientific evidence of various health hazards on exposure of Radiofrequency Radiation (RFR) emitted from both the cell phones and base stations have caused significant media attention and public discussion in recent years. The mechanism of interaction of RF fields with developing tissues of children and fetuses may be different from that of adults due to their smaller physical size and variation in tissue electromagnetic properties. The present study may provide an insight into the basic mechanisms by which RF fields interact with developing tissues in an embryo. To evaluate the possible tissue and DNA damage in developing liver of chick embryo following chronic exposure to Ultra-High Frequency/Radiofrequency Radiation (UHF/RFR) emitted from 2G and 3G cell phone. Fertilized chick embryos were incubated in four groups. Group A-experimental group exposed to 2G radiation (60 eggs), Group B- experimental group exposed to 3G radiation (60 eggs), Group C- sham exposed control group (60 eggs) and Group D- control group (48 eggs). On completion of scheduled duration, the embryos were collected and processed for routine histological studies to check structural changes in liver. The nuclear diameter and karyorrhexis changes of hepatocytes were analysed using oculometer and square reticule respectively. The liver procured from one batch of eggs from all the four groups was subjected to alkaline comet assay technique to assess DNA damage. The results were compared using one-way ANOVA test. In our study, the exposure of developing chick embryos to 2G and 3G cell phone radiations caused structural changes in liver in the form of dilated sinusoidal spaces with haemorrhage, increased vacuolations in cytoplasm, increased nuclear diameter and karyorrhexis and significantly increased DNA damage. The chronic exposure of chick embryo liver to RFR emitted from 2G and 3G cell phone resulted in various structural changes and DNA damage. The changes were more pronounced in 3G experimental group. Based on these findings it is necessary to create awareness among public about the possible ill effects of RFR exposure from cell phone.

The effects of Vitamin C on sperm quality parameters in laboratory rats following long-term exposure to cyclophosphamide.

PubMed

Shabanian, Sheida; Farahbod, Farnoosh; Rafieian, Mahmoud; Ganji, Forouzan; Adib, Afshin

2017-01-01

Cyclophosphamide is a widely used medication and can cause oxidative stress. This study was conducted to investigate the effects of Vitamin C on reproductive organs' weight and the quality of sperm parameters in laboratory rats. In this experimental study, 40 rats were randomly assigned into five groups of eight each. Distilled water (DW) group received only food and water, Group 2 was administered with drug solvent (DW) by gavage, Group 3 intraperitoneally administered with 1.6 mg/kg cyclophosphamide, Group 4 gavaged Vitamin C at 0.88 mg/kg, and Group 5 administered with effective doses of Vitamin C and cyclophosphamide by gavage with 1-h intervals. Sperm parameters of the samples were taken from distal epididymis and tissues were studied, and the data were analyzed by SPSS version 22. The lowest weight of testicles and epididymis was seen in cyclophosphamide-exposed rats and the highest weight of testicles and epididymis in Vitamin C-exposed rats ( P < 0.05). The highest motility, progression, viability, and count of sperm were seen in the Vitamin C-treated group and the lowest in the cyclophosphamide-exposed group. The highest proportion of sperm anomalies was seen in the cyclophosphamide-exposed group. Vitamin C, as an antioxidant, can be effective on some of the sperm parameters and can reduce cyclophosphamide-induced complications in animal model.

The effects of Vitamin C on sperm quality parameters in laboratory rats following long-term exposure to cyclophosphamide

PubMed Central

Shabanian, Sheida; Farahbod, Farnoosh; Rafieian, Mahmoud; Ganji, Forouzan; Adib, Afshin

2017-01-01

Cyclophosphamide is a widely used medication and can cause oxidative stress. This study was conducted to investigate the effects of Vitamin C on reproductive organs' weight and the quality of sperm parameters in laboratory rats. In this experimental study, 40 rats were randomly assigned into five groups of eight each. Distilled water (DW) group received only food and water, Group 2 was administered with drug solvent (DW) by gavage, Group 3 intraperitoneally administered with 1.6 mg/kg cyclophosphamide, Group 4 gavaged Vitamin C at 0.88 mg/kg, and Group 5 administered with effective doses of Vitamin C and cyclophosphamide by gavage with 1-h intervals. Sperm parameters of the samples were taken from distal epididymis and tissues were studied, and the data were analyzed by SPSS version 22. The lowest weight of testicles and epididymis was seen in cyclophosphamide-exposed rats and the highest weight of testicles and epididymis in Vitamin C-exposed rats (P < 0.05). The highest motility, progression, viability, and count of sperm were seen in the Vitamin C-treated group and the lowest in the cyclophosphamide-exposed group. The highest proportion of sperm anomalies was seen in the cyclophosphamide-exposed group. Vitamin C, as an antioxidant, can be effective on some of the sperm parameters and can reduce cyclophosphamide-induced complications in animal model. PMID:28516060

Behavioural and biochemical stress responses of Palinurus elephas after exposure to boat noise pollution in tank.

PubMed

Filiciotto, Francesco; Vazzana, Mirella; Celi, Monica; Maccarrone, Vincenzo; Ceraulo, Maria; Buffa, Gaspare; Di Stefano, Vincenzo; Mazzola, Salvatore; Buscaino, Giuseppa

2014-07-15

This study examined the effects of boat noise on the behavioural and biochemical parameters of the Mediterranean spiny lobster (Palinurus elephas). The experiment was conducted in a tank equipped with a video and audio recording system. 18 experimental trials, assigned to boat noise and control conditions, were performed using lobsters in single and group of 4 specimens. After a 1h habituation period, we audio- and video-recorded the lobsters for 1h. During the experimental phase, the animals assigned to the boat groups were exposed to boat noise pollution (a random sequence of boat noises). Exposure to the noise produced significant variations in locomotor behaviours and haemolymphatic parameters. Our results indicate that the lobsters exposed to boat noises increased significantly their locomotor activities and haemolymphatic bioindicator of stressful conditions such as glucose, total proteins, Hsp70 expression and THC when tested both singly and in groups. Copyright © 2014 Elsevier Ltd. All rights reserved.

Altering the Rate of Mitosis by Introducing Low-Gigahertz Radiation to Saccharomyces cerevisiae Cells

NASA Astrophysics Data System (ADS)

Garg, S.; Ashby, C.

2017-12-01

This experiment aims to assess the impact of low-frequency radiation (from common technological tools such as cell phones, scanners, and wifi) on the mitotic rates of cells. In particular, the focus of the study was on the growth and development of Saccharomyces cerevisiae cultures that were exposed to radio waves from a wifi router, which were then compared to a cohort of the same species without exposure. Though routers emit a low gigahertz frequency, they are categorized as Group 2B radiation (possibly carcinogenic) by the International Agency for Research on Cancer of the World Health Organization, signifying that constant exposure poses a potential risk to humans. Twelve agar dishes of active Saccharomyces cerevisiae solution were prepared, with six dishes acting as the control under no added radiation and six acting as the experimental group under 2.4 GHz of radiation due to their proximity to the router. Data on how many cultures proliferated in each dish was collected every three days, with the experiment running for a total of twelve days. All subjects experienced growth curves until day 9 when the experimental group's growth peaked with an average of 62 colonies/dish. Three of the six dishes in this group lost colonies in the following three days, leaving the experimental group with an average of 61 colonies/dish on day 12, while the control group was still increasing by day 12 with an average of 48 colonies/dish, with only one dish undergoing a loss of colonies. Exposing the Saccharomyces cerevisiae cells to low grade radiation resulted in accelerated mitosis, and though the experimental group faced colony death after nine days, the loss was likely due to overpopulation in the dish.

The Effect of Illustrations on Second Graders' Reading Comprehension.

ERIC Educational Resources Information Center

Parisi, Gina

A study investigated whether text illustrations improve the reading comprehension of second graders. Subjects, 14 second-grade students, read five stories from a basal reader. The control group read each story with accompanying illustrations, while the experimental group was exposed to only the written version of the same stories. Questions based…

Results and Implications of a Problem-Solving Treatment Program for Obesity.

ERIC Educational Resources Information Center

Mahoney, B. K.; And Others

Data are from a large scale experimental study which was designed to evaluate a multimethod problem solving approach to obesity. Obese adult volunteers (N=90) were randomly assigned to three groups: maximal treatment, minimal treatment, and no treatment control. In the two treatment groups, subjects were exposed to bibliographic material and…

Effects of a Persuasive Communication on Beliefs, Attitudes, and Career Choice.

ERIC Educational Resources Information Center

Strader, Marlene K.; Katz, Barry M.

1990-01-01

Uses Martin Fishbein's Theory of Reasoned Action to formulate a persuasive communication to influence unclassified U.S. college students to consider a career as a registered nurse. Finds the experimental group shows a significant positive change in beliefs, attitudes, and intentions, unlike the control group exposed to a neutral message only. (NL)

Impulsive choice and pre-exposure to delays: iv. effects of delay- and immediacy-exposure training relative to maturational changes in impulsivity.

PubMed

Renee Renda, C; Rung, Jillian M; Hinnenkamp, Jay E; Lenzini, Stephanie N; Madden, Gregory J

2018-04-23

Impulsive choice describes preference for smaller, sooner rewards over larger, later rewards. Excessive delay discounting (i.e., rapid devaluation of delayed rewards) underlies some impulsive choices, and is observed in many maladaptive behaviors (e.g., substance abuse, gambling). Interventions designed to reduce delay discounting may provide therapeutic gains. One such intervention provides rats with extended training with delayed reinforcers. When compared to a group given extended training with immediate reinforcers, delay-exposed rats make significantly fewer impulsive choices. To what extent is this difference due to delay-exposure training shifting preference toward self-control or immediacy-exposure training (the putative control group) shifting preference toward impulsivity? The current study compared the effects of delay- and immediacy-exposure training to a no-training control group and evaluated within-subject changes in impulsive choice across 51 male Wistar rats. Delay-exposed rats made significantly fewer impulsive choices than immediacy-exposed and control rats. Between-group differences in impulsive choice were not observed in the latter two groups. While delay-exposed rats showed large, significant pre- to posttraining reductions in impulsive choice, immediacy-exposed and control rats showed small reductions in impulsive choice. These results suggest that extended training with delayed reinforcers reduces impulsive choice, and that extended training with immediate reinforcers does not increase impulsive choice. © 2018 Society for the Experimental Analysis of Behavior.

The effect of ethanol vapour exposure on atrial and ventricular walls of chick embryos.

PubMed

Kamran, Kiran; Khan, Muhammad Yunus; Minhas, Liaqat Ali

2016-10-01

To study the effects of ethanol vapour exposure on atrial and ventricular walls of heart in chick embryo. The study design was experimental, conducted at Islamabad Centre of College of Physicians and Surgeons, Pakistan. One hundred and eighty chicken eggs were divided into two groups, experimental and control, of 90 eggs each. Each group was subdivided into three subgroups of 30 eggs each based on the day of sacrifice. Experimental group was exposed to ethanol vapours and then compared with age matched controls. The thickness of atrial and ventricular walls along with lengths of valvular cusps increased in hearts of day 7 and day 10 chick embryos in experimental group. There was thinning of walls and decreased length of valvular cusps in hearts of experimental chicks on hatching as compared to age matched controls. Ethanol vapour exposure during development causes cardiac and septal wall thickening during initial days of development followed by cardiac and septal wall thinning which is a classical picture of alcohol induced cardiomyopathies.

[The characteristics of type I, III collagen and LN in pulmonary fibrosis induced by uranium ore dust in rats].

PubMed

Hu, Ying-chun; Luo, Zhen-hua; Yuan, Xing-jiang; Yang, Li-ping; Wang, Shou-feng; Li, Guang-yue; He, Xing-peng

2011-02-01

To explore the characteristics of LN and type I, III collagen in pulmonary fibrosis induced by uranium ore dust in rats. 60 adult Wistar rats were divided randomly into two groups, control group (30 rats) and uranium ore dust group (30 rats). Non-exposed intratracheal instillation method was used. Uranium ore dust group was exposed 20 mg/ml uranium ore dust suspension 1ml per rat, meanwhile control group was exposed normal saline 1ml per rat. Post-exposed the 7, 14, 21, 30 and 60 d, 6 rats in each group were killed randomly, lung tissue were collected. The pathological changes in lung tissue were observed by microscope using HE staining, the collagen I and III in lungs were observed by polarizing microscope using Biebrich scarlet staining. The expression of LN protein in lung tissue was observed by immunohistochemistry-SP. During lung fibrosis, a large amount of the proliferated I and III collagen in lungs were observed. Post-exposure to uranium ore dust, the characteristics in proliferated collagen in lungs were type I collagen deposited in lung interstitium mainly in the early stage. The area percentage of collagen I and III was increased significantly at 7, 14, 21, 30 and 60d in the experimental group as compared with that in the control group (P < 0.05 or P < 0.01). The over expression of LN in the lung tissue were observed. The expression of LN was distributed in the lung tissue as thickening of the linear or cluster. The integral optical density of LN was increased significantly at 21, 30 and 60 d in the experimental group as compared with that in the control group (P < 0.05 or P < 0.01). After exposure to uranium ore dust, the characteristics in proliferated collagen in lungs are the type of I collagen deposited in lung interstitium mainly in the early stage, while the type of III collagen increase significantly at the later period. The overexpression of LN exists in the process of pulmonary fibrosis. It suggests that LN has a role effect in the process of pulmonary fibrosis.

Effects of Lecture, Teacher Demonstrations, Discussion and Practical Work on 10th Graders' Attitudes to Chemistry and Understanding of Electrolysis.

ERIC Educational Resources Information Center

Thompson, Jerome; Soyibo, Kola

2002-01-01

Investigates whether the use of the combination of lecture, teacher demonstrations, class discussion, and student practical work in small groups significantly improved experimental subjects' attitudes to chemistry and understanding of electrolysis more than their control group counterparts who were not exposed to practical work. Examines whether…

The Effect of an Embedded Pedagogical Agent on the Students' Science Achievement

ERIC Educational Resources Information Center

Kizilkaya, Gonca; Askar, Petek

2008-01-01

Purpose: The purpose of this paper is to investigate the effect of an embedded pedagogical agent into a tutorial on achievement. Design/methodology/approach: Research methodology is designed according to the post test control group model in which the experimental group (69 students) was exposed to a tutorial with an embedded pedagogical agent;…

A Field Study of Performance Among Embarked Infantry Personnel Exposed to Waterborne Motion

DTIC Science & Technology

2012-09-01

was designed with four groups with 16 participants per group to accommodate the calculated sample size and the maximum seating capacity of the...25  A.  APPROACH TO THE EXPERIMENTAL DESIGN .................................25  B.  VARIABLES...39  viii 1.  Design of the Training Period ...........................................................39  2.  Training Period

Field and Laboratory Decay Evaluations of wood-plastic Composites

Treesearch

Rebecca E. Ibach; Marek Gnatowski; Grace Sun

2013-01-01

Experimental wood–plastic composites (WPCs) were made so that they matched the manufacturing process, dimensions, and water absorption of some commercial decking boards. WPC samples from selected formulations were divided into two identical groups. The first group was exposed in exterior conditions in Vancouver, British Columbia, and Hilo, Hawaii, at sun and shadow...

Using constructivist teaching strategies in high school science classrooms to cultivate positive attitudes toward science

NASA Astrophysics Data System (ADS)

Heron, Lory Elen

This study investigated the premise that the use of constructivist teaching strategies (independent variable) in high school science classrooms can cultivate positive attitudes toward science (dependent variable) in high school students. Data regarding the relationship between the use of constructivist strategies and change in student attitude toward science were collected using the Science Attitude Assessment Tool (SAAT) (Heron & Beauchamp, 1996). The format of this study used the pre-test, post-test, control group-experimental group design. The subjects in the study were high school students enrolled in biology, chemistry, or environmental science courses in two high schools in the western United States. Ten teachers and twenty-eight classes, involving a total of 249 students participated in the study. Six experimental group teachers and four control group teachers were each observed an average of six times using the Science Observation Guide (Chapman, 1995) to measure the frequency of observed constructivist behaviors. The mean for the control group teachers was 12.89 and the mean for experimental group teachers was 20.67; F(1, 8) = 16.2, p =.004, revealing teaching behaviors differed significantly between the two groups. After a four month experimental period, the pre-test and post-test SAAT scores were analyzed. Students received a score for their difference in positive attitude toward science. The null hypothesis stating there would be no change in attitude toward science as a subject, between students exposed to constructivist strategies, and students not exposed to constructivist strategies was rejected F(1, 247) = 8.04, p =.005. The control group had a generally higher reported grade in their last science class than the experimental group, yet the control group attitude toward science became more negative (-1.18) while attitude toward science in the experimental group became more positive (+1.34) after the four-month period. An analysis of positive attitude toward science vs. gender was undertaken. An initial significant difference in positive attitude toward science between females and males in the experimental group was established (p =.05). There was no significant difference in positive attitude toward science between those same females and males after the experimental period. Consistent with other results, attitudes toward science for both males and females in the control group became less positive after the study, while males and females in the experimental group had a more positive attitude toward science after four months of using constructivist strategies. Looking at females only, the control group started out with a significantly more positive attitude toward science (mean = 43.40) compared to the experimental group (mean = 39.26, p =.0261). Although a significant difference in positive attitude between females in both groups was not found after the treatment period, the mean attitude score for females in the experimental group increased 2.044, while the mean attitude score for females in the control group decreased by 1.750. Constructivist strategies and their relationship with fostering positive attitudes toward science, might prove a viable solution for addressing the major concern of gender equity and enrollment in higher level science and mathematics courses.

Teaching of evidence-based medicine to medical students in Mexico: a randomized controlled trial

PubMed Central

2012-01-01

Background Evidence-Based Medicine (EBM) is an important competency for the healthcare professional. Experimental evidence of EBM educational interventions from rigorous research studies is limited. The main objective of this study was to assess EBM learning (knowledge, attitudes and self-reported skills) in undergraduate medical students with a randomized controlled trial. Methods The educational intervention was a one-semester EBM course in the 5th year of a public medical school in Mexico. The study design was an experimental parallel group randomized controlled trial for the main outcome measures in the 5th year class (M5 EBM vs. M5 non-EBM groups), and quasi-experimental with static-groups comparisons for the 4th year (M4, not yet exposed) and 6th year (M6, exposed 6 months to a year earlier) groups. EBM attitudes, knowledge and self-reported skills were measured using Taylor’s questionnaire and a summative exam which comprised of a 100-item multiple-choice question (MCQ) test. Results 289 Medical students were assessed: M5 EBM=48, M5 non-EBM=47, M4=87, and M6=107. There was a higher reported use of the Cochrane Library and secondary journals in the intervention group (M5 vs. M5 non-EBM). Critical appraisal skills and attitude scores were higher in the intervention group (M5) and in the group of students exposed to EBM instruction during the previous year (M6). The knowledge level was higher after the intervention in the M5 EBM group compared to the M5 non-EBM group (p<0.001, Cohen's d=0.88 with Taylor's instrument and 3.54 with the 100-item MCQ test). M6 Students that received the intervention in the previous year had a knowledge score higher than the M4 and M5 non-EBM groups, but lower than the M5 EBM group. Conclusions Formal medical student training in EBM produced higher scores in attitudes, knowledge and self-reported critical appraisal skills compared with a randomized control group. Data from the concurrent groups add validity evidence to the study, but rigorous follow-up needs to be done to document retention of EBM abilities. PMID:23131115

AN EXPERIMENTAL STUDY UTILIZING CLOSED CIRCUIT TELEVISION IN AN INDUSTRIAL ARTS TEAM TEACHING PROGRAM. FINAL REPORT.

ERIC Educational Resources Information Center

JAQUITH, CHARLES E.; AND OTHERS

BASIC OBJECTIVES OF THIS EXPERIMENT WERE TO USE TEAM TEACHING BY TV TO HELP STUDENTS GAIN A REALISTIC VIEW OF THE INDUSTRIAL PROCESS AND OF THE IMPORTANCE OF EDUCATION AND TRAINING FOR PARTICIPATION IN THAT PROCESS. GRADE EIGHT STUDENTS IN AN INDUSTRIAL COMMUNITY WERE PLACED IN AN EXPERIMENTAL AND A CONTROL GROUP, AND EXPOSED TO INSTRUCTION FROM…

Industrial Noise and Tooth Wear - Experimental Study

PubMed Central

Cavacas, Maria Alzira; Tavares, Vitor; Borrecho, Gonçalo; Oliveira, Maria João; Oliveira, Pedro; Brito, José; Águas, Artur; dos Santos, José Martins

2015-01-01

Tooth wear is a complex multifactorial process that involves the loss of hard dental tissue. Parafunctional habits have been mentioned as a self-destructive process caused by stress, which results in hyperactivity of masticatory muscles. Stress manifests itself through teeth grinding, leading to progressive teeth wear. The effects of continuous exposure to industrial noise, a “stressor” agent, cannot be ignored and its effects on the teeth must be evaluated. Aims: The aim of this study was to ascertain the effects of industrial noise on dental wear over time, by identifying and quantifying crown area loss. Material and Methods: 39 Wistar rats were used. Thirty rats were divided in 3 experimental groups of 10 animals each. Animals were exposed to industrial noise, rich in LFN components, for 1, 4 and 7 months, with an average weekly exposure of 40 hours (8h/day, 5 days/week with the weekends in silence). The remaining 9 animals were kept in silence. The areas of the three main cusps of the molars were measured under light microscopy. Statistical analysis used: A two-way ANOVA model was applied at significance level of 5%. Results: The average area of the molar cusps was significantly different between exposed and non-exposed animals. The most remarkable differences occurred between month 1 and 4. The total crown loss from month 1 to month 7 was 17.3% in the control group, and 46.5% in the exposed group, and the differences between these variations were significant (p<0.001). Conclusions: Our data suggest that industrial noise is an important factor in the pathogenesis of tooth wear. PMID:25798052

The Impact of Exposure to Cartoons Promoting Healthy Eating on Children's Food Preferences and Choices.

PubMed

Gonçalves, Sónia; Ferreira, Rita; Conceição, Eva M; Silva, Cátia; Machado, Paulo P P; Boyland, Emma; Vaz, Ana

2018-05-01

This study explored whether a cartoon show with healthy eating messages positively affected children's food choices and food preferences. Experimental between-subjects design. Four elementary schools in Portugal were investigated. Children (aged 4-8 years; n = 142) were randomly assigned to 1 of 2 groups: a comparison group (n = 73) was exposed to cartoons with no reference to food and an intervention group (n = 69) was exposed to cartoons with healthy eating messages. After viewing, each child was given the opportunity to eat ad libitum for 10 minutes from a small selection of snack foods. Number of healthy and unhealthy food items chosen. Food preferences were measured using an adapted version of the Leeds Food Preference Checklist. Generalized linear models were used to test for differences between groups. Results were considered significant at P ≤ .05. Children in the experimental group chose significantly more healthy food items than did those in the comparison group (B = -.600; SE = .19; P < .05). Future studies may address the effect of prolonged exposure to healthy eating cartoons. Cartoons can be used to promote healthy food choices and can be a part of health promotion campaigns. Copyright © 2018 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Vaccination against bovine schistosomiasis japonica with highly X-irradiated schistosomula

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsue, S.Y.; Hsue, H.F.; Xu, S.T.

1983-03-01

Cercariae of the Chinese mainland strain of Schistosoma japonicum were used. Eighteen cattle, divided into six groups of three each, were immunized with schistosomula transformed from cercariae exposed to three different doses of X-irradiation (24, 36, and 48 kR). The immunization was given either once, twice, or thrice, and the number of immunizing schistosomula was 10,000 or more in each immunization. The immunized cattle were challenged with 500 normal cercariae. Five native cattle were similarly infected with normal cercariae as controls. All cattle were killed 32-33 days after challenge or infection, and the worms were obtained by perfusion. The meanmore » worm reduction in the 18 experimental animals varied from 42.1 to 96.0%. The mean percent worm reduction of the six experimental groups varied from 54.8 to 87.1. The reduction was greater with increasing numbers of immunizations, and was higher in the groups immunized with schistosomula exposed to 36 kR than in those exposed to 24 or 48 kR. Statistical analyses showed that all immunized groups yielded significantly fewer worms than controls. However, the three doses of X-irradiation (24, 36, and 48 kR) had no significant effect for a fixed number of immunizations (1, 2, or 3). The means for both two and three immunizations were significantly different from the mean for one immunization, although they were not significantly different from each other.« less

Attenuation by intravenous 2-chloroadenosine of acute lung injury induced by live escherichia coli or latex particles added to endotoxin in the neutropenic state.

PubMed

Sakamaki, Fumio; Ishizaka, Akitoshi; Urano, Tetsuya; Sayama, Koichi; Nakamura, Hidetoshi; Terashima, Takeshi; Waki, Yasuhiro; Soejima, Kenzo; Tasaka, Sadatomo; Sawafuji, Makoto; Kobayashi, Kouichi; Yamaguchi, Kazuhiro; Kanazawa, Minoru

2003-08-01

Although neutrophil depletion can reduce the level of acute lung injury (ALI) induced by Escherichia coli endotoxin, that induced by live E coli cannot be attenuated even in neutropenia. This suggests that live E coli cause ALI by way of an mechanism independent of circulating neutrophil. Tumor necrosis factor-alpha (TNF-alpha), which is released from monocytes and macrophages, is a proinflammatory cytokine that is recognized as a central mediator of several forms of inflammation. In this controlled experimental study, we examined the effects of an adenosine-receptor agonist, 2-chloroadenosine (2CA), that has suppressive effects on various cell types and TNF-alpha, on endotoxin plus latex particles, and on ALI induced by live E coli in the neutropenic state. We studied 42 guinea pigs rendered neutropenic by means of intraperitoneal cyclophosphamide administration. Experimental groups consisted of (1) a saline-solution control group; (2) an endotoxin (0.2 mg/kg)-treated group; (3) a group treated with endotoxin plus 2CA (10 micro g/kg); (4) a group treated with latex (2 x 10(9)/kg); (5) a group exposed to endotoxin and latex; (6) a group exposed to endotoxin, latex, and 2CA; (7) a group exposed to E coli (2 x 10(9)/kg); and (8) a group exposed to E coli and 2CA. The injection of endotoxin alone in neutropenic animals did not increase the indexes of ALI (lung tissue/plasma ratio [T/P] and lung wet weight/dry weight ratio [W/D], calculated with the use of iodine 125-labeled albumin). In contrast, these indexes were increased in the endotoxin-and-latex groups compared with those of the control group. ALI in the endotoxin-and-latex group was attenuated by intravenous 2CA. The intravenous injection of live E coli also caused increases in T/P, W/D, and plasma TNF-alpha, but thse were limited by 2CA. In summary, ALI induced by latex particles added to endotoxin and live E coli in the neutropenic state was attenuated by 2CA, suggesting a partial contribution of various cell types or humoral mediators as a neutrophil-independent pathway in its pathogenesis.

[Healing of a deep skin wound using a collagen sponge as dressing in the animal experiment].

PubMed

Sedlarik, K M; Schoots, C; Oosterbaan, J A; Klopper, J P

1992-10-01

The high number of available wound dressing materials as well as the scientific reports about the topic indicates that the problem of an ideal wound dressing is not jet solved. In the last thirty years lot of scientific reports about collagen as wound covering has been published. The positive effect of collagen by his application on a wound ist well known. We investigated the effect of a collagen sponge on healing of full thickness skin wound in guinea pig. The animals were divided in two control groups and two experimental groups. In the control group there were air exposed wounds and another wounds covered with paraffin gauze. In the experimental groups were such wounds covered with natural reconstituted collagen sponge as well as wounds covered with chemically prepared collagen sponge with hexamethyldiisocyanat. The results were compared. The air exposed wounds healed in 50 days, the wounds covered with paraffin gauze healed in 48 days. By covering the wounds with collagen sponge the healing was shortened in 24 or 27 days respectively. Not only the healing time was shortened but also the quality of the wound repair by dressing the wounds with collagen sponge was enhanced.

EDX-Element Analysis of the In Vitro Effect of Fluoride Oral Hygiene Tablets on Artificial Caries Lesion Formation and Remineralization in Human Enamel.

PubMed

Eggerath, J; Kremniczky, T; Gaengler, P; Arnold, W H

2011-01-01

Aim of this in-vitro-study was to assess the remineralization potential of a tooth cleaning tablet with different fluoride content quantitatively using EDX analysis.Twenty three caries free impacted third molars were examined; enamel surfaces were wax coated leaving two 3x4mm windows for exposure to demineralization/remineralization cycles. The teeth were randomly assigned to 4 groups of 5 control and 6 experimental teeth each. Demineralization by standardized HEC-gel, pH 4.7 at 37°C for 72h, was alternated by rinsing in remineralization solution, pH 7.0 at 37°C for 72h, total challenge time 432h. The negative control group N was treated during remineralization cycles with saline; positive control group P was treated with remineralization solution; experimental group D1 was exposed to remineralization solution containing Denttabs(®)-tablets with 1450 ppm F; experimental group D2 was exposed to remineralization solution and Denttabs(®)-tablets with 4350 ppm F. Each tooth was cut into serial sections and analyzed by scanning electron microscopy with EDX element analysis for assessment of the different zones of the lesions in 3 representative sections. Statistical analysis was based on the AVOVA test for repeated measurements and post hoc Bonferroni adjustment. The results showed a significantly higher Ca and P content in the body of the lesion in both fluoride treated groups compared to the controls. It can be concluded that higher concentrations of NaF may be more effective in remineralization of early advanced caries lesions.

EDX-Element Analysis of the In Vitro Effect of Fluoride Oral Hygiene Tablets on Artificial Caries Lesion Formation and Remineralization in Human Enamel

PubMed Central

Eggerath, J; Kremniczky, T; Gaengler, P; Arnold, W.H

2011-01-01

Aim of this in-vitro-study was to assess the remineralization potential of a tooth cleaning tablet with different fluoride content quantitatively using EDX analysis. Twenty three caries free impacted third molars were examined; enamel surfaces were wax coated leaving two 3x4mm windows for exposure to demineralization/remineralization cycles. The teeth were randomly assigned to 4 groups of 5 control and 6 experimental teeth each. Demineralization by standardized HEC-gel, pH 4.7 at 37°C for 72h, was alternated by rinsing in remineralization solution, pH 7.0 at 37°C for 72h, total challenge time 432h. The negative control group N was treated during remineralization cycles with saline; positive control group P was treated with remineralization solution; experimental group D1 was exposed to remineralization solution containing Denttabs®-tablets with 1450 ppm F; experimental group D2 was exposed to remineralization solution and Denttabs®-tablets with 4350 ppm F. Each tooth was cut into serial sections and analyzed by scanning electron microscopy with EDX element analysis for assessment of the different zones of the lesions in 3 representative sections. Statistical analysis was based on the AVOVA test for repeated measurements and post hoc Bonferroni adjustment. The results showed a significantly higher Ca and P content in the body of the lesion in both fluoride treated groups compared to the controls. It can be concluded that higher concentrations of NaF may be more effective in remineralization of early advanced caries lesions. PMID:21687564

Maternal Voice and Short-Term Outcomes in Preterm Infants

PubMed Central

Krueger, Charlene; Parker, Leslie; Chiu, Sheau-Huey; Theriaque, Douglas

2013-01-01

This study explored effects of exposure to maternal voice on short-term outcomes in very low birth weight preterm infants cared for within an neonatal intensive care unit (NICU) without an ongoing program of developmental care. Using a comparative design, 53 infants born during their 27th to 28th postmenstrual week were sampled by convenience. Experimental groups were exposed to maternal voice during two developmental time periods. Group 1 listened to a recording of their mothers reciting a rhyme from 28 to 34 postmenstrual weeks. Group 2 waited 4 weeks and heard the recording from 32 to 34 weeks. The control group received routine care. The primary analysis of combined experimental groups compared to the control group revealed that the experimental infants experienced significantly fewer episodes of feeding intolerance and achieved full enteral feeds quicker compared to the control group. Further, in an analysis evaluating all three groups separately, it was noted that Group 1 experienced significantly fewer episodes of feeding intolerance compared to the control group. Study findings warrant further investigation of exposure to maternal voice and the developmental timing at which exposure is begun. PMID:20112262

Responses of dairy heifers to the visual cliff formed by a herringbone milking pit: evidence of fear of heights in cows (Bos taurus).

PubMed

Arnold, Naomi Adele; Ng, Kim Tee; Jongman, Ellen Caroline; Hemsworth, Paul Hamilton

2007-11-01

The ability of cows (Bos taurus) to perceive depth has never been experimentally investigated. If cows can perceive depth, the milking pit in commercial milking facilities may be fear provoking for dairy cows, as past research has shown that most land-dwelling species possess an instinctive fear of heights. In the current study, 12 dairy heifers (1-year-old cows) were exposed to a milking pit (depth-exposed group) and 13 heifers (control group) were exposed to a standard change in the environment while they moved through a milking facility over a 5-day treatment period. Heifers in the depth-exposed group showed a higher heart rate (p < .05) and stopped more often (p < .05) than did those in the control group; persistence of heart rate but not of behavioral responses on repeated exposures indicated that some habituation to the depth stimulus had occurred. Depth exposure had no effect on cortisol concentrations or on ease of handling. These results indicate that heifers responded differently to a change in depth than they did to a standard change in the environment and provide evidence of both depth perception and acute fear of heights in cows. Copyright 2007 APA.

Neopterin: A candidate biomarker for the early assessment of toxicity of aluminum among bauxite dust exposed mine workers

PubMed Central

Pingle, Shubhangi K.; Thakkar, Lucky R.; Jawade, Aruna A.; Tumane, Rajani G.; Jain, Ruchika K.; Soni, Pravin N.

2015-01-01

Introduction: Bauxite ore is a major source of aluminum (Al) which contains approximately 35–60% Al by weight. Occupational and environmental bauxite dust exposure may cause toxicity by interaction with human biological systems resulting in oxidative stress (OS) and cell death. A neopterin derivative as an antioxidant is able to modulate cytotoxicity by the induction of OS. Materials and Methods: A total of 273 subjects were selected for blood collection from three different major Al producing bauxite mines and were categorized into three groups as experimental (Exp) (n = 150), experimental controls (ExC) (n = 73) and control (Con) (n = 50). Whole blood and serum samples were used for measurement of Al, neopterin, urea and creatinine values. Statistical analysis was performed using R-2.15.1 programming language. Results and Discussion: The result showed that age, body mass index and the behavioral habits, that is, smoking, tobacco and alcohol consumption have possible effects on neopterin level. Serum neopterin levels were found to be significantly higher (P <0.0001) in the experimental group as compared to other groups. Significantly positive correlation (P < 0.0001) was observed between neopterin and creatinine. It was also observed that neopterin level increases as the duration of exposure increases. Conclusion: On the basis of findings it was concluded that exposure to bauxite dust (even at low levels of Al) changes biochemical profile leading to high levels of serum neopterin. Levels of serum neopterin in workers exposed to bauxite dust were probably examined for the 1st time in India. The outcome of this study suggested that serum neopterin may be used as potential biomarker for early detection of health risks associated with bauxite dust exposed population. PMID:26500413

Can healthy, young adults uncover personal details of unknown target individuals in their dreams?

PubMed

Smith, Carlyle

2013-01-01

We investigated the possibility that undergraduate college students could incubate dreams containing information about unknown target individuals with significant life problems. In Experiment 1, students provided two baseline dreams. They were then exposed to a photo of an individual and invited to dream about a health problem (unknown to them and the experimenter) of that individual and asked to provide two more dreams. From a class of 65 students, 12 dreamers volunteered dreams about the unknown target. In Experiment 2, 66 students were asked to dream about the life problems of a second individual, simply by looking at the photo (experimental group). Another 56 students were exposed to this same paradigm, but the photo that they examined was computer generated and the target individual was fictitious (control group). The dream elements were objectively scored with categories devised using the Hall-Van de Castle system as a model. Data were ordinal, and the nonparametric Wilcoxon signed rank test was used to examine preincubation (baseline) versus postincubation (photo examination and incubation) dream content in Experiment 1. In Experiment 2, a Z score for proportions was used to compare differences in frequency of devised categories between experimental and control groups. In Experiment 1, the comparison of postincubation dreams (all categories combined) was significant compared with the preincubation dreams (Z = 2.09, P = .036). The postincubation dreams reflected the health problem of the target. In Experiment 2, the proportion of scored categories in experimental and control groups were compared at the preincubation and postincubation conditions. The proportions of "Combined" (all categories) was very significantly larger at the postincubation condition (Z = 6.27, P < .00001). The groups did not differ at the preincubation condition (Z = -1.12, not significant). Individual postincubation condition comparisons of the experimental versus control groups revealed significant differences in three of the devised scoring categories, ranging from P < .002 to P < .05. There were no experimental versus control preincubation differences. The postincubation dreams of the experimental group were related to the problems of the target individual. Young, healthy adults are capable of dreaming details about the personal problems of an unknown individual simply by examining a picture of the target and then planning to dream about that individual's problems. Copyright © 2013 Elsevier Inc. All rights reserved.

Immunoblot analysis of immunoglobulin G response to the Lyme disease agent (Borrelia burgdorferi) in experimentally and naturally exposed dogs.

PubMed Central

Greene, R T; Walker, R L; Nicholson, W L; Heidner, H W; Levine, J F; Burgess, E C; Wyand, M; Breitschwerdt, E B; Berkhoff, H A

1988-01-01

Immunoblots were used to study the immunoglobulin G response to Borrelia burgdorferi in experimentally and naturally exposed dogs. Adsorption studies confirmed that the antibodies were specific for B. burgdorferi. Experimentally exposed dogs were asymptomatic. Naturally exposed dogs included both asymptomatic animals and animals showing signs compatible with Lyme disease. Naturally exposed dogs were from four geographic regions of the country. No differences were detected between immunoblot patterns of naturally exposed symptomatic or asymptomatic dogs from different areas of the country. The immunoblot patterns obtained with sera from experimentally exposed dogs were different from those obtained with sera from naturally exposed dogs and were characterized by reactivity to fewer and different protein bands. Immunoblot analysis using an OspA-protein-producing Escherichia coli recombinant showed that experimentally exposed dogs produced antibodies to OspA, whereas naturally exposed dogs did not. Modifications of the immune response over time, different routes of antigen presentation, and strain variation are factors postulated to account for the observed differences. Images PMID:3366860

Bee products prevent agrichemical-induced oxidative damage in fish.

PubMed

Ferreira, Daiane; Rocha, Helio Carlos; Kreutz, Luiz Carlos; Loro, Vania Lucia; Marqueze, Alessandra; Koakoski, Gessi; da Rosa, João Gabriel Santos; Gusso, Darlan; Oliveira, Thiago Acosta; de Abreu, Murilo Sander; Barcellos, Leonardo José Gil

2013-01-01

In southern South America and other parts of the world, aquaculture is an activity that complements agriculture. Small amounts of agrichemicals can reach aquaculture ponds, which results in numerous problems caused by oxidative stress in non-target organisms. Substances that can prevent or reverse agrichemical-induced oxidative damage may be used to combat these effects. This study includes four experiments. In each experiment, 96 mixed-sex, 6-month-old Rhamdia quelen (118±15 g) were distributed into eight experimental groups: a control group that was not exposed to contaminated water, three groups that were exposed to various concentrations of bee products, three groups that were exposed to various concentrations of bee products plus tebuconazole (TEB; Folicur 200 CE™) and a group that was exposed to 0.88 mg L(-1) of TEB alone (corresponding to 16.6% of the 96-h LC50). We show that waterborne bee products, including royal jelly (RJ), honey (H), bee pollen (BP) and propolis (P), reversed the oxidative damage caused by exposure to TEB. These effects were likely caused by the high polyphenol contents of these bee-derived compounds. The most likely mechanism of action for the protective effects of bee products against tissue oxidation and the resultant damage is that the enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) are increased.

Evidence relevant to untargeted and transgenerational effects in the offspring of irradiated parents

PubMed Central

Little, Mark P.; Goodhead, Dudley T.; Bridges, Bryn A.; Bouffler, Simon D.

2013-01-01

In this article we review health effects in offspring of human populations exposed as a result of radiotherapy and some groups exposed to chemotherapy. We also assess risks in offspring of other radiation-exposed groups, in particular those of the Japanese atomic bomb survivors and occupationally and environmentally exposed groups. Experimental findings are also briefly surveyed. Animal and cellular studies tend to suggest that the irradiation of males, at least at high doses (mostly 1 Gy and above), can lead to observable effects (including both genetic and epigenetic) in the somatic cells of their offspring over several generations that are not attributable to the inheritance of a simple mutation through the parental germ line. However, studies of disease in the offspring of irradiated humans have not identified any effects on health. The available evidence therefore suggests that human health has not been significantly affected by transgenerational effects of radiation. It is possible that transgenerational effects are restricted to relatively short times post-exposure and in humans conception at short times after exposure is likely to be rare. Further research that may help resolve the apparent discrepancies between cellular/animal studies and studies of human health are outlined. PMID:23648355

Supplementation with Silk Amino Acids improves physiological parameters defining stamina in elite fin-swimmers.

PubMed

Zubrzycki, Igor Z; Ossowski, Zbigniew; Przybylski, Stanislaw; Wiacek, Magdalena; Clarke, Anna; Trabka, Bartosz

2014-01-01

Previous animal study has shown that supplementation with silk amino acid hydrolysate (SAA) increases stamina in mice. The presented study was the first formal evaluation of the influence of SAA supplementation on parameters defining physiological fitness level in humans. It was a randomized controlled trial with a parallel-group design on elite male fin-swimmers. The experimental group was supplemented with 500 mg of SAA per kg of body mass, dissolved in 250 ml of a Carborade Drink®; the control group with Carborade Drink® alone; 3 times a day, 30 minutes prior to the training session. Changes discerned in the experimental group were more pronounced than those observed in the control group. For example, the change in the serum lactic acid concentration observed in the experimental group was sevenfold less than in the control group [21.8 vs. -3.7 L% for the control and experimental groups, respectively]. An analysis of a lactate profile as a function of a maximal swimming velocity exposed a statistically significant positive shift in the swimming velocity of 0.05 m/s, at the lactate concentration of 4 mmol/L in the experimental group. There was also a positive, although statistically insignificant, increase of 2.6 L% in serum testosterone levels in the experimental group. This study showed that a 12-day SAA supplementation combined with an extensive and rigorous training schedule was sufficient to increase an aerobic stamina. However, this phenomenon was associated with an augmented level of muscular damage (an increased level of creatine phosphokinase in the experimental group).

In vitro effect of fluoride oral hygiene tablets on artificial caries lesion formation and remineralization in human enamel

PubMed Central

Gängler, Peter; Kremniczky, Thomas; Arnold, Wolfgang H

2009-01-01

Background Aim of this in-vitro-study was to assess the remineralization potential of a tooth cleaning tablet with different fluoride content. Methods Twenty three caries free impacted third molars were examined, enamel surfaces were wax coated leaving two 3 × 4 mm windows for exposure to demineralization/remineralization cycles. The teeth were randomly assigned to 4 groups of 5 control and 6 experimental teeth. Demineralization by standardised HEC-gel, pH 4.7 at 37°C for 72 h, was alternated by rinsing in remineralization solution, pH 7.0 at 37°C for 72 h, total challenge time 432 h. The negative control group N was treated during remineralization cycles with saline; positive control group P was treated with remineralization solution; experimental group D1 was exposed to remineralization solution containing Denttabs®-tablets with 1450 ppm F; experimental group D2 was exposed to remineralization solution and Denttabs®-tablets with 4350 ppm F. Each tooth was cut into serial sections and analyzed by polarized light microscopy for assessment of the different zones of white-spot lesions in 3 representative sections. Statistical analysis was based on the Mann-Whitney-Test. Results Both control groups N(-) and P(+) exhibited characteristic white-spot lesions. The remineralization and the demineralization inhibition of the lesions increased considerably from N

Effects of Schistosoma haematobium infection on reproductive success and male outcrossing ability in the simultaneous hermaphrodite, Bulinus truncatus (Gastropoda: Planorbidae).

PubMed

Schrag, S J; Rollinson, D

1994-01-01

The schistosome intermediate snail host, Bulinus truncatus (Mollusca: Planorbidae), has two reproductive (phally) morphs. Both aphallics and euphallics can self-fertilize, but aphallics cannot donate sperm because they do not develop a functional penis and prostate. This study investigated the interactions between phally and fitness consequences of Schistosoma haematobium infection in B. truncatus. Snails which developed patent infections produced 26% fewer eggs than controls and 35% fewer eggs than exposed snails which did not develop infections. This reduction was due to a lower lifetime production of egg masses and a smaller mean number of eggs/mass in infected snails relative to control or exposed snails. However, there was no evidence of increased mortality in infected snails. Contrary to reports of fecundity compensation in other intermediate host snails, egg production post-exposure during the pre-patent period did not increase relative to that of controls in either infected or exposed snails. Phally did not influence susceptibility to infection or length of the prepatent period. Furthermore, lifetime egg, egg mass and hatchling production, as well as mean eggs/mass and number of hatchlings reaching maturity, did not differ significantly between aphallics and euphallics within control of exposed experimental groups. However, within the infected group euphallics produced 38% fewer eggs, smaller egg masses, and fewer hatchlings reaching maturity than aphallics, supporting the prediction of a cost to the growth and maintenance of a full male tract. This cost was detectable only when snails were under the stress of infection. The proportion of euphallic offspring produced did not differ across experimental groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of electromagnetic pulse on serum element levels in rat.

PubMed

Li, Kangchu; Ma, Shirong; Ren, Dongqing; Li, Yurong; Ding, Guirong; Liu, Junye; Guo, Yao; Guo, Guozhen

2014-04-01

Electromagnetic pulse (EMP) was a potentially harmful factor to the human body, and a biological dosimetry to evaluate effects of EMP is necessary. Little is known about effects of EMP on concentration of macro and trace elements in serum so far. In this study, Sprague-Dawley rats were randomly divided into 50-kV/m EMP-exposed group (n = 10), 100-kV/m EMP-exposed group (n = 10), 200-kV/m EMP-exposed group (n = 40), and the sham-exposed group (n = 20). The macro and trace element concentrations in serum were examined at 6, 12, 24, and 48 h after EMP exposure at different electric field intensities. Compared with the sham-exposed groups, the concentration of sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), zinc (Zn), copper (Cu), iron (Fe), selenium (Se), and manganese (Mn) in rat serum was not changed significantly within 48 h after 200 pulses of EMP exposure at electric field intensity of 50, 100, and 200 kV/m although the K level was decreased and the Ca level was increased with the electric field intensity of EMP increasing. In addition, there was a tendency that the Zn level was decreased with the time going on within 48 h after EMP exposure. Under our experimental conditions, EMP exposure cannot affect the concentration of macro and trace elements in rat serum. There was no time-effect or dose-effect relationship between EMP exposure and serum element levels. The macro and trace elements in serum are not suitable endpoints of biological dosimetry of EMP.

Can safe and long-term exposure to extremely low frequency (50 Hz) magnetic fields affect apoptosis, reproduction, and oxidative stress?

PubMed

Akdag, Mehmet Zulkuf; Dasdag, Suleyman; Uzunlar, Ali Kemal; Ulukaya, Engin; Oral, Arzu Yilmaztepe; Çelik, Necla; Akşen, Feyzan

2013-12-01

To determine whether 50 Hz extremely low frequency-magnetic fields (ELF-MF) affects apoptotic processes, oxidative damage, and reproductive characteristics such as sperm count and morphology in rat testes. Thirty male Sprague-Dawley rats were used in the present study, which were divided into three groups (sham group, n = 10, and two experimental groups, n = 10 for each group). Rats in the experimental group were exposed to 100 and 500 μT ELF-MF (2 h/day, 7 days/week, for 10 months) corresponding to exposure levels that are considered safe for humans. The same experimental procedures were applied to the sham group, but the ELF generator was turned off. Tissues from the testes were immunohistochemically stained for active (cleaved) caspase-3 in order to measure the apoptotic index by a semi-quantitative scoring system. The levels of catalase (CAT), malondialdehyde (MDA), myeloperoxidase (MPO), total antioxidative capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) were also measured. Additionally, epididymal sperm count and sperm morphology was evaluated. There were no significant differences in the reproductive and oxidative stress parameters between the sham group and the exposed groups (p > 0.05). While no difference was observed between the final apoptosis score of the sham and the 100 μT ELF-MF group (p > 0.05), the final apoptosis score was higher in the 500 μT ELF-MF exposure group than in the sham group (p < 0.05). Long-term exposure to 100 μT and 500 μT ELF-MF did not affect oxidative or antioxidative processes, lipid peroxidation, or reproductive components such as sperm count and morphology in testes tissue of rats. However, long-term exposure to 500 μT ELF-MF did affect active-caspase-3 activity, which is a well-known apoptotic indicator.

Quantification of peroxide ion passage in dentin, enamel, and cementum after internal bleaching with hydrogen peroxide.

PubMed

Palo, R M; Bonetti-Filho, I; Valera, M C; Camargo, C H R; Camargo, Sea; Moura-Netto, C; Pameijer, C

2012-01-01

The aim of this study was to evaluate the amount of peroxide passage from the pulp chamber to the external enamel surface during the internal bleaching technique. Fifty bovine teeth were sectioned transversally 5 mm below the cemento-enamel junction (CEJ), and the remaining part of the root was sealed with a 2-mm layer of glass ionomer cement. The external surface of the samples was coated with nail varnish, with the exception of standardized circular areas (6-mm diameter) located on the enamel, exposed dentin, or cementum surface of the tooth. The teeth were divided into three experimental groups according to exposed areas close to the CEJ and into two control groups (n=10/group), as follows: GE, enamel exposure area; GC, cementum exposed area; GD, dentin exposed area; Negative control, no presence of internal bleaching agent and uncoated surface; and Positive control, pulp chamber filled with bleaching agent and external surface totally coated with nail varnish. The pulp chamber was filled with 35% hydrogen peroxide (Opalescence Endo, Ultradent). Each sample was placed inside of individual flasks with 1000 μL of acetate buffer solution, 2 M (pH 4.5). After seven days, the buffer solution was transferred to a glass tube, in which 100 μL of leuco-crystal violet and 50 μL of horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to Kruskal-Wallis and Dunn-Bonferroni tests (α=0.05). All experimental groups presented passage of peroxide to the external surface that was statistically different from that observed in the control groups. It was verified that the passage of peroxide was higher in GD than in GE (p<0.01). The GC group presented a significantly lower peroxide passage than did GD and GE (p<0.01). It can be concluded that the hydrogen peroxide placed into the pulp chamber passed through the dental hard tissues, reaching the external surface and the periodontal tissue. The cementum surface was less permeable than were the dentin and enamel surfaces.

Residual oxygen releasing time from dental structure after carbamide peroxide exposure: study of the effects of a neutralizer gel.

PubMed

Salome, Paloma; Bueno, Renata Pla Rizzolo; Nascimento, Paulo Cicero; Pozzobon, Roselaine Terezinha

2012-01-01

The purpose of this article was to assess in vitro the effects of a catalase-based neutralizer gel in the release of residual oxygen in permanent human teeth specimens exposed to 10% carbamide peroxide. Thirty teeth specimens (5.0 x 5.0 x 3.0 mm3) were randomly divided into three groups (n = 10): Group 1, nonbleached negative control specimens; Group 2, bleached positive control specimens; and Group 3, bleached specimens exposed to a catalase-based gel. The bleaching treatment was performed six hours per day for 14 days. At the end of the bleaching treatment, Group 3 specimens were immersed in a receptacle containing the catalase-based experimental gel for three minutes. Titrations were performed to determine the quantity of residual oxygen that each test specimen released, starting immediately after the end of the bleaching treatment and exposure (or not) to the catalase-based gel, and repeated on days 1-5, 10, and 15. The values obtained were statistically analyzed by ANOVA and a Tukey post hoc test (P < 0.05). The release values of residual O2 for Group 2 were equal to those of Group 1 after 10 days and to those of Group 3 after five days. The use of a catalase-based experimental neutralizer gel, applied for three minutes, reduced by half the time required for complete release of residual oxygen from tooth structure after exposure to a 10% carbamide peroxide bleaching agent.

Effects of Hypergravity on Statocyst Development in Embryonic Aplysia californica

NASA Technical Reports Server (NTRS)

Pedrozo, Hugo A.; Wiederhold, Michael L.

1994-01-01

Aplysia californica is a marine gastropod mollusc with bilaterally paired statocysts as gravity-reccptor organs. Data from three experiments in which embryonic Aplysia californica were exposed to 2 x g arc discussed. The experimental groups were exposed to excess gravity until hatching (9-12 day), whereas control groups were maintained at normal gravity. Body diameter was measured before exposure to 2 x g. Statocyst, statolith and body diameter were each determined for samples of 20 embryos from each group on successive days. Exposure to excess gravity led to an increase in body size. Statocyst size was not affected by exposure to 2 x g. Statolith size decreased with treatment as indicated by smaller statolith-to-body ratios observed in the 2 x g group in all three experiments. Mean statolith diameter was significantly smaller for the 2 x g group in Experiment 1 but not in Experiments 2 and 3. Defective statocysts, characterized by very small or no statoliths, were found in the 2 x g group in Experiments 1 and 2.

Cognitive conflict as a teaching strategy in solving chemistry problems: A dialectic-constructivist perspective

NASA Astrophysics Data System (ADS)

Niaz, Mansoor

The main objective of this study was to evaluate the effect of teaching experiments within a dialectic-constructivist framework based on the following considerations: (a) Cognitive conflicts used in the teaching experiments must be based on problem-solving strategies that students find relatively convincing: (b) after having generated a cognitive conflict, it is essential that the students be provided with an experience that could facilitate the resolution of the conflict; and (c) the teaching strategy developed is used by an interactive constructivist approach within an intact classroom. The study was based on two sections of freshman students who had registered for Chemistry I at the Universidad de Oriente, Venezuela. One of the sections was randomly designated as the control group and the other as the experimental group. To introduce cognitive conflict, the experimental group was exposed to two teaching experiments dealing with stoichiometry problems based on the concept of limiting reagent. Students in the control group were exposed to the same problems - however, without the cognitive conflict teaching experiments format. To evaluate the effect of the teaching experiments, both groups were evaluated on five different problems at different intervals during the semester, referred to as posttests. All posttests formed part of the regular evaluation of the students. Results obtained show the advantage of the experimental group on four of the posttests. It is concluded that the experimental treatment was effective in improving performance on the immediate posttests. It was observed that some students protect their core belief [see Lakatos, I. (1970). Falsification and the methodology of scientific research programmes. In I. Lakatos & A. Musgrave (Eds.), Criticism and the growth of knowledge (pp. 91-196). Cambridge: Cambridge University Press] in stoichiometry (establishing equivalent relations between different elements or compounds) by ignoring the conflicting data, just as conflicting (anomalous) data do not necessarily convince a scientist to abandon a particular theory.Received: 23 September 1993; Revised: 29 August 1994;

Effects of Sumsu (Bufonis venenum) Pharmacopuncture Treatment on Depression in Mice.

PubMed

Choi, Min-Ji; Kim, Ka-Na; Lee, Jae-Eun; Suh, Jin-Woo; Kim, Sung-Chul; Kwon, Ki Rok; Cho, Seung-Hun

2014-06-01

The main objective of this study was to evaluate the anti-depressant effects of pharmacopuncture using sumsu (Bufonis venenum). Animals were divided into three groups (control, sham, and experimental), with eight mice per group. The sham and the experimental groups were exposed to 2 hours of immobilization stress daily for 14 days. They were also injected with normal saline (sham) or subjected to pharmacopuncture with sumsu at the acupoints HT7, SP6, and GV20 (experimental). The depression or anxiety-like behaviors of the mice in each group were evaluated 1 day after treatment. There was no difference in locomotor activity between the groups during the open-field test; i.e., all groups had normal motor function. However, the open-field and the forced-swimming tests revealed that depression and anxiety-like behaviors were decreased significantly in the group treated with sumsu pharmacopuncture. Sumsu pharmacopuncture attenuated depressive or anxiety-like behavior in mice stressed with chronic immobilization. These results suggest that sumsu pharmacopuncture has therapeutic potential for treating neuropsychiatric disorders such as anxiety or depression disorder.

Sudden death in epileptic rats exposed to nocturnal magnetic fields that simulate the shape and the intensity of sudden changes in geomagnetic activity: an experiment in response to Schnabel, Beblo and May

NASA Astrophysics Data System (ADS)

Persinger, M. A.; McKay, B. E.; O'Donovan, C. A.; Koren, S. A.

2005-03-01

To test the hypothesis that sudden unexplained death (SUD) in some epileptic patients is related to geomagnetic activity we exposed rats in which limbic epilepsy had been induced to experimentally produced magnetic fields designed to simulate sudden storm commencements (SSCs). Prior studies with rats had shown that sudden death in groups of rats in which epilepsy had been induced months earlier was associated with the occurrence of SSCs and increased geomagnetic activity during the previous night. Schnabel et al. [(2000) Neurology 54:903 908) found no relationship between SUD in human patients and geomagnetic activity. A total of 96 rats were exposed to either 500, 50, 10 40 nT or sham (less than 10 nT) magnetic fields for 6 min every hour between midnight and 0800 hours (local time) for three successive nights. The shape of the complex, amplitude-modulated magnetic fields simulated the shape and structure of an average SSC. The rats were then seized with lithium and pilocarpine and the mortality was monitored. Whereas 10% of the rats that had been exposed to the sham field died within 24 h, 60% of the rats that had been exposed to the experimental magnetic fields simulating natural geomagnetic activity died (P<.001) during this period. These results suggest that correlational analyses between SUD in epileptic patients and increased geomagnetic activity can be simulated experimentally in epileptic rats and that potential mechanisms might be testable directly.

Investigating the Effectiveness of Storylines Embedded within a Context-Based Approach: The Case for the Periodic Table

ERIC Educational Resources Information Center

Demircioglu, Hulya; Demircioglu, Gokhan; Calik, Muammar

2009-01-01

We investigated the effect of the context-based approach on 9th grade students' conceptions of the Periodic Table. Within a nonequivalent pretest-posttest control group design the study was conducted with 80 grade 9 students (aged 15-16) drawn from two classes (39 and 41 students) in a high school in Turkey. The experimental group was exposed to…

Pulmonary function and oxidative stress in workers exposed to styrene in plastic factory: occupational hazards in styrene-exposed plastic factory workers.

PubMed

Sati, Prakash Chandra; Khaliq, Farah; Vaney, Neelam; Ahmed, Tanzeel; Tripathi, Ashok K; Banerjee, Basu Dev

2011-11-01

Styrene is a volatile organic compound used in factories for synthesis of plastic products. The pneumotoxicity of styrene in experimental animals is known. The aim of the present study was to study the effect of styrene on lung function and oxidative stress in occupationally exposed workers in plastic factory. Thirty-four male workers, between 18 and 40 years of age, exposed to styrene for atleast 8 hours a day for more than a year were studied, while 30 age- and sex-matched healthy subjects not exposed to styrene served as controls. Assessment of lung functions showed a statistically significant reduction (p < 0.05) in most of the lung volumes, capacities (FVC, FEV(1), VC, ERV, IRV, and IC) and flow rates (PEFR, MEF(75%), and MVV) in the study group (workers) as compared to controls. Malondialdehyde (MDA) was observed to be significantly high (p < 0.05) while ferric-reducing ability of plasma (FRAP) was significantly low (p < 0.05) in styrene-exposed subjects. Reduced glutathione (GSH) level was significantly depleted in exposed subjects as compared to control group. The mean value of serum cytochrome c in styrene-exposed subjects was found to be 1.1 ng/ml (0.89-1.89) while in control its levels were under detection limit (0.05 ng/ml). It shows that styrene inhalation by workers leads to increased level of oxidative stress, which is supposed to be the cause of lung damage.

erbB expression changes in ethanol and 7, 12- dimethylbenz (a) anthracene-induced oral carcinogenesis

PubMed Central

Jacinto-Alemán, Luis F.; García-Carrancá, Alejandro; Leyba-Huerta, Elba R.; Zenteno-Galindo, Edgar; Jiménez-Farfán, María D.

2013-01-01

Objetive: The aim of this study was to determine erbB expression in normal mucosa, oral dysplasia, and invasive carcinomas developed in the hamster’s buccal pouch chemical carcinogenesis model. Study design: Fifty Syrian golden hamsters were equally divided in five groups (A-E); two controls and three experimental group exposed to alcohol, DMBA, or both for 14 weeks. Number of tumors per cheek, volume, histological condition, erbB expression were determined and results were analyzed by the Mann–Whitney U and Dunn’s test. Results: Control groups and those exposed to alcohol (A, B and C respectively) only presented clinical and histological normal mucosa; while those exposed to DMBA or DMBA plus alcohol (D and E groups) developed dysplasia and invasive carcinomas. erbB2, erbB3, and erbB4 increased their expression in alcohol-exposed mucosa, dysplasia, and invasive carcinomas. We observed a similar expression level for erbB2 in dysplasia and carcinomas; while, erbB3 and erbB4 were similar only in carcinomas. Conclusion: The DMBA and alcohol can be considered as carcinogen and promoter for oral carcinogenesis. The erbB expression is different according to their histological condition, suggesting differential participation of the erbB family in oral carcinogenesis induced by alcohol and DMBA. Key words:erbB, 7,12- dimethylbenz(a)anthracene, oral squamous cell carcinoma. PMID:23229248

Sealing ability of white and gray mineral trioxide aggregate mixed with distilled water and 0.12% chlorhexidine gluconate when used as root-end filling materials.

PubMed

Shahi, Shahriar; Rahimi, Saeed; Yavari, Hamid Reza; Shakouie, Sahar; Nezafati, Saeed; Abdolrahimi, Majid

2007-12-01

This in vitro study used dye penetration to compare the sealing ability of white and gray mineral trioxide aggregate mixed with distilled water and 0.12% chlorhexidine gluconate when used as root-end filling materials. Ninety-six single-rooted human teeth were cleaned, shaped, and obturated with gutta-percha and AH26 root canal sealer. The apical 3 mm of each root was resected, and 3-mm deep root-end cavity preparations were made. The teeth were randomly divided into 4 experimental groups, each containing 20 teeth, and 2 negative and positive control groups, each containing 8 teeth. Root-end cavities in the experimental groups were filled with the experimental materials. After decoronation of the teeth and application of nail polish, the teeth were exposed to India ink for 72 hours and longitudinally sectioned, and the extent of dye penetration was measured with a stereomicroscope. Statistical analysis showed that there were no significant differences among the 4 experimental groups.

The low doses effect of experimental zearalenone (ZEN) intoxication on the presence of Ca2+ in selected ovarian cells from pre-pubertal bitches.

PubMed

Gajecka, M; Przybylska-Gornowicz, B

2012-01-01

The objective of this study was to determine the effect of 42-day ZEN intoxication on the presence of Ca2+ in selected ovarian cells from beagle bitches, using the potassium pyroantimonate (PPA) method. Samples were collected from 30 clinically healthy, pre-pubertal, genetically homogeneous animals. The bitches were divided into three groups of 10 animals each: experimental group I--50 microg ZEN/kg BW (100% NOAEL) administered once daily per os; experimental group II--75 microg ZEN/kg BW (150% NOAEL) administered once dailyper os; control group--placebo containing no ZEN administered per os. An electron microscopic analysis revealed that cells died due to apoptosis, depending on the ZEN dose and the type of cells exposed to intoxication. Lower ZEN doses led to apoptosis-like changes in the cells. Cell death was a consequence of excess Ca2+ accumulation in the mitochondria, followed by cell dysfunction and a decrease in or the absence of mitochondrial metabolic activity in oocytes, follicle cells and interstitial cells in experimental bitches.

Continuous light after a long-day treatment is equivalent to melatonin implants to stimulate testosterone secretion in Alpine male goats.

PubMed

Delgadillo, J A; Vélez, L I; Flores, J A

2016-04-01

In rams, artificial long days followed by continuous light stimulate testosterone secretion during the non-breeding season. The objective of this study was to determine whether artificial long days followed by continuous light could stimulate testosterone secretion in Alpine bucks as well as in those exposed to long days followed by a melatonin treatment. All bucks were kept in shaded open pens. Control males were exposed to natural photoperiod conditions (n=5). Males of the two experimental groups were exposed to 2.5 months of long days from 1 December (n=5 each). On 16 February, one group of males was exposed to 24 h of light per day until 30 June; the other group was exposed to natural variations of photoperiod and received two s.c. melatonin implants. Testicular weight was determined every 2 weeks, and the plasma testosterone concentrations once a week. In the control and the two photoperiodic-treated groups, a treatment×time interaction was detected for testicular weight and plasma testosterone concentrations (P<0.001). In control bucks, testicular weight increased from January and peaked in June, whereas in both photoperiodic-treated groups, this variable increased from January, but peaked in April, when the values were higher than in controls (P<0.05). In the control group, plasma testosterone concentrations remained low from January to June, whereas in both photoperiodic-treated groups, this variable remained low from January to March; thereafter, these levels increased in both photoperiodic-treated groups, and were higher than controls in April and May (P<0.05). We conclude that continuous light after a long-day treatment stimulate testosterone secretion in Alpine male goats during the non-breeding season as well as the long days followed by a melatonin treatment. Therefore, continuous light could replace the implants of melatonin.

Evaluation of motor and cognitive development among infants exposed to HIV.

PubMed

da Silva, Kaitiana Martins; de Sá, Cristina Dos Santos Cardoso; Carvalho, Raquel

2017-02-01

This study of a prospective and cross-sectional nature compared the motor and cognitive development of HIV-exposed and unexposed infants in their first 18months of age. 40 infants exposed to HIV and antiretroviral therapy (Experimental Group - EG) and 40 unexposed infants (Control Group - CG) participated in the study. They were divided into four age groups of 4, 8, 12 and 18months old, with 10 infants from EG and 10 from CG in each group. The infants were evaluated once on motor and cognitive development by the Bayley Scale of Infant and Toddler Development. Performance category grading and comparisons among scaled score, composite score and percentile rank were held. There was significant group effect for scores in motor and cognitive domains showing lower scores for EG regardless of age. In comparison to the CG, the EG presented lower scores for cognitive domain at 8 and 18months. In the performance categories, all infants were classified at or above the average for motor and cognitive development, except of one EG-18month old infant classified as borderline for motor development. Infants exposed to HIV and antiretroviral therapy own adequate cognitive and motor development in the first 18months. However, the lower scores found, particularly on the 8th and 18th month for cognitive development, may indicate future problems, highlighting the need for systematic follow-up of this population. Copyright © 2017 Elsevier B.V. All rights reserved.

Temporal and speech processing skills in normal hearing individuals exposed to occupational noise.

PubMed

Kumar, U Ajith; Ameenudin, Syed; Sangamanatha, A V

2012-01-01

Prolonged exposure to high levels of occupational noise can cause damage to hair cells in the cochlea and result in permanent noise-induced cochlear hearing loss. Consequences of cochlear hearing loss on speech perception and psychophysical abilities have been well documented. Primary goal of this research was to explore temporal processing and speech perception Skills in individuals who are exposed to occupational noise of more than 80 dBA and not yet incurred clinically significant threshold shifts. Contribution of temporal processing skills to speech perception in adverse listening situation was also evaluated. A total of 118 participants took part in this research. Participants comprised three groups of train drivers in the age range of 30-40 (n= 13), 41 50 ( = 13), 41-50 (n = 9), and 51-60 (n = 6) years and their non-noise-exposed counterparts (n = 30 in each age group). Participants of all the groups including the train drivers had hearing sensitivity within 25 dB HL in the octave frequencies between 250 and 8 kHz. Temporal processing was evaluated using gap detection, modulation detection, and duration pattern tests. Speech recognition was tested in presence multi-talker babble at -5dB SNR. Differences between experimental and control groups were analyzed using ANOVA and independent sample t-tests. Results showed a trend of reduced temporal processing skills in individuals with noise exposure. These deficits were observed despite normal peripheral hearing sensitivity. Speech recognition scores in the presence of noise were also significantly poor in noise-exposed group. Furthermore, poor temporal processing skills partially accounted for the speech recognition difficulties exhibited by the noise-exposed individuals. These results suggest that noise can cause significant distortions in the processing of suprathreshold temporal cues which may add to difficulties in hearing in adverse listening conditions.

Effect of parsley (Petroselinum crispum, Apiaceae) juice against cadmium neurotoxicity in albino mice (Mus musculus).

PubMed

Maodaa, Saleh N; Allam, Ahmed A; Ajarem, Jamaan; Abdel-Maksoud, Mostafa A; Al-Basher, Gadah I; Wang, Zun Yao

2016-02-04

Parsley was employed as an experimental probe to prevent the behavioral, biochemical and morphological changes in the brain tissue of the albino mice following chronic cadmium (Cd) administration. Non-anesthetized adult male mice were given parsley juice (Petroselinum crispum, Apiaceae) daily by gastric intubation at doses of 10 and 20 g/kg/day. The animals were divided into six groups: Group A, mice were exposed to saline; Groups B and C, were given low and high doses of parsley juice, respectively; Group D, mice were exposed to Cd; Groups E and F, were exposed to Cd and concomitantly given low and high doses of parsley, respectively. Cd intoxication can cause behavioral abnormalities, biochemical and histopathological disturbances in treated mice. Parsley juice has significantly improved the Cd-associated behavioral changes, reduced the elevation of lipid peroxidation and normalized the Cd effect on reduced glutathione and peroxidase activities in the brain of treated mice. Histological data have supported these foundations whereas Cd treatment has induced neuronal degeneration, chromatolysis and pyknosis in the cerebrum, cerebellum and medulla oblongata. The low dose (5 g/kg/day) of parsley exhibited beneficial effects in reducing the deleterious changes associated with Cd treatment on the behavior, neurotransmitters level, oxidative stress and brain neurons of the Cd-treated mice.

Effects of dietary lead exposure on vitamin levels in great tit nestlings - An experimental manipulation.

PubMed

Ruiz, Sandra; Espín, Silvia; Rainio, Miia; Ruuskanen, Suvi; Salminen, Juha-Pekka; Lilley, Thomas M; Eeva, Tapio

2016-06-01

Exposure to metal pollution negatively affects animal physiology, including nutrient metabolism, but in the wild an effect can seldom be attributed to a single metal. Moreover, little is known about how the metabolism of vitamins, essential micronutrients for developing juveniles, is affected by toxic metals. Therefore we experimentally investigated the effects of lead (Pb), a widespread toxic metal, on four fat-soluble vitamins A (total and retinol), D3, E (total and α-tocopherol) and K and carotenoids (lutein, zeaxanthin and unidentified) in great tit (Parus major) nestlings. In addition to a control group where no Pb was provided, two Pb-dosed groups were compared to a metal exposed group in the vicinity of a Ni-Cu smelter. We examined whether Pb treatment affects vitamin homeostasis and how the response of Pb-treated birds relates to that of a population under industrial exposure of Pb and other metals. For this purpose, vitamin and carotenoid levels were quantified with UPLC-MS from plasma of 7 days-old nestlings. All metal exposed groups showed increased vitamin A and retinol levels. However, vitamin levels were not directly associated with fecal Pb levels, with the exception of retinol, which was positively correlated with fecal Pb. Alpha-tocopherol, lutein and zeaxanthin levels were positively associated with body mass and wing growth rate. To conclude, Pb exposure increased plasma vitamin A and retinol levels while the levels of other vitamins and carotenoids rather reflected secondary pollution effects via differences in habitat and diet quality at the smelter site. Our findings suggest Pb exposed nestlings may allocate the vitamins needed for growth and development to fight the physiological stress thus compromising their fitness. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Effect of dust aerosol exposure on lung function and lung histopathology in rats].

PubMed

Lei, Fengfeng; Wang, Xuebin; Liu, Hua; Chen, Qizhang; Ma, Hui; Dong, Zhibao; Sang, Yingzhu

2015-08-25

To investigate the effect of dust aerosol exposure on lung function and lung histopathology in rats. According to random number table method, 120 Wistar male rats were divided into untreated control group, treated control group and experimental group, with 40 rats in each group. Experimental group were exposed to the wind tunnel simulation of sandstorm for 5 hours in every day; the untreated control group were put in the standard living environment next to the wind tunnel; the treated control group were exposed to the same wind tunnel simulation of sandstorm for 5 hours in every day, and the speed of wind was the same as the experimental group, but excluding dust. At different time points, the lung function and electron microscopy were performed in all rats. The level of Dynamic Compliance (Cdyn) ((0.227 ± 0.023), (0.198 ± 0.022) ml/cmH₂O, 1 cmH₂O=0.098 kPa) and forced vital capacity (FVC) ((6.24 ± 0.29), (5.59 ± 0.19) ml) were lower in the experimental group at 90 and 120 days, as compared to the untreated control group (Cdyn: (0.266 ± 0.014), (0.265 ± 0.018) ml/cmH2O; FVC: (7.15 ± 0.23), (7.17 ± 0.20) ml) and treated control group (Cdyn: (0.269 ± 0.015), (0.264 ± 0.019) ml/cmH2O; FVC: (7.14 ± 0.19), (7.15 ± 0.21) ml) (all P<0.05). At 120 days, The level of the forced expiratory flow after 50% of the FVC ((12.3 ± 2.2) ml/s) and peak expiratory flow ((25.79 ± 0.42) ml/s) were lower in the experimental group, as compared to the untreated control group ((15.9 ± 2.5), (27.99 ± 0.36) ml/s) and treated control group ((15.8 ± 2.1), (27.90 ± 0.38) ml/s) (all P<0.01). The FVC rate of 0.2 second in the experimental group was higher than that in the untreated control group and treated control group ( (85 ± 5)%, (73 ± 4)%, (73 ± 4)%, all P<0.05). The electron microscopy showed that the lung tissues had no obvious abnormalities at 30, 60, 90 and 120 days in untreated control group and treated control group. But in the experimental group, at 30 days, the endothelial cells of alveolar type I cells were swelled and the number of alveolar type II cells were increased; at 60 days, alveolar type II cells hyperplastic, basement membrane thinned and destructed; at 90 days, the number of alveolar type II cells decreased, Lamellar body evacuation; at 120 days, a lot of collagen fiber was formed in the alveolar septa. The strong sandstorm environmental exposure to a certain period of time can cause the decline of lung function and the damage of lung histopathology in rats. Exposure time was positively correlated with the damage of lung tissue.

The administration of a high refined carbohydrate diet promoted an increase in pulmonary inflammation and oxidative stress in mice exposed to cigarette smoke

PubMed Central

Pena, Karina Braga; Ramos, Camila de Oliveira; Soares, Nícia Pedreira; da Silva, Pamela Félix; Bandeira, Ana Carla Balthar; Costa, Guilherme de Paula; Cangussú, Sílvia Dantas; Talvani, André; Bezerra, Frank Silva

2016-01-01

This study aimed to evaluate the effects of a high refined carbohydrate diet and pulmonary inflammatory response in C57BL/6 mice exposed to cigarette smoke (CS). Twenty-four male mice were divided into four groups: control group (CG), which received a standard diet; cigarette smoke group (CSG), which was exposed to CS; a high refined carbohydrate diet group (RG), which received a high refined carbohydrate diet; and a high refined carbohydrates diet and cigarette smoke group (RCSG), which received a high refined carbohydrate diet and was exposed to CS. The animals were monitored for food intake and body weight gain for 12 weeks. After this period, the CSG and RCSG were exposed to CS for five consecutive days. At the end of the experimental protocol, all animals were euthanized for subsequent analyses. There was an increase of inflammatory cells in the bronchoalveolar lavage fluid (BALF) of CSG compared to CG and RCSG compared to CG, CSG, and RG. In addition, in the BALF, there was an increase of tumor necrosis factor alpha in RCSG compared to CG, CSG, and RG; interferon gamma increase in RCSG compared to the CSG; and increase in interleukin-10 in RCSG compared to CG and RG. Lipid peroxidation increased in RCSG compared to CG, CSG, and RG. Furthermore, the oxidation of proteins increased in CSG compared to CG. The analysis of oxidative stress showed an increase in superoxide dismutase in RCSG compared to CG, CSG, and RG and an increase in the catalase activity in RCSG compared with CG. In addition, there was a decrease in the glutathione reduced/glutathione total ratio of CSG, RG, and RCSG compared to CG. Therefore, the administration of a high refined carbohydrate diet promoted an increase in pulmonary inflammation and oxidative stress in mice exposed to CS. PMID:28008246

Effects of Wi-Fi (2.45 GHz) Exposure on Apoptosis, Sperm Parameters and Testicular Histomorphometry in Rats: A Time Course Study.

PubMed

Shokri, Saeed; Soltani, Aiob; Kazemi, Mahsa; Sardari, Dariush; Mofrad, Farshid Babapoor

2015-01-01

In today's world, 2.45-GHz radio-frequency radiation (RFR) from industrial, scientific, medical, military and domestic applications is the main part of indoor-outdoor electromagnetic field exposure. Long-term effects of 2.45-GHz Wi-Fi radiation on male reproductive system was not known completely. Therefore, this study aimed to investigate the major cause of male infertility during short- and long-term exposure of Wi-Fi radiation. This is an animal experimental study, which was conducted in the Department of Anatomical Sciences, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, IRAN, from June to August 2014. Three-month-old male Wistar rats (n=27) were exposed to the 2.45 GHz radiation in a chamber with two Wi-Fi antennas on opposite walls. Animals were divided into the three following groups: I. control group (n=9) including healthy animals without any exposure to the antenna, II. 1-hour group (n=9) exposed to the 2.45 GHz Wi-Fi radiation for 1 hour per day during two months and III.7-hour group (n=9) exposed to the 2.45 GHz Wi-Fi radiation for 7 hours per day during 2 months. Sperm parameters, caspase-3 concentrations, histomorphometric changes of testis in addition to the apoptotic indexes were evaluated in the exposed and control animals. Both 1-hour and 7-hour groups showed a decrease in sperm parameters in a time dependent pattern. In parallel, the number of apoptosis-positive cells and caspase-3 activity increased in the seminiferous tubules of exposed rats. The seminal vesicle weight reduced significantly in both1-hour or 7-hour groups in comparison to the control group. Regarding to the progressive privilege of 2.45 GHz wireless networks in our environment, we concluded that there should be a major concern regarding the timedependent exposure of whole-body to the higher frequencies of Wi-Fi networks existing in the vicinity of our living places.

Assessing Effects of Prenatal Alcohol Exposure Using Group-wise Sparse Representation of FMRI Data

PubMed Central

Lv, Jinglei; Jiang, Xi; Li, Xiang; Zhu, Dajiang; Zhao, Shijie; Zhang, Tuo; Hu, Xintao; Han, Junwei; Guo, Lei; Li, Zhihao; Coles, Claire; Hu, Xiaoping; Liu, Tianming

2015-01-01

Task-based fMRI activation mapping has been widely used in clinical neuroscience in order to assess different functional activity patterns in conditions such as prenatal alcohol exposure (PAE) affected brains and healthy controls. In this paper, we propose a novel, alternative approach of group-wise sparse representation of the fMRI data of multiple groups of subjects (healthy control, exposed non-dysmorphic PAE and exposed dysmorphic PAE) and assess the systematic functional activity differences among these three populations. Specifically, a common time series signal dictionary is learned from the aggregated fMRI signals of all three groups of subjects, and then the weight coefficient matrices (named statistical coefficient map (SCM)) associated with each common dictionary were statistically assessed for each group separately. Through inter-group comparisons based on the correspondence established by the common dictionary, our experimental results have demonstrated that the group-wise sparse coding strategy and the SCM can effectively reveal a collection of brain networks/regions that were affected by different levels of severity of PAE. PMID:26195294

A new experimental model of cigarette smoke-induced emphysema in Wistar rats*, **

PubMed Central

Kozma, Rodrigo de las Heras; Alves, Edson Marcelino; Barbosa-de-Oliveira, Valter Abraão; Lopes, Fernanda Degobbi Tenorio Quirino dos Santos; Guardia, Renan Cenize; Buzo, Henrique Vivi; de Faria, Carolina Arruda; Yamashita, Camila; Cavazzana, Manzelio; Frei, Fernando; Ribeiro-Paes, Maria José de Oliveira; Ribeiro-Paes, João Tadeu

2014-01-01

OBJECTIVE: To describe a new murine model of cigarette smoke-induced emphysema. METHODS: Twenty-four male Wistar rats were divided into two groups: the cigarette smoke group, comprising 12 rats exposed to smoke from 12 commercial filter cigarettes three times a day (a total of 36 cigarettes per day) every day for 30 weeks; and the control group, comprising 12 rats exposed to room air three times a day every day for 30 weeks. Lung function was assessed by mechanical ventilation, and emphysema was morphometrically assessed by measurement of the mean linear intercept (Lm). RESULTS: The mean weight gain was significantly (approximately ten times) lower in the cigarette smoke group than in the control group. The Lm was 25.0% higher in the cigarette smoke group. There was a trend toward worsening of lung function parameters in the cigarette smoke group. CONCLUSIONS: The new murine model of cigarette smoke-induced emphysema and the methodology employed in the present study are effective and reproducible, representing a promising and economically viable option for use in studies investigating the pathophysiology of and therapeutic approaches to COPD. PMID:24626269

Effects of Historical and Social Variables on Instruction Following

ERIC Educational Resources Information Center

Kroger-Costa, Andreia; Abreu-Rodrigues, Josele

2012-01-01

The present study investigated the effect of the presence of the experimenter on behavioral sensitivity to contingency change. In history training, college students were exposed to differential reinforcement of low rate (DRL) and fixed-ratio (FR) schedules, and in testing, to a fixed-interval (FI) schedule. For the control group, instructions were…

Risk of single and combined exposure of birds to non-steroidal anti-inflammatory drugs and lead.

PubMed

Osickova, Jitka; Skochova, Hana; Ondracek, Karel; Kral, Jiri; Damkova, Veronika; Peckova, Lucie; Pohanka, Miroslav; Vitula, Frantisek; Bandouchova, Hana; Pikula, Jiri

2012-01-01

Pharmaceuticals and heavy metals such as diclofenac and lead, respectively, have been identified as environmental contaminants toxic to birds and posing serious threats to declining populations of raptors worldwide. The aim of the present study was to test the hypothesis that a sublethal combination of non-steroidal anti-inflammatory drugs and lead induces more pronounced effects than single exposures in birds. A total of 40 Japanese quails (Coturnix coturnix japonica) at the age of 2 months and average weight of 180g were on a random basis divided into four experimental groups of 10 specimens (i.e., control, diclofenac, lead, and lead+diclofenac exposures). Six lead shots in the total weight of 1.5 grams were inserted into the crop on day 0 of the experiment, while a total of 5 mg/kg of diclofenac administered intramuscularly were divided into treatments on days 0 and 5. Group responses were compared using haematology and biochemistry after 10 days. There was no mortality in control and both single and combined diclofenac and lead exposure groups, nor did the birds show any clinical signs of intoxication. Univariate analyses of blood parameters yielded a decrease in haematocrit in birds exposed to both substances when compared with the control, a lower haemoglobin level of the lead-exposed group, increased activity of aspartate aminotransferase in the NSAIDs-exposed group, increased activity of alkaline phosphatase in birds exposed to a combination of diclofenac and lead, and a higher phosphorus level in the lead-exposed group. The principal component analysis revealed no multivariate pattern of responses of blood parameters and did not allow separation of exposure groups from controls when the variables and samples were projected onto a two dimensional space. Results of the present study can enhance understanding of combination toxicity of veterinary drugs and heavy metals in birds, i.e. a scenario that has become environmentally relevant in recent decades. Fortunately, individual blood parameter effects prevailed and no joint mortal effects were recognised in Japanese quails exposed to a combination of sublethal doses of diclofenac and lead.

Efficacy of tourniquets exposed to the afghanistan combat environment stored in individual first aid kits versus on the exterior of plate carriers.

PubMed

Weppner, Justin; Lang, Michael; Sunday, Robert; Debiasse, Nicholas

2013-03-01

Between February and May 2010, 1st Battalion, 6th Marines reported a 10% (10/92) breakage rate for tourniquets. One theory suggested was that tourniquets were weakened by exposure to the Afghan environment. Our study was designed to compare three groups of Afghanistan-exposed tourniquets to unexposed tourniquets. The three experimental arms were: (1) Afghan-exposed tourniquets worn on the plate carrier, (2) Afghan-exposed tourniquets carried in the Individual First Aid Kit (IFAK) and wrapped in manufacturer plastic wrapping, and (3) Afghan-exposed tourniquets carried in the IFAK with the manufacturer plastic wrapping removed. The outcome measures of this study were efficacy, breakage, and number of turns required to successfully stop the distal pulse. Tourniquets worn on the plate carrier had an efficacy of 57%, which was significantly lower than the control efficacy rate of 95.2%. When compared to the control arm, there were no significant differences in efficacy between the tourniquets stored in the IFAK with or without manufacturing packaging. No control tourniquets or tourniquets stored in IFAKs broke; however, 46 (12%) of the plate carrier-exposed tourniquets did break. No statistically significant differences were found between the four groups with regard to the median number of turns required to stop the distal pulse. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

Persuader sex differences and peer pressure effects on attitudes toward drug abuse.

PubMed

Stone, C I; Shute, R E

1977-01-01

This experiment was performed to assess the effects of the experimental confederates' sex and contrived group peer pressure on the drug attitudes of male college students. Subjects were exposed to all-male or all-female groups of experimental confederates (ersuaders) who expressed either extremely pro-drug or anti-drug sentiments in a guided group discussion. A drug attitude survey encompassing four drug categories was administered immediately following the discussion. Significant differences were found between subjects in the anti-drug and pro-drug groups. The sex effect data indicated that the male subjects reported more liberal drug attitudes following exposure to female persuaders in both the anti-and pro-drug treatment conditions for the more socially acceptable drugs such as marijuana, hashish, and stimulants. Implications of these findings for possible prevention and intervention strategies and for further research are discussed.

Effect of porous xenographic bone graft with collagen barrier membrane on periodontal regeneration.

PubMed

Yamada, Satoru; Shima, Nobuhiro; Kitamura, Hidekazu; Sugito, Hiroki

2002-08-01

The purpose of this study was to investigate the effect of porous xenographic bone graft (Bio-Oss) with a collagen barrier membrane (Bio-Gide) on formation of new cementum and new bone in experimental intrabony defects of dogs. The intrabony defects were treated by either guided tissue regeneration with the collagen membrane (control group) or the collagen membrane with the porous bone mineral graft (experimental group). After 8 weeks, the animals were sacrificed and the tissues were histologically examined. New cementum with inserting collagen fibers was observed on the exposed surfaces in both groups. The amount of nevv bone was significantly greater in the group using the bone graft with the membrane than in the control group. The use of the collagen barrier membrane in combination with the porous bone graft material may enhance new bone and cementum formation.

Atelocollagen Enhances the Healing of Rotator Cuff Tendon in Rabbit Model.

PubMed

Suh, Dong-Sam; Lee, Jun-Keun; Yoo, Ji-Chul; Woo, Sang-Hun; Kim, Ga-Ram; Kim, Ju-Won; Choi, Nam-Yong; Kim, Yongdeok; Song, Hyun-Seok

2017-07-01

Failure of rotator cuff healing is a common complication despite the rapid development of surgical repair techniques for the torn rotator cuff. To verify the effect of atelocollagen on tendon-to-bone healing in the rabbit supraspinatus tendon compared with conventional cuff repair. Controlled laboratory study. A tear of the supraspinatus tendon was created and repaired in 46 New Zealand White rabbits. They were then randomly allocated into 2 groups (23 rabbits per group; 15 for histological and 8 for biomechanical test). In the experimental group, patch-type atelocollagen was implanted between bone and tendon during repair; in the control group, the torn tendon was repaired without atelocollagen. Each opposite shoulder served as a sham (tendon was exposed only). Histological evaluation was performed at 4, 8, and 12 weeks. Biomechanical tensile strength was tested 12 weeks after surgery. Histological evaluation scores of the experimental group (4.0 ± 1.0) were significantly superior to those of the control group (7.7 ± 2.7) at 12 weeks ( P = .005). The load to failure was significantly higher in the experimental group (51.4 ± 3.9 N) than in the control group (36.4 ± 5.9 N) ( P = .001). Histological and biomechanical studies demonstrated better results in the experimental group using atelocollagen in a rabbit model of the supraspinatus tendon tear. Atelocollagen patch could be used in the cuff repair site to enhance healing.

Chronic consumption of distilled sugarcane spirit induces anxiolytic-like effects in mice.

PubMed

Sena, Maria Clecia P; Nunes, Fabíola C; Salvadori, Mirian G S Stiebbe; Carvalho, Cleyton Charles D; Morais, Liana Clebia S L; Braga, Valdir A

2011-01-01

Chronic ethanol consumption is a major public health problem throughout the world. We investigated the anxiolytic-like effects and the possible ever injury induced by the chronic consumption of ethanol or sugarcane spirit in mice. Adult mice were exposed to a two-bottle free-choice paradigm for 6 weeks. The mice in Group A (n = 16) had access to sugarcane spirit + distilled water, the mice in Group B (n = 15) had access to ethanol + distilled water, and the mice in Group C (control, n = 14) had access to distilled water + distilled water. The ethanol content in the beverages offered to Groups A and B was 2% for the first week, 5% for the second week and 10% for the remaining four weeks. At the end of the experimental period, the mice were evaluated using the elevated-plus maze and the hole-board test to assess their anxiety-related behaviors. We also determined the serum aspartate aminotransferase and alanine aminotransferase levels. In the elevated-plus maze, the time spent in the open arms was increased in the mice exposed to chronic ethanol (32 ± 8 vs. 7 ± 2 s, n = 9) or sugarcane spirit (36 ± 9 vs. 7 ± 2 s, n = 9) compared to the controls. In the hole-board test, the mice exposed to ethanol or sugarcane spirit displayed increases in their head-dipping frequency (16 ± 1 for the control group, 27 ± 2 for the ethanol group, and 31 ± 3 for the sugarcane-spirit group; n = 9 for each group). In addition, the mice exposed to sugarcane spirit displayed an increase in the aspartate aminotransferase / alanine aminotransferase ratio compared to the ethanol group (1.29 ± 0.17 for the control group and 2.67 ± 0.17 for the sugarcane spirit group; n = 8 for each group). The chronic consumption of sugarcane-spirit produces liver injury and anxiolytic-like effects and the possible liver injury in mice.

The Potential Protective Effects of 2-aminoethyl Diphenylborinate against Inner Ear Acoustic Trauma: Experimental Study Using Transmission and Scanning Electron Microscopy.

PubMed

Kaymakçı, Mustafa; Acar, Mustafa; Burukoglu, Dilek; Kutlu, Hatice Mehtap; Shojaolsadati, Paria; Cingi, Cemal; Bayar Muluk, Nuray

2015-04-01

In this prospective experimental study, we investigated the preventive effects of 2-aminoethyl diphenylborinate (2-APB) in rats exposed to acoustic trauma (AT). Light microscopic, transmission electron microscopic (TEM), and scanning electron microscopic (SEM) examinations were performed. Eighteen healthy Wistar albino rats were divided into the following three groups: groups 1 (control), 2 (AT), and 3 (AT+APB). The rats in groups 2 and 3 were exposed to AT; in group 3 rats, 2-APB at 2 mg/kg was also administered, initially transperitoneally, after 10 min. During the light microscopic, TEM, and SEM examinations, the structures of the cochlear hair cells, stereocilia, and Deiter's cells were normal in the control group. In the AT group, the organ of Corti and proximate structures were damaged according to the light microscopic examination. During the TEM examination, intense cellular damage and stereocilia loss were detected, while during the SEM examination, extensive damage and stereocilia loss were observed. Decreased damage with preserved cochlear structure was detected during the light microscopic examination in the AT+APB group than in the AT group. During the TEM and SEM examinations, although stereocilia loss occurred in the AT+APB group, near-normal cell, cilia, and tectorial membrane structures were also observed in the AT+APB group compared with the AT group. 2-APB may have protective effects against AT damage of the cochlea. The main mechanism underlying this effect is the inhibition of the vasoconstriction of the cochlear spiral modiolar artery, thereby improving cochlear blood flow. We conclude that 2-APB may also be effective if used immediately following AT.

The Effectiveness of Empowerment Program on Increasing Self-Esteem, Learned Resourcefulness, and Coping Ways in Women Exposed to Domestic Violence.

PubMed

Bahadir-Yilmaz, Emel; Öz, Fatma

2018-02-01

This study was conducted to assess the effectiveness of empowerment program on increasing self-esteem, learned resourcefulness, and coping ways in women exposed to domestic violence. This experimental study was conducted between October 2012 and June 2014 in the obstetrics and gynaecology departments of the Giresun Maternity Hospital, and at the Family Counseling Center (FCC) in Turkey. Sixty women who agreed to participate in the study were randomly assigned into two groups. Data were collected by the Coopersmith Self-Esteem Inventory (SEI), The Rosenbaum's Learned Resourcefulness Scale (RLRS), and the Ways of Coping Inventory (WCI). The assessment of the women before and after the empowerment program showed that women in the intervention group showed significant improvements in the SEI, RLRS, and WCI scores compared with controls. These results suggest that the empowerment program is an effective practice for increasing the levels of self-esteem, learned resourcefulness, and coping ways of women exposed to domestic violence.

Influence of Landmarks on Spatial Memory in Short-nosed Fruit Bat, Cynopterus sphinx.

PubMed

Zeng, Yu; Zhang, Xin-Wen; Zhu, Guang-Jian; Gong, Yan-Yan; Yang, Jian; Zhang, Li-Biao

2010-04-01

In order to study the relationship between landmarks and spatial memory in short-nosed fruit bat, Cynopterus sphinx (Megachiroptera, Pteropodidae), we simulated a foraging environment in the laboratory. Different landmarks were placed to gauge the spatial memory of C. sphinx. We changed the number of landmarks every day with 0 landmarks again on the fifth day (from 0, 2, 4, 8 to 0). Individuals from the control group were exposed to the identical artificial foraging environment, but without landmarks. The results indicated that there was significant correlation between the time of the first foraging and the experimental days in both groups (Pearson Correlation: experimental group: r=-0.593, P<0.01; control group: r=-0.581, P<0.01). There was no significant correlation between the success rates of foraging and the experimental days in experimental groups (Pearson Correlation: r=0.177, P>0.05), but there was significant correlation between the success rates of foraging and the experimental days in the control groups (Pearson Correlation: r=0.445, P<0.05). There was no significant difference for the first foraging time between experimental and control groups (GLM: F(0.05,1 )=4.703, P>0.05); also, there was no significant difference in success rates of foraging between these two groups (GLM: F(0.05,1 )=0.849, P>0.05). The results of our experiment suggest that spatial memory in C. sphinx was formed gradually and that the placed landmarks appeared to have no discernable effects on the memory of the foraging space.

Virtual reality and the traditional method for phlebotomy training among college of nursing students in Kuwait: implications for nursing education and practice.

PubMed

Vidal, Victoria L; Ohaeri, Beatrice M; John, Pamela; Helen, Delles

2013-01-01

This quasi-experimental study, with a control group and experimental group, compares the effectiveness of virtual reality simulators on developing phlebotomy skills of nursing students with the effectiveness of traditional methods of teaching. Performance of actual phlebotomy on a live client was assessed after training, using a standardized form. Findings showed that students who were exposed to the virtual reality simulator performed better in the following performance metrics: pain factor, hematoma formation, and number of reinsertions. This study confirms that the use of the virtual reality-based system to supplement the traditional method may be the optimal program for training.

Efficacy of three drugs for protecting against gentamicin-induced hair cell and hearing losses

PubMed Central

Bas, E; Van De Water, TR; Gupta, C; Dinh, J; Vu, L; Martínez-Soriano, F; Láinez, JM; Marco, J

2012-01-01

BACKGROUND AND PURPOSE Exposure to an ototoxic level of an aminoglycoside can result in hearing loss. In this we study investigated the otoprotective efficacy of dexamethasone (DXM), melatonin (MLT) and tacrolimus (TCR) in gentamicin (GM)-treated animals and cultures. EXPERIMENTAL APPROACH Wistar rats were divided into controls (treated with saline); exposed to GM only (GM); and three GM-exposed groups treated with either DXM, MLT or TCR. Auditory function and cochlear surface preparations were studied. In vitro studies of oxidative stress, pro-inflammatory cytokine mRNA levels, the MAPK pathway and caspase-3 activation were performed in organ of Corti explants from 3-day-old rats. KEY RESULTS DXM, MLT and TCR decreased levels of reactive oxygen species in GM-exposed explants. The mRNA levels of TNF-α, IL-1β and TNF-receptor type 1 were significantly reduced in GM + DXM and GM + MLT groups. Phospho-p38 MAPK levels decreased in GM + MLT and GM + TCR groups, while JNK phosphorylation was reduced in GM + DXM and GM + MLT groups. Caspase-3 activation decreased in GM + DXM, GM + MLT and GM + TCR groups. These results were consistent with in vivo results. Local treatment of GM-exposed rat cochleae with either DXM, MLT or TCR preserved auditory function and prevented auditory hair cell loss. CONCLUSIONS AND IMPLICATIONS In organ of Corti explants, GM increased oxidative stress and initiated an inflammatory response that led to the activation of MAPKs and apoptosis of hair cells. The three compounds tested demonstrated otoprotective properties that could be beneficial in the treatment of ototoxicity-induced hearing loss. PMID:22320124

The impact of presentation style on the retention of online health information: a randomized-controlled experiment.

PubMed

Frisch, Anne-Linda; Camerini, Luca; Schulz, Peter J

2013-01-01

The Internet plays an increasingly important role in health education, providing laypeople with information about health-related topics that range from disease-specific contexts to general health promotion. Compared to traditional health education, the Internet allows the use of multimedia applications that offer promise to enhance individuals' health knowledge and literacy. This study aims at testing the effect of multimedia presentation of health information on learning. Relying on an experimental design, it investigates how retention of information differs for text-only presentation, image-only presentation, and multimedia (text and image) presentation of online health information. Two hundred and forty students were randomly assigned to four groups each exposed to a different website version. Three groups were exposed to the same information using text only, image only, or text and image presentation. A fourth group received unrelated information (control group). Retention was assessed by the means of a recognition test. To examine a possible interaction between website version and recognition test, half of the students received a recognition test in text form and half of them received a recognition test in imagery form. In line with assumptions from Dual Coding Theory, students exposed to the multimedia (text and image) presentation recognized significantly more information than students exposed to the text-only presentation. This did not hold for students exposed to the image-only presentation. The impact of presentation style on retention scores was moderated by the way retention was assessed for image-only presentation, but not for text-only or multimedia presentation. Possible explanations and implications for the design of online health education interventions are discussed.

No adverse effects detected for simultaneous whole-body exposure to multiple-frequency radiofrequency electromagnetic fields for rats in the intrauterine and pre- and post-weaning periods

PubMed Central

Shirai, Tomoyuki; Wang, Jianqing; Kawabe, Mayumi; Wake, Kanako; Watanabe, So-ichi; Takahashi, Satoru; Fujiwara, Osamu

2017-01-01

In everyday life, people are exposed to radiofrequency (RF) electromagnetic fields (EMFs) with multiple frequencies. To evaluate the possible adverse effects of multifrequency RF EMFs, we performed an experiment in which pregnant rats and their delivered offspring were simultaneously exposed to eight different communication signal EMFs (two of 800 MHz band, two of 2 GHz band, one of 2.4 GHz band, two of 2.5 GHz band and one of 5.2 GHz band). Thirty six pregnant Sprague-Dawley (SD) 10-week-old rats were divided into three groups of 12 rats: one control (sham exposure) group and two experimental (low- and high-level RF EMF exposure) groups. The whole body of the mother rats was exposed to the RF EMFs for 20 h per day from Gestational Day 7 to weaning, and F1 offspring rats (46–48 F1 pups per group) were then exposed up to 6 weeks of age also for 20 h per day. The parameters evaluated included the growth, gestational condition and organ weights of the dams; the survival rates, development, growth, physical and functional development, memory function, and reproductive ability of the F1 offspring; and the embryotoxicity and teratogenicity in the F2 rats. No abnormal findings were observed in the dams or F1 offspring exposed to the RF EMFs or to the F2 offspring for any of the parameters evaluated. Thus, under the conditions of the present experiment, simultaneous whole-body exposure to eight different communication signal EMFs at frequencies between 800 MHz and 5.2 GHz did not show any adverse effects on pregnancy or on the development of rats. PMID:27694283

The influence of static magnetic field (50 mT) on development and motor behaviour of Tenebrio (Insecta, Coleoptera).

PubMed

Todorović, Dajana; Marković, Tamara; Prolić, Zlatko; Mihajlović, Spomenko; Rauš, Snežana; Nikolić, Ljiljana; Janać, Branka

2013-01-01

There is considerable concern about potential effects associated with exposure to magnetic fields on organisms. Therefore, duration of pupa-adult development and motor behaviour of adults were analyzed in Tenebrio obscursus and T. molitor after exposure to static magnetic field (50 mT). The experimental groups were: Control (kept 5 m from the magnets), groups which pupae and adults were placed closer to the North pole, or closer to the South pole of magnetic dipole. The pupae were exposed to the magnetic field until the moment of adult eclosion. The pupa-adult development dynamics were recorded daily. Subsequently, behaviour (distance travelled, average speed and immobility) of adults exposed to the magnetic field was monitored in a circular open field arena. Static magnetic field did not affect pupa-adult developmental dynamic of examined Tenebrio species. Exposure to magnetic field did not significantly change motor behaviour of T. obscurus adults. The changes in the motor behaviour of T. molitor induced by static magnetic field were opposite in two experimental groups developed closer to the North pole or closer to the South pole of magnetic dipole. Static magnetic field (50 mT) did not affect on pupa-adult development dynamic of two examined Tenebrio species, but modulated their motor behaviour.

[Effect of extremely low frequency magnetic field on glutathione in rat muscles].

PubMed

Ciejka, Elzbieta; Jakubowska, Ewa; Zelechowska, Paulina; Huk-Kolega, Halina; Kowalczyk, Agata; Goraca, Anna

2014-01-01

Free radicals (FR) are atoms, molecules or their fragments. Their excess leads to the development of oxidizing stress, the cause of many neoplastic, neurodegenerative and inflammatory diseases, and aging of the organism. Industrial pollution, tobacco smoke, ionizing radiation, ultrasound and magnetic field are the major FR exogenous sources. The low frequency magnetic field is still more commonly applied in the physical therapy. The aim of the presented study was to evaluate the effect of extremely low frequency magnetic field used in the magnetotherapy on the level of total glutathione, oxidized and reduced, and the redox state of the skeletal muscle cells, depending on the duration of exposure to magnetic field. The male rats, weight of 280-300 g, were randomly devided into 3 experimental groups: controls (group I) and treatment groups exposed to extremely low frequency magnetic field (ELF-MF) (group II exposed to 40 Hz, 7 mT for 0.5 h/day for 14 days and group III exposed to 40 Hz, 7 mT for 1 h/day for 14 days). Control rats were kept in a separate room not exposed to extremely low frequency magnetic field. Immediately after the last exposure, part of muscles was taken under pentobarbital anesthesia. Total glutathione, oxidized and reduced, and the redox state in the muscle tissue of animals were determined after exposure to magnetic fields. Exposure to low magnetic field: 40 Hz, 7 mT for 30 min/day and 60 min/day for 2 weeks significantly increased the total glutathione levels in the skeletal muscle compared to the control group (p < 0.001). Exposure to magnetic fields used in the magnetic therapy plays an important role in the development of adaptive mechanisms responsible for maintaining the oxidation-reduction balance in the body and depends on exposure duration.

Increased alveolar plasminogen activator in early asbestosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cantin, A.; Allard, C.; Begin, R.

1989-03-01

Alveolar macrophage-derived plasminogen activator (PA) activity is decreased in some chronic interstitial lung diseases such as idiopathic pulmonary fibrosis and sarcoidosis but increased in experimental models of acute alveolitis. Although asbestos fibers can stimulate alveolar macrophages (AM) to release PA in vitro, the effect of chronic asbestos exposure of the lower respiratory tract on lung PA activity remains unknown. The present study was designed to evaluate PA activity of alveolar macrophages and bronchoalveolar lavage (BAL) fluid in asbestos-exposed sheep and asbestos workers. Forty-three sheep were exposed to either 100 mg UICC chrysotile B asbestos in 100 ml phosphate-buffered saline (PBS)more » or to 100 ml PBS by tracheal infusion every 2 wk for 18 months. At Month 18, chest roentgenograms were analyzed and alveolar macrophage and extracellular fluid PA activity were measured in samples obtained by BAL. Alveolar macrophage PA activity was increased in the asbestos-exposed sheep compared to control sheep (87.2 +/- 17.3 versus 41.1 +/- 7.2 U/10(5) AM-24 h, p less than 0.05) as was the BAL fluid PA activity (674.9 +/- 168.4 versus 81.3 +/- 19.7 U/mg alb-24 h, p less than 0.01). Among the asbestos-exposed sheep, 10 had normal chest roentgenograms (Group SA) and 15 had irregular interstitial opacities (Group SB). Strikingly, whereas Group SA did not differ from the control group in BAL cellularity or PA activity, Group SB had marked increases in alveolar macrophages (p less than 0.005), AM PA activity (p less than 0.02), and BAL PA activity (p less than 0.001) compared to the control group.« less

Influence of undergraduate nursing student teaching methods on learning standard precautions and transmission-based precautions: Experimental research.

PubMed

Kappes Ramirez, Maria Soledad

2018-02-01

An experimental study was performed with undergraduate nursing students in order to determine, between two methodologies, which is the best for learning standard precautions and precautions based on disease transmission mechanisms. Students in the sample are stratified by performance, with the experimental group (49 students) being exposed to self-instruction and clinical simulation on the topic of standard precautions and special precautions according to disease transmission mechanisms. Conventional classes on the same topics were provided to the control group (49 students). The experimental group showed the best performance in the multiple-choice post-test of knowledge (p=0.002) and in the assessment of essay questions (p=0.043), as well as in the evaluation of a simulated scenario, in relation to the control group. This study demonstrates that it is possible to transfer some teaching subjects on the prevention of Healthcare Associated Infections (HAIs) to self-learning by means of virtual teaching strategies with good results. This allows greater efficiency in the allocation of teachers to clinical simulation or learning situations in the laboratory, where students can apply what they have learned in the self-instruction module. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Randomized Trial of a Web-based Intervention to Improve Migraine Self-Management and Coping

PubMed Central

Bromberg, Jonas; Wood, Mollie E.; Black, Ryan A.; Surette, Daniel A.; Zacharoff, Kevin L.; Chiauzzi, Emil J.

2011-01-01

Objective Test the clinical efficacy of a web-based intervention designed to increase patient self-efficacy to perform headache self-management activities and symptom management strategies; and reduce migraine-related psychological distress. Background In spite of their demonstrated efficacy, behavioral interventions are used infrequently as an adjunct in medical treatment of migraine. Little clinical attention is paid to the behavioral factors that can help manage migraine more effectively, improve the quality of care, and improve quality of life. Access to evidenced-based, tailored, behavioral treatment is limited for many people with migraine. Design The study is a parallel group design with two conditions, (1) an experimental group exposed to the web intervention, and (2) a no-treatment control group that was not exposed to the intervention. Assessments for both groups were conducted at baseline (T1), 1-month (T2), 3-months (T3), and 6-months (T4). Results Compared to controls, participants in the experimental group reported significantly: increased headache self-efficacy, increased use of relaxation, increased use of social support, decreased pain catastrophizing, decreased depression, and decreased stress. The hypothesis that the intervention would reduce pain could not be tested. Conclusions Demonstrated increases in self-efficacy to perform headache self-management, increased use of positive symptom management strategies, and reported decreased migraine-related depression and stress, suggest that the intervention may be a useful behavioral adjunct to a comprehensive medical approach to managing migraine. PMID:22413151

A Cognitive Strategy Instruction to Improve Math Calculation for Children with ADHD and LD: A Randomized Controlled Study

ERIC Educational Resources Information Center

Iseman, Jackie S.; Naglieri, Jack A.

2011-01-01

The authors examined the effectiveness of cognitive strategy instruction based on PASS (Planning, Attention, Simultaneous, Successive) given by special education teachers to students with ADHD randomly assigned by classroom. Students in the experimental group were exposed to a brief cognitive strategy instruction for 10 days, which was designed to…

The Effects of Using WebQuests on Reading Comprehension Performance of Saudi EFL Students

ERIC Educational Resources Information Center

Alshumaimeri, Yousif A.; Almasri, Meshail M.

2012-01-01

This paper is a report on the effects of using WebQuest on Saudi male EFL students reading comprehension performance. WebQuests expose students to several online resources and require them to gather information about a specific topic. The experimental group received traditional teaching plus WebQuests as supplementary activities. The control group…

Using Popular Culture to Teach the Community College Business Curriculum: A Comparative Study

ERIC Educational Resources Information Center

Passero, Thomas

2011-01-01

This study addressed a need for comprehensive quantitative empirical studies to determine the effectiveness of using popular culture media as a teaching technique. A quasi-experimental design was implemented to examine whether a group of community college students taking a first-semester introduction to business course who were exposed to a…

Fostering Ethnic and Religious Harmony through Classroom Language Experiences

ERIC Educational Resources Information Center

Obiekezie, Eucharia Obiageli; Timothy, Alexander Essien

2015-01-01

This paper explores ways the classroom environment can fertilise ethnic and religious tolerance in students. In a pre/post test design, 76 students at a university secondary school in the Niger Delta region of Nigeria were randomly selected to respond to a twenty-item survey. Afterwards, the experimental group was exposed to a critical thinking…

Use of an ESP Cover Story Facilitates Reinforcement without Awareness

ERIC Educational Resources Information Center

Bizo, Lewis A.; Sweeney, Nicola

2005-01-01

Participants were exposed to 3 conditions in a between-groups design. Participants were told the experiment was about extrasensory perception and were asked to select the word from a pair of words that they thought the experimenter was thinking about. In 1 condition selections of the word with a double letter were reinforced with positive verbal…

Experimental Transmission of Karshi (Mammalian Tick-Borne Flavivirus Group) Virus by Ornithodoros Ticks >2,900 Days after Initial Virus Exposure Supports the Role of Soft Ticks as a Long-Term Maintenance Mechanism for Certain Flaviviruses.

PubMed

Turell, Michael J

2015-01-01

Members of the mammalian tick-borne flavivirus group, including tick-borne encephalitis virus, are responsible for at least 10,000 clinical cases of tick-borne encephalitis each year. To attempt to explain the long-term maintenance of members of this group, we followed Ornithodoros parkeri, O. sonrai, and O. tartakovskyi for >2,900 days after they had been exposed to Karshi virus, a member of the mammalian tick-borne flavivirus group. Ticks were exposed to Karshi virus either by allowing them to feed on viremic suckling mice or by intracoelomic inoculation. The ticks were then allowed to feed individually on suckling mice after various periods of extrinsic incubation to determine their ability to transmit virus by bite and to determine how long the ticks would remain infectious. The ticks remained efficient vectors of Karshi virus, even when tested >2,900 d after their initial exposure to virus, including those ticks exposed to Karshi virus either orally or by inoculation. Ornithodoros spp. ticks were able to transmit Karshi virus for >2,900 days (nearly 8 years) after a single exposure to a viremic mouse. Therefore, these ticks may serve as a long-term maintenance mechanism for Karshi virus and potentially other members of the mammalian tick-borne flavivirus group.

Antenatal vitamin A administration attenuates lung hypoplasia by interfering with early instead of late determinants of lung underdevelopment in congenital diaphragmatic hernia.

PubMed

Baptista, Maria J; Melo-Rocha, Gustavo; Pedrosa, Carla; Gonzaga, Sílvia; Teles, Antónia; Estevão-Costa, José; Areias, José C; Flake, Alan W; Leite-Moreira, Adelino F; Correia-Pinto, Jorge

2005-04-01

Early and late lung underdevelopment in congenital diaphragmatic hernia (CDH) is likely caused by nonmechanical (directly mediated by nitrofen) and mechanical (mediated by thoracic herniation) factors, respectively. The authors investigated if vitamin A enhances lung growth because of effects on both early and late determinants of lung hypoplasia. Twenty-seven pregnant Wistar rats were exposed on embryonic day (E)9.5 to 100 mg of nitrofen or just olive oil. From nitrofen-exposed pregnant rats, 12 were treated at day 9.5 or 18.5 with 15,000 IU of vitamin A. Lungs were harvested at E18, E20, and E22, weighed, and analyzed for DNA and protein contents. Left and/or right lung hypoplasia was estimated by assessment of the ratios of lung to body weight and left to right lung weight. Fetuses were assigned to 5 experimental groups: baseline (exposed neither to nitrofen nor vitamin A), nitrofen (exposed to nitrofen without CDH), CDH (exposed to nitrofen with CDH), nitr+vitA (exposed to nitrofen without CDH and treated with vitamin A), and CDH+vitA (exposed to nitrofen with CDH and treated with vitamin A). Incidence of hernia was significantly reduced in fetuses treated with vitamin A. When vitamin A was administered at E9.5, the authors observed similar effect on lung hypoplasia measured through ratio of lung to body weight at E18 in the nitrofen and CDH groups (nitrofen 1.92% +/- 0.05%, CDH 1.92% +/- 0.04%), whereas lung hypoplasia was attenuated relative to baseline (2.45% +/- 0.05%) in 5% and 4% in nitrofen (nitr+vitA 2.05% +/- 0.03%) and CDH (CDH+vitA 2.08% +/- 0.04%) groups, respectively. At E20, lung hypoplasia was increased in CDH compared with nitrofen groups (nitrofen 2.52% +/- 0.1%, CDH 2.39% +/- 0.05%), whereas vitamin A attenuated lung hypoplasia, in relation to baseline (3.20% +/- 0.07%), 14% in both nitrofen-exposed groups (nitr+vitA 2.96% +/- 0.03%, CDH+vitA 2.83% +/- 0.03%). At E22, lung hypoplasia was significantly higher in CDH group than nitrofen group (nitrofen 2.13% +/- 0.06%, CDH 1.48% +/- 0.03%), whereas lung hypoplasia was attenuated in 9% of both nitrofen-exposed groups (nitr+vitA 2.35% +/- 0.06%, CDH+vitA 1.69% +/- 0.05%) in relation to baseline group (2.38% +/- 0.04%). Administration of vitamin A at E18.5 produced no significant effects on lung growth. The authors conclude from these results that antenatal administration of vitamin A attenuates lung hypoplasia in CDH by interfering with early determinants of lung underdevelopment. This finding may have clinical implications because prenatal diagnosis of human CDH commonly occurs after 16 weeks' gestation when late determinants of lung hypoplasia likely predominate.

Hypnosis, suggestions, and altered states of consciousness: experimental evaluation of the new cognitive-behavioral theory and the traditional trance-state theory of "hypnosis".

PubMed

Barber, T X; Wilson, S C

1977-10-07

Sixty-six subjects were tested on a new scale for evaluating "hypnotic-like" experiences (The Creative Imagination Scale), which includes ten standardized test-suggestions (e.g. suggestions for arm heaviness, finger anesthesia, time distortion, and age regression). The subjects were randomly assigned to one of three treatment groups (Think-With Instructions, trance induction, and Control), with 22 subjects to each group. The new Cognitive-Behavioral Theory predicted that subjects exposed to preliminary instructions designed to demonstrate how to think and imagine along with the suggested themes (Think-With Instructions) would be more responsive to test-suggestions for anesthesia, time distortion, age regression, and so on, than subjects exposed to a trance-induction procedure. On the other hand, the traditional Trance State Theory predicted that a trance induction would be more effective than Think-With Instructions in enhancing responses to such suggestions. Subjects exposed to the Think-With Instructions obtained significantly higher scores on the test-suggestions than those exposed either to the traditional trance-induction procedure or to the control treatment. Scores of subjects who received the trance-induction procedure were not significantly different from those of the subjects who received the control treatment. The results thus supported the new Cognitive-Behavioral Theory and contradicted the traditional Trance State Theory of hypnosis. Two recent experiments, by De Stefano and by Katz, confirmed the above experimental results and offered further support for the Cognitive-Behavioral Theory. In both recent experiments, subjects randomly assigned to a "Think-With Instructions" treatment were more responsive to test-suggestions than those randomly assigned to a traditional trance-induction treatment.

Effect of fluoride and low versus high levels of dietary calcium on mRNA expression of osteoprotegerin and osteoprotegerin ligand in the bone of rats.

PubMed

Yu, Jun; Gao, Yanhui; Sun, Dianjun

2013-06-01

The ratio of osteoprotegerin ligand (OPGL) to osteoprotegerin (OPG) determines the delicate balance between bone resorption and synthesis. The main objective of the present study is to investigate the possible role of OPGL and OPG in the bone metabolism of rats exposed to fluoride and the protective or aggravating effect of calcium (Ca). In a 6-month study, 270 weanling male Sprague-Dawley rats weighing between 70 and 90 g were divided randomly into six groups of 45 rats in each group. Three groups (groups I, III, and V)served as controls and drank deionized water and were fed purified rodent diets containing either 1,000 mg Ca/kg (low Ca), 5,000 mg Ca/kg (normal Ca), or 20,000 mg Ca/kg (high Ca). The three experimental groups (groups II, IV, and VI) were given the same diets but they drank water containing 100 mg F ion/L (from NaF). Every 2 months 15 rats were randomly selected from each group and sacrificed for the study. The ratio of OPGL mRNA to OPG mRNA was significantly increased by the sixth month in the distal femur joints of the F-exposed rats. Serum tartrate-resistant acid phosphatase activity and serum calcitonin activity in the F-exposed groups was increased, although changes were not apparent in the serum alkaline phosphatase or Gla-containing proteins, especially in the low calcium and high calcium diet F-exposed groups. The results indicated that OPG and OPGL may play important roles in skeletal fluorosis, and that fluoride may enhance osteoclast formation and induce osteoclastic bone destruction. A high Ca diet did not play a protective role, but rather may aggravate the damage of fluoride.

Plasma proteins in the acquired denture pellicle enhance substrate surface free energy and Candida albicans phospholipase and proteinase activities.

PubMed

Custodio, William; Silva, Wander J; Paes Leme, Adriana F; Cury, Jaime A; Del Bel Cury, Altair A

2015-11-01

The objective of the present study was to determine if blood plasma proteins could change the proteome of the acquired denture pellicle by label-free quantitative proteomics. As pellicle proteome modulates the interaction between substrates and Candida cells, we investigated its effect on the surface free energy (SFE) of the coated resin and on Candida albicans phospholipase and aspartyl proteinase activities. Poly(methylmethacrylate) discs were exposed to saliva (control) or saliva enriched with blood plasma (experimental group). The pellicle proteome was analyzed by mass spectrometry coupled with liquid chromatography. SFE was determined by acid-base technique. After biofilm formation, phospholipase and proteinase activities were determined accordingly to classic plate methods. Data were analyzed by two-way anova and Tukey test (P < 0.05). α-Amylase, cystatins, mucins, and host-immune system proteins were the main proteins identified in the control group. Fibrinogen and albumin were observed only in the experimental group. Coated discs of the experimental group presented an increased SFE (P < 0.05). For both enzymes tested, the experimental group showed higher proteolytic activity (P < 0.001). Blood plasma changes the proteome of the acquired denture pellicle, increasing surface free energy and the activity of Candida albicans phospholipase and aspartyl proteinase. © 2014 Wiley Publishing Asia Pty Ltd.

Changes of glycoconjugate expression in nasal respiratory mucosa of rats exposed to welding fumes.

PubMed

Jeong, Gil Nam; Jo, Un Bock; Yu, Il Je

2007-09-01

To investigate the effects of welding fumes on the glycoconjugates in nasal respiratory mucosa, male Sprague-Dawley rats were exposed to manual metal arc stainless steel (MMA-SS) welding fumes at a concentration of 56-76 mg/m(3) total suspended particulate for 2 h/day in an inhalation chamber for 90 days. During the exposure period, the experimental animals were sacrificed after 2 h and 15, 30, 60, and 90 days of exposure; then sections were examined using lectin histochemistry. Some remarkable changes, such as destroyed cilia, desquamation and mucification of epithelial cells, and destruction of nasal septal glands, were seen in the welding fume-exposed groups. Specific changes in the lectin binding patterns were also observed in the welding fume-exposed rats. The Ricinus communis agglutinin-I (RCA-I) staining of the cilia and columnar cells increased slightly when compared with the unexposed rats. The RCA-I and Ulex europaeus agglutinin-I (UEA-I) staining of the goblet cells also increased as the exposure continued. The mucigenous epithelial cells reacted with Bandeiraea simplicifolia lectin-I (BSL-I), RCA-I, and succinylated wheat germ agglutinin A (sWGA) after 15 days of exposure, which was not visible in the control group. The dorsal septal glands exhibited an affinity with peanut agglutinin (PNA), BSL-I, and RCA-I, which was also not visible in the control group. The affinity for Dolichos biflorus agglutinin (DBA), soybean agglutinin (SBA), PNA, sWGA, BSL-I, and UEA-I in the ventral septal glands of the welding fume-exposed groups tended to increase, whereas the concanavalin A (Con A) reactivity in the dorsal septal glands decreased slightly. In conclusion, it was assumed that the changes in the glycoconjugate residues in the nasal respiratory mucosa of the welding fume-exposed rats represented important components of defense mechanisms against the toxicants in the welding fumes.

The Metabolic Effects of Consumption of Yellow Cassava (Manihot esculenta Crantz) on Some Biochemical Parameters in Experimental Rats.

PubMed

Udeme, Nelson; Okafor, Polycarp; Eleazu, Chinedum

2015-01-01

The metabolism of yellow cassava (variety TMS 01/1368) was investigated in male albino rats fed a diet containing yellow cassava for 7 to 28 days. There were significant increases (P < 0.05) in total and free cyanide and thiocyanate in the sera and urine samples of the experimental rats compared with the control, significant increases (P < 0.05) in serum glucose, alanine aminotransaminase, aspartate aminotransaminase, and alkaline phosphatase levels of the experimental rats compared with the control, significant decreases (P < 0.05) in serum albumin of the experimental rats compared with the control, but no significant differences (P > 0.05) in the serum total proteins of the experimental rats compared with the control. The experimental rats treated for 7, 14, 21, or 28 days exhibited body weight decreases of 5.11%, 11.10%, 19.16%, and 24.18%, respectively, whereas the control group showed 9.17% gain in body weight. Total and free cyanide concentrations were detected in the liver, kidney, and heart of most of the rats in both the experimental and control groups, except for free cyanide in the control group that was not detected. Metabolism of the yellow cassava variety in experimental rats was capable of exposing the animals to cyanide, underscoring the need for its proper processing before consumption by humans. © The Author(s) 2015.

[Influence of extremely low frequency magnetic field on total protein and -sh groups concentrations in liver homogenates].

PubMed

Ciejka, Elżbieta; Kowalczyk, Agata; Gorąca, Anna

2014-01-01

Free radicals are atoms, molecules or their fragments, whose excess leads to the development of oxidative stress, the cause of many neoplastic, neurodegenerative and inflammatory diseases, as well as aging of organisms. Industrial pollution, tobacco smoke, ionizing radiation, ultrasound and magnetic fields are the major exogenous sources of free radicals. The low frequency mag- netic field is commonly applied in physiotherapy. The aim of the present study was to evaluate the effect of extremely low frequency magnetic field (1L.F-MF) on the concentration ofsullhydryl groups (-SH) and proteins in liver tissues of experimental animals de- pending on the time of exposure to the field. Twenty one Sprague-D)awley male rats, aged 3-4 months were randomly divided into 3 experimental groups (each containing 7 animals): controls (group I), the rats exposed to IEI.F-MF of 40 Hz, 7 mT (this kind of the ELF-MF is mostly used in magnetotherapy), 30 min/day for 2 weeks (group II) and the rats exposed to 40 Hz, 7 mT for 60 min/day for 2 weeks (group III). The concentrations of proteins and sulfhydryl groups in the liver tissues were determined after exposure to magnetic fields. Exposure to low magnetic field: 40 Hz, 7 mT for 30 min/day and 60 min/day for 2 weeks caused a significant increase in the concentration of-SH groups and total protein levels in the liver tissues. The study results suggest that exposure to magnetic fields leads to the development of adaptive mechanisms to maintain the balance in the body oxidation-reduction and in the case of the studied parameters does not depend on the time of exposure.

Cost-effectiveness of an experimental caries-control regimen in a 3.4-yr randomized clinical trial among 11-12-yr-old Finnish schoolchildren.

PubMed

Hietasalo, Pauliina; Seppä, Liisa; Lahti, Satu; Niinimaa, Ahti; Kallio, Jouko; Aronen, Pasi; Sintonen, Harri; Hausen, Hannu

2009-12-01

The aim of this study was to assess the cost-effectiveness of an experimental caries-control regimen in a randomized clinical trial (RCT) conducted in Pori, Finland, in 2001-2005. Children (n = 497) who were 11-12 yr of age and had at least one active initial caries lesion at baseline were studied. The children in the experimental group (n = 250) were offered an individually designed patient-centered regimen for caries control. The children in the control group (n = 247) received standard dental care. Furthermore, the whole population was exposed to continuous community-level oral health promotion. Individual costs of treatment procedures and outcomes (DMFS increment score) for the follow-up period of 3.4 yr were calculated for each child in both groups. The incremental cost-effectiveness ratio was euro 34.07 per averted DMF surface. The experimental regimen was more effective, and also more costly. However, the total costs decreased year after year, and for the last 2 yr the experimental regimen was less expensive than the standard dental care. The experimental regimen would probably have been more cost-effective than standard dental care if the follow-up period had been longer, the regimen less comprehensive, and/or if dental nurses had conducted the preventive procedures.

Can't Count or Won't Count? Embedding Quantitative Methods in Substantive Sociology Curricula: A Quasi-Experiment.

PubMed

Williams, Malcolm; Sloan, Luke; Cheung, Sin Yi; Sutton, Carole; Stevens, Sebastian; Runham, Libby

2016-06-01

This paper reports on a quasi-experiment in which quantitative methods (QM) are embedded within a substantive sociology module. Through measuring student attitudes before and after the intervention alongside control group comparisons, we illustrate the impact that embedding has on the student experience. Our findings are complex and even contradictory. Whilst the experimental group were less likely to be distrustful of statistics and appreciate how QM inform social research, they were also less confident about their statistical abilities, suggesting that through 'doing' quantitative sociology the experimental group are exposed to the intricacies of method and their optimism about their own abilities is challenged. We conclude that embedding QM in a single substantive module is not a 'magic bullet' and that a wider programme of content and assessment diversification across the curriculum is preferential.

Evidence for contact calls in fish: conspecific vocalisations and ambient soundscape influence group cohesion in a nocturnal species.

PubMed

van Oosterom, L; Montgomery, J C; Jeffs, A G; Radford, C A

2016-01-11

Soundscapes provide a new tool for the study of fish communities. Bigeyes (Pempheris adspersa) are nocturnal planktivorous reef fish, feed in loose shoals and are soniferous. These vocalisations have been suggested to be contact calls to maintain group cohesion, however direct evidence for this is absent, despite the fact that contact calls are well documented for many other vertebrates, including marine mammals. For fish, direct evidence for group cohesion signals is restricted to the use of visual and hydrodynamic cues. In support of adding vocalisation as a contributing cue, our laboratory experiments show that bigeyes significantly increased group cohesion when exposed to recordings of ambient reef sound at higher sound levels while also decreasing vocalisations. These patterns of behaviour are consistent with acoustic masking. When exposed to playback of conspecific vocalisations, the group cohesion and vocalisation rates of bigeyes both significantly increased. These results provide the first direct experimental support for the hypotheses that vocalisations are used as contact calls to maintain group cohesion in fishes, making fish the evolutionarily oldest vertebrate group in which this phenomenon has been observed, and adding a new dimension to the interpretation of nocturnal reef soundscapes.

Evidence for contact calls in fish: conspecific vocalisations and ambient soundscape influence group cohesion in a nocturnal species

NASA Astrophysics Data System (ADS)

van Oosterom, L.; Montgomery, J. C.; Jeffs, A. G.; Radford, C. A.

2016-01-01

Soundscapes provide a new tool for the study of fish communities. Bigeyes (Pempheris adspersa) are nocturnal planktivorous reef fish, feed in loose shoals and are soniferous. These vocalisations have been suggested to be contact calls to maintain group cohesion, however direct evidence for this is absent, despite the fact that contact calls are well documented for many other vertebrates, including marine mammals. For fish, direct evidence for group cohesion signals is restricted to the use of visual and hydrodynamic cues. In support of adding vocalisation as a contributing cue, our laboratory experiments show that bigeyes significantly increased group cohesion when exposed to recordings of ambient reef sound at higher sound levels while also decreasing vocalisations. These patterns of behaviour are consistent with acoustic masking. When exposed to playback of conspecific vocalisations, the group cohesion and vocalisation rates of bigeyes both significantly increased. These results provide the first direct experimental support for the hypotheses that vocalisations are used as contact calls to maintain group cohesion in fishes, making fish the evolutionarily oldest vertebrate group in which this phenomenon has been observed, and adding a new dimension to the interpretation of nocturnal reef soundscapes.

Evidence for contact calls in fish: conspecific vocalisations and ambient soundscape influence group cohesion in a nocturnal species

PubMed Central

van Oosterom, L.; Montgomery, J. C.; Jeffs, A. G.; Radford, C. A.

2016-01-01

Soundscapes provide a new tool for the study of fish communities. Bigeyes (Pempheris adspersa) are nocturnal planktivorous reef fish, feed in loose shoals and are soniferous. These vocalisations have been suggested to be contact calls to maintain group cohesion, however direct evidence for this is absent, despite the fact that contact calls are well documented for many other vertebrates, including marine mammals. For fish, direct evidence for group cohesion signals is restricted to the use of visual and hydrodynamic cues. In support of adding vocalisation as a contributing cue, our laboratory experiments show that bigeyes significantly increased group cohesion when exposed to recordings of ambient reef sound at higher sound levels while also decreasing vocalisations. These patterns of behaviour are consistent with acoustic masking. When exposed to playback of conspecific vocalisations, the group cohesion and vocalisation rates of bigeyes both significantly increased. These results provide the first direct experimental support for the hypotheses that vocalisations are used as contact calls to maintain group cohesion in fishes, making fish the evolutionarily oldest vertebrate group in which this phenomenon has been observed, and adding a new dimension to the interpretation of nocturnal reef soundscapes. PMID:26750559

Medical experimentation concerning chemical and biological weapons for mass destruction.

PubMed

Deutsch, Erwin

2003-04-01

This article is the text of a speech originally presented at the Second World Conference on Medical Ethics at Gijon, Spain, on 2 October 2002 under the title "Medical Experimentation Concerning Chemical and Biological Weapons for Mass Destruction: Clinical Design for New Smallpox Vaccines: Ethical and Legal Aspects." Experimentation on vaccines such as smallpox is subject to the usual ethical rules such as the need for informed consent. However, the participants will not often be at risk of catching the disease but expose themselves by taking part in the experimentation. Professor Deutsch explores the implications of this, including the position of vulnerable groups such as children, those with mental handicaps, and those acting under orders such as the miliary, the policy and fire officers.

Knowledge-based grouping of modeled HLA peptide complexes.

PubMed

Kangueane, P; Sakharkar, M K; Lim, K S; Hao, H; Lin, K; Chee, R E; Kolatkar, P R

2000-05-01

Human leukocyte antigens are the most polymorphic of human genes and multiple sequence alignment shows that such polymorphisms are clustered in the functional peptide binding domains. Because of such polymorphism among the peptide binding residues, the prediction of peptides that bind to specific HLA molecules is very difficult. In recent years two different types of computer based prediction methods have been developed and both the methods have their own advantages and disadvantages. The nonavailability of allele specific binding data restricts the use of knowledge-based prediction methods for a wide range of HLA alleles. Alternatively, the modeling scheme appears to be a promising predictive tool for the selection of peptides that bind to specific HLA molecules. The scoring of the modeled HLA-peptide complexes is a major concern. The use of knowledge based rules (van der Waals clashes and solvent exposed hydrophobic residues) to distinguish binders from nonbinders is applied in the present study. The rules based on (1) number of observed atomic clashes between the modeled peptide and the HLA structure, and (2) number of solvent exposed hydrophobic residues on the modeled peptide effectively discriminate experimentally known binders from poor/nonbinders. Solved crystal complexes show no vdW Clash (vdWC) in 95% cases and no solvent exposed hydrophobic peptide residues (SEHPR) were seen in 86% cases. In our attempt to compare experimental binding data with the predicted scores by this scoring scheme, 77% of the peptides are correctly grouped as good binders with a sensitivity of 71%.

Magnetic resonance imaging used for the evaluation of water presence in wood plastic composite boards exposed to exterior conditions

Treesearch

Marek Gnatowski; Rebecca Ibach; Mathew Leung; Grace Sun

2014-01-01

Two wood plastic composite (WPC) boards, one experimental and one commercial, were exposed to exterior conditions and evaluated non-destructively using a clinical magnetic resonance imaging (MRI) unit for moisture content (MC) and distribution. The experimental board was exposed in Vancouver, British Columbia, for more than 8 years, and the commercial board was exposed...

Effects of prenatal and postnatal exposure of Wi-Fi on development of teeth and changes in teeth element concentration in rats. [corrected].

PubMed

Çiftçi, Zülfikar Zahit; Kırzıoğlu, Zühal; Nazıroğlu, Mustafa; Özmen, Özlem

2015-02-01

The present study determined the effects of prenatal and postnatal exposure to Wi-Fi (2.45 GHz)-induced electromagnetic radiation (EMR) on tooth and surrounding tissue development as well as the element levels in growing rats. Twenty-four rats and their offspring were equally divided into two separate groups identified as experiment and control. The experiment group was exposed to 2.45 GHz EMR for 2 h/day during the periods of pregnancy (21 days) and lactation (21 days). The offspring of these dams were also exposed to EMR up to decapitation. The control group was exposed to cage stress for 2 h per day using the same protocol established for the experimental group. On the 7th, 14th, and 21st days after birth, 8 male offspring rats from each of the two groups were decapitated, and the jaws were taken for histological and immunohistochemical examination. Caspase-3 (1/50 dilution) was used in the immunohistochemical examination for apoptotic activity. On the last day of the experiment, the rats' incisors were also collected. In samples that were histologically and immunohistochemically examined, there was an increase in apoptosis and caspase-3 in both the control and the Wi-Fi groups during the development of the teeth. However, no significant difference was observed between the two groups in terms of development and apoptotic activity. Results from the elemental analysis showed that iron and strontium concentrations were increased in the Wi-Fi group, whereas boron, copper, and zinc concentrations were decreased. There were no statistically significant differences in calcium, cadmium, potassium, magnesium, sodium, or phosphorus values between the groups. Histological and immunohistochemical examinations between the experimental and control groups showed that exposure to 2.45 GHz EMR for 2 h per day does not interfere with the development of teeth and surrounding tissues. However, there were alterations in the elemental composition of the teeth, especially affecting such oxidative stress-related elements as copper, zinc, and iron, suggesting that short-term exposure to Wi-Fi-induced EMR may cause an imbalance in the oxidative stress condition in the teeth of growing rats.

Media influence on drive for thinness, body satisfaction, and eating attitudes among young women in Hong Kong and China.

PubMed

Rochelle, Tina L; Hu, W Y

2017-03-01

The present study examined the impact of thin-ideal media exposure on Chinese women's drive for thinness, attitudes towards body shape, and eating attitude. Women were assigned to one of two video conditions, which portrayed the thin-ideal (experimental) or was neutral (control group), in terms of content. A total of 83 young women from Hong Kong (N = 38) and Shanghai (N = 45), aged between 18 and 25 years (M age  = 22.7) participated in the study. A significant interaction was observed between the experimental video condition and location. Hong Kong women in the experimental group experienced greater levels of body dissatisfaction than Shanghai women exposed to the same condition. Exposure to thin-ideal media produced an increase in drive for thinness, body dissatisfaction and problematic eating attitudes regardless of location, with a greater immediate impact shown in Hong Kong women.

An Intervention for the Negative Influence of Media on Body Esteem

ERIC Educational Resources Information Center

Haas, Cheryl J.; Pawlow, Laura A.; Pettibone, Jon; Segrist, Dan J.

2012-01-01

Since research suggests that media pressure to be thin causes individuals to have negative feelings about their appearances, this research aimed to test whether exposing college students to some common myths about female images in the media may be part of the solution to fostering a healthier body image. In this study, a 2 (Group: Experimental or…

Concept Mapping as a Reading Strategy: Does It Scaffold Comprehension and Recall?

ERIC Educational Resources Information Center

Tajeddin, Zia; Tabatabaei, Soudabeh

2016-01-01

Concept maps reflect the linkage of concepts or facts within a text. This study was set out to investigate whether concept mapping as a learning strategy would have any scaffolding effect on the reading comprehension and recall of propositions by L2 learners. Out of 60 high school students, 30 in the experimental group were exposed to concept…

Prediction of microcracking in composite laminates under thermomechanical loading

NASA Technical Reports Server (NTRS)

Maddocks, Jason R.; Mcmanus, Hugh L.

1995-01-01

Composite laminates used in space structures are exposed to both thermal and mechanical loads. Cracks in the matrix form, changing the laminate thermoelastic properties. An analytical methodology is developed to predict microcrack density in a general laminate exposed to an arbitrary thermomechanical load history. The analysis uses a shear lag stress solution in conjunction with an energy-based cracking criterion. Experimental investigation was used to verify the analysis. Correlation between analysis and experiment is generally excellent. The analysis does not capture machining-induced cracking, or observed delayed crack initiation in a few ply groups, but these errors do not prevent the model from being a useful preliminary design tool.

Effects of Wi-Fi (2.45 GHz) Exposure on Apoptosis, Sperm Parameters and Testicular Histomorphometry in Rats: A Time Course Study

PubMed Central

Shokri, Saeed; Soltani, Aiob; Kazemi, Mahsa; Sardari, Dariush; Mofrad, Farshid Babapoor

2015-01-01

Objective In today’s world, 2.45-GHz radio-frequency radiation (RFR) from industrial, scientific, medical, military and domestic applications is the main part of indoor-outdoor electromagnetic field exposure. Long-term effects of 2.45-GHz Wi-Fi radiation on male reproductive system was not known completely. Therefore, this study aimed to investigate the major cause of male infertility during short- and long-term exposure of Wi-Fi radiation. Materials and Methods This is an animal experimental study, which was conducted in the Department of Anatomical Sciences, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, IRAN, from June to August 2014. Three-month-old male Wistar rats (n=27) were exposed to the 2.45 GHz radiation in a chamber with two Wi-Fi antennas on opposite walls. Animals were divided into the three following groups: I. control group (n=9) including healthy animals without any exposure to the antenna, II. 1-hour group (n=9) exposed to the 2.45 GHz Wi-Fi radiation for 1 hour per day during two months and III.7-hour group (n=9) exposed to the 2.45 GHz Wi-Fi radiation for 7 hours per day during 2 months. Sperm parameters, caspase-3 concentrations, histomorphometric changes of testis in addition to the apoptotic indexes were evaluated in the exposed and control animals. Results Both 1-hour and 7-hour groups showed a decrease in sperm parameters in a time dependent pattern. In parallel, the number of apoptosis-positive cells and caspase-3 activity increased in the seminiferous tubules of exposed rats. The seminal vesicle weight reduced significantly in both1-hour or 7-hour groups in comparison to the control group. Conclusion Regarding to the progressive privilege of 2.45 GHz wireless networks in our environment, we concluded that there should be a major concern regarding the timedependent exposure of whole-body to the higher frequencies of Wi-Fi networks existing in the vicinity of our living places. PMID:26199911

Effects of Sleep after Experimental Trauma on Intrusive Emotional Memories

PubMed Central

Kleim, Birgit; Wysokowsky, Julia; Schmid, Nuria; Seifritz, Erich; Rasch, Björn

2016-01-01

Study Objectives: To investigate sleep's effect in the immediate aftermath of experiencing an analog trauma in the laboratory on reducing intrusive emotional memory formation. Methods: Sixty-five healthy women were exposed to an experimental laboratory trauma. They viewed a neutral and a trauma film in the laboratory and were randomly allocated to either a group that slept following film viewing or a group that remained awake. Sleep was recorded with electroencephalogram in a subgroup of participants in the sleep group. All participants recorded intrusive memories in the week following the film. Results: The sleep group experienced fewer and less distressing intrusive trauma memories compared to the wake group. These effects were particularly evident toward the end of the week. Duration spent in stage N2 as opposed to light N1 sleep, a higher number of fast parietal sleep spindles and a lower rapid eye movement sleep density predicted intrusion frequency. Conclusions: Our results have clinical implications and set the ground for early-intervention sleep studies following trauma and prevention of chronic posttrauma disorders. Citation: Kleim B, Wysokowsky J, Schmid N, Seifritz E, Rasch B. Effects of sleep after experimental trauma on intrusive emotional memories. SLEEP 2016;39(12):2125–2132. PMID:27748249

Petroselinum Crispum is Effective in Reducing Stress-Induced Gastric Oxidative Damage.

PubMed

Akıncı, Ayşin; Eşrefoğlu, Mukaddes; Taşlıdere, Elif; Ateş, Burhan

2017-01-01

Oxidative stress has been shown to play a principal role in the pathogenesis of stress-induced gastric injury. Parsley (Petroselinum crispum) contains many antioxidants such as flavanoids, carotenoids and ascorbic acid. In this study, the histopathological and biochemical results of nutrition with a parsley-rich diet in terms of eliminating stress-induced oxidative gastric injury were evaluated. Animal experimentation. Forty male Wistar albino rats were divided into five groups: control, stress, stress + standard diet, stress + parsley-added diet and stress + lansoprazole (LPZ) groups. Subjects were exposed to 72 hours of fasting and later immobilized and exposed to the cold at +4 degrees for 8 hours to create a severe stress condition. Samples from the animals' stomachs were arranged for microscopic and biochemical examinations. Gastric mucosal injury was obvious in rats exposed to stress. The histopathologic damage score of the stress group (7.00±0.57) was higher than that of the control group (1.50±0.22) (p<0.05). Significant differences in histopathologic damage score were found between the stress and stress + parsley-added diet groups (p<0.05), the stress and stress + standard diet groups (p<0.05), and the stress and stress + LPZ groups (p<0.05). The mean tissue malondialdehyde levels of the stress + parsley-added group and the stress + LPZ group were lower than that of the stress group (p<0.05). Parsley supported the cellular antioxidant system by increasing the mean tissue glutathione level (53.31±9.50) and superoxide dismutase (15.18±1.05) and catalase (16.68±2.29) activities. Oral administration of parsley is effective in reducing stress-induced gastric injury by supporting the cellular antioxidant defence system.

Petroselinum Crispum is Effective in Reducing Stress-Induced Gastric Oxidative Damage

PubMed Central

Akıncı, Ayşin; Eşrefoğlu, Mukaddes; Taşlıdere, Elif; Ateş, Burhan

2017-01-01

Background: Oxidative stress has been shown to play a principal role in the pathogenesis of stress-induced gastric injury. Parsley (Petroselinum crispum) contains many antioxidants such as flavanoids, carotenoids and ascorbic acid. Aims: In this study, the histopathological and biochemical results of nutrition with a parsley-rich diet in terms of eliminating stress-induced oxidative gastric injury were evaluated. Study Design: Animal experimentation Methods: Forty male Wistar albino rats were divided into five groups: control, stress, stress + standard diet, stress + parsley-added diet and stress + lansoprazole (LPZ) groups. Subjects were exposed to 72 hours of fasting and later immobilized and exposed to the cold at +4 degrees for 8 hours to create a severe stress condition. Samples from the animals’ stomachs were arranged for microscopic and biochemical examinations. Results: Gastric mucosal injury was obvious in rats exposed to stress. The histopathologic damage score of the stress group (7.00±0.57) was higher than that of the control group (1.50±0.22) (p<0.05). Significant differences in histopathologic damage score were found between the stress and stress + parsley-added diet groups (p<0.05), the stress and stress + standard diet groups (p<0.05), and the stress and stress + LPZ groups (p<0.05). The mean tissue malondialdehyde levels of the stress + parsley-added group and the stress + LPZ group were lower than that of the stress group (p<0.05). Parsley supported the cellular antioxidant system by increasing the mean tissue glutathione level (53.31±9.50) and superoxide dismutase (15.18±1.05) and catalase (16.68±2.29) activities. Conclusion: Oral administration of parsley is effective in reducing stress-induced gastric injury by supporting the cellular antioxidant defence system. PMID:28251024

Ameliorative effects of nano-elemental selenium against hexavalent chromium-induced apoptosis in broiler liver.

PubMed

Xueting, Liu; Rehman, Mujeeb Ur; Mehmood, Khalid; Huang, Shucheng; Tian, Xinxin; Wu, Xiaoxing; Zhou, Donghai

2018-06-01

The current study examined the ameliorative effects of nano-elemental selenium (Nano-Se) against chromium-VI (K 2 Cr 2 O 7 )-induced apoptosis in chickens. The expression of apoptosis-related genes was evaluated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot. A total of 60, one-day-old broiler chickens allotted to six equal groups, i.e., control group (standard diet), Cr(VI)-exposed group (K 2 Cr 2 O 7 via drinking water), Nano-Se group (Nano-Se at 0.5 mg/kg via diet), protection group (K 2 Cr 2 O 7  + Nano-Se), cure group (K 2 Cr 2 O 7 for initial 2 weeks and then Nano-Se), and prevention group (opposite to the cure group) and were detected by the activities of pro-apoptosis (Bax, Caspase-3) and anti-apoptosis (Bcl-2) genes expression at day 35 of the experiment. Intense apoptosis was observed in liver tissues of chickens exposed to K 2 Cr 2 O 7 . The Nano-Se supplementation caused a significant decrease (P < 0.01) in the mRNA expression levels of Bax and Caspase-3 genes, while significantly elevated (P < 0.05) mRNA expression level of Bcl-2 gene was observed in Nano-Se experimental groups as compare to control and Cr(VI)-exposed group. The results quantified by the RT-qPCR were further confirmed by the western blot analysis. Altogether, these results suggest anti-apoptotic effects of Nano-Se in the chicken liver, which is interesting for further study. The present findings suggested that Nano-Se has protective effects against K 2 Cr 2 O 7 -induced apoptosis in broilers liver and can serve a key role as a protective agent against apoptosis.

Chronic consumption of distilled sugarcane spirit induces anxiolytic-like effects in mice

PubMed Central

Sena, Maria Clécia P; Nunes, Fabíola C; Stiebbe Salvadori, Mirian G S; Carvalho, Cleyton Charles D; Morais, Liana Clébia S L; Braga, Valdir A

2011-01-01

OBJECTIVE: Chronic ethanol consumption is a major public health problem throughout the world. We investigated the anxiolytic-like effects and the possible ever injury induced by the chronic consumption of ethanol or sugarcane spirit in mice. METHOD: Adult mice were exposed to a two-bottle free-choice paradigm for 6 weeks. The mice in Group A (n  =  16) had access to sugarcane spirit + distilled water, the mice in Group B (n  =  15) had access to ethanol + distilled water, and the mice in Group C (control, n  =  14) had access to distilled water + distilled water. The ethanol content in the beverages offered to Groups A and B was 2% for the first week, 5% for the second week and 10% for the remaining four weeks. At the end of the experimental period, the mice were evaluated using the elevated-plus maze and the hole-board test to assess their anxiety-related behaviors. We also determined the serum aspartate aminotransferase and alanine aminotransferase levels. RESULTS: In the elevated-plus maze, the time spent in the open arms was increased in the mice exposed to chronic ethanol (32 ± 8 vs. 7 ± 2 s, n  =  9) or sugarcane spirit (36 ± 9 vs. 7 ± 2 s, n  =  9) compared to the controls. In the hole-board test, the mice exposed to ethanol or sugarcane spirit displayed increases in their head-dipping frequency (16 ± 1 for the control group, 27 ± 2 for the ethanol group, and 31 ± 3 for the sugarcane-spirit group; n  =  9 for each group). In addition, the mice exposed to sugarcane spirit displayed an increase in the aspartate aminotransferase / alanine aminotransferase ratio compared to the ethanol group (1.29 ± 0.17 for the control group and 2.67 ± 0.17 for the sugarcane spirit group; n  =  8 for each group). CONCLUSION: The chronic consumption of sugarcane-spirit produces liver injury and anxiolytic-like effects and the possible liver injury in mice. PMID:21789394

[Effects of radiation emitted from mobile phones on short- term heart rate variability parameters].

PubMed

Yıldız, Metin; Yılmaz, Derya; Güler, Inan; Akgüllü, Cağdaş

2012-08-01

In this study, the effects of radiation emitted from mobile phone (MP) on heart rate variability (HRV) which is accepted a non-invasive indicator of autonomic nervous system (ANS) were investigated with considering the deficiency of previous studies. A randomized controlled study has been designed and utilized with 30 young and healthy volunteers. During the experiment that had three periods, the electrocardiogram (ECG) and respiration signals were recorded and MP was attached to subjects' right ear with a bone. Ten subjects selected randomly were exposed to high -level radiation during the second period (Experimental Group 1). Ten of others were exposed during the third period with maximum level radiation (Experimental Group 2). Ten records were also made while MP was closed as a control. Short -term HRV parameters were obtained and repeated measures ANOVA and suitable post-hoc tests applied to the results. According to the results of the repeated measures ANOVA; there were no significant main effects of groups. However, there were some significant differences in measuring time periods and groups*period interactions. The post-hoc tests showed that mean R to R interval and HF power are significantly changed by maximum radiation emitted from MP. Due to the radiation emitted from MPs at maximum power, some changes may occur in HRV parameters that are associated with increased parasympathetic activity. But, the level of these changes is similar to daily activities as excitement, and stand up.

Effect of extremely low frequency electromagnetic field on brain histopathology of Caspian Sea Cyprinus carpio.

PubMed

Samiee, Farzaneh; Samiee, Keivandokht

2017-01-01

There is limited research on the effect of electromagnetic field on aquatic organisms, especially freshwater fish species. This study was conducted to evaluate the effect of extremely low frequency electromagnetic field (ELF-EMF) (50 Hz) exposure on brain histopathology of Cyprinus carpio, one of the important species of Caspian Sea with significant economic value. A total of 200 healthy fish were used in this study. They were classified randomly in two groups: sham-exposed group and experimental group, which were exposed to five different magnetic field intensities (0.1, 1, 3, 5, and 7 mT) at two different exposure times (0.5 and 1 h). Histologic results indicate that exposure of C. carpio to artificial ELF-EMF caused severe histopathological changes in the brain at field intensities ≥3 mT leading to brain necrosis. Field intensity and duration of exposure were key parameters in induction of lesion in the brain. Further studies are needed to elucidate exact mechanism of EMF exposure on the brain.

[p16 and MGMT gene methylation in sputum cells of uranium workers].

PubMed

Su, Shi-biao; Yang, Lu-jing; Zhang, Wei; Jin, Ya-li; Nie, Ji-hua; Tong, Jian

2006-02-01

To study the methylation of O-6-methylguanine-DNA methyltransferase (MGMT) and p16 gene in the sputum cells of radon-exposed population. To provide the experimental base for finding the molecular biomarker of the high risk population of the radon-induced lung cancer. 91 radon-exposed workers were divided into 4 groups, high dosage group (> 120 WLM), middle dosage group (between 60 and 120 WLM), low dosage group (between 30 and 60 WLB) and lower dosage group (between 2 and 30 WLM) according to the accumulated exposure dosage of the radon daughters. The abnormal methylation of p16 and MGMT gene in the sputum cells of the population in the four groups was detected with the methylation specific PCR (MSP). There was significantly upward trend for the p16 gene methylation rate (0.00%-20.00%), the MGMT gene methylation rate (0.00%-28.00%) and the total methylation rate (0.00%-40.00%) with the increase of the accumulated exposure dosage of the radon daughters (P < 0.01). The methylation of p16 and MGMT gene is related to the accumulate exposure dosage of the radon daughters.

Group Effects on Individual Attitudes Toward Social Responsibility.

PubMed

Secchi, Davide; Bui, Hong T M

2018-01-01

This study uses a quasi-experimental design to investigate what happens to individual socially responsible attitudes when they are exposed to group dynamics. Findings show that group engagement increases individual attitudes toward social responsibility. We also found that individuals with low attitudes toward social responsibility are more likely to change their opinions when group members show more positive attitudes toward social responsibility. Conversely, individuals with high attitudes do not change much, independent of group characteristics. To better analyze the effect of group dynamics, the study proposes to split social responsibility into relative and absolute components. Findings show that relative social responsibility is correlated with but different from absolute social responsibility although the latter is more susceptible than the former to group dynamics.

N-acetylcysteine improves established monocrotaline-induced pulmonary hypertension in rats

PubMed Central

2014-01-01

Background The outcome of patients suffering from pulmonary arterial hypertension (PAH) are predominantly determined by the response of the right ventricle to the increase afterload secondary to high vascular pulmonary resistance. However, little is known about the effects of the current available or experimental PAH treatments on the heart. Recently, inflammation has been implicated in the pathophysiology of PAH. N-acetylcysteine (NAC), a well-known safe anti-oxidant drug, has immuno-modulatory and cardioprotective properties. We therefore hypothesized that NAC could reduce the severity of pulmonary hypertension (PH) in rats exposed to monocrotaline (MCT), lowering inflammation and preserving pulmonary vascular system and right heart function. Methods Saline-treated control, MCT-exposed, MCT-exposed and NAC treated rats (day 14–28) were evaluated at day 28 following MCT for hemodynamic parameters (right ventricular systolic pressure, mean pulmonary arterial pressure and cardiac output), right ventricular hypertrophy, pulmonary vascular morphometry, lung inflammatory cells immunohistochemistry (monocyte/macrophages and dendritic cells), IL-6 expression, cardiomyocyte hypertrophy and cardiac fibrosis. Results The treatment with NAC significantly decreased pulmonary vascular remodeling, lung inflammation, and improved total pulmonary resistance (from 0.71 ± 0.05 for MCT group to 0.50 ± 0.06 for MCT + NAC group, p < 0.05). Right ventricular function was also improved with NAC treatment associated with a significant decrease in cardiomyocyte hypertrophy (625 ± 69 vs. 439 ± 21 μm2 for MCT and MCT + NAC group respectively, p < 0.001) and heart fibrosis (14.1 ± 0.8 vs. 8.8 ± 0.1% for MCT and MCT + NAC group respectively, p < 0.001). Conclusions Through its immuno-modulatory and cardioprotective properties, NAC has beneficial effect on pulmonary vascular and right heart function in experimental PH. PMID:24929652

Effect of Ginseng on Calretinin Expression in Mouse Hippocampus Following Exposure to 835 MHz Radiofrequency

PubMed Central

Aryal, Bijay; Maskey, Dhiraj; Kim, Myeung-Ju; Yang, Jae-Won; Kim, Hyung-Gun

2011-01-01

Exponential rise in the use of mobile communication devices has generated health concerns due to radiofrequency (RF) exposure due to its close proximity to the head. Calcium binding proteins like calretinin regulate the levels of calcium (Ca2+) which plays an important role in biological systems. Ginseng is known for maintaining equilibrium in the human body and may play a beneficial radioprotectant role against electromagnetic field (EMF) exposure. In the present study, we evaluated the radioprotective effects of red ginseng (RG) extract in a mouse model. Calretinin (CR) expression was measured using a free-floating immunohistochemical method in the hippocampus of mice after 835 MHz EMF exposure for 5 h/d for 5 d at specific absorption rate=1.6 W/kg for the different experimental groups. The control animals were treated with NaCl while the experimental animals received 10 mg/kg ginseng, or 30 mg/kg; EMF exposed mice were also treated with NaCl, 10 mg/kg ginseng (E10), or 30 mg/kg (E30). Decreases in CR immunoreactivity (IR) along with loss of CA1 and CA3 interneurons and infragranular cells were observed in the ENaCl group while such losses were not observed in the E10 and E30 groups. CR IR significantly increased in the RG-treated group compared to control and EMF-exposed groups treated with NaCl. The study demonstrates that RG extract can serve as a radioprotective agent that maintains Ca2+ homeostasis and prevents neuronal loss in the brain hippocampal region caused by RF exposure. PMID:23717055

Kinetics of styrene in workers from a plastics industry after controlled exposure: a comparison with subjects not previously exposed.

PubMed Central

Löf, A; Lundgren, E; Nordqvist, M B

1986-01-01

Eight male workers from a glass reinforced plastics industry were experimentally exposed for 2 hours to 2.84 mmol/m3 (296 mg/m3) styrene during light physical exercise (50 W). About 63% of the amount supplied (4.6 mmol styrene) was taken up in the body. The arterial blood concentration of styrene reached a relatively stable level of 15 mumol/l at the end of exposure which was about 70% of the blood concentration in a group of volunteers with no previous exposure to solvents. The apparent blood clearance was significantly higher in the occupationally exposed subjects 2.01/h X kg compared with 1.51/h X kg. Contrary to the relatively stable level of styrene at the end of exposure the concentration of non-conjugated styrene glycol increased throughout the exposure and reached about 3 mumol/l in both groups. Like styrene, the non-conjugated styrene glycol seemed to be eliminated faster from the occupationally exposed workers. The blood concentration of styrene-7,8-oxide was low and seldom exceeded the detection limit of 0.02 mumol/l. The results show that long term exposure in a glass reinforced plastics industry may facilitate the metabolism of styrene. PMID:3730303

Growth Retardation Of Chick Embryo Exposed To A Low Dose Of Electromagnetic Waves.

PubMed

Siddiqi, Najam; John C, Muthusami; Norrish, Mark; Heming, Thomas

2016-01-01

The objectives of this study were to explore the effects of low dose of the nonionizing (REW) emitted by a mobile phone on the development of chick embryo. one hundred and twenty chick fertilized eggs were equally divided into a control and an exposed group. Sixty fertilized eggs were placed in an egg incubator with a mobile phone (SAR US: 1.10W/kg (head) 0.47 W/kg body) in silent mode having vibration disable mode. Mobile was called for a total of 20 minutes in 24 hours. Twenty embryos each were sacrificed at day 5, 10 and 15, mortality, wet body weight, head to rump length, eye diameter and morphological changes were noted. The control group, 60 eggs were incubated in the same conditions, having removed the phone. No mortality was noted. The experimental group exposed to REW showed subcutaneous haemorrhagic areas and significant growth retardation at day 10 as evidence by smaller eye diameter, wet weight and CR length than the control group. There were no significant growth differences at either day 5 or at day 15. Electromagnetic waves emitted from mobile phones even though for a very short duration of 20 minutes per day have affected the growth of the chick embryo at day 10 of incubation, Hence exposure of these waves are not 100% safe.

NMR-based metabolomic study on the toxicological effects of pesticide, diazinon on adaptation to sea water by endangered Persian sturgeon, Acipenser persicus fingerlings.

PubMed

Hajirezaee, Saeed; Mirvaghefi, Alireza; Farahmand, Hamid; Agh, Naser

2017-10-01

NMR-based metabolomics was applied to explore metabolic impacts of diazinon on sea water adaptation of Persian sturgeon fingerlings, Acipenser persicus. Fingerlings were exposed to sub-lethal concentrations of diazinon in freshwater (FW) for 96 h (short-term trial) and 12 days (long-term trial) and then exposed in brackish water (BW) (12 mg L -1 salinity) for 24 h. After 96 h and 12 days exposure in FW, identified metabolites (amino acids, osmolytes, energy metabolites) showed different change-patterns compared to control group (P < 0.05) as follow: (A) short-term trial: higher plasma levels of glucose, lactate (in all diazinon-exposed fish), acetate and acetoacetate (in 0.9 mg L -1 diazinon treatment); lower levels of creatine (in all diazinon-exposed fish), trimethylamine-N-oxide, choline, taurine, betaine, N,N-dimethylglycine and almost all amino acids in fish exposed to high concentrations of diazinon (0.54 and 0.9 mg L -1 diazinon). (B) Long-term trial: higher plasma levels of lipid oxidation metabolites and almost all amino acids in fish exposed to 0.54 and 0.9 mg L -1 diazinon; lower levels of creatine, trimethylamine-N-oxide, N,N-dimethylglycine, betaine, choline (in all diazinon-exposed fish), glucose (in 0.54 and 0.9 mg L -1 diazinon treatments) and taurine (in 0.9 mg L -1 diazinon treatment). When fish were exposed in BW for 24 h, the plasma levels of osmolytes decreased significantly in almost all experimental groups of short-term and long-term trial (P < 0.05). In short-term trial, the plasma levels of glucose in all groups and lactate in 0.18 and 0.54 mg L -1 diazinon treatments increased after salinity challenge (P < 0.05). However, a significant decrease was observed in lactate levels in 0.9 mg L -1 diazinon treatment (P < 0.05). Also, the plasma levels of amino acids decreased mostly in fish of control group than exposed fish (P < 0.05). The plasma glycerol concentration showed a significant decrease only in fish of 0.54 mg L -1 diazinon treatment (P < 0.05). In long term trial, the energetic metabolites (acetate, acetoacetate, glycerol) showed significant increases mostly in fish exposed to high concentrations of diazinon (P < 0.05). Phosphocreatine was detected only in groups exposed to 0.54 and 0.9 mg L -1 diazinon. Some amino acids decreased in control and diazinon-exposed groups while glycine (in control and 0.18 mg L -1 diazinon treatment), glutamine and alanine (in 0.9 mg L -1 diazinon treatment) elevated significantly after 24 h acclimation in BW (P < 0.05). Our results may help to understand the effects of pesticides on fish osmoregulation from a metabolic approach. Copyright © 2017. Published by Elsevier Ltd.

Prenatal testosterone exposure worsen the reproductive performance of male rat at adulthood.

PubMed

Ramezani Tehrani, Fahimeh; Noroozzadeh, Mahsa; Zahediasl, Saleh; Ghasemi, Asghar; Piryaei, Abbas; Azizi, Fereidoun

2013-01-01

The reproductive system is extremely susceptible to environmental insults, for example exogenous steroids during gestational development and differentiation. Experimental induction of androgen excess during prenatal life in female animal models reprograms their reproductive physiology, however the fetal programming of the male reproductive system by androgen excess has not been well studied. We aimed to determine the effect of prenatal exposure of two different doses of testosterone on different gestational days, on the male reproductive system using a rat model. Sixteen pregnant rats were randomly divided into two experimental groups and two control groups. Experimental group І were subcutaneously injected with 3 mg free testosterone on gestational days 16-19 and its controls received solvent for that time; experimental group П were subcutaneously injected with 20 mg free testosterone on day 20 of gestational period and its controls received solvent at the same time. The reproductive system morphology and function of 32 male offspring of these study groups were compared at days 6-30-60 of age and after puberty. The anogenital distance of the male offspring of both experimental groups had no significant differences on the different days of measurement, compared with controls. In the offspring of experimental group І, the testes weight, number of Sertoli, Spermatocyte and Spermatid cells, sperm count and motility and the serum concentration of testosterone after puberty were significantly decreased; except for reduction of sperm motility (p< 0.01), the other effects were not observed in the offspring of experimental group ІІ. In summary, our data show that prenatal exposure of male rat fetuses to excess testosterone disrupted reproductive function, an effect highly dependent on the time, duration and level of exposure. It seems that the reproductive system in individuals exposed to high levels of androgens during fetal life should be evaluated at puberty and likely to be treated.

Prenatal Testosterone Exposure Worsen the Reproductive Performance of Male Rat at Adulthood

PubMed Central

Ramezani Tehrani, Fahimeh; Noroozzadeh, Mahsa; Zahediasl, Saleh; Ghasemi, Asghar; Piryaei, Abbas; Azizi, Fereidoun

2013-01-01

The reproductive system is extremely susceptible to environmental insults, for example exogenous steroids during gestational development and differentiation. Experimental induction of androgen excess during prenatal life in female animal models reprograms their reproductive physiology, however the fetal programming of the male reproductive system by androgen excess has not been well studied. We aimed to determine the effect of prenatal exposure of two different doses of testosterone on different gestational days, on the male reproductive system using a rat model. Sixteen pregnant rats were randomly divided into two experimental groups and two control groups. Experimental group І were subcutaneously injected with 3 mg free testosterone on gestational days 16-19 and its controls received solvent for that time; experimental group П were subcutaneously injected with 20 mg free testosterone on day 20 of gestational period and its controls received solvent at the same time. The reproductive system morphology and function of 32 male offspring of these study groups were compared at days 6-30-60 of age and after puberty. The anogenital distance of the male offspring of both experimental groups had no significant differences on the different days of measurement, compared with controls. In the offspring of experimental group І, the testes weight, number of Sertoli, Spermatocyte and Spermatid cells, sperm count and motility and the serum concentration of testosterone after puberty were significantly decreased; except for reduction of sperm motility (p< 0.01), the other effects were not observed in the offspring of experimental group ІІ. In summary, our data show that prenatal exposure of male rat fetuses to excess testosterone disrupted reproductive function, an effect highly dependent on the time, duration and level of exposure. It seems that the reproductive system in individuals exposed to high levels of androgens during fetal life should be evaluated at puberty and likely to be treated. PMID:23967236

Myocardial fibrosis in rats exposed to low frequency noise.

PubMed

Antunes, Eduardo; Oliveira, Pedro; Borrecho, Gonçalo; Oliveira, Maria João R; Brito, José; Aguas, Artur; Martins, Dos Santos José

2013-06-01

Low frequency noise (LFN) characterized by large pressure amplitude (> or =90 dB SPL) and low frequency bands (< or =500 Hz) can lead to structural and ultrastructural modifications in the extracellular matrix of several tissues, with an abnormal proliferation of collagen and development of fibrosis. It is not known whether LFN induces similar structural alterations in the ventricular myocardium of rats. The aim of this study was to evaluate and measure the myocardial fibrosis induced by LFN. Two groups of rats were considered: group A with 26 rats continuously exposed to LFN during a period of 3 months; group B with 20 control rats.The hearts were sectioned from the ventricular apex to the atria and the mid-ventricular fragment was selected. Chromotrope-aniline blue (CAB) staining was used for histological observation. The measurement of fibrosis was performed using the computer image analysis Image J software. Histological observation with CAB staining showed the presence of collagen deposition between the cardiomyocytes. Fibrosis increased 97.5%, 81.5% and 83.7%, respectively, in the left ventricle, interventricular septum and right ventricle, in exposed rats (P <0.001).The ratio fibrosis/muscle in left ventricle, interventricular septum and right ventricle was significantly higher in LFN exposed rats (P< 0.001). Our study demonstrates a significant myocardial fibrosis induced by low frequency noise in rats. Our results reinforce the need for further experimental and clinical investigations concerning the effects of low frequency noise on the heart.

Influence of electromagnetic fields and protective effect of CAPE on bone mineral density in rats.

PubMed

Yildiz, Mustafa; Cicek, Ekrem; Cerci, Sevim Sureyya; Cerci, Celal; Oral, Baha; Koyu, Ahmet

2006-10-01

Most mobile phones emit electromagnetic radiation at 900 MHz or 1800 MHz. An electromagnetic field has some biological effects on the behavior of the cell population of bone. The aim of this work is to evaluate the effects of the radiation emitted by mobile phones on bone mineral density (BMD). The effects of caffeic acid phenethyl ester (CAPE) on the radiation-induced changes were also investigated. In the study, 48 Sprague Dawley rats were used. Rats were divided into five groups as follows: control, irradiated with 900 MHz, irradiated with 900 MHz and treatment, irradiated with 1800 MHz, irradiated with 1800 MHz and treatment groups. The rats in the control group (first group) were left within the experimental setup during 30 min/day for 28 days without radiation exposure. Nine hundred-MHz radiation group was exposed to irradiate both second and third groups for 28 days (30 min/day); 1800-MHz radiation group was exposed to irradiate both fourth and fifth groups for 28 days (30 min/day). Third and fifth groups were also treated by CAPE for 28 days. Treatment groups received 10 microml/kg/day CAPE i.p. before the irradiation. Bone mineral densities were determined in all groups. BMD was found to be decreased in the irradiated groups and to be increased in the treatment groups. The changes were not significant (p >0.05).

Can’t Count or Won’t Count? Embedding Quantitative Methods in Substantive Sociology Curricula: A Quasi-Experiment

PubMed Central

Williams, Malcolm; Sloan, Luke; Cheung, Sin Yi; Sutton, Carole; Stevens, Sebastian; Runham, Libby

2015-01-01

This paper reports on a quasi-experiment in which quantitative methods (QM) are embedded within a substantive sociology module. Through measuring student attitudes before and after the intervention alongside control group comparisons, we illustrate the impact that embedding has on the student experience. Our findings are complex and even contradictory. Whilst the experimental group were less likely to be distrustful of statistics and appreciate how QM inform social research, they were also less confident about their statistical abilities, suggesting that through ‘doing’ quantitative sociology the experimental group are exposed to the intricacies of method and their optimism about their own abilities is challenged. We conclude that embedding QM in a single substantive module is not a ‘magic bullet’ and that a wider programme of content and assessment diversification across the curriculum is preferential. PMID:27330225

Argumentation Practices in Classroom: Pre-service teachers' conceptual understanding of chemical equilibrium

NASA Astrophysics Data System (ADS)

Kaya, Ebru

2013-05-01

This study examines the impact of argumentation practices on pre-service teachers' understanding of chemical equilibrium. The sample consisted of 100 pre-service teachers in two classes of a public university. One of these classes was assigned as experimental and the other as control group, randomly. In the experimental group, the subject of chemical equilibrium was taught by using argumentative practices and the participants were encouraged to participate in the lessons actively. However, the instructor taught the same subject by using the lecturing method without engaging argumentative activities in the control group. The Chemical Equilibrium Concept Test and Written Argumentation Survey were administered to all participants to assess their conceptual understanding and the quality of their arguments, respectively. The analysis of covariance results indicate that argumentation practices significantly improved conceptual understanding of the experimental group when compared to the control group. Furthermore, the results show that the pre-service teachers exposed to argumentative practices constructed more quality arguments than those in the control group after the instruction. Based on these results, it can be concluded that the instruction based on argumentative practices is effective in concept teaching in science education. Therefore, argumentation should be explicitly taught in teacher education besides elementary and secondary education.

Immunohistopathologic demonstration of deleterious effects on growing rat testes of radiofrequency waves emitted from conventional Wi-Fi devices.

PubMed

Atasoy, Halil I; Gunal, Mehmet Y; Atasoy, Pinar; Elgun, Serenay; Bugdayci, Guler

2013-04-01

To investigate effects on rat testes of radiofrequency radiation emitted from indoor Wi-Fi Internet access devices using 802.11.g wireless standards. Ten Wistar albino male rats were divided into experimental and control groups, with five rats per group. Standard wireless gateways communicating at 2.437 GHz were used as radiofrequency wave sources. The experimental group was exposed to radiofrequency energy for 24 h a day for 20 weeks. The rats were sacrificed at the end of the study. Intracardiac blood was sampled for serum 8-hydroxy-2'-deoxyguanosine levels. Testes were removed and examined histologically and immunohistochemically. Testis tissues were analyzed for malondialdehyde levels and prooxidant-antioxidant enzyme activities. We observed significant increases in serum 8-hydroxy-2'-deoxyguanosine levels and 8-hydroxyguanosine staining in the testes of the experimental group indicating DNA damage due to exposure (p < 0.05). We also found decreased levels of catalase and glutathione peroxidase activity in the experimental group, which may have been due to radiofrequency effects on enzyme activity (p < 0.05). These findings raise questions about the safety of radiofrequency exposure from Wi-Fi Internet access devices for growing organisms of reproductive age, with a potential effect on both fertility and the integrity of germ cells. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Aneugenicity and clastogenicity in freshwater fish Oreochromis niloticus exposed to incipient safe concentration of tannery effluent.

PubMed

Weldetinsae, Abel; Dawit, Mekibib; Getahun, Abebe; Patil, H S; Alemayehu, Esayas; Gizaw, Melaku; Abate, Moa; Abera, Daniel

2017-04-01

Conventional effluent bioassays mostly rely on overt responses or endpoints such as apical and Darwinian fitness. Beyond the empirical observation, laboratory toxicity testing needs to rely on effective detection of prognostic biomarkers such as genotoxicity. Indeed, characterization of tannery effluent requires slotting in of genotoxic responses in whole effluent toxicity testing procedures. Hence, the prime objective of the present experimental investigation is to apply the technique of biological assay as a tool of toxicity testing to evaluate the induction of micronuclei (MN) in peripheral erythrocytes, and exfoliated cells of gill and kidney of O.niloticus exposed to Maximum tolerable concentrations (MTCs) of composite Modjo tannery effluent (CMTE) and to compare the sensitivity of each cells origin to the induction of MN. After 72h of exposure, cellular aberrations were detected using MN and nuclear abnormality (NA) tests. The induction of MN was significantly higher in exposed groups (P<0.05) when compared to the control group; moreover the tissue specific MN response was in the order, gill cells>peripheral erythrocyte>kidney. Total NA was found to increase significantly (P<0.05), when compared to the non-exposed group. NA was also further ramified as blebbed (BL), bi-nucleated (BN), lobbed (LB) and notched (NT) abnormalities. The result of each endpoint measured has demonstrated that at a concentration of total chromium (0.1, 0.73 and 1.27mg/L), a perceptible amount cellular aberration was measured, further implicating somber treat of genotoxicity to fishes, if exposed to water contaminated with tannery effluent. This further highlight that conventional effluent monitoring alone cannot reveal the effects expressed at cellular and genetic levels further demanding the incorporation of effluent bioassays in risk assessment and risk management/abatement programs. Copyright © 2016. Published by Elsevier Inc.

Effectiveness of cognitive-behavioural therapy for post-disaster distress in post-traumatic stress symptoms after Chilean earthquake and tsunami.

PubMed

Leiva-Bianchi, Marcelo; Cornejo, Felipe; Fresno, Andrés; Rojas, Carolina; Serrano, Camila

This is the first time that the effectiveness of cognitive-behavioural therapy for post-disaster stress (CBT-PD) in symptoms of posttraumatic stress disorder (PTSD) has been tested outside the United States of America. Quasi-experiment with three groups. In the quasi-control group, complete CBT-PD was applied even though its members did not have PTSD; in quasi-experimental conditions, participants received complete treatment because they had this diagnosis; and in the third group, participants with PTSD received an abbreviated treatment (double sessions) due to organisational requirements. Primary health care workers in Constitución (Chile), city exposed to earthquake and tsunami; public department workers in Talca (city exposed only to earthquake) and teachers from a school (Constitución). A total of 13 of the 91 people diagnosed with PTSD participated. In addition, 16 people without diagnosis voluntarily participated. The treatment was completed by 29 participants. There were no dropouts. Only 1 of the 9 participants in the quasi-experimental group did not respond to treatment. CBT-PD is a group therapy (10-12 sessions) that includes psychoeducation, breathing retraining, behavioural activation and cognitive restructuring. CBT-PD (complete and abbreviated) was applied between September and December 2010. Short Posttraumatic Stress Disorder Rating Interview (SPRINT-E) was used to measure PTSD symptoms before and after treatment. The group that received the complete treatment and was diagnosed with PTSD showed a significant decrease in the total symptoms to below dangerous levels (IGA AB : 31.556; p<0.01; 95%CI: 0.21-2.01]; η 2 =0.709). The effectiveness and benefits of incorporating CBT-PD in the health network after events like disasters were discussed. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Further data on the effects of subliminal symbiotic stimulation on schizophrenics.

PubMed

Kaplan, R; Thornton, P; Silverman, L

1985-11-01

This investigation further examined the effects of activating unconscious symbiotic fantasies in schizophrenics. One hundred twenty-eight hospitalized schizophrenic men who qualified as "relatively differentiated" on the Adjective Rating Scale were randomly assigned to four groups. Each group was assessed for pathological thinking, pathological nonverbal behavior, and self-esteem before and after the subliminal exposure of an experimental and control stimulus. The control stimulus for all groups was the message PEOPLE ARE WALKING and the experimental stimuli were the messages MOMMY AND I ARE ONE, MOMMY IS ALWAYS WITH ME, MOMMY FEEDS ME WELL, and I CANNOT HURT MOMMY (one for each group). One half of each group was subliminally exposed to verbal messages only and one half to verbal messages accompanied by congruent pictures. The first stimulus (MOMMY AND I ARE ONE) was intended to activate unconscious symbiotic fantasies that in a number of prior studies reduced pathology in groups of relatively differentiated schizophrenics. The other stimuli were intended to activate reassuring unconscious fantasies about "mommy" that were not specifically symbiosis-related. Only the MOMMY AND I ARE ONE stimulus led to more adaptive behavior and did so on all three dependent variables. This supported the supposition, also borne out in two other studies, that it is specifically symbiosis-related gratifications that are ameliorative for schizophrenics. The above results were considerably stronger for the subgroup that was exposed to a picture accompanying the MOMMY AND I ARE ONE message. This was viewed as probably the result of the pictorial representation serving as a concretization of the more abstract verbal message and as such being more relevant to the relatively primitive mode of thinking in schizophrenia.

The Effect of Listening Drills Utilizing Compressed Speech and Standard Speech upon the Listening Comprehension of Second-Grade Children.

ERIC Educational Resources Information Center

Ihnat, Mary Ann

This study was designed to investigate whether the listening ability of second-grade students could be improved using compressed-speech training as compared to normal listening training. The subjects were 95 second-grade pupils in a low-to-middle class suburban community in central New Jersey. The plan was to expose an experimental group to…

QTL mapping of adult plant resistance to Ug99 stem rust in the spring wheat population RB07/MN06113-8

USDA-ARS?s Scientific Manuscript database

The emergence and spread of the Ug99 race group of the stem rust pathogen in the past decade has exposed the vulnerability of wheat to this disease. Discovery of novel and effective sources of resistance is vital to reduce losses. The experimental breeding line MN06113-8 and cultivar RB07 developed ...

TREATMENT OF DYSENTERY IN EXPERIMENTAL RADIATION SICKNESS (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodskaya, E.A.; Emaikina, V.P.; Kostritsa, A.G.

1959-01-01

Experiments with 53 cats (one group exposed to 275 r and the other to 500 r and infected with the Flexner dysentery) showed that the exposure to 275 r did not change the general condition of the cats while the 800 r resulted in a sharp rise of temperature, dirrhea, heavy dystrophic-necrotic changes in the intestines, and peculiar mucous and submucous processes. (R.V.J.)

Field testing of Schistosoma japonicum DNA vaccines in cattle in China.

PubMed

Shi, Fuhui; Zhang, Yaobi; Lin, Jiaojiao; Zuo, Xin; Shen, Wei; Cai, Yiumin; Ye, Ping; Bickle, Quentin D; Taylor, Martin G

2002-11-01

Vaccines are needed to reduce the zoonotic reservoir of Schistosoma japonicum infection in bovines in China. We have developed two experimental DNA vaccines and have already shown these to be capable of inducing partial protection in water buffalo naturally exposed to the risk of S. japonicum infection in the field. We now report a similar field trial in cattle, the other major bovine reservoir host species in China. Groups of cattle were vaccinated with the VRSj28 vaccine or the VRSj23 vaccine, or, to test whether protection could be enhanced by combination vaccination, with both these DNA vaccines together. After vaccination, the cattle were exposed to natural infection in the field for a period of 54 days. Worm and egg counts carried out at the end of the experiment showed that each of the vaccine groups showed partial resistance, and that combined vaccination was not more effective than vaccination with the individual plasmids.

Does Exposure to a Radiofrequency Electromagnetic Field Modify Thermal Preference in Juvenile Rats?

PubMed Central

Pelletier, Amandine; Delanaud, Stéphane; de Seze, René; Bach, Véronique; Libert, Jean-Pierre; Loos, Nathalie

2014-01-01

Some studies have shown that people living near a mobile phone base station may report sleep disturbances and discomfort. Using a rat model, we have previously shown that chronic exposure to a low-intensity radiofrequency electromagnetic field (RF-EMF) was associated with paradoxical sleep (PS) fragmentation and greater vasomotor tone in the tail. Here, we sought to establish whether sleep disturbances might result from the disturbance of thermoregulatory processes by a RF-EMF. We recorded thermal preference and sleep stage distribution in 18 young male Wistar rats. Nine animals were exposed to a low-intensity RF-EMF (900 MHz, 1 V.m−1) for five weeks and nine served as non-exposed controls. Thermal preference was assessed in an experimental chamber comprising three interconnected compartments, in which the air temperatures (Ta) were set to 24°C, 28°C and 31°C. Sleep and tail skin temperature were also recorded. Our results indicated that relative to control group, exposure to RF-EMF at 31°C was associated with a significantly lower tail skin temperature (−1.6°C) which confirmed previous data. During the light period, the exposed group preferred to sleep at Ta = 31°C and the controls preferred Ta = 28°C. The mean sleep duration in exposed group was significantly greater (by 15.5%) than in control group (due in turn to a significantly greater amount of slow wave sleep (SWS, +14.6%). Similarly, frequency of SWS was greater in exposed group (by 4.9 episodes.h−1). The PS did not differ significantly between the two groups. During the dark period, there were no significant intergroup differences. We conclude that RF-EMF exposure induced a shift in thermal preference towards higher temperatures. The shift in preferred temperature might result from a cold thermal sensation. The change in sleep stage distribution may involve signals from thermoreceptors in the skin. Modulation of SWS may be a protective adaptation in response to RF-EMF exposure. PMID:24905635

Does exposure to a radiofrequency electromagnetic field modify thermal preference in juvenile rats?

PubMed

Pelletier, Amandine; Delanaud, Stéphane; de Seze, René; Bach, Véronique; Libert, Jean-Pierre; Loos, Nathalie

2014-01-01

Some studies have shown that people living near a mobile phone base station may report sleep disturbances and discomfort. Using a rat model, we have previously shown that chronic exposure to a low-intensity radiofrequency electromagnetic field (RF-EMF) was associated with paradoxical sleep (PS) fragmentation and greater vasomotor tone in the tail. Here, we sought to establish whether sleep disturbances might result from the disturbance of thermoregulatory processes by a RF-EMF. We recorded thermal preference and sleep stage distribution in 18 young male Wistar rats. Nine animals were exposed to a low-intensity RF-EMF (900 MHz, 1 V x m(-1)) for five weeks and nine served as non-exposed controls. Thermal preference was assessed in an experimental chamber comprising three interconnected compartments, in which the air temperatures (Ta) were set to 24°C, 28°C and 31°C. Sleep and tail skin temperature were also recorded. Our results indicated that relative to control group, exposure to RF-EMF at 31°C was associated with a significantly lower tail skin temperature (-1.6°C) which confirmed previous data. During the light period, the exposed group preferred to sleep at Ta = 31°C and the controls preferred Ta = 28°C. The mean sleep duration in exposed group was significantly greater (by 15.5%) than in control group (due in turn to a significantly greater amount of slow wave sleep (SWS, +14.6%). Similarly, frequency of SWS was greater in exposed group (by 4.9 episodes.h-1). The PS did not differ significantly between the two groups. During the dark period, there were no significant intergroup differences. We conclude that RF-EMF exposure induced a shift in thermal preference towards higher temperatures. The shift in preferred temperature might result from a cold thermal sensation. The change in sleep stage distribution may involve signals from thermoreceptors in the skin. Modulation of SWS may be a protective adaptation in response to RF-EMF exposure.

Exposure to formaldehyde in health care: an evaluation of the white blood count differential.

PubMed

Sancini, Angela; Rosati, Maria Valeria; De Sio, Simone; Casale, Teodorico; Caciari, Tiziana; Samperi, Ilaria; Sacco, Carmina; Fortunato, Bruna Rita; Pimpinella, Benedetta; Andreozzi, Giorgia; Tomei, Gianfranco; Tomei, Francesco

2014-01-01

The aim of our study is to estimate if the occupational exposure to formaldehyde can cause alterations of leukocytes plasma values in health care workers employed in a big hospital compared to a control group. We studied employees in operating rooms and laboratories of Pathological Anatomy, Molecular Biology, Molecular Neurobiology, Parasitology and Experimental Oncology (exposed to formaldehyde) and employees of the Department of Internal Medicine (not exposed). The sample studied was composed of 86 workers exposed to formaldehyde and 86 workers not exposed. All subjects underwent a clinical-anamnaestic examination and for all subjects were measured the following values: total white blood cells, lymphocytes, monocytes and granulocytes (eosinophils, basophils, neutrophils). Statistical analysis of data was based on calculation of the mean, standard deviation and the distribution into classes according to the nature of each variable. Differences were considered significant when p was < 0.05. The mean and the distribution of values of the white blood cells, lymphocytes, monocytes and eosinophils were significantly higher in male subjects exposed to formaldehyde compared to not-exposed. Not significant differences were found in female subjects exposed compared to not exposed. The results underline the importance of a careful risk assessment of workers exposed to formaldehyde and the use of appropriate preventive measures. The health care trained and informed about the risks he is exposed to should observe good standards of behavior and, where it is not possible to use alternative materials, the indoor concentrations of formaldehyde should never exceed occupational limit values.

A review of the effectiveness of stress management skills training on academic vitality and psychological well-being of college students.

PubMed

Alborzkouh, P; Nabati, M; Zainali, M; Abed, Y; Shahgholy Ghahfarokhi, F

2015-01-01

Objective: Carrying out the appropriate psychological interventions to improve vitality and mental well-being is critical. The study was carried out to review the effectiveness of stress management training on the academic life and mental well-being of the students of Shahed University. Methodology: The method used was quasi-experimental with a pretest-posttest plan and control group. Therefore, a total of 40 students of Shahed University of Tehran were selected by a convenience sampling method and were organized into two groups: experimental and control group. Both groups were pretested by using an academic vitality inventory and an 84-question psychological well-being inventory. Then, the experimental group received stress management skills training for ten sessions, and the control group did not receive any intervention. Next, both groups were post-tested, and the data were analyzed with SPSS-21 software by using descriptive and inferential statistical methods. Findings: The findings showed that the stress management skills training significantly contributed to promoting the academic vitality and psychological well-being of students (p < 0.001). Conclusions: It was concluded from this research that teaching the methods for dealing with stress was an effective strategy to help students exposed to high stress and pressure, and this was due to its high efficiency, especially when it was held in groups, had a small cost, and it was accepted by the individuals.

A comparison of the antibacterial activity of the two methods of photodynamic therapy (using diode laser 810 nm and LED lamp 630 nm) against Enterococcus faecalis in extracted human anterior teeth.

PubMed

Asnaashari, Mohammad; Mojahedi, Seyed Masoud; Asadi, Zahra; Azari-Marhabi, Saranaz; Maleki, Alireza

2016-03-01

Failure of endodontic treatment is usually due to an inadequate disinfection of the root canal system. Enterococcus faecalis has been widely used as a valuable microbiological marker for in-vitro studies because of its ability to colonize in a biofilm like style in root canals, invading dentinal tubules and resistance to some endodontic treatments. The aim of this study was to investigate the antibacterial effects of two methods of photodynamic therapy using a light emitting diode lamp (LED lamp, 630 nm) and a diode laser (810 nm) on E. faecalis biofilms in anterior extracted human teeth. Fifty six single-rooted extracted teeth were used in this study. After routine root canal cleansing, shaping and sterilization, the teeth were incubated with E. faecalis for a period of two weeks. Teeth were then divided into two experimental groups (nu=23) and two control groups (nu=5). Teeth in one experimental group were exposed to a diode laser (810 nm), and in the other group samples were exposed to a LED lamp (630 nm). Intracanal bacterial sampling was done, and bacterial survival rate was then evaluated for each group. The Colony Forming Unit (CFU) in LED group (log10 CFUs=4.88±0.82) was significantly lower than the laser group (log CFUs=5.49±0.71) (p value=0.021). CFUs in positive control group (Log10 CFUs=10.96±0.44) were significantly higher than the treatment group (p˂0.001). No bacterial colony was found in negative control group. The results of this research show that photodynamic therapy could be an effective supplement in root canal disinfection. PDT using LED lamp was more effective than diode laser 810 nm in reducing CFUs of E. faecalis in human teeth. Copyright © 2015 Elsevier B.V. All rights reserved.

The influence of the guided constructivist instructional model on attitudes toward secondary-level physics

NASA Astrophysics Data System (ADS)

Dallal, Kamel Salim

The effect of guided constructivism (bridging analogies) and expository instructional methods on the attitudes of students toward physics was investigated. A nonrandomize nonequivalent pretest-posttest control group quasi- experimental design was employed. The sample consisted of 127 eleventh-grade and twelfth-grade students from five selected classes from two private high schools in Beirut, Lebanon. Two intact classes were assigned to the control group and three classes to the experimental group. The experimental group was exposed to the bridging analogies instructional method, and the control group was taught using the traditional expository method. A Likert-type instrument, the Physics Attitude Index, was used to measure attitudes on four dimensions. The 40-item Physics Attitude Index (PAI) is a questionnaire using a five response scale. Performance in the assigned topics in physics, cognitive developmental levels, and gender were used as covariants and to examine interaction effects. The experimental groups had significantly higher means than the control groups on all criterion variables. A significant interaction was found between groups and performance levels in the following cases: (a) criterion variable of attitude toward physics; (b) views toward physics learning; and (c) enjoyment of physics. This result indicated that the low performing students among the experimental group had greater gain in attitude toward physics than the high performing students in same group. On the other hand, no interaction occurred between treatment groups and gender, which shows that in this study gender has no significant effect on attitude toward physics. Significant interactions between the treatment groups and cognitive levels were found on the criterion variable of beliefs about physics as a process of learning and enjoyment of physics. In both cases, the difference between the group means were widely different among students at the concrete and transitional levels, but narrowly different among students at the formal level.

Effects of electromagnetic radiation from 3G mobile phone on heart rate, blood pressure and ECG parameters in rats.

PubMed

Colak, Cengiz; Parlakpinar, Hakan; Ermis, Necip; Tagluk, Mehmet Emin; Colak, Cemil; Sarihan, Ediz; Dilek, Omer Faruk; Turan, Bahadir; Bakir, Sevtap; Acet, Ahmet

2012-08-01

Effects of electromagnetic energy radiated from mobile phones (MPs) on heart is one of the research interests. The current study was designed to investigate the effects of electromagnetic radiation (EMR) from third-generation (3G) MP on the heart rate (HR), blood pressure (BP) and ECG parameters and also to investigate whether exogenous melatonin can exert any protective effect on these parameters. In this study 36 rats were randomized and evenly categorized into 4 groups: group 1 (3G-EMR exposed); group 2 (3G-EMR exposed + melatonin); group 3 (control) and group 4 (control + melatonin). The rats in groups 1 and 2 were exposed to 3G-specific MP's EMR for 20 days (40 min/day; 20 min active (speech position) and 20 min passive (listening position)). Group 2 was also administered with melatonin for 20 days (5 mg/kg daily during the experimental period). ECG signals were recorded from cannulated carotid artery both before and after the experiment, and BP and HR were calculated on 1st, 3rd and 5th min of recordings. ECG signals were processed and statistically evaluated. In our experience, the obtained results did not show significant differences in the BP, HR and ECG parameters among the groups both before and after the experiment. Melatonin, also, did not exhibit any additional effects, neither beneficial nor hazardous, on the heart hemodynamics of rats. Therefore, the strategy (noncontact) of using a 3G MP could be the reason for ineffectiveness; and use of 3G MP, in this perspective, seems to be safer compared to the ones used in close contact with the head. However, further study is needed for standardization of such an assumption.

Effect of a glutathione S-transferase inhibitor on oxidative stress and ischemia-reperfusion-induced apoptotic signalling of cultured cardiomyocytes

PubMed Central

Röth, E; Marczin, N; Balatonyi, B; Ghosh, S; Kovács, V; Alotti, N; Borsiczky, B; Gasz, B

2011-01-01

Oxidative stress and ischemia-reperfusion (I/R) injury are crucial in the pathogenesis of cardiovascular diseases. The antioxidant glutathione S-transferase (GST) is responsible for the high-capacity metabolic inactivation of electrophilic compounds and toxic substrates. The main objective of the present study was to examine the effect of GST inhibition (with the administration of ethacrynic acid [EA]) on the viability and apoptosis of cardiomyocytes when these cells are exposed to various stress components of I/R and mitogen-activated protein kinase (c-Jun N-terminal kinase, p38 and extracellular signal-regulated kinase [ERK]) inhibitors. The primary culture of neonatal rat cardiomyocytes was divided into six experimental groups: control group of cells (group 1), cells exposed to H2O2 (group 2), I/R (group 3), I/R and EA (group 4), H2O2 coupled with EA (group 5), and EA alone (group 6). The viability of cardiomyocytes was determined using a colorimetric MTT assay. The apoptosis ratio was evaluated via fluorescein isothiocyanate-labelled annexin V and propidium iodide staining. c-Jun N-terminal kinase, p38, Akt/protein kinase B and ERK/p42-p44 transcription factors were monitored with flow cytometry. c-Jun N-terminal kinase activation increased due to GST inhibition during I/R. EA administration led to a significant increase in p38 activation following both H2O2 treatment and I/R. ERK phosphorylation increased when GST was exposed to I/R. A pronounced decrease in Akt phosphorylation was observed when cells were cotreated with EA and H2O2. GST plays an important role as a regulator of mitogen-activated protein kinase pathways in I/R injury. PMID:22065940

High sodium intake during postnatal phases induces an increase in arterial blood pressure in adult rats.

PubMed

Moreira, M C S; da Silva, E F; Silveira, L L; de Paiva, Y B; de Castro, C H; Freiria-Oliveira, A H; Rosa, D A; Ferreira, P M; Xavier, C H; Colombari, E; Pedrino, Gustavo R

2014-12-28

Epigenetic studies suggest that diseases that develop in adulthood are related to certain conditions to which the individual is exposed during the initial stages of life. Experimental evidence has demonstrated that offspring born to mothers maintained on high-Na diets during pregnancy have higher mean arterial pressure (MAP) in adulthood. Although these studies have demonstrated the importance of prenatal phases to hypertension development, no evidence regarding the role of high Na intake during postnatal phases in the development of this pathology has been reported. Therefore, in the present study, the effects of Na overload during childhood on induced water and Na intakes and on cardiovascular parameters in adulthood were evaluated. Experiments were carried out in two groups of 21-d-old rats: experimental group, maintained on hypertonic saline (0.3 m-NaCl) solution and food for 60 d, and control group, maintained on tap water and food. Later, both groups were given water and food for 15 d (recovery period). After the recovery period, chronic cannulation of the right femoral artery was performed in unanaesthetised rats to record baseline MAP and heart rate (HR). The experimental group was found to have increased basal MAP (98.6 (sem 2.6) v. 118.3 (sem 2.7) mmHg, P< 0.05) and HR (365.4 (sem 12.2) v. 398.2 (sem 7.5) beats per min, P< 0.05). There was a decrease in the baroreflex index in the experimental group when compared with that in the control group. A water and Na intake test was performed using furosemide. Na depletion was found to induce an increase in Na intake in both the control and experimental groups (12.1 (sem 0.6) ml and 7.8 (sem 1.1), respectively, P< 0.05); however, this increase was of lower magnitude in the experimental group. These results demonstrate that postnatal Na overload alters behavioural and cardiovascular regulation in adulthood.

Examination of the antioxidant effects of pre-HSG melatonin use on ovarian surface epithelium in rats: An experimental study.

PubMed

Yılmaz, Esra Saygılı; Sapmaz, Tansel; Kazgan, Halil; Yildiz, Şule Menziletoglu; Kocamaz, Derya; Akpolat, Nusret; Sapmaz, Ekrem

2018-06-28

There is no study of whether the dysplastic changes in the ovarian surface epithelium of X-ray-exposed rats during hysterosalpingography (HSG) decrease or not with the use of Lipiodol and melatonin given both intraperitoneally (i.p.) and into the suspensorium ovarii. We investigated the restorative effects of melatonin and Lipiodol administration during the HSG procedure on the dysplastic changes in the ovarian surface epithelium of X-ray-exposed rats. A total of 50 Wistar rats with regular estrous cycles were randomly divided into 5 groups. Group 1 was the control group. In other groups, X-ray was applied (group 2), 0.1 mL Lipiodol was applied to each uterine horn (group 3), 20 mg/kg intraperitoneal melatonin application was followed by 0.1 mL Lipiodol administration to each uterine horn after 15 min (group 4), and 20 mg/kg melatonin was administered to the ligamentum suspensorium ovarii, followed by 0.1 mL Lipiodol application to each uterine horn after 15 min (group 5). The rats in groups 2-5 were exposed to whole body radiation 3 times. After 3 h, the abdomens of all rats were reopened and left oophorectomy was performed. The presence of nucleoli and mitosis values were found similar among the groups. All other parameters were significantly higher in group 2 compared to other groups, except for the presence of nucleoli and mitosis values (p < 0.05). The presence of hyperchromasia and the total score were found to be the highest in group 2, followed by group 3, when compared to other groups (p < 0.05). It was detected that the detrimental effects of X-ray exposure diminished with Lipiodol use, and were further reduced by the use of melatonin in combination. We suggest that the use of melatonin and Lipiodol during HSG may prevent the carcinogenic changes exerted by radiation on the ovarian surface epithelium.

Comparison of in vivo dental pulp responses to capping with iRoot BP Plus and mineral trioxide aggregate.

PubMed

Shi, S; Bao, Z F; Liu, Y; Zhang, D D; Chen, X; Jiang, L M; Zhong, M

2016-02-01

To compare dental pulp responses to capping with iRoot BP Plus and mineral trioxide aggregate (MTA) in dogs. Pulps in 36 incisors of three 8-month-old beagle dogs were mechanically exposed and assigned to two experimental groups (iRoot BP Plus group and MTA group, n = 15 per group) and one control group (n = 6). Direct pulp capping was performed using either iRoot BP Plus or MTA. The animals were sacrificed 3 months later. Histological sections were stained with haematoxylin and eosin and categorized using a histologic scoring system. Statistical analysis was performed using the Mann-Whitney U-test, with the significance set at 0.05. The majority of specimens in both experimental groups were associated with complete calcified bridge formation and the absence of pulpal inflammation. There was no significant difference in pulp response to iRoot BP Plus or MTA after 3 months (P > 0.05). iRoot BP Plus and MTA had similar favourable results when used as pulp-capping agents. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harrison, F.L.; Anderson, S.L.

The effects of lifetime exposure to chronic irradiation on reproductive success were assessed for laboratory populations of the polychaete worm Neanthes arenaceodentata. Lifetime exposure was initiated upon the spawning of the P1 female and was terminated upon spawning of the F1 female. Groups of experimental worms received either no radiation (controls) or 0.19, 2.1, or 17 mGy/h. The total dose received by the worms was either background or approximately 0.55, 6.5, or 54 Gy, respectively. The broods from the F1 mated pairs were sacrificed before hatching occurred, and information was obtained on brood size, on the number of normal andmore » abnormal embryos, and on the number of embryos that were living, dying, and dead. The mean number of embryos in the broods from the F1 females exposed to lifetime radiation of 0.19 and 2.1 mGy/h was not significantly different from the mean number of embryos from control females; however, the mean number of embryos was different from those F1 females exposed to 17 mGy/h. There was a significant reduction in the number of live embryos in the broods from the F1 mated pairs that were exposed to the lowest dose rate given, 0.19 mGy/h, as well as those exposed to 2.1 and 17 mGy/h. Also, increased percentages of abnormal embryos were determined in the broods of all the radiation-exposed groups. 39 refs., 10 figs., 15 tabs.« less

Consequences of Learned Helplessness and Recognition of the State of Cognitive Exhaustion in Persons with Mild Intellectual Disability

PubMed Central

Gacek, Michał; Smoleń, Tomasz; Pilecka, Władysława

2017-01-01

Persons with intellectual disability are a group at risk of being exposed to overly demanding problem-solving situations, which may produce learned helplessness. The research was based on the informational model of learned helplessness. The consequences of exposure to an unsolvable task and the ability to recognize the symptoms of cognitive exhaustion were tested in 120 students with mild intellectual disability. After the exposure to the unsolvable task, persons in the experimental group obtained lower results than the control group in the escape/avoidance learning task, but a similar result was found in the divergent thinking fluency task. Also, participants in the experimental group had difficulties recognizing the symptoms of the cognitive exhaustion state. After a week’s time, the difference in escape/avoidance learning performance was still observed. The results indicate that exposure to unsolvable tasks may negatively influence the cognitive performance in persons with intellectual disability, although those persons may not identify the cognitive state related to lowered performance. PMID:28479937

Consequences of Learned Helplessness and Recognition of the State of Cognitive Exhaustion in Persons with Mild Intellectual Disability.

PubMed

Gacek, Michał; Smoleń, Tomasz; Pilecka, Władysława

2017-01-01

Persons with intellectual disability are a group at risk of being exposed to overly demanding problem-solving situations, which may produce learned helplessness . The research was based on the informational model of learned helplessness. The consequences of exposure to an unsolvable task and the ability to recognize the symptoms of cognitive exhaustion were tested in 120 students with mild intellectual disability. After the exposure to the unsolvable task, persons in the experimental group obtained lower results than the control group in the escape/avoidance learning task, but a similar result was found in the divergent thinking fluency task. Also, participants in the experimental group had difficulties recognizing the symptoms of the cognitive exhaustion state. After a week's time, the difference in escape/avoidance learning performance was still observed. The results indicate that exposure to unsolvable tasks may negatively influence the cognitive performance in persons with intellectual disability, although those persons may not identify the cognitive state related to lowered performance.

No adverse effects detected for simultaneous whole-body exposure to multiple-frequency radiofrequency electromagnetic fields for rats in the intrauterine and pre- and post-weaning periods.

PubMed

Shirai, Tomoyuki; Wang, Jianqing; Kawabe, Mayumi; Wake, Kanako; Watanabe, So-Ichi; Takahashi, Satoru; Fujiwara, Osamu

2017-01-01

In everyday life, people are exposed to radiofrequency (RF) electromagnetic fields (EMFs) with multiple frequencies. To evaluate the possible adverse effects of multifrequency RF EMFs, we performed an experiment in which pregnant rats and their delivered offspring were simultaneously exposed to eight different communication signal EMFs (two of 800 MHz band, two of 2 GHz band, one of 2.4 GHz band, two of 2.5 GHz band and one of 5.2 GHz band). Thirty six pregnant Sprague-Dawley (SD) 10-week-old rats were divided into three groups of 12 rats: one control (sham exposure) group and two experimental (low- and high-level RF EMF exposure) groups. The whole body of the mother rats was exposed to the RF EMFs for 20 h per day from Gestational Day 7 to weaning, and F 1 offspring rats (46-48 F1 pups per group) were then exposed up to 6 weeks of age also for 20 h per day. The parameters evaluated included the growth, gestational condition and organ weights of the dams; the survival rates, development, growth, physical and functional development, memory function, and reproductive ability of the F 1 offspring; and the embryotoxicity and teratogenicity in the F 2 rats. No abnormal findings were observed in the dams or F 1 offspring exposed to the RF EMFs or to the F 2 offspring for any of the parameters evaluated. Thus, under the conditions of the present experiment, simultaneous whole-body exposure to eight different communication signal EMFs at frequencies between 800 MHz and 5.2 GHz did not show any adverse effects on pregnancy or on the development of rats. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

The influence of pressure changes on the retentive force and coronal microleakage of different types of posts in endodontically treated teeth during simulated dives.

PubMed

Mitov, Gergo; Draenert, Florian; Schumann, Paul; Stötzer, Marcus; von See, Constantin

2016-12-01

We assessed the influence of a simulated diving environment on the interfacial microleakage and retentive forces of different post types in root-canal-filled teeth. One-hundred-and-twenty extracted, single-rooted teeth were endodontically treated and were randomly divided into three groups according to the post and cement used: ER Post/Harvard cement (Titanium), CeraPost/DentinBuild Evo (Zirconia), DT Light Post/Calibra (FRC). Each group was randomly divided into two equal subgroups, a control group, and an experimental group, subjected to simulated dives to 456 kPa in a diving chamber. For 10 specimens of each subgroup the pull-out strength and the coronal microleakage were measured. Significant differences in the linear coronal penetration were observed between the Titanium and FRC groups (experimental group P ≤ 0.001; control group P = 0.02). Diving simulation had no significant impact on the microleakage for the three post types. The FRC groups showed significantly higher retentive strength values compared to the Titanium and Zirconia groups before and after simulated diving. The pull-out strength of the titanium experimental group was significantly less than the control group (P = 0.008). Following root canal treatment the combination of fibre-reinforced posts and resin cement should be preferred for patients requiring retention for tooth restorations using posts that are likely to be exposed to hyperbaric conditions.

Time-course effects of aerobic physical training in the prevention of cigarette smoke-induced COPD.

PubMed

Toledo-Arruda, Alessandra C; Vieira, Rodolfo P; Guarnier, Flávia A; Suehiro, Camila L; Caleman-Neto, Agostinho; Olivo, Clarice R; Arantes, Petra M M; Almeida, Francine M; Lopes, Fernanda D T Q S; Ramos, Ercy M C; Cecchini, Rubens; Lin, Chin Jia; Martins, Milton Arruda

2017-09-01

A previous study by our group showed that regular exercise training (ET) attenuated pulmonary injury in an experimental model of chronic exposure to cigarette smoke (CS) in mice, but the time-course effects of the mechanisms involved in this protection remain poorly understood. We evaluated the temporal effects of regular ET in an experimental model of chronic CS exposure. Male C57BL/6 mice were divided into four groups: Control (sedentary + air), Exercise (aerobic training + air), Smoke (sedentary + smoke), and Smoke + Exercise (aerobic training + smoke). Mice were exposed to CS and ET for 4, 8, or 12 wk. Exercise protected mice exposed to CS from emphysema and reductions in tissue damping and tissue elastance after 12 wk ( P < 0.01). The total number of inflammatory cells in the bronchoalveolar lavage increased in the Smoke group, mainly due to the recruitment of macrophages after 4 wk, neutrophils and lymphocytes after 8 wk, and lymphocytes and macrophages after 12 wk ( P < 0.01). Exercise attenuated this increase in mice exposed to CS. The protection conferred by exercise was mainly observed after exercise adaptation. Exercise increased IL-6 and IL-10 in the quadriceps and lungs ( P < 0.05) after 12 wk. Total antioxidant capacity and SOD was increased and TNF-α and oxidants decreased in lungs of mice exposed to CS after 12 wk ( P < 0.05). The protective effects of exercise against lung injury induced by cigarette smoke exposure suggests that anti-inflammatory mediators and antioxidant enzymes play important roles in chronic obstructive pulmonary disease development mainly after the exercise adaptation. NEW & NOTEWORTHY These experiments investigated for the first time the temporal effects of regular moderate exercise training in cigarette smoke-induced chronic obstructive pulmonary disease. We demonstrate that aerobic conditioning had a protective effect in emphysema development induced by cigarette smoke exposure. This effect was most likely secondary to an effect of exercise on oxidant-antioxidant balance and anti-inflammatory mediators. Copyright © 2017 the American Physiological Society.

Schistosoma haematobium infection in the opossum (Didelphis marsupialis): involvement of the urogenital system.

PubMed

Kuntz, R E; Myers, B J; Cheever, A W

1971-01-01

Investigations of experimental schistosomiasis haematobia have suffered for want of satisfactory mammals in which schistosome infections would establish host-parasite situations more or less comparable with those seen in man. As a consequence, mammals representing different major groups have been exposed to infection by Schistosoma haematobium (Iran strain) to determine their potential use as models for more detailed investigations. In preliminary studies, 8 American opossums (Didelphis marsupialis) were exposed to 1000 or 2000 cercariae. Macroscopic involvement of the urogenital tract was noted in 3 animals, one of which had a 1-cm fibrous plaque in the bladder. In another animal, multiple transitional cell papillomas were present in the bladder and in one ureter.

[Influence of low frequency magnetic field used in magnetotherapy on interleukin 6 (IL-6) contents in rat heart and brain].

PubMed

Ciejka, Elżbieta; Skibska, Beata; Gorąca, Anna

2017-06-27

The human population is exposed ever more frequently to magnetic fields (MF). This is due to both technological progress and development of the economy as well as to advances made in medical science. That is why the thorough understanding and systematized knowledge about mechanisms by which MF exerts its effects on living organisms play such an important role. In this context the health of MF-exposed people is the subject of particular concern. The aim of the study was to evaluate the effect of extremely low frequency magnetic field (ELFMF) used in magnetotherapy on the concentration of interleukin 6 (IL-6) in rat heart and brain. The male rats were randomly divided into 3 experimental groups: group I - control, without contact with magnetic field; group II - exposed to bipolar, rectangular magnetic field 40 Hz, induction "peak-to-peak" 7 mT 30 min/day for 2 weeks; and group III - exposed to bipolar, rectangular magnetic field 40 Hz, 7 mT 60 min/day for 2 weeks. Concentration of IL-6 in the heart and brain of animals was measured after MF exposure. Exposure to ELFMF: 40 Hz, induction "peak-to-peak" 7 mT 30 min/day for 2 weeks caused a significant IL-6 increase in rat hearts compared to the control group (p < 0.05) and a non-significant IL-6 decrease in rat brain. The magnetic field applied for 60 min resulted in non-significant IL-6 increase in rat hearts compared to the control group and significant IL-6 decrease in rat brain (p < 0.05). The influence of magnetic field on inflammation in the body varies depending on the MF parameters and the affected tissues or cells. Med Pr 2017;68(4):517-523. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Removal of the blue component of light significantly decreases retinal damage after high intensity exposure.

PubMed

Vicente-Tejedor, Javier; Marchena, Miguel; Ramírez, Laura; García-Ayuso, Diego; Gómez-Vicente, Violeta; Sánchez-Ramos, Celia; de la Villa, Pedro; Germain, Francisco

2018-01-01

Light causes damage to the retina (phototoxicity) and decreases photoreceptor responses to light. The most harmful component of visible light is the blue wavelength (400-500 nm). Different filters have been tested, but so far all of them allow passing a lot of this wavelength (70%). The aim of this work has been to prove that a filter that removes 94% of the blue component may protect the function and morphology of the retina significantly. Three experimental groups were designed. The first group was unexposed to light, the second one was exposed and the third one was exposed and protected by a blue-blocking filter. Light damage was induced in young albino mice (p30) by exposing them to white light of high intensity (5,000 lux) continuously for 7 days. Short wavelength light filters were used for light protection. The blue component was removed (94%) from the light source by our filter. Electroretinographical recordings were performed before and after light damage. Changes in retinal structure were studied using immunohistochemistry, and TUNEL labeling. Also, cells in the outer nuclear layer were counted and compared among the three different groups. Functional visual responses were significantly more conserved in protected animals (with the blue-blocking filter) than in unprotected animals. Also, retinal structure was better kept and photoreceptor survival was greater in protected animals, these differences were significant in central areas of the retina. Still, functional and morphological responses were significantly lower in protected than in unexposed groups. In conclusion, this blue-blocking filter decreases significantly photoreceptor damage after exposure to high intensity light. Actually, our eyes are exposed for a very long time to high levels of blue light (screens, artificial light LED, neons…). The potential damage caused by blue light can be palliated.

Comparison of Light Emitting Diodes (LED) and Fluorescent Light on Suppression of Pineal Melatonin in the Rat

NASA Technical Reports Server (NTRS)

Winget, Charles M.; Heeke, D. S.; Holley, D. C.; Mele, G.; Brainard, G. C.; Hanifin, J. P.; Rollag, M. D.; Savage, Paul D. (Technical Monitor)

1997-01-01

To validate a novel LED array for use in animal habitat lighting by comparing its effectiveness to cool-white fluorescent (CWF) lighting in suppressing pineal gland melatonin. Male Sprague-Dawley rats, 175-200 g, were maintained under control conditions for 2 weeks (food and water ad lib, 12L: 12D CWF, 18 uW/square cm). Dark adapted animals (animals before lights on) were exposed to 5 min of LED or CWF light of similar spectral power distribution. Two groups of rats (LED vs. CWF) were compared at 5 light intensities (100, 40, 1, 1.0, and 0. 1 lux). A control group was placed into the exposure apparatus but not exposed to light. After exposure, pineal glands were rapidly removed and assayed for melatonin by RIA. Results. The dark-exposed control groups matched with the 5 intensity groups (100, 40, 10, 1.0, and 0.1 lux) showed mean + SEM pineal melatonin values of 1167 +/- 136, 1569 +/- 126, 353 +/- 34, 650 +/- 124, and 464 +/- 85, pg/ml respectively. The corresponding CWF exposure data were 393 1 41, 365 +34, 257 +/- 13, 218 +/- 42, and 239 +/- 71 pg/ml, respectively. Corresponding LED exposure data were 439 +/- 25, 462 +/- 50, 231 +/- 6, 164 +/- 12, and 158 +/- 12 pg/ml, respectively. Rats exposed to both experimental light conditions at all illuminances studied showed significant melatonin suppression (p less than 0.01, ANOVA). In no case was the melatonin suppression induced by LED illuminance significantly different from the melatonin suppression elicited by the same intensity of CWF light. The results show that a novel LED light source can suppress pineal melatonin equal to that of a conventional CWF light source.

Histopathological changes in Wistar albino rats exposed to aqueous extract of unripe Carica papaya.

PubMed

Oduola, Taofeeq; Bello, Ibrahim; Idowu, Thomas; Avwioro, Godwin; Adeosun, Ganiyu; Olatubosun, Luqman

2010-05-01

Exposure of animals to xenobiotics may or may not trigger adverse response at cellular levels. Aqueous extract of unripe Carica papaya is consumed by sickle cell patients as antisickling agent in Western Nigeria. This study was undertaken to investigate the effects of Carica papaya on certain organs in Wister albino rats exposed to aqueous extract of unripe Carica papaya. Different doses of aqueous extract of unripe Carica papaya were administered orally daily for 42 days to six groups of rats. At the end of exposure, the animals were sacrificed and tissue sections were prepared from livers, kidneys, hearts and small intestines using standard techniques. Histopathological results showed that no pathological changes were observed in tissue sections of experimental animals when compared with tissue sections of the same organs in control animals. No pathological changes were elicited in the organs of rats exposed to aqueous extract of unripe Carica papaya.

The impact of aircraft noise exposure on South African children's reading comprehension: the moderating effect of home language.

PubMed

Seabi, Joseph; Cockcroft, Kate; Goldschagg, Paul; Greyling, Mike

2012-01-01

Given the limited studies conducted within the African continent, the purpose of this study was to investigate the impact of chronic aircraft noise exposure and the moderating effect of home language on the learners' reading comprehension. The sample comprised 437 (52%) senior primary learners exposed to high levels of aircraft noise (Experimental group) and 337 (48%) learners residing in a quieter area (Control group). Of these, 151 learners in the Experimental group spoke English as a first language (EFL) and 162 spoke English as a second language (ESL). In the Control group, the numbers were similarly divided (EFL n = 191; ESL n = 156). A univariate General Linear Model was used to investigate the effects of aircraft noise exposure and language on reading comprehension, while observing for the possible impact of intellectual ability, gender, and socioeconomic status on the results. A significant difference was observed between ESL and EFL learners in favor of the latter (F 1,419 = 21.95, P =.000). In addition a substantial and significant interaction effect was found between the experimental and control groups for the two language groups. For the EFL speakers there was a strong reduction in reading comprehension in the aircraft noise group. By contrast this difference was not significant for the ESL speakers. Implications of the findings and suggestions for further research are made in the article.

The effect of thought importance on stress responses: a test of the metacognitive model.

PubMed

Capobianco, Lora; Morrison, Anthony P; Wells, Adrian

2018-03-01

Negative metacognitive beliefs are central determinants of distress in the metacognitive model of psychological vulnerability to stress. The current study tested this assertion in 75 undergraduate students assigned to either experimental (metacognitive belief manipulation) or control (no metacognitive belief manipulation) condition. All participants underwent a fake EEG, where they were told that the EEG would detect negative thoughts. The experimental subjects were informed that if they had a negative thought they may be exposed to a contingent burst of loud noise, while the control condition was told that they may be exposed to a burst of loud noise at random. Participants also underwent the Trier Social Stress Test. The results showed that on physiological measures (skin conductance level) there were no significant differences between groups. However, on self-report measures (positive and negative affect) participants in the experimental condition reported greater levels of negative affect and lower levels of positive affect in response to stress and maintained low positive affect at recovery. The results are consistent with the metacognitive model and suggest that metacognitive beliefs impact on positive and negative affect in reaction to and recovery from stress exposure.

[Effect of overdose fluoride on expression of bone sialoprotein in developing dental tissues of rats].

PubMed

Xu, Zhi-ling; Wang, Qiang; Liu, Tian-lin; Guo, Li-ying; Jing, Feng-qiu; Liu, Hui

2006-04-01

To investigate the changes of bone sialoprotein (BSP) in developing dental tissues of rats exposed to fluoride. Twenty rats were randomly divided into two groups, one was with distilled water (control group), the other was with distilled water treated by fluoride (experimental group). When the fluorosis model was established, the changes of the expression of BSP were investigated and compared between the two groups. HE staining was used to observe the morphology of the cell, and immunohistochemisty assay was used to determine the expression of BSP in rat incisor. Student's t test was used for statistical analysis. The ameloblasts had normal morphology and arranged orderly. Immunoreactivitis of BSP was present in matured ameloblasts, dentinoblasts, cementoblasts, and the matrix in the control group. But in the experimental group the ameloblasts arranged in multiple layers, the enamel matrix was confused and the expression of BSP was significantly lower than that of the control group. Statistical analysis showed significant differences between the two groups (P<0.01). Fluoride can inhibit the expression of BSP in developing dental tissues of rats, and then inhibit differentiation of the tooth epithelial cells and secretion of matrix. This is a probable intracellular mechanism of dental fluorosis.

Vision in Sight: The Relationships between Knowledge, Health Beliefs and Treatment Outcomes. The Case of Amblyopia. Linkoping Studies in Education and Psychology, Dissertation No. 65.

ERIC Educational Resources Information Center

Goransson, Anne

The research reported is an experimental study on the effects of intensified education of Swedish parents of children with amblyopia (dimness of sight without apparent organic defect) on their understanding of the nature of the disease, its origins, and treatment. Parents in the control group (n=60) were exposed to the ordinary information…

Chemoprevention of Prostate Cancer by Phenethyl Isothiocyanate

DTIC Science & Technology

2007-03-01

AD cells were exposed to PEITC, protein synthesis inhibitor cycloheximide (CHX), or proteasome inhibitor MG-132 alone, or to the combination of...The results indicated that down-regulation of Sp1 may require protein synthesis for a proteasome activity, thereby enhancing Sp1 protein degradation...carcinogen N- methyl-N- nitrosourea (MNU) for the formation of prostate tumors. The experimental group of rats was provided with PEITC, to evaluate the

Skin decontamination efficacy of potassium ketoxime on rabbits exposed to sulfur mustard.

PubMed

Sun, Jing-Hai; Sun, Pei-Pei; Zheng, Wei; Han, Song; Ying, Ying; Liu, Hong-Yan; Zhang, Cheng; Zhao, Bao-Quan; Zuo, Guo-Min; Lu, Hong; Zhong, Yu-Xu

2015-03-01

The chemical weapon sulfur mustard (SM) is a blister agent, and currently, there is no effective antidote. To evaluate the decontamination efficacy of potassium ketoxime against SM and preliminarily elucidate its decontamination mechanism. Potassium ketoxime reacted with SM, and SM residues were tested at different time intervals by T-135 colorimetry after the reaction. Rabbit skin was topically exposed to 2 mg/cm(2) SM, treated with potassium ketoxime 1 min later, and observed after 6, 12, and 24 h. Gas chromatography-mass spectroscopy was employed to screen and identify the main products of potassium ketoxime decontamination of SM. Potassium ketoxime had a great effect against SM contamination. With a mass ratio of decontaminant: SM of 50:1, decontamination rates against SM were 87.5% after 30 s, 95.9% after 1 min, and 99.0% after 5 min. Fifteen minutes after exposure to SM, the untreated group showed clear erythema lesions, whereas the experimental group showed no clear erythema lesions within 6 h. After 12 and 24 h, the areas of damaged skin in the experimental group were 0.038 and 0.125 cm(2), respectively, compared with 2.21 and 2.65 cm(2) in the control group. Histopathological analysis revealed that treatment with potassium ketoxime also reduced inflammation-induced damage. The results of this study indicate that potassium ketoxime reacted rapidly and completely with SM, and thus, it was found to be a suitable and effective skin decontaminant against SM. The decontamination reaction mechanism is mainly related to nucleophilic substitution.

Statistical analysis of nonmonotonic dose-response relationships: research design and analysis of nasal cell proliferation in rats exposed to formaldehyde.

PubMed

Gaylor, David W; Lutz, Werner K; Conolly, Rory B

2004-01-01

Statistical analyses of nonmonotonic dose-response curves are proposed, experimental designs to detect low-dose effects of J-shaped curves are suggested, and sample sizes are provided. For quantal data such as cancer incidence rates, much larger numbers of animals are required than for continuous data such as biomarker measurements. For example, 155 animals per dose group are required to have at least an 80% chance of detecting a decrease from a 20% incidence in controls to an incidence of 10% at a low dose. For a continuous measurement, only 14 animals per group are required to have at least an 80% chance of detecting a change of the mean by one standard deviation of the control group. Experimental designs based on three dose groups plus controls are discussed to detect nonmonotonicity or to estimate the zero equivalent dose (ZED), i.e., the dose that produces a response equal to the average response in the controls. Cell proliferation data in the nasal respiratory epithelium of rats exposed to formaldehyde by inhalation are used to illustrate the statistical procedures. Statistically significant departures from a monotonic dose response were obtained for time-weighted average labeling indices with an estimated ZED at a formaldehyde dose of 5.4 ppm, with a lower 95% confidence limit of 2.7 ppm. It is concluded that demonstration of a statistically significant bi-phasic dose-response curve, together with estimation of the resulting ZED, could serve as a point-of departure in establishing a reference dose for low-dose risk assessment.

Chronic perchlorate exposure impairs stickleback reproductive behaviour and swimming performance

PubMed Central

Bernhardt, Richard R.; von Hippel, Frank A.

2011-01-01

Summary We describe behavioural changes in two generations of threespine stickleback (Gasterosteus aculeatus) exposed to environmentally relevant concentrations of perchlorate. The first generation (G0,2002) was exposed as two-year-old adults to perchlorate in experimental groups ranging in concentration from less than the method detection limit (<1.1 ppb) to 18.6 ppm for up to 22 days during their courtship, spawning, egg guarding, and first five days of fry guarding. No differences were noted in the behaviour or reproductive output of these fish that were exposed as adults. However, perchlorate exposure throughout development caused widespread effects in the second generation (G1,2003), which was spawned and raised through sexual maturity in one of four nominal experimental groups (0, 30 and 100 ppm, and a ‘variable’ treatment that progressively increased from <1.1 ppb to approximately 60 ppm perchlorate). Dose-dependent effects were found during the G1,2003’s swimming and behavioural evaluations, including higher mortality rates among treated fish following stressful events. Perchlorate-exposed fish had higher failure rates during swimming trials and failed at lower flow rates than control fish. A number of treated fish exhibited seizures. Progressively fewer males completed benchmark metrics, such as nest building, spawning, nursery formation, or fry production, in a dose-dependent manner. Fewer males from higher treatments courted females, and those that did initiated courtship later and had a reduced behavioural repertoire compared to fish from lower treatments. The lowest observed adverse effect level (LOAEL) for swimming performance, reproductive behaviour, survivorship and recruitment was 30 ppm perchlorate (our lowest G1,2003 treatment), and near complete inhibition of reproductive activity was noted among males raised in 100 ppm perchlorate. A small number of treated G1,2003 females were isolated in aquaria, and some performed reproductive behaviour typical of males, such as biting, leading and zig-zagging in the presence of gravid females. These findings have profound implications for recruitment in wild fish populations exposed to perchlorate, and suggest that perchlorate may disrupt behaviour in other vertebrates as well. PMID:22228909

Prenatal Drug Exposure and Adolescent Cortisol Reactivity: Association with Behavioral Concerns.

PubMed

Buckingham-Howes, Stacy; Mazza, Dayna; Wang, Yan; Granger, Douglas A; Black, Maureen M

2016-09-01

To examine stress reactivity in a sample of adolescents with prenatal drug exposure (PDE) by examining the consequences of PDE on stress-related adrenocortical reactivity, behavioral problems, and drug experimentation during adolescence. Participants (76 PDE, 61 non-drug exposed [NE]; 99% African-American; 50% male; mean age = 14.17 yr, SD = 1.17) provided a urine sample, completed a drug use questionnaire, and provided saliva samples (later assayed for cortisol) before and after a mild laboratory stress task. Caregivers completed the Behavior Assessment System for Children, Second Edition (BASC II) and reported their relationship to the adolescent. The NE group was more likely to exhibit task-related cortisol reactivity compared to the PDE group. Overall behavior problems and drug experimentation were comparable across groups with no differences between PDE and NE groups. In unadjusted mediation analyses, cortisol reactivity mediated the association between PDE and BASC II aggression scores (95% bootstrap confidence interval [CI], 0.04-4.28), externalizing problems scores (95% bootstrap CI, 0.03-4.50), and drug experimentation (95% bootstrap CI, 0.001-0.54). The associations remain with the inclusion of gender as a covariate but not when age is included. Findings support and expand current research in cortisol reactivity and PDE by demonstrating that cortisol reactivity attenuates the association between PDE and behavioral problems (aggression) and drug experimentation. If replicated, PDE may have long-lasting effects on stress-sensitive physiological mechanisms associated with behavioral problems (aggression) and drug experimentation in adolescence.

[Coenzyme Q10 enhances the expression of Bcl-2 and inhibits the expressions of Bax and GSK-3β in the hippocampus of rats exposed to ischemia/reperfusion injury].

PubMed

Tian, Shuang; Wang, Di; Li, Xiaodong; Tang, Jianjie; Han, Guang; Dai, Yongyi

2013-07-01

To investigate the effects of coenzyme Q10 pretreatment on the expressions of Bcl-2, Bax and glycogen synthase kinase-3β (GSK-3β) in rats suffering from ischemia/reperfusion injury. Thirty-six adult male SD rats were randomly assigned into 3 groups: sham-operated group (sham), ischemia/reperfusion group (I/R) and coenzyme Q10 preconditioning group (Q10). Focal cerebral ischemia/reperfusion models were established in experimental rats by blocking middle cerebral artery with suture. Histological changes of hippocampal neurons were observed by HE staining. The expressions of Bcl-2, Bax and GSK-3β were detected by immunohistochemistry and Western blotting. Immunohistochemistry showed that the percentage of Bcl-2 positive cells increased in the hippocampus, while the percentages of Bax and GSK-3β positive cells decreased in Q10 group compared with I/R group. Western blotting revealed that the expression level of Bcl-2 was higher and the expression levels of Bax and GSK-3β were lower in Q10 group than in I/R group. There were significant differences between the two groups (P<0.05). Coenzyme Q10 promoted the expression of Bcl-2 and suppressed the expressions of Bax and GSK-3β in the hippocampus of rats exposed to cerebral ischemia/reperfusion.

Effects of simulated microgravity on the development of the swimbladder and buoyancy control in larval zebrafish (Danio rerio).

PubMed

Lindsey, Benjamin W; Dumbarton, Tristan C; Moorman, Stephen J; Smith, Frank M; Croll, Roger P

2011-06-01

The gas-filled swimbladder of teleost fishes provides hydrodynamic lift which counteracts the high density of other body tissues, and thereby allows the fish to achieve neutral buoyancy with minimal energy expenditure. In this study, we examined whether the absence of a constant direction gravitational vector affects the ontogeny of the swimbladder and buoyancy control in zebrafish (Danio rerio). We exposed fertilized eggs to simulated microgravity (SMG) in a closed rotating wall vessel with control eggs placed in a similar but nonrotating container. All eggs hatched in both groups. At 96 hr of postfertilization (hpf), all larvae were removed from the experimental and control vessels. At this point, 62% of the control larvae, but only 14% of SMG-exposed larvae, were observed to have inflated their swimbladder. In addition, the mean volume of the inflated swimbladders was significantly greater in the control larvae compared with larvae raised in SMG. After transfer to open stationary observation tanks, larvae with uninflated swimbladders in both groups swam to the surface to complete inflation, but this process was significantly delayed in larvae exposed to SMG. Initial differences in swimbladder inflation and volume between groups disappeared by 144 hpf. Furthermore, there were no apparent changes in patterns of development and maturation of swimbladder musculature, vasculature, or innervation resulting from SMG exposure at later stages of ontogeny. These data indicate that, despite a transient delay in swimbladder inflation in zebrafish larvae exposed to SMG, subsequent swimbladder development in these animals proceeded similarly to that in normal larvae. Copyright © 2011 Wiley-Liss, Inc., A Wiley Company.

Genetic and Pathological Follow-Up Study of Goats Experimentally and Naturally Exposed to a Sheep Scrapie Isolate.

PubMed

Maestrale, Caterina; Cancedda, Maria G; Pintus, Davide; Masia, Mariangela; Nonno, Romolo; Ru, Giuseppe; Carta, Antonello; Demontis, Francesca; Santucciu, Cinzia; Ligios, Ciriaco

2015-10-01

Thirty-seven goats carrying different prion protein genotypes (PRNP) were orally infected with a classical scrapie brain homogenate from wild-type (ARQ/ARQ) sheep and then mated to obtain 2 additional generations of offspring, which were kept in the same environment and allowed to be naturally exposed to scrapie. Occurrence of clinical or subclinical scrapie was observed in the experimentally infected goats (F0) and in only one (F1b) of the naturally exposed offspring groups. In both groups (F0 and F1b), goats carrying the R154H, H154H, R211Q, and P168Q-P240P dimorphisms died of scrapie after a longer incubation period than wild-type, G37V, Q168Q-P240P, and S240P goats. In contrast, D145D and Q222K goats were resistant to infection. The immunobiochemical signature of the scrapie isolate and its pathological aspects observed in the sheep donors were substantially maintained over 2 goat generations, i.e., after experimental and natural transmission. This demonstrates that the prion protein gene sequence, which is shared by sheep and goats, is more powerful than any possible but unknown species-related factors in determining scrapie phenotypes. With regard to genetics, our study confirms that the K222 mutation protects goats even against ovine scrapie isolates, and for the first time, a possible association of D145 mutation with scrapie resistance is shown. In addition, it is possible that the sole diverse frequencies of these genetic variants might, at least in part, shape the prevalence of scrapie among naturally exposed progenies in affected herds. This study was aimed at investigating the genetic and pathological features characterizing sheep-to-goat transmission of scrapie. We show that in goats with different prion protein gene mutations, the K222 genetic variant is associated with scrapie resistance after natural and experimental exposure to ovine prion infectivity. In addition, we observed for the first time a protective effect of the D145 goat variant against scrapie. Importantly, our results demonstrate that the phenotypic characteristic of the wild-type sheep scrapie isolate is substantially preserved in goats carrying different susceptible PRNP gene variants, thus indicating that the prion protein gene sequence, which is shared by sheep and goats, plays a fundamental role in determining scrapie phenotypes. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Genetic and Pathological Follow-Up Study of Goats Experimentally and Naturally Exposed to a Sheep Scrapie Isolate

PubMed Central

Maestrale, Caterina; Cancedda, Maria G.; Pintus, Davide; Masia, Mariangela; Nonno, Romolo; Ru, Giuseppe; Carta, Antonello; Demontis, Francesca; Santucciu, Cinzia

2015-01-01

ABSTRACT Thirty-seven goats carrying different prion protein genotypes (PRNP) were orally infected with a classical scrapie brain homogenate from wild-type (ARQ/ARQ) sheep and then mated to obtain 2 additional generations of offspring, which were kept in the same environment and allowed to be naturally exposed to scrapie. Occurrence of clinical or subclinical scrapie was observed in the experimentally infected goats (F0) and in only one (F1b) of the naturally exposed offspring groups. In both groups (F0 and F1b), goats carrying the R154H, H154H, R211Q, and P168Q-P240P dimorphisms died of scrapie after a longer incubation period than wild-type, G37V, Q168Q-P240P, and S240P goats. In contrast, D145D and Q222K goats were resistant to infection. The immunobiochemical signature of the scrapie isolate and its pathological aspects observed in the sheep donors were substantially maintained over 2 goat generations, i.e., after experimental and natural transmission. This demonstrates that the prion protein gene sequence, which is shared by sheep and goats, is more powerful than any possible but unknown species-related factors in determining scrapie phenotypes. With regard to genetics, our study confirms that the K222 mutation protects goats even against ovine scrapie isolates, and for the first time, a possible association of D145 mutation with scrapie resistance is shown. In addition, it is possible that the sole diverse frequencies of these genetic variants might, at least in part, shape the prevalence of scrapie among naturally exposed progenies in affected herds. IMPORTANCE This study was aimed at investigating the genetic and pathological features characterizing sheep-to-goat transmission of scrapie. We show that in goats with different prion protein gene mutations, the K222 genetic variant is associated with scrapie resistance after natural and experimental exposure to ovine prion infectivity. In addition, we observed for the first time a protective effect of the D145 goat variant against scrapie. Importantly, our results demonstrate that the phenotypic characteristic of the wild-type sheep scrapie isolate is substantially preserved in goats carrying different susceptible PRNP gene variants, thus indicating that the prion protein gene sequence, which is shared by sheep and goats, plays a fundamental role in determining scrapie phenotypes. PMID:26202249

Influence of vanadium on serum lipid and lipoprotein profiles: a population-based study among vanadium exposed workers

PubMed Central

2014-01-01

Background Some experimental animal studies reported that vanadium had beneficial effects on blood total cholesterol (TC) and triglyceride (TG). However, the relationship between vanadium exposure and lipid, lipoprotein profiles in human subjects remains uncertain. This study aimed to compare the serum lipid and lipoprotein profiles of occupational vanadium exposed and non-exposed workers, and to provide human evidence on serum lipid, lipoprotein profiles and atherogenic indexes changes in relation to vanadium exposure. Methods This cross-sectional study recruited 533 vanadium exposed workers and 241 non-exposed workers from a Steel and Iron Group in Sichuan, China. Demographic characteristics and occupational information were collected through questionnaires. Serum lipid and lipoprotein levels were measured for all participants. The ratios of total cholesterol to high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) to HDL-C and apoB to apoA-I were used as atherogenic indexes. A general linear model was applied to compare outcomes of the two groups while controlling possible confounders and multivariate logistic regression was performed to evaluate the relationship between low HDL-C level, abnormal atherogenic index and vanadium exposure. Results Higher levels of HDL-C and apoA-I could be observed in the vanadium exposed group compared with the control group (P < 0.05). Furthermore, atherogenic indexes (TC/HDL-C, LDL-C/HDL-C, and apoB/apoA-I ratios) were found statistically lower in the vanadium exposed workers (P < 0.05). Changes in HDL-C, TC/HDL-C, and LDL-C/HDL-C were more pronounced in male workers than that in female workers. In male workers, after adjusting for potential confounding variables as age, habits of smoking and drinking, occupational vanadium exposure was still associated with lower HDL-C (OR 0.41; 95% CI, 0.27-0.62) and abnormal atherogenic index (OR 0.38; 95% CI, 0.20-0.70). Conclusion Occupational vanadium exposure appears to be associated with increased HDL-C and apoA-I levels and decreased atherogenic indexes. Among male workers, a significantly negative association existed between low HDL-C level, abnormal atherogenic index and occupational vanadium exposure. This suggests vanadium has beneficial effects on blood levels of HDL-C and apoA-I. PMID:24558984

[Effects of an Individual Breast-feeding Promotion Program for Married Immigrant Women].

PubMed

Park, Mi Kyoung; Moon, So Hyun

2016-02-01

This study was designed to evaluate the effects of an individual breast-feeding promotion program to address breast-feeding knowledge, attitude, method and rate of practice for married immigrant women. A non-equivalent control group quasi-experimental design was used (experimental group=16, control group=17). The intervention consisted of 3 phases: (1) Within 2 hours of delivery - individual breast-feeding training through video/verbal/practical training education and demonstration (2) After 1~2 days - group training using video, model doll, and breast models (3) After 7 days - family visit, counseling, retraining and reinforcement training. The data were analyzed using non-parametric tests with the SPSS program. Married immigrant women who participated in the individual breast-feeding program scored high in knowledge, attitude, method and rate of practice compared to the control group. The results indicate that the individual breast-feeding program is very effective in increasing breast-feeding knowledge, attitude, method and rate of practicing breast feeding for married immigrant women. So, nurses are encouraged to aggressively utilize individual breast-feeding programs to help married immigrant women, who are exposed to vulnerability due to various situations.

Effects of Sleep after Experimental Trauma on Intrusive Emotional Memories.

PubMed

Kleim, Birgit; Wysokowsky, Julia; Schmid, Nuria; Seifritz, Erich; Rasch, Björn

2016-12-01

To investigate sleep's effect in the immediate aftermath of experiencing an analog trauma in the laboratory on reducing intrusive emotional memory formation. Sixty-five healthy women were exposed to an experimental laboratory trauma. They viewed a neutral and a trauma film in the laboratory and were randomly allocated to either a group that slept following film viewing or a group that remained awake. Sleep was recorded with electroencephalogram in a subgroup of participants in the sleep group. All participants recorded intrusive memories in the week following the film. The sleep group experienced fewer and less distressing intrusive trauma memories compared to the wake group. These effects were particularly evident toward the end of the week. Duration spent in stage N2 as opposed to light N1 sleep, a higher number of fast parietal sleep spindles and a lower rapid eye movement sleep density predicted intrusion frequency. Our results have clinical implications and set the ground for early-intervention sleep studies following trauma and prevention of chronic posttrauma disorders. © 2016 Associated Professional Sleep Societies, LLC.

[Discriminating concentrations for three insecticides used in public health in a Lutzomyia longipalpis experimental strain from Colombia].

PubMed

Marceló, Catalina; Cabrera, Olga Lucía; Santamaría, Erika

2014-01-01

In Colombia, periurban populations of Lutzomyia longipalpis , vector of the causative agent of visceral leishmaniasis in the upper and middle valley of the Magdalena River, may be exposed to insecticide applications with different purposes. Thus, it is important to begin a susceptibility surveillance of this species to insecticides. To determine indicators of susceptibility to three insecticides habitually used in public health, such as malathion, deltamethrin and lambda-cyhalothrin in an experimental strain of L. longipalpis . We used the method proposed by the Centers for Disease Control and Prevention. Groups of 10 to 15 unfed females were exposed to different concentrations of the insecticides using 250 ml glass bottles as test chambers. Mortality was registered every five minutes for an hour. Diagnostic concentrations and lethal times for each insecticide were calculated. In the evaluated L. longipalpis strain, the diagnostic concentrations and times were 75 µg/ml and 25 minutes for malathion, 10 µg/ml and 35 minutes for deltamethrin, and 15 µg/ml during 30 minutes for lambda-cyhalothrin. Baseline data over mortality response to three insecticides were established in a susceptibility strain of L. longipalpis vector. These indicators will allow establishing comparisons with populations of L. longipalpis exposed regularly or sporadically to chemical control measures to detect changes in their resistance to these insecticides.

Histological observation of hairless mice skin after exposure to Simulated Solar Light: Comparison between the histological findings with different methodologies and 3R principle correlations.

PubMed

Hossy, Bryan Hudson; Leitão, Alvaro Augusto da Costa; Torres, Renata Bosco; Ramos-E-Silva, Marcia; Miguel, Nádia Campos de Oliveira; de Pádula, Marcelo

2018-03-01

Albino hairless mouse (AHM) has been used as a biological model in photodermatology. However, the experimental landscape is diverse to follow and need particular attention. Irradiation parameters were investigated for the development of a protocol to assess alterations in the AHM skin using Simulated Solar Light (SSL). The present study was compared with published articles (last 15 years) according to irradiation protocols, morphological findings to minimize animal suffering and UV exposure. Three groups: Control (G1), experimental - sunburn (G2) and skin photodamage assay (G3). G2 were immobilized and exposed to SSL once for 15, 30 and 45min. G3 were exposed to SSL, without immobilization, for 15min once a day for one week. The dorsal skin was analyzed using hematoxylin and eosin technique. G2 displayed different sunburn degrees. Based on the profile of the observed morphological alterations, a 15min irradiation was chosen as the exposure time to expose G3, without immobilization, for 5 consecutive days. These conditions produced the same morphological changes in the AHM with a shorter solar exposure time, without immobilizing the animals but using environmental exposure fluences, conforming to 3R (reduction - refinement - replacement) recommendations. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Modification in oxidative processes in muscle tissues exposed to laser- and light-emitting diode radiation.

PubMed

Monich, Victor A; Bavrina, Anna P; Malinovskaya, Svetlana L

2018-01-01

Exposure of living tissues to high-intensity red or near-infrared light can produce the oxidative stress effects both in the target zone and adjacent ones. The protein oxidative modification (POM) products can be used as reliable and early markers of oxidative stress. The contents of modified proteins in the investigated specimens can be evaluated by the 2,4-dinitrophenylhydrazine assay (the DNPH assay). Low-intensity red light is able to decrease the activity of oxidative processes and the DNPH assay data about the POM products in the biological tissues could show both an oxidative stress level and an efficiency of physical agent protection against the oxidative processes. Two control groups of white rats were irradiated by laser light, the first control group by red light and the second one by near-infrared radiation (NIR).Two experimental groups were consequently treated with laser and red low-level light-emitting diode radiation (LED). One of them was exposed to red laser light + LED and the other to NIR + LED. The fifth group was intact. Each group included ten animals. The effect of laser light was studied by methods of protein oxidative modifications. We measured levels of both induced and spontaneous POM products by the DNPH assay. The dramatic increase in levels of POM products in the control group samples when compared with the intact group data as well as the sharp decrease in the POM products in the experimental groups treated with LED low-level light were statistically significant (p ≤ 0.05). Exposure of skeletal muscles to high-intensity red and near-infrared laser light causes oxidative stress that continues not less than 3 days. The method of measurement of POM product contents by the DNPH assay is a reliable test of an oxidative process rate. Red low-intensity LED radiation can provide rehabilitation of skeletal muscle tissues treated with high-intensity laser light.

Performance and exposure indices of rats exposed to low concentrations of lead.

PubMed

Cory-Slechta, D A; Weiss, B; Cox, C

1985-04-01

To further characterize the lower end of the function relating lead exposure and biological exposure indices to behavior, male weanling rats were exposed chronically to drinking solutions containing 25 ppm sodium acetate (controls) or 25 ppm lead acetate. Behavioral training began when the animals reached 50 days of age, and performance on a fixed-interval 1-min schedule of food reinforcement was then assessed over 90 experimental sessions (136 days). This exposure produced overall response rate increases over the first 40 sessions that were similar to those observed previously with higher concentrations of lead. Response rates of the two groups tended to merge subsequently. The increased overall response rates in the treated group derived primarily from an increased frequency of shorter interresponse times (IRTs) and increased running rates (calculated without the postreinforcement interval). Blood lead (PbB) and zinc protoporphyrin (ZPP) values were determined following sessions 30, 60, and 90. PbB values of the lead-exposed group averaged 15 to 20 micrograms/dl throughout the study; ZPP did not differ. The mean brain lead value of the treated group was 0.07 micrograms Pb/g. Blood-brain ratios (1.38 to 4.06) were substantially greater than those previously observed at higher exposures. These data extend to even lower exposures, and lower blood lead concentrations, the effective concentration for behavioral effects, and further emphasize the importance of the sensitivity of the endpoint in assessing behavioral toxicity.

Irradiation inhibits vascular anastomotic stenosis in a canine model.

PubMed

Saito, Takeshi; Iguchi, Atsushi; Tabayashi, Koichi

2009-08-01

The graft patency rate after coronary artery bypass grafting (CABG) correlates with anastomotic stenosis. Intracoronary radiation therapy is effective for preventing restenosis after percutaneous coronary intervention (PCI). We postulated that intracoronary radiation therapy could prevent anastomotic stenosis and tested this hypothesis in an animal model. Femoral arteries and veins of beagle dogs were harvested, and composite arterioarterial and arteriovenous grafts were prepared. After external irradiation of the anastomotic sites, these composite grafts were transplanted into femoral arteries. Histomorphometric and immunohistological analyses of the anastomotic sites were performed. The study groups consisted of controls and animals exposed to 10 Gy, 20 Gy, and 30 Gy (n = 5, in each group). In the artery graft model, the ratio of negative remodeling was significantly increased in all groups exposed to >or=10 Gy. The ratio of neointimal hyperplasia was significantly decreased in all groups exposed to >or=10 Gy. Cell density of anti-alpha-actin antibody-positive cells and anti-proliferating cell nuclear antigen (PCNA) antibody-positive cells was highest in the adventitial layer, and the density decreased as the dosage increased. Experimental results were almost the same in the vein graft models as in the artery graft models. With double immunohistostaining, the anti-PCNA antibody-positive cells expressed alpha-actin. Irradiation can inhibit anastomotic stenosis in a canine model. Adventitia is a factor in the creation of stenosis, and irradiation appears to target the adventitia. We speculate that there might be a possible role for intracoronary irradiation in the future to prevent anastomotic stenosis.

Children's differential susceptibility to parenting: An experimental test of "for better and for worse".

PubMed

Slagt, Meike; Dubas, Judith Semon; van Aken, Marcel A G; Ellis, Bruce J; Deković, Maja

2017-02-01

Differential susceptibility theory proposes that a subset of individuals exist who display enhanced susceptibility to both negative (risk-promoting) and positive (development-enhancing) environments. This experiment represents the first attempt to directly test this assumption by exposing children in the experimental group to both negative and positive feedback using puppet role-plays. It thereby serves as an empirical test as well as a methodological primer for testing differential susceptibility. Dutch children (N=190, 45.3% girls) between the ages of 4 and 6years participated. We examined whether negative and positive feedback would differentially affect changes in positive and negative affect, in prosocial and antisocial intentions and behavior, depending on children's negative emotionality. Results show that on hearing negative feedback, children in the experimental group increased in negative affect and decreased in positive affect more strongly than children in the control group. On hearing positive feedback, children in the experimental group tended to increase in positive affect and decrease in prosocial behavior. However, changes in response to negative or positive feedback did not depend on children's negative emotionality. Moreover, using reliable change scores, we found support for a subset of "vulnerable" children but not for a subset of "susceptible" children. The findings offer suggestions to guide future differential susceptibility experiments. Copyright © 2016 Elsevier Inc. All rights reserved.

Histological study on hippocampus, amygdala and cerebellum following low lead exposure during prenatal and postnatal brain development in rats.

PubMed

Barkur, Rajashekar Rao; Bairy, Laxminarayana K

2016-06-01

Neuropsychological studies in children who are exposed to lead during their early brain development have shown to develop behavioural and cognitive deficit. The aim of the present study was to assess the cellular damage in hippocampus, amygdala and cerebellum of rat pups exposed to lead during different periods of early brain development. Five groups of rat pups were investigated. (a) Control group (n = 8) (mothers of these rats were given normal drinking water throughout gestation and lactation), (b) pregestation lead-exposed group (n = 8) (mothers of these rats were exposed to 0.2% lead acetate in the drinking water for one month before conception), (c) gestation lead-exposed group (n = 8) (exposed to 0.2% lead acetate in the drinking water through the mother throughout gestation [gestation day 01 to day 21]), (d) lactation lead-exposed group (n = 8) (exposed to 0.2% lead acetate in the drinking water through the mother throughout lactation [postnatal day 01 to day 21]) and (e) gestation and lactation lead-exposed group (n = 8) (exposed to 0.2% lead acetate throughout gestation and lactation). On postnatal day 30, rat pups of all the groups were killed. Numbers of surviving neurons in the hippocampus, amygdala and cerebellum regions were counted using cresyl violet staining technique. Histological data indicate that lead exposure caused significant damage to neurons of hippocampus, amygdala and cerebellum regions in all lead-exposed groups except lactation lead-exposed group. The extent of damage to neurons of hippocampus, amygdala and cerebellum regions in lactation lead-exposed group was comparable to gestation and lactation groups even though the duration of lead exposure was much less in lactation lead-exposed group. To conclude, the postnatal period of brain development seems to be more vulnerable to lead neurotoxicity compared to prenatal period of brain development. © The Author(s) 2014.

Long-term effects of pesticide exposure at various life stages of the southern leopard frog (Rana sphenocephala)

USGS Publications Warehouse

Bridges, C.M.

2000-01-01

Amphibian larvae are commonly exposed to low levels of pesticides during their development. Chronic studies generally examine the effects of long-term exposure, but they often disregard the importance of the individual life stage at which tadpoles are exposed. I determined the point during development at which carbaryl effects are manifested by exposing southern leopard frog tadpoles (Rana sphenocephala) to the pesticide carbaryl at five different times during development. Metamorphs exposed throughout the tadpole stage and throughout development (egg, embryo, tadpole) experienced significant mortality at all chemical levels. Although the length of the larval period was the same for all experimental groups, metamorphs exposed during the egg stage were smaller than their corresponding controls, independent of whether they were exposed at any other stage. Nearly 18% of individuals exposed to carbaryl during development exhibited some type of developmental deformity (including both visceral and limb malformities), compared to a single deformed (< 1%) control tadpole, demonstrating that a chemical hypothesis for amphibian deformities remains viable. Because exposure to nonpersistent chemicals may last for only a short period of time, it is important to examine the long-term effects that short-term exposure has on larval amphibians and the existence of any sensitive life stage. Any delay in metamorphosis or decrease in size at metamorphosis can impact demographic processes of the population, potentially leading to declines or local extinction.

The virtual child: evaluation of an internet-based pediatric behavior management simulation.

PubMed

Boynton, James R; Green, Thomas G; Johnson, Lynn A; Nainar, S M Hashim; Straffon, Lloyd H

2007-09-01

This article describes an Internet-based instructional tool designed to give predoctoral dental students a virtual simulation of clinical pediatric dentistry to develop their pediatric behavior management knowledge. Effectiveness of this tool was evaluated using two consecutive classes of junior dental students. The control group was exposed to the traditional behavior management curriculum (two lectures) in a spring term course. The next class of dental students was exposed to the two lectures and, in addition, completed the behavior management simulation during the following spring term. Both groups completed a two-part examination (objective section=18 questions; open-ended section=responses to a clinical situation) designed to test their behavior management knowledge. The simulation group performed significantly better in both parts of the examination (objective section: p=.028; open-ended section: p=.012). The simulation was evaluated by students and perceived by most to be an effective addition to the curriculum. It was concluded that the experimental behavior management simulation, when added to the traditional lecture curriculum, improved pediatric behavior management knowledge in predoctoral dental students.

Subchronic inhalation of coal dust particulate matter 10 induces bronchoalveolar hyperplasia and decreases MUC5AC expression in male Wistar rats.

PubMed

Kania, Nia; Setiawan, Bambang; Widjadjanto, Edi; Nurdiana, Nurdiana; Widodo, M Aris; Kusuma, H M S Chandra

2014-10-01

Coal dust is a pollutant found in coal mines that are capable of inducing oxidative stress and inflammation, but the effects on lung metaplasia as an early step of carcinogenesis remain unknown. The purpose of the present study was to evaluate the effects of PM10 coal dust on lung histology, MUC5AC expression, epidermal growth factor (EGF) expression, and epidermal growth factor receptor (EGFR) expression. An experimental study was done on male Wistar rats, which were divided into the following groups: control groups exposed to coal dust for 14 days (at doses of 6.25 mg/m(3), 12.5 mg/m(3), and 25 mg/m(3)), and the groups exposed to coal dust for 28 days (at doses of 6.25 mg/m(3), 12.5 mg/m(3), and 25 mg/m(3)). EGF expressions in rat lungs were measured by ELISA. EGFR and MUC5AC were measured by a confocal laser scanning microscope. The bronchoalveolar epithelial image of the group exposed to coal dust for 14 and 28 days showed a epithelial rearrangement, hyperplastic (metaplastic) goblet cells, and scattered massive inflammatory cells. The pulmonary parenchymal image of the group of exposed to coal dust for 14 and 28 days showed scattered inflammatory cells filling up the pulmonary alveolar networks, leading to an appearance of thickened parenchymal alveoli until emphysema-like structure. There was no significant difference in MUC5AC, EGF, and EGFR expressions for 14-d exposure (p>0.05). There was no significant difference in EGF and EGFR expressions for 28-d exposure (p>0.05), but there was a significant difference in MUC5AC expression (p<0.05). We concluded that subchronic inhalation of coal dust particulate matter 10 induces bronchoalveolar reactive hyperplasia and rearrangement of epithelial cells which accompanied by decrease expression MUC5AC in male rats. Copyright © 2014 Elsevier GmbH. All rights reserved.

Significance of biorhythms in space flight

NASA Technical Reports Server (NTRS)

Winget, C. M.

1975-01-01

Evidence is presented that the most important factor in the maintenance of optimal health and performance is the stability of the relationship of one body rhythm to another. The effect of social interaction on performance, well-being, and physiological rhythm synchrony was investigated. Three groups of healthy males, ages 21 to 25, were confined in rooms (3.4 by 5.2 meters (11 by 17 feet)) for a total period of 105 days. Two of the groups were in rooms in which the environment could be regulated. The third group served as the control group and was exposed to ambient experimental conditions. The confined subjects were exposed for periods to several days either to 16 hours of light and 8 hours of dark, or to continuous light at a light intensity of 161 lm/sq m (15 foot-candles). The confined subjects were deprived of all time cues, and meals were ad libitum. The subjects were observed throughout the study by a video camera and were scored for activity. Communications were limited to meal and sample-collection information, and meals and samples were passed through a two-way hatch. Rectal temperature and heart rate (HR) were sampled every 30 minutes by telemetry throughout the study. Results are presented.

Evaluation of the immunological cellular response of Cebus apella exposed to the carcinogen N-methyl-N-nitrosourea and treated with CANOVA®.

PubMed

Feio, Danielle Cristinne Azevedo; Muniz, José Augusto Pereira Carneiro; Montenegro, Raquel Carvalho; Burbano, Rommel Rodriguez; De Brito Junior, Lacy Cardoso; De Lima, Patrícia Danielle Lima

2014-01-01

The immune response modifier Canova® is a homeopathic remedy indicated for patients with depressed immune system, since this drug appears to increase adaptive immunity and induce an immune response against multiple and severe pathological conditions, including cancer. We evaluated the pattern of immune cellular response in non-human primates of the species Cebus apella exposed to N-methyl-N-nitrosourea (MNU) with and without Canova®. Twelve animals were divided into four groups, with three animals each: negative control and three experimental groups, MNU-alone (35 days); MNU (35 days)-plus-Canova® (3 days) and Canova®-alone (3 days). The animals received MNU orally and Canova® by three intravenous injections. Evaluation of the cellular immune response was performed by immunophenotyping of T-lymphocytes (CD4(+), CD8(+)), B-lymphocytes and natural killer cells. Analysis was also performed of the cell cycle. Our results suggest an increase of T-lymphocytes (CD4(+)CD3(+)) only in the Canova® group, while in the MNU-plus-Canova® group only B-lymphocytes increased. Copyright © 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Recognition of facial expressions of mixed emotions in school-age children exposed to terrorism.

PubMed

Scrimin, Sara; Moscardino, Ughetta; Capello, Fabia; Altoè, Gianmarco; Axia, Giovanna

2009-09-01

This exploratory study aims at investigating the effects of terrorism on children's ability to recognize emotions. A sample of 101 exposed and 102 nonexposed children (mean age = 11 years), balanced for age and gender, were assessed 20 months after a terrorist attack in Beslan, Russia. Two trials controlled for children's ability to match a facial emotional stimulus with an emotional label and their ability to match an emotional label with an emotional context. The experimental trial evaluated the relation between exposure to terrorism and children's free labeling of mixed emotion facial stimuli created by morphing between 2 prototypical emotions. Repeated measures analyses of covariance revealed that exposed children correctly recognized pure emotions. Four log-linear models were performed to explore the association between exposure group and category of answer given in response to different mixed emotion facial stimuli. Model parameters indicated that, compared with nonexposed children, exposed children (a) labeled facial expressions containing anger and sadness significantly more often than expected as anger, and (b) produced fewer correct answers in response to stimuli containing sadness as a target emotion.

Transmission of stress between cagemates: a study in rats.

PubMed

Akyazi, Ibrahim; Eraslan, Evren

2014-01-17

The neuroendocrine responses triggered by stressors cause significant behavioral changes in animals. Considering the continuous behavioral interaction between social animals, it would be reasonable to suggest that the aforementioned behavioral changes can lead to transmission of stress between individuals. In the present study the aim is to investigate the outcomes of the behavioral interaction between stressed and unstressed animals housed together. A total of 28 adult male Wistar rats were used in the study. The animals were randomly allocated to four groups. Two of the groups were exposed to white noise stress in a period of 15days, while the other two groups remained unstressed. One of the stress exposed groups served as the stress control (SC) group and one of the non-stressed groups served as the reference value (RV) group. The remaining two groups were transmission groups. Every two animals of the non-stressed transmission group (TC) have been housed with two other animals of the stress exposed transmission group (TS) during the experimental period. After the stress exposure period, six animals from each group were subjected to behavioral assessment in an elevated plus maze (EPM), and subsequently, their cortisol levels were determined. White noise exposure of animals in the SC group induced a stress response indicated by an 1.8 fold increase of plasma cortisol level compared to the RV group (2.11±0.43 and 1.16±0,02, respectively). The transmission groups (TS and TC) entered the open arms more frequently and spent more time in open arms compared to the RV group. White noise exposure caused a stress response characterized by an elevation of cortisol level in rats. The gradual decrease of cortisol level from the SC towards the RV group may be interpreted as an evidence supporting the hypothesis of stress-transmission between cagemates. The moderate stress levels of the transmission groups, but not low and high levels of the SC and RV groups, decreased the anxiety-like behavior, which indicates an inverted U-shaped relationship between stress levels and anxiolytic effectiveness. © 2013.

Investigating the effect of music on labor pain and progress in the active stage of first labor.

PubMed

Hosseini, S E; Bagheri, M; Honarparvaran, N

2013-06-01

DESIGN AND PURPOSE: The purpose of this study is to investigate the effects of music-therapy on labor pain and progress in parturient primipara. Music-therapy during labor increases tolerance to pain; decreasing anxiety, it increases paturition and uterus activity and shorten labor duration. The subjects of this research were 30 women, selected voluntarily and they have been put in two experimental and control group. This research has been conducted in the form of pre-test and post-test design. The experimental group listened to a relaxing music for 30 minutes in each hour for a two-hour period a nd the control group was not exposed to music during this period. For the purpose of gathering data in both groups, the pain scales (verbal, numeric and visual) was used to measure pain. The independent variable in this research is relaxing music and the dependent variables are the pain level and delivery progress. The independent t for sensations of pain in the experimental and control group before intervention has been (p = 0.875) 0.601 in numeric and visual pain and (p < 0.01) 2.92 in verbal pain, and one hour after intervention, it has been (p < 0.0001) 8.527 in visual and numeric pain and (p < 0.0001) 11.824 in verbal pain. Also, the equal value of independent t for the duration of delivery in control group before and after intervention shows that music has not had any effect on the rate of serotonin. The results of statistical analysis show the effect of music on the decrease of sensation of pain in the experimental group as compared with the control group.

Telencephalic neural activation following passive avoidance learning in a terrestrial toad.

PubMed

Puddington, Martín M; Daneri, M Florencia; Papini, Mauricio R; Muzio, Rubén N

2016-12-15

The present study explores passive avoidance learning and its neural basis in toads (Rhinella arenarum). In Experiment 1, two groups of toads learned to move from a lighted compartment into a dark compartment. After responding, animals in the experimental condition were exposed to an 800-mM strongly hypertonic NaCl solution that leads to weight loss. Control animals received exposure to a 300-mM slightly hypertonic NaCl solution that leads to neither weight gain nor loss. After 10 daily acquisition trials, animals in the experimental group showed significantly longer latency to enter the dark compartment. Additionally, 10 daily trials in which both groups received the 300-mM NaCl solution after responding eliminated this group effect. Thus, experimental animals showed gradual acquisition and extinction of a passive avoidance respond. Experiment 2 replicated the gradual acquisition effect, but, after the last trial, animals were sacrificed and neural activation was assessed in five brain regions using AgNOR staining for nucleoli-an index of brain activity. Higher activation in the experimental animals, relative to controls, was observed in the amygdala and striatum. Group differences in two other regions, lateral pallium and septum, were borderline, but nonsignificant, whereas group differences in the medial pallium were nonsignificant. These preliminary results suggest that a striatal-amygdala activation could be a key component of the brain circuit controlling passive avoidance learning in amphibians. The results are discussed in relation to the results of analogous experiments with other vertebrates. Copyright © 2016 Elsevier B.V. All rights reserved.

[The effect of bacteria reaction time on corrosion properties of Ni-Cr alloys pretreated with different proteins].

PubMed

Qi, Han-quan; Zhang, Song-mei; Qian, Chao; Yuan-Li, Zheng

2015-12-01

To evaluate the corrosion properties of absorbed protein on the surface of NiCr alloys, and provide experimental base for corrosion resistance of dental casting alloys. NiCr alloy specimens were divided into 3 groups: one group was exposed to the artificial saliva(control group), and the other 2 groups were exposed to the artificial saliva with 1% bovine serum albumin(BSA), or 0.22% lysozyme(LSZ). Group of BSA and group of LSZ were the experimental group. Specimens in 3 groups were cultured in solution of Streptococcus mutans for 12 h, 24 h, 36 h and 48h, and investigated with electrochemical impedance spectroscopy measurement(EIS) and potentiodynamic polarization measurement(POT) to determine the corrosion resistance of the alloys. The data was analyzed with SPSS 17.0 software package. The results indicated that the corrosion resistance of both BSA group and LSZ group were higher than that of the control group (P<0.05) and LSZ group was superior to BSA group cultured in the solution of Streptococcus mutans for 12 h. When cultured for 24 h, the corrosion resistance of BSA group and LSZ group had no significant difference (P>0.05), but was still higher than that of the control group. After 36 h culture time, the control group and the BSA group had no statistical difference in corrosion resistance （P>0.05), while the LSZ group had the poorest corrosion resistance. When the culture time extended to 48 h, the control group had a better corrosion resistance compared with the BAS group and the LSZ group(P<0.05), but BSA group had displayed lower corrosion properties than LSZ group. The potentiodynamic polarization curve and electrochemical impedance spectroscopy had similar results. The adhesion of BSA and LSZ on the surface of the NiCr alloys in the early time could effectively inhibit the corrosive effect of Streptococcus mutans. The LSZ had better effect than BSA. With the continuing role of bacteria and the consumption of the absorb protein, the corrosion resistance of NiCr alloys toward Streptococcus mutans becomes lower than the alloys without absorb protein, which demonstrated that the adhesion of protein would change the surface structure of NiCr alloys and BSA had a greater effect.

Role of Scoparia dulcis linn on noise-induced nitric oxide synthase (NOS) expression and neurotransmitter assessment on motor function in Wistar albino rats.

PubMed

Wankhar, Wankupar; Srinivasan, Sakthivel; Sundareswaran, Loganathan; Wankhar, Dapkupar; Rajan, Ravindran; Sheeladevi, Rathinasamy

2017-02-01

Noise pollution is one of the most widespread and fast growing environmental and occupational menaces in the modern era. Exposure to noise above 100dB is not adaptable through the brain homeostatic mechanism. Yet, the detrimental effects of noise have often been ignored. Developing reliable animal models to understand the neurobiology of noise stress and advance our research in the field of medicine to impede this growing stressor is needed. In this study experimental animals were divided into four groups, (i) Control and (ii) S. dulcis extract (200mg/kgbw) treated control group. (iii) To mimic the influence of noise, animals in this group were exposed to noise stress (100dB/4h/day) for 15days and finally, (iv) Noise exposed treated with S. dulcis extract (200mg/kgbw) group. Rota-rod and narrow beam performance results showed impaired motor co-ordination in noise exposed group on both 1st and 15th day when compared to controls. This impaired motor function on exposure to noise could be attributed to the altered norepinephrine, dopamine and serotonin levels in both the striatum and cerebellum. Moreover, the motor impaired associated changes could also be attributed to upregulated nNOS and iNOS protein expression in the cerebellum resulting in increased nitric oxide radical production. This increased reactive free radicals species can initiate lipid peroxidation mediated changes in the cerebellar Purkinje cells, which is responsible for initiating inhibitory motor response and ultimately leading to impaired motor co-ordination. Treatment with S. dulcis extract (200mg/kgbw) could control motor impairment and regulate neurotransmitter level as that of control groups when compared to noise exposed group. One key aspect of therapeutic efficacy of the plant could have resulted due to attenuated lipid peroxidation mediated damages on the cerebellar Purkinje cells thereby regulating motor impairment. Thus, targeting the antioxidant and free radicals scavenging properties of the plant could serve as a potential therapeutic to combat this environmental stressor. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Experimental exposure to methylformate and its neurobehavioral effects.

PubMed

Sethre, T; Läubli, T; Berode, M; Hangartner, M; Krueger, H

2000-08-01

The aim of the study was to investigate the acute effects of experimental methylformate exposure on the nervous system. In an exposure chamber, 20 subjects were exposed to methylformate at 100 ppm [Swiss maximum allowable concentration (MAC)] for 8 h. The same number of subjects with the same ages (between 20 and 30 years), gender and education level (university) were examined by the same procedure as a control group. The subjects did not know if they were exposed or not. Three times (morning, noon, evening) during these 8 h, mood [Profile of Mood States (POMS)], neurobehavioral performance (reaction, Stroop, nonverbal learning, determination, tracking; Wiener Test System), vision (visual acuity, contrast sensitivity, color sensitivity) and postural sway were tested. During an undemanding test (POMS) and a demanding performance task (determination test), pulse, electromyography (EMG) of the forehead and of the neck were recorded. In the morning and evening spirometry [forced vital capacity (FVC), forced one-second expiration volume (FEV), medium expiration flow (MEF) and peak expiration flow (PEF)] and the odor perception threshold were measured. In the evening, in the exposed group, fatigue was significantly increased and the EMG of the forehead during a demanding task showed a different development during exposure. The other tests showed no significant solvent effect, but 16 of 43 test parameters showed a significant effect of time. The results of this study indicate a possible effect of methylformate exposure on the subjective feeling of fatigue after 8 h exposure at 100 ppm in young and healthy subjects, without measurable impairment of neurobehavioral performance. We assume that a similar effect in normal work, combined with a heavy workload and shift work, can lead to an impairment of productivity, and increase the risk of accidents.

Multigenerational effects of whole body exposure to 2.14 GHz W-CDMA cellular phone signals on brain function in rats.

PubMed

Shirai, Tomoyuki; Imai, Norio; Wang, Jianqing; Takahashi, Satoru; Kawabe, Mayumi; Wake, Kanako; Kawai, Hiroki; Watanabe, So-Ichi; Furukawa, Fumio; Fujiwara, Osamu

2014-10-01

The present experimental study was carried out with rats to evaluate the effects of whole body exposure to 2.14 GHz band code division multiple access (W-CDMA) signals for 20 h a day, over three generations. The average specific absorption rate (SAR, in unit of W/kg) for dams was designed at three levels: high (<0.24 W/kg), low (<0.08 W/kg), and 0 (sham exposure). Pregnant mothers (4 rats/group) were exposed from gestational day (GD) 7 to weaning and then their offspring (F1 generation, 4 males and 4 females/dam, respectively) were continuously exposed until 6 weeks of age. The F1 females were mated with F1 males at 11 weeks old, and then starting from GD 7, they were exposed continuously to the electromagnetic field (EMF; one half of the F1 offspring was used for mating, that is, two of each sex per dam and 8 males and 8 females/group, except for all offspring for the functional development tests). This protocol was repeated in the same manner on pregnant F2 females and F3 pups; the latter were killed at 10 weeks of age. No abnormalities were observed in the mother rats (F0 , F1 , and F2 ) and in the offspring (F1 , F2 , and F3 ) in any biological parameters, including neurobehavioral function. Thus, it was concluded that under the experimental conditions applied, multigenerational whole body exposure to 2.14 GHz W-CDMA signals for 20 h/day did not cause any adverse effects on the F1 , F2 , and F3 offspring. © 2014 Wiley Periodicals, Inc.

Influence of laser radiation on the growth and development of seeds of agricultural plants

NASA Astrophysics Data System (ADS)

Grishkanich, Alexander; Zhevlakov, Alexander; Polyakov, Vadim; Kascheev, Sergey; Sidorov, Igor; Ruzankina, Julia; Yakovlev, Alexey; Mak, Andrey

2016-04-01

The experimental results presented in this study focused on the study of biological processes caused by exposure to the coating layers of the laser green light seed (λ = 532 nm) range for the larch, violet (λ = 405 nm) and red (λ = 640 nm) for spruce. Spend a series of experiments to study the dependence of crop seed quality (spruce and larch from the pine family) from exposure to laser radiation under different conditions. In all the analyzed groups studied seed germination and growth of seedlings exposed to laser exposure, compared with the control group. The results showed that the higher percentage of germination than seeds of the control group.

The ontogeny of the homing pigeon navigational map: evidence for a sensitive learning period.

PubMed Central

Gagliardo, A; Ioalè, P; Odetti, F; Bingman, V P

2001-01-01

Homing pigeons can learn a navigational map by relying on the heterogeneous distribution of atmospheric odours in the environment. To test whether there might be a sensitive period for learning an olfactory-based navigational map, we maintained a group of young pigeons in an aviary screened from the winds until the age of three to four months post-fledging. Subsequently, the screens were removed and the pigeons were exposed to the winds and the environmental odours they carry for three months. One control group of pigeons was held in a similar aviary but exposed to the winds immediately upon Hedging, while another control group of pigeons was allowed free-flight. When the pigeons from the three groups were released from two distant release sites at about six months of age post-fledging, the two control groups were found to be equally good at orientating and returning home, while the experimental pigeons held in the shielded aviary for the first three months post-fledging were unable to orientate homeward and they were generally unsuccessful in returning home. This result supports the hypothesis that environmental experience during the first three months post-fledging is critical for some aspect of navigational map learning and that navigational map learning displays sensitive period-like properties. PMID:11209891

The ontogeny of the homing pigeon navigational map: evidence for a sensitive learning period.

PubMed

Gagliardo, A; Ioalè, P; Odetti, F; Bingman, V P

2001-01-22

Homing pigeons can learn a navigational map by relying on the heterogeneous distribution of atmospheric odours in the environment. To test whether there might be a sensitive period for learning an olfactory-based navigational map, we maintained a group of young pigeons in an aviary screened from the winds until the age of three to four months post-fledging. Subsequently, the screens were removed and the pigeons were exposed to the winds and the environmental odours they carry for three months. One control group of pigeons was held in a similar aviary but exposed to the winds immediately upon Hedging, while another control group of pigeons was allowed free-flight. When the pigeons from the three groups were released from two distant release sites at about six months of age post-fledging, the two control groups were found to be equally good at orientating and returning home, while the experimental pigeons held in the shielded aviary for the first three months post-fledging were unable to orientate homeward and they were generally unsuccessful in returning home. This result supports the hypothesis that environmental experience during the first three months post-fledging is critical for some aspect of navigational map learning and that navigational map learning displays sensitive period-like properties.

Protective effects of omega-3 essential fatty acids against formaldehyde-induced cerebellar damage in rats.

PubMed

Zararsiz, Ismail; Meydan, Sedat; Sarsilmaz, Mustafa; Songur, Ahmet; Ozen, Oguz Aslan; Sogut, Sadik

2011-07-01

This study aimed to investigate changes in the cerebellum of formaldehyde-exposed rats and the effects of omega-3 fatty acids on these changes. The study involved 21 male Wistar-Albino rats which were divided into three groups. The rats in Group I comprised the control group. The rats in Group II were injected with intraperitoneal 10% formaldehyde every other day. The rats in Group III received omega-3 fatty acids daily while exposed to formaldehyde. At the end of the 14-day experimental period, all rats were killed by decapitation and the cerebellum removed. The activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), xanthine oxidase (XO), and malondialdehyde (MDA) levels were determined in cerebellum specimens by using spectrophotometric methods. In our study, levels of SOD and CAT were significantly decreased, and GSH-Px, XO, MDA levels were significantly increased in rats treated with formaldehyde compared with those of the controls. Whereas, it was seen that there was an increase in SOD and CAT enzyme activities and decrease in MDA, XO, and GSH-Px levels in rats administered to omega-3 fatty acids with exposure of formaldehyde. It was determined that exposure of formaldehyde increased free radicals in cerebellum of rats and this increase was prevented by administration of omega-3 fatty acids.

The effect of IDS (immediate dentin sealing) on dentin bond strength under various thermocycling periods

PubMed Central

Leesungbok, Richard; Lee, Sang-Min; Park, Su-Jung; Lee, Suk-Won; Lee, Do Yun; Im, Byung-Jin

2015-01-01

PURPOSE The purpose of this study was to find out the effect of immediate dentin sealing (IDS) on bond strength of ceramic restoration under various thermocycling periods with DBA (dentin bonding agent system). MATERIALS AND METHODS Fifty freshly extracted human mandibular third molars were divided into 5 groups (1 control and 4 experimental groups) of 10 teeth. We removed enamel layer of sound teeth and embedded them which will proceed to be IDS, using All Bond II. A thermocycling was applied to experimental groups for 1, 2, 7, 14 days respectively and was not applied to control group. IPS Empress II for ceramic was acid-etched with ceramic etchant (9.5% HF) and silane was applied. Each ceramic disc was bonded to specimens with Duo-link, dual curable resin cement by means of light curing for 100 seconds. After the cementation procedures, shear bond strength measurement and SEM analysis of the fractured surface were done. The data were analyzed with a one-way ANOVA and Tukey multiple comparison test (α=.05). RESULTS There were no statistically significant differences between 4 experimental groups and control group, however the mean value started to decrease in group 7d, and group 14d showed the lowest mean bond strength in all groups. Also, group 7d and 14d showed distinct exposed dentin and collapsed hybrid layer was observed in SEM analysis. CONCLUSION In the present study, it can be concluded that ceramic restorations like a laminate veneer restoration should be bonded using resin cement within one week after IDS procedure. PMID:26140174

Neuroprotective effects of Quercetin on radiation-induced brain injury in rats.

PubMed

Kale, Aydemir; Piskin, Özcan; Bas, Yilmaz; Aydin, Bengü Gülhan; Can, Murat; Elmas, Özlem; Büyükuysal, Çagatay

2018-04-24

Extensive research has been focused on radiation-induced brain injury. Animal and human studies have shown that flavonoids have remarkable toxicological profiles. This study aims to investigate the neuroprotective effects of quercetin in an experimental radiation-induced brain injury. A total of 32 adult male Wistar-Albino rats were randomly divided into four groups (control, quercetin, radiation, and radiation+quercetin groups, with eight rats in each group). Doses (50 mg/kg) of quercetin were administered to the animals in the quercetin and radiation+quercetin groups; radiation and radiation+quercetin groups were exposed to a dose of 20 Gy to the cranium region. Tissue samples, and biochemical levels of tissue injury markers in the four groups were compared. In all measured parameters of oxidative stress, administration of quercetin significantly demonstrated favorable effects. Both plasma and tissue levels of malondialdehyde and total antioxidant status significantly changed in favor of antioxidant activity. Histopathological evaluation of the tissues also demonstrated a significant decrease in cellular degeneration and infiltration parameters after quercetin administration. Quercetin demonstrated significant neuroprotection after radiation-induced brain injury. Further studies of neurological outcomes under different experimental settings are required in order to achieve conclusive results.

Bifidobacterium bifidum in a Rat Model of Necrotizing Enterocolitis: Antimicrobial Peptide and Protein Responses

PubMed Central

Underwood, Mark A.; Kananurak, Anchasa; Coursodon, Christine F.; Adkins-Reick, Camille K.; Chu, Hiutung; Bennett, Stephen H.; Wehkamp, Jan; Castillo, Patricia A.; Leonard, Brian C.; Tancredi, Daniel J.; Sherman, Michael P.; Dvorak, Bohuslav; Bevins, Charles L.

2013-01-01

Necrotizing enterocolitis (NEC) is a devastating disease of premature infants. Probiotics decrease the risk of NEC in clinical and experimental studies. Antimicrobial peptides protect the gut against noxious microbes and shape the commensal microbiota, but their role in NEC remains unclear. We report that like in human ontogeny, the rat pup has low expression of Paneth cell antimicrobials, which increases rapidly during normal development. To investigate the expression of antimicrobial peptides in experimental NEC and the impact of probiotics on their expression, premature rats were divided into three groups: dam fed (DF), hand fed with formula (FF), or hand fed with formula containing Bifidobacterium bifidum (FF+BIF). All groups were exposed to asphyxia and cold stress. The expression of lysozyme, secretory phospholipase A2, pancreatic-associated proteins 1 and 3 mRNA was elevated in the FF (NEC) group, compared to the DF and FF+BIF groups where disease was attenuated. We conclude that induction of antimicrobial peptides occurs in experimental NEC similar to that reported in human disease and is attenuated when disease is averted by probiotic B. bifidum. The induction of antimicrobial peptides is likely an adaptive mucosal response that is often not sufficient to prevent disease in the premature gut. PMID:22322385

Changes of reduced glutathion, glutathion reductase, and glutathione peroxidase after radiation in guinea pigs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erden, M.; Bor, N.M.

1984-04-01

In this series of experiments the protective action of reduced glutathion due to ionizing radiation has been studied. In the experimental group 18 guinea pigs were exposed to successive radiations of 150 rad 3 or 4 days apart. Total dose given amounted to 750 rad which is the LD50 for guinea pigs. Blood samples were taken 30 min after each exposure. The control series were sham radiated but otherwise treated identically. The cells of the removed blood samples were separated by centrifugation and were subjected to the reduced glutathion stability test. GSSGR, GPer, and LDH enzyme activities were also measuredmore » of which the latter served as a marked enzyme. It was found that LDH did not show any alteration after radiation. The reduced glutathion stability test showed a consistent but minor reduction (P greater than 0.05), in the experimental group. GSSGR enzyme activity on the other hand was reduced significantly (from 176.48 +/- 11.32 to 41.34 +/- 1.17 IU/ml of packed erythrocytes, P less than 0.001) in the same group. GPer activity showed a consistent but minor elevation during the early phase of the experimental group. It was later increased significantly beginning after 600 rad total radiation on the fourth session (P less than 0.050).« less

Experimental Infection of Rattus norvegicus by the Group II Intermediate Pathogen, Leptospira licerasiae.

PubMed

Fernandez, Carla; Lubar, Aristea A; Vinetz, Joseph M; Matthias, Michael A

2018-06-25

Leptospira licerasiae serovar Varillal, a group II intermediate pathogen species/serovar discovered in the Peruvian Amazon city of Iquitos, is commonly recognized in this region by sera from humans (at least 40% seroprevalence) without a known clinical history of leptospirosis. This high frequency of human seroreactivity remains unexplained. To test the hypothesis that the oral route of infection might explain the high rate of human seroreactivity against L. licerasiae , an experimental infection model using Rattus norvegicus was developed, given that rats were one of the original reservoir hosts identified as being colonized by this leptospire. Sprague-Dawley rats were experimentally exposed via mucosa, direct gastric gavage, or parenteral inoculation with nine different isolates of L. licerasiae originally isolated from Peruvian humans, peridomiciliary rodents, and wildlife. As shown by quantitative polymerase chain reaction of kidney tissue, Leptospira infection via these routes of infection was equally successful. Importantly, the data show that L. licerasiae infects R. norvegicus via the oral route demonstration, leading to renal colonization. Not only do these findings confirm the infectiousness of group II Leptospira , but also they underscore the potential importance of oral as well as mucosal and transcutaneous routes of Leptospira infection.

A comparison between placental and amniotic mesenchymal stem cells for transamniotic stem cell therapy (TRASCET) in experimental spina bifida.

PubMed

Feng, Christina; D Graham, Christopher; Connors, John Patrick; Brazzo, Joseph; Zurakowski, David; Fauza, Dario O

2016-06-01

We compared placental-derived and amniotic fluid-derived mesenchymal stem cells (pMSCs and afMSCs, respectively) in transamniotic stem cell therapy (TRASCET) for experimental spina bifida. Pregnant dams (n=29) exposed to retinoic acid for the induction of fetal spina bifida were divided into four groups. Three groups received volume-matched intraamniotic injections of either saline (n=38 fetuses) or a suspension of 2×10(6) cells/mL of syngeneic, labeled afMSCs (n=73) or pMSCs (n=115) on gestational day 17 (term=21-22days). Untreated fetuses served as controls. Animals were killed before term. Statistical comparisons were by Fisher's exact test (p<0.05). Survival was similar across treatment groups (p=0.08). In fetuses with isolated spina bifida (n=100), there were higher percentages of defect coverage (either partial or complete) in both afMSC and pMSC groups compared with saline and untreated groups (p<0.001-0.03 in pairwise comparisons). There were no differences in coverage rates between afMSC and pMSC groups (p=0.94) or between saline and untreated groups (p=0.98). Both pMSC and afMSC can induce comparable rates of coverage of experimental spina bifida after concentrated intraamniotic injection in the rodent model. This broadens the options for timing and cell source for TRASCET as a potential alternative in the prenatal management of spina bifida. Copyright © 2016 Elsevier Inc. All rights reserved.

Genetic, enzymatic and developmental alterations observed in Caiman latirostris exposed in ovo to pesticide formulations and mixtures in an experiment simulating environmental exposure.

PubMed

Poletta, Gisela L; Kleinsorge, Elisa; Paonessa, Adriana; Mudry, Marta D; Larriera, Alejandro; Siroski, Pablo A

2011-05-01

In South America, economic interests in last years have produced a constant increase in transgenic soybean cropping, with the corresponding rise in pesticide formulated products. The aim of this study was to determine the effects of pesticides formulations and mixtures on a South American caiman, Caiman latirostris, after in ovo exposure. We conducted a field-like experiment which simulates the environmental exposure that a caiman nest can receive in neighbouring croplands habitats. Experimental groups were Control group, Treatment 1: sprayed with a glyphosate herbicide formulation, and Treatment 2: sprayed with a pesticide mixture of glyphosate, endosulfan and cypermethrin formulations. Results demonstrated genotoxicity, enzymatic and metabolic alterations, as well as growth delay in caimans exposed in ovo to Treatments 1 and 2, showing a higher toxicity for the mixture. Integral evaluation through biomarkers of different biological meaning is highly informative as early indicators of contamination with pesticides and mixtures in this wildlife species. Copyright © 2010 Elsevier Inc. All rights reserved.

The Effects of Passive Cigarette Smoke Exposure on the Survival of the Reverse Sural Fasciocutaneous Flap.

PubMed

Sadagatullah, Abdul Nawfar; Halim, Ahmad Sukari; Bathusha, Mohd Shakir; Ramachandran, Anantha Kumar

2017-12-01

Background  The possibility of a person who had undergone surgery to be exposed to the ill effects of cigarette smoke is high, more so if the person lives with a smoker. With increasing popularity of reverse sural fasciocutaneous flaps, a surgeon may have to manage a person who lives with a smoker or is exposed to cigarette smoke. A clear understanding of the effects of exposure to cigarette smoke on reverse sural fasciocutaneous flaps is necessary. This study was performed to establish a clearer understanding of the effects of smoking on reverse sural fasciocutaneous flaps and evidence for preoperative patient counseling about smoking and smoke exposure. Objective  The study investigated effects of exposure to cigarette smoke on the survival of the reverse sural fasciocutaneous flap. Methods  This was an experimental observational study conducted at the Laboratory for Animal Research Unit in the Health Campus of Universiti Sains Malaysia. Twelve adult White New Zealand rabbits ( Oryctolagus cuniculus ) were divided into two groups of six. All 12 rabbits had a 2.5- × 2.5-cm reverse sural fasciocutaneous flap raised on both its hind limbs. The group exposed to cigarette smoke underwent 4 weeks of smoke exposure for 2 hours daily prior to surgery. This was then continued until analysis of the results. The control group had no intervention. All flaps were analyzed on the seventh postoperative day, after tracing on transparent plastic sheets with the necrotic area marked followed by 2D planimetry done on a grid paper. The flaps were assessed on the total flap area and survival area percentage. It was recorded as mean ± SD. The presence or absence of infection and hematoma was also noted. Results  Twelve flaps were analyzed in each group. Total mean flap area and survival area percentage of the control group were 120.33 ± 31.03 mm 2 and 80.12 ± 15.75%, respectively, whereas in the cigarette smoke-exposed group, it was 121.83 ± 17.93 mm 2 and 62.04 ± 34.01%, respectively. The control group had two infections and one hematoma, and the smoking-exposed group had six infections and nine hematomas. The comparison between the groups was made in terms of total flap area, survival percentage, presence of infection, and hematoma for which the p values were 0.886, 0.115, 0.083, and 0.003, respectively. The differences between right and left hind limbs were also analyzed ( p  = 0.414). Conclusion  There was no statistical difference in the results from the right and left hind limbs. There was no statistical difference in the survival of reverse sural fasciocutaneous flap between the control and smoking-exposed groups.

A simple method for comparing immunogold distributions in two or more experimental groups illustrated using GLUT1 labelling of isolated trophoblast cells.

PubMed

Mayhew, T M; Desoye, G

2004-07-01

Colloidal gold-labelling, combined with transmission electron microscopy, is a valuable technique for high-resolution immunolocalization of identified antigens in different subcellular compartments. Whilst the technique has been applied to placental tissues, few quantitative studies have been made. Subcellular compartments exist in three main categories (viz. organelles, membranes, filaments/tubules) and this affects the possibilities for quantification. Generally, gold particles are counted in order to compare either (a) compartments within an experimental group or (b) compartmental labelling distributions between groups. For the former, recent developments make it possible to test whether or not there is differential (nonrandom) labelling of compartments. The methods (relative labelling index and labelling density) are ideally suited to analysing label in one category of compartment (organelle or membrane or filament) but may be adapted to deal with a mixture of categories. They also require information about compartment size (e.g. profile area or trace length). Here, a simple and efficient method for drawing between-group comparisons of labelling distributions is presented. The method does not require information about compartment size or specimen magnification. It relies on multistage random sampling of specimens and unbiased counting of gold particles associated with different compartments. Distributions of observed gold counts in different experimental groups are compared by contingency table analysis with degrees of freedom for chi-squared (chi(2)) values being determined by the numbers of compartments and experimental groups. Compartmental values of chi(2)which contribute substantially to total chi(2)identify the principal subcellular sites of between-group differences. The method is illustrated using datasets from immunolabelling studies on the localization of GLUT1 glucose transporters in cultured human trophoblast cells exposed to different treatments.

[Evaluation of genotoxicity induced by repetitive administration of local anaesthetics: an experimental study in rats].

PubMed

Nai, Gisele Alborghetti; de Oliveira, Mariliza Casanova; de Oliveira Tavares, Graziela; Pereira, Laís Fabrício Fonseca; Soares, Nádia Derli Salvador Lemes; Silva, Patrícia Gatti

2015-01-01

Previous studies regarding the effects of some local anaesthetics have suggested that these agents can cause genetic damage. However, they have not been tested for genotoxicity related to repetitive administration. The aim of this study was to evaluate the genotoxic potential of local anaesthetics upon repetitive administration. 80 male Wistar rats were divided into: group A - 16 rats intraperitoneally injected with lidocaine hydrochloride 2%; group B - 16 rats IP injected with mepivacaine 2%; group C - 16 rats intraperitoneally injected with articaine 4%; group D - 16 rats IP injected with prilocaine 3% (6.0mg/kg); group E - 8 rats subcutaneously injected with a single dose of cyclophosphamide; and group F - 8 rats intraperitoneally injected with saline. Eight rats from groups A to D received a single dose of anaesthetic on Day 1 of the experiment; the remaining rats were dosed once a day for 5 days. The median number of micronuclei in the local anaesthetics groups exposed for 1 or 5 days ranged from 0.00 to 1.00, in the cyclophosphamide-exposed group was 10.00, and the negative control group for 1 and 5 days was 1.00 and 0.00, respectively (p<0.0001). A significant difference in the number of micronuclei was observed between the cyclophosphamide group and all local anaesthetic groups (p=0.0001), but not between the negative control group and the local anaesthetic groups (p>0.05). No genotoxicity effect was observed upon repetitive exposure to any of the local anaesthetics evaluated. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Pathological Evaluation of Natural Cases of a Highly Pathogenic Avian Influenza Virus, Subtype H5N8, in Broiler Breeders and Commercial Layers in South Korea.

PubMed

Bae, Yeon-Ji; Lee, Seung-Baek; Min, Keong-Cheol; Mo, Jong-Suk; Jeon, Eun-Ok; Koo, Bon-Sang; Kwon, Hyeok-Il; Choi, Young Ki; Kim, Jeom-Joo; Kim, Jong-Nyeo; Mo, In-Pil

2015-03-01

Outbreaks of highly pathogenic avian influenza (HPAI) virus, subtype H5N8, were observed in two different flocks of local broiler breeder farms and a commercial layer farm in South Korea. Clinically, the cases were characterized by a gradual increase in mortality, slow transmission, and unrecognizable clinical signs of HPAI. Gross observations in both cases included hemorrhagic or necrotic lesions in internal organs, such as serosal and mucosal membranes, spleen, and pancreas. Both cases exhibited similar histopathologic lesions, including multifocal malacia in the brain and multifocal or diffuse necrosis in the spleen and pancreas. Immunohistochemical results indicated that neurons and glial cells in the brain, myocytes in the heart, acinar cells in the pancreas, and mononuclear phagocytic cells in several visceral organs were immunopositive for avian influenza viral antigen. To experimentally reproduce the low pathogenicity and the mortality observed in these two cases, 18 specific-pathogen-free chickens and 18 commercial layers were divided into an H5N8 virus-inoculated group and a contact-exposed group. The mortality of the chickens in the inoculation group was 50%-100%, whereas the mean time to death was delayed or death did not occur in the contact-exposed group. The distributions of the viral antigens and histopathologic lesions in the experimental study were similar to those observed in the field cases. These findings suggest that the H5N8 virus induces a different pattern of pathobiology, including slow transmission and low mortality, compared with that of other HPAI viruses. This is the first pathologic description of natural cases of H5N8 in South Korea, and it may be helpful in understanding the pathobiology of novel H5N8 HPAI viruses.

Evaluating effectiveness of dynamic soundfield system in the classroom.

PubMed

da Cruz, Aline Duarte; Alves Silvério, Kelly Cristina; Da Costa, Aline Roberta Aceituno; Moret, Adriane Lima Mortari; Lauris, José Roberto Pereira; de Souza Jacob, Regina Tangerino

2016-01-01

Research has reported on the use of soundfield amplification devices in the classroom. However, no study has used standardized tests to determine the potential advantages of the dynamic soundfield system for normally hearing students and for the teacher's voice. Our aim was to evaluate the impact of using dynamic soundfield system on the noise of the classroom, teacher's voice and students' academic performance. This was a prospective cohort study in which 20 student participants enrolled in the third year of basic education were divided into two groups (i.e., control and experimental); their teacher participated. The experimental group was exposed to the dynamic soundfield system for 3 consecutive months. The groups were assessed using standardized tests to evaluate their academic performance. Further, questionnaires and statements were collected on the participants' experience of using the soundfield system. We statistically analyzed the results to compare the academic performance of the control group with that of the experimental group. In all cases, a significance level of P < .05 was adopted. Use of the dynamic soundfield system was effective for improving the students' academic performance on standardized tests for reading, improving the teacher's speech intelligibility, and reducing the teacher's vocal strain. The dynamic soundfield system minimizes the impact of noise in the classroom as demonstrated by the mensuration of the signal-to-noise ratio (SNR) and pupil performance on standardized tests for reading and student and teacher ratings of amplification system effectiveness.

Controlled Low-Pressure Blast-Wave Exposure Causes Distinct Behavioral and Morphological Responses Modelling Mild Traumatic Brain Injury, Post-Traumatic Stress Disorder, and Comorbid Mild Traumatic Brain Injury-Post-Traumatic Stress Disorder.

PubMed

Zuckerman, Amitai; Ram, Omri; Ifergane, Gal; Matar, Michael A; Sagi, Ram; Ostfeld, Ishay; Hoffman, Jay R; Kaplan, Zeev; Sadot, Oren; Cohen, Hagit

2017-01-01

The intense focus in the clinical literature on the mental and neurocognitive sequelae of explosive blast-wave exposure, especially when comorbid with post-traumatic stress-related disorders (PTSD) is justified, and warrants the design of translationally valid animal studies to provide valid complementary basic data. We employed a controlled experimental blast-wave paradigm in which unanesthetized animals were exposed to visual, auditory, olfactory, and tactile effects of an explosive blast-wave produced by exploding a thin copper wire. By combining cognitive-behavioral paradigms and ex vivo brain MRI to assess mild traumatic brain injury (mTBI) phenotype with a validated behavioral model for PTSD, complemented by morphological assessments, this study sought to examine our ability to evaluate the biobehavioral effects of low-intensity blast overpressure on rats, in a translationally valid manner. There were no significant differences between blast- and sham-exposed rats on motor coordination and strength, or sensory function. Whereas most male rats exposed to the blast-wave displayed normal behavioral and cognitive responses, 23.6% of the rats displayed a significant retardation of spatial learning acquisition, fulfilling criteria for mTBI-like responses. In addition, 5.4% of the blast-exposed animals displayed an extreme response in the behavioral tasks used to define PTSD-like criteria, whereas 10.9% of the rats developed both long-lasting and progressively worsening behavioral and cognitive "symptoms," suggesting comorbid PTSD-mTBI-like behavioral and cognitive response patterns. Neither group displayed changes on MRI. Exposure to experimental blast-wave elicited distinct behavioral and morphological responses modelling mTBI-like, PTSD-like, and comorbid mTBI-PTSD-like responses. This experimental animal model can be a useful tool for elucidating neurobiological mechanisms underlying the effects of blast-wave-induced mTBI and PTSD and comorbid mTBI-PTSD.

The maturation state of the auditory nerve and brainstem in rats exposed to lead acetate and supplemented with ferrous sulfate.

PubMed

Zucki, Fernanda; Morata, Thais C; Duarte, Josilene L; Ferreira, Maria Cecília F; Salgado, Manoel H; Alvarenga, Kátia F

The literature has reported the association between lead and auditory effects, based on clinical and experimental studies. However, there is no consensus regarding the effects of lead in the auditory system, or its correlation with the concentration of the metal in the blood. To investigate the maturation state of the auditory system, specifically the auditory nerve and brainstem, in rats exposed to lead acetate and supplemented with ferrous sulfate. 30 weanling male rats (Rattus norvegicus, Wistar) were distributed into six groups of five animals each and exposed to one of two concentrations of lead acetate (100 or 400mg/L) and supplemented with ferrous sulfate (20mg/kg). The maturation state of the auditory nerve and brainstem was analyzed using Brainstem Auditory Evoked Potential before and after lead exposure. The concentration of lead in blood and brainstem was analyzed using Inductively Coupled Plasma-Mass Spectrometry. We verified that the concentration of Pb in blood and in brainstem presented a high correlation (r=0.951; p<0.0001). Both concentrations of lead acetate affected the maturation state of the auditory system, being the maturation slower in the regions corresponding to portion of the auditory nerve (wave I) and cochlear nuclei (wave II). The ferrous sulfate supplementation reduced significantly the concentration of lead in blood and brainstem for the group exposed to the lowest concentration of lead (100mg/L), but not for the group exposed to the higher concentration (400mg/L). This study indicate that the lead acetate can have deleterious effects on the maturation of the auditory nerve and brainstem (cochlear nucleus region), as detected by the Brainstem Auditory Evoked Potentials, and the ferrous sulphate can partially amend this effect. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. All rights reserved.

Effect of acupressure on fatigue in women with multiple sclerosis.

PubMed

Bastani, Farideh; Sobhani, Marzie; Emamzadeh Ghasemi, Hormat Sadat

2015-01-26

Multiple sclerosis (MS) is the most common cause of progressive neurological disability. The prevalence of MS is much more common in women than men. The women are exposed to a variety of symptoms including fatigue. Acupressure is a noninvasive procedure that can be used to control symptoms including fatigue. The aim of the study was to evaluate the effect of acupressure on fatigue in women with multiple sclerosis. A randomized clinical trial was conducted on 100 women with MS at Tehran MS Association. The subjects were equally allocated to experimental group and a placebo group (50 women per group) by blocking randomization method. The experimental group were received acupressure, at the true points (ST36, SP6, LI4) and the placebo group, were received touching at the same points. Fatigue was measured by a Fatigue Severity Scale (FSS) in the groups at immediately prior to, two and four weeks after the beginning of the intervention. The data was analyzed using descriptive and inferential statistics by SPSS version 17. The findings indicated no differences in demographic characteristics and the severity of fatigue at the baseline in two groups (p=0.54). But there were significant reductions of the mean score of fatigue in the experimental group compared to the placebo group immediately, two and four weeks after the intervention respectively (p=0.03, p?0/001, p=0.04). According to the findings, the study provided an alternative method for health care providers including nurses to train acupressure to the clients with MS to managing their fatigue.

The influence of powdered coconut water (ACP-318®) in in vitro maturation of canine oocytes.

PubMed

Silva, A E F; Cavalcante, L F; Rodrigues, B A; Rodrigues, J L

2010-12-01

The objective of this study was to determine the influence of powdered coconut water (ACP-318(®)) diluted in high glucose (11.0 mM) TCM199 in the achievement of nuclear in vitro maturation (IVM) of canine oocytes. Cumulus oocyte complexes (COCs) (n = 632) were randomly allocated into three experimental groups named as group 1 (control group), group 2 (5% powdered coconut water) and group 3 (10% powdered coconut water). The percentage of meiotic resumption (MR) (GVBD to MII) was 39.1% (81/207), 50.2% (108/215) and 46.6% (98/210) for groups 1, 2 and 3 respectively (p < 0.05). There were no differences in MR rates among groups 2 and 3. The medium with ACP-318(®) slightly enhanced the nuclear maturation of canine oocytes when a comparison was established with rates of maturation exhibited by oocytes in the experimental group 1 without ACP-318(®) (p < 0.05). The results suggest that oocytes' nuclear morphology integrity and meiosis achievement were positively influenced when exposed to high glucose TCM199 supplemented with 5% powdered coconut water. Further investigation must be performed for a better understanding of powdered coconut water influence in cellular events during IVM of dog oocytes. © 2009 Blackwell Verlag GmbH.

Simulated in vivo Electrophysiology Experiments Provide Previously Inaccessible Insights into Visual Physiology

PubMed Central

Quiroga, Maria del Mar; Price, Nicholas SC

2016-01-01

Lecture content and practical laboratory classes are ideally complementary. However, the types of experiments that have led to our detailed understanding of sensory neuroscience are often not amenable to classroom experimentation as they require expensive equipment, time-consuming surgeries, specialized experimental techniques, and the use of animals. While sometimes feasible in small group teaching, these experiments are not suitable for large cohorts of students. Previous attempts to expose students to sensory neuroscience experiments include: the use of electrophysiology preparations in invertebrates, data-driven simulations that do not replicate the experience of conducting an experiment, or simply observing an experiment in a research laboratory. We developed an online simulation of a visual neuroscience experiment in which extracellular recordings are made from a motion sensitive neuron. Students have control over stimulation parameters (direction and contrast) and can see and hear the action potential responses to stimuli as they are presented. The simulation provides an intuitive way for students to gain insight into neurophysiology, including experimental design, data collection and data analysis. Our simulation allows large cohorts of students to cost-effectively “experience” the results of animal research without ethical concerns, to be exposed to realistic data variability, and to develop their understanding of how sensory neuroscience experiments are conducted. PMID:27980465

School Context and Educational Outcomes: Results from a Quasi-Experimental Study

PubMed Central

Casciano, Rebecca; Massey, Douglas S.

2013-01-01

In this study we draw on data from a quasi-experimental study to test whether moving into a subsidized housing development in an affluent suburb yields educational benefits to the children of residents, compared to the educations they would have received had they not moved into the development. Results suggest that resident children experienced a significant improvement in school quality compared with a comparison group of students whose parents also had applied for residence. Parents who were residents of the development also displayed higher levels of school involvement compared with the comparison group of non-resident parents, and their children were exposed to significantly lower levels of school disorder and violence within school and spent more time reading outside of school. Living in the development did not influence GPA directly, but did indirectly increase GPA by increasing the time residents spent reading outside of school. PMID:25342878

Differential Impact of Message Appeals, Food Healthiness, and Poverty Status on Evaluative Responses to Nutrient-Content Claimed Food Advertisements.

PubMed

Choi, Hojoon; Reid, Leonard N

2015-01-01

A 2 × 3 × 2 mixed factorial experimental design was used to examine how three message appeals (benefit-seeking vs. risk-avoidance vs. taste appeals), food healthiness (healthy vs. unhealthy foods), and consumer poverty status (poverty vs. nonpoverty groups) impact evaluative responses to nutrient-content claimed food advertisements. Subjects were partitioned into two groups, those below and those above the poverty line, and exposed to nutrient-content claimed advertisement treatments for healthy and unhealthy foods featuring the three appeals. The findings reaffirmed the interaction effects between perceivably healthy and unhealthy foods and different appeals reported in previous studies, and found interaction effects between consumer poverty level and response to the message appeals featured in the experimental food advertisements. Age, body mass index, current dieting status, education, and gender were examined as covariates.

Performance of the first Japanese large-scale facility for radon inhalation experiments with small animals.

PubMed

Ishimori, Yuu; Mitsunobu, Fumihiro; Yamaoka, Kiyonori; Tanaka, Hiroshi; Kataoka, Takahiro; Sakoda, Akihiro

2011-07-01

A radon test facility for small animals was developed in order to increase the statistical validity of differences of the biological response in various radon environments. This paper illustrates the performances of that facility, the first large-scale facility of its kind in Japan. The facility has a capability to conduct approximately 150 mouse-scale tests at the same time. The apparatus for exposing small animals to radon has six animal chamber groups with five independent cages each. Different radon concentrations in each animal chamber group are available. Because the first target of this study is to examine the in vivo behaviour of radon and its effects, the major functions to control radon and to eliminate thoron were examined experimentally. Additionally, radon progeny concentrations and their particle size distributions in the cages were also examined experimentally to be considered in future projects.

Project Clarion: Three Years of Science Instruction in Title I Schools among K-Third Grade Students

NASA Astrophysics Data System (ADS)

Kim, Kyung Hee; VanTassel-Baska, Joyce; Bracken, Bruce A.; Feng, Annie; Stambaugh, Tamra; Bland, Lori

2012-10-01

The purpose of the study was to measure the effects of higher level, inquiry-based science curricula on students at primary level in Title I schools. Approximately 3,300 K-3 students from six schools were assigned to experimental or control classes ( N = 115 total) on a random basis according to class. Experimental students were exposed to concept-based science curriculum that emphasized `deep learning' though concept mastery and investigation, whereas control classes learned science from traditional school-based curricula. Two ability measures, the Bracken Basic Concept Scale-Revised (BBCS-R, Bracken 1998) and the Naglieri Nonverbal Intelligence Test (NNAT, Naglieri 1991), were used for baseline information. Additionally, a standardized measure of student achievement in science (the MAT-8 science subtest), a standardized measure of critical thinking, and a measure for observing teachers' classroom behaviors were used to assess learning outcomes. Results indicated that all ability groups of students benefited from the science inquiry-based approach to learning that emphasized science concepts, and that there was a positive achievement effect for low socio-economic young children who were exposed to such a curriculum.

A study of professional radiation hazards in CT scan and nuclear medicine workers using GTG-banding and solid stain.

PubMed

Changizi, Vahid; Alizadeh, Mohammad Hossein; Mousavi, Akbar

2015-01-01

CT scan and nuclear medicine exams deliver a great part of medical exposures. This study examined professional radiation hazards in CT scan and nuclear medicine workers. In a cross sectional study 30 occupationally exposed workers and 7 controls (all from personnel of a laboratory) were selected. Physical dosimetry was performed for exposed workers. Blood samples were obtained from the experimental and control groups. Three culture mediums for each one were prepared in due to routine chromosome analysis using G-banding and solid stain. There were significant increased incidence of chromatid gap (ctg) and chromatid break (ctb) with mean±SD frequencies of 3±0.84 and 3.1±1.40 per 100 cells respectively in the nuclear medicine workers versus controls with mean±SD frequencies of 1.9±0.69 and 1.3±0.84 for ctg and ctb, respectively. Chromosome gaps (chrg) were higher significantly in the nuclear medicine population (2.47±0.91) than in controls (1.4±0.9) (p< 0.05). In CT scan group the ctg and ctb were increased with a mean±SD frequency of 2.7±0.79 and 2.6±0.91 per 100 cells respectively compared with control group. The mean±SD frequencies of the chrb were 2.0±0.75 and 0.86±0.690 per 100 cells for exposed workers and control group, respectively. This study showed chromosome aberrations in peripheral lymphocytes using solid stain method are reasonable biomarker reflecting personnel radiation damage.

Effect of radiofrequency radiation from Wi-Fi devices on mercury release from amalgam restorations.

PubMed

Paknahad, Maryam; Mortazavi, S M J; Shahidi, Shoaleh; Mortazavi, Ghazal; Haghani, Masoud

2016-01-01

Dental amalgam is composed of approximately 50% elemental mercury. Despite concerns over the toxicity of mercury, amalgam is still the most widely used restorative material. Wi-Fi is a rapidly using local area wireless computer networking technology. To the best of our knowledge, this is the first study that evaluates the effect of exposure to Wi-Fi signals on mercury release from amalgam restorations. Standard class V cavities were prepared on the buccal surfaces of 20 non-carious extracted human premolars. The teeth were randomly divided into 2 groups (n = 10). The control group was stored in non-environment. The specimens in the experimental groups were exposed to a radiofrequency radiation emitted from standard Wi Fi devices at 2.4 GHz for 20 min. The distance between the Wi-Fi router and samples was 30 cm and the router was exchanging data with a laptop computer that was placed 20 m away from the router. The concentration of mercury in the artificial saliva in the groups was evaluated by using a cold-vapor atomic absorption Mercury Analyzer System. The independent t test was used to evaluate any significant differences in mercury release between the two groups. The mean (±SD) concentration of mercury in the artificial saliva of the Wi-Fi exposed teeth samples was 0.056 ± .025 mg/L, while it was only 0.026 ± .008 mg/L in the non-exposed control samples. This difference was statistically significant (P =0.009). Exposure of patients with amalgam restorations to radiofrequency radiation emitted from conventional Wi-Fi devices can increase mercury release from amalgam restorations.

[The effect of potable mineral waters on the hormonal and psychological status (experimental and clinical research)].

PubMed

Polushina, N D; Babina, L M; Shvedunova, L N

1994-01-01

Experiments on 80 Wistar rats revealed the ability of Essentuki mineral waters to stimulate the reserves and sensitivity of the intestinal serotonin-producing system. A clinical trial on two groups of children (exposed to low-dose ionizing radiation or with posttraumatic astheno-neurotic syndrome) found out pronounced positive changes in the psychological status of the children which progressed in correlation with an increase of the blood serotonin levels.

Relationship of drinking water disinfectants to plasma cholesterol and thyroid hormone levels in experimental studies.

PubMed Central

Revis, N W; McCauley, P; Bull, R; Holdsworth, G

1986-01-01

The effects of drinking water containing 2 or 15 ppm chlorine (pH 6.5 and 8.5), chlorine dioxide, and monochloramine on thyroid function and plasma cholesterol were studied because previous investigators have reported cardiovascular abnormalities in experimental animals exposed to chlorinated water. Plasma thyroxine (T4) levels, as compared to controls, were significantly decreased in pigeons fed a normal or high-cholesterol diet and drinking water containing these drinking water disinfectants at a concentration of 15 ppm (the exception was chlorine at pH 6.5) for 3 months. In most of the treatment groups, T4 levels were significantly lower following the exposure to drinking water containing the 2 ppm dose. Increases in plasma cholesterol were frequently observed in the groups with lower T4 levels. This association was most evident in pigeons fed the high-cholesterol diet and exposed to these disinfectants at a dose of 15 ppm. For example, after 3 months of exposure to deionized water or water containing 15 ppm monochloramine, plasma cholesterol was 1266 +/- 172 and 2049 +/- 212 mg/dl, respectively, a difference of 783 mg/dl. The factor(s) associated with the effect of these disinfectants on plasma T4 and cholesterol is not known. We suggest however that these effects are probably mediated by products formed when these disinfectants react with organic matter in the upper gastrointestinal tract. PMID:3456597

Estuarine sediment toxicity tests on diatoms: Sensitivity comparison for three species

NASA Astrophysics Data System (ADS)

Moreno-Garrido, Ignacio; Lubián, Luis M.; Jiménez, Begoña; Soares, Amadeu M. V. M.; Blasco, Julián

2007-01-01

Experimental populations of three marine and estuarine diatoms were exposed to sediments with different levels of pollutants, collected from the Aveiro Lagoon (NW of Portugal). The species selected were Cylindrotheca closterium, Phaeodactylum tricornutum and Navicula sp. Previous experiments were designed to determine the influence of the sediment particle size distribution on growth of the species assayed. Percentage of silt-sized sediment affect to growth of the selected species in the experimental conditions: the higher percentage of silt-sized sediment, the lower growth. In any case, percentages of silt-sized sediment less than 10% did not affect growth. In general, C. closterium seems to be slightly more sensitive to the selected sediments than the other two species. Two groups of sediment samples were determined as a function of the general response of the exposed microalgal populations: three of the six samples used were more toxic than the other three. Chemical analysis of the samples was carried out in order to determine the specific cause of differences in toxicity. After a statistical analysis, concentrations of Sn, Zn, Hg, Cu and Cr (among all physico-chemical analyzed parameters), in order of importance, were the most important factors that divided the two groups of samples (more and less toxic samples). Benthic diatoms seem to be sensitive organisms in sediment toxicity tests. Toxicity data from bioassays involving microphytobentos should be taken into account when environmental risks are calculated.

Organochlorine-induced histopathology in kidney and liver tissue from Arctic fox (Vulpes lagopus).

PubMed

Sonne, Christian; Wolkers, Hans; Leifsson, Pall S; Jenssen, Bjørn Munro; Fuglei, Eva; Ahlstrøm, Oystein; Dietz, Rune; Kirkegaard, Maja; Muir, Derek C G; Jørgensen, Even

2008-04-01

The effects of persistent organic pollutants on renal and liver morphology in farmed arctic fox (Vulpes lagopus) were studied under experimental conditions. Control animals received a diet containing pork (Sus scrofa) fat with low amounts of persistent organic pollutants, while the diet of the exposed animals contained whale blubber, 'naturally' contaminated with persistent organic pollutants. Polychlorinated biphenyls (PCB) and organochlorine pesticide (OCP) concentrations in the whale blubber were 488 and 395 ng/g wet weight, respectively. Animals were sacrificed and sampled when they were at their fattest (winter) as well as their lowest body weight (summer). The results show that PCB and OCP exposure causes renal (and probably also liver) lesions in arctic foxes. The prevalence of glomerular, tubular and interstitial lesions was significantly highest in the exposed group (chi-square: all p<0.05). The frequency of liver lesions (steatosis, intravascular granulocyte accumulations, interstitial cell infiltrations, lipid granulomas, portal fibrosis and bile duct hyperplasia) were also highest in the exposed group, although not significantly (chi-square: all p>0.05). The prevalence of lesions was not significantly different between lean (winter) and fat (summer) foxes for any of the lesions (chi-square: all p>0.05). We suggest that wild arctic foxes exposed to an environmental cocktail of persistent organic pollutants, such as PCBs and OCPs, in their natural diet are at risk for developing chronic kidney and liver damage. Whether such lesions may have an impact on age and health of the animals remains uncertain.

[A survey of occupational health among polyether-exposed workers].

PubMed

Fu, Xu-ying; Yu, Bin; Zhang, Chun-ping; Zheng, Guan-hua; Bai, Lan; Zhang, Pan-pan

2013-06-01

To investigate the occupational health of the workers simultaneously exposed to acrylonitrile, epoxyethane, epoxypropane, and styrene. A questionnaire survey was conducted in 70 front-line workers simultaneously exposed to acrylonitrile, epoxyethane, epoxypropane, and styrene (exposure group) and 50 managers (control group) in a polyether manufacturer; in addition, air monitoring at workplace and occupational health examination were also performed. The obtained data were analyzed. The female workers in exposure group and the spouses of male workers in exposure group had significantly higher spontaneous abortion rates than their counterparts in control group (P < 0.01). The exposure group had a significantly higher abnormal rate of blood urea nitrogen than the control group (P < 0.01). The workers with different polyether-exposed working years had significantly higher mean levels of DNA damage than the control group (P < 0.01); the workers with not less than 5 and less than 20 polyether-exposed working years and those with not less than 20 polyether-exposed working years had significantly higher mean micronucleus rates than the control group (P < 0.01); there were no significant differences in overall chromosome aberration rate and mean level of DNA damage between each two groups of workers with different polyether-exposed working years (P > 0.05); the workers with not less than 5 and less than 20 polyether-exposed working years and workers with not less than 20 polyether-exposed working years had significantly higher mean micronucleus rates than those with less than 5 polyether-exposed working years (P < 0.01). Simultaneous exposure to acrylonitrile, epoxyethane, epoxypropane, and styrene causes occupational hazards among the workers in polyether manufacturer.

The effects of concept and vee mappings under three learning modes on Jamaican eighth graders' knowledge of nutrition and plant reproduction

NASA Astrophysics Data System (ADS)

Ugwu, Okechukwu; Soyibo, Kola

2004-01-01

The first objective of this study was to investigate if the experimental students' post-test knowledge of nutrition and plant reproduction would be improved more significantly than that of their control group counterparts based on their treatment, attitudes to science, self-esteem, gender and socio-economic background. Treatment involved teaching the experimental students under three learning modes--pure cooperative, cooperative-competitive and individualistic whole class interpersonal competitive condition--using concept and vee mappings and the lecture method. The control groups received the same treatment but were not exposed to concept and vee mappings. This study's second objective was to determine which of the three learning modes would produce the highest post-test mean gain in the subjects' knowledge of the two biology concepts. The study's sample comprised 932 eighth graders (12-13-year-olds) in 14 co-educational comprehensive high schools randomly selected from two Jamaican parishes. An integrated science performance test, an attitudes to science questionnaire and a self-esteem questionnaire were used to collect data. The results indicated that the experimental students (a) under the three learning modes, (b) with high, moderate, and low attitudes to science, and (c) with high, moderate, and low self-esteem, performed significantly better than their control group counterparts. The individualist whole class learning mode engendered the highest mean gain on the experimental students' knowledge, while the cooperative-competitive learning mode generated the highest mean gain for the control group students.

Opposing effects of allogrooming on disease transmission in ant societies

PubMed Central

Theis, Fabian J.; Ugelvig, Line V.; Marr, Carsten; Cremer, Sylvia

2015-01-01

To prevent epidemics, insect societies have evolved collective disease defences that are highly effective at curing exposed individuals and limiting disease transmission to healthy group members. Grooming is an important sanitary behaviour—either performed towards oneself (self-grooming) or towards others (allogrooming)—to remove infectious agents from the body surface of exposed individuals, but at the risk of disease contraction by the groomer. We use garden ants (Lasius neglectus) and the fungal pathogen Metarhizium as a model system to study how pathogen presence affects self-grooming and allogrooming between exposed and healthy individuals. We develop an epidemiological SIS model to explore how experimentally observed grooming patterns affect disease spread within the colony, thereby providing a direct link between the expression and direction of sanitary behaviours, and their effects on colony-level epidemiology. We find that fungus-exposed ants increase self-grooming, while simultaneously decreasing allogrooming. This behavioural modulation seems universally adaptive and is predicted to contain disease spread in a great variety of host–pathogen systems. In contrast, allogrooming directed towards pathogen-exposed individuals might both increase and decrease disease risk. Our model reveals that the effect of allogrooming depends on the balance between pathogen infectiousness and efficiency of social host defences, which are likely to vary across host–pathogen systems. PMID:25870394

Co-housing of Rift Valley Fever Virus Infected Lambs with Immunocompetent or Immunosuppressed Lambs Does Not Result in Virus Transmission

PubMed Central

Wichgers Schreur, Paul J.; van Keulen, Lucien; Kant, Jet; Oreshkova, Nadia; Moormann, Rob J. M.; Kortekaas, Jeroen

2016-01-01

Rift Valley fever virus (RVFV) is transmitted among susceptible animals by mosquito vectors. Although the virus can be isolated from nasal and oral swabs of infected animals and is known to be highly infectious when administered experimentally via oral or respiratory route, horizontal transmission of the virus is only sporadically reported in literature. We considered that immunosuppression resulting from stressful conditions in the field may increase the susceptibility to horizontally transmitted RVFV. Additionally, we reasoned that horizontal transmission may induce immune responses that could affect the susceptibility of contact-exposed animals to subsequent infection via mosquito vectors. To address these two hypotheses, viremic lambs were brought into contact with sentinel lambs. One group of sentinel lambs was treated with the immunosuppressive synthetic glucocorticosteroid dexamethasone and monitored for signs of disease and presence of virus in the blood and target organs. Another group of contact-exposed sentinel lambs remained untreated for three weeks and was subsequently challenged with RVFV. We found that none of the dexamethasone-treated contact-exposed lambs developed detectable viremia, antibody responses or significant increases in cytokine mRNA levels. Susceptibility of immunocompetent lambs to RVFV infection was not influenced by previous contact-exposure. Our results are discussed in light of previous findings. PMID:27014211

Biochemical and histological studies on adverse effects of mobile phone radiation on rat's brain.

PubMed

Hussein, Shaymaa; El-Saba, Abdel-Aleem; Galal, Mona K

2016-12-01

With the rapid development of electronic technologies, the public concern about the potential health hazards induced by radiofrequency (RF) radiation has been grown. To investigate the effect of 1800MHz RF radiation emitted from mobile phone on the rat's brain, the present study was performed. Forty male rats were randomly divided into two equal groups; control and exposed group. The later one exposed to 1800MHz emitted from mobile phone with an SAR value of 0.6W/kg for two hours/day for three months. The brain tissues were collected at the end of the experimental period and separated into hippocampus and cerebellum for subsequent biochemical, histological, immunohistochemical and electron microscopic investigations. The rats that were exposed to RF- radiation had a significant elevation in MDA content and a significant reduction in antioxidant parameters (glutathione, super oxide dismutase and glutathione peroxidase) in both regions. Degenerative changes were observed in the hippocampus pyramidal cells, dark cells and cerebellar Purkinje cells with vascular congestion. In addition a significant DNA fragmentation and over expression of cyclooxygenase-2 apoptotic gene was detected. Those results suggested that, direct chronic exposure to mobile phone caused severe biochemical and histopathological changes in the brain. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of ELF magnetic fields on lipid peroxidation, sperm count, p53, and trace elements.

PubMed

Akdag, M Zulkuf; Dasdag, Suleyman; Aksen, Feyzan; Isik, Birgul; Yilmaz, Fahri

2006-11-01

Some epidemiological and laboratory studies suggest a possible connection between extremely low-frequency (ELF) magnetic fields and certain illnesses, such as cancer, immune suppression, as well as reproductive toxic effects and abnormalities. Therefore, the aim of this study was to investigate the effects of ELF magnetic fields (1.35 mT) on sperm count, malondialdehyde concentration, the histology of such organs as the testes, brain, liver, and kidney tissues, p53 immunoreactivity of bone marrow, and the serum concentrations of Cu2+, Zn2+, Mn2+, and Fe3+ in rats. Sixteen Sprague-Dawley male rats were divided into two groups. The rats in the experimental group were exposed to an ELF magnetic field 2 hr/day for 2 months (7 days a week). The rats in the control group were not exposed to the ELF magnetic field. The exposure was performed in a Faraday cage (130 x 65 x 80 cm) with grounded shielding against the electric component. The Mann-Whitney U-test was used for the statistical analysis of the data. Magnetic field measurements showed that, under the experimental conditions, the magnetic field-exposure system produced a stable flux density of 1.35+/-0.018 mT and a stable frequency of 50 Hz, with negligible harmonics and no transients. However, no statistically significant alteration was observed in the parameters measured in this study except in Mn2+ concentrations (p<0.001). The present study found no evidence of an adverse effect of ELF magnetic fields on the measured parameters except for significantly increased Mn2+ concentrations (p<0.001).

Long-Term Effects of Stem Cells on Total-Body Irradiated Mice

NASA Astrophysics Data System (ADS)

Vyalkina, M. V.; Alchinova, I. B.; Yakovenko, E. N.; Medvedeva, Yu S.; Saburina, I. N.; Karganov, M. Yu

2017-01-01

C57Bl/6 mice were exposed to γ-radiation in a sublethal dose of 7.5 Gy. In 3 hours injection 106/mouse of bone marrow multipotent mesenchymal stromal cells stem cells intravenously to experimental group was done. Methods used: body weight measurement, open field behavior, subfraction composition of blood serum (laser correlation spectroscopy, LCS), histological examination of the spleen, liver, and pancreas, count of T and B cells, white blood formula. After 1.5 and 3 months the general trend towards intermediate position of the parameters observed in the experimental between those in intact and irradiated controls attests to partial protective/restorative effects of the injected cells.

Retrospective estimation of the electric and magnetic field exposure conditions in in vitro experimental reports reveal considerable potential for uncertainty.

PubMed

Portelli, Lucas A; Falldorf, Karsten; Thuróczy, György; Cuppen, Jan

2018-04-01

Experiments on cell cultures exposed to extremely low frequency (ELF, 3-300 Hz) magnetic fields are often subject to multiple sources of uncertainty associated with specific electric and magnetic field exposure conditions. Here we systemically quantify these uncertainties based on exposure conditions described in a group of bioelectromagnetic experimental reports for a representative sampling of the existing literature. The resulting uncertainties, stemming from insufficient, ambiguous, or erroneous description, design, implementation, or validation of the experimental methods and systems, were often substantial enough to potentially make any successful reproduction of the original experimental conditions difficult or impossible. Without making any assumption about the true biological relevance of ELF electric and magnetic fields, these findings suggest another contributing factor which may add to the overall variability and irreproducibility traditionally associated with experimental results of in vitro exposures to low-level ELF magnetic fields. Bioelectromagnetics. 39:231-243, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Effects of Music Therapy on the Cardiovascular and Autonomic Nervous System in Stress-Induced University Students: A Randomized Controlled Trial.

PubMed

Lee, Kyoung Soon; Jeong, Hyeon Cheol; Yim, Jong Eun; Jeon, Mi Yang

2016-01-01

Stress is caused when a particular relationship between the individual and the environment emerges. Specifically, stress occurs when an individual's abilities are challenged or when one's well-being is threatened by excessive environmental demands. The aim of this study was to measure the effects of music therapy on stress in university students. Randomized controlled trial. Sixty-four students were randomly assigned to the experimental group (n = 33) or the control group (n = 31). Music therapy. Initial measurement included cardiovascular indicators (blood pressure and pulse), autonomic nervous activity (standard deviation of the normal-to-normal intervals [SDNN], normalized low frequency, normalized high frequency, low/high frequency), and subjective stress. After the first measurement, participants in both groups were exposed to a series of stressful tasks, and then a second measurement was conducted. The experimental group then listened to music for 20 minutes and the control group rested for 20 minutes. A third and final measurement was then taken. There were no significant differences between the two groups in the first or second measurement. However, after music therapy, the experimental group and the control group showed significant differences in all variables, including systolic blood pressure (p = .026), diastolic blood pressure (p = .037), pulse (p < .001), SDNN (p = .003), normalized low frequency (p < .001), normalized high frequency (p = .010), and subjective stress (p = .026). Classical music tends to relax the body and may stimulate the parasympathetic nervous system. These results suggest music therapy as an intervention for stress reduction.

Blue-light filtering alters angiogenic signaling in human retinal pigmented epithelial cells culture model.

PubMed

Vila, Natalia; Siblini, Aya; Esposito, Evangelina; Bravo-Filho, Vasco; Zoroquiain, Pablo; Aldrees, Sultan; Logan, Patrick; Arias, Lluis; Burnier, Miguel N

2017-11-02

Light exposure and more specifically the spectrum of blue light contribute to the oxidative stress in Age-related macular degeneration (AMD). The purpose of the study was to establish whether blue light filtering could modify proangiogenic signaling produced by retinal pigmented epithelial (RPE) cells under different conditions simulating risk factors for AMD. Three experiments were carried out in order to expose ARPE-19 cells to white light for 48 h with and without blue light-blocking filters (BLF) in different conditions. In each experiment one group was exposed to light with no BLF protection, a second group was exposed to light with BLF protection, and a control group was not exposed to light. The ARPE-19 cells used in each experiment prior to light exposure were cultured for 24 h as follows: Experiment 1) Normoxia, Experiment 2) Hypoxia, and Experiment 3) Lutein supplemented media in normoxia. The media of all groups was harvested after light exposure for sandwich ELISA-based assays to quantify 10 pro-angiogenic cytokines. A significant decrease in angiogenin secretion levels and a significant increase in bFGF were observed following light exposure, compared to dark conditions, in both normoxia and hypoxia conditions. With the addition of a blue light-blocking filter in normoxia, a significant increase in angiogenin levels was observed. Although statistical significance was not achieved, blue light filters reduce light-induced secretion of bFGF and VEGF to near normal levels. This trend is also observed when ARPE-19 cells are grown under hypoxic conditions and when pre-treated with lutein prior to exposure to experimental conditions. Following light exposure, there is a decrease in angiogenin secretion by ARPE-19 cells, which was abrogated with a blue light - blocking filter. Our findings support the position that blue light filtering affects the secretion of angiogenic factors by retinal pigmented epithelial cells under normoxic, hypoxic, and lutein-pretreated conditions in a similar manner.

Schistosoma haematobium infection in the opossom (Didelphis marsupialis): involvement of the urogenital system*

PubMed Central

Kuntz, Robert E.; Myers, Betty June; Cheever, Allen W.

1971-01-01

Investigations of experimental schistosomiasis haematobia have suffered for want of satisfactory mammals in which schistosome infections would establish host—parasite situations more or less comparable with those seen in man. As a consequence, mammals representing different major groups have been exposed to infection by Schistosoma haematobium (Iran strain) to determine their potential use as models for more detailed investigations. In preliminary studies, 8 American opossums (Didelphis marsupialis) were exposed to 1000 or 2000 cercariae. Macroscopic involvement of the urogenital tract was noted in 3 animals, one of which had a 1-cm fibrous plaque in the bladder. In another animal, multiple transitional cell papillomas were present in the bladder and in one ureter. ImagesFig. 3Fig. 4Fig. 7Fig. 8Fig. 5Fig. 6Fig. 2 PMID:5316850

Field validation of experimental challenge models for IPN vaccines.

PubMed

Ramstad, A; Romstad, A B; Knappskog, D H; Midtlyng, P J

2007-12-01

Atlantic salmon S1/2 pre-smolts from the VESO Vikan hatchery were assigned to study groups, i.p. immunized with commercially available, multivalent oil-adjuvanted vaccines with (Norvax Compact 6 - NC-6) or without (Norvax Compact 4 - NC-4) recombinant infectious pancreatic necrosis virus (IPNV) antigen. A control group received saline solution. When ready for sea, the fish were transported to the VESO Vikan experimental laboratory, where two identical tanks were stocked with 75 fish per group before being transferred to 10 degrees C sea water and exposed by bath to first passage IPNV grown in CHSE-214 cells. The third tank containing 40 fish from each group was challenged by the introduction of 116 fish that had received an i.p injection of IPNV-challenge material. The remaining vaccinated fish were transported to the VESO Vikan marine field trial site and placed in two identical pens, each containing approximately 53 000 fish from the NC-6 group and 9000 fish from the NC-4 group. In the experimental bath challenge trial, the cumulative mortality was 75% and 78% in the control groups, and the relative percentage survival (RPS) of the NC-6-immunized fish vs. the reference vaccine groups was 60% and 82%, respectively. In the cohabitation challenge, the control mortality reached 74% and the IPNV-specific vaccine RPS was 72%. In both models, the reference vaccine lacking IPNV antigen gave a moderate but statistically significant non-specific protection. In the field, a natural outbreak of infectious pancreatic necrosis (IPN) occurred after 7 weeks lasting for approximately 3.5 months before problems due to winter ulcers became dominating. During this outbreak, mortality in the NC-4 groups were 33.5% and 31.6%, respectively, whereas mortality in the NC-6 groups were 6.9% and 5.3%, respectively, amounting to 81% IPNV-specific protection. In conclusion, the IPN protection estimates obtained by experimental challenges were consistent between tanks, and were confirmed by the field results.

The effect of experimental low zearalenone intoxication on ovarian follicles in pre-pubertal bitches.

PubMed

Gajecka, M

2013-01-01

Companion animals, including bitches, may be exposed to zearalenone (ZEN) toxins that are often present in feed, and ZEN intoxication may lead to ovarian dysfunction. This study involved evaluation of the degree of ZEN-induced hypo stimulation of ovary by determination of proliferative and apoptotic indices and description of the ultra-structural organization of ovarian follicles in pre-pubertal bitches subjected to experimental, long-term exposure to low-dose ZEN mycotoxicosis. The experiment involved 30 clinically healthy, immature Beagle bitches aged approximately 70 days with initial average body weight of 8 kg, randomly divided into three groups of 10 animals each: two experimental groups (EI and EII) and a control group (C). Over a period of 42 days, ZEN was administered per os to EI animals at a dose of 50 microg/kg BW, and to EII bitches at a dose of 75 microg/kg BW. Control group animals were fed placebo containing no ZEN for 42 days. Analytical samples of the mycotoxin were administered daily in gelatin capsules before morning feeding. All the bitches were subjected to ovario-hysterectomy at the end of the experiment. Proliferation index (PCNA method) and apoptotic index (TUNEL test) values were determined by immune-histological analyses. The median for apoptotic index was determined at 13.45 for group EI, 17.84 for group EII, and 8.59 for group C. The median for proliferation index was determined at 35.25 for group EII, 42.44 for group EI, and 70.60 for group C. The results of ultra-structural examinations of the ovaries revealed that experimental, ZEN-induced hyperestrogenism enhanced apoptosis and lowered the proliferative ability of follicular cells what contributed to organelle destruction in pre-pubertal bitches. The changes observed were particularly advanced in EII animals, which were administered a higher dose of ZEN.

Influence of the dark/light rhythm on the effects of UV radiation in the eyestalk of the crab Neohelice granulata.

PubMed

Vargas, Marcelo Alves; Geish, Marcio Alberto; Maciel, Fabio Everton; Cruz, Bruno Pinto; Filgueira, Daza de Moraes Vaz Batista; Ferreira, Gabrielle de Jesus; Nery, Luiz Eduardo Maia; Allodi, Silvana

2010-04-01

Crustaceans are interesting models to study the effects of ultraviolet (UV) radiation, and many species may be used as biomarkers for aquatic contamination of UV radiation reaching the surface of the Earth. Here, we investigated cell damage in the visual system of crabs Neohelice granulata that were acclimated to either 12L:12D, constant light, or constant dark, and were exposed to UVA or UVB at 12:00h (noon). The production of reactive oxygen species (ROS), antioxidant capacity against peroxyl radicals (ACAP), lipid peroxidation (LPO) damage, catalase activity, and pigment dispersion in the eye were evaluated. No significant differences from the three groups of controls (animals acclimated to 12L:12D, or in constant light, or not exposed to UV radiation) were observed in animals acclimated to 12L:12D, however, crabs acclimated to constant light and exposed to UV radiation for 30min showed a significant increase in ROS concentration, catalase activity, and LPO damage, but a decrease in ACAP compared with the controls. Crabs acclimated to constant darkness and exposed to UV for 30min showed a significantly increased ROS concentration and LPO damage, but the ACAP and catalase activity did not differ from the controls (animals kept in the dark while the experimental group was being exposed to UV radiation). Pigment dispersion in the pigment cells of eyes of animals acclimated to constant light was also observed. The results indicate that UVA and UVB alter specific oxidative parameters; however, the cell damage is more evident in animals deviated from the normal dark/light rhythm.

Improvement of learning domains of nursing students with the use of authentic assessment pedagogy in clinical practice.

PubMed

Chong, Edmund Jun Meng; Lim, Jessica Shih Wei; Liu, Yuchan; Lau, Yvonne Yen Lin; Wu, Vivien Xi

2016-09-01

With evolving healthcare demands, nursing educators need to constantly review their teaching methodologies in order to enhance learners' knowledge and competency of skills in the clinical settings. Learning is an active process in which meaning is accomplished on the basis of experience and that authentic assessment pedagogy will enable nursing students to play an active part in their learning. The study was conducted with an aim to examine nursing students' learning domains through the introduction of the authentic assessment pedagogy during their clinical practice. A quasi-experimental study (n = 54) was conducted over a period of 10 weeks at a local tertiary hospital. The experimental group was exposed to the authentic assessment pedagogy and were taught to use the assessment rubrics as an instrument to help enhance their learning. Students were assessed and scored according to the assessment rubrics, which were categorized into four domains; cognitive, psychomotor, affective and critical thinking abilities. The findings indicated that an overall score for the four domains between the experimental and control groups were significant, with p value of <0.05. Critical thinking scores were indicative of consistent improvement within the experimental group. The findings confirmed that learning outcomes of the nursing students were enhanced through the early introduction of the authentic assessment pedagogy in the clinical setting. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Experimental study on the possibility of brain damage induced by chronic treatment with phenobarbital, clonazepam, valproic acid and topiramate in immature rats].

PubMed

Zhu, Hai-xia; Cai, Fang-cheng; Zhang, Xiao-ping

2007-02-01

To explore the possibility of brain damage induced by several anti-epileptic drugs (AEDs) at therapeutic level to immature brain of rat. Totally 160 healthy Spraque-Dawley (SD) rats selected for the study were divided into infant and adult groups. Each age group was treated with phenobarbital (PB), clonazepam (CZP), valproic acid (VPA), topiramate (TPM) or normal saline respectively for 2 or 5 weeks with 8 rats in each group. The steady-state plasma concentrations of AEDs at the experimental dosage were coincided with the range of clinical therapeutic concentrations. Drug levels in plasma were determined by fluorescence polarization. Body and brain weights were measured when the rats were sacrificed. Histological studies on the tissues of frontal lobes and hippocampus were performed by Nissl staining. And ultrastructural changes of brain were observed by the transmission electron microscopy. Plasma neuron-specific enolase (NSE) was determined by ELISA. Expression of apoptosis-related proteins Bcl-2 and Bax in neurons was detected by immunohistochemistry. Neuronal apoptosis was detected by terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL). (1) There were no significant differences in brain weight among all adults groups. While remarkable reduction of brain weight was observed in immature rats exposed to CZP or PB (P < 0.01) for long term. (2) Significant neurodegeneration, neuronal necrosis and decrease in the number of neurons can be observed in the immature rats exposed to CZP or PB for long period. (3) For immature rats, concentration of plasma NSE was increased even after short-term treatment with PB [(8.84 +/- 2.10) nmol/L] compared with control group [(6.27 +/- 1.27) nmol/L] (P < 0.01). And it was increased in immature rats exposed to CZP [(8.15 +/- 1.67) nmol/L] or PB [(8.07 +/- 1.27) nmol/L] for long term compared with controls [(6.02 +/- 1.20) nmol/L] (P < 0.01). But there were no significant differences between AEDs-treated adult rats and control rats. (4) The expression of Bcl-2 and Bax protein in mature brain did not change at therapeutic level. In contrast, expression of Bax protein in the frontal lobe was increased significantly in immature rats receiving CZP and PB for long period compared with control. (5) The number of TUNEL positive cells in immature rats exposed to CZP or PB for long term was obviously increased. PB and CZP may result in remarkable histological abnormalities, neuronal apoptosis and necrosis in immature brain. The brain damage induced by PB was more serious and persistent than that induced by CZP.

Control of experimental Triatoma infestans populations: effect of pour-on cypermethrin applied to chickens under natural conditions in the Argentinean Chaco region.

PubMed

Amelotti, I; Catalá, S S; Gorla, D E

2014-06-01

Among peridomestic structures, chicken coops are sites of major importance for the domestic ecology of Triatoma infestans (Hemiptera: Reduviidae). The aim of this study was to evaluate in an experimental context the effects of a cypermethrin pour-on formulation applied to chickens on blood intake, moulting and mortality in T. infestans, under the natural climatic conditions of a region endemic for Chagas' disease. Experimental chicken huts were made of bricks and covered with plastic mosquito nets. Ninety fourth-instar nymphs were maintained in each hut. The study used a completely random design in which chickens in the experimental group were treated with a cypermethrin pour-on formulation. Five replicates (= huts) of the experimental and control groups were conducted. The number of live T. infestans, blood intake and moults to fifth-instar stage were recorded at 1, 5, 20, 35 and 45 days after the application of cypermethrin. Cumulative mortality was higher in nymphs exposed to treated chickens (> 71%) than in control nymphs (< 50%) (P < 0.01). Blood intake and moulting rate were lower in nymphs fed on treated chickens than in control nymphs (P < 0.05). Pour-on cypermethrin was able to cause significant mortality, although it did not eliminate the experimental population of T. infestans. © 2013 The Royal Entomological Society.

Perinatal Asphyxia May Influence the Level of Beta-Amyloid (1-42) in Cerebrospinal Fluid: An Experimental Study on Newborn Pigs.

PubMed

Benterud, Torkil; Pankratov, Leonid; Solberg, Rønnaug; Bolstad, Nils; Skinningsrud, Anders; Baumbusch, Lars; Sandvik, Leiv; Saugstad, Ola Didrik

2015-01-01

Total tau (T-tau), phosphorylated tau (p-Tau) and Beta-Amyloid 1-42 (AB42) in Cerebrospinal Fluid (CSF) are useful biomarkers in neurodegenerative diseases. The aim of the study was to investigate the role of these and other CSF biomarkers (T-tau, p-Tau, AB42, S100B and NSE), during hypoxia-reoxygenation in a newborn pig model. Thirty newborn pigs were included in a study of moderate or severe hypoxia. The moderate hypoxia group (n = 12) was exposed to global hypoxia (8% O2) until Base excess (BE) reached -15 mmol/l. The pigs in the group exposed to severe hypoxia (n = 12) received 8% O2 until BE reached -20 mmol/l or mean Blood Pressure fell below 20 mm Hg, The control group (n = 6) was kept at room air. For all treatments, the CSF was collected at 9.5 hours after the intervention. The level of AB42 in CSF was significantly lower in the pigs exposed to severe hypoxia compared with the control group, 922(SD +/-445)pg/ml versus. 1290(SD +/-143) pg/ml (p<0.05), respectively. Further, a non-significant reduction of AB42 was observed in the group exposed to moderate hypoxia T-tau and p-Tau revealed no significant differences between the intervention groups and the control group, however a significantly higher level of S100B was seen in the CSF of pigs receiving hypoxia in comparison to the level in the control group. Further on, there was a moderate negative correlation between the levels of AB42 and S100B in CSF, as well as a moderate negative correlation between Lactate in blood at end of hypoxia and AB42 in CSF. This is the first study to our knowledge that demonstrated a significant drop in AB42 in CSF after neonatal hypoxia. Whether or not this has an etiological basis for adult neurodegenerative disorders needs to be studied with additional experiments and epidemiological studies. AB42 and S100B are significantly changed in neonatal pigs subjected to hypoxia compared to controls and thus may be valuable biomarkers of perinatal asphyxia.

Perinatal Asphyxia May Influence the Level of Beta-Amyloid (1-42) in Cerebrospinal Fluid: An Experimental Study on Newborn Pigs

PubMed Central

Benterud, Torkil; Pankratov, Leonid; Solberg, Rønnaug; Bolstad, Nils; Skinningsrud, Anders; Baumbusch, Lars; Sandvik, Leiv; Saugstad, Ola Didrik

2015-01-01

Objective Total tau (T-tau), phosphorylated tau (p-Tau) and Beta-Amyloid 1–42 (AB42) in Cerebrospinal Fluid (CSF) are useful biomarkers in neurodegenerative diseases. The aim of the study was to investigate the role of these and other CSF biomarkers (T-tau, p-Tau, AB42, S100B and NSE), during hypoxia-reoxygenation in a newborn pig model. Design Thirty newborn pigs were included in a study of moderate or severe hypoxia. The moderate hypoxia group (n = 12) was exposed to global hypoxia (8% O2) until Base excess (BE) reached -15 mmol/l. The pigs in the group exposed to severe hypoxia (n = 12) received 8% O2 until BE reached -20 mmol/l or mean Blood Pressure fell below 20 mm Hg, The control group (n = 6) was kept at room air. For all treatments, the CSF was collected at 9.5 hours after the intervention. Results The level of AB42 in CSF was significantly lower in the pigs exposed to severe hypoxia compared with the control group, 922(SD +/-445)pg/ml versus. 1290(SD +/-143) pg/ml (p<0.05), respectively. Further, a non-significant reduction of AB42 was observed in the group exposed to moderate hypoxia T-tau and p-Tau revealed no significant differences between the intervention groups and the control group, however a significantly higher level of S100B was seen in the CSF of pigs receiving hypoxia in comparison to the level in the control group. Further on, there was a moderate negative correlation between the levels of AB42 and S100B in CSF, as well as a moderate negative correlation between Lactate in blood at end of hypoxia and AB42 in CSF. Interpretation This is the first study to our knowledge that demonstrated a significant drop in AB42 in CSF after neonatal hypoxia. Whether or not this has an etiological basis for adult neurodegenerative disorders needs to be studied with additional experiments and epidemiological studies. AB42 and S100B are significantly changed in neonatal pigs subjected to hypoxia compared to controls and thus may be valuable biomarkers of perinatal asphyxia. PMID:26501201

The effects of food advertising and cognitive load on food choices.

PubMed

Zimmerman, Frederick J; Shimoga, Sandhya V

2014-04-10

Advertising has been implicated in the declining quality of the American diet, but much of the research has been conducted with children rather than adults. This study tested the effects of televised food advertising on adult food choice. Participants (N = 351) were randomized into one of 4 experimental conditions: exposure to food advertising vs. exposure to non-food advertising, and within each of these groups, exposure to a task that was either cognitively demanding or not cognitively demanding. The number of unhealthy snacks chosen was subsequently measured, along with total calories of the snacks chosen. Those exposed to food advertising chose 28% more unhealthy snacks than those exposed to non-food-advertising (95% CI: 7% - 53%), with a total caloric value that was 65 kcal higher (95% CI: 10-121). The effect of advertising was not significant among those assigned to the low-cognitive-load group, but was large and significant among those assigned to the high-cognitive-load group: 43% more unhealthy snacks (95% CI: 11% - 85%) and 94 more total calories (95% CI: 19-169). Televised food advertising has strong effects on individual food choice, and these effects are magnified when individuals are cognitively occupied by other tasks.

Within-group male relatedness reduces harm to females in Drosophila

PubMed Central

Allen, Felicity; Wigby, Stuart; Pizzari, Tommaso

2018-01-01

Resolving the mechanisms that switch competition to cooperation is key to understand biological organization1. This is particularly relevant for intrasexual competition, which often leads to males harming females2. Recent theory proposes that kin selection may modulate female harm by relaxing competition among relatives3–5. We experimentally manipulated the relatedness of groups of male Drosophila melanogaster competing over females to demonstrate that, as expected, within group relatedness inhibits male competition and female harm. Females exposed to three brothers unrelated to the female had higher lifetime reproductive success and slower reproductive ageing compared to females exposed to triplets of males unrelated to each other. Triplets of brothers also fought less with each other, courted females less intensively and lived longer than triplets of unrelated males. However, associations among brothers may be vulnerable to invasion by minorities of unrelated males: when two brothers were matched with an unrelated male, the latter sired on average twice as many offspring as either brother. These results demonstrate that relatedness can profoundly affect fitness through its modulation of intrasexual competition, as flies plastically adjust sexual behaviour in a way consistent with kin selection theory. PMID:24463521

[The effects of infrasound on the blood coagulation function of guinea pigs].

PubMed

Ma, Wen-min; Qi, Peng; Zhang, Jian-zhong; Yi, Yong; Chen, Xing-ming; Zhang, Jun; Han, Rui-gang

2011-03-01

To study the change of the blood coagulation function of guinea pigs exposed to 16 Hz/120 dB, 16 Hz/125 dB infrasound and to explore the mechanism of circulation system damage. Seventy-two guinea pigs were divided into 3 groups: the control group, the group exposed to 16 Hz/120 dB infrasound for 1.5 h a day and the group exposed to 16 Hz/125 dB infrasound for 1.5 h a day. Each exposure group was divided into 4 sub-groups (8 guinea pigs a sub-group) which were exposed to infrasound for 1, 7, 14 and 21 d, respectively. The coagulation function and serum nitric oxide (NO) were measured for control group and all sub-groups after exposure to infrasound. The prothrombin time (PT), international normalized ratio (INR) and serum NO of group exposed to 16 Hz/125 dB infrasound were (31.16 ± 3.05) s, 2.53 ± 1.21 and (88.304 ± 52.601) µmol/L, respectively, which were significantly higher than those [(21.36 ± 0.10) s, 1.65 ± 0.07 and (30.943 ± 26.864) µmol/L] of control group (P < 0.05). PT and INR of sub-groups exposed to 16 Hz/125 dB infrasound for 14 and 21 d were significantly higher than those of control group. NO of sub-groups exposed to 16 Hz/125 dB infrasound for 1 week and 2 weeks were significantly higher than that of control group (P < 0.05), but NO of sub-group exposed to 16 Hz/125 dB infrasound for 3 weeks decreased slightly. The blood coagulation function of guinea pigs exposed to 16 Hz/125 dB infrasound decreased, PT and INR may be used as the indexes to assess of blood coagulation function change induced by the infrasound exposure.

Inhalation of diesel engine exhaust affects spermatogenesis in growing male rats.

PubMed

Watanabe, N; Oonuki, Y

1999-07-01

We conducted experiments to determine whether diesel engine exhaust affects reproductive endocrine function in growing rats. The rats were assigned to three groups: a group exposed to total diesel engine exhaust containing 5.63 mg/m3 particulate matter, 4.10 ppm nitrogen dioxide, and 8.10 ppm nitrogen oxide; a group exposed to filtered exhaust without particulate matter; and a group exposed to clean air. Dosing experiments were performed for 3 months beginning at birth (6 hr/day for 5 days/week). Serum levels of testosterone and estradiol were significantly higher in animals exposed to total diesel exhaust and filtered exhaust (p < 0.05 for each group) as compared to the controls. Follicle-stimulating hormone was significantly decreased in the two groups exposed to diesel exhaust as compared to the control group (p < 0.05). Luteinizing hormone was significantly decreased in the total exhaust-exposed group as compared to the control and filtered groups (p < 0.05). Although testis weight did not show any significant difference among the groups, sperm production and activity of testicular hyaluronidase were significantly reduced in both exhaust-exposed groups as compared to the control group. Histological examination showed decreased numbers of step 18 and 19 spermatids in stage VI, VII, and VIII tubules in the testes of both diesel exhaust-exposed groups. This study suggests that diesel exhaust stimulates hormonal secretion of the adrenal cortex, depresses gonadotropin-releasing-hormone, and inhibits spermatogenesis in rats. Because these effects were not inhibited by filtration, the gaseous phase of the exhaust appears to be more responsible than particulate matter for disrupting the endocrine system.

Experimental transmission of Powassan virus (Flaviviridae) by Ixodes scapularis ticks (Acari:Ixodidae).

PubMed

Costero, A; Grayson, M A

1996-11-01

Transmission experiments were performed with Ixodes scapularis ticks from an uninfected laboratory colony. Immature and adult ticks were exposed to Powassan (POW) viremic hamsters and rabbits, respectively. Oral infection rates for engorged larvae, nymphs and females fed on POW-infected hosts were 10%, 40%, and 57%, respectively. Transstadial transmission rates for nymphs exposed to POW virus as larvae, adults exposed as larvae, and adults exposed as nymphs, were 9.5%, 10%, and 54%, respectively. Evidence of transovarial transmission occurred when two uninfected hamsters, exposed to F2 larvae and nymphs originally exposed to POW virus in the F1 nymphal stage, seroconverted to POW virus with hemagglutination inhibition titers of 80 and 5,120, respectively; the transovarial transmission rate was 16.6%. All developmental stages were able to transmit virus orally to uninfected hosts regardless of when the ticks were originally exposed to the virus. These results suggest that I. scapularis is a competent vector of POW virus under experimental conditions.

Effects of Boric Acid on Fracture Healing: An Experimental Study.

PubMed

Gölge, Umut Hatay; Kaymaz, Burak; Arpaci, Rabia; Kömürcü, Erkam; Göksel, Ferdi; Güven, Mustafa; Güzel, Yunus; Cevizci, Sibel

2015-10-01

Boric acid (BA) has positive effects on bone tissue. In this study, the effects of BA on fracture healing were evaluated in an animal model. Standard closed femoral shaft fractures were created in 40 male Sprague-Dawley rats under general anesthesia. The rats were allocated into five groups (n = 8 each): group 1, control with no BA; groups 2 and 3, oral BA at doses of 4 and 8 mg/kg/day, respectively; group 4, local BA (8 mg/kg); and group 5, both oral and local BA (8 mg/kg/day orally and 8 mg/kg locally). After closed fracture creation, the fracture line was opened with a mini-incision, and BA was locally administered to the fracture area in groups 4 and 5. In groups 2, 3, and 5, BA was administered by gastric gavage daily until sacrifice. The rats were evaluated by clinical, radiological, and histological examinations. The control group (group 1) significantly differed from the local BA-exposed groups (groups 4 and 5) in the clinical evaluation. Front-rear and lateral radiographs revealed significant differences between the local BA-exposed groups and the control and other groups (p < 0.05). Clinical and radiological evaluations demonstrated adequate agreement between observers. The average histological scores significantly differed across groups (p = 0.007) and were significantly higher in groups 4 and 5 which were the local BA (8 mg/kg) and both oral and local BA (8 mg/kg/day orally and 8 mg/kg locally), respectively, compared to the controls. This study suggests that BA may be useful in fracture healing. Further research is required to demonstrate the most effective local dosage and possible use of BA-coated implants.

Early ovarian follicular development in prepubertal Wistar rats acutely exposed to androgens.

PubMed

Paixão, L; Velez, L M; Santos, B R; Tusset, C; Lecke, S B; Motta, A B; Spritzer, P M

2016-08-01

Androgens may directly modulate early ovarian follicular development in preantral stages and androgen excess before puberty may disrupt this physiological process. Therefore, the aim of this study was to investigate the dynamics of follicular morphology and circulating androgen and estradiol levels in prepubertal Wistar rats acutely exposed to androgens. Prepubertal female Wistar rats were distributed into three groups: control, equine chorionic gonadotropin (eCG) intervention and eCG plus dehydroepiandrosterone (DHEA) intervention (eCG+DHEA). Serum DHEA, testosterone and estradiol levels were determined, and ovarian morphology and morphometry were assessed. The eCG+DHEA group presented increased serum estradiol and testosterone levels as compared with the control group (P<0.01), and higher serum DHEA concentration v. the eCG-only and control groups (P<0.01). In addition, the eCG+DHEA group had a higher number of, and larger-sized, primary and secondary follicles as compared with the control group (P<0.05). The eCG group presented intermediate values for number and size of primary and secondary follicles, without significant differences as compared with the other two groups. The number of antral follicles was higher in the eCG+DHEA and eCG groups v. controls (P<0.05). The number of primordial, atretic and cystic follicles were similar in all groups. In conclusion, the present experimental model using an acute eCG+DHEA intervention was useful to investigate events involved in initial follicular development under hyperandrogenic conditions, and could provide a reliable tool to study defective follicular development with possible deleterious reproductive consequences later in life.

A Quasi-Experimental Study of Two Selected Units of the Industrial Arts Curriculum Project Materials to Determine the Measurable Additive Effects of a Unit on Design in Manfacturing Technology upon a Similar Unit on Design in Construction Technology.

ERIC Educational Resources Information Center

Kuwik, Paul David

The purpose of the study was to determine whether exposing junior high school students to a unit on design in construction technology and to a unit on design in manufacturing technology significantly affects their achievement on a test measuring "Technological Principles of Design" when compared to a group of junior high school students exposed…

Impact of an educational intervention for district nurses about preparedness to encounter women exposed to intimate partner violence.

PubMed

Sundborg, Eva; Törnkvist, Lena; Wändell, Per; Saleh-Stattin, Nouha

2017-09-18

To evaluate the impact of an educational intervention on the preparedness of district nurses at primary healthcare centres to encounter women exposed to intimate partner violence. An observational quasi-experimental study. Participants were divided into an intervention group (n = 117) and a control group (n = 204), both from the eastern part of Sweden. A group of nurses from across Sweden (the 'national group,' n = 217) was also recruited. The Violence Against Women Health Care Provider Survey was used pre- and 1 year postintervention to measure the intervention's impact. This survey, which measured preparedness, included eight factors: practitioner preparedness, self-confidence, lack of control, comfort following disclosure, professional support, practice pressures, abuse inquiry and consequences of asking. anova, the paired Wilcoxon test, the Mann-Whitney U test and the Kruskal-Wallis test were used to analyse the data. Pre-intervention preparedness was equal in all three groups. In the intervention group, preparedness related to the factor practitioner lack of control increased (p = 0.003), but a comparison of change between the intervention and control groups showed no significant intervention effect (p = 0.069). The results indicate that the intervention had a low impact on district nurses' preparedness. The educational intervention must be adjusted; a main focus of changes should be the addition of continuing postintervention supervision and support. © 2017 Nordic College of Caring Science.

Effects of whole-body vibration on muscle architecture, muscle strength, and balance in stroke patients: a randomized controlled trial.

PubMed

Marín, Pedro J; Ferrero, Cristina M; Menéndez, Héctor; Martín, Juan; Herrero, Azael J

2013-10-01

The aim of the present study was to analyze the effects of whole-body vibration on lower limb muscle architecture, muscle strength, and balance in stroke patients during a period of 3 mos. The inclusion criteria were having had ischemic or hemorrhagic stroke at least 6 mos before the study and a National Institutes of Health Stroke Scale score of greater than 1 and less than 20. The patients were randomly divided into two groups: an experimental group (n = 11, six men and five women; age, 62.4 ± 10.7 yrs; height, 1.64 ± 0.07 m; mass, 69.4 ± 12.9 kg) and a sham group (n = 9, five men and four women; age, 64.4 ± 7.6 yrs; height, 1.62 ± 0.07 m; mass, 75.0 ± 15.8 kg). The experimental group received a whole-body vibration treatment, with an increase in frequency, sets, and time per set during 17 sessions. The sham group performed the same exercises as that of the experimental group but was not exposed to vibration. Outcome variables included the muscle architecture (the rectus femoris, the vastus lateralis, and the medial gastrocnemius), the maximal isometric voluntary contraction of the knee extensors, and the Berg Balance Scale. There were no significant differences between the groups on the primary outcomes of lower limb muscle architecture, muscle strength, and balance. It seems that whole-body vibration exercise does not augment the increase in neuromuscular performance and lower limb muscle architecture induced by isometric exercise alone in stroke patients.

Technetium-99m diethylenetriaminepentaacetic acid radioaerosol scintigraphy in organophosphate induced pulmonary toxicity: experimental study.

PubMed

Yavuz, Yucel; Kaya, Eser; Yurumez, Yusuf; Sahin, Onder; Bas, Orhan; Fidan, Huseyin; Sezer, Murat

2008-09-01

The aim of this experimental study was to investigate pathological signs of lung damages caused by acute organophosphate (OP) poisoning by using Tc-99m DTPA radioaerosol scintigraphy and histopathological investigation. Fourteen rabbits were divided into two equal groups (n = 7). Group 1 (control group) received normal saline (same volume of fenthion, 2 ml/kg) via orogastric tube. Group 2 (OP toxicity group) received 150 mg/kg of fenthion (diluted fenthion, 2 ml/kg) via orogastric tube. Six hours later, Tc-99m-DTPA aerosol inhalation lung scintigraphy was performed in both groups. Then all rabbits were anesthetized with ketamine hydrochloride (35 mg/kg, i.p.) and xysilazine (5 mg/kg, i.p.), and sacrificed by intracardiac blood discharge. The lungs were then removed. There was a significant difference in T1/2 values of Tc-99m DTPA clearance between control group and OP toxicity group (p = 0.04). Intraparenchymal vascular congestion and thrombosis, intraparenchymal hemorrhage, respiratory epithelial proliferation, number of macrophages in the alveolar, and bronchial lumen, alveolar destruction, emphysematous changes, and bronchoalveolar hemorrhage scores were significantly higher in the rabbits exposed to OP compared with the control group (p < 0.05). This study showed that OP toxicity caused a decrease in the alveolar clearance. Tc-99m DTPA radioaerosol inhalation lung scintigraphy was found to be a sensitive determination of acute lung damage in OP poisoning.

Quantitative analysis of macrophages in wound healing of rat skin subjected to loud noise stress.

PubMed

Rafi, Aisha; Khan, Muhammad Yunus; Minhas, Liaqat Ali

2014-01-01

Factors affecting skin wound healing have always been a central consideration in medical practice. Loud noise is biological stressor affecting the body systems at various levels. The present study was taken to study the effect of loud noise stress on the macrophages during wound healing process in male rat skin. One hundred and eighty male Sprague Dawley rats were randomly divided into control group-A and experimental group-B. Each group comprised 90 animals. Control and experimental groups were further subdivided into three subgroups of 30 animals each, corresponding to the day of sacrifice of animals, i.e., day 3, 5 and 7 after surgery. After induction of local anaesthesia a linear full thickness incision paravertebral to thoracic spine was made on the dorsum of rat. The experimental group B was exposed to loud noise stimulus (recorded noise of aero planes and gun fire) set at 97dBA to 102 dBA with a sound level meter. The animals were decapitated on day 3, 5 and 7 after surgery. Tissue was processed for paraffin embedding and stained by Hematoxylin and Eosin and Mallory's trichrome stain. Data was collected for the incisional space of the wound. Quantitative data of number of macrophages was analysed by Student's' test for the detection of any significant differences between the mean number in the experimental and control groups. All the quantitative data was expressed as means ± SE. A p-value of ≤ 0.05 was considered statistically significant. In this study macrophages were decreased statistically significantly at day 3 after surgery and thereafter increased significantly on day 5 and 7 after surgery in the experimental subgroups as compared to their match control subgroups. These results show that loud noise stress affects the cells (macrophages) involved in the healing of the wound therefore it is expected to have impact on the stages of wound healing.

Significant accumulation of persistent organic pollutants and dysregulation in multiple DNA damage repair pathways in the electronic-waste-exposed populations

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Xiaobo; Jing, Yaqing; Wang, Jianhai

Electronic waste (e-waste) has created a worldwide environmental and health problem, by generating a diverse group of hazardous compounds such as persistent organic pollutants (POPs). Our previous studies demonstrated that populations from e-waste exposed region have a significantly higher level of chromosomal aberrancy and incidence of DNA damage. In this study, we further demonstrated that various POPs persisted at a significantly higher concentration in the exposed group than those in the unexposed group. The level of reactive oxygen species and micronucleus rate were also significantly elevated in the exposed group. RNA sequencing analysis revealed 31 genes in DNA damage responsesmore » and repair pathways that were differentially expressed between the two groups (Log 2 ratio >1 or <−1). Our data demonstrated that both females and males of the exposed group have activated a series of DNA damage response genes; however many important DNA repair pathways have been dysregulated. Expressions of NEIL1/3 and RPA3, which are critical in initiating base pair and nucleotide excision repairs respectively, have been downregulated in both females and males of the exposed group. In contrast, expression of RNF8, an E3 ligase involved in an error prone non-homologous end joining repair for DNA double strand break, was upregulated in both genders of the exposed group. The other genes appeared to be differentially expressed only when the males or females of the two groups were compared respectively. Importantly, the expression of cell cycle regulatory gene CDC25A that has been implicated in multiple kinds of malignant transformation was significantly upregulated among the exposed males while downregulated among the exposed females. In conclusion, our studies have demonstrated significant correlations between e-waste disposing and POPs accumulation, DNA lesions and dysregulation of multiple DNA damage repair mechanisms in the residents of the e-waste exposed region. - Highlights: • We compared concentration of POPs, ROS and micronucleus rate in POPs exposed area. • Significant accumulation of POPs homologous in the e-waste exposed residents. • DNA damage and DNA damage repair pathways have been differentially activated. • Females and males in the exposed group have different responses to the DNA damage. • Exposed males may be more prone to undergo malignant transformation.« less

Development of an animal model of fibrous cholangitis in pigs.

PubMed

Lainakis, Nektarios G; Papalois, Apostolos; Agrogiannis, Georgios; Antonopoulos, Constantine N; Michail, Panagiotis; Bastounis, Elias; Patsouris, Efstathios; Felekouras, Evangelos

2014-04-01

The aim of this study was to develop a model of fibrous cholangitis in the offspring of gravid domestic pigs through the administration of 1,4-phenylene diisothiocyanate (DITC). Six young domestic pigs and two gravid pigs with their offspring (21 pigs) were used as experimental models and six wild-type animals were used as controls. All pigs were divided into five main groups and five subgroups, according to their developmental stage and time of exposure to DITC. The following histopathological characteristics were quantitatively evaluated on a scale of 0-5: ductal proliferation, periportal fibrosis, inflammatory infiltration, periductal fibrosis and edema, intraluminal fibrosis, duct wall thickening, epithelial apoptosis, and arterial hyperplasia/hypertrophy. Statistically significant differences were observed for most of the histopathological markers between the group of pigs' offspring that received DITC at early gestation and their control group. Moreover, the group of animals that were exposed to the agent at early gestation exhibited significant differences for all histopathological characteristics compared to the animals that were exposed at late gestation. On the other hand, no statistically significant differences were observed between the group of animals that received the agent at late gestation and their healthy controls. Administration of DITC to domestic pigs in early pregnancy may induce histopathological patterns of fibrous cholangitis to their offspring imitating biliary atresia. This model may provide insight to the pathogenesis of the obstructive cholangitis in pigs.

NREM2 and Sleep Spindles Are Instrumental to the Consolidation of Motor Sequence Memories

PubMed Central

Laventure, Samuel; Fogel, Stuart; Lungu, Ovidiu; Albouy, Geneviève; Sévigny-Dupont, Pénélope; Vien, Catherine; Sayour, Chadi; Carrier, Julie; Benali, Habib; Doyon, Julien

2016-01-01

Although numerous studies have convincingly demonstrated that sleep plays a critical role in motor sequence learning (MSL) consolidation, the specific contribution of the different sleep stages in this type of memory consolidation is still contentious. To probe the role of stage 2 non-REM sleep (NREM2) in this process, we used a conditioning protocol in three different groups of participants who either received an odor during initial training on a motor sequence learning task and were re-exposed to this odor during different sleep stages of the post-training night (i.e., NREM2 sleep [Cond-NREM2], REM sleep [Cond-REM], or were not conditioned during learning but exposed to the odor during NREM2 [NoCond]). Results show that the Cond-NREM2 group had significantly higher gains in performance at retest than both the Cond-REM and NoCond groups. Also, only the Cond-NREM2 group yielded significant changes in sleep spindle characteristics during cueing. Finally, we found that a change in frequency of sleep spindles during cued-memory reactivation mediated the relationship between the experimental groups and gains in performance the next day. These findings strongly suggest that cued-memory reactivation during NREM2 sleep triggers an increase in sleep spindle activity that is then related to the consolidation of motor sequence memories. PMID:27032084

Decontamination training: with and without virtual reality simulation.

PubMed

Farra, Sharon Lee; Smith, Sherrill; Gillespie, Gordon Lee; Nicely, Stephanie; Ulrich, Deborah L; Hodgson, Eric; French, DeAnne

2015-01-01

Nurses must be prepared to care for patients following a disaster, including patients exposed to hazardous contaminants. The purpose of this study was to examine the use of virtual reality simulation (VRS) to teach the disaster-specific skill of decontamination. A quasi-experimental design was used to assign nursing students from 2 baccalaureate nursing programs to 1 of 2 groups to learn the disaster skill of decontamination-printed written directions or VRS. Performance, knowledge, and self-efficacy were outcome measures. Although students in the treatment group had significantly lower performance scores than the control group (p = 0.004), students taking part in VRS completed the skill in a significantly shorter amount of time (p = 0.008). No significant group differences were found for self-efficacy (p = 0.172) or knowledge (p = 0.631). However, students in the VRS treatment group reported high levels of satisfaction with VRS as a training method. The disaster-specific skill of decontamination is a low-volume, high-risk skill that must be performed with accuracy to protect both exposed patients and providers performing decontamination. As frontline providers for casualties following a disaster event, emergency nurses must be prepared to perform this skill when needed. Preparation requires cost-effective, timely, and evidence-based educational opportunities that promote positive outcomes. Further investigation is needed to determine the benefits and long-term effects of VRS for disaster education.

DNA damage, p53, Ki-67 and COX-2 expression in rat tongue cells exposed to nandrolone decanoate.

PubMed

Pozzi, Renan; Fernandes, Kelly Rosseti; Foot Gomes de Moura, Carolina; Ferrari, Raquel Agnelli Mesquita; Fernandes, Kristianne Porta Santos; Chaves, Marcelo Donizeti; Renno, Ana Claudia Muniz; Ribeiro, Daniel Araki

2013-05-01

The objective of this article was to evaluate the impact potential of nandrolone decanoate on DNA damage, cellular regulatory proteins and cyclooxygenase (COX)-2 in oral mucosa cells of Wistar rats. A total of 40 rats were distributed into four groups. Two experimental groups were treated with nandrolone decanoate, at 5 mg/kg doses, subcutaneously, three times a week in two periods: 15 and 30 days. The remaining groups received only 0.9% saline subcutaneously, three times a week. To evaluate genetic damage, nandrolone decanoate at 15 mg/kg dose was exposed to 24 h. In the histopathological analysis, no remarkable morphological changes were observed in tongue tissue in all groups. Significant increase in immunoexpression of Ki-67, p53, COX-2 proteins was detected in the groups treated with nandrolone decanoate during 15 and 30 days, when compared to their respective controls. A positive correlation between immunoexpression of p53 and COX-2 protein was detected following nandrolone decanoate exposure. DNA damage was induced by nandrolone decanoate in oral mucosa cells at 15 mg/kg dose. Our results suggest that nandrolone decanoate was able to alter the expression of cell cycle-related proteins, as well as to induce genetic damage and COX-2 immunoexpression in tongue cells of Wistar rats.

Protective Effects of Vitamin E Consumption against 3MT Electromagnetic Field Effects on Oxidative Parameters in Substantia Nigra in Rats.

PubMed

Ghanbari, Ahmad Ali; Shabani, Kobra; Mohammad Nejad, Daryoush

2016-10-01

Electromagnetic fields (EMFs) can influence the biological system by the formation of free radicals in cells. The EMFs are able to deteriorate defense system against free radicals that leads to oxidative stress (OS). Lipid peroxidation process (LPO) is an index of oxidative stress, and the Malandialdehyde (MDA) is the final product of LPO. Vitamin E is the most important antioxidant which inhibits the LPO process. The aim of this study was to evaluate the effects of 3MT EMF exposure on oxidative stress parameters in substantia nigra and the role of vitamin E in reducing oxidative stress and preventing of LPO process. 40 male Wistar rats were randomly divided into 4 groups: 1) Control group: received standard food without exposure to EMF and without consumption of vitamin E, 2) Experimental group 1: was exposed to EMF (3MT) 4 h/day for 50 days, 3) The experimental group 2: received 200 mg/kg vitamin E with gavage every day and also was exposed to EMF (3MT) 4 h/day for 50 days, 4) Sham group: received water with gavage for 50 days. A significant increase in MDA levels and Glutation peroxidase (GSH-Px) activity of the substantia nigra following 50 days exposure to EMF was detected, but the superoxide dismutase (SOD) activity was decreased. Exposure did not change total antioxidant capacity (TAC) levels in plasma. Vitamin E treatment significantly prevented the increase of the MDA levels and GSHPx activity and also prevented the decrease of SOD activity in tissue but did not alter TAC levels. The GSH-Px activity increased because the duration and intensity of exposure were not enough to decrease it. We demonstrated two important findings; that 50 days exposure to 3 MT electromagnetic field caused oxidative stress by increasing the levels of MDA, and decreasing SOD activity in the substantia nigra; and that treatment with the vitamin E significantly prevented the oxidative stress and lipid peroxidation.

Xylitol-supplemented nutrition enhances bacterial killing and prolongs survival of rats in experimental pneumococcal sepsis

PubMed Central

Renko, Marjo; Valkonen, Päivi; Tapiainen, Terhi; Kontiokari, Tero; Mattila, Pauli; Knuuttila, Matti; Svanberg, Martti; Leinonen, Maija; Karttunen, Riitta; Uhari, Matti

2008-01-01

Background Xylitol has antiadhesive effects on Streptococcus pneumoniae and inhibits its growth, and has also been found to be effective in preventing acute otitis media and has been used in intensive care as a valuable source of energy. Results We evaluated the oxidative burst of neutrophils in rats fed with and without xylitol. The mean increase in the percentage of activated neutrophils from the baseline was higher in the xylitol-exposed group than in the control group (58.1% vs 51.4%, P = 0.03 for the difference) and the mean induced increase in the median strength of the burst per neutrophil was similarly higher in the xylitol group (159.6 vs 140.3, P = 0.04). In two pneumococcal sepsis experiments rats were fed either a basal powder diet (control group) or the same diet supplemented with 10% or 20% xylitol and infected with an intraperitoneal inoculation of S. pneumoniae after two weeks. The mean survival time was 48 hours in the xylitol groups and 34 hours in the control groups (P < 0.001 in log rank test). Conclusion Xylitol has beneficial effects on both the oxidative killing of bacteria in neutrophilic leucocytes and on the survival of rats with experimental pneumococcal sepsis. PMID:18334022

Cariogenic Potential of Inhaled Antiasthmatic Drugs.

PubMed

Brigic, Amela; Kobaslija, Sedin; Zukanovic, Amila

2015-08-01

The organism of children with asthma is exposed to the effects of the disease but also the drugs for its treatment. Antiasthmatic drugs have different modes that promote the caries formation which varies according to their basic pharmacological composition. Namely, these drugs have a relatively low pH (5.5), can contain sweeteners such as lactose monohydrate in order to improve the drug taste or both. Frequent consumption of these inhalers in combination with reduced secretion of saliva increases the risk of caries. The study sample consisted of 200 patients, age from 7-14 years, divided into two groups: control group (n1 = 100) consisted of healthy children and the experimental group consisted of children suffering from asthma (n2 = 100). In both groups of respondents are determined the DMFT index, plaque index value and hygienic-dietary habits using the questionnaire. The subjects in the control group had significantly higher DMFT index than subjects in the experimental group (p = 0.004). It is determined that there are no significant differences in the values of plaque index (p>0.05). The effect of different diseases or medications from their treatment, diet and fermentable carbohydrates in the etiology of dental caries cannot be observed outside the living conditions of subjects, their social epidemiologic status, age, habits, oral hygiene, fluoride use, etc.

Dosage response mortality of Japanese beetle, masked chafer, and June beetle (Coleoptera: Scarabaeidae) adults when exposed to experimental and commercially available granules containing Metarhizium brunneum

USDA-ARS?s Scientific Manuscript database

Adult beetles of three different white grub species, Japanese beetle, Popillia japonica, June beetle, Phyllophaga spp., and masked chafer, Cyclocephala spp. were exposed to experimental and commercially available granules containing Metarhizium brunneum (Petch) strain F52, to determine susceptibilit...

Effect of saliva decontamination procedures on shear bond strength of a one-step adhesive system.

PubMed

Ülker, E; Bilgin, S; Kahvecioğlu, F; Erkan, A I

2017-09-01

To evaluate the effect of different saliva decontamination procedures on the shear bond strength of a one-step universal adhesive system (Single Bond™ Universal Adhesive, 3M ESPE, St. Paul, MN, USA). The occlusal surfaces of 75 human third molars were ground to expose dentin. The teeth were divided into the following groups: Group 1 (control group): Single Bond™ Universal Adhesive was applied to the prepared tooth according to the manufacturer's recommendations and light cured; no contamination procedure was performed. Group 2: Bonding, light curing, saliva contamination, and dry. Group 3: Bonding, light curing, saliva contamination, rinse, and dry. Group 4: After the procedure performed in Group 2, reapplication of bonding. Group 5: After the procedure performed in Group 3, reapplication of bonding. Then, composite resins were applied with cylindrical-shaped plastic matrixes and light cured. For shear bond testing, a notch-shaped force transducer apparatus was applied to each specimen at the interface between the tooth and composite until failure occurred. The data were statistically analyzed using one-way ANOVA. One-way ANOVA revealed significant differences in shear bond strength between the control group and experimental Groups 2 and 4 (P < 0.05). No significant difference was found for experimental Groups 3 and 5 when compared to the control group (P > 0.05). The present in vitro study showed that water rinsing is necessary if cured adhesive resin is contaminated with saliva to ensure adequate bond strength.

Combined exposure to cyanobacterial biomass, lead and the Newcastle virus enhances avian toxicity.

PubMed

Pikula, Jiri; Bandouchova, Hana; Hilscherova, Klara; Paskova, Veronika; Sedlackova, Jana; Adamovsky, Ondrej; Knotkova, Zora; Lany, Petr; Machat, Jiri; Marsalek, Blahoslav; Novotny, Ladislav; Pohanka, Miroslav; Vitula, Frantisek

2010-10-01

Under environmental conditions, wild birds can be exposed to multiple stressors including natural toxins, anthropogenic pollutants and infectious agents at the same time. This experimental study was successful in testing the hypothesis that adverse effects of cyanotoxins, heavy metals and a non-pathogenic immunological challenge combine to enhance avian toxicity. Mortality occurred in combined exposures to naturally occurring cyanobacterial biomass and lead shots, lead shots and Newcastle vaccination as well as in single lead shot exposure. Mostly acute effects around day 10 were observed. On day 30 of exposure, there were no differences in the liver accumulation of lead in single and combined exposure groups. Interestingly, liver microcystin levels were elevated in birds co-exposed to cyanobacterial biomass together with lead or lead and the Newcastle virus. Significant differences in body weights between all Pb-exposed and Pb-non-exposed birds were found on days 10 and 20. Single exposure to cyanobacterial biomass resulted in hepatic vacuolar dystrophy, whereas co-exposure with lead led to more severe granular dystrophy. Haematological changes were associated with lead exposure, in particular. Biochemical analysis revealed a decrease in glucose and an increase in lactate dehydrogenase in single and combined cyanobacterial and lead exposures, which also showed a decreased antibody response to vaccination. The combined exposure of experimental birds to sub-lethal doses of individual stressors is ecologically realistic. It brings together new pieces of knowledge on avian health. In light of this study, investigators of wild bird die-offs should be circumspect when evaluating findings of low concentrations of contaminants that would not result in mortality on a separate basis. As such it has implications for wildlife biologists, veterinarians and conservationists of avian biodiversity. Copyright 2010 Elsevier B.V. All rights reserved.

Nonexpanded Adipose Stromal Vascular Fraction Local Therapy on Peripheral Nerve Regeneration Using Allografts.

PubMed

Mohammadi, Rahim; Mehrtash, Moein; Mehrtash, Moeid; Sajjadi, Seyedeh-Sepideh

2016-06-01

Adipose tissue possesses a population of multi-potent stem cells which can be differentiated to a Schwann cell phenotype and may be of benefit for treatment of peripheral nerve injuries. Effects of local therapy of nonexpanded adipose stromal vascular fraction (SVF) on peripheral nerve regeneration was studied using allografts in a rat sciatic nerve model. Thirty male white Wistar rats were divided into three experimental groups (n = 10), randomly: Sham-operated group (SHAM), allograft group (ALLO), SVF-treated group (ALLO/SVF). In SHAM group left sciatic nerve was exposed through a gluteal muscle incision and after homeostasis muscle was sutured. In the ALLO group the left sciatic nerve was exposed through a gluteal muscle incision and transected proximal to the tibio-peroneal bifurcation where a 10 mm segment was excised. The same procedure was performed in the ALLO/SVF group. The harvested nerves of the rats of ALLO group were served as allograft for ALLO/SVF group and vice versa. The SHAM and ALLO groups received 100 μL phosphate buffered saline and the ALLO/SVF group received 100 μL SVF (2.25 ± 0.45 × 10(7) cells) locally where the grafting was performed. Behavioral, functional, biomechanical, and gastrocnemius muscle mass showed earlier regeneration of axons in ALLO/SVF than in ALLO group (p < .05). Histomorphometic and immunohistochemical studies also showed earlier regeneration of axons in ALLO/SVF than in ALLO group (p < .05). Administration of nonexpanded SVF could accelerate functional recovery after nerve allografting in sciatic nerve. It may have clinical implications for the surgical management of patients after nerve transection.

Evaluating effectiveness of dynamic soundfield system in the classroom

PubMed Central

da Cruz, Aline Duarte; Alves Silvério, Kelly Cristina; Da Costa, Aline Roberta Aceituno; Moret, Adriane Lima Mortari; Lauris, José Roberto Pereira; de Souza Jacob, Regina Tangerino

2016-01-01

Research has reported on the use of soundfield amplification devices in the classroom. However, no study has used standardized tests to determine the potential advantages of the dynamic soundfield system for normally hearing students and for the teacher's voice. Our aim was to evaluate the impact of using dynamic soundfield system on the noise of the classroom, teacher's voice and students’ academic performance. This was a prospective cohort study in which 20 student participants enrolled in the third year of basic education were divided into two groups (i.e., control and experimental); their teacher participated. The experimental group was exposed to the dynamic soundfield system for 3 consecutive months. The groups were assessed using standardized tests to evaluate their academic performance. Further, questionnaires and statements were collected on the participants’ experience of using the soundfield system. We statistically analyzed the results to compare the academic performance of the control group with that of the experimental group. In all cases, a significance level of P < .05 was adopted. Use of the dynamic soundfield system was effective for improving the students’ academic performance on standardized tests for reading, improving the teacher's speech intelligibility, and reducing the teacher's vocal strain. The dynamic soundfield system minimizes the impact of noise in the classroom as demonstrated by the mensuration of the signal-to-noise ratio (SNR) and pupil performance on standardized tests for reading and student and teacher ratings of amplification system effectiveness. PMID:26780961

Brain Responses to a 6-Hz Binaural Beat: Effects on General Theta Rhythm and Frontal Midline Theta Activity

PubMed Central

Jirakittayakorn, Nantawachara; Wongsawat, Yodchanan

2017-01-01

A binaural beat is a beat phenomenon that is generated by the dichotic presentation of two almost equivalent pure tones but with slightly different frequencies. The brain responses to binaural beats remain controversial; therefore, the aim of this study was to investigate theta activity responses to a binaural beat by controlling factors affecting localization, including beat frequency, carrier tone frequency, exposure duration, and recording procedure. Exposure to a 6-Hz binaural beat on a 250 Hz carrier tone for 30 min was utilized in this study. Quantitative electroencephalography (QEEG) was utilized as the recording modality. Twenty-eight participants were divided into experimental and control groups. Emotional states were evaluated by Brunel Mood Scale (BRMUS) before and after exposing to the stimulus. The results showed that theta activity was induced in the entire cortex within 10 min of exposure to the stimulus in the experimental group. Compared to the control group, theta activity was also induced at the frontal and parietal-central regions, which included the Fz position, and left hemisphere dominance was presented for other exposure durations. The pattern recorded for 10 min of exposure appeared to be brain functions of a meditative state. Moreover, tension factor of BRUMS was decreased in experimental group compared to control group which resembled the meditation effect. Thus, a 6-Hz binaural beat on a 250 Hz carrier tone was suggested as a stimulus for inducing a meditative state. PMID:28701912

Brain Responses to a 6-Hz Binaural Beat: Effects on General Theta Rhythm and Frontal Midline Theta Activity.

PubMed

Jirakittayakorn, Nantawachara; Wongsawat, Yodchanan

2017-01-01

A binaural beat is a beat phenomenon that is generated by the dichotic presentation of two almost equivalent pure tones but with slightly different frequencies. The brain responses to binaural beats remain controversial; therefore, the aim of this study was to investigate theta activity responses to a binaural beat by controlling factors affecting localization, including beat frequency, carrier tone frequency, exposure duration, and recording procedure. Exposure to a 6-Hz binaural beat on a 250 Hz carrier tone for 30 min was utilized in this study. Quantitative electroencephalography (QEEG) was utilized as the recording modality. Twenty-eight participants were divided into experimental and control groups. Emotional states were evaluated by Brunel Mood Scale (BRMUS) before and after exposing to the stimulus. The results showed that theta activity was induced in the entire cortex within 10 min of exposure to the stimulus in the experimental group. Compared to the control group, theta activity was also induced at the frontal and parietal-central regions, which included the Fz position, and left hemisphere dominance was presented for other exposure durations. The pattern recorded for 10 min of exposure appeared to be brain functions of a meditative state. Moreover, tension factor of BRUMS was decreased in experimental group compared to control group which resembled the meditation effect. Thus, a 6-Hz binaural beat on a 250 Hz carrier tone was suggested as a stimulus for inducing a meditative state.

Sealing ability of white and gray mineral trioxide aggregate mixed with distilled water and 0.12% chlorhexidine gluconate as a root end filling material: an ex vivo evaluation.

PubMed

Shetty, K Harish Kumar; Prathap, M S; Prithviraj, K J

2013-01-01

The aim of this study was to evaluate the sealing ability of white and gray mineral trioxide aggregate (MTA) mixed with distilled water and 0.12% chlorhexidine (CHX) gluconate when used as a root-end filling material using the dye-penetration technique. A total of 48 single-rooted human teeth were cleaned, shaped, and obturated with gutta-percha and AH Plus sealer. The apical 3 mm of each root was resected, and 3-mm deep root-end cavity preparations were made. The teeth were randomly divided into 4 experimental groups, each containing 8 teeth, and 2 negative and positive control groups, each containing 8 teeth. Root-end cavities in the experimental groups were filled with the experimental materials. After application of nail polish, the teeth were exposed to India ink for 72 h and longitudinally sectioned, and the extent of dye penetration was measured with a stereomicroscope. No statistically significant differences were observed in the sealing ability of gray and white MTA mixed with distilled water and 0.12% CHX. CHX appears to be a good alternative to replace distilled water, as a solution to be mixed with MTA.

[Effects of acute infrasound exposure on vestibular and auditory functions and the ultrastructural changes of inner ear in the guinea pig].

PubMed

Feng, B; Jiang, S; Yang, W; Han, D; Zhang, S

2001-02-01

To define the effects of acute infrasound exposure on vestibular and auditory functions and the ultrastructural changes of inner ear in guinea pigs. The animals involved in the study were exposed to 8 Hz infrasound at 135dB SPL for 90 minutes in a reverberant chamber. The sinusoidal pendular test (SPT), auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE) were respectively detected pre-exposure and at 0(within 2 hrs), 2 and 5 day after exposure. The ultrastructures of the inner ear were observed by scanning electron microscopy. The slow-phase velocity and the frequency of the vestibular nystagmus elicited by sinusoidal pendular test (SPT) declined slightly following infrasound exposure, but the changes were not significant (P > 0.05). No differences in the ABR thresholds, the latencies and the interval peak latencies of I, III, V waves were found between the normal and the experimental groups, and among experimental groups. The amplitudes of DPOAE at any frequency declined remarkably in all experimental groups. The ultrastructures of the inner ear were damaged to different extent. Infrasound could transiently depress the excitability of the vestibular end-organs, decrease the function of OHC in the organ of Corti and cause damage to the inner ear of guinea pigs.

Hyperbaric pressure effects measured by growth of a transplantable tumor in the C3H/HeN mouse.

PubMed

Herndon, B L; Lally, J J

1984-09-01

Both hypobaric exposure at 0.5 atmospheres absolute (ATA) and hyperbaric pressure exposure at 3.5-8 ATA slowed transplantable tumor growth. These experiments detailed the hyperbaric pressure exposure. C3H/HeN-MTV+ mice, bearing the 16/C transplantable murine mammary adenocarcinoma and exposed to 18 days' treatment by a hyperbaric chamber at 3.5-8 ATA, had tumor weights that averaged 50-75% less than the tumor weights in mice caged at ambient ("sea level") pressure. A series of experiments was run to investigate this response to hyperbaric pressure exposure. After mice underwent continuous exposure to 3.5-8 ATA normoxic (normal oxygen) hyperbaric pressure with use of either argon or nitrogen inert gas, which began 3 days after tumor inoculation, tumors were removed at about 3 weeks' growth from these pressure-exposed mice and measured for growth by weighing. Final tumor weight in pressure-exposed experimental mice was significantly less than tumor weight in paired groups of tumor-bearing controls that received no hyperbaric pressure. Tumor weight was inversely related to pressure "dose," although the small pressure range produced an effect at all pressures used. The number of compression-decompression cycles to which the animals were subjected, however, was related positively to tumor weight at necropsy. Continued tumor growth in mice subjected to frequent pressure change (in conjunction with pressure exposure that otherwise limited tumor size) was unexplained by these experiments. The greatest difference between tumor weights in controls and pressure-exposed animals was seen with 2 weeks' continuous pressure exposure. A limited profile of blood tests was performed, and these reflected only minor, expected change in the pressure-exposed experimental animals. The data at hand did not suggest a mechanism by which chronic normoxic hyperbaric pressure limited tumor size.

Locomotion speed of the benthic foraminifer Ammonia tepida exposed to different nitrogen and carbon sources

NASA Astrophysics Data System (ADS)

Jauffrais, Thierry; Jesus, Bruno; Geslin, Emmanuelle; Briand, Floriane; Jézéquel, Véronique Martin

2016-12-01

Ammonia tepida is a dominant benthic foraminifer colonizing intertidal mudflat sediments. Horizontal locomotion speeds were monitored using time-lapse image analysis over 6 and 24 h. Experimental conditions were based on foraminifera exposed to dry sediment re-suspended in artificial sea water (ASW) without any nutrient addition (condition DS), to combusted sediment re-suspended in in ASW also without any nutrient addition (condition CS), or to combusted sediment re-suspended in ASW enriched with either: nitrate, urea, glucose, soil extract (SE), extracellular polymeric substances (EPS), benthic diatoms (Entomoneis paludosa) or natural microphytobenthic assemblages (MPB). Significant differences were already measured after 6 h between A. tepida mean locomotion speeds at the different experimental conditions. However, differences were clearer after 24 h where the slowest A. tepida mean locomotion speed was measured in specimens placed in CS (1.00 ± 0.30 mm h- 1) and the highest mean locomotion speed in DS (2.99 ± 0.22 mm h- 1). Three different groups were defined according to their locomotion speed, (1) foraminifera exposed to DS had a locomotion speed significantly higher than all other conditions, (2) foraminifera placed in conditions enriched in SE, Glucose, Urea and EPS had intermediary locomotion speeds (1.8-2.5 mm h- 1), and (3) conditions with foraminifera showing the lowest locomotion speeds (1-1.6 mm h- 1) were CS, nitrate, MPB and E. paludosa. Thus, foraminifera exposed to organic matter (DS, SE, Glucose and Urea) showed faster locomotion speeds than foraminifera exposed to inorganic matter (CS, nitrate) or live preys (E. paludosa, MPB). Dissolved organic matter enrichment enhanced foraminifera locomotion speed, which might be a behavioural response to satisfy their carbon and/or nitrogen requirements, and the lowest locomotion speed observed when feeding on live preys might be a consequence of longer time required for live prey phagocytosis.

Radiofrequency electromagnetic radiation from cell phone causes defective testicular function in male Wistar rats.

PubMed

Oyewopo, A O; Olaniyi, S K; Oyewopo, C I; Jimoh, A T

2017-12-01

Cell phones have become an integral part of everyday life. As cell phone usage has become more widespread, concerns have increased regarding the harmful effects of radiofrequency electromagnetic radiation from these devices. The current study was undertaken to investigate the effects of the emitted radiation by cell phones on testicular histomorphometry and biochemical analyses. Adult male Wistar rats weighing 180-200 g were randomly allotted to control, group A (switched off mode exposure), group B (1-hr exposure), group C (2-hr exposure) and group D (3-hr exposure). The animals were exposed to radiofrequency electromagnetic radiation of cell phone for a period of 28 days. Histomorphometry, biochemical and histological investigations were carried out. The histomorphometric parameters showed no significant change (p < .05) in the levels of germinal epithelial diameter in all the experimental groups compared with the control group. There was no significant change (p < .05) in cross-sectional diameter of all the experimental groups compared with the control group. Group D rats showed a significant decrease (p ˂ .05) in lumen diameter compared with group B rats. There was an uneven distribution of germinal epithelial cells in groups B, C and D. However, there was degeneration of the epithelia cells in group D when compared to the control and group B rats. Sera levels of malondialdehyde (MDA) and superoxide dismutase (SOD), which are markers of reactive oxygen species, significantly increased (MDA) and decreased (SOD), respectively, in all the experimental groups compared with the control group. Also sera levels of gonadotropic hormones (FSH, LH and testosterone) significantly decreased (p < .05) in groups C and D compared with the control group. The study demonstrates that chronic exposure to radiofrequency electromagnetic radiation of cell phone leads to defective testicular function that is associated with increased oxidative stress and decreased gonadotropic hormonal profile. © 2017 Blackwell Verlag GmbH.

Buffering and Amplifying Interactions among OAW (Ocean Acidification & Warming) and Nutrient Enrichment on Early Life-Stage Fucus vesiculosus L. (Phaeophyceae) and Their Carry Over Effects to Hypoxia Impact.

PubMed

Al-Janabi, Balsam; Kruse, Inken; Graiff, Angelika; Winde, Vera; Lenz, Mark; Wahl, Martin

2016-01-01

Ocean acidification and warming (OAW) are occurring globally. Additionally, at a more local scale the spreading of hypoxic conditions is promoted by eutrophication and warming. In the semi-enclosed brackish Baltic Sea, occasional upwelling in late summer and autumn may expose even shallow-water communities including the macroalga Fucus vesiculosus to particularly acidified, nutrient-rich and oxygen-poor water bodies. During summer 2014 (July-September) sibling groups of early life-stage F. vesiculosus were exposed to OAW in the presence and absence of enhanced nutrient levels and, subsequently to a single upwelling event in a near-natural scenario which included all environmental fluctuations in the Kiel Fjord, southwestern Baltic Sea, Germany (54°27 ´N, 10°11 ´W). We strove to elucidate the single and combined impacts of these potential stressors, and how stress sensitivity varies among genetically different sibling groups. Enhanced by a circumstantial natural heat wave, warming and acidification increased mortalities and reduced growth in F. vesiculosus germlings. This impact, however, was mitigated by enhanced nutrient conditions. Survival under OAW conditions strongly varied among sibling groups hinting at a substantial adaptive potential of the natural Fucus populations in the Western Baltic. A three-day experimental upwelling caused severe mortality of Fucus germlings, which was substantially more severe in those sibling groups which previously had been exposed to OAW. Our results show that global (OAW), regional (nutrient enrichment) and local pressures (upwelling), both alone and co-occurring may have synergistic and antagonistic effects on survival and/or growth of Fucus germlings. This result emphasizes the need to consider combined stress effects.

Brainstem Auditory Evoked Potential in HIV-Positive Adults.

PubMed

Matas, Carla Gentile; Samelli, Alessandra Giannella; Angrisani, Rosanna Giaffredo; Magliaro, Fernanda Cristina Leite; Segurado, Aluísio C

2015-10-20

To characterize the findings of brainstem auditory evoked potential in HIV-positive individuals exposed and not exposed to antiretroviral treatment. This research was a cross-sectional, observational, and descriptive study. Forty-five HIV-positive individuals (18 not exposed and 27 exposed to the antiretroviral treatment - research groups I and II, respectively - and 30 control group individuals) were assessed through brainstem auditory evoked potential. There were no significant between-group differences regarding wave latencies. A higher percentage of altered brainstem auditory evoked potential was observed in the HIV-positive groups when compared to the control group. The most common alteration was in the low brainstem. HIV-positive individuals have a higher percentage of altered brainstem auditory evoked potential that suggests central auditory pathway impairment when compared to HIV-negative individuals. There was no significant difference between individuals exposed and not exposed to antiretroviral treatment.

Effects of silk fibroin in murine dry eye

NASA Astrophysics Data System (ADS)

Kim, Chae Eun; Lee, Ji Hyun; Yeon, Yeung Kyu; Park, Chan Hum; Yang, Jaewook

2017-03-01

The study aimed to investigate the effects of silk fibroin in a mouse model of dry eye. The experimental dry eye mouse model was developed using more than twelve-weeks-old NOD.B10.H2b mice exposing them to 30-40% ambient humidity and injecting them with scopolamine hydrobromide for 10 days. Tear production and corneal irregularity score were measured by the instillation of phosphate buffered saline or silk fibroin. Corneal detachment and conjunctival goblet cell density were observed by hematoxylin and eosin or periodic acid Schiff staining in the cornea or conjunctiva. The expression of inflammatory markers was detected by immunohistochemistry in the lacrimal gland. The silk group tear production was increased, and corneal smoothness was improved. The corneal epithelial cells and conjunctival goblet cells were recovered in the silk groups. The expression of inflammatory factors was inhibited in the lacrimal gland of the silk group. These results show that silk fibroin improved the cornea, conjunctiva, and lacrimal gland in the mouse model of dry eye. These findings suggest that silk fibroin has anti-inflammatory effects in the experimental models of dry eye.

Psychological Effect of an Analogue Traumatic Event Reduced by Sleep Deprivation.

PubMed

Porcheret, Kate; Holmes, Emily A; Goodwin, Guy M; Foster, Russell G; Wulff, Katharina

2015-07-01

To examine the effect of sleep deprivation compared to sleep, immediately after experimental trauma stimuli on the development of intrusive memories to that trauma stimuli. Participants were exposed to a film with traumatic content (trauma film). The immediate response to the trauma film was assessed, followed by either total sleep deprivation (sleep deprived group, N = 20) or sleep as usual (sleep group, N = 22). Twelve hours after the film viewing the initial psychological effect of the trauma film was measured and for the subsequent 6 days intrusive emotional memories related to the trauma film were recorded in daily life. Academic sleep laboratory and participants' home environment. Healthy paid volunteers. On the first day after the trauma film, the psychological effect as assessed by the Impact of Event Scale - Revised was lower in the sleep deprived group compared to the sleep group. In addition, the sleep deprived group reported fewer intrusive emotional memories (mean 2.28, standard deviation [SD] 2.91) compared to the sleep group (mean 3.76, SD 3.35). Because habitual sleep/circadian patterns, psychological health, and immediate effect of the trauma film were similar at baseline for participants of both groups, the results cannot be accounted for by pre-existing inequalities between groups. Our findings suggest that sleep deprivation on one night, rather than sleeping, reduces emotional effect and intrusive memories following exposure to experimental trauma. © 2015 Associated Professional Sleep Societies, LLC.

[Protective Effect of S-isopentenyl-L-cysteine against DNA Damage in Irradiated Mice].

PubMed

Zheng, Qi-sheng; Yu, Guang-yun; He, Xin; Jiang, Ming; Chu, Xiao-fei; Zhao, Shu-yi; Fan, Sai-jun; Liu, Pei-xun

2015-10-01

To evaluate the protective effect of S-isopentenyl-L-cysteine,a new cysteine derivative,on DNA damage induced by radiation by using acute radiation injury animal models. Forty ICR mice were randomly divided into five groups:the control group,1.0Gy gamma irradiation group,1.0Gy gamma irradiation combined with S-isopentenyl-L-cysteine group,7.2Gy gamma irradiation group,and 7.2Gy gamma irradiation combined with S-isopentenyl-L-cysteine group,with 8 mice in each group.The comet assay and bone marrow polychromatic micronucleus experiments were performed to evaluate the double-strand DNA breaks in ICR mice exposed to 1.0 and 7.2Gy gamma-ray, respectively. The tail DNA percentage,tail length,tail moment,and olive tail moment of peripheral blood lymphocytes in 7.2Gy gamma irradiation group were significantly higher than that of the control group (P<0.01).And it was also observed that above experimental indexes of 7.2Gy gamma irradiation combined with S-isopentenyl-L-cysteine group was significantly less than that of 7.2Gy gamma irradiation group (P<0.05). In addition,the micronucleus rate of 1.0Gy gamma irradiation group and 7.2Gy gamma irradiation group were both significantly higher than in the control group (P<0.01). In addition,in mice given S-isopentenyl-L-cysteine before irradiation,the micronucleus rate of ICR mice exposed to 1.0 and 7.2Gy gamma-ray decreased from (39.5000 ± 3.3141)‰ to (28.1667±4.1345)‰ (P=0.033) and from (76.5000 ± 4.6242)‰ to (22.8333 ± 3.6553)‰(P=0.000),respectively. The bone marrow polychromatic micronucleus experiment indicated that the value of polychromatic erythrocyte (PCE)/normochromatic erythrocyte(NCE) of ICR mice exposed to 1.0 and 7.2Gy gamma-ray was less than the control group(P<0.05). Meanwhile,after irradiating by certain dose,the value of PCE/NCE in mice given S-isopentenyl-L-cysteine before irradiation was significantly higher than the corresponding groups (P<0.05). S-isopentenyl-L-cysteine has a good protective effect against DNA damage induced by radiation.

Antibacterial Efficacy of Octenisept, Alexidine, Chlorhexidine, and Sodium Hypochlorite against Enterococcus faecalis Biofilms.

PubMed

Bukhary, Sundus; Balto, Hanan

2017-04-01

The purpose of this study was to evaluate the antibacterial effectiveness of Octenisept (OCT; Schülke & Mayr GmBH, Norderstedt, Germany), 1% alexidine (ALX) (Santa Cruz Biotechnology, Inc, Santa Cruz, CA), and 2% chlorhexidine (CHX) against Enterococcus faecalis biofilm using confocal laser scanning microscopy. Root dentin discs were prepared from extracted human teeth, sterilized, and inoculated with E. faecalis strain (ATCC 29212) to establish 3-week-old biofilm model. Infected dentin discs were exposed to OCT (n = 20), 1% ALX (n = 20), and 2% CHX (n = 20) for 10 minutes. Dentin discs (n = 15) exposed to 5.25% sodium hypochlorite (NaOCl) were used as a positive control, whereas specimens exposed to saline (n = 15) were used as a negative control. After exposure, the dentin discs were stained with fluorescent LIVE/DEAD BacLight dye (Invitrogen Molecular Probes, Eugene, OR) and analyzed with confocal laser scanning microscopy to determine the proportion of dead cells in the biofilm. Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney U tests (P < .05). The highest proportion of dead cells was found in the 5.25% NaOCl group (94.14%; range, 92.30%-98.20%) compared with the experimental groups (P < .05). A significantly greater proportion of dead cells was found in the OCT group (74.14%; range, 70.03%-78.96%) compared with the 1% ALX and 2% CHX groups (P < .05). The proportion of dead cells was 43.89% (range, 24.86%-55.63%) and 42.78% (range, 25.45%-55.06%) in the 1% ALX and 2% CHX groups, respectively, with no statistical significant difference between the 2 groups (P > .05). NaOCl had significantly greater antimicrobial activity against E. faecalis biofilms compared with OCT, CHX, and ALX. OCT was more effective than CHX and ALX. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effects of seminal plasma and flash-freezing on DNA structure of stallion epididymal sperm exposed to different potentiators of DNA damage.

PubMed

Serafini, R; Varner, D D; Blanchard, T L; Teague, S R; LaCaze, K; Love, C C

2018-05-24

The tolerance of sperm DNA structure to seminal plasma and freezing conditions has both clinical and basic biologic relevance. In this study, fresh (FS) or flash-frozen (FZ) stallion epididymal sperm were exposed (SP + ) or unexposed (SP - ) to seminal plasma. Sperm were then evaluated to monitor the degree of change in DNA structure following challenge with chemical (dithiothreitol-DTT), oxidative (iron sulfate; FeSO 4 ) or enzymatic (DNase I) potentiators of DNA damage. For sperm not treated with potentiators (controls), there was no effect of SP treatment (SP - vs. SP + ) or freezing treatment (FS vs. FZ; non-significant) on measures of any DNA assays (i.e., 8-hydroxy, 2'deoxyguanosine [8OHdG], TUNEL, or sperm chromatin structure [SCSA] assays). Group FZ was more susceptible than Group FS to potentiators of DNA damage. Percent 8OHdG-positive sperm was higher in Group FZ/SP - treated with FeSO 4 than all other groups (P < 0.05). Percent TUNEL-positive sperm was similar among FZ/SP - groups treated with DTT, FeSO 4 , or DNase (non-significant) and was higher in these groups than all other treatments (P < 0.05). Percent COMP-α t was higher following treatment with DNase or DTT, as compared to their respective controls, regardless of prior exposure to SP (P < 0.05). Overall, sperm DNA structure was unaffected by seminal plasma or freezing treatment when samples were not exposed to potentiators of sperm DNA damage; however, marked differences were identified in DNA structure when sperm were challenged with chemical, oxidative or enzymatic treatments. These results highlight the importance of challenging DNA structure prior to analysis. The use of potentiators of DNA damage provided a model to evaluate sperm DNA structure following exposure of sperm to various experimental treatments. Copyright © 2018 Elsevier Inc. All rights reserved.

Adolescent environmental enrichment prevents behavioral and physiological sequelae of adolescent chronic stress in female (but not male) rats.

PubMed

Smith, Brittany L; Morano, Rachel L; Ulrich-Lai, Yvonne M; Myers, Brent; Solomon, Matia B; Herman, James P

2017-11-22

The late adolescent period is characterized by marked neurodevelopmental and endocrine fluctuations in the transition to early adulthood. Adolescents are highly responsive to the external environment, which enhances their ability to adapt and recover from challenges when given nurturing influences, but also makes them vulnerable to aberrant development when exposed to prolonged adverse situations. Female rats are particularly sensitive to the effects of chronic stress in adolescence, which manifests as passive coping strategies and blunted hypothalamo-pituitary adrenocortical (HPA) stress responses in adulthood. We sought to intervene by exposing adolescent rats to environmental enrichment (EE) immediately prior to and during chronic stress, hypothesizing that EE would minimize or prevent the long-term effects of stress that emerge in adult females. To test this, we exposed male and female rats to EE on postnatal days (PND) 33-60 and implemented chronic variable stress (CVS) on PND 40-60. CVS consisted of twice-daily unpredictable stressors. Experimental groups included: CVS/unenriched, unstressed/EE, CVS/EE and unstressed/unenriched (n = 10 of each sex/group). In adulthood, we measured behavior in the open field test and forced swim test (FST) and collected blood samples following the FST. We found that environmental enrichment given during the adolescent period prevented the chronic stress-induced transition to passive coping in the FST and reversed decreases in peak adrenocortical responsiveness observed in adult females. Adolescent enrichment had little to no effect on males or unstressed females tested in adulthood, indicating that beneficial effects are specific to females that were exposed to chronic stress.

[Comparative study of nanosized and microsized silicon dioxide on spermatogenesis function of male rats].

PubMed

Fan, Yi-Ou; Zhang, Ying-Hua; Zhang, Xiao-Peng; Liu, Bing; Ma, Yi-xin; Jin, Yi-he

2006-09-01

To compare the effects of nanosized and microsized silicon dioxide on spermatogenesis function of male rats exposed by inhalation. 45 male rats were randomly divided into control group and four experimental groups which were exposed by 100 mg/m3 or 300 mg/m3 nanosized and microsized silicon dioxide in inhalation chambers 2 hours every other day. Age-matched rats were exposed to room air with the same condition and served as controls. 65 days later, the testicular and epididymal viscera coefficients, the quantity and quality of sperm were examined and the histopathological assessment was done. The changes in biochemical parameters in serum and testes were also measured. Nanosized silicon dioxide could induce histopathological changes of testes in rats, and the effect was higher than that of microsized particles at the same concentration. Nanosized silicon dioxide could reduce the sperm counts of rats and the testicular LDH-C4 activities, increase MDA levels in the testes and the effect was higher than that of microsized particles at the same concentration. Nanosized silicon dioxide could lead to the reduction of sperm motility, testicular LDH-C4 activities and 8-hydroxydeoxyguanosine (8-OHdG) concentration in serum elevation in particles-exposed rats compared with the control animals, but there are no significant difference compared with that of microsized particles at the same concentration. The present findings suggest a different effect of impairment of sperm production and maturation induced by inhalation of nanosized and microsized silicon dioxide, and nanosized silicon dioxide exerted more severe reaction.

[Oxidative damage and immunotoxicity effect of people who exposed to electronic waste].

PubMed

Zhang, Ronghua; Xu, Caiju; Shen, Haitao; Tang, Yun; Meng, Jia; Lu, Wei; Wang, Xiaofeng; Lou, Xiaoming; Song, Yanhua; Han, Guangen; Cai, Delei; Ding, Gangqiang

2012-03-01

To investigate the relationship between risk factors and the effects of antioxidation and immune function in adults who exposed to electronic waste( e-waste). The exposed group was chosen from the people who lived in the e-waste disposing areas of Zhejiang province. The control group was chosen from people who lived in unpolluted area. Anticoagulation and coagulation peripheral venous blood samples were collected from 40 exposed persons (22 employees, 18 non-employees) and 36 exposed persons respectively. The oxidative, immune, Cd, Pb, Cr, Hg, and PCB indexes were detected. The contents of Cd, total PCB, MDA statistically increased in exposed group comparing with the control group (P < 0.05). The activity of SOD, GSH-Px, the percentage of helper/inducer T lymphocytes (CD4+) and the content of Cr in exposed group were less than those in the controlgroup (P < 0.05). Oxidative damage and immunotoxicity were observed in the group that lived in e-waste disposing areas. These effects were mainly related to the increase of Cd content or Cd and Pb contents in peripheral venous blood.

The effect of violent and nonviolent video games on heart rate variability, sleep, and emotions in adolescents with different violent gaming habits.

PubMed

Ivarsson, Malena; Anderson, Martin; Åkerstedt, Torbjörn; Lindblad, Frank

2013-05-01

To study cardiac, sleep-related, and emotional reactions to playing violent (VG) versus nonviolent video games (NVG) in adolescents with different gaming habits. Thirty boys (aged 13-16 years, standard deviation = 0.9), half of them low-exposed (≤1 h/d) and half high-exposed (≥3 h/d) to violent games, played a VG/NVG for 2 hours during two different evenings in their homes. Heart rate (HR) and HR variability were registered from before start until next morning. A questionnaire about emotional reactions was administered after gaming sessions and a sleep diary on the following mornings. During sleep, there were significant interaction effects between group and gaming condition for HR (means [standard errors] for low-exposed: NVG 63.8 [2.2] and VG 67.7 [2.4]; for high-exposed: NVG 65.5 [1.9] and VG 62.7 [1.9]; F(1,28) = 9.22, p = .005). There was also a significant interaction for sleep quality (low-exposed: NVG 4.3 [0.2] and VG 3.7 [0.3]); high-exposed: NVG 4.4 [0.2] and VG 4.4 [0.2]; F(1,28) = 3.51, p = .036, one sided), and sadness after playing (low-exposed: NVG 1.0 [0.0] and VG 1.4 [0.2]; high-exposed: NVG 1.2 [0.1] and VG 1.1 [0.1]; (F(1,27) = 6.29, p = .009, one sided). Different combinations of the extent of (low versus high) previous VG and experimental exposure to a VG or an NVG are associated with different reaction patterns-physiologically, emotionally, and sleep related. Desensitizing effects or selection bias stand out as possible explanations.

[Evoked potentials and psychometric tests in the diagnosis of subclinical neurological damage in a group of workers exposed to low concentrations of mercury vapor].

PubMed

Martínez Vázquez, C; Rodríguez Sáez, E; Gil Fernández, M; Torres Pombo, J; Rodríguez, M; Iglesias Groba, M T; Herves Beloso, C

1996-05-01

We study the effects of low concentrations of mercury vapour on the nervous system of a group of eleven workers of a chloroalkali plant exposed to it. Twenty-three non-exposed workers in the same factory were used as control group. We used clinical and analytic explorations, psychometric tests and evoked potentials to evaluate the subjects. The average Hg in urine of the exposed group was 41.74 micrograms/gr creatinine and the average of the non-exposed group as 9.71 mu/yr. In the exposed group the evoked potentials have found a slowing-down of conduction in all the nervous paths studied (optical, auditive and somatosensory) and in the latency of P300 wave, although this was not statistically significant compared to the control group. Of the psychometric test used, only Rey's Complex Figure Test showed deterioration in the visual memory subtest of the exposed group (p < 0.05) compared to the control group, although in Wechsler's digit span test lower scores were obtained which were close to being statistically significant comparing the averages of the two groups (0.05 < p < 0.051). Bearing in mind these results we think that the amounts of Hg in urine and TLV-TWA (50 micrograms/gr creatinine and 50 micrograms/m3 respectively) accepted by most authors as innocuous should be reduced.

Efficacy of a Transition Theory-Based Discharge Planning Program for Childhood Asthma Management.

PubMed

Ekim, Ayfer; Ocakci, Ayse Ferda

2016-02-01

This study tested the efficacy of a nurse-led discharge planning program for childhood asthma management, based on transition theory. A quasi-experimental design was used. The sample comprised 120 children with asthma and their parents (intervention group n = 60, control group n = 60). The asthma management self-efficacy perception level of parents in the intervention group increased significantly and the number of triggers their children were exposed to at home was reduced by 60.8%. The rates of admission to emergency departments and unscheduled outpatient visits were significantly lower in the intervention group compared with the control group. Transition theory-based nursing interventions can provide successful outcomes on childhood asthma management. Transition theory-based discharge planning program can guide nursing interventions to standardize care of the child with asthma. Combining care at home with hospital care strengthens ongoing qualified asthma management. © 2015 NANDA International, Inc.

[Neuromodulatory effects of bromazepam when individuals were exposed to a motor learning task: quantitative electroencephalography (qEEG)].

PubMed

Salles, José Inácio; Bastos, Victor Hugo; Cunha, Marlo; Machado, Dionis; Cagy, Maurício; Furtado, Vernon; Basile, Luis Fernando; Piedade, Roberto; Ribeiro, Pedro

2006-03-01

The sedative effects of bromazepam on cognitive and performance have been widely investigated. A number of different approaches have assessed the influence of bromazepam when individuals are engaged to a motor task. In this context, the present study aimed to investigate electrophysiological changes when individuals were exposed to a typewriting task after taking 6 mg of bromazepam. qEEG data were simultaneously recorded during the task. In particular, relative power in delta band (0.5-3.5 Hz) was analyzed. Time of execution and errors during the task were registered as behavioral variables. The experimental group, bromazepam 6 mg, showed a better motor performance and higher relative power than control individuals (placebo). These results suggest that the use of bromazepam reduces anxiety levels as expected and thus, produces an increment in motor performance.

Influence of short term exposure of TBT on the male reproductive activity in freshwater prawn Macrobrachium rosenbergii (De Man).

PubMed

Revathi, Peranandam; Iyapparaj, Palanisamy; Vasanthi, Lourduraj Arockia; Munuswamy, Natesan; Prasanna, Vimalanathan Arun; Pandiyarajan, Jayaraj; Krishnan, Muthukalingan

2014-10-01

In the present study, the effect of tributyltin (TBT) on the histopathological and hormonal changes during spermatogenesis in freshwater prawn Macrobrachium rosenbergii was documented. Three experimental concentrations such as 10, 100 and 1,000 ng/L were selected and exposed to prawns for 45 days. After TBT exposure, the reproductive activities like sperm count and sperm length were decreased when compared with control. Further, abnormal structure of the seminiferous tubule, decrease in spermatozoa concentration, diminution of the seminiferous tubule membrane and the abundance of spermatocytes in the testis were noticed in treated prawns. Interestingly, radioimmunoassay clearly revealed the reduction of testosterone level in TBT exposed groups. Thus, TBT has considerably reduced the level of testosterone and caused the impairment of spermatogenesis in the freshwater male prawn M. rosenbergii.

Changes in DNA methylation fingerprint of Quercus ilex trees in response to experimental field drought simulating projected climate change.

PubMed

Rico, L; Ogaya, R; Barbeta, A; Peñuelas, J

2014-03-01

Rapid genetic changes in plants have been reported in response to current climate change. We assessed the capacity of trees in a natural forest to produce rapid acclimation responses based on epigenetic modifications. We analysed natural populations of Quercus ilex, the dominant tree species of Mediterranean forests, using the methylation-sensitive amplified polymorphism (MSAP) technique to assess patterns and levels of methylation in individuals from unstressed forest plots and from plots experimentally exposed to drought for 12 years at levels projected for the coming decades. The percentage of hypermethylated loci increased, and the percentage of fully methylated loci clearly decreased in plants exposed to drought. Multivariate analyses exploring the status of methylation at MSAP loci also showed clear differentiation depending on stress. The PCA scores for the MSAP profiles clearly separated the genetic from the epigenetic structure, and also significantly separated the samples within each group in response to drought. Changes in DNA methylation highlight the large capacity of plants to rapidly acclimate to changing environmental conditions, including trees with long life spans, and our results demonstrate those changes. These changes, although unable to prevent the decreased growth and higher mortality associated with this experimental drought, occurred together with a dampening in such decreases as the long-term treatment progressed. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Differential ontogenetic exposure to obesogenic environment induces hyperproliferative status and nuclear receptors imbalance in the rat prostate at adulthood.

PubMed

Pytlowanciv, Eloísa Zanin; Pinto-Fochi, Maria Etelvina; Reame, Vanessa; Gobbo, Marina Guimarães; Ribeiro, Daniele Lisboa; Taboga, Sebastião Roberto; Góes, Rejane Maira

2016-05-01

Experimental data indicate that high-fat diet (HFD) may alter proliferative activity and prostate health. However, the consequences of HFD exposure during different periods of ontogenetic development on prostate histophysiology remain to be elucidated. Herein, we compare the influence of obesogenic environment (OE) due to maternal obesity and HFD at different periods of life on proliferative activity and nuclear receptors frequency in the rat ventral prostate and a possible relationship with metabolic and hormonal alterations. Male Wistar rats (19 weeks old), treated with balanced chow (Control group-C; 3% high-fat, 3.5 Kcal/g), were compared with those exposed to HFD (20% high-fat, 4.9 kcal/g) during gestation (G-maternal obesity), gestation and lactation (GL), from post-weaning to adulthood (WA), from lactation to adulthood (LA) and from gestation to adulthood (GA). After the experimental period, the ventral prostate lobes were removed and analyzed with different methods. Metabolic data indicated that G and GL rats became insulin resistant and WA, LA, and GA became insulin resistant and obese. There was a strong inverse correlation between serum testosterone (∼133% lower) and leptin levels (∼467% higher) in WA, LA, and GA groups. Estrogen serum levels increased in GA, and insulin levels increased in all groups, especially in WA (64.8×). OE-groups exhibited prostatic hypertrophy, since prostate weight increased ∼40% in G, GL, LA, and GA and 31% in WA. As indicated by immunohistochemistry, all HFD-groups except G exhibited an increase in epithelial cell proliferation (PCNA-positive) and a decrease in frequency of AR- and ERβ-positive epithelial cells; there was also an increment of ERα-positive stromal cells in comparison with control. Cells containing PPARγ increased in both epithelium and stroma of all OE groups and those expressing LXRα decreased, particularly in groups OE-exposed during gestation (G, GL and GA). OE leads to prostate hypertrophy regardless of the period of development and, except when restricted to gestation, leads to a hyperproliferative status which was correlated to downregulation of AR and LXRα and upregulation of ERα and PPARγ signaling. © 2016 Wiley Periodicals, Inc.

The Effects of Stereotactic Cerebroventricular Administration of Albumin, Mannitol, Hypertonic Sodium Chloride, Glycerin and Dextran in Rats with Experimental Brain Edema.

PubMed

Ates, Tuncay; Gezercan, Yurdal; Menekse, Guner; Turkoz, Yusuf; Parlakpinar, Hakan; Okten, Ali Ihsan; Akyuva, Yener; Onal, Selami Cagatay

2017-01-01

To evaluate the effects of cerebroventricular administration of hyperoncotic/hyperosmotic agents on edematous brain tissue in rats with experimental head trauma. The study included 54 female Sprague-Dawley rats with weights ranging between 200 and 250 g. Six experimental groups were examined with each group containing 9 rats. All rats were exposed to head trauma, and treatment groups were administered 2 µl of one of the drugs (albumin, mannitol, hypertonic sodium chloride (NaCl), glycerin and dextran) 6, 12 and 24 hours after the trauma via the cerebroventricular route and using a stereotactic device. Rats were sacrificed 48 hours after the trauma, and brain tissues were extracted without damage. Biochemical analyses including reduced glutathione (GSH), nitric oxide (NO), malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), and interleukin 1 beta (IL-1β) were performed on the injured left hemisphere. Compared with the control group, the albumin, mannitol, 3% NaCl and glycerin treatment groups revealed dramatic increases in GSH levels (p < 0.001). Levels of MDA, which is the end-product of brain edema and lipid peroxidation, failed to show a statistically significant decrease, but there was a decreasing trend observed in the inter-group comparisons. NO levels were also decreased in the 3% NaCl treatment group. An analysis of TNF-α and IL-1β, two proinflammatory cytokines associated with the trauma, revealed that IL-1β decreased significantly in all treatment groups (p=0.001), whereas no significant difference was detected in TNF-α levels. Cerebroventricular administration of hyperoncotic/hyperosmotic agents provides substantial effects on the treatment of brain edema.

The Impact of Sexual Media on Second Language Vocabulary Retrieval.

PubMed

Çetin, Yakup

2015-12-01

Both Islam and Christianity warn their adherents not to view or to display obscene matter. Aside from religious consequences in the afterlife for such behavior, this study was conducted to determine if viewing sexual media has a detrimental effect in earthly life. Adolescents (n = 64) 17-22 years were exposed to two types of visual stimuli containing sexual or neutral content for 30 min. The participants, seated in rooms with comfortable chairs and provided with snacks, were shown a selection of 18 German words via a PowerPoint slideshow, which included a picture, an audio recording, and the written form of each word. The experimental group, which was exposed to arousing visual stimuli with mild sexual content (movie trailers, music video clips, and TV commercials), remembered significantly fewer words than the control group, which viewed a nature documentary without sexual content. T-test scores revealed that exposure to sexually arousing media impaired memory for second language (L2) vocabulary. Apart from leading to dire consequences in the hereafter, the results of the study demonstrate that viewing obscene material also causes harm in this life.

The effectiveness of ultrabrief and brief educational videos for training lay responders in hands-only cardiopulmonary resuscitation: implications for the future of citizen cardiopulmonary resuscitation training.

PubMed

Bobrow, Bentley J; Vadeboncoeur, Tyler F; Spaite, Daniel W; Potts, Jerald; Denninghoff, Kurt; Chikani, Vatsal; Brazil, Paula R; Ramsey, Bob; Abella, Benjamin S

2011-03-01

Bystander cardiopulmonary resuscitation (CPR) improves survival from out-of-hospital cardiac arrest (OHCA) but often is not performed. We hypothesized that subjects viewing very short Hands-Only CPR videos will (1) be more likely to attempt CPR in a simulated OHCA scenario and (2) demonstrate better CPR skills than untrained individuals. This study is a prospective trial of 336 adults without recent CPR training randomized into 4 groups: (1) control (no training) (n=51); (2) 60-second video training (n=95); (3) 5-minute video training (n=99); and (4) 8-minute video training, including manikin practice (n=91). All subjects were tested for their ability to perform CPR during an adult OHCA scenario using a CPR-sensing manikin and Laerdal PC SkillReporting software. One half of the trained subjects were randomly assigned to testing immediately and the other half after a 2-month delay. Twelve (23.5%) controls did not even attempt CPR, which was true of only 2 subjects (0.7%; P=0.01) from any of the experimental groups. All experimental groups had significantly higher average compression rates (closer to the recommended 100/min) than the control group (P<0.001), and all experimental groups had significantly greater average compression depth (>38 mm) than the control group (P<0.0001). Laypersons exposed to very short Hands-Only CPR videos are more likely to attempt CPR and show superior CPR skills than untrained laypersons. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01191736.

Central mechanisms of stress-induced headache.

PubMed

Cathcart, S; Petkov, J; Winefield, A H; Lushington, K; Rolan, P

2010-03-01

Stress is the most commonly reported trigger of an episode of chronic tension-type headache (CTTH); however, the causal significance has not been experimentally demonstrated to date. Stress may trigger CTTH through hyperalgesic effects on already sensitized pain pathways in CTTH sufferers. This hypothesis could be partially tested by examining pain sensitivity in an experimental model of stress-induced headache in CTTH sufferers. Such examinations have not been reported to date. We measured pericranial muscle tenderness and pain thresholds at the finger, head and shoulder in 23 CTTH sufferers (CTH-S) and 25 healthy control subjects (CNT) exposed to an hour-long stressful mental task, and in 23 CTTH sufferers exposed to an hour-long neutral condition (CTH-N). Headache developed in 91% of CTH-S, 4% of CNT, and 17% of CTH-N subjects. Headache sufferers had increased muscle tenderness and reduced pain thresholds compared with healthy controls. During the task, muscle tenderness increased and pain thresholds decreased in the CTH-S group compared with CTH-N and CNT groups. Pre-task muscle tenderness and reduction in pain threshold during task were predictive of the development and intensity of headache following task. The main findings are that stress induced a headache in CTTH sufferers, and this was associated with pre-task muscle tenderness and stress-induced reduction in pain thresholds. The results support the hypothesis that stress triggers CTTH through hyperalgesic effects on already increased pain sensitivity in CTTH sufferers, reducing the threshold to noxious input from pericranial structures.

An accurate density functional theory based estimation of pK(a) values of polar residues combined with experimental data: from amino acids to minimal proteins.

PubMed

Matsui, Toru; Baba, Takeshi; Kamiya, Katsumasa; Shigeta, Yasuteru

2012-03-28

We report a scheme for estimating the acid dissociation constant (pK(a)) based on quantum-chemical calculations combined with a polarizable continuum model, where a parameter is determined for small reference molecules. We calculated the pK(a) values of variously sized molecules ranging from an amino acid to a protein consisting of 300 atoms. This scheme enabled us to derive a semiquantitative pK(a) value of specific chemical groups and discuss the influence of the surroundings on the pK(a) values. As applications, we have derived the pK(a) value of the side chain of an amino acid and almost reproduced the experimental value. By using our computing schemes, we showed the influence of hydrogen bonds on the pK(a) values in the case of tripeptides, which decreases the pK(a) value by 3.0 units for serine in comparison with those of the corresponding monopeptides. Finally, with some assumptions, we derived the pK(a) values of tyrosines and serines in chignolin and a tryptophan cage. We obtained quite different pK(a) values of adjacent serines in the tryptophan cage; the pK(a) value of the OH group of Ser13 exposed to bulk water is 14.69, whereas that of Ser14 not exposed to bulk water is 20.80 because of the internal hydrogen bonds.

Exposure to stallion accelerates the onset of mares' cyclicity.

PubMed

Wespi, B; Sieme, H; Wedekind, C; Burger, D

2014-07-15

Horses (Equus caballus) belong to the group of seasonally polyestrous mammals. Estrous cycles typically start with increasing daylight length after winter, but mares can differ greatly in the timing of onset of regular estrus cycles. Here, we test whether spatial proximity to a stallion also plays a role. Twenty-two anestrous mares were either exposed to one of two stallions (without direct physical contact) or not exposed (controls) under experimental conditions during two consecutive springs (February to April). Ovarian activity was monitored via transrectal ultrasound and stallion's direct contact time with each mare was determined three times per week for one hour each. We found that mares exposed to a stallion ovulated earlier and more often during the observational period than mares that were not exposed to stallions. Neither stallion identity nor direct contact time, mare age, body condition, size of her largest follicle at the onset of the experiment, or parasite burden significantly affected the onset of cyclicity. In conclusion, the timing of estrous cycles and cycle frequency, i.e., crucial aspects of female reproductive strategy, strongly depend on how the mares perceive their social environment. Exposing mares to the proximity of a stallion can therefore be an alternative to, for example, light programs or elaborated hormonal therapies to start the breeding season earlier and increase the number of estrous cycles in horses. Copyright © 2014 Elsevier Inc. All rights reserved.

The influence of microwave radiation from cellular phone on fetal rat brain.

PubMed

Jing, Ji; Yuhua, Zhang; Xiao-qian, Yang; Rongping, Jiang; Dong-mei, Guo; Xi, Cui

2012-03-01

The increasing use of cellular phones in our society has brought focus on the potential detrimental effects to human health by microwave radiation. The aim of our study was to evaluate the intensity of oxidative stress and the level of neurotransmitters in the brains of fetal rats chronically exposed to cellular phones. The experiment was performed on pregnant rats exposed to different intensities of microwave radiation from cellular phones. Thirty-two pregnant rats were randomly divided into four groups: CG, GL, GM, and GH. CG accepted no microwave radiation, GL group radiated 10 min each time, GM group radiated 30 min, and GH group radiated 60 min. The 3 experimental groups were radiated 3 times a day from the first pregnant day for consecutively 20 days, and on the 21st day, the fetal rats were taken and then the contents of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), noradrenaline (NE), dopamine (DA), and 5-hydroxyindole acetic acid (5-HT) in the brain were assayed. Compared with CG, there were significant differences (P<0.05) found in the contents of SOD, GSH-Px, and MDA in GM and GH; the contents of SOD and GSH-Px decreased and the content of MDA increased. The significant content differences of NE and DA were found in fetal rat brains in GL and GH groups, with the GL group increased and the GH group decreased. Through this study, we concluded that receiving a certain period of microwave radiation from cellular phones during pregnancy has certain harm on fetal rat brains.

Preclinical safety evaluation of submicronized sildenafil citrate nebulization solution in small experimental animals.

PubMed

Agrawal, Priyanka; Soni, Sandeep; Mittal, Gaurav; Bhatnagar, Aseem

2015-01-01

Sildenafil citrate (SC) nebulization solution has the potential to treat pulmonary hypertension by delivering high concentration directly to the respiratory system while minimizing systemic drug exposure and associated toxicity. The objective of the present study was to evaluate the potential toxicity of aerosolized SC (inhaled) in Sprague dawley rats for 28 days. The rats were randomly divided into five groups (n = 6). Placebo (normal saline) was inhaled to group I (control). Group II was exposed to therapeutic dose (TD): 20 mg/kg, while group 3 and group 4 were exposed to 3 TD and 6 TD, respectively, till 28 days and toxicokinetic parameters were evaluated in group V. The particle size of the nebulized solution of SC (1%) was measured by using Anderson Cascade Impactor. At the end of experiment, all animals were sacrificed. Endpoints used to evaluate potential toxicity of inhaled sildenafil citrate were clinical observations, body weight, and clinical pathology along with broncho-alveolar lavage (BAL) Fluid investigation. ACI study has shown that more than 70% aerosolized drug particles were in submicron range (0.3-0.5 μm). There was no systemic toxicity or clinically limiting local respiratory toxicity associated with inhalation exposure to SC nebulization solution at 6 TD. No significant changes were observed in the level of different blood and BALF parameters in treated groups in comparison to control. Histopathological examination revealed no abnormal findings in the animals of treated group. The data demonstrate that aerosolized sildenafil citrate is well tolerated in rats and suggest its use in humans.

Urinary Arsenic Metabolites in Children and Adults Exposed to Arsenic in Drinking Water in Inner Mongolia, China

PubMed Central

Sun, Guifan; Xu, Yuanyuan; Li, Xin; Jin, Yaping; Li, Bing; Sun, Xiance

2007-01-01

Background We report the concentrations and distributions of urinary arsenic (As) metabolites in 233 residents exposed to 20, 90, or 160 μg/L inorganic arsenic (iAs) in drinking water from three villages in Hohhot, Inner Mongolia, China, that formed one control and two exposed groups. Methods We used hydride generation-atomic absorption spectrometry (HGAAS) to determine iAs, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). Results The concentrations of each urinary As species in the two exposed groups were significantly higher than in the control group for both children and adults. Both children and adults in exposed groups had higher percent iAs and MMA and lower percent DMA, and low primary and secondary methylation indices (PMI and SMI, respectively) than those in the control group. However, children showed significant increases in percent DMA and the SMI as well as decreases in the percent MMA when the iAs exposure level increased from 90 to 160 μg/L. In addition, children in the two exposed groups showed lower percent MMA but higher percent DMA and higher SMI than adults in the same exposed group. No significant differences in As metabolite concentrations and distributions were found between males and females in each group. A significant correlation was also found in the SMI between 11 pairs of children and their mothers from the 160-μg/L–exposed group. Conclusions Children had higher a capacity for secondary methylation of As than adults when exposed to the same concentrations of iAs in drinking water. Exposure to As may increase the capacity for methylation in children to some extent. PMID:17450238

[Laboratory animals and official Mexican norms (NOM-062-ZOO-1999)].

PubMed

de Aluja, Aline S

2002-01-01

This article concerns animal experimentation and official Mexican norm Nom 0062-Zoo-1999 entitled Technical specifications for the production, care and use of laboratory animals. The history of animal experimentation is briefly resumed. During the nineteenth century, doubts arose as to the right to expose animals to experimental procedures that frequently cause pain and suffering. The first law which protected animals against cruelty was passed in Great Britain in 1876; subsequently, other nations approved similar legislation. During the second part of the twentieth century, opposition to animal experimentation grew. Other groups, mainly scientists and pharmaceutical concerns, defended the right to use animals in research. New knowledge concerning the neurophysiology, cognitive capacity, and the animal faculty to experience pain is briefly mentioned. Guidelines on care and use of animals used in research published in several countries are listed. Finally, the recently published Mexican legislation (Norm) referring to production, care and use of laboratory animals is discussed and its benefits are stressed.

Cardiovascular changes in workers exposed to fine particulate dust.

PubMed

Bortkiewicz, Alicja; Gadzicka, Elżbieta; Stroszejn-Mrowca, Grażyna; Szyjkowska, Agata; Szymczak, Wiesław; Koszada-Włodarczyk, Wiesława; Szadkowska-Stańczyk, Irena

2014-01-01

Epidemiological studies provide evidence that airborne particulate matter may contribute to the increased incidence and mortality rates due to pulmonary and cardiovascular diseases. Only some of them address the problem of occupational exposure to particulate air pollution. The aim of our study was to assess cardiovascular reaction and autonomic regulation in workers exposed to fine particles. All workers had medical examination, resting ECG with heart rate variability analysis (HRV), 24-h ECG, and ambulatory blood pressure monitoring (ABPM) performed. The subjects were 20 male workers (mean age: 32.14.0 year) of a ceramic ware factory exposed to the dust and 20 workers who were not exposed (mean age: 39.4±7.8 year). The period of employment under exposure amounted to 5.6±2.1 year. Dust exposure was measured using individual dosimeters. The geometric mean total dust concentration was 44±1.5 mg/m(3) and the FPD (fine particulate dust) concentration amounted to 11.5±1.6 mg/m(3). No abnormalities were noted in the resting ECG in both groups, in 24-h ECG 2 subjects, both from exposed and control groups, had ventricular heart rhythm and repolarization disturbances. Blood pressure in ABPM, both systolic as well as diastolic, was normal and did not differ between the groups. Resting heart rate in the exposed group was significantly lower (p = 0.038) than in the control group. In the exposed group STD R-R from short-term records was significantly higher (p = 0.01). Fast Fourier Transform (FFT) analysis showed that the low frequency power spectrum (LF) did not differ in the exposed and the control group, while high frequency (HF) was significantly higher in the exposed group. LF/HF ratio was significantly lower in the exposed in comparison with the control group. Although we did not reveal significant abnormalities in ECG as well as in ABPM in the exposed group, it seems that neurovegetative disturbances (parasympathetic predominance) may serve as an early indicator of fine particulate dust effect on cardiovascular system.

Histopathological changes in the liver of rabbits exposed to high nitrate ingestion in drinking water.

PubMed

Sharma, Manoj Kumar; Sharma, Hemlata; Bapna, Neelam

2013-08-01

In India, especially in Rajasthan, people drink water which contains high level of nitrates and the possibility of finding concentrations of up to 500 mg of nitrate ions per litre of water is not unusual. Excessive use of nitrate fertilisers and herbicides results in accumulation of nitrate in plants and methemoglobinaemia in cattle as consequences of nitrate poisoning. The ingested nitrate is converted to nitrite in the digestive system and it is absorbed in blood, thus causing methemoglobinaemia. Methaemoglobinaemia is not restricted to infants alone, but it is prevalent in higher age groups also. Therefore, an experimental study was conducted on 10 rabbits which were between three and a half months to four months of age, which had weights which ranged from 1.310 kg to 1.720 kg. Five groups A, B, C,D and E were formed, with two rabbits in each group. The control Group A was given water orally, which had 45 mg/litres of nitrate. Groups B to E (experimental groups) were administered water orally, which had concentrations of 100mg/litre, 200mg/litre, 400mg/litre and 500mg/litre of nitrate respectively, for 120 days. During experimental period, the differences in general behaviour of rabbits were noted. After this, rabbits were anaesthetised and sacrificed according to guidelines of ICMR and their livers were removed and processed for making paraffin sections,.Hematoxyllin and eosin staining was done for microscopic observations. During experimental period, the animals were found to be lethargic on 75(th) day. Quantity of intake of food and water was not altered in the rabbits which were undergoing experiments in different groups. Rabbits of all groups i.e. A to E showed a continuous increase in heart rate (up to 218/minute in Group E) and respiration rate (up to 84/minute in Group E) respectively. The microscopic study showed mild necrosis of hepatocytes, with infiltration of inflammatory cells in between hepatocytes. In higher groups, the liver showed bridging necrosis and portal triditis. Dilatations of central vein with eosinophilic degeneration were observed in Group E only.

An examination of student attitudes and understanding of exponential functions using interactive instructional multimedia

NASA Astrophysics Data System (ADS)

Singleton, Cynthia M.

The purpose of this study was to examine students' attitudes and understanding of exponential functions using InterAct Math, a mathematics tutorial software. The researcher used a convenience sampling of a total of 78 students from two intact pre-calculus classes; the students in the experimental group totaled 41 and the control group totaled 37. The two groups were exposed to the same curriculum content taught by the same instructor, the researcher. The experimental group used the mathematics tutorial software as an integral part of the instructional delivery. The control group used traditional instruction without integration of the educational technology. Data were collected during a two week span using a mixed-methodology to address the major research questions: (1) Is there a statistically significant difference in the mean achievement test scores between the experimental and the control groups? (2) Is there a statistically significant difference in students' attitudes toward learning mathematics between the experimental group and the control group? The researcher utilized paired t-tests and independent t-tests as statistical methods to evaluate the effectiveness of the intervention and to establish whether there was a significant difference between the experimental and control groups. Based on the analyses of the quantitative data, it was established that the students who received the InterAct Math tutorial (experimental group) did not perform better than the control group on exponential functions, graphs and applications. However, the quantitative part of the study (Aiken-Dreger Mathematics Attitude Scale) revealed that, while students in the experimental and control groups started with similar attitudes about mathematics and the integration of technology, their attitudes were significantly different at the conclusion of the study. The fear of mathematics was reduced for the experimental group at the end of the study, and their enjoyment of the subject matter was increased as a result of the intervention. No significant difference was reported concerning attitudes toward fear and enjoyment of learning mathematics for the control group. The researcher concluded that the use of InterAct Math tutorial software as part of the instructional delivery was beneficial and contributed to a positive attitude change. Other qualitative data obtained from the unstructured interviews of the treatment group supported these findings and reported that the change in attitudes was attributable to the use of the InterAct software in the instructional delivery of the course. The researcher concluded that the results of the study did not provide evidence that InterAct Math software could be credited with producing better learning outcomes. However, it appears that the InterAct Math tutorial software is an effective tutorial tool in promoting positive change in students' attitudes toward learning mathematics; thus, it is an effective tool for mathematics instruction. Based on the above results, it was concluded that the InterAct Math tutorial is an effective tutorial tool in promoting positive attitude change in students toward learning mathematics.

Mental Health in School-Aged Children Prenatally Exposed to Alcohol and Other Substances

PubMed Central

Sandtorv, Lisbeth Beate; Hysing, Mari; Rognlid, Malin; Nilsen, Sondre Aasen; Elgen, Irene Bircow

2017-01-01

Prenatal exposure to substances can possibly influence a child’s neurodevelopment and may impact on subsequent mental health. We investigated the mental health status of school-aged children referred to a pediatric hospital with a history of prenatal exposure to alcohol or other substances. Mental health was assessed using the Strengths and Difficulties Questionnaire and compared with a reference group. A total of 105 of 128 (82%) eligible children prenatally exposed to substances participated in the study, with 48 children exposed to alcohol and 57 to other substances. Strengths and Difficulties Questionnaire subscale mean scores, total difficulties scores, and total impact scores were statistically significantly higher in the group of exposed children, compared with the reference group. In this hospital-based population of school-aged children prenatally exposed to alcohol or other substances, the exposed group had an increased risk of mental health problems, compared with the reference group. PMID:29581703

Effects of combined radiofrequency radiation exposure on levels of reactive oxygen species in neuronal cells

PubMed Central

Kang, Kyoung Ah; Lee, Hyung Chul; Lee, Je-Jung; Hong, Mi-Na; Park, Myung-Jin; Lee, Yun-Sil; Choi, Hyung-Do; Kim, Nam; Ko, Young-Gyu; Lee, Jae-Seon

2014-01-01

The objective of this study was to investigate the effects of the combined RF radiation (837 MHz CDMA plus 1950 MHz WCDMA) signal on levels of intracellular reactive oxygen species (ROS) in neuronal cells. Exposure of the combined RF signal was conducted at specific absorption rate values of 2 W/kg of CDMA plus 2 W/kg of WCDMA for 2 h. Co-exposure to combined RF radiation with either H2O2 or menadione was also performed. The experimental exposure groups were incubator control, sham-exposed, combined RF radiation-exposed with or without either H2O2 or menadione groups. The intracellular ROS level was measured by flow cytometry using the fluorescent probe dichlorofluorescein diacetate. Intracellular ROS levels were not consistently affected by combined RF radiation exposure alone in a time-dependent manner in U87, PC12 or SH-SY5Y cells. In neuronal cells exposed to combined RF radiation with either H2O2 or menadione, intracellular ROS levels showed no statically significant alteration compared with exposure to menadione or H2O2 alone. These findings indicate that neither combined RF radiation alone nor combined RF radiation with menadione or H2O2 influences the intracellular ROS level in neuronal cells such as U87, PC12 or SH-SY5Y. PMID:24105709

Secretome of Differentiated PC12 Cells Enhances Neuronal Differentiation in Human Mesenchymal Stem Cells Via NGF-Like Mechanism.

PubMed

Srivastava, A; Singh, S; Pandey, A; Kumar, D; Rajpurohit, C S; Khanna, V K; Pant, A B

2018-03-12

The secretome-mediated responses over cellular physiology are well documented. Stem cells have been ruling the field of secretomics and its role in regenerative medicine since the past few years. However, the mechanistic aspects of secretome-mediated responses and the role of other cells in this area remain somewhat elusive. Here, we investigate the effects of secretome-enriched conditioned medium (CM) of neuronally differentiated PC12 cells on the neuronal differentiation of human mesenchymal stem cells (hMSCs). The exposure to CM at a ratio of 1:1 (CM: conditioned medium of PC12 cells) led to neuronal induction in hMSCs. This neuronal induction was compared with a parallel group of cells exposed to nerve growth factor (NGF). There was a marked increase in neurite length and expression of neuronal markers (β-III tubulin, neurofilament-M (NF-M), synaptophysin, NeuN in exposed hMSCs). Experimental group co-exposed to NGF and CM showed an additive response via MAPK signaling and directed the cells particularly towards cholinergic lineage. The ability of CM to enhance the neuronal properties of stem cells could aid in their rapid differentiation into neuronal subtypes in case of stem cell transplantation for neuronal injuries, thus broadening the scope of non-stem cell-based applications in the area of secretomics.

Effects of Tributyltin and Other Retinoid Receptor Agonists in Reproductive-Related Endpoints in the Zebrafish (Danio rerio).

PubMed

Lima, Daniela; Castro, L Filipe C; Coelho, Inês; Lacerda, Ricardo; Gesto, Manuel; Soares, Joana; André, Ana; Capela, Ricardo; Torres, Tiago; Carvalho, António Paulo; Santos, Miguel M

2015-01-01

Both field and experimental data examined the influence of exposure to environmental contaminant tributyltin (TBT) on marine organisms. Although most attention focused on the imposex phenomenon in gastropods, adverse effects were also observed in other taxonomic groups. It has been shown that imposex induction involves modulation of retinoid signaling in gastropods. Whether TBT influences similar pathways in fish is yet to be addressed. In this study, larvae of the model teleost Danio rerio were exposed to natural retinoids, all-trans-retinoic acid, 9-cis-retinoic acid, and all-trans-retinol, as well as to the RXR synthetic pan-agonist methoprene acid (MA) and to TBT. Larvae were exposed to TBT from 5 days post fertilization (dpf) to adulthood, and reproductive capacity was assessed and correlated with mode of action. TBT significantly decreased fecundity at environmentally relevant levels at 1 μg TBT Sn/g in diet. Interestingly, in contrast to previous reports, TBT altered zebrafish sex ratio toward females, whereas MA exposure biased sex toward males. Since fecundity was significantly altered in the TBT-exposed group with up to 62% decrease, the potentially affected pathways were investigated. Significant downregulation was observed in brain mRNA levels of aromatase b (CYP19a1b) in females and peroxisome proliferator activated receptor gamma (PPARg) in both males and females, suggesting an involvement of these pathways in reproductive impairment associated with TBT.

Long-term exposure to jet fuel: an investigation on occupationally exposed workers with special reference to the nervous system.

PubMed

Knave, B; Persson, H E; Goldberg, J M; Westerholm, P

1976-09-01

In the present study the results of a neurological and neurophysiological health examination of 29 aircraft factory workers chronically exposed to jet fuel vapors are presented. The exposed subjects were classified into a heavily exposed and a less heavily exposed group. The examination included a standardized clinical neurological examination, measurements of the conduction velocities in the peripheral nerves, and threshold determinations of vibratory sensations in the extremities. All 13 persons examined in the heavily exposed group and 7 of the 16 in the less heavily exposed group stated that they had repeatedly experienced acute effects (dizziness, respiratory tract symptoms, heart palpitations, a feeling of pressure on the chest, nausea, headache) of the jet fuel vapors in the inhaled air. A high rate of symptoms indicative of neurasthenia and psychasthenia and symptoms and signs indicative of polyneuropathy was observed both in the heavily exposed group and in the two groups combined in comparison with reference groups. Considering the presented facts concerning (a) the acute effects on repeated occasions, (b) the high rates of symptoms indicative of neurasthenia and psychasthenia and symptoms and signs indicative of polyneuropathy, and (c) the differences in the observations made between the two groups with varying degrees of exposure to jet fuel, the authors interpreted the results as indicative of a possible effect of long-term exposure to jet fuel on the nervous system.

Immunological pattern alteration in shoe, hide, and leather industry workers exposed to hexavalent chromium.

PubMed

Mignini, Fiorenzo; Tomassoni, Daniele; Traini, Enea; Vitali, Mario; Scuri, Stefania; Baldoni, Emilia; Grappasonni, Iolanda; Cocchioni, Mario

2009-12-01

The aim of this work was to assess the effects of hexavalent chromium [Cr(VI)] on shoe, leather, and hide industry workers, based on the assumption that Cr(VI) can behave as an environmental immunological "stressor." The immunological patterns of 84 male subjects were studied in relation to Cr(VI) hematic and urinary levels. Cr(VI) was measured through atomic absorption. Lymphocyte subsets, mitogen-mediated lymphocyte-proliferation, cytokine levels, and natural killer (NK) cytotoxic activity were also assayed. The urinary levels of the total amount of Cr(VI) were significantly higher in a subgroup of exposed subjects (group B) than in the control or in the lower exposed (group A). In group B, Cr(VI) caused a decrease in the density of glucocorticoid receptors (GR) on peripheral blood mononuclear cells (PBMC) and a increase of IL-6. Cr(VI) did not modify NK-mediated cytotoxicity, the plasmatic levels of inflammatory cytokines and related soluble receptors, and prostaglandin levels, while it tended to increase lymphocyte sensitivity to mitogens and the production of immunomodulant cytokines (IFN-gamma, IL-4, and IL-2). The experimental addition of Cr(VI) to the in vitro lymphocyte culture determined a significant inhibition of phagocytosis percentage, index, and killing percentage. These effects were neutralized by exogenous IFN-gamma. Cr(VI) could represent an environmental immunological stressor whose effects can be evaluated through laboratory surveys. The lymphocyte mitogen-induced proliferation, GR receptor on PBMC, and IL-6 plasma levels may represent a discriminating element between Cr(VI)-induced stress and other kinds of stress.

Association between sperm DNA integrity and seminal plasma antioxidant levels in health workers occupationally exposed to ionizing radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Dayanidhi; Salian, Sujith Raj; Kalthur, Guruprasad

There is a paucity of data regarding the association between occupational radiation exposure and risk to human fertility. Recently, we provided the first evidence on altered sperm functional characteristics, DNA damage and hypermethylation in radiation health workers. However, there is no report elucidating the association between seminal plasma antioxidants and sperm chromatin integrity in occupationally exposed subjects. Here, we assessed the seminal plasma antioxidants and lipid peroxidation level in 83 men who were occupationally exposed to ionizing radiation and then correlated with the sperm chromatin integrity. Flow cytometry based sperm chromatin integrity assay revealed a significant decline in αt valuemore » in the exposed group in comparison to the non-exposed group (P<0.0001). Similarly, both total and reduced glutathione levels and total antioxidant capacity in the seminal plasma were significantly higher in exposed group than the non-exposed group (P<0.01, 0.001 and 0.0001, respectively). However, superoxide dismutase level and malondialdehyde level, which is an indicator of lipid peroxidation in the seminal plasma, did not differ significantly between two groups. The total antioxidant capacity (TAC) and GSH level exhibited a positive correlation with sperm DNA integrity in exposed subjects. To conclude, this study distinctly shows that altered sperm chromatin integrity in radiation health workers is associated with increase in seminal plasma antioxidant level. Further, the increased seminal plasma GSH and TAC could be an adaptive measure to tackle the oxidative stress to protect genetic and functional sperm deformities in radiation health workers. - Highlights: • Seminal plasma antioxidants were measured in men occupationally exposed to radiation. • Sperm chromatin integrity was significantly affected in the exposed group. • Glutathione and total antioxidant capacity was significantly higher in exposed group. • Sperm DNA damage in exposed subjects affected seminal plasma antioxidant level.« less

Evaluation of the antioxidant effects of melatonin on the larynx mucosa of rats exposed to environmental tobacco smoke.

PubMed

Donmez, Z; Yigit, Ö; Bilici, S; Dursun, N; Gul, M; Dastan, S D; Uzun, H

2016-06-01

This study's aim was to investigate the effect of melatonin in terms of mitigating the effects of smoking on the laryngeal mucosa of rats exposed to environmental tobacco smoke. Rats were divided into four groups: Melatonin + Smoking group exposed to smoke with melatonin; Smoking group exposed to smoke without melatonin; Saline group not exposed to smoke without melatonin; Melatonin group not exposed to smoke with melatonin. CuZn-superoxide dismutase (CuZn-SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities were evaluated in plasma and tissues. Tissues were also examined the changes of squamous hyperplasia, keratosis, parakeratosis and epithelial hyperplasia by light microscope and the ultrastructural changes by electron microscope. Tissue SOD, CAT and GSH-Px activities were significantly higher in Saline and Melatonin groups than Melatonin + Smoking and Smoking groups. Plasma CuZn-SOD and CAT activities were significantly higher in Saline and Melatonin groups than Smoking group. Plasma GSH-Px showed no significant difference. The rate of epithelial hyperplasia was significantly higher in Smoking group than the other groups. The rate of parakeratosis was significantly higher in Smoking group than the other groups. The epithelial cells in Melatonin + Smoking group displayed, normal cell structure similar to those in Saline group under electron microscope. The study shows that smoking induces substantial pathological changes in the laryngeal mucosa and melatonin may have some beneficial effects in partially reversing smoking-induced laryngeal injury by inducing the expression of antioxidants; biochemical and histological outcomes also support these findings due to preventing tissue damage in laryngeal mucosa exposed to smoke. © 2015 John Wiley & Sons Ltd.

Significant accumulation of persistent organic pollutants and dysregulation in multiple DNA damage repair pathways in the electronic-waste-exposed populations.

PubMed

He, Xiaobo; Jing, Yaqing; Wang, Jianhai; Li, Keqiu; Yang, Qiaoyun; Zhao, Yuxia; Li, Ran; Ge, Jie; Qiu, Xinghua; Li, Guang

2015-02-01

Electronic waste (e-waste) has created a worldwide environmental and health problem, by generating a diverse group of hazardous compounds such as persistent organic pollutants (POPs). Our previous studies demonstrated that populations from e-waste exposed region have a significantly higher level of chromosomal aberrancy and incidence of DNA damage. In this study, we further demonstrated that various POPs persisted at a significantly higher concentration in the exposed group than those in the unexposed group. The level of reactive oxygen species and micronucleus rate were also significantly elevated in the exposed group. RNA sequencing analysis revealed 31 genes in DNA damage responses and repair pathways that were differentially expressed between the two groups (Log2 ratio >1 or <-1). Our data demonstrated that both females and males of the exposed group have activated a series of DNA damage response genes; however many important DNA repair pathways have been dysregulated. Expressions of NEIL1/3 and RPA3, which are critical in initiating base pair and nucleotide excision repairs respectively, have been downregulated in both females and males of the exposed group. In contrast, expression of RNF8, an E3 ligase involved in an error prone non-homologous end joining repair for DNA double strand break, was upregulated in both genders of the exposed group. The other genes appeared to be differentially expressed only when the males or females of the two groups were compared respectively. Importantly, the expression of cell cycle regulatory gene CDC25A that has been implicated in multiple kinds of malignant transformation was significantly upregulated among the exposed males while downregulated among the exposed females. In conclusion, our studies have demonstrated significant correlations between e-waste disposing and POPs accumulation, DNA lesions and dysregulation of multiple DNA damage repair mechanisms in the residents of the e-waste exposed region. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of ultraviolet irradiation on the bond strength of a composite resin adhered to stainless steel crowns.

PubMed

Baeza-Robleto, Selene J; Villa-Negrete, Dulce M; García-Contreras, René; Scougall-Vílchis, Rogelio J; Guadarrama-Quiroz, Luis J; Robles-Bermeo, Norma L

2013-01-01

A technique whereby the practitioner could improve the esthetic appearance of anterior stainless steel crowns (SSC) could provide a cost-effective alternative to more expensive commercially available preveneered SSCs, which may not be uniformly available. The purpose of this study was to evaluate the effects of ultraviolet (UV) irradiation of the metal crown surface on the shear bond strength of composite resin adhered to stainless steel crowns. Seventy extracted anterior bovine teeth randomly divided into 2 groups (n=35/group), were restored with primary maxillary left central incisor SSCs. Surface roughening with a green stone was performed on the labial surfaces, and the crowns of the experimental group were exposed to UV irradiation for 80 minutes. All samples were treated with metal-composite adhesive, followed by composite opaquer. Standardized composite blocks were bonded on the treated surfaces, and the shear bond strength was tested at 1 mm/minute. The values were recorded in MPa and statistically analyzed. The mean value of shear bond strength was significantly higher for the experimental group (19.7 ± 4.3 MPa) than the control group (16.3 ± 4.5 MPa). Ultraviolet irradiation of primary tooth stainless steel crowns significantly increased the shear bond strength of composite resin adhered to the facial surface.

Preliminary studies on haematological and plasmatic parameters in gilthead sea bream (Sparus aurata) held under day/night temperature variations.

PubMed

Matias, Ana C; Ribeiro, Laura; Araujo, Ravi L; Pousão-Ferreira, Pedro

2018-02-01

This study aimed to evaluate to what extent diel water temperature oscillations over a short period of time (41 h) affected haematologic and plasmatic parameters of gilthead sea bream. Sea bream juveniles (160 fish; 177.2 ± 20.9 g) were divided in two homogenous groups, experimental and control. The experimental group was exposed to water at 22.3 ± 0.6 °C between 5 a.m. and 5 p.m. and to colder water from 5 p.m. to 5 a.m. (temperature variation of 8.6 ± 0.3 °C) during 41h period, whereas for the control group, water temperature was maintained constant (22.4 ± 0.7 °C) for the same period. Fish were fed three times per day (10:30 a.m., 2 p.m., 4 p.m.). Blood was collected from fish caudal veins (n = 6) at different time points (10 a.m., 1 p.m., 5 p.m., 6:30 p.m., 8 p.m. and 10 a.m. of the following day) from each group, for haematologic (haematocrit and haemoglobin) and plasmatic (glucose, cortisol, triglycerides and total protein) determinations. All parameters studied tended to vary throughout the study period, both for experimental and control groups. Significant differences were observed between the two groups for all the studied parameters at different sampling points. These differences were observed near the influence of the cold-water period or during the cooling-water period. Results suggested that colder water temperature cycles depressed fish metabolic activity and affected the levels of the analysed blood-circulating metabolites. Overall, results suggested that stress response was similar for experimental and control groups and that gilthead sea bream were able to cope with diel water temperature variations.

Reappraisal writing relieves social anxiety and may be accompanied by changes in frontal alpha asymmetry

PubMed Central

Wang, Fen; Wang, Changming; Yin, Qin; Wang, Kui; Li, Dongdong; Mao, Mengchai; Zhu, Chaozhe; Huang, Yuxia

2015-01-01

It is widely reported that expressive writing can improve mental and physical health. However, to date, the neural correlates of expressive writing have not been reported. The current study examined the neural electrical correlates of expressive writing in a reappraisal approach. Three groups of participants were required to give a public speech. Before speaking, the reappraisal writing group was asked to write about the current stressful task in a reappraisal manner. The irrelevant writing group was asked to write about their weekly plan, and the non-writing group did not write anything. It was found that following the experimental writing manipulation, both reappraisal and irrelevant writing conditions decreased self-reported anxiety levels. But when re-exposed to the stressful situation, participants in the irrelevant writing group showed increased anxiety levels, while anxiety levels remained lower in the reappraisal group. During the experimental writing manipulation period, participants in the reappraisal group had lower frontal alpha asymmetry scores than those in the irrelevant writing group. However, following re-exposure to stress, participants in the reappraisal group showed higher frontal alpha asymmetry scores than those in the irrelevant writing group. Self-reported anxiety and frontal alpha asymmetry of the non-writing condition did not change significantly across these different stages. It is noteworthy that expressive writing in a reappraisal style seems not to be a fast-acting treatment but may instead take effect in the long run. PMID:26539146

Effect of dietary supplementation of vitamin C on growth, reactive oxygen species, and antioxidant enzyme activity of Apostichopus japonicus (Selenka) juveniles exposed to nitrite

NASA Astrophysics Data System (ADS)

Luo, Zuoyong; Wang, Baojie; Liu, Mei; Jiang, Keyong; Liu, Mingxing; Wang, Lei

2014-07-01

Different amounts of vitamin C were added to diets fed to juveniles (2.5 ± 0.15 g) of sea cucumber Apostichopus japonic u s (Selenka) in an attempt to reduce the stress response of specimens exposed to nitrite stress. A commercial feed was used as the control diet and three experimental diets were made by supplementing 1 000, 1 500, or 2 000 mg vitamin C/kg diet to control diet separately in a 45-day experiment. Sea cucumbers were exposed to three different levels (0.5, 1.0, and 1.5 mg/L) of nitrite stress for 4, 8, and 12 h at four time intervals (0, 15, 30, and 45 d). Growth of the animals was recorded during the experiment. Reactive oxygen species (ROS) (i.e. hydroxyl free radical (-OH), malondialdehyde (MDA) and total antioxidant capacity (T-AOC)) and antioxidant enzyme activities (i.e., superoxide dismutase (SOD) and catalase (CAT)) were measured. Response surface methodology (RSM) was used to analyze the effect of multiple factors on ROS indices and enzyme activities. Weight gain (WG) and special growth rate (SGR) of vitamin C supplementation groups were significantly higher than those of control group ( P < 0.05). The levels of -OH and MDA increased under exposure time extending and nitrite concentration increasing, whereas T-AOC level decreased. SOD and CAT activities increased at 4 h and 8 h and decreased at 12 h. During the days in which the animal consumed experimental diets, the levels of -OH and MDA decreased and that of T-AOC increased. This result suggests that diets containing vitamin C could reduce the nitrite stress response in the animals and increase their antioxidant capacity. The multifactor regression equation of growth performance, ROS indices, and duration of feeding results suggest that vitamin C supplementation of 1 400-2 000 mg/kg diet for 29-35 days could reduce effectively the effects of nitrite exposure.

Color vision impairments among shipyard workers exposed to mixed organic solvents, especially xylene.

PubMed

Lee, Eun-Hee; Paek, Domyung; Kho, Young Lim; Choi, Kyungho; Chae, Hong Jae

2013-01-01

We evaluated color vision impairment in workers exposed to organic solvents, especially xylene. Three groups of subjects, comprising 63 workers occupationally exposed to organic solvents, 122 non-exposed workers in the same industry, and 185 subjects from the general population as controls, were evaluated for color vision. Exposure to solvents was indirectly evaluated by measuring the concentration of a urinary metabolite. Color vision was assessed using the Lanthony Desaturated 15-hue (Lanthony D-15) panel. Color confusion index (CCI) values in the exposed group were significantly higher than in the non-exposed workers or the general population, after adjustment for age and education, and significantly correlated with the concentration of methylhippuric acid. Color vision impairments were detected more frequently among the exposed group, and the most common types were type III and complex impairments. The rate of type III impairments was 9.52% in the exposed group, 1.64% in the non-exposed group, and 1.62% in the general population. Our results support the hypothesis that acquired color vision impairments could be induced by exposure to xylene. Testing for color vision impairment is a relatively simple, non-invasive and sensitive diagnostic method for relatively low-level exposures to xylene. Copyright © 2013 Elsevier Inc. All rights reserved.

Online Evaluative Conditioning Did Not Alter Internalized Homonegativity or Self-Esteem in Gay Men.

PubMed

Fleming, John B; Burns, Michelle Nicole

2017-09-01

Internalized homonegativity is linked to psychological distress in sexual minorities and is thus a potential treatment target in this population. Previous studies have shown that evaluative conditioning (EC) can modify self-esteem, another self-directed attitude. The present study aimed to determine if EC deployed over the Internet could modify self-esteem and internalized homonegativity. Gay men recruited online (N = 184) were randomly assigned to a control group or an experimental condition. Participants completed self-reports and measures of implicit attitudes before and after being exposed to control or experimental tasks. The study was administered online. There were no significant between-group differences on implicit or explicit self-esteem (ps > .49) or internalized homonegativity (ps > .28). Despite past laboratory success, Internet-based EC did not produce significant effects in implicit or explicit self-directed attitudes. Post hoc analyses did not support any of several potential explanations for these results. Alternative explanations are discussed. © 2016 Wiley Periodicals, Inc.

[Study on effects of bioelectric parameters of rats in electromagnetic radiation of HV transmission line].

PubMed

Zhang, Anying; Pang, Xiaofeng; Yuan, Ping

2007-02-01

With the development of economy and coming of information era, the chance of exposure to electromagnetic fields with various frequencies has been increased for every human. The effects of electromagnetic radiattion on human being's health are versatile. To study the effects of bioelctronic parameters of rats in the electromagnetic radiations of HV transmission line, EEG, ECG and CMAP were measured in rats exposed to simulating high-voltage transmission line electromagnetic radiation for over one year. Brain tissues were studied by Fourier transform infrared spectroscopy. The results showed that no significant difference between exposed group and control group in EEG; however the FT-infrared spectra of brain tissues were different; the ECG of the exposed animals was considerably altered. Significant slowing of heart rate was observed in those rates exposed to EMFs; the latent period of CMAP in exposed group were not different compared with those of control group however there was a significant difference in wave amplitude of CMAP between the exposed group and control group. All results indicated that there must be some effects on bioelectric parameters of rats exposed to electromagnetic radiation of high-voltage transmission line for a long time.

The Efficacy of Internet-based Cognitive Behavioral Therapy on the Anxiety Disorders among Adolescent Girls.

PubMed

Karbasi, Afsaneh; Haratian, Azadeh

2018-01-01

The prevalence of anxiety disorders among children and adolescents are found to be approximately between 8-12 and 5-10, respectively, and the long-lasting effects of such disorders can expose the sufferers to impairment and dysfunction in several areas of life the examples of which are poor educational performance, low self-esteem, and depression. The present study aims to evaluate the efficacy of internet-based, cognitive-behavioral therapy (ICBT) in treating the anxiety disorders among adolescent females. The sample included thirty girls aged between 10 and 18 years suffering from a variety of anxiety disorders, under pharmaceutical therapy and referred to clinics of child and adolescent psychiatry specialists in Isfahan. The sample was selected through diagnostic interviews by psychiatrists based on the Diagnostic and Statistical Manual of Mental Disorders, 4 th Edition, Text Revision; afterward, they were randomly assigned to either the experimental or the control groups. To evaluate the efficacy of an ICBT in reducing anxiety disorder symptoms, Screen for Child Anxiety Related Emotional Disorders questionnaire was administered among the patients both before and 4 weeks after the treatment. The covariance analysis results aimed to compare the anxiety disorder score variations between the two groups which demonstrate the fact that anxiety disorder scores in these two groups differ from one another ( P < 0.001). This study is comprised of two Conclusions.the significant reduction in the mean of anxiety disorders scores in the experimental group compared to those in control group can be indicative of the efficacy of ICBT. In addition the significant reduction in the average of anxiety disorders symptoms' scores according to the type of anxiety disorders in the experimental group, compared to those in control group, can be indicative of the efficacy of ICBT.

The Effect of Educational Intervention Based on Health Belief Model and Social Support on Promoting Skin Cancer Preventive Behaviors in a Sample of Iranian Farmers.

PubMed

Jeihooni, Ali Khani; Rakhshani, Tayebeh

2018-01-08

Skin cancer is one of the most common cancers in Iran. Farmers are exposed to the sun's ultraviolet radiation due to their job and are susceptible to skin cancer. The aim of this study is to survey the effect of educational intervention based on health belief model and social support on promoting skin cancer preventive behaviors in farmers of Fasa City, Fars province, Iran. In this quasi-experimental study, 200 farmers (100 in experimental group and 100 in control group) in Fasa City, Fars, Iran, were selected in 2017. The educational intervention for the experimental group consisted of eight training sessions (introduction to skin cancer, risk factors, complications, benefits and barriers to proper use of sunscreen, UV sunglasses and physical protection, self-efficacy in applying preventive behaviors, role of social support). A questionnaire consisting of demographic information, knowledge, HBM constructs (perceived susceptibility, severity, benefits, barriers, self-efficacy and cues to action), and social support was used to measure skin cancer preventive behaviors before, 3 months after the intervention, and 6 months later. Data were analyzed using SPSS-22 via chi-squared, independent samples t test, Mann-Whitney, and repeated measures ANOVA at a significance level of 0.5. The mean age of the farmers was 42.21 ± 10.52 years in the experimental group and 44.28 ± 10.16 years in the control group. Three months after the intervention and 6 months after the intervention, the experimental group showed a significant increase in the knowledge, perceived susceptibility, perceived severity, perceived benefits, self-efficacy, cues to action, social support, and skin cancer preventive behaviors compared to the control group. This study showed the effectiveness of the intervention based on the HBM constructs and social support in adoption of skin cancer preventive behaviors in 3 and 6 months post intervention in farmers. Hence, these models can act as a framework for designing and implementing educational interventions for the prevention of skin cancer.

Lifetime exposure to low doses of lead in rats: effect on selected parameters of carbohydrate metabolism.

PubMed

Nováková, Jaroslava; Lukačínová, Agnesa; Lovásová, Eva; Cimboláková, Iveta; Rácz, Oliver; Ništiar, František

2015-05-01

The aim of the study was to assess the effects of exposure to low doses of lead dissolved in drinking water (average daily dose of 2.2 mg kg(-1) day(-1)) on selected carbohydrate metabolism parameters in 20 wistar rats. Animals were divided into two groups - control (C) (group drinking clear water) and experimental group (Pb; group exposed to low doses of lead acetate in a concentration of 100 μmol l(-1) of drinking water). In this study, we studied the biochemical parameters (glucose, haemoglobin (Hb), glycated haemoglobin (HbA1c), lactate dehydrogenase (LDH) and amylase (AMS)) in rat blood. Glucose and Hb concentration and AMS activity decreased, LDH activity increased but HbA1c concentration levels did not change in rats exposed to lead. Our results well documented that lifetime exposure to lead affected carbohydrate metabolism of rats. Some parameters like concentration of Hb as well as activities of AMS and LDH are useful markers of intoxication of rats with lead. For the evaluation of results (e.g. AMS), not only the data at the end of the experiment should be taken into account but also the entire duration of trials (i.e. more time steps) that makes results more objective should be considered. © The Author(s) 2013.

Histological investigations on thymus of male rats prenatally exposed to bisphenol A.

PubMed

Aydemir, Işıl; Kum, Şadiye; Tuğlu, Mehmet İbrahim

2018-09-01

Bisphenol A is called as a endocrine-distrupting chemical because of the its steroid-like activity and it used in the construction of plastic containing materials. It is indicated that bisphenol A can pass the human serum, urine, follicular fluid, placenta and umblical cord as a result of the use of substances containing this agent. In this study, we aimed to investigate the effects of bisphenol A on the development of the thymus, a primary lymphoid organ which plays an important role in the specific immunity. The adult pregnant female rats were administered orally with bisphenol A (for 21 days) and postnatal thymus samples were obtained on day 21, 45 and 90 and were performed for histochemical and immunohistochemical staining for CD3, CD4, CD8 and CD79a and TUNEL assay for the apoptotic cells. Evaluation of all groups, CD3, CD4, CD8 and CD79a stainings were decreased in the experimental groups compared with control group. The apoptotic cells were determined in the all groups on day 90 as a result of the thymus involution. It is noted that there was not any histological and morphological damages in the rats prenatally exposed the bisphenol A. The effect of the bisphenol A is unknown in the future, but there is no problem in the adult rats. Copyright © 2018 Elsevier Ltd. All rights reserved.

Occupational exposure to poultry and prevalence of antibodies against Marek's disease virus and avian leukosis retroviruses.

PubMed Central

Choudat, D; Dambrine, G; Delemotte, B; Coudert, F

1996-01-01

OBJECTIVES: To compare the prevalence of antibodies against Marek's disease herpes virus (MDV) and against avian leukosis viruses type C (ALV) in groups of workers exposed to poultry and in unexposed groups. METHODS: Antibodies directed against avian viral proteins were detected by enzyme linked immunosorbent assay in 549 subjects. Exposure to chickens was high in two subgroups: farmers on intensive chicken farms and workers at chicken slaughterhouses. One subgroup, traditional farmers on dairy or pig farms with poultry, had moderate exposure to poultry. Another subgroup, farmers and slaughterhouse workers on quail farms, had high exposure to quails. Three subgroups were not exposed to chickens: farmers on dairy or pig farms without poultry, workers at cattle slaughterhouses, and white collar workers. Also, MDV antibodies were tested after serum sample adsorption with chicken antigens in 134 serum samples. RESULTS: The prevalence of antibodies against MDV was significantly higher in the exposed subgroups than in unexposed groups (odds ratio (OR) 6.17; 95% confidence interval (95% CI) 3.91-9.75). No association was found between seroprevalence and age. However, higher prevalence was found among women and was related to duration of exposure to chickens. The concentration of antibodies from a few subjects remained very high after adsorption. Significant differences between the men and women were found for the prevalence of antibodies for ALV but were not related to exposure to chickens. CONCLUSIONS: The prevalence of antibodies against MDV was significantly higher among workers exposed to chickens and was related to sex and duration of exposure. The higher prevalence of antibodies against avian oncogenic viruses found among women compared with men may be induced by differences in exposure or by genetic factors. The meaning of these high titres could be related to the presence of MDV in humans. Because the involvement of animal oncogenic viruses in human cancer is indicated by epidemiological and some experimental studies, the integration of viral DNA in human cells needs to be investigated. PMID:8758036

The effects of food advertising and cognitive load on food choices

PubMed Central

2014-01-01

Background Advertising has been implicated in the declining quality of the American diet, but much of the research has been conducted with children rather than adults. This study tested the effects of televised food advertising on adult food choice. Methods Participants (N = 351) were randomized into one of 4 experimental conditions: exposure to food advertising vs. exposure to non-food advertising, and within each of these groups, exposure to a task that was either cognitively demanding or not cognitively demanding. The number of unhealthy snacks chosen was subsequently measured, along with total calories of the snacks chosen. Results Those exposed to food advertising chose 28% more unhealthy snacks than those exposed to non-food-advertising (95% CI: 7% - 53%), with a total caloric value that was 65 kcal higher (95% CI: 10-121). The effect of advertising was not significant among those assigned to the low-cognitive-load group, but was large and significant among those assigned to the high-cognitive-load group: 43% more unhealthy snacks (95% CI: 11% - 85%) and 94 more total calories (95% CI: 19-169). Conclusions Televised food advertising has strong effects on individual food choice, and these effects are magnified when individuals are cognitively occupied by other tasks. PMID:24721289

Flow-cytometric determination of genotoxic effects of exposure to petroleum in mink and sea otters

USGS Publications Warehouse

Bickham, J.W.; Mazet, J.A.; Blake, J.; Smolen, M.J.; Lou, Y.; Ballachey, Brenda E.

1998-01-01

Three experiments were conducted to investigate the genotoxic effects of crude oil on mink and sea otters, In the first experiment, the effects on mink of chronic exposure to weathered Prudhoe Bay crude oil were studied, Female mink were fed a diet that included weathered crude oil for a period of 3 weeks prior to mating, during pregnancy and until weaning. Kits were exposed through lactation and by diet after weaning until 4 months of age. Kidney and liver tissues of the kits were examined using flow cytometry (FCM) and it was found that the genome size was increased in kidney samples from the experimental group compared to the control group. This effect was probably due to some type of DNA amplification and it could have been inherited from the exposed mothers or have been a somatic response to oil exposure in the pups, No evidence of clastogenic effects, as measured by the coefficient of variation (CV) of the G(1) peak, was found in kidney or liver tissue. In the second experiment, yearling female mink were exposed either by diet or externally to crude oil or bunker C fuel oil. Evidence for clastogenic damage was found in spleen tissue for the exposure groups, but not in kidney tissue. No evidence of increased genome size was observed. In the third experiment, blood was obtained from wild-caught sea otters in Prince William Sound. The sea otters represented two populations: one from western Prince William Sound that was potentially exposed to oil from the Exxon Valdez oil spill and a reference population from eastern Prince William Sound that did not receive oil from the spill. The spill had occurred 1.5 years prior to obtaining the blood samples. Although the mean CVs did not differ between the populations, the exposed population had a significantly higher variance of CV measurements and five out of 15 animals from the exposed population had CVs higher than the 95% confidence limits of the reference population, It is concluded that FCM is a sensitive indicator of the clastogenic effects of oil exposure and that haematopoietic tissues and blood are best for detecting clastogenic damage. Moreover, the observed differences in the genome size of the kidney cells mere possibly heritable effects, but this needs further investigation. Lastly, sea otters exposed to spilled oil 1.5 years earlier showed evidence of clastogenic damage in one-third of the individuals sampled.

Nutritional Status among the Children of Age Group 5-14 Years in Selected Arsenic Exposed and Non-Exposed Areas of Bangladesh.

PubMed

Rezaul Karim, Mohammad; Ahmad, Sk Akhtar

2014-12-01

To assess and compare the nutritional status of children aged 5-14 years in arsenic exposed and non- exposed areas. It was a cross sectional study conducted on 600 children of age 5-14 years from arsenic exposed and non-exposed areas in Bangladesh. Designed questionnaire and check list were used for collection of data. To estimate BMI necessary anthropometric measurements of the studied children were done. Dietary intakes of the study children were assessed using 24-hours recall method. The difference of socio-economic conditions between the children of exposed area and non-exposed area was not significant. On an average the body mass index was found to be significantly (p < 0.01) lower among the children of arsenic exposed area (49%) in comparison to that of children in non-exposed area (38%). Stunting (p < 0.01), wasting (p < 0.05) and underweight (p < 0.05) were significantly higher in exposed group in comparison to non-exposed group. No significant difference of nutrition intake was found between exposed and non-exposed children as well as thin and normal children. In this study children exposed to arsenic contaminated water were found to be suffered from lower nutritional status.

Induction of nasal and nasopharyngeal tumours in Sprague-Dawley rats fed with Chinese salted fish.

PubMed

Zheng, X; Luo, Y; Christensson, B; Drettner, B

1994-01-01

Epidemiological studies have implied that Chinese salted fish is a human nasopharyngeal carcinogen. In the present study, 162 Sprague-Dawley rats were randomly assigned to one of four experimental groups. Rats in groups 1 (n = 41) and 3 (n = 40) were exposed to salted fish from birth through the breast feeding period by giving the maternal rats a diet containing 10% and 5% salted fish, respectively, later feeding the rats with pellets containing 10% and 5% of salted fish respectively. In group 2, the rats (n = 41) were given pellets containing 10% of salted fish from 6 weeks of age. Rats in group 4 (n = 40), serving as controls, were only given ordinary pellets. Three rats had nasopharyngeal tumours, 2 from group 1 had a poorly differentiated carcinoma and a squamous cell carcinoma. One rat from group 2 had a squamous cell carcinoma. Four rats had nasal tumours, one fibrosarcoma and one adenocarcinoma were found in rats from group 1. One rhabdomyosarcoma was found in group 2, and one soft tissue sarcoma was found in a rat in group 3. No nasal or nasopharyngeal tumours appeared in the control group. The difference in the occurrence of malignant nasal and nasopharyngeal tumours among the four experimental groups was statistically significant (one tailed p for trend = 0.041). The frequency of tumours appearing in other organs such as the breast, kidney, lung, liver and brain was not significantly different between the salted fish treated groups and the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway remodeling associated with cough hypersensitivity as a consequence of persistent cough: An experimental study.

PubMed

Nakaji, Hitoshi; Niimi, Akio; Matsuoka, Hirofumi; Iwata, Toshiyuki; Cui, Shilei; Matsumoto, Hisako; Ito, Isao; Oguma, Tsuyoshi; Otsuka, Kojiro; Takeda, Tomoshi; Inoue, Hideki; Tajiri, Tomoko; Nagasaki, Tadao; Kanemitsu, Yoshihiro; Chin, Kazuo; Mishima, Michiaki

2016-11-01

Chronic cough involves airway remodeling associated with cough reflex hypersensitivity. Whether cough itself induces these features remains unknown. Guinea pigs were assigned to receive treatment with citric acid (CA), saline (SA), or CA+dextromethorphan (DEX). All animals were exposed to 0.5M CA on days 1 and 22. On days 4-20, the CA and CA+DEX groups were exposed to CA, and the SA group to saline thrice weekly, during which the CA+DEX group was administered DEX pretreatment to inhibit cough. The number of coughs was counted during each 10-min CA or SA exposure. Terbutaline premedication was started to prevent bronchoconstriction. Bronchoalveolar lavage and pathology were examined on day 25. Average cough number for 10 CA exposures was examined as "cough index" in the CA group, which was divided into frequent (cough index>5) and infrequent (<5) cough subgroups for lavage and pathology analysis. The number of coughs significantly increased in the CA group from day 13 onwards. In the CA+DEX and SA groups, the number of coughs did not differ between days 1 and 22, while average number of coughs during days 4-20 was significantly lower than at days 1 and 22. Bronchoalveolar cell profiles were similar among the four groups. The smooth muscle area of small airways was significantly greater in the frequent-cough subgroup than in the other groups (in which it was similar), and highly correlated with cough index in CA group. Repeated cough induces airway smooth muscle remodeling associated with cough reflex hypersensitivity. Copyright © 2016 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.

Characteristic miR-24 Expression in Gastric Cancers among Atomic Bomb Survivors.

PubMed

Naito, Yutaka; Oue, Naohide; Pham, Trang T B; Yamamoto, Manabu; Fujihara, Megumu; Ishida, Teruyoshi; Mukai, Shoichiro; Sentani, Kazuhiro; Sakamoto, Naoya; Hida, Eisuke; Sasaki, Hiroki; Yasui, Wataru

2015-01-01

To elucidate the mechanism of radiation-induced cancers, we analyzed the expression profiles of microRNAs extracted from formalin-fixed paraffin-embedded (FFPE) gastric cancer (GC) tissue samples from atomic bomb survivors. The expression levels of miR-21, miR-24, miR-34a, miR-106a, miR-143, and miR-145 were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The expression of microRNAs was measured by qRT-PCR in a Hiroshima University Hospital cohort comprising 32 patients in the high-dose-exposed group and 18 patients in the low-dose-exposed group who developed GC after the bombing. The GC cases showing high expression of miR-24, miR-143, and miR-145 were more frequently found in the high-dose-exposed group than in the low-dose-exposed group. We next performed qRT-PCR of miR-24, miR-143, and miR-145 in a cohort from the Hiroshima Red Cross Hospital and Atomic-Bomb Survivors Hospital comprising 122 patients in the high-dose-exposed group and 48 patients in the low-dose-exposed group who developed GC after the bombing. High expressions of miR-24 and miR-143 were more frequently found in the high-dose-exposed group than in the low-dose-exposed group. Multivariate analysis demonstrated that only high expression of miR-24 was an independent predictor for the exposure status. These results suggest that the measurement of miR-24 expression from FFPE samples is useful to identify radiation-associated GC.

[Effects of simulated hypoxia on dielectric properties of mouse erythrocytes].

PubMed

Ma, Qing; Tang, Zhi-Yuan; Wang, Qin-Wen; Zhao, Xin

2008-02-01

To explore the influence of simulated altitude hypoxia on dielectric properties of mouse erythrocytes. Experimental animals were divided into the plain control group(control) and simulated altitude hypoxia group (altitude). The AC impedance of mouse erythrocytes was measured with the Agilent 4294A impedance analyzer, the influence of simulated altitude hypoxia on dielectric properties of mouse erythrocytes was observed by cell dielectric spectroscopy, Cole-Cole plots, loss factor spectrum, loss tangent spectrum, and curve fitting analysis of Cole-Cole equation. After mice were exposed to hypoxia at simulated 5000 m altitude for 4 weeks, permittivity at low frequency (epsilonl) and dielectric increment (deltaepsilon) increased 57% and 59% than that of control group respectively, conductivity at low frequency (kappal) and conductivity at high frequency (kappah) reduced 49% and 11% than that of control group respectively. The simulated altitude hypoxia could arise to increase dielectric capability and depress conductive performance on mouse erythrocytes.

Artistic creation as stimulated by superimposed versus combined-composite visual images.

PubMed

Rothenberg, A

1986-02-01

The creative role of homospatial thinking in visual art was assessed in an experiment with 39 highly talented young artists. In order to compare the creative effects of visual elements occupying the same space with identical elements arrayed in a combined foreground and background organization, superimposed slide images were presented to a randomly selected portion of the subject group, and the other portion of the subject group viewed the same slide images constructed into a figure-ground composite. Both groups produced three drawings stimulated by the slide stimuli, and these drawings were independently judged by three art experts. Results were that drawings produced by the group exposed to the superimposed images were rated higher in creative potential than those stimulated by the figure-ground controls. These results extend previous experimental findings of a tendency toward homospatial thinking in creative individuals in literature and visual art.

[Effect of lead-exposed astrocytes on neuronal synaptic formation].

PubMed

Cui, Yan; Li, Tingting; Yu, Haiyang; Liao, Yingjun; Jin, Yaping

2014-09-01

To investigate the effect of lead-exposed astrocyte conditioned medium (ACM) on the synaptic formation of neurons and to provide reference for the mechanism of lead neurotoxicity. Astrocytes were cultured in the medium containing 50, 100, 200, 400, and 800 µmol/L lead acetate for 72 h. Alamar Blue was used to assess the cell viability of astrocytes, and then ACM was collected. Primarily cultured neurons were divided into six groups: pure culture group, non-glutamic acid (Glu)-induced ACM treatment group, Glu-induced lead-free ACM treatment group, and Glu-induced 50, 100, and 200 µmol/L lead acetate-exposed ACM treatment groups. Neurons were collected after being cultured in ACM for 24, 48, or 72 h. The content of synaptophysin (SYP) in neurons was determined by Western blot. The SYP expression in neurons was measured by immunofluorescence after being cultured in ACMfor 72 h. In all lead-exposed groups, the cell viability of astrocytes declined with increasing concentration of lead (P < 0.05). The Western blot showed that compared with the pure culture group, the non-Glu-induced ACM treatment group and Glu-induced lead- free ACM treatment group had significantly increased content of SYP in neurons (P < 0.01); compared with the non-Glu-induced ACM treatment group, the Glu-induced ACM treatment groups had significantly reduced SYP expression in neurons (P < 0.05); compared with the Glu-induced lead-free ACM treatment group, all lead-exposed ACM treatment groups had the content of SYP in neurons significantly reduced with increasing concentration of lead after 72-h culture (P < 0.01), the 200 µmol/L lead-exposed ACM treatment group had significantly reduced content of SYP in neurons after 48-h culture (P < 0.01), and all lead-exposed ACM treatment groups showed no significant changes in the content of SYP in neurons after 24-h culture. Double-labeling immunofluorescence of SYP showed that all lead-exposed ACM treatment groups had a significant decrease in the number of SYP-fluorescent particles after 72-h culture (P < 0.05). Astrocytes promote synaptic formation of neurons, which may be inhibited during lead exposure.

Post epidemic giardiasis and gastrointestinal symptoms among preschool children in Bergen, Norway. A cross-sectional study

PubMed Central

2010-01-01

Background A surprisingly low number of children became ill with giardiasis during the large waterborne outbreak of Giardia lamblia in Bergen, Norway during autumn 2004. The aim of the present study was to evaluate the prevalence of giardiasis among exposed children one year after an outbreak and compare faecal carriage of Giardia and abdominal symptoms among exposed versus unexposed children one year after the epidemic. Methods Children between 1 and 6 years old were recruited from the local health care centres in Bergen municipality in the period between June 2005 and January 2006. One faecal sample per child was collected and examined for presence of Giardia with a rapid immunoassay antigen test, and parents were asked to answer a questionnaire. A total of 513 children participated, 378 in the group exposed to contaminated water, and 135 in the in the group not exposed. Results In the exposed group eleven children had been treated for giardiasis during the epidemic and none in the unexposed group. Giardia positive faecal tests were found in six children, all in the exposed group, but the difference between the groups did not reach statistical significance. All six Giardia positive children were asymptomatic. No differences were found between the groups regarding demographic data, nausea, vomiting, different odour from stools and eructation. However, the reported scores of abdominal symptoms (diarrhoea, bloating and stomach ache) during the last year were higher in the exposed group than in the unexposed group. Conclusions A low prevalence of asymptomatic Giardia infection (1.7%) was found among exposed children around one year after the epidemic (1.2% overall prevalence in the study). In the present setting, pre-school children were therefore unlikely to be an important reservoir for continued transmission in the general population. PMID:20346102

Lysosomal responses to heat-shock of seasonal temperature extremes in Cd-exposed mussels.

PubMed

Múgica, M; Izagirre, U; Marigómez, I

2015-07-01

The present study was aimed at determining the effect of temperature extremes on lysosomal biomarkers in mussels exposed to a model toxic pollutant (Cd) at different seasons. For this purpose, temperature was elevated 10°C (from 12°C to 22°C in winter and from 18°C to 28°C in summer) for a period of 6h (heat-shock) in control and Cd-exposed mussels, and then returned back to initial one. Lysosomal membrane stability and lysosomal structural changes in digestive gland were investigated. In winter, heat-shock reduced the labilisation period (LP) of the lysosomal membrane, especially in Cd-exposed mussels, and provoked transient lysosomal enlargement. LP values recovered after the heat-shock cessation but lysosomal enlargement prevailed in both experimental groups. In summer, heat-shock induced remarkable reduction in LP and lysosomal enlargement (more markedly in Cd-exposed mussels), which recovered within 3 days. Besides, whilst heat-shock effects on LP were practically identical for Cd-exposed mussels in winter and summer, the effects were longer-lasting in summer than in winter for control mussels. Thus, lysosomal responsiveness after heat-shock was higher in summer than in winter but recovery was faster as well, and therefore the consequences of the heat shock seem to be more decisive in winter. In contrast, inter-season differences were attenuated in the presence of Cd. Consequently, mussels seem to be better prepared in summer than in winter to stand short periods of abrupt temperature change; this is, however, compromised when mussels are exposed to pollutants such as Cd. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessment of central auditory processing in a group of workers exposed to solvents.

PubMed

Fuente, Adrian; McPherson, Bradley; Muñoz, Verónica; Pablo Espina, Juan

2006-12-01

Despite having normal hearing thresholds and speech recognition thresholds, results for central auditory tests were abnormal in a group of workers exposed to solvents. Workers exposed to solvents may have difficulties in everyday listening situations that are not related to a decrement in hearing thresholds. A central auditory processing disorder may underlie these difficulties. To study central auditory processing abilities in a group of workers occupationally exposed to a mix of organic solvents. Ten workers exposed to a mix of organic solvents and 10 matched non-exposed workers were studied. The test battery comprised pure-tone audiometry, tympanometry, acoustic reflex measurement, acoustic reflex decay, dichotic digit, pitch pattern sequence, masking level difference, filtered speech, random gap detection and hearing-in-noise tests. All the workers presented normal hearing thresholds and no signs of middle ear abnormalities. Workers exposed to solvents had lower results in comparison with the control group and previously reported normative data, in the majority of the tests.

The effects of 30 mT electromagnetic fields on hippocampus cells of rats

PubMed Central

Teimori, Farzaneh; Khaki, Amir A.; Rajabzadeh, Asghar; Roshangar, Leila

2016-01-01

Background: Despite the use of electromagnetic waves in the treatment of some acute and chronic diseases, application of these waves in everyday life has created several problems for humans, especially the nerve system. In this study, the effects of 30mT electromagnetic fields (EMFs) on the hippocampus is investigated. Methods: Twenty-four 5-month Wistar rats weighing 150–200 g were divided into two groups. The experimental group rats were under the influence of an EMF at an intensity of 3 mT for approximately 4 hours a day (from 8 AM to 12 PM) during 10 weeks. After the hippocampus was removed, thin slides were prepared for transmission electron microscope (TEM) to study the ultrastructural tissue. Cell death detection POD kits were used to determine the apoptosis rate. Results: The results of the TEM showed that, in the hippocampus of the experimental group, in comparison to the control group, there was a substantial shift; even intracellular organelles such as the mitochondria were morphologically abnormal and uncertain. The number of apoptotic cells in the exposed group compared to the control group showed significant changes. Conclusions: Similar to numerous studies that have reported the effects of EMFs on nerves system, it was also confirmed in this lecture. Hence, the hippocampus which is important in regulating emotions, behavior, motivation, and memory functions, may be impaired by the negative impacts of EMFs. PMID:27453795

Impact of Magnetic Field on Pressures of Programmable Cerebrospinal Fluid Shunts: An Experimental Study.

PubMed

Altun, Idiris; Yuksel, Kasim Zafer; Mert, Tufan

2017-01-01

To investigate whether programmable cerebrospinal fluid (CSF) shunts are influenced by exposure to the magnetic field and to compare the effects of magnetic field in 4 different brands of programmable CSF shunts. This experimental study was performed in the laboratory using a novel design of magnetic field. Four types of programmable CSF shunts (Miethke®, Medtronic®, Sophysa® and Codman®Hakim®) were exposed to the magnetic field generated by an apparatus consisting of Helmholtz coil for 5 minutes. In every CSF shunt, initial pressures were adjusted to 110 mm H2O and pressures after exposure to magnetic field were noted. These measurements were implemented at frequencies of 5 Hz, 20 Hz, 30 Hz, 40 Hz, 60 Hz and 80 Hz. In each type, three shunts were utilized and evaluations were made twice for every shunt. At 5, 30, 40 and 60 Hz, Groups 1, 2 and 3 had significantly higher average pressures than Group 4. At 20 and 80 Hz, Groups 1 and 2 had notably different pressure values than Groups 3 and 4. Group 3 displayed the highest pressure, while Group 4 demonstrated the lowest pressure. Exposure to magnetic fields may affect the pressures of programmable CSF shunts. However, further controlled, clinical trials are warranted to elucidate the in-vivo effects of magnetic field exposure.

Orientation of pigeons exposed to constant light and released from familiar sites.

PubMed

Dall'Antonia, P; Luschi, P

1993-12-01

It has been proposed that homing pigeons may use pilotage to orient home when released from familiar sites. To test this possibility, a group of pigeons was released from familiar locations after being exposed to a constant bright light. This treatment produced the loss of the circadian rhythmicity of general activity of the birds and thus presumably impaired their time-compensating sun compass mechanism. Experimental birds, both anosmic and olfactorily unimpaired, did not show any tendency to orient home, their bearing distributions being generally not different from random. Their homing performances were also affected. These results show that initial orientation of pigeons released from familiar sites entails the use of the sun compass even when the birds are released after a treatment that makes them arrhythmic in their activity. The possibility that pilotage may play a role in the first part of the homing flight of pigeons remains to be demonstrated.

Aggregation effects on anhydrobiotic survival in the tardigrade Richtersius coronifer.

PubMed

Ivarsson, Helen; Jönsson, K Ingemar

2004-02-01

For anhydrobiotic metazoans the rate of desiccation is an important factor influencing the probability of survival in a dry anhydrobiotic state. Formation of animal aggregations, in which the exposed body surface area of individual animals is reduced, represents one way to reduce the rate of evaporation. Such aggregations have earlier been documented in e.g., nematodes. We experimentally evaluate the effect of aggregation size (number of animals in a group of desiccating animals) on anhydrobiotic survival in the eutardigrade Richtersius coronifer. The experiment shows that aggregation provides a clear improvement on anhydrobiotic survival. The most likely explanation for this is that aggregated animals were exposed to a lower rate of desiccation. Although the empirical evidence of aggregation in tardigrades is scarce, our study suggests that aggregation could potentially be an important survival factor for tardigrades living in environments characterized by periods of rapid desiccation. Copyright 2004 Wiley-Liss, Inc.

A new exposure model to evaluate smoked illicit drugs in rodents: A study of crack cocaine.

PubMed

Hueza, Isis M; Ponce, Fernando; Garcia, Raphael C T; Marcourakis, Tânia; Yonamine, Maurício; Mantovani, Cínthia de C; Kirsten, Thiago B

2016-01-01

The use of smoked illicit drugs has spread dramatically, but few studies use proper devices to expose animals to inhalational abused drugs despite the availability of numerous smoking devices that mimic tobacco exposure in rodents. Therefore, the present study developed an inexpensive device to easily expose laboratory animals to smoked drugs. We used crack cocaine as the drug of abuse, and the cocaine plasma levels and the behaviors of animals intoxicated with the crack cocaine were evaluated to prove inhaled drug absorption and systemic activity. We developed an acrylic device with two chambers that were interconnected and separated by a hatch. Three doses of crack (100, 250, or 500 mg), which contained 63.7% cocaine, were burned in a pipe, and the rats were exposed to the smoke for 5 or 10 min (n=5/amount/period). Exposure to the 250-mg dose for 10 min achieved cocaine plasma levels that were similar to those of users (170 ng/mL). Behavioral evaluations were also performed to validate the methodology. Rats (n=10/group) for these evaluations were exposed to 250 mg of crack cocaine or air for 10 min, twice daily, for 28 consecutive days. Open-field evaluations were performed at three different periods throughout the experimental design. Exposed animals exhibited transient anorexia, increased motor activity, and shorter stays in central areas of the open field, which suggests reduced anxiety. Therefore, the developed model effectively exposed animals to crack cocaine, and this model may be useful for the investigation of other inhalational abused drugs. Copyright © 2015 Elsevier Inc. All rights reserved.

Development of the Neuron Assessment for Measuring Biology Students’ Use of Experimental Design Concepts and Representations

PubMed Central

Dasgupta, Annwesa P.; Anderson, Trevor R.; Pelaez, Nancy J.

2016-01-01

Researchers, instructors, and funding bodies in biology education are unanimous about the importance of developing students’ competence in experimental design. Despite this, only limited measures are available for assessing such competence development, especially in the areas of molecular and cellular biology. Also, existing assessments do not measure how well students use standard symbolism to visualize biological experiments. We propose an assessment-design process that 1) provides background knowledge and questions for developers of new “experimentation assessments,” 2) elicits practices of representing experiments with conventional symbol systems, 3) determines how well the assessment reveals expert knowledge, and 4) determines how well the instrument exposes student knowledge and difficulties. To illustrate this process, we developed the Neuron Assessment and coded responses from a scientist and four undergraduate students using the Rubric for Experimental Design and the Concept-Reasoning Mode of representation (CRM) model. Some students demonstrated sound knowledge of concepts and representations. Other students demonstrated difficulty with depicting treatment and control group data or variability in experimental outcomes. Our process, which incorporates an authentic research situation that discriminates levels of visualization and experimentation abilities, shows potential for informing assessment design in other disciplines. PMID:27146159

A comparison of the in vitro cytotoxicity of conventional and resin modified glass ionomer cements

PubMed Central

Selimović-Dragaš, Mediha; Huseinbegović, Amina; Kobašlija, Sedin; Hatibović-Kofman, Šahza

2012-01-01

To evaluate cytotoxicity of experimental conventional and resin modified glass-ionomer cements on UMR-106 osteoblast cell cultures and cell cultures of NIH3T3 mouse fibroblasts specimens were prepared for every experimental material and divided into: group 1. Conventional glass-ionomer cements: GC Fuji IX GP Fast, GC Fuji Triage and Ketac Silver; group 2. Resin modified glass-ionomer cements: GC Fuji II LC, GC Fuji Plus and Vitrebond; group 3. Positive control was presented by specimens of composite Vit-l-ecence® and negative control-group 4. was presented by α-minimum essential medium for UMR-106 – osteoblast-like cells and Dulbecco’s Modified Eagle’s Medium for NIH3T3 mouse fibroblast cells. Both cell cultures were exposed to 10% of eluate of each single specimen of each experimental material. Experimental dishes were incubated for 24 h. Cell metabolism was evaluated using methyltetrazolium assay. Kruskal-Wallis test and Tukey-Kramer post hoc test for the materials evaluated on NIH3T3 mouse fibroblast cells, as well as UMR-106 osteoblast-like cells showed significantly more cytotoxicity of RMGICs, predominantly Vitrebond to both GICs and composite-Vit-l-ecence®. The lowest influence on cell’s metabolism on UMR-106 osteoblas-like cells was shown by Ketac Silver and the lowest influence on cell’s metabolism on NIH3T3 mouse fibroblast cells was shown by Fuji IX GP Fast. Statistical evaluation of sensitivity of cell lines UMR-106 osteoblast-like cells and NIH3T3 mouse fibroblast cells, using Mann-Whitney test, showed that NIH3T3 mouse fibroblast cells were more sensitive for the evaluation of cytotoxicity of dental materials. PMID:23198945

Effect of Cefotaxime on the CAT Activities and GSH Contents of Zebrafish

NASA Astrophysics Data System (ADS)

Wang, Yaxue; Shen, Hong-Yan

2018-05-01

In order to define eco-toxicity effect of cefotaxime on zebrafish, the indoor exposure method was used to study the impact of cefotaxime on zebrafish. In this study, zebrafish was exposed to cefotaxime of 1mg/L, 5mg/L, 25mg/L and 125mg/L for 15 days to study the effect of Catalase (CAT) activities and Glutathione (GSH) contents. According to the experimental data, the CAT activities and GSH contents in zebrafish muscle tissue had changed significantly during the period of exposure. The experimental results show that the activities of CAT in four concentration groups were significantly inhibited (P<0.01). The CAT activities in the 1 mg/L and 5 mg/L groups showed the "Λ" type change, inhibited first and induced later. But in the 25 mg/L and 125 mg/L groups, the CAT activities were inhibited all the time. Cefotaxime had a significant effect on GSH content in the muscle tissue of the zebrafish at the early stage of exposure, rapidly increase to the maximum at the early stage and rapidly decrease to the minimum on the 6th day. During 6th day to 15th day, the contents of GSH in the zebrafish were basically stable at the level of control. The experimental results show that the CAT activities and GSH contents in zebrafish muscle tissue had changed significantly.

Considerable decrease of antibody titers against measles, mumps, and rubella in preschool children from an e-waste recycling area.

PubMed

Lin, Yucong; Xu, Xijin; Dai, Yifeng; Zhang, Yuling; Li, Weiqiu; Huo, Xia

2016-12-15

Data on vaccination effects in children chronically exposed to heavy metals are extremely scarce. This study aims to investigate the immune responsiveness to measles, mumps, and rubella (MMR) vaccination in children from an e-waste recycling area. 378 healthy children from Guiyu (exposed group) and Haojiang (reference group) were surveyed. Blood lead (Pb) levels were measured by graphite furnace atomic absorption. Titers of antibodies against MMR were quantified by ELISA. Blood Pb levels of children from the exposed group were significantly higher than those from the reference group (5.61μg/dL vs. 3.57μg/dL, p<0.001). In contrast, the antibody titers against MMR of the children from the exposed group were significantly lower than those from the reference group. The median titer of the anti-measles antibody of the exposed group was 669.64mIU/mL, with an interquartile range of 372.88-1068.42mIU/mL; this was decreased by nearly 40% compared to that of the reference group (median 1046.79mIU/mL, interquartile range 603.29-1733.10mIU/mL). For antibody titers against mumps, there was an about 45% decrease in the exposed group (median 272.24U/mL, interquartile range 95.19-590.16U/mL), compared to the reference group (median 491.78U/mL, interquartile range 183.38-945.96U/mL). In the case of rubella, the median titer of the antibody was also significantly lower in the exposed group (median 37.08IU/mL, interquartile range 17.67-66.66IU/mL) compared to the reference group (median 66.50IU/mL, interquartile range 25.32-105.59IU/mL); the decrease in this case was nearly 44%. The proportion of children whose antibody titers against MMR were below protective level in the exposed group was higher than it was in the reference group. The present study demonstrates that the immune responsiveness to routine vaccination was suppressed in children chronically exposed to lead. Thus, the vaccination strategies for these children living in an e-waste recycling area should be modified. Copyright © 2016. Published by Elsevier B.V.

Effect of dimethyl sulfoxide wet-bonding technique on hybrid layer quality and dentin bond strength.

PubMed

Stape, Thiago Henrique Scarabello; Tjäderhane, Leo; Marques, Marcelo Rocha; Aguiar, Flávio Henrique Baggio; Martins, Luís Roberto Marcondes

2015-06-01

This study examined the effect of a dimethyl sulfoxide (DMSO) wet bonding technique on the resin infiltration depths at the bonded interface and dentin bond strength of different adhesive systems. Flat dentin surfaces of 48 human third molars were treated with 50% DMSO (experimental groups) or with distilled water (controls) before bonding using an etch-and-rinse (SBMP: Scotchbond Multi-Purpose, 3M ESPE) or a self-etch (Clearfil: Clearfil SE Bond, Kuraray) adhesive system. The restored crown segments (n=12/group) were stored in distilled water (24h) and sectioned for interfacial analysis of exposed collagen using Masson's Trichrome staining and for microtensile bond strength testing. The extent of exposed collagen was measured using light microscopy and a histometric analysis software. Failure modes were examined by SEM. Data was analyzed by two-way ANOVA followed by Tukey Test (α=0.05). The interaction of bonding protocol and adhesive system had significant effects on the extension of exposed collagen matrix (p<0.0001) and bond strength (p=0.0091). DMSO-wet bonding significantly reduced the extent of exposed collagen matrix for SBMP and Clearfil (p<0.05). Significant increase in dentin bond strength was observed on DMSO-treated specimens bonded with SBMP (p<0.05), while no differences were observed for Clearfil (p>0.05). DMSO-wet bonding was effective to improve the quality of resin-dentin bonds of the tested etch-and-rinse adhesives by reducing the extent of exposed collagen matrix at the base of the resin-dentin biopolymer. The improved penetration of adhesive monomers is reflected as an increase in the immediate bond strength when the DMSO-wet bonding technique is used with a water-based etch-and-rinse adhesive. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Effect of Restricting Access to Health Care on Health Expenditures among Asylum-Seekers and Refugees: A Quasi-Experimental Study in Germany, 1994–2013

PubMed Central

Bozorgmehr, Kayvan; Razum, Oliver

2015-01-01

Background Access to health care for asylum-seekers and refugees (AS&R) in Germany is initially restricted before regular access is granted, allegedly leading to delayed care and increasing costs of care. We analyse the effects of (a) restricted access; and (b) two major policy reforms (1997, 2007) on incident health expenditures for AS&R in 1994-2013. Methods and Findings We used annual, nation-wide, aggregate data of the German Federal Statistics Office (1994-2013) to compare incident health expenditures among AS&R with restricted access (exposed) to AS&R with regular access (unexposed). We calculated incidence rate differences (∆IRt) and rate ratios (IRRt), as well as attributable fractions among the exposed (AFe) and the total population (AFp). The effects of between-group differences in need, and of policy reforms, on differences in per capita expenditures were assessed in (segmented) linear regression models. The exposed and unexposed groups comprised 4.16 and 1.53 million person-years. Per capita expenditures (1994–2013) were higher in the group with restricted access in absolute (∆IRt = 375.80 Euros [375.77; 375.89]) and relative terms (IRR = 1.39). The AFe was 28.07% and the AFp 22.21%. Between-group differences in mean age and in the type of accommodation were the main independent predictors of between-group expenditure differences. Need variables explained 50-75% of the variation in between-group differences over time. The 1997 policy reform significantly increased ∆IRt adjusted for secular trends and between-group differences in age (by 600.0 Euros [212.6; 986.2]) and sex (by 867.0 Euros [390.9; 1342.5]). The 2007 policy reform had no such effect. Conclusion The cost of excluding AS&R from health care appears ultimately higher than granting regular access to care. Excess expenditures attributable to the restriction were substantial and could not be completely explained by differences in need. An evidence-informed discourse on access to health care for AS&R in Germany is needed; it urgently requires high-quality, individual-level data. PMID:26201017

Effect of Restricting Access to Health Care on Health Expenditures among Asylum-Seekers and Refugees: A Quasi-Experimental Study in Germany, 1994-2013.

PubMed

Bozorgmehr, Kayvan; Razum, Oliver

2015-01-01

Access to health care for asylum-seekers and refugees (AS&R) in Germany is initially restricted before regular access is granted, allegedly leading to delayed care and increasing costs of care. We analyse the effects of (a) restricted access; and (b) two major policy reforms (1997, 2007) on incident health expenditures for AS&R in 1994-2013. We used annual, nation-wide, aggregate data of the German Federal Statistics Office (1994-2013) to compare incident health expenditures among AS&R with restricted access (exposed) to AS&R with regular access (unexposed). We calculated incidence rate differences (∆IRt) and rate ratios (IRRt), as well as attributable fractions among the exposed (AFe) and the total population (AFp). The effects of between-group differences in need, and of policy reforms, on differences in per capita expenditures were assessed in (segmented) linear regression models. The exposed and unexposed groups comprised 4.16 and 1.53 million person-years. Per capita expenditures (1994-2013) were higher in the group with restricted access in absolute (∆IRt = 375.80 Euros [375.77; 375.89]) and relative terms (IRR = 1.39). The AFe was 28.07% and the AFp 22.21%. Between-group differences in mean age and in the type of accommodation were the main independent predictors of between-group expenditure differences. Need variables explained 50-75% of the variation in between-group differences over time. The 1997 policy reform significantly increased ∆IRt adjusted for secular trends and between-group differences in age (by 600.0 Euros [212.6; 986.2]) and sex (by 867.0 Euros [390.9; 1342.5]). The 2007 policy reform had no such effect. The cost of excluding AS&R from health care appears ultimately higher than granting regular access to care. Excess expenditures attributable to the restriction were substantial and could not be completely explained by differences in need. An evidence-informed discourse on access to health care for AS&R in Germany is needed; it urgently requires high-quality, individual-level data.

Diesel Exhaust Particle-Induced Airway Responses are Augmented in Obese Rats

PubMed Central

Moon, Kuk-Young; Park, Moo-Kyun; Leikauf, George D.; Park, Choon-Sik; Jang, An-Soo

2015-01-01

Air pollutants and obesity are important factors that contribute to asthma. The aim of this study was to assess the airway responsiveness and inflammation in Otsuka-Long Evans Tokushima Fatty (OLETF) obese rats and Long Evans Tokushima-Otsuka (LETO) nonobese rats exposed to diesel exhaust particles (DEPs). Otsuka Long Evans Tokushima fatty rats and LETO rats were exposed intranasally to DEP and then challenged with aerosolized DEP on days 6 to 8. Body plethysmography, bronchoalveolar lavage (BAL), and histology were performed. Enhanced pause (Penh) was measured as an indicator of airway resistance on day 9 and samples were collected on day 10. After exposure to DEP, the OLETF group exhibited a greater increase in Penh compared to that in the LETO group. Moreover, the BAL fluid in mice showed an increase in the total and differential cell counts in the DEP-exposed OLETF group compared to that in the DEP-exposed LETO group. Histological assessment of lung tissue from each group revealed that the DEP-exposed OLETF group tended to have increased inflammatory cell infiltrations in the prebronchial area. Increased peroxisome proliferator-activated receptor γ, coactivator 1β messenger RNA was observed in the lungs of obese rats compared to that in nonobese rats following DEP exposure. These data indicate that the DEP-exposed OLETF group had increased airway responses and inflammation compared to the DEP-exposed LETO group, indicating that diesel particulates and obesity may be co-contributors to asthma. PMID:24536021

Laser fluorescence of dentin caries covered with a novel nano-filled sealant.

PubMed

Braun, Andreas; Beisel, Christian; Brede, Olivier; Krause, Felix

2013-01-01

The aim of the present study was to assess the possibility to measure caries-induced laser fluorescence underneath a novel nano-filled fissure sealant. Sixty freshly extracted human teeth with occlusal dentine carious lesions were horizontally divided, exposing the respective lesion. Teeth were randomly assigned to three groups: (I) white fissure sealant with filler particles (Fissurit F, Voco), (II) clear fissure sealant without filler particles (Fissurit, Voco) and (III) novel experimental fissure sealant with nano-filler particles (Voco). Starting with a sealant thickness of 3 mm, laser fluorescence measurements (DIAGNOdent, KaVo) were performed after finishing the sealant surfaces with polishing papers, reducing the material at intervals of 0.5 mm until the sealant was removed completely. Evaluating a thickness of 0.5 mm, both the clear (83 % of the baseline fluorescence after fine grit polishing) and the white sealant (25 %) did not allow to measure baseline fluorescence (p < 0.05) with no fluorescence reduction in the experimental sealant group (p > 0.05). With increasing sealer thickness, fluorescence was influenced even by the experimental material (89 % of the baseline value at 1 mm). However, by using the experimental material, statistically significant higher fluorescence values than those for the other materials under study (p < 0.05) were obtained. Thicker sealant layers and coarse grit polishing caused a decrease of laser fluorescence in all groups (p < 0.05). Employing the experimental nano-filled sealant, laser fluorescence measurements for caries detection can be performed through thicker sealant layers compared to conventional sealant materials. Thus, it might be possible to use this material to assess a caries progression underneath the sealant and administer an appropriate therapy in due time.

Effects of Sesame (Sesamum indicum L.) Supplementation on Creatine Kinase, Lactate Dehydrogenase, Oxidative Stress Markers, and Aerobic Capacity in Semi-Professional Soccer Players

PubMed Central

Barbosa, Carlos V. da Silva; Silva, Alexandre S.; de Oliveira, Caio V. C.; Massa, Nayara M. L.; de Sousa, Yasmim R. F.; da Costa, Whyara K. A.; Silva, Ayice C.; Delatorre, Plínio; Carvalho, Rhayane; Braga, Valdir de Andrade; Magnani, Marciane

2017-01-01

Nutritional intervention with antioxidants rich foods has been considered a strategy to minimize the effects of overtraining in athletes. This experimental, randomized, and placebo-controlled study evaluated the effects of consumption of sesame (Sesamum indicum L.) on muscle damage markers, oxidative stress, systemic inflammation, and aerobic performance in male semi-professional soccer players. Twenty athletes were randomly assigned to groups that received 40 g (two tablespoons) per day of sesame or a placebo during 28 days of regular training (exposed to routine training that includes loads of heavy training in the final half of the season). Before and after intervention, creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), C-reactive protein (hs-CRP), and aerobic capacity were evaluated. Before intervention, a physiologic imbalance was noted in both groups related to CK and LDH levels. Sesame intake caused a reduction of CK (19%, p < 0.05), LDH (37%, p < 0.05), MDA (55%, p < 0.05) and hs-CRP (53%, p < 0.05) and increased SOD (14%, p < 0.05), vitamin A (25%, p < 0.05), and vitamin E (65%, p < 0.05) in the experimental group. These phenomena were accompanied by increased aerobic capacity (17%, p < 0.05). The placebo group showed an increase in CK (5%, p < 0.05) and no significant change in LDH, SOD or vitamin A. MDA levels decreased (21%, p < 0.05) and vitamin E increased (14%, p < 0.05) in the placebo group, but to a much lesser extent than in the experimental group. These results show that sesame consumption may reduce muscle damage and oxidative stress while improving the aerobic capacity in soccer players. PMID:28408889

Effect of vitamin C and E supplementation on total antioxidant content of human breastmilk and infant urine.

PubMed

Zarban, Asghar; Toroghi, Mahsa Mostafavi; Asli, Marziye; Jafari, Masumeh; Vejdan, Morteza; Sharifzadeh, Gholamreza

2015-05-01

After delivery and birth, mothers and neonates are exposed to oxidative stress. The present study examined the effect of supplementation of the diet of breastfeeding mothers with vitamin C and E to improve the antioxidant content of breastmilk and evidence of antioxidant activity in infant urine. The subjects were 60 healthy lactating breastfeeding mothers and their infants 1-6 months of age. They were randomly allocated to a control group (n=30) consuming a free diet or an experimental group (n=30) consuming a free diet supplemented each day with effervescent tablets of vitamin C (500 mg) and chewable tablets of vitamin E (100 IU). After 30 days, the total antioxidant content of the mothers' breastmilk and evidence of antioxidant activity in the infants' urine were measured by the ferric reducing/antioxidant power assay. The free radical scavenging activity of the urine samples was measured by the α,α-diphenyl-β-picrylhydrazyl method. Differences pre- and postintervention were compared within and between the groups. Significantly higher levels of antioxidants in the breastmilk (610±295.5 to 716±237.5 μmol/L) and infant urine (43.2±21.8 to 75.0±49.2 μmol/mg creatinine) were observed in the experimental group over the control group (p<0.05). A significant increase in evidence of free radical scavenging in infant urine was observed in the experimental group after 30 days of supplementation by mothers (p<0.05). Consumption of vitamin C and E supplements appears to have a positive effect on total antioxidant content of breastmilk and evidence of antioxidant activity in infant urine.

The effects of ethanol and strontium on growth and development of two-cell arrested mouse embryos.

PubMed

Darabi, Mohammad Reza; Shiravi, Abdolhossein; Hojati, Vida

2012-01-01

Arresting at a certain stage of development like the two-cell stage could be one of the causes of infertility. The aim of this study is to evaluate the effects of ethanol and strontium on growth and development of mice embryos arrested at the two-cell stage. In this experimental study, female mice were coupled with a male following superovulation. Positive vaginal plug mice were sacrificed 48 hours after human chorionic gonadotropin (hCG) injection. Two-cell embryos were transferred to M16 medium and divided to four groups. The first control group was incubated without any exposure to low temperatures. Groups 2, 3 and 4 were exposed to 4°C for 24 hours. The second control group was incubated immediately, while the third and fourth groups were exposed to 10 mM strontium for five minutes and 0.1% ethanol for a further five minutes. Growth rate and developmental parameters of embryos were analyzed by one- way ANOVA. The significant difference between the groups was determined by Post Hoc. The data shows that developmental rate is decreased significantly by 4°C exposure. The mean percentage of degenerated embryo was significantly different between groups but the mean cleavage rate was not significantly different. The mean percent of morula, blastocyst and hatched blastocyst formation were significantly different between groups during a 120 hours study post hCG injection. The effect of strontium and ethanol on arrested two-cell embryos had no significant effect on the mean percentage of morula, but ethanol treatment significantly increased the percentage of blastocyst and hatched blastocyst formation compared to strontium.

Improvement of functional recovery of transected peripheral nerve by means of chitosan grafts filled with vitamin E, pyrroloquinoline quinone and their combination.

PubMed

Azizi, Asghar; Azizi, Saeed; Heshmatian, Behnam; Amini, Keyvan

2014-01-01

Effects of vitamin E and pyrroloquinoline quinone on peripheral nerve regeneration were studied using a rat sciatic nerve transection model. Ninety male healthy White Wistar rats were divided into three experimental groups (n = 15), randomly: Sham-operation (SHAM), transected control (TC), chitosan conduit (Chit) and three treatment groups (Vit E, PQQ and PQQ + Vit E). In SHAM group after anesthesia, left sciatic nerve was exposed through a gluteal muscle incision and after homeostasis muscle was sutured. In Chit group left sciatic nerve was exposed the same way and transected proximal to tibio-peroneal bifurcation leaving a 10-mm gap. Proximal and distal stumps were each inserted into a chitosan tube. In treatment groups the tube was implanted the same way and filled with Vit E, PQQ and PQQ + Vit E. Each group was subdivided into three subgroups of six animals each and were studied 4, 8, 12 weeks after surgery. Functional and electrophysiological studies, and gastrocnemius muscle mass measurement confirmed faster and better recovery of regenerated axons in Vit E + PQQ combination compared to Vit E or PQQ solely (P < 0.05). Morphometric indices of regenerated fibers showed number and diameter of the myelinated fibers in PQQ + Vit E was significantly higher than in other treatment groups. In immunohistochemistry, location of reactions to S-100 in PQQ + Vit E was clearly more positive than in other treatment groups. Response to PQQ + Vit E treatment demonstrates that it influences and improves functional recovery of peripheral nerve regeneration. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Indexing Guidelines: Applications in Use of Pulmonary Artery Catheters and Pressure Ulcer Prevention

PubMed Central

Jenders, Robert A.; Estey, Greg; Martin, Martha; Hamilton, Glenys; Ford-Carleton, Penny; Thompson, B. Taylor; Oliver, Diane E.; Eccles, Randy; Barnett, G. Octo; Zielstorff, Rita D.; Fitzmaurice, Joan B.

1994-01-01

In a busy clinical environment, access to knowledge must be rapid and specific to the clinical query at hand. This requires indices which support easy navigation within a knowledge source. We have developed a computer-based tool for trouble-shooting pulmonary artery waveforms using a graphical index. Preliminary results of domain knowledge tests for a group of clinicians exposed to the system (N=33) show a mean improvement on a 30-point test of 5.33 (p<0.001) compared to a control group (N=19) improvement of 0.47 (p=0.61). Survey of the experimental group (N=25) showed 84% (p=0.001) found the system easy to use. We discuss lessons learned in indexing this domain area to computer-based indexing of guidelines for pressure ulcer prevention. PMID:7950035

Influence of chlorhexidine on dentin adhesive interface micromorphology and nanoleakage expression of resin cements.

PubMed

Stape, Thiago Henrique Scarabello; Menezes, Murilo De Sousa; Barreto, Bruno De Castro Ferreira; Naves, Lucas Zago; Aguiar, Flávio Henrique Baggio; Quagliatto, Paulo Sérgio; Martins, Luís Roberto Marcondes

2013-08-01

This study focused on adhesive interface morphologic characterization and nanoleakage expression of resin cements bonded to human dentin pretreated with 1% chlorhexidine (CHX). Thirty-two non-carious human third molars were ground flat to expose superficial dentin. Resin composite blocks were luted to the exposed dentin using one conventional (RelyX ARC) and one self-adhesive resin cement (RelyX U100), with/without CHX pretreatment. Four groups (n = 8) were obtained: control groups (ARC and U100); experimental groups (ARC/CHX and U100/CHX) were pretreated with 1% CHX prior to the luting process. After storage in water for 24 h, the bonded teeth were sectioned into 0.9 × 0.9 mm(2) sticks producing a minimum of 12 sticks per tooth. Four sticks from each tooth were prepared for hybrid layer evaluation by scanning electron microscope analysis. The remaining sticks were immersed in silver nitrate for 24 h for either nanoleakage evaluation along the bonded interfaces or after rupture. Nanoleakage samples were carbon coated and examined using backscattered electron mode. Well-established hybrid layers were observed in the groups luted with RelyX ARC. Nanoleakage evaluation revealed increase nanoleakage in groups treated with CHX for both resin cements. Group U100/CHX exhibited the most pronouncing nanoleakage expression along with porous zones adjacent to the CHX pretreated dentin. The results suggest a possible incompatibility between CHX and RelyX U100 that raises the concern that the use of CHX with self-adhesive cements may adversely affect resin-dentin bond. Copyright © 2013 Wiley Periodicals, Inc.

Exploring Robust Methods for Evaluating Treatment and Comparison Groups in Chronic Care Management Programs

PubMed Central

Hamar, Brent; Bradley, Chastity; Gandy, William M.; Harrison, Patricia L.; Sidney, James A.; Coberley, Carter R.; Rula, Elizabeth Y.; Pope, James E.

2013-01-01

Abstract Evaluation of chronic care management (CCM) programs is necessary to determine the behavioral, clinical, and financial value of the programs. Financial outcomes of members who are exposed to interventions (treatment group) typically are compared to those not exposed (comparison group) in a quasi-experimental study design. However, because member assignment is not randomized, outcomes reported from these designs may be biased or inefficient if study groups are not comparable or balanced prior to analysis. Two matching techniques used to achieve balanced groups are Propensity Score Matching (PSM) and Coarsened Exact Matching (CEM). Unlike PSM, CEM has been shown to yield estimates of causal (program) effects that are lowest in variance and bias for any given sample size. The objective of this case study was to provide a comprehensive comparison of these 2 matching methods within an evaluation of a CCM program administered to a large health plan during a 2-year time period. Descriptive and statistical methods were used to assess the level of balance between comparison and treatment members pre matching. Compared with PSM, CEM retained more members, achieved better balance between matched members, and resulted in a statistically insignificant Wald test statistic for group aggregation. In terms of program performance, the results showed an overall higher medical cost savings among treatment members matched using CEM compared with those matched using PSM (-$25.57 versus -$19.78, respectively). Collectively, the results suggest CEM is a viable alternative, if not the most appropriate matching method, to apply when evaluating CCM program performance. (Population Health Management 2013;16:35–45) PMID:22788834

Growth performance and protective effect of vitamin E on oxidative stress pufferfish (Takifugu obscurus) following by ammonia stress.

PubMed

Cheng, Chang-Hong; Guo, Zhi-Xun; Wang, An-Li

2018-04-01

This study was conducted to determine the effects of vitamin E on growth performance, biochemical parameters, and antioxidant capacity of pufferfish (Takifugu obscurus) exposed to ammonia stress. The experimental basal diets supplemented with vitamin E at the rates of 2.31 (control), 21.84, 40.23, 83.64, 158.93, and 311.64 mg kg -1 dry weight were fed to fish for 60 days. After the feeding trial, the fish were exposed to 100 mg L -1 ammonia-nitrogen for 48 h. The results shown that the vitamin E group significantly improved weight gain, specific growth rate, and the expression levels of growth hormone receptors and insulin-like growth factor. Fish fed with the vitamin E-supplemented diets could increase plasma alkaline phosphatase activities and decrease plasma glutamicoxalacetic transaminase and glutamic-pyruvic transaminase activities. The relative expression levels of heat shock proteins (40.23-311.64 mg kg -1 vitamin E diet group), manganese superoxide dismutase (83.64-158.93 mg kg -1 vitamin E diet group), catalase (40.23-311.64 mg kg -1 vitamin E diet group), and glutathione reductase (40.23-311.64 mg kg -1 vitamin E diet group) were upregulated. On the other hand, the decreased level of reactive oxygen species (ROS) was observed in the 83.64-311.64 mg kg -1 vitamin E additive group. These results showed that vitamin E might have a potentially useful role as an effective antioxidant to improve resistance in pufferfish.

Exploring robust methods for evaluating treatment and comparison groups in chronic care management programs.

PubMed

Wells, Aaron R; Hamar, Brent; Bradley, Chastity; Gandy, William M; Harrison, Patricia L; Sidney, James A; Coberley, Carter R; Rula, Elizabeth Y; Pope, James E

2013-02-01

Evaluation of chronic care management (CCM) programs is necessary to determine the behavioral, clinical, and financial value of the programs. Financial outcomes of members who are exposed to interventions (treatment group) typically are compared to those not exposed (comparison group) in a quasi-experimental study design. However, because member assignment is not randomized, outcomes reported from these designs may be biased or inefficient if study groups are not comparable or balanced prior to analysis. Two matching techniques used to achieve balanced groups are Propensity Score Matching (PSM) and Coarsened Exact Matching (CEM). Unlike PSM, CEM has been shown to yield estimates of causal (program) effects that are lowest in variance and bias for any given sample size. The objective of this case study was to provide a comprehensive comparison of these 2 matching methods within an evaluation of a CCM program administered to a large health plan during a 2-year time period. Descriptive and statistical methods were used to assess the level of balance between comparison and treatment members pre matching. Compared with PSM, CEM retained more members, achieved better balance between matched members, and resulted in a statistically insignificant Wald test statistic for group aggregation. In terms of program performance, the results showed an overall higher medical cost savings among treatment members matched using CEM compared with those matched using PSM (-$25.57 versus -$19.78, respectively). Collectively, the results suggest CEM is a viable alternative, if not the most appropriate matching method, to apply when evaluating CCM program performance.

Effect of carbonated water manufactured by a soda carbonator on etched or sealed enamel

PubMed Central

Ryu, Hyo-kyung; Kim, Yong-do; Heo, Sung-su

2018-01-01

Objective The purpose of this study was to determine the effects of carbonated water on etched or sealed enamel according to the carbonation level and the presence of calcium ions. Methods Carbonated water with different carbonation levels was manufactured by a soda carbonator. Seventy-five premolar teeth were randomly divided into a control group and 4 experimental groups in accordance with the carbonation level and the presence of calcium ions in the test solutions. After specimen preparation of the Unexposed, Etched, and Sealed enamel subgroups, all the specimens were submerged in each test solution for 15 minutes three times a day during 7 days. Microhardness tests on the Unexposed and Etched enamel subgroups were performed with 10 specimens from each group. Scanning electron microscopy (SEM) tests on the Unexposed, Etched, and Sealed enamel subgroups were performed with 5 specimens from each group. Microhardness changes in different groups were statistically compared using paired t-tests, the Wilcoxon signed rank test, and the Kruskal-Wallis test. Results The microhardness changes were significantly different between the groups (p = 0.000). The microhardness changes in all experimental groups except Group 3 (low-level carbonated water with calcium ions) were significantly greater than those in the Control group. SEM showed that etched areas of the specimen were affected by carbonated water and the magnitude of destruction varied between groups. Adhesive material was partially removed in groups exposed to carbonated water. Conclusions Carbonated water has negative effects on etched or sealed enamel, resulting in decreased microhardness and removal of the adhesive material. PMID:29291188

Auditory Brainstem Responses for Click and CE-chirp Stimuli in Individuals with and without Occupational Noise Exposure

PubMed Central

Pushpalatha, Zeena Venkatacheluvaiah; Konadath, Sreeraj

2016-01-01

Introduction: Encoding of CE-chirp and click stimuli in auditory system was studied using auditory brainstem responses (ABRs) among individuals with and without noise exposure. Materials and Methods: The study consisted of two groups. Group 1 (experimental group) consisted of 20 (40 ears) individuals exposed to occupational noise with hearing thresholds within 25 dB HL. They were further divided into three subgroups based on duration of noise exposure (0–5 years of exposure-T1, 5–10 years of exposure-T2, and >10 years of exposure-T3). Group 2 (control group) consisted of 20 individuals (40 ears). Absolute latency and amplitude of waves I, III, and V were compared between the two groups for both click and CE-chirp stimuli. T1, T2, and T3 groups were compared for the same parameters to see the effect of noise exposure duration on CE-chirp and click ABR. Result: In Click ABR, while both the parameters for wave III were significantly poorer for the experimental group, wave V showed a significant decline in terms of amplitude only. There was no significant difference obtained for any of the parameters for wave I. In CE-Chirp ABR, the latencies for all three waves were significantly prolonged in the experimental group. However, there was a significant decrease in terms of amplitude in only wave V for the same group. Discussion: Compared to click evoked ABR, CE-Chirp ABR was found to be more sensitive in comparison of latency parameters in individuals with occupational noise exposure. Monitoring of early pathological changes at the brainstem level can be studied effectively by using CE-Chirp stimulus in comparison to click stimulus. Conclusion: This study indicates that ABR's obtained with CE-chirp stimuli serves as an effective tool to identify the early pathological changes due to occupational noise exposure when compared to click evoked ABR. PMID:27762255

NTP Toxicology and Carcinogenesis Studies of Molybdenum Trioxide (CAS No. 1313-27-5) in F344 Rats and B6C3F1 Mice (Inhalation Studies).

PubMed

1997-04-01

Molybdenum is an essential element for the function of nitrogenase in plants and as a cofactor for enzymes including xanthine oxidoreductase, aldehyde oxidase, and sulfide oxidase in animals. Molybdenum trioxide is used primarily as an additive to steel and corrosion-resistant alloys. It is also used as a chemical intermediate for molybdenum products; an industrial catalyst; a pigment; a crop nutrient; components of glass, ceramics, and enamels; a flame retardant for polyester and polyvinyl chloride resins; and a reagent in chemical analyses. Molybdenum trioxide was nominated by the NCI for toxicity and carcinogenicity studies as a representative inorganic molybdenum compound. The production of molybdenum trioxide is the largest of all the molybdenum compounds examined. Male and female F344/N rats and B6C3F1 mice were exposed to molybdenum trioxide (approximately 99% pure) by inhalation for 14 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and cultured Chinese hamster ovary cells. 14-DAY STUDY IN RATS: Groups of five male and five female F344/N rats were exposed to 0, 3, 10, 30, 100, or 300 mg molybdenum trioxide/m(3). Rats were exposed for 6 hours per day, 5 days per week, for a total of 10 exposure days during a 14-day period. All rats survived to the end of the study. The final mean body weights of male rats exposed to 100 mg/m(3) and male and female rats exposed to 300 mg/m(3) were significantly lower than those of the control groups. Male rats exposed to 300 mg/m(3) lost weight during the study. There were no clinical findings related to exposure to molybdenum trioxide. No chemical-related lesions were observed. 14-DAY STUDY IN MICE: Groups of five male and five female B6C3F1 mice were exposed to 0, 3, 10, 30, 100, or 300 mg molybdenum trioxide/m(3). Mice were exposed 6 hours per day, 5 days per week, for a total of 10 exposure days during a 14-day period. All mice survived to the end of the study. Final mean body weights of male and female mice exposed to 300 mg/m(3) were significantly lower than those of the control groups. Male mice exposed to 300 mg/m(3) lost weight during the study. There were no clinical findings related to exposure to molybdenum trioxide. No chemical-related lesions were observed. 13-WEEK STUDY IN RATS: Groups of 10 male and 10 female F344/N rats were exposed to molybdenum trioxide by inhalation at concentrations of 0, 1, 3, 10, 30, or 100 mg/m(3) for 6.5 hours per day, 5 days per week, for 13 weeks. All rats survived to the end of the study. The final mean body weights of exposed rats were similar to those of the control groups. No clinical findings related to molybdenum trioxide exposure were observed. There were no significant chemical-related differences in absolute or relative organ weights, hematology or clinical chemistry parameters, sperm counts or motility, or liver copper concentrations between control and exposed rats. No chemical-related lesions were observed. 13-WEEK STUDY IN MICE: Groups of 10 male and 10 female B6C3F1 mice were exposed to molybdenum trioxide by inhalation at concentrations of 0, 1, 3, 10, 30, or 100 mg/m(3) for 6.5 hours per day, 5 days per week, for 13 weeks. All mice survived to the end of the study. The final mean body weights of exposed mice were similar to those of the control groups. There were no chemical-related clinical findings. There were no significant differences in absolute or relative organ weights or sperm counts or motility between control and exposed mice. There were significant increases in liver copper concentrations in female mice exposed to 30 mg/m(3) and in male and female mice exposed to 100 mg/m(3) compared to those of the control groups. No chemical-related lesions were observed. 2-YEAR STUDIES IN RATS: Groups of 50 male and 50 female F344/N rats were exposed to molybdenum trioxide by inhalation at concentrations of 0, 10, 30, or 100 mg/m(3). Rats were exposed for 6 hours per day, 5 days per week, for 106 weeks. Survival, Body Weights, and Special Studies: Survival rates of exposed maleed male and female rats were similar to those of the control groups. Mean body weights of exposed groups of male and female rats were similar to those of the control groups throughout the study. There was a significant exposure-dependent increase in blood molybdenum concentration in exposed rats. Blood concentrations of molybdenum in exposed male rats were greater than those in exposed female rats. There were no toxicologically significant differences in bone density or curvature between control and exposed rats. Pathology Findings: The incidences of alveolar/bronchiolar adenoma or carcinoma (combined) were increased in male rats with a marginally significant positive trend. No increase in the incidences of lung neoplasms occurred in female rats. Incidences of chronic alveolar inflammation in male and female rats exposed to 30 or 100 mg/m(3) were significantly greater than those in the control groups. No nasal or laryngeal neoplasms were attributed to exposure to molybdenum trioxide. Incidences of hyaline degeneration in the nasal respiratory epithelium in 30 and 100 mg/m(3) males and in all exposed groups of females were significantly greater than those in the control groups. The incidences of hyaline degeneration in the nasal olfactory epithelium of all exposed groups of females were significantly greater than that in the control group. In the larynx, incidences of squamous metaplasia of the epithelium lining the base of the epiglottis in all exposed groups of male and female rats were significantly greater than those in the control groups and increased with increasing exposure concentration. 2-YEAR STUDY IN MICE: Groups of 50 male and 50 female B6C3F1 mice were exposed to molybdenum trioxide by inhalation at concentrations of 0, 10, 30, or 100 mg/m(3). Mice were exposed for 6 hours per day, 5 days per week, for 105 weeks. Survival, Body Weights, and Special Studies: The survival rate of male mice exposed to 30 mg/m(3) was marginally lower than that of the control group; survival rates of 10 and 100 mg/m(3) males and of all exposed groups of females were similar to those of the control groups. Mean body weights of exposed male mice were generally similar to those of the control group throughout the study. Mean body weights of exposed female mice were generally greater than those of the control group from week 11 until the end of the study. There was a significant exposure-dependent increase in blood molybdenum concentration in exposed mice. There were no toxicologically significant differences in bone density or curvature between control and exposed mice. Pathology Findings: The incidences of alveolar/bronchiolar carcinoma in all exposed groups of males were significantly greater than that in the control group. Incidences of alveolar/bronchiolar adenoma in females in the 30 and 100 mg/m(3) groups were significantly greater than that in the control group. Incidences of alveolar/bronchiolar adenoma or carcinoma (combined) in 10 and 30 mg/m(3) males and in 100 mg/m(3) females were significantly greater than those in the control groups and exceeded the historical control ranges for 2-year NTP inhalation studies. Incidences of metaplasia of the alveolar epithelium of minimal severity in the centriacinar region of the lung were significantly increased in all exposed groups of mice. The incidences of histiocyte cellular infiltration in all exposed groups of males were significantly greater than that in the control group. Incidences of hyaline degeneration of the respiratory epithelium of the nasal cavity in 100 mg/m(3) males and females and hyaline degeneration of the olfactory epithelium of the nasal cavity in 100 mg/m(3) females were significantly greater than those in the control groups. The incidences of squamous metaplasia of the epithelium lining the base of the epiglottis were significantly increased in all exposed groups of males and females. In both male and female mice, the incidences of hyperplasia of the laryngeal epithelium in level II of the larynx increased with increasing exposure concentration. The increase was statistically significant only in mice exposed to 100 mg/m(3) with 82% of male and 70% of female mice affected. GENETIC TOXICOLOGY: Molybdenum trioxide was not mutagenic in any of five strains of Salmonella typhimurium, and it did not induce sister chromatid exchanges or chromosomal aberrations in cultured Chinese hamster ovary cells in vitro. All tests were conducted with and without S9 metabolic activation enzymes. CONCLUSIONS: Under the conditions of these 2-year inhalation studies, there was equivocal evidence of carcinogenic activity of molybdenum trioxide in male F344/N rats based on a marginally significant positive trend of alveolar/bronchiolar adenoma or carcinoma (combined). There was no evidence of carcinogenic activity of molybdenum trioxide in female F344/N rats exposed to 10, 30, or 100 mg/m(3). There was some evidence of carcinogenic activity of molybdenum trioxide in male B6C3F1 mice based on increased incidences of alveolar/bronchiolar carcinoma and adenoma or carcinoma (combined). There was some evidence of carcinogenic activity of molybdenum trioxide in female B6C3F1 mice based on increased incidences of alveolar/bronchiolar adenoma and adenoma or carcinoma (combined). Exposure of male and female rats to molybdenum trioxide by inhalation resulted in increased incidences of chronic alveolar inflammation, hyaline degeneration of the respiratory epithelium, hyaline degeneration of the olfactory epithelium (females), and squamous metaplasia of the epiglottis. Exposure of male and female mice to molybdenum trioxide by inhalation resulted in increased incidences of metaplasia of the alveolar epithelium, histiocyte cellular infiltration (males), hyaline degeneration of the respiratory epithelium, hyaline degeneration of the olfactory epithelium (females), squamous metaplasia of the epiglottis, and hyperplasia of the larynx. Synonyms: Molybdic oxide; molybdic trioxide; molybdic anhydride; molybdenum (VI) oxide; molybdenum peroxide; molybdic acid anhydride; molybdenum anhydride; natural molybdite; molybdena

No neurochemical evidence of brain injury after blast overpressure by repeated explosions or firing heavy weapons.

PubMed

Blennow, K; Jonsson, M; Andreasen, N; Rosengren, L; Wallin, A; Hellström, P A; Zetterberg, H

2011-04-01

Psychiatric and neurological symptoms are common among soldiers exposed to blast without suffering a direct head injury. It is not known whether such symptoms are direct consequences of blast overpressure. To examine if repeated detonating explosions or firing if of heavy weapons is associated with neurochemical evidence of brain damage. Three controlled experimental studies. In the first, army officers were exposed to repeated firing of a FH77B howitzer or a bazooka. Cerebrospinal fluid (CSF) was taken post-exposure to measure biomarkers for brain damage. In the second, officers were exposed for up to 150 blasts by firing a bazooka, and in the third to 100 charges of detonating explosives of 180 dB. Serial serum samples were taken after exposure. Results were compared with a control group consisting of 19 unexposed age-matched healthy volunteers. The CSF biomarkers for neuronal/axonal damage (tau and neurofilament protein), glial cell injury (GFAP and S-100b), blood-brain barrier damage (CSF/serum albumin ratio) and hemorrhages (hemoglobin and bilirubin) and the serum GFAP and S-100b showed normal and stable levels in all exposed officers. Repeated exposure to high-impact blast does not result in any neurochemical evidence of brain damage. These findings are of importance for soldiers regularly exposed to high-impact blast when firing artillery shells or other types of heavy weapons. © 2010 John Wiley & Sons A/S.

Vanadium Exposure-Induced Neurobehavioral Alterations among Chinese Workers

PubMed Central

Li, Hong; Zhou, Dinglun; Zhang, Qin; Feng, Chengyong; Zheng, Wei; He, Keping; Lan, Yajia

2014-01-01

Vanadium-containing products are manufactured and widely used in the modern industry. Yet the neurobehavioral toxicity due to occupational exposure to vanadium remained elusive. This cross-sectional study was designed to examine the neurotoxic effects of occupational vanadium exposure. A total of 463 vanadium-exposed workers (exposed group) and 251 non-exposed workers (control group) were recruited from a Steel and Iron Group in Sichuan, China. A WHO-recommended neurobehavioral core test battery (NCTB) and event-related auditory evoked potentials test (P300) were used to assess the neurobehavioral functions of all study subjects. A general linear model was used to compare outcome scores between the two groups while controlling for possible confounders. The exposed group showed a statistically significant neurobehavioral alteration more than the control group in the NCTB tests. The exposed workers also exhibited an increased anger-hostility, depression-dejection and fatigue-inertia on the profile of mood states (p<0.05). Performances in the Simple Reaction Time, Digit Span, Benton Visual Retention and Pursuit Aiming were also poorer among exposed workers as compared to unexposed control workers(p<0.05). Some of these poor performances in tests were also significantly related to workers’ exposure duration. P300 latencies were longer in the exposed group than in the control (p<0.05). Longer mean reaction times and more counting errors were also found in the exposed workers (p<0.05). Given the findings of our study and the limitations of neurobehavioral workplace testing, we found evidence of altered neurobehavioral outcomes by occupational exposure to vanadium. PMID:23500660

Bronchial dysplasia induced by radiation in miners exposed to 222Rn progeny.

PubMed Central

Michaylov, M A; Pressyanov, D S; Kalinov, K B

1995-01-01

OBJECTIVES--To investigate whether sputum cytology can be used to monitor epithelial cell changes in groups at high risk of lung cancer from exposure to radiation. METHODS--Dysplasia of bronchial cells was investigated by means of sputum cytology in a group of 434 underground miners. 100 of them were not exposed, and 334 were exposed to 222Rn progeny at cumulative exposures < 450 working level months. RESULTS--The frequency of dysplasia in the exposed group was significantly higher than that in the not exposed group (P < 0.0001), and an exposure-response relation was found. This relation was different for smokers and non-smokers. CONCLUSIONS--Possibly the frequencies of dysplasia could be used to assess past exposures of groups of miners. This approach could be applied to cases where data on radiation monitoring are not available or are very scarce. Images p82-a PMID:7757171

Micronucleated Erythrocytes in Peripheral Blood from Neonate Rats Exposed by Breastfeeding to Cyclophosphamide, Colchicine, or Cytosine-Arabinoside.

PubMed

Gómez-Meda, Belinda C; Bañales-Martínez, Luis R; Zamora-Perez, Ana L; Lemus-Varela, María de Lourdes; Trujillo, Xóchitl; Sánchez-Parada, María G; Torres-Mendoza, Blanca M; Armendáriz-Borunda, Juan; Zúñiga-González, Guillermo M

2016-01-01

Genotoxic exposure to chemical substances is common, and nursing mothers could transmit harmful substances or their metabolites to their offspring through breast milk. We explored the possibility of determining genotoxic effects in the erythrocytes of breastfeeding rat pups whose mothers received a genotoxic compound while nursing. Ten groups of female rats and five pups per dam were studied. The control group received sterile water, and the experimental groups received one of three different doses of cyclophosphamide, colchicine, or cytosine-arabinoside. Blood smears were prepared from samples taken from each dam and pup every 24 h for six days. There were increased numbers of micronucleated erythrocytes (MNEs) and micronucleated polychromatic erythrocytes (MNPCEs) in the samples from pups in the experimental groups ( P < 0.02) and increased MNPCE frequencies in the samples from the dams ( P < 0.05). These results demonstrate the vertical transmission of the genotoxic effect of the compounds tested. In conclusion, assessing MNEs in breastfeeding neonate rats to assess DNA damage may be a useful approach for identifying genotoxic compounds and/or cytotoxic effects. This strategy could help in screening for therapeutic approaches that are genotoxic during the lactation stage and these assessments might also be helpful for developing preventive strategies to counteract harmful effects.

Micronucleated Erythrocytes in Peripheral Blood from Neonate Rats Exposed by Breastfeeding to Cyclophosphamide, Colchicine, or Cytosine-Arabinoside

PubMed Central

Bañales-Martínez, Luis R.; Lemus-Varela, María de Lourdes; Trujillo, Xóchitl; Sánchez-Parada, María G.; Armendáriz-Borunda, Juan; Zúñiga-González, Guillermo M.

2016-01-01

Genotoxic exposure to chemical substances is common, and nursing mothers could transmit harmful substances or their metabolites to their offspring through breast milk. We explored the possibility of determining genotoxic effects in the erythrocytes of breastfeeding rat pups whose mothers received a genotoxic compound while nursing. Ten groups of female rats and five pups per dam were studied. The control group received sterile water, and the experimental groups received one of three different doses of cyclophosphamide, colchicine, or cytosine-arabinoside. Blood smears were prepared from samples taken from each dam and pup every 24 h for six days. There were increased numbers of micronucleated erythrocytes (MNEs) and micronucleated polychromatic erythrocytes (MNPCEs) in the samples from pups in the experimental groups (P < 0.02) and increased MNPCE frequencies in the samples from the dams (P < 0.05). These results demonstrate the vertical transmission of the genotoxic effect of the compounds tested. In conclusion, assessing MNEs in breastfeeding neonate rats to assess DNA damage may be a useful approach for identifying genotoxic compounds and/or cytotoxic effects. This strategy could help in screening for therapeutic approaches that are genotoxic during the lactation stage and these assessments might also be helpful for developing preventive strategies to counteract harmful effects. PMID:28018917

From Threat to Relief: Expressing Prejudice toward Atheists as a Self-Regulatory Strategy Protecting the Religious Orthodox from Threat

PubMed Central

Kossowska, Małgorzata; Szwed, Paulina; Czernatowicz-Kukuczka, Aneta; Sekerdej, Maciek; Wyczesany, Miroslaw

2017-01-01

We claim that religious orthodoxy is related to prejudice toward groups that violate important values, i.e., atheists. Moreover, we suggest that expressing prejudice may efficiently reduce the threat posed by this particular group among people who hold high levels, but not low levels, of orthodox belief. We tested these assumptions in an experimental study in which, after being exposed to atheistic worldviews (value-threat manipulation), high and low orthodox participants were allowed (experimental condition) or not (control condition) to express prejudice toward atheists. Threat was operationalized by cardiovascular reactivity, i.e., heart rate (HR); the higher the HR index, the higher the threat. The results found that people who hold high (vs. low) levels of orthodox belief responded with increased HR after the threat manipulation. However, we observed decreased HR after the expression of prejudice toward atheists among highly orthodox participants compared to the control condition. We did not find this effect among people holding low levels of orthodox belief. Thus, we conclude that expressing prejudice toward this particular group may be an efficient strategy to cope with the threat posed by this group for highly orthodox people. The results are discussed in light of previous findings on religious beliefs and the self-regulatory function of prejudice. PMID:28611715

A plausible radiobiological model of cardiovascular disease at low or fractionated doses

NASA Astrophysics Data System (ADS)

Little, Mark; Vandoolaeghe, Wendy; Gola, Anna; Tzoulaki, Ioanna

Atherosclerosis is the main cause of coronary heart disease and stroke, the two major causes of death in developed society. There is emerging evidence of excess risk of cardiovascular disease at low radiation doses in various occupationally-exposed groups receiving small daily radia-tion doses. Assuming that they are causal, the mechanisms for effects of chronic fractionated radiation exposures on cardiovascular disease are unclear. We outline a spatial reaction-diffusion model for atherosclerosis, and perform stability analysis, based wherever possible on human data. We show that a predicted consequence of multiple small radiation doses is to cause mean chemo-attractant (MCP-1) concentration to increase linearly with cumulative dose. The main driver for the increase in MCP-1 is monocyte death, and consequent reduction in MCP-1 degradation. The radiation-induced risks predicted by the model are quantitatively consistent with those observed in a number of occupationally-exposed groups. The changes in equilibrium MCP-1 concentrations with low density lipoprotein cholesterol concentration are also consistent with experimental and epidemiologic data. This proposed mechanism would be experimentally testable. If true, it also has substantive implications for radiological protection, which at present does not take cardiovascular disease into account. The Japanese A-bomb survivor data implies that cardiovascular disease and can-cer mortality contribute similarly to radiogenic risk. The major uncertainty in assessing the low-dose risk of cardiovascular disease is the shape of the dose response relationship, which is unclear in the Japanese data. The analysis of the present paper suggests that linear extrapo-lation would be appropriate for this endpoint.

Social Stress Increases Cortisol and Hampers Attention in Adolescents with Excess Weight

PubMed Central

Verdejo-Garcia, Antonio; Moreno-Padilla, Maria; Garcia-Rios, M. Carmen; Lopez-Torrecillas, Francisca; Delgado-Rico, Elena; Schmidt-Rio-Valle, Jacqueline; Fernandez-Serrano, Maria J.

2015-01-01

Objective To experimentally examine if adolescents with excess weight are more sensitive to social stress and hence more sensitive to harmful effects of stress in cognition. Design and Methods We conducted an experimental study in 84 adolescents aged 12 to 18 years old classified in two groups based on age adjusted Body Mass Index percentile: Normal weight (n=42) and Excess weight (n=42). Both groups were exposed to social stress as induced by the virtual reality version of the Trier Social Stress Task --participants were requested to give a public speech about positive and negative aspects of their personalities in front of a virtual audience. The outcome measures were salivary cortisol levels and performance in cognitive tests before and after the social stressor. Cognitive tests included the CANTAB Rapid Visual Processing Test (measuring attention response latency and discriminability) and the Iowa Gambling Task (measuring decision-making). Results Adolescents with excess weight compared to healthy weight controls displayed increased cortisol response and less improvement of attentional performance after the social stressor. Decision-making performance decreased after the social stressor in both groups. Conclusion Adolescents who are overweight or obese have increased sensitivity to social stress, which detrimentally impacts attentional skills. PMID:25898204

Assessing attitudes toward computers and the use of Internet resources among undergraduate microbiology students

NASA Astrophysics Data System (ADS)

Anderson, Delia Marie Castro

Computer literacy and use have become commonplace in our colleges and universities. In an environment that demands the use of technology, educators should be knowledgeable of the components that make up the overall computer attitude of students and be willing to investigate the processes and techniques of effective teaching and learning that can take place with computer technology. The purpose of this study is two fold. First, it investigates the relationship between computer attitudes and gender, ethnicity, and computer experience. Second, it addresses the question of whether, and to what extent, students' attitudes toward computers change over a 16 week period in an undergraduate microbiology course that supplements the traditional lecture with computer-driven assignments. Multiple regression analyses, using data from the Computer Attitudes Scale (Loyd & Loyd, 1985), showed that, in the experimental group, no significant relationships were found between computer anxiety and gender or ethnicity or between computer confidence and gender or ethnicity. However, students who used computers the longest (p = .001) and who were self-taught (p = .046) had the lowest computer anxiety levels. Likewise students who used computers the longest (p = .001) and who were self-taught (p = .041) had the highest confidence levels. No significant relationships between computer liking, usefulness, or the use of Internet resources and gender, ethnicity, or computer experience were found. Dependent T-tests were performed to determine whether computer attitude scores (pretest and posttest) increased over a 16-week period for students who had been exposed to computer-driven assignments and other Internet resources. Results showed that students in the experimental group were less anxious about working with computers and considered computers to be more useful. In the control group, no significant changes in computer anxiety, confidence, liking, or usefulness were noted. Overall, students in the experimental group, who responded to the use of Internet Resources Survey, were positive (mean of 3.4 on the 4-point scale) toward their use of Internet resources which included the online courseware developed by the researcher. Findings from this study suggest that (1) the digital divide with respect to gender and ethnicity may be narrowing, and (2) students who are exposed to a course that augments computer-driven courseware with traditional teaching methods appear to have less anxiety, have a clearer perception of computer usefulness, and feel that online resources enhance their learning.

Methylation of inorganic arsenic in different mammalian species and population groups.

PubMed

Vahter, M

1999-01-01

Thousands of people in different parts of the world are exposed to arsenic via drinking water or contaminated soil or food. The high general toxic of arsenic has been known for centuries, and research during the last decades has shown that arsenic is a potent human carcinogen. However, most experimental cancer studies have failed to demonstrate carcinogenicity in experimental animals, indicating marked variation in sensitivity towards arsenic toxicity between species. It has also been suggested that there is a variation in susceptibility among human individuals. One reason for such variability in toxic response may be variation in metabolism. Inorganic arsenic is methylated in humans as well as animals and micro-organisms, but there are considerable differences between species and individuals. In many, but not all, mammalian species, inorganic arsenic is methylated to methylarsonic acid (MMA) and dimethylarsinic acid (DMA), which are more rapidly excreted in urine than is the inorganic arsenic, especially the trivalent form (AsIII, arsenite) which is highly reactive with tissue components. Absorbed arsenate (AsV) is reduced to trivalent arsenic (AsIII) before the methyl groups are attached. It has been estimated that as much as 50-70% of absorbed AsV is rapidly reduced to AsIII, a reaction which seems to be common for most species. In most experimental animal species, DMA is the main metabolite excreted in urine. Compared to human subjects, very little MMA is produced. However, the rate of methylation varies considerably between species, and several species, e.g. the marmoset monkey and the chimpanzee have been shown not to methylate inorganic arsenic at all. In addition, the marmoset monkey accumulates arsenic in the liver. The rat, on the other hand, has an efficient methylation of arsenic but the formed DMA is to a large extent accumulated in the red blood cells. As a result, the rat shows a low rate of excretion of arsenic. In both human subjects and rodents exposed to DMA, about 5% of the dose is excreted in the urine as trimethylarsine oxide. It is obvious from studies on human volunteers exposed to specified doses of inorganic arsenic that the rate of excretion increases with the methylation efficiency, and there are large inter-individual variations in the methylation of arsenic. Recent studies on people exposed to arsenic via drinking water in northern Argentina have shown unusually low urinary excretion of MMA. Furthermore, children had a lower degree of methylation of arsenic than adults. Some studies indicate a lower degree of arsenic methylation in men than in women, especially during pregnancy. Whether the observed differences in methylation of arsenic are associated with variations in the susceptibility of arsenic remains to be investigated.

The scent of stress: environmental challenge in the peripartum environment of mice affects emotional behaviours of the adult offspring in a sex-specific manner.

PubMed

Lerch, S; Dormann, C; Brandwein, C; Gass, P; Chourbaji, S

2016-06-01

Early adverse experiences are known to influence the risk of developing psychiatric disorders later. To shed further light on the development of laboratory mice, we systematically examined the influence of a prenatal or postnatal olfactory stressor, namely unfamiliar male mouse faeces, presented to pregnant or nursing mouse dams. Maternal and offspring behaviours were then examined. Maternal behaviours relative to controls revealed changes in nest building by the pregnant dams exposed to the unfamiliar faeces. There were no differences among groups on pup retrieval or exploration by the dams. Behavioural phenotyping of male and female offspring as adults included measures of exploration, anxiety, social and depressive-like behaviours. Additionally, serum corticosterone was assessed as a marker of physiological stress response. Group differences were dependent on the sex of the adult offspring. Males raised by dams that were stressed during pregnancy presented elevated emotionality as indicated by increased numbers of faecal boluses in the open field paradigm. Consistent with the effects of prenatal stress on the males only the prenatally stressed females had higher body weights than their respective controls. Indeed, males in both experimental groups had higher circulating corticosterone levels. By contrast, female offspring of dams exposed to the olfactory stressor after parturition were more anxious in the O-maze as indicated by increased latencies in entering the exposed areas of the maze. These findings emphasize the necessity for researchers to consider the pre- and postnatal environments, even of mice with almost identical genetic backgrounds, in designing experiments and interpreting their data. © The Author(s) 2015.

Morphological and behavioral responses of zebrafish after 24h of ketamine embryonic exposure.

PubMed

Félix, Luís M; Serafim, Cindy; Martins, Maria J; Valentim, Ana M; Antunes, Luís M; Matos, Manuela; Coimbra, Ana M

2017-04-15

Ketamine, one anesthetic used as an illicit drug, has been detected both in freshwater and marine ecosystems. However, knowledge of its impact on aquatic life is still limited. This study aimed to test its effects in zebrafish embryos by analyzing its time- and dose-dependent developmental toxicity and long-term behavioral changes. The 24h-LC 50 was calculated from percent survival using probit analysis. Based on the 24h-LC 50 (94.4mgL -1 ), embryos (2hour post-fertilization - hpf) were divided into four groups, including control, and exposed for 24h to ketamine concentrations of 50, 70 or 90mgL -1 . Developmental parameters were evaluated on the course of the experimental period, and anatomical abnormalities and locomotor deficits were analyzed at 144hpf. Although the portion of ketamine transferred into the embryo was higher in the lowest exposed group (about 0.056±0.020pmol per embryo), the results showed that endpoints such as increased mortality, edema, heart rate alterations, malformation and abnormal growth rates were significantly affected. At 144hpf, the developmental abnormalities included thoracic and trunk abnormalities in the groups exposed to 70 and 90mgL -1 . Defects in cartilage (alcian blue) and bone (calcein) elements also corroborated the craniofacial anomalies observed. A significant up-regulation of the development-related gene nog3 was detected by qRT-PCR at 8 hpf. Early exposure to ketamine also resulted in long-term behavioral changes, such as an increase in thigmotaxis and disruption of avoidance behavior at 144 hpf. Altogether, this study provides new evidence on the ketamine teratogenic potential, indicating a possible pharmacological impact of ketamine in aquatic environments. Copyright © 2017 Elsevier Inc. All rights reserved.

Adolescent nicotine exposure disrupts context conditioning in adulthood in rats.

PubMed

Spaeth, Andrea M; Barnet, Robert C; Hunt, Pamela S; Burk, Joshua A

2010-10-01

Despite the prevalence of smoking among adolescents, few studies have assessed the effects of adolescent nicotine exposure on learning in adulthood. In particular, it remains unclear whether adolescent nicotine exposure has effects on hippocampus-dependent learning that persist into adulthood. The present experiment examined whether there were effects of adolescent nicotine exposure on context conditioning, a form of learning dependent on the integrity of the hippocampus, when tested during adulthood. Rats were exposed to nicotine during adolescence (postnatal days [PD] 28-42) via osmotic minipump (0, 3.0 or 6.0mg/kg/day). Context conditioning occurred in early adulthood (PD 65-70). Animals were exposed to an experimental context and were given 10 unsignaled footshocks or no shock. Additional groups were included to test the effects of adolescent nicotine on delay conditioning, a form of learning that is not dependent upon the hippocampus. Conditioning was assessed using a lick suppression paradigm. For animals in the context conditioning groups, adolescent nicotine resulted in significantly less suppression of drinking in the presence of context cues compared with vehicle-pretreated animals. For animals in the delay conditioning groups, there was a trend for adolescent nicotine (3.0mg/kg/day) to suppress drinking compared to vehicle-pretreated animals. There were no differences in extinction of contextual fear or cued fear between rats previously exposed to vehicle or nicotine. The data indicate that adolescent nicotine administration impairs context conditioning when animals are trained and tested as adults. The present data suggest that adolescent nicotine exposure may disrupt hippocampus-dependent learning when animals are tested during adulthood. (c) 2010 Elsevier Inc. All rights reserved.

Ameliorating Role of Lycopene, Tomato Puree, and Spirulina + Tomato Puree on the Hematology of Fluoride-Exposed Swiss Albino Mice.

PubMed

Sharma, Shweta; Parashar, Puneet; Sharma, Subhasini; Sharma, Kanta Prasad

2018-01-16

Plant species rich in antioxidants (vitamins, flavonoids, lignans, and carotenoids) have been explored for complementary therapy of chronic diseases (cancers, coronary heart disease) and mitigation of pollutant toxicity. This article investigates their ameliorative role on selective hematological and serum biochemical parameters in fluoride-exposed (190 mg/kg body weight) Swiss albino mice pretreated with the antioxidant-rich diet supplements tomato puree (with and without peels), spirulina (cyanobacteria), and lycopene (present in tomato) for 45 days prior to entry into experimental protocol. Compared with standard feed control, diet-modulated controls had more hairy and lustrous white fur, hemodilution, increase in platelet counts (2- to 5-fold), red blood cell (RBC) size (11%-14%), mean corpuscular hemoglobin (Hb) concentration (MCHC; 5%-14%), and serum albumin (23%-27%). Fluoride-exposed mice reared on standard feed had less hairy, pale white, lusterless fur and black nails, reduction in RBC and white blood cell (WBC) counts and Hb content, and morphological abnormalities in RBCs (poikilocytosis). By contrast, fur quality of fluoride-treated diet-modulated groups was similar to standard feed control; counts and morphology of their RBCs and Hb content similar to the respective controls, and increase in WBC counts greater than controls. In comparison to the fluoride-treated standard feed group, platelet counts were higher in the treated mice of the diet-modulated groups. This study thus revealed the hemoprotective role of diet supplements in fluoride-treated mice. Considering the prevalence of fluoride-induced chronic toxicity in developing countries, our findings have relevance in minimizing hematological disorders among people residing in the fluoride-affected areas, because indigenously cultivated low-price tomato fruits are easily available for consumption.

[Effect of diisobutyl phthalate on learning and memory behavior and apoptosis of hippocampus cells in mice].

PubMed

Ma, Ning; Liu, Shan; Gao, Peng; Cao, Pei; Xu, Haibin

2013-01-01

To give the original research of diisobutyl phthalate (DiBP) on learning and memory behavior, determine whether it can through blood-brain barrier and effect apoptosis of hippocampus cells in mice. Accommodating 60 Kunming mice to the animal house for 3 days, then dividing the mice into 5 groups according to their weights. That is, one control group and four experimental groups (I group, 50 mg/kg BW. II group, 250mg/kg BW. III group, 500 mg/kg BW. IV group, 1000 mg/kg BW). The mice were fed with the corn oil in control group, and the other groups were fed with the related dose of diisobutyl phthalate mixture by gavages last for 8 weeks. At the end of experimental time, passive avoidance response was examined, then all of mice were killed, and choosed the brain tissues to test the DiBP content and apoptosis rate of hippocampal cells and hippocampal ultrastructural alterations on electron microscopy. In the passive avoidance response test, the exposed animals of IV group showed learning impairment as compared to unexposed mice (P < 0.05). DiBP was detected in III group and IV group, the mean content of them were (1.27 +/- 0.56) and (1.96 +/- 0.42) microg/g. The apoptosis rate of hippocampal cells (IV group vs control group) increase significantly (P < 0.05). Hippocampal ultrastructural were damaged in all dose-groups. As a result, in the experiments, exposure to DiBP could exert passive avoidance neurobehavioral effects. DiBP could through blood-brain barrier after oral intake, and disordered the way of apoptosis of hippocampal cells, and morphologic change of mitochondria mybe is the main reason of changes of neuron apoptosis.

Early exposure to noise followed by predator stress in adulthood impairs the rat's re-learning flexibility in Radial Arm Water Maze.

PubMed

Jauregui-Huerta, Fernando; Ruvalcaba-Delgadillo, Yaveth; Garcia-Estrada, Joaquin; Feria-Velasco, Alfredo; Ramos-Zuñiga, Rodrigo; Gonzalez-Perez, Oscar; Luquin, Sonia

2010-01-01

This study investigated the cognitive effect of chronic exposure to environmental noise on RAWM performance of juvenile rats, and the ability of adult rats exposed to a novel acute stress to perform in the RAWM as a function of whether or not they were exposed to environmental noise as juveniles. We examined the consequences of exposure to noise during the juvenile-early periadolescent period on adulthood stress response by assessing cognitive performance in the RAWM. Male rats were exposed to environmental noise during the childhood-prepubescent period (21-35 PND), and their RAWM performance was tested at the end of the exposure to noise, and then again two months later when they had to cope with a new stressful event. RAWM execution included a 3-day training phase and a reversal learning phase on day 4. Escape latency, reference memory errors and working memory errors were compared between experimental and control groups. In addition, body weight gain and serum corticosterone levels were evaluated. Stressed rats demonstrated spatial impairment, as evidenced by poor execution on day 4. This effect was significantly noticeable in the doubly stressed group. Noise annoyance was evidenced by reduced body weight gain and increased serum corticosterone levels. Our results suggest that environmental noise may produce potent stress-like effects in developing subjects that can persist into adulthood, affecting spatial learning abilities. This cognitive impairment may restrict the subject's ability to learn under a new spatial configuration.

Autoshaping, random control, and omission training in the rat1

PubMed Central

Locurto, Charles; Terrace, H. S.; Gibbon, John

1976-01-01

The role of the stimulus-reinforcer contingency in the development and maintenance of lever contact responding was studied in hooded rats. In Experiment I, three groups of experimentally naive rats were trained either on autoshaping, omission training, or a random-control procedure. Subjects trained by the autoshaping procedure responded more consistently than did either random-control or omission-trained subjects. The probability of at least one lever contact per trial was slightly higher in subjects trained by the omission procedure than by the random-control procedure. However, these differences were not maintained during extended training, nor were they evident in total lever-contact frequencies. When omission and random-control subjects were switched to the autoshaping condition, lever contacts increased in all animals, but a pronounced retardation was observed in omission subjects relative to the random-control subjects. In addition, subjects originally exposed to the random-control procedure, and later switched to autoshaping, acquired more rapidly than naive subjects that were exposed only on the autoshaping procedure. In Experiment II, subjects originally trained by an autoshaping procedure were exposed either to an omission, a random-control, or an extinction procedure. No differences were observed among the groups either in the rate at which lever contacts decreased or in the frequency of lever contacts at the end of training. These data implicate prior experience in the interpretation of omission-training effects and suggest limitations in the influence of stimulus-reinforcer relations in autoshaping. PMID:16811960

Autoshaping, random control, and omission training in the rat.

PubMed

Locurto, C; Terrace, H S; Gibbon, J

1976-11-01

The role of the stimulus-reinforcer contingency in the development and maintenance of lever contact responding was studied in hooded rats. In Experiment I, three groups of experimentally naive rats were trained either on autoshaping, omission training, or a random-control procedure. Subjects trained by the autoshaping procedure responded more consistently than did either random-control or omission-trained subjects. The probability of at least one lever contact per trial was slightly higher in subjects trained by the omission procedure than by the random-control procedure. However, these differences were not maintained during extended training, nor were they evident in total lever-contact frequencies. When omission and random-control subjects were switched to the autoshaping condition, lever contacts increased in all animals, but a pronounced retardation was observed in omission subjects relative to the random-control subjects. In addition, subjects originally exposed to the random-control procedure, and later switched to autoshaping, acquired more rapidly than naive subjects that were exposed only on the autoshaping procedure. In Experiment II, subjects originally trained by an autoshaping procedure were exposed either to an omission, a random-control, or an extinction procedure. No differences were observed among the groups either in the rate at which lever contacts decreased or in the frequency of lever contacts at the end of training. These data implicate prior experience in the interpretation of omission-training effects and suggest limitations in the influence of stimulus-reinforcer relations in autoshaping.

Myelin protein zero and its antibody in serum as biomarkers of n-hexane-induced peripheral neuropathy and neurotoxicity effects.

PubMed

Jia, Xiaowei; Liu, Qingjun; Zhang, Yanshu; Dai, Yufei; Duan, Huawei; Bin, Ping; Niu, Yong; Liu, Jie; Zhong, Liuzhen; Guo, Jisheng; Liu, Xiaofeng; Zheng, Yuxin

2014-01-01

Chronic exposure to n-hexane can lead to peripheral neuropathy that no effective treatment regimen could be applied presently. This study investigated whether myelin protein zero (P0) protein and its antibody could be used to distinguish n-hexane intoxication and protect workers from peripheral neuropathy. We compared P0 protein and its antibody among three levels of n-hexane-exposed groups, which included 18 patients with n-hexane-induced peripheral neuropathy as case group, 120 n-hexane-exposed workers as n-hexaneexposed control group, and 147 non-hexane-exposed participants used as control group. ELISA method was applied to detect P0 protein and its antibody. P0 protein in serum was significantly higher in the case group and n-hexane-exposed control group in comparison with the control group (P < 0.01). Compared with the n-hexane-exposed control group, the case group also had significant increase of P0 protein (P < 0.01). After 6 months therapy, P0 protein was observed to decrease significantly in the case group (P < 0.01). The P0 antibody in serum was significantly higher in the n-hexane-exposed control group than in the control group (P < 0.01), but not significantly different between cases and controls. P0 antibodies in serum may be a short-term effect biomarker for n-hexane exposure. P0 protein in serum may be an early effective biomarker for peripheral nerve neuropathy and its biological limit value needs investigation in the future study.

[Effects on serum myelin proteins of n-hexane exposure].

PubMed

Yi, Juan; Zhou, Wei; He, Jia-xi; Liu, Qing-jun; Huang, Xian-qing

2011-02-01

Exploring the effects of n-hexane on expression of serum myelin proteins in occupational exposure workers, and finding the early biomarker of n-hexane exposure. In the study, 373 subjects were recruited, 269 exposure workers (work experience of more than1 year) and 104 non-exposure workers were selected. Firstly examined the level of urinary 2,5-hexanedione in the two groups, based on urinary 2,5-hexanedione biological limit value (4 mg/L), the exposed group was divided into high-exposed group and low-exposed group. And then collected blood samples and extracted serum. Human peripheral myelin protein zero (P0) antibody (IgG, IgM) and human peripheral myelin protein two (P2) antibody (IgG, IgM) analysis was performed according to ELISA kit. The concentration of urinary 2,5-hexanedione in the exposed group was (3.10 ± 1.35) mg/L. The level of P0 antibody (IgG, IgM) and P2 antibody (IgG, IgM) in the high-exposed group and low-exposed group were both higher than that in the controls (P < 0.01). P0 antibody and P2 antibody could be used as the early biomarkers of n-hexane exposure, which not only evaluate the occupational hazards in the early, but also provide the policy maker with scientific evidence.

Bioceramic/poly (glycolic)-poly (lactic acid) composite induces mineralized barrier after direct capping of rat tooth pulp tissue.

PubMed

Gala-Garcia, Alfonso; Teixeira, Karina Imaculada Rosa; Wykrota, Francisco Henrique Lana; Sinisterra, Rubén Dario; Cortés, Maria Esperanza

2010-01-01

The aim of this study was to observe the histopathological pulp response following direct pulp capping of mechanically exposed teeth in rats with a composite of beta-tricalcium phosphate-hydroxyapatite bioceramic (BC) and poly (glycolic)-poly (lactic acid) (PLGA) material or a calcium hydroxide [Ca(OH)2] material, compared to BC alone and a negative control of water. Pulp of the maxillary molars was exposed, followed by capping with the experimental material. The pulpal tissue response was assessed post-operatively at 1, 7, 14 and 30 d, followed by histological analysis. The Ca(OH)2 group exhibited severe acute inflammatory cell infiltration at day 14. However after 30 d, a new hard tissue with macro porous obliteration of the pulp chamber and a characteristic necrotic area had appeared. BC and Ca(OH)2 capping were associated with moderate inflammation and dentinal bridge similar. Meanwhile, in the BC/PLGA composite group, there was moderate inflammatory infiltrate and formation of a dense and complete dentinal bridge. In conclusion, the BC/PLGA composite material showed a large zone of tertiary dentin, and effectively reorganized the dentin-pulp complex.

Protective Effects of Vitamin E Consumption against 3MT Electromagnetic Field Effects on Oxidative Parameters in Substantia Nigra in Rats

PubMed Central

Ghanbari, Ahmad Ali; Shabani, Kobra; Mohammad Nejad, Daryoush

2016-01-01

Introduction: Electromagnetic fields (EMFs) can influence the biological system by the formation of free radicals in cells. The EMFs are able to deteriorate defense system against free radicals that leads to oxidative stress (OS). Lipid peroxidation process (LPO) is an index of oxidative stress, and the Malandialdehyde (MDA) is the final product of LPO. Vitamin E is the most important antioxidant which inhibits the LPO process. The aim of this study was to evaluate the effects of 3MT EMF exposure on oxidative stress parameters in substantia nigra and the role of vitamin E in reducing oxidative stress and preventing of LPO process. Methods: 40 male Wistar rats were randomly divided into 4 groups: 1) Control group: received standard food without exposure to EMF and without consumption of vitamin E, 2) Experimental group 1: was exposed to EMF (3MT) 4 h/day for 50 days, 3) The experimental group 2: received 200 mg/kg vitamin E with gavage every day and also was exposed to EMF (3MT) 4 h/day for 50 days, 4) Sham group: received water with gavage for 50 days. Results: A significant increase in MDA levels and Glutation peroxidase (GSH-Px) activity of the substantia nigra following 50 days exposure to EMF was detected, but the superoxide dismutase (SOD) activity was decreased. Exposure did not change total antioxidant capacity (TAC) levels in plasma. Vitamin E treatment significantly prevented the increase of the MDA levels and GSHPx activity and also prevented the decrease of SOD activity in tissue but did not alter TAC levels. The GSH-Px activity increased because the duration and intensity of exposure were not enough to decrease it. Conclusion: We demonstrated two important findings; that 50 days exposure to 3 MT electromagnetic field caused oxidative stress by increasing the levels of MDA, and decreasing SOD activity in the substantia nigra; and that treatment with the vitamin E significantly prevented the oxidative stress and lipid peroxidation. PMID:27872692

Grape juice concentrate (G8000(®) ) intake mitigates testicular morphological and ultrastructural damage following cadmium intoxication.

PubMed

Lamas, Celina A; Gollücke, Andrea P B; Dolder, Heidi

2015-10-01

Cadmium is a well-known testicular toxicant, and parts of the world population are exposed chronically by inhalation or by food and water intake. Grape products have been highlighted as important sources of bioactive compounds, having anti-inflammatory, anti-oxidant and metal chelating properties. Since maintenance of tissue morphology is essential for testicular sperm development and hence male fertility, we analysed the protective effect of grape juice concentrate (GJC) (G8000(®) ) consumption on testicular morphology in rats exposed to cadmium. Thus, four groups of male Wistar rats (n = 6 per group), 50 days old, ingested either water or G8000(®) (2 g/kg/day) until they had completed one spermatogenic cycle in adult life (136 days old). Cadmium (1.2 mg / kg) was injected intraperitoneally when the animals were 80 days old into one of the water and one of the G8000 groups; intraperitoneal saline was used as a control in the other two groups. Animals anaesthetised and exsanguinated at 136 days and then perfused with Karnovsky's fixative and then the testes were collected for morphological analysis. We describe evident disruption of testicular morphology by cadmium, with alteration in tissue component proportions, reduced Leydig cells volume and initial signs of an inflammatory process. Ultrastructural analysis showed greater damage, suggesting spermatogenesis disruption. G8000(®) ingestion allowed tissue architecture to be re-established, as was corroborated by our stereological and morphometric findings. Animals from the group where G8000(®) had been administered together with cadmium revealed a significant reduction in macrophages and blood vessel volume, suggesting diminished inflammation, when compared to animals that received only cadmium. Moreover, smaller number of ultrastructural alterations was noted, revealing fewer areas of degeneration and disorganized interstitium. In conclusion, our results demonstrate that GJC consumption prevented the spermatogenic disruption promoted by cadmium, and thus could be a promising form of therapy against male infertility. © 2015 The Authors. International Journal of Experimental Pathology © 2015 International Journal of Experimental Pathology.

Predicting the effectiveness of road safety campaigns through alternative research designs.

PubMed

Adamos, Giannis; Nathanail, Eftihia

2016-12-01

A large number of road safety communication campaigns have been designed and implemented in the recent years; however their explicit impact on driving behavior and road accident rates has been estimated in a rather low proportion. Based on the findings of the evaluation of three road safety communication campaigns addressing the issues of drinking and driving, seat belt usage, and driving fatigue, this paper applies different types of research designs (i.e., experimental, quasi-experimental, and non-experimental designs), when estimating the effectiveness of road safety campaigns, implements a cross-design assessment, and conducts a cross-campaign evaluation. An integrated evaluation plan was developed, taking into account the structure of evaluation questions, the definition of measurable variables, the separation of the target audience into intervention (exposed to the campaign) and control (not exposed to the campaign) groups, the selection of alternative research designs, and the appropriate data collection methods and techniques. Evaluating the implementation of different research designs in estimating the effectiveness of road safety campaigns, results showed that the separate pre-post samples design demonstrated better predictability than other designs, especially in data obtained from the intervention group after the realization of the campaign. The more constructs that were added to the independent variables, the higher the values of the predictability were. The construct that most affects behavior is intention, whereas the rest of the constructs have a lower impact on behavior. This is particularly significant in the Health Belief Model (HBM). On the other hand, behavioral beliefs, normative beliefs, and descriptive norms, are significant parameters for predicting intention according to the Theory of Planned Behavior (TPB). The theoretical and applied implications of alternative research designs and their applicability in the evaluation of road safety campaigns are provided by this study. Copyright © 2016 Elsevier Ltd and National Safety Council. All rights reserved.

Group size adjustment to ecological demand in a cooperative breeder.

PubMed

Zöttl, Markus; Frommen, Joachim G; Taborsky, Michael

2013-04-07

Environmental factors can determine which group size will maximize the fitness of group members. This is particularly important in cooperative breeders, where group members often serve different purposes. Experimental studies are yet lacking to check whether ecologically mediated need for help will change the propensity of dominant group members to accept immigrants. Here, we manipulated the perceived risk of predation for dominant breeders of the cooperatively breeding cichlid fish Neolamprologus pulcher to test their response to unrelated and previously unknown immigrants. Potential immigrants were more readily accepted if groups were exposed to fish predators or egg predators than to herbivorous fish or control situations lacking predation risk. Our data are consistent with both risk dilution and helping effects. Egg predators were presented before spawning, which might suggest that the fish adjust acceptance rates also to a potential future threat. Dominant group members of N. pulcher apparently consider both present and future need of help based on ecological demand. This suggests that acceptance of immigrants and, more generally, tolerance of group members on demand could be a widespread response to ecological conditions in cooperatively breeding animals.

Influence of 1800 MHz GSM-like electromagnetic radiation exposure on fracture healing.

PubMed

Aslan, Ahmet; Kırdemır, Vecihi; Kocak, Ahmet; Atay, Tolga; Baydar, Metin Lütfi; Özerdemoglu, Remzi Arif; Aydogan, Nevres Hürriyet

2014-02-01

In this study, we aimed to investigate whether 1800 MHz frequency electromagnetic radiation (EMR) has an effect on bone healing. A total of 30 Wistar albino rats were divided into two equal groups. Fractures were created in the right tibias of all rats; next, intramedullary fixations with K-wire were performed. A control group (Group I) was kept under the same experimental conditions except without EMR exposure. Rats in Group II were exposed to an 1800 MHz frequency EMR for 30 min a day for 5 days a week. Next, radiological, mechanical, and histological examinations were performed to evaluate tibial fracture healing. Radiological, histological and mechanical scores were not significantly different between groups (respectively, p = 0.114, p = 0.184 and p = 0.083), and all of these scores were lower than those of the controls. EMR at 1800 MHz frequency emitted from cellular phones has no effect on bone fracture healing. Copyright © 2014 IMSS. Published by Elsevier Inc. All rights reserved.

Fetal Cardiac Impairment in Nitrofen-Induced Congenital Diaphragmatic Hernia: Postmortem Microcomputed Tomography Imaging Study.

PubMed

Pelizzo, Gloria; Calcaterra, Valeria; Lombardi, Claudio; Bussani, Rossana; Zambelli, Vanessa; De Silvestri, Annalisa; Custrin, Ana; Belgrano, Manuel; Zennaro, Floriana

2017-08-01

We assessed the post-mortem micro-CT utility to evaluate fetal cardiac impairment in nitrofen-induced congenital diaphragmatic hernia (CDH). At 9.5d postconception (dpc), pregnant rats were exposed to nitrofen. At +18 and +21dpc, fetuses were harvested by cesarean section. Postmortem micro-CT and autopsy were performed. Fetuses were assigned to three experimental groups: Control group (C), Nitrofen group (N, exposition to nitrofen without CDH), CDH group. Cardio-pulmonary indices were evaluated. An accurate morphological evaluation of the lung and heart was obtained. Early cardiac impairment was present in the N and CDH groups. At term pregnancy, an increased maximum diameter and decreased minimum diameter of the ventricles and increased interventricular septal thickness were noted in CDH. Histology showed a myocardial "disarray" and an high density of mitotic myocytes in CDH at midgestation. The potential utility of post-mortem fetal micro-CT examination in CDH was introduced. The results highlighted the presence of cardiac adaptation in affected fetuses.

Effect of gamma-ray irradiation on the unloaded animal model

NASA Astrophysics Data System (ADS)

Choi, Jong-Il; Yoon, Min-Chul; Sung, Nak-Yoon; Kim, Jae-Hun; Jong Lee, Yun; Lee, Ki-Soo; Choi, In-Ho; Nam, Gung Uk; Lee, Ju-Woon

During the space flight, human beings encountered the extreme conditions such as the cosmic ray irradiation and microgravity. There have been developed the animal models to simulate the microgravity condition in laboratory, but no study was carried out to investigate the combined effect of microgravity and exposure to irradiation. In this study, it was examined the effect of gamma irradiation on the suspension model. Rats were divided into four groups, Group I was loaded and not exposed to gamma irradiation, Group 2 was unloaded and not exposed, Group 3 was loaded and exposed to gamma irradiation at the dose of 50 mSV, and Group 4 was unloaded and exposed to gamma irradiation at the same dose. It was measured body, muscles and tissues weights and the biological analysis and the hematological response in blood samples were conducted. Anti-gravity tissue weight was only changed between loading and un-loading condition. However, there was no difference between irradiation exposed and not exposed unloaded groups. To know the difference of protein expression in anti-gravity tissues, 2 dimensional electrophoresis was performed. It has been found that the expression levels of several proteins were different by unloading condition and by irradiation exposed condition, respectively. These results provided the information on the combined effect of irradiation and microgravity to simulate space flight, and could be useful to search the candidate material for the countermeasure against space environment.

A chemical-biological similarity-based grouping of complex substances as a prototype approach for evaluating chemical alternatives.

PubMed

Grimm, Fabian A; Iwata, Yasuhiro; Sirenko, Oksana; Chappell, Grace A; Wright, Fred A; Reif, David M; Braisted, John; Gerhold, David L; Yeakley, Joanne M; Shepard, Peter; Seligmann, Bruce; Roy, Tim; Boogaard, Peter J; Ketelslegers, Hans B; Rohde, Arlean M; Rusyn, Ivan

2016-08-21

Comparative assessment of potential human health impacts is a critical step in evaluating both chemical alternatives and existing products on the market. Most alternatives assessments are conducted on a chemical-by-chemical basis and it is seldom acknowledged that humans are exposed to complex products, not individual substances. Indeed, substances of U nknown or V ariable composition, C omplex reaction products, and B iological materials (UVCBs) are ubiquitous in commerce yet they present a major challenge for registration and health assessments. Here, we present a comprehensive experimental and computational approach to categorize UVCBs according to global similarities in their bioactivity using a suite of in vitro models. We used petroleum substances, an important group of UVCBs which are grouped for regulatory approval and read-across primarily on physico-chemical properties and the manufacturing process, and only partially based on toxicity data, as a case study. We exposed induced pluripotent stem cell-derived cardiomyocytes and hepatocytes to DMSO-soluble extracts of 21 petroleum substances from five product groups. Concentration-response data from high-content imaging in cardiomyocytes and hepatocytes, as well as targeted high-throughput transcriptomic analysis of the hepatocytes, revealed distinct groups of petroleum substances. Data integration showed that bioactivity profiling affords clustering of petroleum substances in a manner similar to the manufacturing process-based categories. Moreover, we observed a high degree of correlation between bioactivity profiles and physico-chemical properties, as well as improved groupings when chemical and biological data were combined. Altogether, we demonstrate how novel in vitro screening approaches can be effectively utilized in combination with physico-chemical characteristics to group complex substances and enable read-across. This approach allows for rapid and scientifically-informed evaluation of health impacts of both existing substances and their chemical alternatives.

Tyrosine Mutation in AAV9 Capsid Improves Gene Transfer to the Mouse Lung.

PubMed

Martini, Sabrina V; Silva, Adriana L; Ferreira, Debora; Rabelo, Rafael; Ornellas, Felipe M; Gomes, Karina; Rocco, Patricia R M; Petrs-Silva, Hilda; Morales, Marcelo M

2016-01-01

Adeno-associated virus (AAV) vectors are being increasingly used as the vector of choice for in vivo gene delivery and gene therapy for many pulmonary diseases. Recently, it was shown that phosphorylation of surface-exposed tyrosine residues from AAV capsid targets the viral particles for ubiquitination and proteasome-mediated degradation, and mutations of these tyrosine residues lead to highly efficient vector transduction in vitro and in vivo in different organs. In this study, we evaluated the pulmonary transgene expression efficacy of AAV9 vectors containing point mutations in surface-exposed capsid tyrosine residues. Eighteen C57BL/6 mice were randomly assigned into three groups: (1) a control group (CTRL) animals underwent intratracheal (i.t.) instillation of saline, (2) the wild-type AAV9 group (WT-AAV9, 1010 vg), and (3) the tyrosine-mutant Y731F AAV9 group (M-AAV9, 1010 vg), which received (i.t.) self-complementary AAV9 vectors containing the DNA sequence of enhanced green fluorescence protein (eGFP). Four weeks after instillation, lung mechanics, morphometry, tissue cellularity, gene expression, inflammatory cytokines, and growth factor expression were analyzed. No significant differences were observed in lung mechanics and morphometry among the experimental groups. However, the number of polymorphonuclear cells was higher in the WT-AAV9 group than in the CTRL and M-AAV9 groups, suggesting that the administration of tyrosine-mutant AAV9 vectors was better tolerated. Tyrosine-mutant AAV9 vectors significantly improved transgene delivery to the lung (30%) compared with their wild-type counterparts, without eliciting an inflammatory response. Our results provide the impetus for further studies to exploit the use of AAV9 vectors as a tool for pulmonary gene therapy. © 2016 The Author(s) Published by S. Karger AG, Basel.

The effects of electromagnetic fields on the number of ovarian primordial follicles: An experimental study.

PubMed

Bakacak, Murat; Bostancı, Mehmet Sühha; Attar, Rukset; Yıldırım, Özge Kizilkale; Yıldırım, Gazi; Bakacak, Zeyneb; Sayar, Hamide; Han, Agahan

2015-06-01

The aim of this study was to evaluate the effect of an electromagnetic field (EMF), generated close to the ovaries, on primordial follicles. A total of 16 rats were used in this study. The study group consisted of rats exposed to an EMF in the abdominal region for 15 min/d for 15 days. Both the study and control group were composed of eight rats. After the treatment period of 15 days, the ovaries of the rats were extracted, and sections of ovarian tissue were taken for histological evaluation. The independent samples t test was used to compare the two groups. In the study group, the means of the right and left ovarian follicle numbers were 34.00 ± 10.20 and 36.00 ± 10.53, respectively. The average total ovarian follicle number was 70.00 ± 19.03. In the control group, the means of the right and left ovarian follicle numbers were 78.50 ± 25.98 and 71.75 ± 29.66, respectively, and the average total ovarian follicle number was 150.25 ± 49.53. The comparisons of the means of the right and left ovarian follicle numbers and the means of the total ovarian follicle numbers between the study and control groups indicated that the study group had significantly fewer follicles (p < 0.001, p = 0.011, and p = 0.002, respectively). This study found a significant decrease in the number of ovarian follicles in rats exposed to an EMF. Further clinical studies are needed to reveal the effects of EMFs on ovarian reserve and infertility. Copyright © 2015. Published by Elsevier Taiwan.

Intergenerational Relationships Between the Smoking Patterns of a Population-Representative Sample of US Mothers and the Smoking Trajectories of Their Children

PubMed Central

Miles, Jeremy N. V.

2012-01-01

Objectives. We assessed intergenerational transmission of smoking in mother-child dyads. Methods. We identified classes of youth smoking trajectories using mixture latent trajectory analyses with data from the Children and Young Adults of the National Longitudinal Survey of Youth (n = 6349). We regressed class membership on prenatal and postnatal exposure to maternal smoking, including social and behavioral variables, to control for selection. Results. Youth smoking trajectories entailed early-onset persistent smoking, early-onset experimental discontinued smoking, late-onset persistent smoking, and nonsmoking. The likelihood of early onset versus late onset and early onset versus nonsmoking were significantly higher among youths exposed prenatally and postnatally versus either postnatally alone or unexposed. Controlling for selection, the increased likelihood of early onset versus nonsmoking remained significant for each exposure group versus unexposed, as did early onset versus late onset and late onset versus nonsmoking for youths exposed prenatally and postnatally versus unexposed. Experimental smoking was notable among youths whose mothers smoked but quit before the child's birth. Conclusions. Both physiological and social role-modeling mechanisms of intergenerational transmission are evident. Prioritization of tobacco control for pregnant women, mothers, and youths remains a critical, interrelated objective. PMID:21852646

Effects of audiogenic hazard on fetal skeletal development in mice

NASA Astrophysics Data System (ADS)

Murata, M.; Kawade, F.; Kondo, M.; Takigawa, H.; Sakamoto, H.

1990-06-01

The effects of noise on fetal skeletal development in mice were examined. Pregnant ICR mice were exposed to a wide octave-band noise at 100 dB(C) for 6 hours a day in three ways: the first group was continuously exposed only on day 7 of pregnancy (group "N"); the second was exposed intermittently (15 min on/15 min off) only on day 7 of pregnancy (group "IN"); and the third was exposed to a continuous noise recurrently during days 7-12 of pregnancy (group "RN"). On day 18 of pregnancy, fetuses were removed and prepared as skeletons of cleared specimens stained with alizarin red S for examining skeletal development. Skeletal immaturity was observed in group "RN". The percentage of fetuses with skeletal malformations was significantly increased in group "N", as compared with the control. Significantly higher percentages of fetuses with variations in cervical vertebral arches were observed in groups "N" and "RN".

Genetic damage in human cells exposed to non-ionizing radiofrequency fields: a meta-analysis of the data from 88 publications (1990-2011).

PubMed

Vijayalaxmi; Prihoda, Thomas J

2012-12-12

Based on the 'limited' evidence suggesting an association between exposure to radiofrequency fields (RF) emitted from mobile phones and two types of brain cancer, glioma and acoustic neuroma, the International Agency for Research on Cancer has classified RF as 'possibly carcinogenic to humans' in group 2B. In view of this classification and the positive correlation between increased genetic damage and carcinogenesis, a meta-analysis was conducted to determine whether a significant increase in genetic damage in human cells exposed to RF provides a potential mechanism for its carcinogenic potential. The extent of genetic damage in human cells, assessed from various end-points, viz., single-/double-strand breaks in the DNA, incidence of chromosomal aberrations, micronuclei and sister chromatid exchanges, reported in a total of 88 peer-reviewed scientific publications during 1990-2011 was considered in the meta-analysis. Among the several variables in the experimental protocols used, the influence of five specific variables related to RF exposure characteristics was investigated: (i) frequency, (ii) specific absorption rate, (iii) exposure as continuous wave, pulsed wave and occupationally exposed/mobile phone users, (iv) duration of exposure, and (v) different cell types. The data indicated the following. (1) The magnitude of difference between RF-exposed and sham-/un-exposed controls was small with some exceptions. (2) In certain RF exposure conditions there was a statistically significant increase in genotoxicity assessed from some end-points: the effect was observed in studies with small sample size and was largely influenced by publication bias. Studies conducted within the generally recommended RF exposure guidelines showed a smaller effect. (3) The multiple regression analyses and heterogeneity goodness of fit data indicated that factors other than the above five variables as well as the quality of publications have contributed to the overall results. (4) More importantly, the mean indices for chromosomal aberrations, micronuclei and sister chromatid exchange end-points in RF-exposed and sham-/un-exposed controls were within the spontaneous levels reported in a large data-base. Thus, the classification of RF as possibly carcinogenic to humans in group 2B was not supported by genotoxicity-based mechanistic evidence. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparing Early Language Development in Monolingual- and Bilingual- Exposed Young Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Ohashi, J. Kaori; Mirenda, Pat; Marinova-Todd, Stefka; Hambly, Catherine; Fombonne, Eric; Szatmari, Peter; Bryson, Susan; Roberts, Wendy; Smith, Isabel; Vaillancourt, Tracy; Volden, Joanne; Waddell, Charlotte; Zwaigenbaum, Lonnie; Georgiades, Stelios; Duku, Eric; Thompson, Ann

2012-01-01

The purpose of this study was to compare a group of recently diagnosed bilingual-exposed children with autism (n = 20) aged 24-2 months with a matched group of monolingual-exposed children with autism (n = 40). The groups were matched with regard to chronological age at the time of language assessment and nonverbal IQ score, then compared with…

Low intensity microwave radiation induced oxidative stress, inflammatory response and DNA damage in rat brain.

PubMed

Megha, Kanu; Deshmukh, Pravin Suryakantrao; Banerjee, Basu Dev; Tripathi, Ashok Kumar; Ahmed, Rafat; Abegaonkar, Mahesh Pandurang

2015-12-01

Over the past decade people have been constantly exposed to microwave radiation mainly from wireless communication devices used in day to day life. Therefore, the concerns over potential adverse effects of microwave radiation on human health are increasing. Until now no study has been proposed to investigate the underlying causes of genotoxic effects induced by low intensity microwave exposure. Thus, the present study was undertaken to determine the influence of low intensity microwave radiation on oxidative stress, inflammatory response and DNA damage in rat brain. The study was carried out on 24 male Fischer 344 rats, randomly divided into four groups (n=6 in each group): group I consisted of sham exposed (control) rats, group II-IV consisted of rats exposed to microwave radiation at frequencies 900, 1800 and 2450 MHz, specific absorption rates (SARs) 0.59, 0.58 and 0.66 mW/kg, respectively in gigahertz transverse electromagnetic (GTEM) cell for 60 days (2h/day, 5 days/week). Rats were sacrificed and decapitated to isolate hippocampus at the end of the exposure duration. Low intensity microwave exposure resulted in a frequency dependent significant increase in oxidative stress markers viz. malondialdehyde (MDA), protein carbonyl (PCO) and catalase (CAT) in microwave exposed groups in comparison to sham exposed group (p<0.05). Whereas, levels of reduced glutathione (GSH) and superoxide dismutase (SOD) were found significantly decreased in microwave exposed groups (p<0.05). A significant increase in levels of pro-inflammatory cytokines (IL-2, IL-6, TNF-α, and IFN-γ) was observed in microwave exposed animal (p<0.05). Furthermore, significant DNA damage was also observed in microwave exposed groups as compared to their corresponding values in sham exposed group (p<0.05). In conclusion, the present study suggests that low intensity microwave radiation induces oxidative stress, inflammatory response and DNA damage in brain by exerting a frequency dependent effect. The study also indicates that increased oxidative stress and inflammatory response might be the factors involved in DNA damage following low intensity microwave exposure. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of Carnosine (Beta-Alanyl-L-Histidine) in an Experimental Rat Model of Acute Kidney Injury Due to Septic Shock

PubMed Central

Sahin, Sabiha; Donmez, Dilek Burukoglu

2018-01-01

Background Acute kidney injury (AKI) secondary to sepsis is a major cause of morbidity and mortality in the human intensive care unit (ICU). Kidney function and the histological findings of AKI were investigated in an experimental rat model with sepsis induced by cecal ligation and puncture (CLP) and compared with and without treatment with carnosine (beta-alanyl-L-histidine). Material/Methods Twenty-four Sprague-Dawley rats were randomly divided into three groups consisting eight rats in each: Group 1 – control; Group 2 – septic shock; and Group 3 – septic shock treated with carnosine. Femoral vein and artery catheterization were applied in all rats. Rats in Group 1 underwent laparotomy and catheterization. The other two groups with septic shock underwent laparotomy, CLP, catheterization, and bladder cannulation. Rats in Group 3 received an intraperitoneal (IP) injection of 250 mg/kg carnosine, 60 min following CLP. Rats were monitored for blood pressure, pulse rate, and body temperature to assess responses to postoperative sepsis, and 10 mL/kg saline replacement was administered. Twenty-four hours following CLP, rats were sacrificed, and blood and renal tissue samples were collected. Results Statistically significant improvements were observed in kidney function, tissue and serum malondialdehyde levels, routine blood values, biochemical indices, and in histopathological findings in rats in Group 3 who were treated with carnosine, compared with Group 2 exposed to septic shock without carnosine treatment. Conclusions Carnosine (beta-alanyl-L-histidine) has been shown to have beneficial effects in reducing AKI due to septic shock in a rat model of septicemia. PMID:29334583

Combined Impact of Gamma and Laser Radiation on Peripheral Blood of Rats in vivo

NASA Astrophysics Data System (ADS)

Zalesskaya, G. A.; Batay, L. E.; Koshlan, I. V.; Nasek, V. M.; Zilberman, R. D.; Milevich, T. I.; Govorun, R. D.; Koshlan, N. A.; Blaga, P.

2017-11-01

The impact of γ radiation of 137Cs (doses of 1 and 3 Gy), low-intensity laser radiation (λ = 670 nm, 5.3 or 10.6 J/cm2) as well as the influence of consecutive laser and γ radiation on peripheral blood and blood cells (erythrocytes, leukocytes, lymphocytes, granulocytes) were studied by analyzing the number of blood cells, blood absorption spectra, and activity of antioxidant defense enzymes. Two series of experiments were performed on four groups of rats. The rats of the control group (group 1) were not exposed to γ or laser radiation. In the experimental groups, single irradiation of the whole body of rats with γ radiation (group 2), three- or four-day over-vein irradiation of blood in the tail vein by low-intensity laser radiation (group 3), and successive three- or four-day irradiation of blood by laser and then a single irradiation of the whole body with γ radiation (group 4) were performed. It was shown that changes of the blood cell content in the experimental groups are accompanied by changes in the spectral characteristics of the blood and the activity of antioxidant defense enzymes. The radioprotective effect of low-intensity laser radiation is manifested as an increase in the average number of leukocytes and lymphocytes in the group as compared with the postradiation, as well as an increase in the activity of antioxidant protection enzymes. The possibility of using low-intensity optical radiation for correction of hematological disorders caused by ionizing radiation is discussed.

Dental health of young children prenatally exposed to buprenorphine. A concern of child neglect?

PubMed

Kivistö, K; Alapulli, H; Tupola, S; Alaluusua, S; Kivitie-Kallio, S

2014-06-01

To study the oral health and dental neglect of prenatally buprenorphine-exposed 3-year-old children. The study consisted of 51 children who as newborns tested positive for buprenorphine in a urine screen. The control group comprised 68 children previously unexposed to narcotics. The dentist examined the children and interviewed their guardians. Buprenorphine-exposed children exhibited significantly more early childhood caries than did the control group. Caries indices, the number of decayed, missing and filled teeth or tooth surfaces and decayed teeth were greater in the buprenorphine-exposed children than the control children (p = 0.004, p = 0.004, p = 0.001, respectively). In the buprenorphine group, more children showed visible plaque (p = 0.003) and fewer children were caries-free (p = 0.009) than in the control group. The control children's teeth were also brushed more often than the buprenorphine-exposed children's teeth (p = 0.001) and the parents were more involved in their children's tooth brushing than were those in the buprenorphine-exposed group (p = 0.035). More caries and dental neglect were found in buprenorphine-exposed children than in controls. These findings highlight the importance of routine dental appointments, caries screening and preventive care for children in substance-abusing families.

The protective effects of zinc in lead-induced testicular and epididymal toxicity in Wistar rats.

PubMed

Anjum, M Reshma; Madhu, P; Reddy, K Pratap; Reddy, P Sreenivasula

2017-03-01

The aim of this study was to investigate the beneficial effects of zinc (Zn) in preventing lead (Pb)-induced reproductive toxicity in Wistar rats. The rats were divided into four groups, namely, control group, Pb group, Zn group, and Pb + Zn group. Animals were exposed to Pb (819 mg of Pb/L) or Zn (71 mg of Zn/L) or both through drinking water for 65 days. Rats exposed to Pb showed decreased weights of testes and accessory sex organs. Significant decrease in the testicular daily sperm production, epididymal sperm count, motility, viability, and number of hypoosmotic tail coiled sperm was observed in Pb-exposed rats. Testicular 3β- and 17β-hydroxysteroid dehydrogenase activity levels and circulatory testosterone levels were also decreased significantly in Pb-exposed rats. A significant increase in the lipid peroxidation products with a significant decrease in the activities of catalase and superoxide dismutase were observed in the testes and epididymis of Pb-exposed rats. Moreover, the testicular architecture showed lumens devoid of sperm in Pb-exposed rats. Supplementation of Zn mitigated Pb-induced oxidative stress and restored the spermatogenesis and steroidogenesis in Pb-exposed rats. In conclusion, cotreatment of Zn is effective for recovering suppressed spermatogenesis, steroidogenesis, elevated oxidative status, and histological damage in the testis of rats treated with Pb.

Programming of the appetite-regulating neural network: a link between maternal overnutrition and the programming of obesity?

PubMed

Mühlhäusler, B S

2007-01-01

The concept of a functional foetal "appetite regulatory neural network" is a new and potentially critical one. There is a growing body of evidence showing that the nutritional environment to which the foetus is exposed during prenatal and perinatal development has long-term consequences for the function of the appetite-regulating neural network and therefore the way in which an individual regulates energy balance throughout later life. This is of particular importance in the context of evidence obtained from a wide range of epidemiological studies, which have shown that individuals exposed to an elevated nutrient supply before birth have an increased risk of becoming obese as children and adults. This review summarises the key pieces of experimental evidence, by our group and others, that have contributed to our current understanding of the programming of appetite, and highlights the important questions that are yet to be answered. It is clear that this area of research has the potential to generate, within the next few years, interventions that could begin to alleviate the adverse long-term consequences of being exposed to an elevated nutrient supply before birth.

Effects of in utero exposure to Tityus bahiensis scorpion venom in adult rats.

PubMed

Dorce, Ana Leticia Coronado; Dorce, Valquiria Abrão Coronado; Nencioni, Ana Leonor Abrahão

2010-01-01

The toxicity of Tityus bahiensis scorpion venom is well known, but there are little data about the damage in offspring of dams that were exposed to the venom during pregnancy. The objective of this work was to determine the toxic effects of venom in adult offspring of Wistar rats exposed to venom in utero. Dams were divided into a control group, subcutaneously injected with saline solution on the 10th (GD10) and 16th (GD16) days, and two experimental groups, subcutaneously injected with venom (2.5mg/kg) on GD10 or GD16, respectively. Adult offspring were evaluated according to behavioral development and neuronal integrity in the hippocampus. Tests performed in the activity box and in the enriched environment demonstrated that males from GD10 had motor decrease. Females from GD10 showed a depressive-like state and were more anxious, as demonstrated by the forced swimming test and social interaction. The plus-maze discriminative avoidance task demonstrated that GD16 males had lower levels of anxiety. The number of neuronal cells was decreased in CA1, CA3 and CA4 hippocampal areas of males and females from GD10 group and in CA1 of females and CA4 of males from GD16 group. Thus, we conclude that venom exposure in pregnant dams causes subtle alteration in the behavioral and neuronal development of offspring in adult life in a gender-dependent manner. Copyright (c) 2009 Elsevier Inc. All rights reserved.

Effect of unilateral extraction of molar teeth on suprahyoid muscles: macroscopic and ultrastructural aspects.

PubMed

Iyomasa, Mamie Mizusaki; Issa, João Paulo Mardegan; Siéssere, Selma; Regalo, Simone Cecílio Hallak; Watanabe, Ii-sei

2008-12-01

Anatomical and physiologic components are parts of the stomatognathic system and their interaction results in integrated functional activities. Important alterations in the masticatory system originated by dental loss affect the bone, oral mucosa and muscular function. Dental arch structures specifically designed to receive and expose teeth allow performance of their functions. But the distinction between bony and soft tissues is lost when teeth are removed since there is not a specific function to be completed. The aim of this study was to evaluate the macroscopic and ultrastructural effects of the unilateral extraction of molar teeth on the suprahyoid muscles function, using twenty young male gerbils (Meriones unguiculatus) as the experimental animal model. They were divided in experimental malocclusion (n=10) and control (n=10) groups. The experimental malocclusion group was submitted to exodontia of the left upper molars and the control group was not submitted to this procedure and served as sham-operated. For macroscopic analysis of the suprahyoid muscle, the skin was uplifted and the muscles dissected individually and removed for weight analysis according to Scherle method. The electron microscopy analysis was made in ultra thin sections of small suprahyoid muscle fragments from the experimental and control groups, examined in a Jeol 1010, 880 Kv transmission electron microscope. Several micrographs at magnifications of 3000x, 6000x, 30,000x were randomly selected for the qualitative analysis of the muscle fiber ultrastructures. Sixty days after the induced unilateral occlusal alteration no macroscopic morphologic changes was detected in the suprahyoid muscles and the muscle volume differences between the right and left sides and between groups were not significant. However, in the ultrastructural analysis suprahyoid muscles showed characteristics of specific adaptation to the unilateral occlusal alteration, by the reduced density of subsarcolemmal mitochondria and the shorter and less numerous ramifications in intermyofibrilar mitochondria localized between electronlucid myofibrils. It is concluded that unilateral exodontia of all the upper left molars affect the ultrastructural morphology of suprahyoid muscle fibers.

PHA-stimulated immune-responsiveness in mercury-dosed zebra finches does not match results from environmentally exposed songbirds.

PubMed

Caudill, Mitchell T; Spear, Eliza L; Varian-Ramos, Claire W; Cristol, Daniel A

2015-04-01

Dietary mercury exposure is associated with suppressed immune responsiveness in birds. This study examined the immune-responsiveness of domestic zebra finches (Taeniopygia guttata) experimentally exposed to mercury through their diet. We used the phytohemagglutinin (PHA) skin-swelling test to assay the effect of two modes of mercury exposure. Some finches received exposure to mercury only after reaching sexual maturity, while others were maintained on a mercury-dosed diet throughout life, including development. Each bird received one of five dietary concentrations of methylmercury cysteine (0.0, 0.3, 0.6, 1.2 or 2.4 ppm). In contrast to a study on wild songbirds at a mercury-contaminated site, we detected no relationship between mercury level and immunological response to PHA, regardless of mode of exposure. This result represents the first major difference found by our laboratory between wild birds exposed to environmental mercury and captive birds experimentally exposed to mercury.

Increased viability of odontoblast-like cells subjected to low-level laser irradiation

NASA Astrophysics Data System (ADS)

Oliveira, C. F.; Basso, F. G.; Lins, E. C.; Kurachi, C.; Hebling, J.; Bagnato, V. S.; de Souza Costa, C. A.

2010-07-01

Studies have shown that the increase of cell metabolism depends on the low level laser therapy (LLLT) parameters used to irradiate the cells. However, the optimal laser dose to up-regulate pulp cell activity remains unknown. Consequently, the aim of this study was to evaluate the metabolic response of odontoblast-like cells (MDPC-23) exposed to different LLLT doses. Cells at 20000 cells/cm2 were seeded in 24-well plates using plain culture medium (DMEM) and were incubated in a humidified incubator with 5% CO2 at 37°C. After 24 h, the culture medium was replaced by fresh DMEM supplemented with 5% (stress by nutritional deficit) or 10% fetal bovine serum (FBS). The cells were exposed to different laser doses from a near infrared diode laser prototype designed to provide a uniform irradiation of the wells. The experimental groups were: G1: 1.5 J/cm2 + 5% FBS; G2: 1.5 J/cm2 + 10% FBS; G3: 5 J/cm2 + 5% FBS; G4: 5 J/cm2 + 10% FBS; G5: 19 J/cm2 + 5% FBS; G6: 19 J/cm2 + 10% FBS. LLLT was performed in 3 consecutive irradiation cycles with a 24-hour interval. Non-irradiated cells cultured in DMEM supplemented with either 5 or 10% FBS served as control groups. The analysis of the metabolic response was performed by the MTT assay 3 h after the last irradiation. G1 presented an increase in SDH enzyme activity and differed significantly (Mann-Whitney test, p < 0.05) from the other groups. Analysis by scanning electron microscopy showed normal cell morphology in all groups. Under the tested conditions, LLLT stimulated the metabolic activity of MDPC-23 cultured in DMEM supplemented with 5% FBS and exposed to a laser dose of 1.5 J/cm2. These findings are relevant for further studies on the action of near infrared lasers on cells with odontoblast phenotype.

In vivo evaluation of the potential neurotoxicity of aerosols released from mechanical stress of nano-TiO2 additived paints in mice chronically exposed by inhalation

NASA Astrophysics Data System (ADS)

Manixay, S.; Delaby, S.; Gaie-Levrel, F.; Wiart, M.; Motzkus, C.; Bencsik, A.

2017-06-01

Engineered Nanomaterials (ENM) provide technical and specific benefits due to their physical-chemical properties at the nanometer scale. For instance, many ENM are used to improve products in the building industry. Nanoscaled titanium dioxide (TiO2) is one of the most used ENM in this industry. Incorporated in different matrix, cement, glass, paints… TiO2 nanoparticles (NPs) provide the final product with anti-UV, air purification and self-cleaning properties, thanks to their photocatalytic activity. However, ageing processes of such products, as photocatalytic paints, during a mechanical stress have been shown to release TiO2 NPs from this matrix associated with sanding dust. Thus, workers who sand painted walls could be exposed to TiO2 NPs through inhalation. As inhalation may lead to a translocation of particulate matter to the brain via olfactory or trigeminal nerves, there is an urgent need for evaluating a potential neurotoxicity. In order to provide new knowledge on this topic, we developed a dedicated experimental set-up using a rodent model exposed via inhalation. The aerosol released from a mechanical stress of photocatalytic paints containing TiO2 NPs was characterized and coupled to an exposition chamber containing group of mice free to move and chronically exposed (2 hours per day for 5 days a week during 8 weeks).

Effects of emissions from sugar cane burning on the trachea and lungs of Wistar rats

PubMed Central

Matos, Verena Sampaio Barbosa; Gomes, Felipe da Silva; Oliveira, Tarcio Macena; Schulz, Renata da Silva; Ribeiro, Lídia Cristina Villela; Gonzales, Astria Dias Ferrão; Lima, Januário Mourão; Guerreiro, Marcos Lázaro da Silva

2017-01-01

ABSTRACT Objective: To evaluate the effects of exposure to emissions from sugar cane burning on inflammatory mechanisms in tissues of the trachea and lung parenchyma in Wistar rats after different periods of exposure. Methods: This was an experimental open randomized study. The animals were divided into four groups: a control group (CG) underwent standard laboratory conditions, and three experimental groups were exposed to emissions from sugar cane burning over different periods of time, in days-1 (EG1), 7 (EG7), and 21 (EG21). After euthanasia with 200 mg/kg of ketamine/xylazine, fragments of trachea and lung were collected and fixed in 10% formalin. Histological analyses were performed with H&E and picrosirius red staining. Results: No inflammatory infiltrates were found in the tissues of CG rats. The histological examination of tissues of the trachea and lung parenchyma revealed that the inflammatory process was significantly more intense in EG7 than in the CG (p < 0.05 and p < 0.01, respectively). In comparison with the CG and EG1, angiogenesis in the lung parenchyma and collagen deposition in tracheal tissues were significantly greater only in EG21 (p < 0.001 and p < 0.01, respectively). Conclusions: In this sample, emissions from sugar cane burning induced acute focal and diffuse inflammation in the lamina propria of tracheal tissues, with no loss of ciliated epithelial tissue. In the lung parenchyma of the animals in the experimental groups, there was interstitial and alveolar edema, together with polymorphonuclear cell infiltrates. PMID:28746532

A tailored multicomponent program to reduce discomfort in critically ill patients: a cluster-randomized controlled trial.

PubMed

Kalfon, Pierre; Baumstarck, Karine; Estagnasie, Philippe; Geantot, Marie-Agnès; Berric, Audrey; Simon, Georges; Floccard, Bernard; Signouret, Thomas; Boucekine, Mohamed; Fromentin, Mélanie; Nyunga, Martine; Sossou, Achille; Venot, Marion; Robert, René; Follin, Arnaud; Audibert, Juliette; Renault, Anne; Garrouste-Orgeas, Maïté; Collange, Olivier; Levrat, Quentin; Villard, Isabelle; Thevenin, Didier; Pottecher, Julien; Patrigeon, René-Gilles; Revel, Nathalie; Vigne, Coralie; Azoulay, Elie; Mimoz, Olivier; Auquier, Pascal

2017-12-01

Critically ill patients are exposed to stressful conditions and experience several discomforts. The primary objective was to assess whether a tailored multicomponent program is effective for reducing self-perceived discomfort. In a cluster-randomized two-arm parallel trial, 34 French adult intensive care units (ICUs) without planned interventions to reduce discomfort were randomized, 17 to the arm including a 6-month period of program implementation followed by a 6-month period without the program (experimental group), and 17 to the arm with an inversed sequence (control group). The tailored multicomponent program consisted of assessment of ICU-related self-perceived discomforts, immediate and monthly feedback to healthcare teams, and site-specific tailored interventions. The primary outcome was the overall discomfort score derived from the 16-item IPREA questionnaire (0, minimal, 100, maximal overall discomfort) and the secondary outcomes were the discomfort scores of each IPREA item. IPREA was administered on the day of ICU discharge with a considered timeframe from the ICU admission until ICU discharge. During a 1-month assessment period, 398 and 360 patients were included in the experimental group and the control group, respectively. The difference (experimental minus control) of the overall discomfort score between groups was - 7.00 (95% CI - 9.89 to - 4.11, p < 0.001). After adjustment (age, gender, ICU duration, mechanical ventilation duration, and type of admission), the program effect was still positive for the overall discomfort score (difference - 6.35, SE 1.23, p < 0.001) and for 12 out of 16 items. This tailored multicomponent program decreased self-perceived discomfort in adult critically ill patients. Clinicaltrials.gov Identifier NCT02442934.

Effect of administration of vitamins C and E on fertilization capacity of rats exposed to noise stress.

PubMed

Saki, Ghasem; Jasemi, Majid; Sarkaki, Ali Reza; Fathollahi, Ali

2013-01-01

The aims of this study were to evaluate the effects of administration of Vitamins C and E on fertilization capacity in rats exposed to noise stress. 40 adult male rats were randomly divided into 5 equal groups. Group 1 as controls who were not exposed to noise and groups 2-5 exposed to noise with 90-120 dB intensity and 300-350 Hz frequency from 7 pm to 7 am everyday for 50 days. Group 2 exposed to noise and did not receive Vitamins. Group 3 received vitamin C, Group 4 received Vitamin E. Group 5 received Vitamins C and E concomitantly. After 50 days, serum Follicle-stimulating hormone (FSH), Luteinizing hormone (LH) and testosterone were calculated. Then each rat was left with three female rats for mating. Pregnant females were sacrificed on the 19 th day of pregnancy and evaluated for the presence and number of viable, dead and absorbed fetuses. The level of FSH, LH and testosterone significantly decreased in rats exposed to noise (P < 0.05). By administration of Vitamins in groups 3-5 we observed that the level of hormones significantly increased in compared to group 2 (P < 0.05). The fertilization capacity of male rats in groups 3-5 significantly increased in compared to group 2 (P < 0.05). There was significant difference between groups 1 and 2 in case of fertilization capacity (P = 0.001). The data in this study strongly suggests a negative role for noise stress on level of FSH, LH and testosterone level and also fertilization capacity of male rats. To complement the information it is suggested that this research be done on human samples.

Evidence from catch-up growth and hoarding behavior of rats that exposure to hypobaric air lowers the body-mass set point.

PubMed

Bozzini, Carlos E; Lezón, Christian E; Norese, María F; Conti, María I; Martínez, María P; Olivera, María I; Alippi, Rosa M

2005-01-01

The depression of body growth rate and the reduction of body mass for chronological age and gender in growing experimental animals exposed to hypobaric air (simulated high altitude = SHA) have been associated with hypophagia because of reduced appetite. Catch-up growth during protein recovery after a short period of protein restriction only occurs if food intake becomes super-normal, which should not be possible under hypoxic conditions if the set-point for appetite is adjusted by the level of SHA. The present investigation was designed to test the hypothesis that growth retardation during exposure to SHA is due to an alteration of the neural mechanism for setting body mass size rather than a primary alteration of the central set-point for appetite. One group of female rats aged 35 d were exposed to SHA (5460m) in a SHA chamber for 27 d (HX rats). Other group was maintained under local barometric pressure conditions (NX rats). One half of both NX and HX rats were fed a protein-free diet for the initial 9 d of the experimental period. From this time on, they were fed a diet containing 20% protein, as were the remaining rats of both groups during the entire experimental period. The growth rates of both mass and length of the body were significantly depressed in well-nourished rats exposed to SHA during the entire observation period when compared to normoxic ones. At its end, body mass and body length were 24% and 21% less in HX than in NX rats. Growth rates were negatively affected by protein restriction in both NX and HX rats. During protein recovery, they reached supernormal values in response to supernormal levels of energy intake that allowed a complete catch-up of both body mass and length. The finding that energy intake during the period of protein rehabilitation in HX rats previously stunted by protein restriction was markedly higher than in HX control ones at equal levels of hypoxia demonstrates that the degree of hypoxia does not determine directly the degree of appetite and energy intake. Furthermore, the finding that catch-up growth in the stunted HX rats returns the animal only to the stunted size appropriate for the hypoxic animal supports the hypothesis that hypoxia lowers the set-point for body mass size, which is reached by inhibition of appetite. Confirmation of the hypothesis was done by assessment of the set-point of body mass by the behavioral method of the weight threshold to hoard food. It was lowered by 17.0% in HX rats.

Cancer mortality among atomic bomb survivors exposed as children.

PubMed

Goto, Hitomi; Watanabe, Tomoyuki; Miyao, Masaru; Fukuda, Hiromi; Sato, Yuzo; Oshida, Yoshiharu

2012-05-01

To compare cancer mortality among A-bomb survivors exposed as children with cancer mortality among an unexposed control group (the entire population of Japan, JPCG). The subjects were the Hiroshima and Nagasaki A-bomb survivor groups (0-14 years of age in 1945) reported in life span study report 12 (follow-up years were from 1950 to 1990), and a control group consisting of the JPCG. We estimated the expected number of deaths due to all causes and cancers of various causes among the exposed survivors who died in the follow-up interval, if they had died with the same mortality as the JPCG (0-14 years of age in 1945). We calculated the standardized mortality ratio (SMR) of A-bomb survivors in comparison with the JPCG. SMRs were significantly higher in exposed boys overall for all deaths, all cancers, leukemia, and liver cancer, and for exposed girls overall for all cancers, solid cancers, liver cancer, and breast cancer. In boys, SMRs were significantly higher for all deaths and liver cancer even in those exposed to very low doses, and for all cancers, solid cancers, and liver cancer in those exposed to low doses. In girls, SMRs were significantly higher for liver cancer and uterine cancer in those exposed to low doses, and for leukemia, solid cancers, stomach cancer, and breast cancer in those exposed to high doses. We calculated the SMRs for the A-bomb survivors versus JPCG in childhood and compared them with a true non-exposed group. A notable result was that SMRs in boys exposed to low doses were significantly higher for solid cancer.

Neurotoxicity of low bisphenol A (BPA) exposure for young male mice: Implications for children exposed to environmental levels of BPA.

PubMed

Zhou, Yuanxiu; Wang, Zhouyu; Xia, Minghan; Zhuang, Siyi; Gong, Xiaobing; Pan, Jianwen; Li, Chuhua; Fan, Ruifang; Pang, Qihua; Lu, Shaoyou

2017-10-01

To investigate the neuron toxicities of low-dose exposure to bisphenol A (BPA) in children, mice were used as an animal model. We examined brain cell damage and the effects of learning and memory ability after BPA exposure in male mice (4 weeks of age) that were divided into four groups and chronically received different BPA treatments for 8 weeks. The comet assay and hippocampal neuron counting were used to detect the brain cell damage. The Y-maze test was applied to test alterations in learning and memory ability. Long term potentiation induction by BPA exposure was performed to study the potential mechanism of performance. The percentages of tail DNA, tail length and tail moment in brain cells increased with increasing BPA exposure concentrations. Significant differences in DNA damage were observed among the groups, including between the low-dose and control groups. In the Y-maze test, the other three groups qualified for the learned standard one day earlier than the high-exposed group. Furthermore, the ratio of qualified mice in the high-exposed group was always the lowest among the groups, indicating that high BPA treatment significantly altered the spatial memory performance of mice. Different BPA treatments exerted different effects on the neuron numbers of different regions in the hippocampus. In the CA1 region, the high-exposed group had a significant decrease in neuron numbers. A non-monotonic relationship was observed between the exposure concentrations and neuron quantity in the CA3 region. The hippocampal slices in the control and medium-exposed groups generated long-term potentiation after induction by theta burst stimulation, but the low-exposed group did not. A significant difference was observed between the control and low-exposed groups. In conclusion, chronic exposure to a low level of BPA had adverse effects on brain cells and altered the learning and memory ability of adolescent mice. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chronic diseases and mortality among immigrants to Israel from areas contaminated by the Chernobyl disaster: a follow-up study.

PubMed

Slusky, Danna A; Cwikel, Julie; Quastel, Michael R

2017-05-01

To examine six chronic diseases and all-cause mortality among immigrants to Israel from areas contaminated by the Chernobyl accident. The medical data were obtained from the two largest HMOs in Israel. In the assessment of chronic diseases, individuals were divided into three groups: less exposed (n = 480), more exposed (n = 359), and liquidators (n = 45) and in the mortality analysis, into two groups: less exposed (n = 792) and more exposed (n = 590). Compared to the less exposed, adults from the more exposed group had increased odds of respiratory disorders (OR = 2.34, 95% CI 1.21, 4.54) and elevated odds, with borderline significance, of ischemic heart disease (OR = 2.01, 95% CI 0.97, 4.20). In addition, the liquidators had increased odds of hypertension compared to the less exposed (OR = 2.64, 95% CI 1.24, 5.64). The Cox proportional-hazards model indicated no difference in the ratio of all-cause mortality between the exposed groups during the follow up period. Our study, conducted approximately two decades after the accident, suggests that exposure to radionuclides may be associated with increased odds of respiratory disorders and hypertension.

Histological assessments on the abnormalities of mouse epiphyseal chondrocytes with short term centrifugal loading.

PubMed

de Freitas, Paulo Henrique Luiz; Kojima, Taku; Ubaidus, Sobhan; Li, Minqi; Shang, Guangwei; Takagi, Ritsuo; Maeda, Takeyasu; Oda, Kimimitsu; Ozawa, Hidehiro; Amizuka, Norio

2007-08-01

We have examined the morphological changes in chondrocytes after exposure to experimental hypergravity. Tibial epiphyseal cartilages of 17-days-old mouse fetuses were exposed to centrifugation at 3G for 16 h mimicking hypergravitational environment (experimental group), or subjected to stationary cultures (control group). Centrifugation did not affect the sizes of epiphyseal cartilage, chondrocyte proliferation, type X collagen-positive hypertrophic zone, and the mRNA expressions of parathyroid hormone-related peptide and fibroblast growth factor receptor III. However, centrifuged chondrocytes showed abnormal morphology and aberrant spatial arrangements, resulting in disrupted chondrocytic columns. Through histochemical assessments, actin filaments were shown to distribute evenly along cell membranes of control proliferative chondrocytes, while chondrocytes subjected to centrifugal force developed a thicker layer of actin filaments. Transmission electron microscopic observations revealed spotty electron-dense materials underlying control chondrocytes' cell membranes, while experimental chondrocytes showed their thick layer. In the intracolumnar regions of the control cartilage, longitudinal electron-dense fibrils were associated with short cytoplasmic processes of normal chondrocytes, indicating assumed cell-tomatrix interactions. These extracellular fibrils were disrupted in the centrifuged samples. Summarizing, altered actin filaments associated with cell membranes, irregular cell shape and disappearance of intracolumnar extracellular fibrils suggest that hypergravity disturbs cell-to-matrix interactions in our cartilage model.

An experimental study of the combined effects of n-hexane and methyl ethyl ketone.

PubMed Central

Takeuchi, Y; Ono, Y; Hisanaga, N; Iwata, M; Aoyama, M; Kitoh, J; Sugiura, Y

1983-01-01

This study was intended to determine whether or not methyl ethyl ketone (MEK) enhances the neurotoxicity of n-hexane at low concentration and after long term exposure. Separate groups of eight rats were exposed to 100 ppm n-hexane, 200 ppm MEK, 100 ppm n-hexane plus 200 ppm MEK, or fresh air in an exposure chamber for 12 hours a day for 24 weeks. The body weight, motor nerve conduction velocity (MCV), distal motor latency (DL), and mixed nerve conduction velocities (MNCVs) were measured before exposure and after four, eight, 12, 16, 20, and 24 weeks' exposure. One rat of each group was histopathologically examined after 24 weeks' exposure. Exposure of 100 ppm n-hexane did not significantly decrease the functions of the peripheral nerve throughout the experiment. Exposure to 200 ppm MEK significantly increased MCV and MNCVs and decreased DL after four weeks' exposure, but at this later stage no significant changes were found throughout the experiment by comparison with the controls. Mixed exposure to 100 ppm n-hexane plus 200 ppm MEK significantly decreased by comparison with the controls. On histopathological examination of the tail nerve, however, no changes were found in any of the exposed groups or the controls. These results suggest that MEK might enhance the neurotoxicity of n-hexane at a low concentration, and mixed exposures to n-hexane and MEK should be avoided. PMID:6830718

Influence of 340 mT static magnetic field on germination potential and mid-infrared spectrum of wheat.

PubMed

Ćirković, Saša; Bačić, Jasmina; Paunović, Novica; Popović, Tamara B; Trbovich, Alexander M; Romčević, Nebojša; Ristić-Djurović, Jasna L

2017-10-01

In a number of studies, a static magnetic field was observed to positively influence the growing process of various plants; however, the effect has not yet been related to possible structural changes. We investigate if the static magnetic field that improves germination of wheat also alters wheat's near-infrared spectrum. Two groups of seeds were exposed to 340 mT for 16 h cumulatively. The first group was exposed 8 days for 2 h per day, while the second group was exposed 4 h per day for 4 consecutive days. One half of each of the exposed seed groups as well as of the unexposed control groups was sown, and the other half was used for mid-infrared spectra measurements. The sown seeds were monitored for 3 weeks after sowing. Germination of the groups exposed to the magnetic field was faster compared to corresponding non-exposed groups that were grown under the same conditions. The magnetic field exposure caused the enhancement of one OH peak at 3,369 cm -1 and two CO peaks at 1,662 cm -1 and 1,740 cm -1 in the mid-infrared spectrum. The effect was more pronounced for the 4 day, 4 h/day exposure. Bioelectromagnetics. 38:533-540, 2017.© 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Effects of subchronic extremely low-frequency electromagnetic field exposure on biochemical parameters in rats.

PubMed

Luo, Xue; Ma, Lingjuan; Gao, Peng; Zhang, Yanwen

2017-04-01

The objective of the present study was to systematically determine the effects of 50 Hertz (Hz) magnetic fields (MFs) on biochemical parameters in rats. Sixty-four adult (5 weeks old, 140-165 g) male Sprague-Dawley rats were randomly divided into four groups: sham, 20 µTesla (µT), 100 µT, and 500 µT 50 Hz MF ( n = 16 in each group). The rats in the MF groups were exposed for 2 h daily for up to 4 weeks. Under these experimental conditions, body weight, organ coefficients, biochemical parameters (blood lipids, myocardial enzymes, liver function, and renal function) were measured. We found that 50 Hz MFs had no significant effects on growth or on the majority of blood biochemical parameters, with the exception of creatinine and cholesterol. However, the changes in creatinine and cholesterol were relatively small and unlikely to be clinically relevant.

[Lack of protection against gentamicin ototoxicity by auditory conditioning with noise].

PubMed

Strose, Alex; Hyppolito, Miguel Ângelo; Colombari, Gleice Cristina; Rossato, Maria; Oliveira, Jose Antônio Aparecido de

2014-01-01

Auditory conditioning consists of the pre-exposure to low levels of a potential harmful agent to protect against a subsequent harmful exposure. To confirm if conditioning with an agent different from that used to cause the trauma can also be effective. This was an experimental study with 17 guinea pigs, divided into three groups: an ototoxic control group (Cont) that received intramuscular administration of gentamicin 160 mg/kg/day for ten consecutive days, but no sound exposure; a sound control group (Sound) that was exposed to 85 dB broadband noise centered at 4 kHz, 30 min each day for ten consecutive days, but received no ototoxic medications; and an experimental group (Expt) that received sound exposure identical to the Sound group and after each noise presentation, received gentamicin similarly to Cont group. The animals were evaluated by distortion product otoacoustic emissions (DPOAEs), brainstem auditory evoked potentials (BAEPs), and scanning electron microscopy. The animals that were conditioned with noise did not show any protective effect compared with the ones that received only the ototoxic gentamicin administration. This lack of protection was observed functionally and morphologically. Conditioning with 85 dB broadband noises, 30 min a day for ten consecutive days does not protect against an ototoxic gentamicin administration of 160 mg/kg/day for ten consecutive days in the guinea pig. Copyright © 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Effects of electromagnetic pulse on polydactyly of mouse fetuses.

PubMed

Yang, Ming-Juan; Liu, Jun-Ye; Wang, Ya-Feng; Lang, Hai-Yang; Miao, Xia; Zhang, Li-Yan; Zeng, Li-Hua; Guo, Guo-Zhen

2013-07-01

There is an increasing public concern regarding potential health impacts from electromagnetic radiation exposure. Embryonic development is sensitive to the external environment, and limb development is vital for life quality. To determine the effects of electromagnetic pulse (EMP) on polydactyly of mouse fetuses, pregnant mice were sham-exposed or exposed to EMP (400 kV/m with 400 pulses) from Days 7 to 10 of pregnancy (Day 0 = day of detection of vaginal plug). As a positive control, mice were treated with 5-bromodeoxyuridine on Days 9 and 10. On Days 11 or 18, the fetuses were isolated. Compared with the sham-exposed group, the group exposed to EMP had increased rates of polydactyly fetuses (5.1% vs. 0.6%, P < 0.05) and abnormal gene expression (22.2% vs. 2.8%, P < 0.05). Ectopic expression of Fgf4 was detected in the apical ectodermal ridge, whereas overexpression and ectopic expression of Shh were detected in the zone of polarizing activity of limbs in the EMP-exposed group and in the positive control group. However, expression of Gli3 decreased in mesenchyme cells in those two groups. The percentages of programmed cell death of limbs in EMP-exposed and positive control group were decreased (3.57% and 2.94%, respectively, P < 0.05, compared with 7.76% in sham-exposed group). In conclusion, polydactyly induced by EMP was accompanied by abnormal expression of the above-mentioned genes and decreased percentage of programmed cell death during limb development. Copyright © 2013 Elsevier Inc. All rights reserved.

Cognition Enhancing Activity of Sulforaphane Against Scopolamine Induced Cognitive Impairment in Zebra Fish (Danio rerio).

PubMed

Rajesh, Venugopalan; Ilanthalir, Sakthivel

2016-10-01

Several epidemiological studies have shown that consumption of large quantities of vegetables especially cruciferous vegetables (Broccoli and Brussels sprouts) can protect against chronic diseases. Sulforaphane, an isothiocynate found in cruciferous vegetables has been demonstrated to have neuroprotective effects in several experimental paradigms. This study was undertaken to examine the effect of sulforaphane on cognitive impairment in zebra fish model using a novel method of fear conditioning. Initially, the normal behaviour of zebra fishes was studied in light-dark tank for 10 min daily for 10 days. Fishes were then divided into seven groups of twelve in each. Group I served as normal, group II served as fear conditioned control, group III and group IV were sulforaphane (25 µM/L) and piracetam (200 mg/L) treated respectively. Group V served as scopolamine (400 µM/L) induced memory impairment fishes. Group VI and VII were sulforaphane (25 µM/L) and piracetam (200 mg/L) treated scopolamine induced memory impairment groups respectively. In normal behavioural analysis, fishes preferred to stay in dark compartment. The average number of entries into the dark and time spent in dark were significantly more. Fishes in group II to VII were individually subjected to fear conditioning passive avoidance task and evaluated for learned task memory. It was observed that the average number of entries into dark and time spent in dark were significantly decreased. After exposure to respective treatment fishes in group III to VII were subjected to cognitive evaluation. There was no significant difference in cognition of group III and IV fishes exposed to sulforaphane and piracetam alone respectively. Fishes exposed to scopolamine showed a significant cognitive impairment. Sulforaphane exposure prior to scopolamine significantly retained the memory of learned task. These findings suggest that sulforaphane might be a promising therapeutic agent for cognitive enhancement in Alzheimer's disease.

The relationship between blood lead levels and occupational exposure in a pregnant population.

PubMed

La-Llave-León, Osmel; Salas Pacheco, José Manuel; Estrada Martínez, Sergio; Esquivel Rodríguez, Eloísa; Castellanos Juárez, Francisco X; Sandoval Carrillo, Ada; Lechuga Quiñones, Angélica María; Vázquez Alanís, Fernando; García Vargas, Gonzalo; Méndez Hernández, Edna Madai; Duarte Sustaita, Jaime

2016-12-07

Pregnant women exposed to lead are at risk of suffering reproductive damages, such as miscarriage, preeclampsia, premature delivery and low birth weight. Despite that the workplace offers the greatest potential for lead exposure, there is relatively little information about occupational exposure to lead during pregnancy. This study aims to assess the association between blood lead levels and occupational exposure in pregnant women from Durango, Mexico. A cross-sectional study was carried out in a population of 299 pregnant women. Blood lead was measured in 31 women who worked in jobs where lead is used (exposed group) and 268 who did not work in those places (control group). Chi-square test was applied to compare exposed and control groups with regard to blood lead levels. Odds ratio (OR) and 95% confidence intervals (CI) were calculated. Multivariable regression analysis was applied to determine significant predictors of blood lead concentrations in the exposed group. Exposed women had higher blood lead levels than those in the control group (4.00 ± 4.08 μg/dL vs 2.65 ± 1.75 μg/dL, p = 0.002). Furthermore, women in the exposed group had 3.82 times higher probability of having blood lead levels ≥ 5 μg/dL than those in the control group. Wearing of special workwear, changing clothes after work, living near a painting store, printing office, junkyard or rubbish dump, and washing the workwear together with other clothes resulted as significant predictors of elevated blood lead levels in the exposed group. Pregnant working women may be at risk of lead poisoning because of occupational and environmental exposure. The risk increases if they do not improve the use of protective equipment and their personal hygiene.

[Interpretation of the values of urinary cotinine in smokers and non-smokers].

PubMed

Roussel, G; Le Quang, N T; Miguères, M L; Roche, D; Mongin-Charpin, D; Chrétien, J; Ekindjian, O G

1991-01-01

The values of urinary cotinine measured using high performance liquid chromatography in 125 adults (44 men and 81 women) were compared with the degree of intoxication and/or exposure to tobacco experienced over six consecutive days by auto-questionnaire. The subjects were classified in 6 groups: non exposed non smokers and non smokers exposed for less than one hour (1, n = 16); non smokers exposed for between 1 and 10 hours (2, n = 26); non smokers exposed for more than 10 hours and less than 30 hours (3, n = 33); non smokers exposed for more than 30 hours (4, n = 13); smokers smoking less than 20 cigarettes per day (5, n = 16); smokers smoking 20 cigarettes or more per day (6, n = 21). The measurements were made on urine specimens from the first morning (fraction F1), from the day and night (F2) and those of the second morning (F3). The results were expressed in micrograms/fraction and were as follows: Group 1: 37.3 (F1); 149.5 (F2); 26.8 (F3)--Group 2: 81.2; 234.1; 75.4--Group 3: 121.1; 383.1; 80.7--Group 4: 98.8; 253.7; 117.2--Group 5: 206.9; 773.8; 188--Group 6: 483.1; 1908.2; 431.3. Cotinine was found in all individuals whether they declared that they were exposed or non exposed (with the exception of a single person amongs the latter). In spite of a certain amount of overlapping between the results of the individuals in groups 4 and 5, the values obtained enabled a differentiation between the degrees of tobacco absorption.(ABSTRACT TRUNCATED AT 250 WORDS)

The primary case is not enough: Variation among individuals, groups and social networks modify bacterial transmission dynamics.

PubMed

Keiser, Carl N; Pinter-Wollman, Noa; Ziemba, Michael J; Kothamasu, Krishna S; Pruitt, Jonathan N

2018-03-01

The traits of the primary case of an infectious disease outbreak, and the circumstances for their aetiology, potentially influence the trajectory of transmission dynamics. However, these dynamics likely also depend on the traits of the individuals with whom the primary case interacts. We used the social spider Stegodyphus dumicola to test how the traits of the primary case, group phenotypic composition and group size interact to facilitate the transmission of a GFP-labelled cuticular bacterium. We also compared bacterial transmission across experimentally generated "daisy-chain" vs. "star" networks of social interactions. Finally, we compared social network structure across groups of different sizes. Groups of 10 spiders experienced more bacterial transmission events compared to groups of 30 spiders, regardless of groups' behavioural composition. Groups containing only one bold spider experienced the lowest levels of bacterial transmission regardless of group size. We found no evidence for the traits of the primary case influencing any transmission dynamics. In a second experiment, bacteria were transmitted to more individuals in experimentally induced star networks than in daisy-chains, on which transmission never exceeded three steps. In both experimental network types, transmission success depended jointly on the behavioural traits of the interacting individuals; however, the behavioural traits of the primary case were only important for transmission on star networks. Larger social groups exhibited lower interaction density (i.e. had a low ratio of observed to possible connections) and were more modular, i.e. they had more connections between nodes within a subgroup and fewer connections across subgroups. Thus, larger groups may restrict transmission by forming fewer interactions and by isolating subgroups that interacted with the primary case. These findings suggest that accounting for the traits of single exposed hosts has less power in predicting transmission dynamics compared to the larger scale factors of the social groups in which they reside. Factors like group size and phenotypic composition appear to alter social interaction patterns, which leads to differential transmission of microbes. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

Experimental COPD induced by solid combustible burn smoke in rats: a study of the emphysematous changes of the pulmonary parenchyma.

PubMed

Murărescu, Elena Doina; Eloae-Zugun, Fl; Mihailovici, Maria Sultana

2008-01-01

According to the GOLD 2006 definition, COPD is a preventable and treatable pathological situation characterized by the partially reversible airflow limitation determined by a variable proportion mixture of small airways disease (obliterative bronchiolitis) and parenchyma destruction (emphysema). A major impediment in the study of the COPD is represented by the fact the fundamental morphological changes that determine the major pulmonary dysfunction take place in the small, peripheral, airways, at the bronchiolo-alveolar attachments. That is why the experimental model of COPD developed progressively to the transgenic mouse. There are many experimental studies on the animal models that have obtained emphysema rapidly through intratraheal instillation of elastasis or bronchitis/bronchiolitis through intratraheal instillation of particles. It is accepted that the unnatural character of aggression, that does not permit the natural evolution of the inflammatory phenomenon, limits these models and tissue remodeling that take place in COPD patients. It is well known that cigarette smoking is a major cause of COPD. There have been reported some cases of COPD in never smoking patients exposed to air pollutants. We aimed to create an experimental model of COPD in rat through exposure to smoke resulted from solid combustibles burn for the same period and in the same conditions of cigarette smoke exposure and to compare the pulmonary morphological changes. Thirty Wistar rats were divided into three groups (n = 10): (1) the control group (C), (2) the cigarette smoke group (CS), and (3) the solid combustible smoke group (SCS). Apart from the control group, these were treated with solid combustibles smoke (SCS group) or cigarette smoke (CS group) for six months. Morphological and morphometry studies have been assessed. We have established a rat COPD model based on natural cigarette smoke exposure versus solid combustible burn resulted smoke, usable for a further approach in human non-smoker COPD investigation. Out procedures resulted in clear pulmonary morphological lesions that are characteristic for COPD. The achieved data support the idea that solid combustible burn resulted smoke determines emphysematous parenchyma lesions that are similar, but with an attenuated morphological appearance when comparing to the cigarette smoke exposure.

Effects of ozone therapy on facial nerve regeneration.

PubMed

Ozbay, Isa; Ital, Ilker; Kucur, Cuneyt; Akcılar, Raziye; Deger, Aysenur; Aktas, Savas; Oghan, Fatih

Ozone may promote moderate oxidative stress, which increases antioxidant endogenous systems. There are a number of antioxidants that have been investigated therapeutically for improving peripheral nerve regeneration. However, no previous studies have reported the effect of ozone therapy on facial nerve regeneration. We aimed to evaluate the effect of ozone therapy on facial nerve regeneration. Fourteen Wistar albino rats were randomly divided into two groups with experimental nerve crush injuries: a control group, which received saline treatment post-crush, and an experimental group, which received ozone treatment. All animals underwent surgery in which the left facial nerve was exposed and crushed. Treatment with saline or ozone began on the day of the nerve crush. Left facial nerve stimulation thresholds were measured before crush, immediately after crush, and after 30 days. After measuring nerve stimulation thresholds at 30 days post-injury, the crushed facial nerve was excised. All specimens were studied using light and electron microscopy. Post-crushing, the ozone-treated group had lower stimulation thresholds than the saline group. Although this did not achieve statistical significance, it is indicative of greater functional improvement in the ozone group. Significant differences were found in vascular congestion, macrovacuolization, and myelin thickness between the ozone and control groups. Significant differences were also found in axonal degeneration and myelin ultrastructure between the two groups. We found that ozone therapy exerted beneficial effect on the regeneration of crushed facial nerves in rats. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

PCA as a practical indicator of OPLS-DA model reliability.

PubMed

Worley, Bradley; Powers, Robert

Principal Component Analysis (PCA) and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) are powerful statistical modeling tools that provide insights into separations between experimental groups based on high-dimensional spectral measurements from NMR, MS or other analytical instrumentation. However, when used without validation, these tools may lead investigators to statistically unreliable conclusions. This danger is especially real for Partial Least Squares (PLS) and OPLS, which aggressively force separations between experimental groups. As a result, OPLS-DA is often used as an alternative method when PCA fails to expose group separation, but this practice is highly dangerous. Without rigorous validation, OPLS-DA can easily yield statistically unreliable group separation. A Monte Carlo analysis of PCA group separations and OPLS-DA cross-validation metrics was performed on NMR datasets with statistically significant separations in scores-space. A linearly increasing amount of Gaussian noise was added to each data matrix followed by the construction and validation of PCA and OPLS-DA models. With increasing added noise, the PCA scores-space distance between groups rapidly decreased and the OPLS-DA cross-validation statistics simultaneously deteriorated. A decrease in correlation between the estimated loadings (added noise) and the true (original) loadings was also observed. While the validity of the OPLS-DA model diminished with increasing added noise, the group separation in scores-space remained basically unaffected. Supported by the results of Monte Carlo analyses of PCA group separations and OPLS-DA cross-validation metrics, we provide practical guidelines and cross-validatory recommendations for reliable inference from PCA and OPLS-DA models.

'Change4Life Smart Swaps': quasi-experimental evaluation of a natural experiment.

PubMed

Wrieden, Wendy L; Levy, Louis B

2016-09-01

To evaluate the impact on food purchasing behaviour of the 'Change4Life Smart Swaps' campaign to encourage families to make small changes to lower-fat or lower-sugar versions of commonly eaten foods and drinks. Quasi-experimental study comparing the proportion of swaps made by an intervention group (267 families who had signed up to the 'Smart Swaps' campaign promoted through various media, including television and radio advertising in early 2014) and a comparison group (135 families resident in Wales, signed up for 'Change4Life' materials, but not directly exposed to the 'Smart Swaps' campaign). During weeks 1, 2 and 3 of the campaign participants were asked to record their purchases of dairy products, carbonated drinks and breakfast cereals, using a mobile phone app questionnaire, when making a purchase within the category. England and Wales. Families registered with 'Change4Life'. In weeks 2 and 3 a significantly higher percentage of the intervention group had made 'smart swaps' than the comparison group. After week 3, 58 % of participants had swapped to a lower-fat dairy product compared with 26 % of the comparison group (P<0·001), 32 % of the intervention group had purchased a lower-sugar drink compared with 19 % of the comparison group (P=0·01), and 24 % had made a change to a lower-sugar cereal compared with 12 % of the comparison group (P=0·009). In the short term a national campaign to change purchase habits towards healthier products may have some merit but the sustainability of change requires further investigation.

Impact of 900 MHz electromagnetic field exposure on main male reproductive hormone levels: a Rattus norvegicus model

NASA Astrophysics Data System (ADS)

Sepehrimanesh, Masood; Saeb, Mehdi; Nazifi, Saeed; Kazemipour, Nasrin; Jelodar, Gholamali; Saeb, Saeedeh

2014-09-01

This work analyzes the effects of radiofrequency-electromagnetic field (RF-EMF) exposure on the reproductive system of male rats, assessed by measuring circulating levels of FSH, LH, inhibin B, activin B, prolactin, and testosterone. Twenty adult male Sprague-Dawley rats (180 ± 10 g) were exposed to 900 MHz RF-EMF in four equal separated groups. The duration of exposure was 1, 2, and 4 h/day over a period of 30 days and sham-exposed animals were kept under the same environmental conditions as the exposed group except with no RF-EMF exposure. Before the exposure, at 15 and 30 days of exposure, determination of the abovementioned hormone levels was performed using ELISA. At the end of the experiment, FSH and LH values of the long time exposure (LTE) group were significantly higher than the sham-exposed group ( p < 0.05). Serum activin B and prolactin in the LTE group showed significant increase and inhibin B showed significant decrease than sham and short time exposed (STE) groups after 30 days RF-EMF exposure ( p < 0.05). Also, a significant decrease in serum testosterone levels in the LTE group was found compared to short and moderate time exposed (MTE) groups after 30 days RF-EMF exposure ( p < 0.05). Results suggest that reproductive hormone levels are disturbed as a result of RF-EMF exposure and it may possibly affect reproductive functions. However, testosterone and inhibin B concentrations as a fertility marker and spermatogenesis were decreased significantly.