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Sample records for experimentally induced dyspnea

  1. Interactions Between Dyspnea and the Brain Processing of Nociceptive Stimuli: Experimental Air Hunger Attenuates Laser-Evoked Brain Potentials in Humans

    PubMed Central

    Dangers, Laurence; Laviolette, Louis; Similowski, Thomas; Morélot-Panzini, Capucine

    2015-01-01

    Dyspnea and pain share several characteristics and certain neural networks and interact with each other. Dyspnea-pain counter-irritation consists of attenuation of preexisting pain by intercurrent dyspnea and has been shown to have neurophysiological correlates in the form of inhibition of the nociceptive spinal reflex RIII and laser-evoked potentials (LEPs). Experimentally induced exertional dyspnea inhibits RIII and LEPs, while “air hunger” dyspnea does not inhibit RIII despite its documented analgesic effects. We hypothesized that air hunger may act centrally and inhibit LEPs. LEPs were obtained in 12 healthy volunteers (age: 21–29) during spontaneous breathing (FB), ventilator-controlled breathing (VC) tailored to FB, after inducing air hunger by increasing the inspired fraction of carbon dioxide -FiCO2- (VCCO2), and during ventilator-controlled breathing recovery (VCR). VCCO2 induced intense dyspnea (visual analog scale = 63% ± 6% of full scale, p < 0.001 vs. VC), predominantly of the air hunger type. VC alone reduced the amplitude of the N2-P2 component of LEPs (Δ = 24.0% ± 21.1%, p < 0.05, effect-size = 0.74) predominantly through a reduction in P2, and the amplitude of this inhibition was further reduced by inducting air hunger (Δ = 22.6% ± 17.9%, p < 0.05, effect-size = 0.53), predominantly through a reduction in N2. Somatosensory-evoked potentials (SEPs) were not affected by VC or VCCO2, suggesting that the observed effects are specific to pain transmission. We conclude that air hunger interferes with the cortical mechanisms responsible for the cortical response to painful laser skin stimulation, which provides a neurophysiological substrate to the central nature of its otherwise documented analgesic effects. PMID:26648875

  2. [Child dyspnea].

    PubMed

    Levieux, Karine; Bihouée, Tiphaine

    2015-05-01

    The management of children dyspnea depends on the severity and symptomatology. The severity assessment requires knowledge of the standards of respiratory rate by age and signs of failure ventilatory mechanics. Recognize the time of dyspnea is important because it guides the diagnosis. Inspiratory dyspnea is most often due to viral laryngitis but an age of less than 6 months or no vaccination against Haemophilus should suggest other urgent diagnostics. Dyspnea with inspiratory and expiratory wheeze is a sign of tracheal damage and needs specialized hospital care. Expiratory dyspnea is the sign of a lower airway affection. A first episode of wheezing during epidemics sign acute bronchiolitis whose support is purely symptomatic with DRP and nutritional splitting. Corticosteroids, bronchodilators and chest physiotherapy are not indicated. Asthma attack is defined as a third episode of wheezing, that requires the administration of salbutamol with an inhalation room, and even oral corticosteroids. Febrile dyspnea must seek auscultatory or radiological abnormalities confirming pneumonia to be treated by a probabilistic and emergency antibiotherapy. PMID:26165098

  3. A 45-Year-Old Man With Recurrent Dyspnea and Hemoptysis during Exercise: Exercise-Induced Pulmonary Hemorrhage/Edema

    PubMed Central

    Kim, Dae Sung; Lee, Minhyeok; Kwon, Oh Jung; Jeong, Inbeom; Son, Ji Woong; Na, Moon Jun

    2015-01-01

    A 45-year-old man presented with dyspnea and hemoptysis during exercise. A chest computed tomography (CT) revealed multifocal diffuse patchy ground glass opacity and interlobular septal thickening in both the lungs. Permeability pulmonary edema or pulmonary hemorrhage was suspected. Serologic studies for autoimmune disorders and vasculitis were negative. There was no laboratory evidence of coagulopathy, other hematopoietic disease or infectious disease. Considering correlation with exercise, we diagnosed exercise-induced pulmonary hemorrhage (EIPH) or exercise-induced pulmonary edema (EIPE). The patient was managed with antifibrinolytics, antibiotics, and antitussive agent. After a week, follow-up chest CT revealed completely resolved pulmonary hemorrhage. About 2 months after the first event, he visited again with dyspnea and hemoptysis during running. In the present study, we report a case of recurrent pulmonary hemorrhage after exercise. PMID:26508928

  4. Comparing dynamic hyperinflation and associated dyspnea induced by metronome-paced tachypnea versus incremental exercise.

    PubMed

    Calligaro, Gregory L; Raine, Richard I; Bateman, Mary E; Bateman, Eric D; Cooper, Christopher B

    2014-02-01

    Dynamic hyperinflation (DH) during exercise is associated with both dyspnea and exercise limitation in COPD. Metronome-paced tachypnoea (MPT) is a simple alternative for studying DH. We compared MPT with exercise testing (XT) as methods of provoking DH, and assessed their relationship with dyspnea. We studied 24 patients with moderate COPD (FEV1 59 ± 9% predicted) after inhalation of ipratropium/salbutamol combination or placebo in a double-blind, crossover design. Inspiratory capacity (IC) was measured at baseline and after 30 seconds of MPT with breathing frequencies (fR) of 20, 30 and 40 breaths/min and metronome-defined I:E ratios of 1:1 and 1:2, in random sequence, followed by incremental cycle ergometry with interval determinations of IC. DH was defined as a decline in IC from baseline (∆IC) for both methods. Dyspnea was assessed using a Borg CR-10 scale. ∆IC during MPT was greater with higher fR and I:E ratio of 1:1 versus 1:2, and less when patients were treated with bronchodilator rather than placebo (P = 0.032). DH occurred during 19 (40%) XTs, and during 35 (73%) tests using MPT. Eleven of 18 (61%) non-congruent XTs (where DH occurred on MPT but not XT) terminated before fR of 40 breaths/min was reached. Although greater during XT, the intensity of dyspnea bore no relationship to DH during either MPT and XT. MPT at 40 breaths/min and I:E of 1:1 elicits the greatest ∆IC, and is a more sensitive method for demonstrating DH. The relationship between DH and dyspnea is complex and not determined by DH alone. PMID:24152211

  5. Daily activities are sufficient to induce dynamic pulmonary hyperinflation and dyspnea in chronic obstructive pulmonary disease patients

    PubMed Central

    Castro, Antonio A.M.; Kümpel, Claudia; Rangueri, Rosana Chaves; Oliveira, Maurício Dalcin; Dornelles, Rodrigo Alves; Brito, Emerson Roberto; Seki, Tânia Maria; Porto, Elias F

    2012-01-01

    OBJECTIVE: The aim of this study was to measure dynamic lung hyperinflation and its influence on dyspnea perception in moderate and severe chronic obstructive pulmonary disease patients after performing activities of daily living. METHODS: We measured inspiratory capacity, sensation of dyspnea, peripheral oxygen saturation, heart rate and respiratory rate in 19 chronic obstructive pulmonary disease patients. These measurements were taken at rest and after performing activities of daily living (e.g., going up and down a set of stairs, going up and down a ramp and sweeping and mopping a room). RESULT: The inspiratory capacity of patients at rest was significantly decreased compared to the capacity of patients after performing activities. The change in inspiratory capacity was -0.67 L after going up and down a ramp, -0.46 L after sweeping and mopping a room, and -0.55 L after climbing up and down a set of stairs. Dyspnea perception increased significantly between rest, sweeping and mopping, and going up and down a set of stairs. Dyspnea perception correlated positively with inspiratory capacity variation (r = 0.85) and respiratory rate (r = 0.37) and negatively with peripheral oxygen saturation (r = -0.28). CONCLUSION: Chronic obstructive pulmonary disease patients exhibited reductions in inspiratory capacity and increases in dyspnea perception during commonly performed activities of daily living, which may limit physical performance in these patients. PMID:22522756

  6. THE MULTIPLE DIMENSIONS OF DYSPNEA: REVIEW AND HYPOTHESES

    PubMed Central

    Lansing, Robert W; Gracely, Richard H; Banzett, Robert B

    2009-01-01

    Although dyspnea is a common and troubling symptom, our understanding of the neurophysiology of dyspnea is woefully incomplete. Most measurements of dyspnea treat it as a single entity. Although the multidimensional dyspnea concept has been mentioned for many decades, only recently has the concept been the subject of experimental tests. Emerging evidence has begun to favor the hypothesis that dyspnea comprises multiple dimensions or components that can be measured as different entities. Most recently, studies have begun to show that there is a separable ‘affective dimension’ (i.e., unpleasantness and emotional impact). Understanding of the multidimensional measurement of pain is far in advance of dyspnea, and has enabled progress in the neurophysiology of pain, including identification of separate neural structures subserving various elements of pain perception. We propose here a multidimensional model of dyspnea based on a state-of-the-art pain model, and review existing evidence in the light of this model. PMID:18706531

  7. Evaluation of chronic dyspnea.

    PubMed

    Karnani, Neel G; Reisfield, Gary M; Wilson, George R

    2005-04-15

    Chronic dyspnea is defined as dyspnea lasting more than one month. In approximately two thirds of patients presenting with dyspnea, the underlying cause is cardiopulmonary disease. Establishing an accurate diagnosis is essential because treatment differs depending on the underlying condition. Asthma, congestive heart failure, chronic obstructive pulmonary disease, pneumonia, cardiac ischemia, interstitial lung disease, and psychogenic causes account for 85 percent of patients with this principal symptom. The history and physical examination should guide selection of initial diagnostic tests such as electrocardiogram, chest radiograph, pulse oximetry, spirometry, complete blood count, and metabolic panel. If these are inconclusive, additional testing is indicated. Formal pulmonary function testing may be needed to establish a diagnosis of asthma, chronic obstructive pulmonary disease, or interstitial lung disease. High-resolution computed tomography is particularly useful for diagnosing interstitial lung disease, idiopathic pulmonary fibrosis, bronchiectasis, or pulmonary embolism. Echocardiography and brain natriuretic peptide levels help establish a diagnosis of congestive heart failure. If the diagnosis remains unclear, additional tests may be required. These include ventilation perfusion scans, Holter monitoring, cardiac catheterization, esophageal pH monitoring, lung biopsy, and cardiopulmonary exercise testing. PMID:15864893

  8. Positive emotion reduces dyspnea during slow paced breathing.

    PubMed

    Allen, Ben; Friedman, Bruce H

    2012-05-01

    Slow breathing is used to induce cardiovascular resonance, a state associated with health benefits, but it can also increase tidal volume and associated dyspnea (respiratory discomfort). Dyspnea may be decreased by induced positive affect. In this study, 71 subjects (36 men, M = 20 years) breathed at 6 breaths per min. In condition one, subjects paced their breathing by inhaling and exhaling as a vertical bar moved up and down. In condition two, breathing was paced by a timed slideshow of positive images; subjects inhaled during a black screen and exhaled as the image appeared. Cardiac, respiratory, and self-reported dyspnea and emotional indices were recorded. Tidal volume and the intensity and unpleasantness of dyspnea were reduced when paced breathing was combined with pleasant images. These results show that positive affect can reduce dyspnea during slow paced breathing, and may have applications for induced cardiovascular resonance. PMID:22292794

  9. Hospital without dyspnea: rationale and design of a multidisciplinary intervention.

    PubMed

    Vicent, Lourdes; Olarte, Juan Manuel Nuñez; Puente-Maestu, Luis; Artajona, Esther; Fernández-Avilés, Francisco; Martínez-Sellés, Manuel

    2016-07-01

    Dyspnea is a common and disabling symptom of respiratory and heart diseases, which is growing in incidence. During hospital admission, breathlessness is under-diagnosed and under-treated, although there are treatments available for controlling the symptom. We have developed a tailored implementation strategy directed to medical staff to promote the application of these pharmacological and non-pharmacological tools in dealing with dyspnea. The primary aim is to decrease the rate of patients that do not receive an adequate relief of dyspnea. This is a four-stage quasi-experimental study. The intervention consists in two teaching talks that will be taught in Cardiology and Respiratory Medicine Departments. The contents will be prepared by Palliative Care specialists, based on available tools for management of dyspnea and patients' needs. A cross-sectional study of dyspnea in hospitalized patients will be performed before and after the intervention to ascertain an improvement in dyspnea intensity due to changes in medical practices. The last phase consists in the creation of consensus protocols for dyspnea management based in our experience. The results of this study are expected to be of great value and may change clinical practice in the near future and promote a changing for the better of dyspnea care. PMID:27605944

  10. Hospital without dyspnea: rationale and design of a multidisciplinary intervention

    PubMed Central

    Vicent, Lourdes; Olarte, Juan Manuel Nuñez; Puente-Maestu, Luis; Artajona, Esther; Fernández-Avilés, Francisco; Martínez-Sellés, Manuel

    2016-01-01

    Dyspnea is a common and disabling symptom of respiratory and heart diseases, which is growing in incidence. During hospital admission, breathlessness is under-diagnosed and under-treated, although there are treatments available for controlling the symptom. We have developed a tailored implementation strategy directed to medical staff to promote the application of these pharmacological and non-pharmacological tools in dealing with dyspnea. The primary aim is to decrease the rate of patients that do not receive an adequate relief of dyspnea. This is a four-stage quasi-experimental study. The intervention consists in two teaching talks that will be taught in Cardiology and Respiratory Medicine Departments. The contents will be prepared by Palliative Care specialists, based on available tools for management of dyspnea and patients' needs. A cross-sectional study of dyspnea in hospitalized patients will be performed before and after the intervention to ascertain an improvement in dyspnea intensity due to changes in medical practices. The last phase consists in the creation of consensus protocols for dyspnea management based in our experience. The results of this study are expected to be of great value and may change clinical practice in the near future and promote a changing for the better of dyspnea care. PMID:27605944

  11. ASSESSMENT OF DYSPNEA IN ASTHMA: VALIDATION OF THE DYSPNEA-12

    PubMed Central

    Yorke, Janelle; Russell, Anne-Marie; Swigris, Jeff; Shuldham, Caroline; Haigh, Carol; Rochnia, Nikki; Hoyle, Jennifer; Jones, Paul W

    2011-01-01

    Background Dyspnea is a prominent symptom in asthma. The Dyspnea-12 (D-12), an instrument that quantifies breathlessness using 12 descriptors that tap the physical and affective aspects, has shown promise for the measurement of dyspnea in cardiorespiratory disease. Objective We report the results of a study designed to test the validity and reliability of the D-12 in a population of patients with asthma. Methods This cross-sectional study included 102 patients with asthma. Subjects completed the D-12, Hospital Anxiety and Depression Scale (HAD), St George’s Respiratory Questionnaire (SGRQ), MRC scale. Confirmatory factor analysis confirmed the two-component structure of the D-12 (i.e. 7 items that tap the Physical aspects of breathlessness and 5 items that tap the Affective aspects). Results The D-12 subscales had excellent internal reliability (Cronbach’s alpha for the ‘Physical’ score was 0.94 and the Affective score was 0.95). The D-12 Physical component was more strongly correlated with SGRQ Symptoms (r = 0.648), SGRQ Activities (r = 0.635) and MRC grade (r = 0.636), while the Affective component was more strongly correlated with SGRQ Impacts (r = 0.765) and HAD scores (anxiety r = 0.641 and depression r = 0.602). Conclusion This study supports validity of the D-12 for use in the assessment of dyspnea of patients with asthma. It assesses one of the most pertinent symptoms of asthma from two viewpoints -physical and affective. PMID:21635136

  12. Acute dyspnea in the office.

    PubMed

    Zoorob, Roger J; Campbell, James S

    2003-11-01

    Respiratory difficulty is a common presenting complaint in the outpatient primary care setting. Because patients may first seek care by calling their physician's office, telephone triage plays a role in the early management of dyspnea. Once the patient is in the office, the initial goal of assessment is to determine the severity of the dyspnea with respect to the need for oxygenation and intubation. Unstable patients typically present with abnormal vital signs, altered mental status, hypoxia, or unstable arrhythmia, and require supplemental oxygen, intravenous access and, possibly, intubation. Subsequent management depends on the differential diagnosis established by a proper history, physical examination, and ancillary studies. Dyspnea is most commonly caused by respiratory and cardiac disorders. Other causes may be upper airway obstruction, metabolic acidosis, a psychogenic disorder, or a neuromuscular condition. Differential diagnoses in children include bronchiolitis, croup, epiglottitis, and foreign body aspiration. Pertinent history findings include cough, sore throat, chest pain, edema, and orthopnea. The physical examination should focus on vital signs and the heart, lungs, neck, and lower extremities. Significant physical signs are fever, rales, wheezing, cyanosis, stridor, or absent breath sounds. Diagnostic work-up includes pulse oximetry, complete blood count, electrocardiography, and chest radiography. If the patient is admitted to the emergency department or hospital, blood gases, ventilation-perfusion scan, D-dimer tests, and spiral computed tomography can help clarify the diagnosis. In a stable patient, management depends on the underlying etiology of the dyspnea. PMID:14620600

  13. Routine dyspnea assessment on unit admission.

    PubMed

    Baker, Kathy; Barsamian, Jennifer; Leone, Danielle; Donovan, Barbara C; Williams, Donna; Carnevale, Kerry; Lansing, Robert; Banzett, Robert

    2013-11-01

    Dyspnea assessment is valuable in diagnosis, prognosis, symptom management, and targeted intervention, and in the allotment and management of patient care resources. The assessment of dyspnea, like that of pain, depends on patient self-report. Expert consensus panels have called for dyspnea to be measured quantitatively and documented on a routine basis, as is the practice with pain. But little information is available on how to measure and record dyspnea ratings systematically. Consequently, the prevalence of dyspnea in hospital settings may be greater than is generally recognized, and dyspnea may be insufficiently managed. This article describes a pilot study that sought to test the feasibility of measuring dyspnea as part of the initial patient assessment performed by nurses within several inpatient units of a large urban hospital. PMID:24113531

  14. Dyspnea in the ventilator-assisted patient.

    PubMed

    Lush, M T; Janson-Bjerklie, S; Carrieri, V K; Lovejoy, N

    1988-09-01

    Our purpose in this study was to investigate the factors coincident with the occurrence of dyspnea in ventilator-assisted patients. Five alert and oriented patients with pulmonary disease that was restrictive, obstructive, or both, who were receiving mechanical ventilation, participated in this descriptive study. At 4-hour intervals and at complaint of dyspnea, patients quantified the severity of their dyspnea using the visual analogue and modified Borg scales. At each measurement of dyspnea, nurses observed concomitant physiologic and environmental variables. A moderate correlation (r = 0.51, p less than 0.001) was found between the number of events and activities occurring in the intensive care unit environment and the occurrence and severity of dyspnea. The visual analogue scale and modified Borg scale measures of dyspnea were highly correlated (r = 0.92, p less than 0.001) and may be useful tools for assessing dyspnea in patients undergoing mechanical ventilation. PMID:3417463

  15. An approach to dyspnea in advanced disease.

    PubMed Central

    Gallagher, Romayne

    2003-01-01

    INTRODUCTION: To describe an approach to assessment and treatment of dyspnea. SOURCES OF INFORMATION: New level I evidence can guide management of dyspnea in advanced illness. Assessment and use of adjuvant medications and oxygen relies on level II and III evidence. MAIN MESSAGE: Opioids are first-line therapy for managing dyspnea in advanced illness. They are safe and effective in reducing shortness of breath. Neuroleptics are useful adjuvant medications. Evidence does not support use of oxygen for every patient experiencing dyspnea; it should be tried for patients who do not benefit from first-line medications and nonmedicinal therapies. CONCLUSION: Opioids relieve dyspnea and are indicated as first-line treatment for dyspnea arising from advanced disease of any cause. PMID:14708926

  16. The palliation of dyspnea in terminal disease.

    PubMed

    Zeppetella, G

    1998-01-01

    Dyspnea is a complex subjective experience that is common in terminal illness. Patients may present at any time during the course of their illness, although prevalence increases with disease progression. Dyspnea has physical, psychological, social and spiritual components; without recognizing how each of these contributes to the total suffering of dyspnea, management is unlikely to be successful. The management of dyspnea involves both pharmacological and non-pharmacological treatment. The main pharmacological palliative treatments are oxygen, opioids, and benzodiazepines, but the evidence to support these treatments is limited. More research is urgently needed to establish the efficacy of current treatments and to identify new ones. PMID:9866455

  17. Approach to Adult Patients with Acute Dyspnea.

    PubMed

    DeVos, Elizabeth; Jacobson, Lisa

    2016-02-01

    Undifferentiated patients in respiratory distress require immediate attention in the emergency department. Using a thorough history and clinical examination, clinicians can determine the most likely causes of dyspnea. Understanding the pathophysiology of the most common diseases contributing to dyspnea guides rational testing and informed, expedited treatment decisions. PMID:26614245

  18. Predictors of dyspnea prevalence: Results from the BOLD study

    PubMed Central

    Grønseth, Rune; Vollmer, William M.; Hardie, Jon A.; Ólafsdóttir, Inga Sif; Lamprecht, Bernd; Buist, A. Sonia; Gnatiuc, Louisa; Gulsvik, Amund; Johannessen, Ane; Enright, Paul

    2014-01-01

    Dyspnea is a cardinal symptom for cardiorespiratory diseases. No study has assessed worldwide variation in dyspnea prevalence or predictors of dyspnea. We used cross-sectional data from population-based samples in 15 countries of the BOLD study to estimate prevalence of dyspnea in the full sample as well as in an a priori defined low-risk group (few risk factors or dyspnea-associated diseases). Dyspnea was defined by the modified Medical Research Council questions. We used ordered logistic regression analysis to study the association of dyspnea with site, sex, age, education, smoking habits, low/high BMI, self-reported disease, and spirometry results. Of the 9,484 participants, 27% reported any dyspnea. In the low-risk subsample (N=4,329), 16% reported some dyspnea. In multivariate analyses, all covariates were correlated to dyspnea, but only 13% of dyspnea variation was explained. Women reported more dyspnea than men (odds ratio ≈ 2.1). When forced vital capacity (FVC) fell below 60% of predicted, dyspnea was much more likely. There was considerable geographical variation in dyspnea, even when we adjusted for known risk factors and spirometry results. We were only able to explain 13% of dyspnea variation. PMID:24176991

  19. Is dyspnea management evidence-based?

    PubMed

    Aiello-Laws, Lisa B

    2013-11-01

    Reviewing the articles published in the past 40 years in the Oncology Nursing Forum (ONF) can assist in the identification of trends related to lung cancer treatment and management. Fifty-eight articles or studies published in ONF during that time were specific to lung cancer. The total number of published articles increased with each decade, but no articles were identified in the 1970s. The topics were quite varied, with each of the following represented by three or more articles: symptom clusters, radiation, smoking cessation, dyspnea, nutrition, and quality of life. To better focus this review on a specific aspect of lung cancer management, dyspnea was chosen. PMID:24161629

  20. Speaking-Related Dyspnea in Healthy Adults

    ERIC Educational Resources Information Center

    Hoit, Jeannette D.; Lansing, Robert W.; Perona, Kristen E.

    2007-01-01

    Purpose: To reveal the qualities and intensity of speaking-related dyspnea in healthy adults under conditions of high ventilatory drive, in which the behavioral and metabolic control of breathing must compete. Method: Eleven adults read aloud while breathing different levels of inspired carbon dioxide (CO[subscript 2]). After the highest level,…

  1. Mechanical correlates of dyspnea in bronchial asthma.

    PubMed

    Antonelli, Andrea; Crimi, Emanuele; Gobbi, Alessandro; Torchio, Roberto; Gulotta, Carlo; Dellaca, Raffaele; Scano, Giorgio; Brusasco, Vito; Pellegrino, Riccardo

    2013-12-01

    We hypothesized that dyspnea and its descriptors, that is, chest tightness, inspiratory effort, unrewarded inspiration, and expiratory difficulty in asthma reflect different mechanisms of airflow obstruction and their perception varies with the severity of bronchoconstriction. Eighty-three asthmatics were studied before and after inhalation of methacholine doses decreasing the 1-sec forced expiratory volume by ~15% (mild bronchoconstriction) and ~25% (moderate bronchoconstriction). Symptoms were examined as a function of changes in lung mechanics. Dyspnea increased with the severity of obstruction, mostly because of inspiratory effort and chest tightness. At mild bronchoconstriction, multivariate analysis showed that dyspnea was related to the increase in inspiratory resistance at 5 Hz (R 5) (r (2) = 0.10, P = 0.004), chest tightness to the decrease in maximal flow at 40% of control forced vital capacity, and the increase in R 5 at full lung inflation (r (2) = 0.15, P = 0.006), inspiratory effort to the temporal variability in R 5-19 (r (2) = 0.13, P = 0.003), and unrewarded inspiration to the recovery of R 5 after deep breath (r (2) = 0.07, P = 0.01). At moderate bronchoconstriction, multivariate analysis showed that dyspnea and inspiratory effort were related to the increase in temporal variability in inspiratory reactance at 5 Hz (X 5) (r (2) = 0.12, P = 0.04 and r (2) = 0.18, P < 0.001, respectively), and unrewarded inspiration to the decrease in X 5 at maximum lung inflation (r (2) = 0.07, P = 0.04). We conclude that symptom perception is partly explained by indexes of airway narrowing and loss of bronchodilatation with deep breath at low levels of bronchoconstriction, but by markers of ventilation heterogeneity and lung volume recruitment when bronchoconstriction becomes more severe. PMID:24744853

  2. Mechanical correlates of dyspnea in bronchial asthma

    PubMed Central

    Antonelli, Andrea; Crimi, Emanuele; Gobbi, Alessandro; Torchio, Roberto; Gulotta, Carlo; Dellaca, Raffaele; Scano, Giorgio; Brusasco, Vito; Pellegrino, Riccardo

    2013-01-01

    Abstract We hypothesized that dyspnea and its descriptors, that is, chest tightness, inspiratory effort, unrewarded inspiration, and expiratory difficulty in asthma reflect different mechanisms of airflow obstruction and their perception varies with the severity of bronchoconstriction. Eighty‐three asthmatics were studied before and after inhalation of methacholine doses decreasing the 1‐sec forced expiratory volume by ~15% (mild bronchoconstriction) and ~25% (moderate bronchoconstriction). Symptoms were examined as a function of changes in lung mechanics. Dyspnea increased with the severity of obstruction, mostly because of inspiratory effort and chest tightness. At mild bronchoconstriction, multivariate analysis showed that dyspnea was related to the increase in inspiratory resistance at 5 Hz (R5) (r2 = 0.10, P = 0.004), chest tightness to the decrease in maximal flow at 40% of control forced vital capacity, and the increase in R5 at full lung inflation (r2 = 0.15, P = 0.006), inspiratory effort to the temporal variability in R5‐19 (r2 = 0.13, P = 0.003), and unrewarded inspiration to the recovery of R5 after deep breath (r2 = 0.07, P = 0.01). At moderate bronchoconstriction, multivariate analysis showed that dyspnea and inspiratory effort were related to the increase in temporal variability in inspiratory reactance at 5 Hz (X5) (r2 = 0.12, P = 0.04 and r2 = 0.18, P < 0.001, respectively), and unrewarded inspiration to the decrease in X5 at maximum lung inflation (r2 = 0.07, P = 0.04). We conclude that symptom perception is partly explained by indexes of airway narrowing and loss of bronchodilatation with deep breath at low levels of bronchoconstriction, but by markers of ventilation heterogeneity and lung volume recruitment when bronchoconstriction becomes more severe. PMID:24744853

  3. Sex differences in exertional dyspnea in patients with mild COPD: physiological mechanisms.

    PubMed

    Guenette, Jordan A; Jensen, Dennis; Webb, Katherine A; Ofir, Dror; Raghavan, Natya; O'Donnell, Denis E

    2011-08-15

    The purpose of this study was to evaluate the physiological basis for sex-differences in exercise-induced dyspnea in patients with mild COPD. We compared operating lung volumes, breathing pattern and dyspnea during incremental cycling in 32 men (FEV(1)=86±10% predicted) and women (FEV(1)=86±12% predicted) with mild COPD and 32 age-matched controls. There were no sex differences in dyspnea in the control group at any work-rate or ventilation (V(E)). Women with COPD had significantly greater dyspnea than men at 60 and 80 W. At 80 W, dyspnea ratings were 5.7±2.3 and 3.3±2.5 Borg units (P<0.05) and the V(E) to maximal ventilatory capacity ratio was 72% and 55% in women and men, respectively (P<0.05). Comparable increases in dynamic hyperinflation were seen in both male and female COPD groups at symptom limitation but women reached tidal volume constraints at a lower work rate and V(E) than men. Superimposing mild COPD on the normal aging effects had greater sensory consequences in women because of their naturally reduced ventilatory reserve. PMID:21524719

  4. Dyspnea due to pulmonary vessel arteritis

    PubMed Central

    Gilmour, Suzana M; Dominelli, Giulio S; Leipsic, Jonathon A; Levy, Robert D

    2014-01-01

    Pulmonary arteritis is a rare cause of pulmonary hypertension. Causes of pulmonary arteritis can be divided into primary and secondary, as well as classified according to vessel size. Only large vessel vasculitis is associated with pulmonary hypertension; primary forms include Takayasu arteritis and giant cell arteritis. The diagnosis of pulmonary arteritis can be challenging and the associated morbidity is serious without prompt, directed treatment. The authors present a case involving a 48-year-old First Nations man presenting with a six-month history of exertional dyspnea and severe stenosis of the left pulmonary artery, who was ultimately diagnosed with pulmonary arteritis related to large vessel vasculitis. PMID:24524110

  5. [A rare cause of dyspnea on exertion].

    PubMed

    Maccari, Uberto; Rosini, Costanza F; Scala, Raffaele; Magnolfi, Anna Lisa; Felici, Massimo; Bolognese, Leonardo

    2016-01-01

    Vascular rings are rare anomalies accounting for 1% to 3% of all congenital heart diseases with a similar frequency in both sexes, which can result in a variable degree of extrinsic compression of the trachea and esophagus. We report the case of a 46-year-old woman with symptomatic dyspnea and double aortic arch that caused esophageal tracheal compression. Considering the little impact of the functional vascular anomaly in our case, a conservative approach was adopted with clinical and functional annual follow-up. PMID:26901260

  6. [Definition, primary examination and differential diagnostics in acute dyspnea].

    PubMed

    Hüfner, A; Dodt, C

    2015-09-01

    The topic of acute dyspnea is presented in two separate articles. This first part deals with the definition and pathophysiology of dyspnea as well as important considerations on the history of the present illness, physical examination, initial therapy and differential diagnostic considerations. The second part covers relevant diagnostic investigations and principles for the initial management. The causes, consequences and perception of acute dyspnea can be very different. The adult patient with acute dyspnea presents difficult challenges in the diagnosis and management. The emergency clinician must work through a wide range of differential diagnostic considerations while providing appropriate initial treatment for a potentially life-threatening disease. PMID:26335293

  7. Induction of dyspnea evokes increased anxiety and maladaptive breathing in individuals with high anxiety sensitivity and suffocation fear.

    PubMed

    Alius, Manuela G; Pané-Farré, Christiane A; Von Leupoldt, Andreas; Hamm, Alfons O

    2013-05-01

    Although respiratory symptoms are relevant for diagnosis and etiology of panic disorder, anxiety responses and breathing behavior evoked by induction of dyspnea have rarely been studied. Therefore, dyspnea sensations and affective evaluations evoked by inspiratory resistive loads of different intensities were first assessed in 23 individuals with high versus 24 participants with low anxiety sensitivity (AS). High AS participants with high fear of suffocation rated loads of the same physical intensity as more unpleasant and reported more intense feelings of dyspnea and more respiratory and panic symptoms than low AS individuals. In the second experiment assessing physiological responses to physically comparable loads, high suffocation fear participants showed an increase in minute ventilation to compensate for fear-induced air hunger. This ventilation behavior results in increased frequency of dyspnea sensations, thus increasing fear of suffocation. PMID:23421426

  8. Dyspnea related to reversibly-binding P2Y12 inhibitors: A review of the pathophysiology, clinical presentation and diagnostics.

    PubMed

    Unverdorben, Martin; Parodi, Guido; Pistolesi, Massimo; Storey, Robert F

    2016-01-01

    Dyspnea is a common symptom physiologically associated with strenuous exercise and pathologically reflecting well-known diseases and conditions that are predominantly pulmonary, cardiovascular, and weight-related in origin. Dyspnea improves with appropriate measures that enhance physical performance and treatment of the underlying diseases. Dyspnea is less commonly triggered by other causes such as the environment (e.g., ozone), drugs, and others, some of which do not seem to affect bronchopulmonary function as evidenced by normal results of comprehensive pulmonary function testing. In cardiovascular medicine, dyspnea has recently attracted attention because it has been reported that this symptom occurs more frequently with the administration of the new oral reversibly-binding platelet P2Y12 receptor inhibitors ticagrelor [1-6], cangrelor [7-10], and elinogrel [11]. This paper succinctly addresses the current understanding of the pathophysiology, clinical presentation, and diagnostics of dyspnea, associated either with bronchopulmonary function impairment, as triggered mainly by pulmonary and cardiovascular diseases, or without bronchopulmonary function impairment, as induced by endogenous or external compounds such as drugs in order to provide a context for understanding, recognizing and managing P2Y12 inhibitor-induced dyspnea. PMID:26386945

  9. Giant Dermoid Cyst Causing Dysphagia and Dyspnea.

    PubMed

    Derin, Serhan; Koseoglu, Sabri; Sahan, Leyla; Dere, Yelda; Sahan, Murat

    2016-05-01

    Dermoid cysts are benign lesions seen in young adults. The second most common localization is the floor of the mouth. They are usually asymptomatic over years but can be symptomatic due to secondary changes or the size. Herein, we report a case of 19-year-old woman who applied to emergency service with dyspnea, dysphagia and enlarging of a mass in the submental region. The patient cannot be entubated because of the mass pushing the tongue base backward closing the laryngeal view. Elective tracheostomy was performed for providing airflow during the operation. After the operation a cystic mass fulfilled with keratin lined by keratinized stratified squamous epithelium in addition to the dermal appendages such as sweat glands and follicular structures were seen histopathologically and the case was diagnosed as dermoid cyst of the submental region. In such patients with quick enlarging of mass causing airway obstructions, the tracheostomy can be the preferable method because of the difficulties in entubation. PMID:26999700

  10. The Interpretation of Dyspnea in the Patient with Asthma

    PubMed Central

    Lavietes, Marc H.

    2015-01-01

    Physicians have noted dyspnea in severely ill asthmatic patients to be associated with fright or panic; in more stable patients dyspnea may reflect characteristics including lung function, personality and behavioral traits. This study evaluates the symptom of dyspnea in 32 asthmatic patients twice: first when acutely ill and again after an initial response to therapy. Spirometry was performed, dyspnea quantified (Borg scale), and panic assessed with a specialized measure of acute panic (the acute panic inventory (API)) in the 32 patients before and again after treatment. After treatment, questionnaires to evaluate somatization and panic disorder were also administered. When acutely ill, both the API and all spirometric measures (PEFR; FEV1; IC) correlated with dyspnea. Multiple linear regression showed that measures of the API, the peak expiratory flow rate, and female sex taken together accounted for 41% of dyspnea in acute asthma. After treatment, the API again predicted dyspnea while spirometric data did not. Those subjects who described themselves as having chronic panic disorder reported high grades of dyspnea after treatment also. We conclude that interpretations of the self-report of asthma differ between acutely ill and stable asthmatic patients. PMID:26819756

  11. Effects of bronchoconstriction and external resistive loading on the sensation of dyspnea.

    PubMed

    Taguchi, O; Kikuchi, Y; Hida, W; Iwase, N; Satoh, M; Chonan, T; Takishima, T

    1991-12-01

    To determine whether the intensity of dyspnea at a given level of respiratory motor output differs between bronchoconstriction and the presence of an external resistance, we compared the sensation of difficulty in breathing during isocapnic voluntary hyperventilation in six normal subjects. An external resistance of 1.9 cmH2O.1-1.s was applied during both inspiration and expiration. To induce bronchoconstriction, histamine aerosol (5 mg/ml) was inhaled until airway resistance (Raw) increased to a level approximately equal to the subject's control Raw plus the added external resistance. To clarify the role of vagal afferents on the genesis of dyspnea during both forms of obstruction to airflow, the effect of airway anesthesia by lidocaine aerosol inhalation was also examined after histamine and during external resistive loading. The sensation of difficulty in breathing was rated at 30-s intervals on a visual analog scale during isocapnic voluntary hyperpnea, in which the subjects were asked to copy an oscilloscope volume trace obtained previously during progressive hypercapnia. Histamine inhalation significantly increased the intensity of the dyspneic sensation over the equivalent external resistive load at the same levels of ventilation and occlusion pressure during voluntary hyperpnea. Inhaled lidocaine decreased the sensation of dyspnea during bronchoconstriction with no change in Raw, but it did not significantly change the sensation during external resistive loading. These results suggest that afferent vagal activity plays a role in the genesis of dyspnea during bronchoconstriction. PMID:1778911

  12. Opioids: an unexplored option for treatment of dyspnea in IPF

    PubMed Central

    Kohberg, Charlotte; Andersen, Charlotte Uggerhøj; Bendstrup, Elisabeth

    2016-01-01

    Background Idiopathic pulmonary fibrosis (IPF) is the most common among the idiopathic interstitial pneumonias and has the worst prognosis, with a median survival of 3–5 years. The most common symptom in IPF is dyspnea, impacting on the patient's quality of life and life expectancy. Morphine in the treatment of dyspnea has been investigated but with conflicting results. This review aims to clarify the role of opioids in the treatment of dyspnea in patients with IPF. Methods A literature search was performed using the MeSH and PubMed databases. As only very few studies included patients with IPF, studies conducted primarily with patients with chronic obstructive pulmonary disease were also included. In total, 14 articles were found. Results Seven studies reported use of systemic morphine and seven studies of inhaled morphine. Five of the seven studies investigating systemic administration detected an improvement in either dyspnea or exercise capacity, whereas no beneficial effect on dyspnea was detected in any study using inhaled morphine. No severe adverse effects such as respiratory depression were reported in any study, although constipation was reported as a notable adverse effect. Conclusions Results were inconsistent, but in some studies systemic morphine administration showed a significant improvement in the dyspnea score on a visual analog scale without observation of severe side effects. Nebulized morphine had no effect on dyspnea. PMID:26969472

  13. Experimental peritonitis induced by oral administration of indomethacin in Mongolian gerbils

    PubMed Central

    Lee, Jin-Uk

    2006-01-01

    The possibility of inducing peritoneal inflammation in three murine species (gerbils, rats and mice) via the oral administration of indomethacin was investigated with the overall aim of developing an experimental animal model for human peritonitis. Gerbils given high doses of indomethacin at a rate of 30 mg and 40 mg/kg body weight showed swelling of the abdomen, depression and dyspnea within 4 days after the treatment. The severity of the clinical symptoms increased with time. The animals were confirmed as having developed peritonitis based on the pathological features including inflammation of the peritoneum, and fibrinous adhesion of the abdominal organs in the abdominal cavity. The severity of peritonitis increased with increasing dose of indomethacin, and was not related to the gender of the animal. On the other hand, peritoneal inflammation did not develop in the rats and mice even at high doses. Therefore, the administration of 30 mg/kg body weight of indomethacin is an effective and simple method of inducing peritonitis in 5-week-old Mongolian gerbils. The animal peritonitis model used in this study can be used as an effective tool for examining potential therapeutic compounds for preventing peritoneal damage during peritonitis, and provide insight into the pathophysiology of peritonitis. PMID:16645338

  14. Incidence and causes of new-onset dyspnea in 3,719 patients treated with clopidogrel and aspirin combination after coronary stenting.

    PubMed

    Serebruany, Victor; Pokov, Ilya; Kuliczkowski, Wiktor; Vahabi, Javad; Atar, Dan

    2008-08-01

    The experimental oral antiplatelet agent AZD6140 causes dyspnea in randomized trials. Whether clopidogrel may also cause dyspnea remains controversial. We sought to define the incidence and causes of dyspnea in a large post-percutaneous coronary intervention (PCI) cohort based on open-labeled consecutive registry analysis of in-hospital charts and discharge diagnoses. Data were collected at six-month follow-up by means of telephone interviews or returned questionnaires during outpatient visits. Patients undergoing coronary stent implantation were loaded with 600 mg clopidogrel followed by 75 mg/daily in combination with 75-325 mg of aspirin daily for at least six months. Data from 3,719 patients were analyzed. Dyspnea was diagnosed in 157 (4.2%) patients caused by chronic obstructive pulmonary disease (n = 43 or 27% of the dyspnea group), heart failure (n = 30 or 19%), cancer (n = 22 or 14%), pneumonia (n = 17 or 11%); asthma (n = 8 or 5%), pulmonary hypertension (n = 8 or 5%); pericarditis (n = 5 or 3%); cardiac arrhythmias (n = 4 or 2.5%); pleural effusion (n = 1), pulmonary embolism (n = 1), anxiety (n = 1), or unknown (n = 17, or 11%). The incidence of dyspnea at six months in a post-stent cohort treated with aspirin and clopidogrel is low (4.2%). The majority of patients with dyspnea (140/157) exhibit a distinct underlying disease or condition, in contrast to only 17 patients (0.45% of total cohort) in whom the pathogenesis of dyspnea remained unidentified. These data closely match the frequency of dyspnea that was observed in the CAPRIE trial, suggesting that therapy with clopidogrel, and/or aspirin holds very small (if any) risk for dyspnea. PMID:18690353

  15. Idiopathic bilateral diaphragmatic dysfunction as a cause of dyspnea

    PubMed Central

    MacBruce, D; Safdar, S; Katpally, K; Shaaban, Hamid; Adelman, M

    2016-01-01

    Diaphragmatic paralysis is an unusual and often underrecognized cause of dyspnea. We present a case of bilateral diaphragmatic paralysis with no identifiable etiology. Our patient is a 73-year-old female with a history of smoking who presented with dyspnea and orthopnea. She was treated for obstructive lung disease with no improvement in dyspnea despite adequate therapy. She had pulmonary function tests (PFTs) that revealed marked decrease in vital capacity and was unable to perform lung volume maneuvers supine due to marked dyspnea. The maximal inspiratory pressure was 37 in the upright position and decreased to 27 in the supine position. She was given a presumptive diagnosis of idiopathic bilateral diaphragmatic dysfunction. Given the history, physical exam, and PFT findings, we felt that the patient did not need further invasive testing. The patient was treated with noninvasive mechanical ventilation due to hypercapnia and her symptoms improved. PMID:27186002

  16. Quantification of dyspnea confirmed by voice pitch analysis.

    PubMed

    Mohler, J G

    1982-01-01

    Previous efforts to quantitate dyspnea are reviewed. In this study, the voice was recorded at each level of exercise on 44 healthy male subjects exercised to maximum oxygen consumption (MVO2) by incremental treadmill testing. The fundamental frequency (FO) was compared to the physical changes noted during exercise associated with dyspnea at each level of oxygen uptake (VO2) and minute ventilation (VE). FO increased linearly with VO2 and VE. FO at MVO2 was about 1.66 times FO at rest; the slope of the increase was an individual characteristic. The sum of the graded signs of dyspnea codes (dyspnea sum index, DSI) also agreed with the measured voice changes, VO2, VE and the subjective assessment of dyspnea by the subject. Equations for predicting MVO2 from submaximal exercise are given which tested favorably against the actual MVO2. Because resting FO was most affected by anxiety, the equation predicting MVO2 from FO was not as reliable as from DSI. FO is a function of elastic properties of the vocal folds, which change in response to increased VE by permitting air to pass through "air shunts" of the arytenoid aperture. This creates a falsetto characteristic to the voice and is perceived as a stress quality. FO is a measurement reflecting many changes in the larynx with stress of exercise and perceived dyspnea. The laryngeal changes during exercise are reviewed, and the basis for the correlation between qualities of the voice and quantities such as FO are suggested. PMID:6927538

  17. Multidimensional Dyspnea Profile: an instrument for clinical and laboratory research

    PubMed Central

    O'Donnell, Carl R.; Guilfoyle, Tegan E.; Parshall, Mark B.; Schwartzstein, Richard M.; Meek, Paula M.; Gracely, Richard H.; Lansing, Robert W.

    2015-01-01

    There is growing awareness that dyspnoea, like pain, is a multidimensional experience, but measurement instruments have not kept pace. The Multidimensional Dyspnea Profile (MDP) assesses overall breathing discomfort, sensory qualities, and emotional responses in laboratory and clinical settings. Here we provide the MDP, review published evidence regarding its measurement properties and discuss its use and interpretation. The MDP assesses dyspnoea during a specific time or a particular activity (focus period) and is designed to examine individual items that are theoretically aligned with separate mechanisms. In contrast, other multidimensional dyspnoea scales assess recalled recent dyspnoea over a period of days using aggregate scores. Previous psychophysical and psychometric studies using the MDP show that: 1) subjects exposed to different laboratory stimuli could discriminate between air hunger and work/effort sensation, and found air hunger more unpleasant; 2) the MDP immediate unpleasantness scale (A1) was convergent with common dyspnoea scales; 3) in emergency department patients, two domains were distinguished (immediate perception, emotional response); 4) test–retest reliability over hours was high; 5) the instrument responded to opioid treatment of experimental dyspnoea and to clinical improvement; 6) convergent validity with common instruments was good; and 7) items responded differently from one another as predicted for multiple dimensions. PMID:25792641

  18. Does nebulized fentanyl relieve dyspnea during exercise in healthy man?

    PubMed

    Kotrach, Houssam G; Bourbeau, Jean; Jensen, Dennis

    2015-06-01

    Few therapies exist for the relief of dyspnea in restrictive lung disorders. Accumulating evidence suggests that nebulized opioids selective for the mu-receptor subtype may relieve dyspnea by modulating intrapulmonary opioid receptor activity. Our respective primary and secondary objectives were to test the hypothesis that nebulized fentanyl (a mu-opioid receptor agonist) relieves dyspnea during exercise in the presence of abnormal restrictive ventilatory constraints and to identify the physiological mechanisms of this improvement. In a randomized, double-blind, placebo-controlled crossover study, we examined the effect of 250 μg nebulized fentanyl, chest wall strapping (CWS), and their interaction on detailed physiological and perceptual responses to constant work rate cycle exercise (85% of maximum incremental work rate) in 14 healthy, fit young men. By design, CWS decreased vital capacity by ∼20% and mimicked the negative consequences of a mild restrictive lung disorder on exercise endurance time and on dyspnea, breathing pattern, dynamic operating lung volumes, and diaphragmatic electromyographic and respiratory muscle function during exercise. Compared with placebo under both unrestricted control and CWS conditions, nebulized fentanyl had no effect on exercise endurance time, integrated physiological response to exercise, sensory intensity, unpleasantness ratings of exertional dyspnea. Our results do not support a role for intrapulmonary opioids in the neuromodulation of exertional dyspnea in health nor do they provide a physiological rationale for the use of nebulized fentanyl in the management of dyspnea due to mild restrictive lung disorders, specifically those arising from abnormalities of the chest wall and not affiliated with airway inflammation. PMID:26031762

  19. Dyspnea-Related Cues Engage the Prefrontal Cortex

    PubMed Central

    Herigstad, Mari; Hayen, Anja; Evans, Eleanor; Hardinge, Frances M.; Davies, Robert J.; Wiech, Katja

    2015-01-01

    BACKGROUND: Dyspnea is the major source of disability in COPD. In COPD, environmental cues (eg, the prospect of having to climb stairs) become associated with dyspnea and may trigger dyspnea even before physical activity commences. We hypothesized that brain activation relating to such cues would be different between patients with COPD and healthy control subjects, reflecting greater engagement of emotional mechanisms in patients. METHODS: Using functional MRI (FMRI), we investigated brain responses to dyspnea-related word cues in 41 patients with COPD and 40 healthy age-matched control subjects. We combined these findings with scores on self-report questionnaires, thus linking the FMRI task with clinically relevant measures. This approach was adapted from studies in pain that enabled identification of brain networks responsible for pain processing despite absence of a physical challenge. RESULTS: Patients with COPD demonstrated activation in the medial prefrontal cortex and anterior cingulate cortex, which correlated with the visual analog scale (VAS) response to word cues. This activity independently correlated with patient responses on questionnaires of depression, fatigue, and dyspnea vigilance. Activation in the anterior insula, lateral prefrontal cortex, and precuneus correlated with the VAS dyspnea scale but not with the questionnaires. CONCLUSIONS: The findings suggest that engagement of the emotional circuitry of the brain is important for interpretation of dyspnea-related cues in COPD and is influenced by depression, fatigue, and vigilance. A heightened response to salient cues is associated with increased symptom perception in chronic pain and asthma, and the findings suggest that such mechanisms may be relevant in COPD. PMID:26134891

  20. Does nebulized fentanyl relieve dyspnea during exercise in healthy man?

    PubMed Central

    Kotrach, Houssam G.; Bourbeau, Jean

    2015-01-01

    Few therapies exist for the relief of dyspnea in restrictive lung disorders. Accumulating evidence suggests that nebulized opioids selective for the mu-receptor subtype may relieve dyspnea by modulating intrapulmonary opioid receptor activity. Our respective primary and secondary objectives were to test the hypothesis that nebulized fentanyl (a mu-opioid receptor agonist) relieves dyspnea during exercise in the presence of abnormal restrictive ventilatory constraints and to identify the physiological mechanisms of this improvement. In a randomized, double-blind, placebo-controlled crossover study, we examined the effect of 250 μg nebulized fentanyl, chest wall strapping (CWS), and their interaction on detailed physiological and perceptual responses to constant work rate cycle exercise (85% of maximum incremental work rate) in 14 healthy, fit young men. By design, CWS decreased vital capacity by ∼20% and mimicked the negative consequences of a mild restrictive lung disorder on exercise endurance time and on dyspnea, breathing pattern, dynamic operating lung volumes, and diaphragmatic electromyographic and respiratory muscle function during exercise. Compared with placebo under both unrestricted control and CWS conditions, nebulized fentanyl had no effect on exercise endurance time, integrated physiological response to exercise, sensory intensity, unpleasantness ratings of exertional dyspnea. Our results do not support a role for intrapulmonary opioids in the neuromodulation of exertional dyspnea in health nor do they provide a physiological rationale for the use of nebulized fentanyl in the management of dyspnea due to mild restrictive lung disorders, specifically those arising from abnormalities of the chest wall and not affiliated with airway inflammation. PMID:26031762

  1. Cardiopulmonary laboratory biomarkers in the evaluation of acute dyspnea

    PubMed Central

    Stokes, Natalie R; Dietz, Brett W; Liang, Jackson J

    2016-01-01

    Dyspnea is a common chief complaint in the emergency department, with over 4 million visits annually in the US. Establishing the correct diagnosis can be challenging, because the subjective sensation of dyspnea can result from a wide array of underlying pathology, including pulmonary, cardiac, neurologic, psychiatric, toxic, and metabolic disorders. Further, the presence of dyspnea is linked with increased mortality in a variety of conditions, and misdiagnosis of the cause of dyspnea leads to poor patient-level outcomes. In combination with the history and physical, efficient, and focused use of laboratory studies, the various cardiopulmonary biomarkers can be useful in establishing the correct diagnosis and guiding treatment decisions in a timely manner. Use and interpretation of such tests must be guided by the clinical context, as well as an understanding of the current evidence supporting their use. This review discusses current standards and research regarding the use of established and emerging cardiopulmonary laboratory markers in the evaluation of acute dyspnea, focusing on recent evidence assessing the diagnostic and prognostic utility of various tests. These markers include brain natriuretic peptide (BNP) and N-terminal prohormone (NT-proBNP), mid-regional peptides proatrial NP and proadrenomedullin, cardiac troponins, D-dimer, soluble ST2, and galectin 3, and included is a discussion on the use of arterial and venous blood gases. PMID:27307771

  2. Experimental Contact Lens to Prevent Glaucoma-Induced Blindness

    MedlinePlus

    ... Articles | Inside Life Science Home Page An Experimental Contact Lens to Prevent Glaucoma-Induced Blindness By Sharon Reynolds Posted January 23, 2014 An experimental contact lens design releases a glaucoma medicine at a ...

  3. Progressive dyspnea--comprehensive evaluation of a common symptom.

    PubMed

    Postolache, Paraschiva; Nemeş, Roxana-Maria; Cojocaru, Doina-Clementina

    2014-01-01

    Dyspnea is one of the most common symptoms in the clinical setting, the main causes being represented by respiratory and cardiovascular disorders but sometimes it is difficult to identify and document the underlying mechanism of breathlessness. We present the case of a 75-years-old male patient, former smoker, with progressive worsening dyspnea. He performed a complex imagistic, respiratory, and functional assessment, the results showing severe emphysema with mild obstructive syndrome, in contrast with severe impairment of diffusing capacity of the lung for carbon monoxide (DLCO) due to inhomogeneous distribution of ventilation/perfusion ratio. This case brings to front a certain type of chronic obstructive pulmonary disease (COPD), with suggestive clinical exam but with minimal impairment of spirometry results in the presence of debilitating dyspnea. In order to perform an accurate diagnosis, alternative functional diagnostic measurements, like estimation of DLCO, should be used. PMID:25341279

  4. Experimental evaluation of earthquake induced relay chattering

    SciTech Connect

    Bandyopadhyay, K.; Hofmayer, C.; Shteyngart, S.

    1990-01-01

    An experimental evaluation of relay performance under vibratory environments is discussed in this paper. Single frequency excitation was used for most tests. Limited tests were performed with random multifrequency inputs. The capacity of each relay was established based on a two-millisecond chatter criterion. The experimental techniques are described and the effects of parameters in controlling the relay capacity levels are illustrated with test data. A wide variation of the capacity levels was observed due to the influence of parameters related to the design of the relay and nature of the input motion. 3 refs., 15 figs.

  5. Imaging-based assessment of dyspnea in cigarette smokers

    NASA Astrophysics Data System (ADS)

    Galvin, Jeffrey R.; Chang, Paul J.; Schwartz, David A.; Hunninghake, Gary W.; Helmers, Richard; Mori, Masaki

    1994-05-01

    Patients with pulmonary fibrosis frequently smoke cigarettes. The cause of dyspnea in these patients is often complex because of the coexistence of multiple disease processes. We investigated 10 cigarette smokers with pulmonary fibrosis who were referred for evaluation of new onset or worsening dyspnea. Chest radiographs and pulmonary function tests were obtained in addition to high-resolution computed tomography (HRCT). In those patients with HRCT evidence of both diseases, spirometry and lung volumes were most often normal. Although plain films provided a reasonable assessment of fibrosis, they underestimated the severity of emphysema. Quantitation of both emphysema and fibrosis by HRCT was reproducible and correlated with key pulmonary function tests. Our findings indicate that the HRCT scan is a useful diagnostic test in patients with pulmonary fibrosis who are also cigarette smokers.

  6. [Acute dyspnea in the emergency room: from pathophysiology to ultrasonography].

    PubMed

    Rosset-Zufferey, Sarah; Ramlawi, Majd

    2015-08-12

    Acute dyspnea is one of the leading clinical symptoms encountered in the emergency room. Its differential diagnosis is wide, ranging from noisy panic attacks to threatening acute heart failure. History taking and physical examination, even when exhaustive are of limited diagnostic value. Patient reported descriptions are fairly correlated to pathophysiology. Vital signs such as the respiratory rate and pulse oximetry carry prognostic significance. Ancillary tests like the chest x-ray lack sensitivity and specificity. The most astonishing adjunct to testing is the chest ultrasound. Its integration into the emergency physician's armamentarium considerably changed clinical management. Fast and accurate, ultrasonography has become the modern era stethoscope. This review discusses acute dyspnea through the main elements useful to diagnosis. PMID:26449099

  7. Intimal pulmonary artery sarcoma presenting as dyspnea: case report

    PubMed Central

    Hsing, Jeff M; Thakkar, Snehal G; Borden, Ernest C; Budd, George T

    2007-01-01

    Background We report a case of pulmonary sarcoma which is a rare cause of the common symptom of dyspnea. Case presentation A fifty-one year old previously healthy male presented to the emergency room with complaints of dyspnea on exertion. A cardiac workup including an exercise stress test was negative but an echocardiography showed pulmonary stenosis. Cardiac MRI showed a large mass extending from the pulmonic valve to both the right and left pulmonary arteries suggestive of sarcoma. A complete resection and repair of the pulmonary artery was done and adjuvant chemotherapy with doxorubicin and ifosfamide was recommended. The patient is currently disease free after eighteen months. Conclusion Pulmonary artery sarcomas are a difficult diagnosis. The diagnosis may remain elusive for some time until the proper imaging techniques are utilized to make a diagnosis. Earlier and accurate diagnosis may lead to earlier interventions and improve survival. PMID:17603895

  8. Modified Medical Research Council scale vs Baseline Dyspnea Index to evaluate dyspnea in chronic obstructive pulmonary disease

    PubMed Central

    Perez, Thierry; Burgel, Pierre Régis; Paillasseur, Jean-Louis; Caillaud, Denis; Deslée, Gaetan; Chanez, Pascal; Roche, Nicolas

    2015-01-01

    Background Assessment of dyspnea in COPD patients relies in clinical practice on the modified Medical Research Council (mMRC) scale, whereas the Baseline Dyspnea Index (BDI) is mainly used in clinical trials. Little is known on the correspondence between the two methods. Methods Cross-sectional analysis was carried out on data from the French COPD cohort Initiatives BPCO. Dyspnea was assessed by the mMRC scale and the BDI. Spirometry, plethysmography, Hospital Anxiety-Depression Scale, St George’s Respiratory Questionnaire, exacerbation rates, and physician-diagnosed comorbidities were obtained. Correlations between mMRC and BDI scores were assessed using Spearman’s correlation coefficient. An ordinal response model was used to examine the contribution of clinical data and lung function parameters to mMRC and BDI scores. Results Data are given as median (interquartile ranges, [IQR]). Two-hundred thirty-nine COPD subjects were analyzed (men 78%, age 65.0 years [57.0; 73.0], forced expiratory volume in 1 second [FEV1] 48% predicted [34; 67]). The mMRC grade and BDI score were, respectively, 1 [1–3] and 6 [4–8]. Both BDI and mMRC scores were significantly correlated at the group level (rho =−0.67; P<0.0001), but analysis of individual data revealed a large scatter of BDI scores for any given mMRC grade. In multivariate analysis, both mMRC grade and BDI score were independently associated with lower FEV1% pred, higher exacerbation rate, obesity, depression, heart failure, and hyperinflation, as assessed by the inspiratory capacity/total lung capacity ratio. The mMRC dyspnea grade was also associated with the thromboembolic history and low body mass index. Conclusion Dyspnea is a complex symptom with multiple determinants in COPD patients. Although related to similar factors (including hyperinflation, depression, and heart failure), BDI and mMRC scores likely explore differently the dyspnea intensity in COPD patients and are clearly not interchangeable. PMID

  9. Physical inactivity in COPD and increased patient perception of dyspnea

    PubMed Central

    Katajisto, Milla; Kupiainen, Henna; Rantanen, Piritta; Lindqvist, Ari; Kilpeläinen, Maritta; Tikkanen, Heikki; Laitinen, Tarja

    2012-01-01

    Objective: To study patients’ levels of exercise activity and the clinical characteristics that relate to physical activity and inactivity among patients with chronic obstructive pulmonary disease (COPD). Methods: A postal questionnaire was administered to 719 patients with COPD in 2010; patients were recruited from the Helsinki and Turku University Central Hospitals in Finland and have been followed since 2005. The questionnaire asked participants about their exercise routines and other daily activities, potential restrictions to exercise, health-related quality of life, and subjective sensations of dyspnea upon exertion. Results: A total of 50% of the participants reported exercising > 2 times a week throughout the year. The proportion of the exercise inactive patients increased in parallel with disease progression, but the participants exhibited great variation in the degree of activity as well as in sport choices. Year-round activity was better maintained among patients who exercised both indoors and outdoors. Training activity was significantly correlated with patients’ reported subjective dyspnea (r = 0.32, P < 0.001), health-related quality of life (r = 0.25, P < 0.001), mobility score (r = 0.37, P < 0.001), and bronchial obstruction (r = 0.18, P < 0.001). Active patients did not differ from inactive patients in terms of sex, age, smoking status, somatic comorbidities, or body mass index. Irrespective of the level of severity of patients’ COPD, the most significant barrier to exercising was the subjective sensation of dyspnea. Conclusion: When a patient with COPD suffers from dyspnea and does not have regular exercise routines, the patient will most likely benefit from an exercise program tailored to his or her physical capabilities. PMID:23152679

  10. Neural correlates of experimentally induced flow experiences.

    PubMed

    Ulrich, Martin; Keller, Johannes; Hoenig, Klaus; Waller, Christiane; Grön, Georg

    2014-02-01

    Flow refers to a positive, activity-associated, subjective experience under conditions of a perceived fit between skills and task demands. Using functional magnetic resonance perfusion imaging, we investigated the neural correlates of flow in a sample of 27 human subjects. Experimentally, in the flow condition participants worked on mental arithmetic tasks at challenging task difficulty which was automatically and continuously adjusted to individuals' skill level. Experimental settings of "boredom" and "overload" served as comparison conditions. The experience of flow was associated with relative increases in neural activity in the left anterior inferior frontal gyrus (IFG) and the left putamen. Relative decreases in neural activity were observed in the medial prefrontal cortex (MPFC) and the amygdala (AMY). Subjective ratings of the flow experience were significantly associated with changes in neural activity in the IFG, AMY, and, with trend towards significance, in the MPFC. We conclude that neural activity changes in these brain regions reflect psychological processes that map on the characteristic features of flow: coding of increased outcome probability (putamen), deeper sense of cognitive control (IFG), decreased self-referential processing (MPFC), and decreased negative arousal (AMY). PMID:23959200

  11. Experimental and analytical investigation of flow through rocket pump inducer

    NASA Technical Reports Server (NTRS)

    Lakshminarayana, B.

    1974-01-01

    The characteristics of a rocket pump inducer are discussed. The effect of the pumping requirements on the blade configuration is analyzed. The effects of viscosity on blade design were determined by tests of a four bladed inducer operated in air at a flow coefficient of 0.065. The fluid properties were measured at the exit of the inducer using conventional and hot wire probes. The experimental results and the method of predicting the outlet tangential velocity and head rise are discussed.

  12. Mast cell chymase in experimentally induced psoriasis.

    PubMed

    Suttle, Mireille-Maria; Harvima, Ilkka T

    2016-06-01

    Mast cell chymase can have a pro-inflammatory or an immunosuppressive function in psoriasis, but the outcome may depend on the level of chymase activity. Therefore, mast cells showing chymase activity (Chyact ) and immunoreactivity (Chyprot ) were studied during the Köbner reaction (0 days, 2 h, 1 day, 3 days and 7 days) of psoriasis induced by the tape-stripping technique. Also, the effect of recombinant human chymase (rh-chymase) or human LAD2 mast cells (LAD2) on the (3) H-thymidine uptake of psoriatic peripheral blood mononuclear cells (PBMC) or total T cells was studied. The Chyact /Chyprot ratio tended to be higher in all time-point biopsies in the Köbner-negative (n = 10) than -positive (n = 8) group (P = 0.073), although chymase activity decreased significantly at 2 h to 1 day only in the Köbner-negative group. rh-chymase (0.05-0.5 μg/mL) stimulated to a varying extent PBMC in eight out of nine cultures, but in all cultures 5 μg/mL rh-chymase turned the stimulation towards inhibition. The effect of rh-chymase on T cells varied from stimulation to inhibition, but in 11 of 15 cultures rh-chymase, at least at 5 μg/mL, produced a change to inhibition. In co-cultures, LAD2 inhibited PBMC in the absence of soybean trypsin inhibitor (SBTI). In the presence of SBTI, LAD2 stimulated PBMC in the majority of seven cultures. In summary, the psoriatic immunopathogenesis may be promoted at low, but controlled at high, activity status of chymase. PMID:26703925

  13. Prevalence and Predictive Value of Dyspnea Ratings in Hospitalized Patients: Pilot Studies

    PubMed Central

    Stevens, Jennifer P.

    2016-01-01

    Background Dyspnea (breathing discomfort) can be as powerfully aversive as pain, yet is not routinely assessed and documented in the clinical environment. Routine identification and documentation of dyspnea is the first step to improved symptom management and it may also identify patients at risk of negative clinical outcomes. Objective To estimate the prevalence of dyspnea and of dyspnea-associated risk among hospitalized patients. Design Two pilot prospective cohort studies. Setting Single academic medical center. Patients Consecutive patients admitted to four inpatient units: cardiology, hematology/oncology, medicine, and bariatric surgery. Measurements In Study 1, nurses documented current and recent patient-reported dyspnea at the time of the Initial Patient Assessment in 581 inpatients. In Study 2, nurses documented current dyspnea at least once every nursing shift in 367 patients. We describe the prevalence of burdensome dyspnea, and compare it to pain. We also compared dyspnea ratings with a composite of adverse outcomes: 1) receipt of care from the hospital’s rapid response system, 2) transfer to the intensive care unit, or 3) death in hospital. We defined burdensome dyspnea as a rating of 4 or more on a 10-point scale. Results Prevalence of burdensome current dyspnea upon admission (Study 1) was 13% (77 of 581, 95% CI 11%-16%). Prevalence of burdensome dyspnea at some time during the hospitalization (Study 2) was 16% (57 of 367, 95% CI 12%-20%). Dyspnea was associated with higher odds of a negative outcome. Conclusions In two pilot studies, we identified a significant symptom burden of dyspnea in hospitalized patients. Patients reporting dyspnea may benefit from a more careful focus on symptom management and may represent a population at greater risk for negative outcomes. PMID:27070144

  14. A Giant Ovarian Tumor Causing Anasarca and Dyspnea Successfully Managed after Preoperative Drainage.

    PubMed

    Yamaguchi, Munekage; Tashiro, Hironori; Takaishi, Kiyomi; Honda, Ritsuo; Katabuchi, Hidetaka

    2015-01-01

    Serious complications are likely to accompany the treatment of giant ovarian tumors, and resection with or without preoperative drainage has been previously reported. Here, we report the case of a 27-year-old Japanese woman with a significant weight gain of 50 kg, who was referred to the Kumamoto University Hospital because of gait impairment and dyspnea. Imaging tests revealed an ovarian tumor, 37 cm in diameter, with two solid components. The patient's condition improved after the removal of 31.5 l tumor fluid by using a suprapubic urinary catheter for 3 days. The tumor was subsequently resected without complications, and was diagnosed as a left mucinous ovarian tumor with malignant components, weighing 37 kg (81.5 lb). The patient was discharged after her anasarca improved, and her body weight decreased from 100 to 50 kg with accompanying considerable urination within two weeks. She was in good condition with no evidence of recurrence at 15 months after surgery. Tumor resection after preoperative drainage was effective in the management of a patient with dyspnea induced by a giant ovarian tumor. We suggest the use of a suprapubic urinary catheter for preoperative drainage because of its ease of use in preventing fluid leakage from the possibly malignant tumor. PMID:25661539

  15. Explaining Unexplained Dyspnea The Ever “Holesome” Heart

    PubMed Central

    Dudzinski, David M.; Bhatt, Deepak L.; Maron, Bradley A.; Aragam, Jayashri R.

    2014-01-01

    A 63-year-old man was evaluated in consultation for unexplained dyspnea. At the time of the initial clinical encounter at our institution, the patient endorsed a 10-year history of progressive exertional dyspnea, which had become debilitating over the preceding 3 months and was characterized by shortness of breath accompanying subtle physical activities such as tying shoelaces. The patient underwent multiple hospital admissions reportedly for the treatment of congestive heart failure ascribed to impaired left ventricular (LV) diastolic function. Review of systems identified postural dizziness and history of near syncope, possible nocturnal dyspnea, and peripheral neuropathy, but not cardiac angina, orthopnea, nocturia, edema, cough, palpitations, syncope, claudication, or other cardiopulmonary symptoms. He related that he was first noted to have a cardiac murmur detected 4 decades previously during a military service physical examination but that the murmur was not characterized further and that he served in the Vietnam conflict without functional limitation. The patient’s relevant medical history included rate-controlled atrial fibrillation, 90 pack-year tobacco use (3 packs daily between 21 and 51 years of age), dyslipidemia, systemic hypertension, type 2 diabetes mellitus, moderate chronic obstructive pulmonary disease, obstructive sleep apnea not currently treated, and gastrointestinal bleed caused by colon cancer treated with hemicolectomy 11 years earlier. There was no illicit drug use, but a remote history of heavy alcohol consumption was reported. Family history was unremarkable except that his father died at 55 years of age of myocardial infarction. Medications included aspirin 81 mg daily, warfarin 2 mg daily, losartan 50 mg daily, metoprolol tartrate 25 mg twice daily, simvastatin 10 mg daily, fenofibrate 48 mg daily, albuterol inhaler 90-μg puffs as needed, and gabapentin 300 mg 3 times daily. PMID:25446059

  16. Qualitative dimensions of exertional dyspnea in adults with cystic fibrosis.

    PubMed

    Quon, Bradley S; Wilkie, Sabrina S; Ramsook, Andrew H; Schaeffer, Michele R; Puyat, Joseph H; Wilcox, Pearce G; Guenette, Jordan A

    2016-08-01

    No studies of cystic fibrosis (CF) have systematically characterized the evolution of the qualitative dimensions of exertional dyspnea. Adults with CF (n = 25) and control individuals matched for sex, age, and body mass index (n = 25) underwent cardiopulmonary cycle exercise testing with a detailed evaluation of ventilatory and dyspnea responses. The qualitative dimensions of dyspnea were examined during each exercise stage by having subjects select phrases that best described their breathing (i.e., "work/effort," "unsatisfied inspiration," and "unsatisfied expiration"). Subjects also selected phrases that described the quality of their breathing at peak exercise using an established 15-item questionnaire, which was then clustered into different categories. Subjects with CF had greater ventilatory requirements, higher end-inspiratory and end-expiratory lung volumes (% total lung capacity), and an earlier inflection/plateau in tidal volume during exercise compared with control subjects. Increased work/effort was the dominant qualitative descriptor in both groups throughout exercise. Unsatisfied inspiration was selected by 48% of subjects with CF and 40% of controls at some point during exercise. The onset of unsatisfied inspiration in these subjects occurred at a significantly lower relative exercise intensity in subjects with CF vs. controls (72 ± 21 vs. 94 ± 11% Wmax, P < 0.01). Chest tightness was the only qualitative descriptor cluster that was selected more frequently by subjects with CF vs. controls (36 vs. 0%, respectively, P < 0.05) at peak exercise. Therapeutic interventions that reduce ventilatory requirements and improve lung volumes may delay the onset of distressing sensations such as unsatisfied inspiration and chest tightness in adults with CF. PMID:27311438

  17. Severe dyspnea as atypical presenting symptom of Madelung's disease

    PubMed Central

    Milisavljevic, D; Zivic, M; Radovanović, Z; Stankovic, P

    2010-01-01

    Madelung's disease (benign symmetrical lipomatosis) is a rare disease of unknown etiology manifesting as symmetric abnormal deposits of adipose tissue in the head, neck and upper trunk. We report a case of a 58-year-old man with a long lasting Madelungs disease in whom progressive fatty tissue accumulation caused a severe inspiratory dyspnea as atypical presenting symptom. The etiopathogenetic, clinico-diagnostic and therapeutic aspects of this rare disease are discussed. Due to its progressive but not so easily predictable enlarging behavior Madelung's disease has not only aesthetic but also functional and sometimes life threatening consequences which need to be treated. PMID:20596272

  18. Experimental background due to particle induced gas desorption in RHIC

    SciTech Connect

    Zhang,S.Y.; Trbojevic, D.

    2008-08-10

    Beam-gas collision created experimental background, i.e., singles, has affected heavy ion and polarized proton operations in Relativistic Heavy Ion Collider at Brookhaven National Laboratory. The gas molecules in interaction region are mainly caused by the electron induced gas desorption. and the electrons are produced from the beam induced electron multipacting, or called electron cloud. The background has a dependence on the usual electron cloud related parameters, such as the bunch intensity, bunch spacing, and the solenoid field. With the RHIC upgrade plan, the experimental background may become a luminosity limiting factor. Mitigations are discussed.

  19. Experimentally induced otitis and audiogenic seizure in the mouse.

    PubMed

    Niaussat, M M

    1977-04-15

    Audiogenic seizures can be induced in genetically non-susceptible 17-day-old mice (Rb/3 strain) with various results. Priming only induces 9% of seizures, auditory insulation 3,8%, while experimental otitis leads to 79%. The hypothesis concerning disuse supersensitivity subsequent to acoustic deprivation was not confirmed by the experiment. However, modification of acoustic transmission at middle ear level induced by otitis or ear physical damage during the maturation period, exposes the upper nervous centers to intense stimulation to which the reaction is a recruiting response. PMID:862735

  20. Parapharyngeal space lipomatosis with secondary dyspnea, disphagia and disphonia

    PubMed Central

    Garcia-Ortega, Dorian Yarih; Gomez-Pedraza, Antonio; Luna-Ortiz, Kuauhyama

    2015-01-01

    Introduction Parapharyngeal space tumors are a small percentage of all head and neck neoplasms. Due to their anatomic location, they represent a therapeutic challenge. To our knowledge, 11 cases of parapharyngeal lipomatous tumors have been reported in the literature. Case A 48 year old male with chief complaints of dyspnea, dysphagia and dysphonia was found to have a parapharyngeal space tumor. He was scheduled to undergo lumpectomy and neck exploration. Discussion Benign tumors represented 70% of all cases. Open neck surgery is considered the gold-standard of treatment. Conclusion It is important to bear in mind the lipomas of the parapharyngeal space to establish an accurate diagnosis and implement timely, appropriate treatment in order to avoid future complications and reduce morbidity and mortality. PMID:26318127

  1. PHARMACOLOGIC TREATMENT OF HYPERALGESIA EXPERIMENTALLY INDUCED BY NUCLEUS PULPOSUS

    PubMed Central

    de Souza Grava, André Luiz; Ferrari, Luiz Fernando; Parada, Carlos Amílcar; Defino, Helton Luiz Aparecido

    2015-01-01

    Objective: To evaluate the effect of anti-inflammatory drugs (dexamethasone, indomethacin, atenolol and indomethacin plus atenolol) and analgesic drugs (morphine) on hyperalgesia experimentally induced by the nucleus pulposus (NP) in contact with the L5 dorsal root ganglion (DRG). Methods: Thirty male Wistar rats of weights ranging from 220 to 250 g were used in the study. Hyperalgesia was induced by means of a fragment of NP removed from the sacrococcygeal region that was placed in contact with the L5 dorsal root ganglion. The 30 animals were divided into experimental groups according to the drug used. The drugs were administered for two weeks after the surgical procedure to induce hyperalgesia. Mechanical and thermal hyperalgesia was evaluated using the paw pressure test, von Frey electronic test and Hargreaves test, over a seven-week period. Results: The greatest reduction of hyperalgesia was observed in the group of animals treated with morphine, followed by dexamethasone, indomethacin and atenolol. Reductions in hyperalgesia were observed after drug administration ceased, except for the group of animals treated with morphine, in which there was an increase in hyperalgesia after discontinuation of the treatment. Conclusion: Hyperalgesia induced by NP contact with the DRG can be reduced through administration of anti-inflammatory and analgesic drugs, but a greater reduction was observed with the administration of dexamethasone. PMID:27026966

  2. Unrecognized suffering in the ICU: Addressing dyspnea in mechanically ventilated patients

    PubMed Central

    Schmidt, Matthieu; Banzett, Robert B.; Raux, Mathieu; Morélot-Panzini, Capucine; Dangers, Laurence; Similowski, Thomas; Demoule, Alexandre

    2014-01-01

    Background Intensive care unit (ICU) patients are exposed to many sources of discomfort. Although growing attention has been given to the detection and treatment of pain, very little has been given to the detection and treatment of dyspnea (defined as ‘breathing discomfort’). Discussion In this article, we review the published information on prevalence, mechanisms and potential negative impacts of dyspnea in mechanically ventilated patients. In addition, we review the most appropriate tools to detect and quantify dyspnea in ICU patients. Conclusions Growing evidence suggests that dyspnea is a frequent issue in mechanically ventilated ICU patients, is highly associated with anxiety and pain, and is improved in many patients by altering ventilator settings. Future studies are needed to better delineate the impact of dyspnea in the ICU, and to define diagnostic, monitoring and therapeutic protocols. PMID:24132382

  3. [Clinical significance of natriuretic peptides in the differential diagnosis of dyspnea].

    PubMed

    Špác, Jiří

    2016-01-01

    Acute dyspnea is one of the most common emergency department symptoms. But early diagnosis and treatment could be e challenging because of multiple potential causes. The gold standard biomarkers in cardiac dyspnea are B-type natriuretic peptide (BNP) and N-terminal pro-B-type (natriuretic peptide NT-pro BNP), which play an important role in the diagnosis, prognosis, and management of acute decompensated heart failure. The purpose of this review is to analyze diagnostic potential of BNP and NT-pro BNP biomarkers use in patients with acute dyspnea. BNP and NT-proBNP are markers of cardiac stress but are not cardiac-specific. They have comparable clinical utility, and both help in excluding acute cardiac dyspnea but they cannot reliably discriminate systolic from diastolic HF.Key word: acute dyspnea - natriuretic peptide - heart failure. PMID:27627091

  4. Elastase-induced pulmonary emphysema: insights from experimental models.

    PubMed

    Antunes, Mariana A; Rocco, Patricia R M

    2011-12-01

    Several distinct stimuli can be used to reproduce histological and functional features of human emphysema, a leading cause of disability and death. Since cigarette smoke is the main cause of emphysema in humans, experimental researches have attempted to reproduce this situation. However, this is an expensive and cumbersome method of emphysema induction, and simpler, more efficacious alternatives have been sought. Among these approaches, elastolytic enzymes have been widely used to reproduce some characteristics of human cigarette smoke-induced disease, such as: augmentation of airspaces, inflammatory cell influx into the lungs, and systemic inflammation. Nevertheless, the use of elastase-induced emphysema models is still controversial, since the disease pathways involved in elastase induction may differ from those occurring in smoke-induced emphysema. This indicates that the choice of an emphysema model may impact the results of new therapies or drugs being tested. The aim of this review is to compare the mechanisms of disease induction in smoke and elastase emphysema models, to describe the differences among various elastase models, and to establish the advantages and disadvantages of elastase-induced emphysema models. More studies are required to shed light on the mechanisms of elastase-induced emphysema. PMID:22159348

  5. Experimentally induced rodent models of type 2 diabetes.

    PubMed

    Islam, Md Shahidul; Wilson, Rachel Dorothy

    2012-01-01

    Diabetes is one of the major global public health problems and is gradually getting worse particularly in developing nations where 95% of patients are suffering from type 2 diabetes (T2D). Animal models in diabetes research are very common where rodents are the best choice of use due to being smaller in size, easy to handle, omnivorous in nature, and non-wild tranquil behavior. Normally rodent models are classified into two major classes namely: (1) genetic or spontaneously induced models and (2) non-genetic or experimentally induced models. Non-genetic models are more popular compared to genetic models due to lower cost, wider availability, easier to induce diabetes, and of course easier to maintain compared to genetic models. A number of non-genetic models have been developed in last three decades for diabetes research including adult alloxan/streptozotocin (STZ) models, partial pancreatectomy model, high-fat (HF) diet-fed models, fructose-fed models, HF diet-fed STZ models, nicotinamide-STZ models, monosodium-glutamate (MSG) induced models, and intrauterine growth retardation (IUGR) models. A T2D model should have the all major pathogenesis of the disease usually found in humans; however, none of the above-mentioned models are without limitations. This chapter comparatively evaluates most of the experimentally induced rodent models of T2D with their limitations, advantages, disadvantages, and criticality of development in order to help diabetes research groups to more appropriately select the animal models to work on their specific research question. PMID:22893406

  6. The effect of experimentally-induced subacromial pain on proprioception.

    PubMed

    Sole, Gisela; Osborne, Hamish; Wassinger, Craig

    2015-02-01

    Shoulder injuries may be associated with proprioceptive deficits, however, it is unknown whether these changes are due to the experience of pain, tissue damage, or a combination of these. The aim of this study was to investigate the effect of experimentally-induced sub-acromial pain on proprioceptive variables. Sub-acromial pain was induced via hypertonic saline injection in 20 healthy participants. Passive joint replication (PJR) and threshold to detection of movement direction (TTDMD) were assessed with a Biodex System 3 Pro isokinetic dynamometer for baseline control, experimental pain and recovery control conditions with a starting position of 60° shoulder abduction. The target angle for PJR was 60° external rotation, starting from 40°. TTDMD was tested from a position of 20° external rotation. Repeated measures ANOVAs were used to determine differences between PJR absolute and variable errors and TTDMD for the control and experimental conditions. Pain was elicited with a median 7 on the Numeric Pain Rating Scale. TTDMD was significantly decreased for the experimental pain condition compared to baseline and recovery conditions (≈30%, P = 0.003). No significant differences were found for absolute (P = 0.152) and variable (P = 0.514) error for PJR. Movement sense was enhanced for the experimental sub-acromial pain condition, which may reflect protective effects of the central nervous system in response to the pain. Where decreased passive proprioception is observed in shoulders with injuries, these may be due to a combination of peripheral tissue injury and neural adaptations that differ from those due to acute pain. PMID:25261091

  7. Weight loss reduces dyspnea on exertion in obese women.

    PubMed

    Bernhardt, Vipa; Babb, Tony G

    2014-12-01

    During submaximal exercise, some otherwise healthy obese women experience breathlessness, or dyspnea on exertion (+DOE), while others have mild or no DOE (-DOE). We investigated whether weight loss could reduce DOE. Twenty nine obese women were grouped based on their Ratings of Perceived Breathlessness (RPB) during constant load 60 W cycling: +DOE (n = 14, RPB ≥ 4, 34 ± 8 years, and 36 ± 3 kg/m(2)) and -DOE ( n= 15, RPB ≤ 2, 32 ± 8 years, and 36 ± 4 kg/m(2)) and then completed a 12-week weight loss program. Both groups lost a moderate amount of weight (+DOE: 6.6 ± 2.4 kg, -DOE: 8.4 ± 3.5 kg, and p < 0.001). RPB decreased significantly in the +DOE group (from 4.7 ± 1.1 to 3.1 ± 1.6) and remained low in the -DOE (from 1.5 ± 0.7 to 1.6 ± 1.1) (interaction p < 0.002). Most physiological variables measured (i.e. body composition, fat distribution, pulmonary function, oxygen cost of breathing, and cardiorespiratory measures) improved with weight loss; however, the decrease in RPB was not correlated with any of these variables (p > 0.05). In conclusion, moderate weight loss was effective in reducing breathlessness on exertion in obese women who experienced DOE at baseline. PMID:25220695

  8. Dyspnea in a nonagenarian: The usual suspects, an unexpected culprit.

    PubMed

    Madeira, Sérgio; Raposo, Luís; David, Raquel; Marques, Alexandre; Andrade Gomes, José; Cardim, Nuno; Anjos, Rui

    2015-09-01

    Platypnea-orthodeoxia syndrome (POS) is an uncommon syndrome characterized by dyspnea and hypoxemia triggered by orthostatism and relieved by recumbency. It is often associated with an interatrial shunt through a patent foramen ovale (PFO). We report the case of a 92-year-old woman initially admitted in the setting of a traumatic femoral neck fracture (successfully treated with hip replacement surgery) in whom a reversible decline in transcutaneous oxygen saturation from 98% (in the supine position) to 84% (in the upright position) was noted early post-operatively. Thoracic multislice computed tomography excluded pulmonary embolism and severe parenchymal lung disease. The diagnosis of POS was confirmed by tilt-table contrast transesophageal echocardiography, which demonstrated a dynamic and position-dependent right-to-left shunt (torrential when semi-upright and minimal in the supine position) through a PFO. The patient underwent percutaneous closure of the PFO with an Amplatzer device, which led to prompt symptom relief and full functional recovery. PMID:26320092

  9. Immediate effects of chocolate on experimentally induced mood states.

    PubMed

    Macht, Michael; Mueller, Jochen

    2007-11-01

    In this work two hypotheses were tested: (1) that eating a piece of chocolate immediately affects negative, but not positive or neutral mood, and (2) that this effect is due to palatability. Experiment 1 (48 normal-weight and healthy women and men) examined the effects of eating a piece of chocolate and drinking water on negative, positive and neutral mood states induced by film clips. Eating chocolate reduced negative mood compared to drinking water, whereas no or only marginal effects were found on neutral and positive moods. Experiment 2 (113 normal-weight and healthy women and men) compared effects of eating palatable and unpalatable chocolate on negative mood, and examined the duration of chocolate-induced mood change. Negative mood was improved after eating palatable chocolate as compared to unpalatable chocolate or nothing. This effect was short lived, i.e., it disappeared after 3 min. In both experiments, chocolate-induced mood improvement was associated with emotional eating. The present studies demonstrate that eating a small amount of sweet food improves an experimentally induced negative mood state immediately and selectively and that this effect of chocolate is due to palatability. It is hypothesized that immediate mood effects of palatable food contribute to the habit of eating to cope with stress. PMID:17597253

  10. Ichnocarpus frutescens Ameliorates Experimentally Induced Convulsion in Rats

    PubMed Central

    Singh, Narendra Kumar; Laloo, Damiki; Garabadu, Debapriya; Singh, Tryambak Deo; Singh, Virendra Pratap

    2014-01-01

    The present study was carried out to evaluate the anticonvulsant activity and probable mechanism of action of the methanol root extract from I. frutescens (MEIF) using different experimental animal models. Anticonvulsant activity of the single dose of MEIF (100, 200, and 400 mg/kg, p.o.) was evaluated in maximal electroshock- (MES-), pentylenetetrazole- (PTZ-), and isoniazid- (INH-) induced convulsions models in rats. The levels of γ-amino butyric acid (GABA), glutamate, GABA-transaminase (GABA-T) activity and oxidative stress markers were measured in pretreated rat's brain homogenate to corroborate the mechanism of observed anticonvulsant activity. MEIF (200–400 mg/kg, p.o.) protected the animals in all the behavioral models used. Pretreatment of MEIF (200–400 mg/kg, p.o.) and diazepam (1.0 mg/kg, i.p.) to the animals in INH-induced convulsion model showed 100% and 80% protection, respectively, as well as significant restoration of GABA and glutamate level in the rat's brain. MEIF and vigabatrin (50 mg/kg, i.p.) reduced the PTZ-induced increase in the activity of GABA-T (46%) in the brain. Further, MEIF reversed the PTZ-induced increase in lipid peroxidase (LPO) and decrease in reduced glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) activities. The findings of this study validate the anticonvulsant activity of I. frutescens. PMID:27379268

  11. An official American Thoracic Society workshop report: assessment and palliative management of dyspnea crisis.

    PubMed

    Mularski, Richard A; Reinke, Lynn F; Carrieri-Kohlman, Virginia; Fischer, Mark D; Campbell, Margaret L; Rocker, Graeme; Schneidman, Ann; Jacobs, Susan S; Arnold, Robert; Benditt, Joshua O; Booth, Sara; Byock, Ira; Chan, Garrett K; Curtis, J Randall; Donesky, Doranne; Hansen-Flaschen, John; Heffner, John; Klein, Russell; Limberg, Trina M; Manning, Harold L; Morrison, R Sean; Ries, Andrew L; Schmidt, Gregory A; Selecky, Paul A; Truog, Robert D; Wang, Angela C C; White, Douglas B

    2013-10-01

    In 2009, the American Thoracic Society (ATS) funded an assembly project, Palliative Management of Dyspnea Crisis, to focus on identification, management, and optimal resource utilization for effective palliation of acute episodes of dyspnea. We conducted a comprehensive search of the medical literature and evaluated available evidence from systematic evidence-based reviews (SEBRs) using a modified AMSTAR approach and then summarized the palliative management knowledge base for participants to use in discourse at a 2009 ATS workshop. We used an informal consensus process to develop a working definition of this novel entity and established an Ad Hoc Committee on Palliative Management of Dyspnea Crisis to further develop an official ATS document on the topic. The Ad Hoc Committee members defined dyspnea crisis as "sustained and severe resting breathing discomfort that occurs in patients with advanced, often life-limiting illness and overwhelms the patient and caregivers' ability to achieve symptom relief." Dyspnea crisis can occur suddenly and is characteristically without a reversible etiology. The workshop participants focused on dyspnea crisis management for patients in whom the goals of care are focused on palliation and for whom endotracheal intubation and mechanical ventilation are not consistent with articulated preferences. However, approaches to dyspnea crisis may also be appropriate for patients electing life-sustaining treatment. The Ad Hoc Committee developed a Workshop Report concerning assessment of dyspnea crisis; ethical and professional considerations; efficient utilization, communication, and care coordination; clinical management of dyspnea crisis; development of patient education and provider aid products; and enhancing implementation with audit and quality improvement. PMID:24161068

  12. Acupuncture for dyspnea in advanced cancer: a randomized, placebo-controlled pilot trial [ISRCTN89462491

    PubMed Central

    Vickers, Andrew J; Feinstein, Marc B; Deng, Gary E; Cassileth, Barrie R

    2005-01-01

    Background Dyspnea, or shortness of breath, is a common symptom in patients with advanced cancer. Pharmacologic management is of proven benefit, but it does not help all patients. Preliminary data suggest that acupuncture can relieve dyspnea in a variety of populations, including cancer patients. We conducted a pilot study (ISRCTN89462491) preparatory to a fully powered randomized, placebo-controlled trial to determine whether acupuncture reduces dyspnea in patients with lung or breast cancer. Methods The study sample was comprised of forty-seven patients with lung or breast cancer presenting with dyspnea. Patients receiving symptomatic treatments were not excluded as long as no changes in management were planned during the trial. Patients were randomized to receive a single session of true or placebo acupuncture in addition to their existing dyspnea treatments. Semi-permanent acupuncture "studs" were then inserted: patients applied pressure to these studs twice a day to provide ongoing stimulation to acupuncture points. The subjective sensation of dyspnea was assessed with a 0 – 10 numerical rating scale immediately before and after acupuncture treatment and daily for a week thereafter. Results All but two of 47 randomized patients provided follow-up data. Dyspnea scores were slightly higher for patients receiving true versus placebo acupuncture, for both the period immediately following acupuncture treatment and for the daily one week follow-up (differences between means of 0.34, 95% C.I. -0.33, 1.02 and 0.56, 95% C.I. -0.39, 1.51). The 95% confidence interval excludes the prespecified minimum clinically significant difference of a 20% greater improvement in dyspnea for patients receiving acupuncture. Conclusion The acupuncture technique used in this trial is unlikely to have effects on dyspnea importantly larger than placebo for patients with advanced cancer. PMID:16109163

  13. [Diagnosing the cause of acute dyspnea in elderly patients: role of biomarkers in emergencies].

    PubMed

    Teixeira, Antonio; Legrain, Sylvie; Ray, Patrick

    2009-10-01

    Acute dyspnea is one of the leading causes of emergency hospitalization of elderly patients. Clinical diagnostic procedures are difficult in this geriatric population. Acute heart failure is the most frequent cause of acute dyspnea in geriatric patients. The use of plasma B natriuretic peptide (BNP) assays in the general population has profoundly improved its medical management. There has also been progress recently for other frequent causes of dyspnea in the elderly, including infection and venous thromboembolic disease. Procalcitonin assays may be useful as a prognostic factor for infectious disease. Nevertheless, the real value of BNP assays in geriatric populations must be clarified by interventional studies. PMID:19297125

  14. Evidence-based review of interventions to improve palliation of pain, dyspnea, depression.

    PubMed

    Naqvi, Fatima; Cervo, Frank; Fields, Suzanne

    2009-08-01

    This review of the guideline developed by the Clinical Efficacy Subcommittee of the American College of Physicians and the accompanying systematic review offers clinicians evidence-based recommendations for palliative care. Seriously ill patients should be assessed for pain, dyspnea, and depression. Clinicians should use therapies of proven effectiveness to manage pain, depression, and dyspnea, including opioids in patients with unrelieved dyspnea and oxygen for short-term relief of hypoxemia. Clinicians should ensure that advance care planning, including completion of advance directives, occurs. PMID:20722311

  15. Experimental analysis of radiation- and streaming-induced microparticle acoustophoresis

    NASA Astrophysics Data System (ADS)

    Rossi, Massimiliano; Marin, Alvaro; Kähler, Christian J.; Augustsson, Per; Laurell, Thomas; Muller, Peter B.; Barnkob, Rune; Bruus, Henrik

    2012-11-01

    We present an experimental analysis of the acoustophoretic motion of microparticles suspended in a liquid-filled acoustofluidic microchannel. This analysis intends to provide an experimental validation and support to very recent numerical and analytical models of radiation- and streaming-induced microparticle acoustophoresis (see Muller et al., Lab Chip 12, in press, 2012). For the experiments, we used a suspension of water and spherical polystyrene particles in a straight microchannel with rectangular cross section, actuated in its 1.94-MHz resonance by means of a piezoelectric transducer. The particles were labeled with a fluorescent dye and their motion was observed using an epifluorescent microscope. For the analysis, the Astigmatism Particle Tracking Velocimetry (APTV) technique was used to measure the three-dimensional trajectories and velocities of the particles with high precision and resolution (Cierpka et al., Meas Sci Technol 22, 2011). The experiments were performed for different particle sizes, ranging from 0.5- μm particles, dominated by the Stokes drag force induced by the acoustic streaming of the flow, to 5- μm particles, dominated by the acoustic radiation force. The results agree well with the analytical and numerical predictions.

  16. Experimental microembolism induces localized neuritic pathology in guinea pig cerebrum

    PubMed Central

    Li, Jian-Ming; Cai, Yan; Liu, Fei; Yang, La; Hu, Xia; Patrylo, Peter R.; Cai, Huaibin; Luo, Xue-Gang; Xiao, Dong; Yan, Xiao-Xin

    2015-01-01

    Microbleeds are a common finding in aged human brains. In Alzheimer's disease (AD), neuritic plaques composed of β-amyloid (Aβ) deposits and dystrophic neurites occur frequently around cerebral vasculature, raising a compelling question as to whether, and if so, how, microvascular abnormality and amyloid/neuritic pathology might be causally related. Here we used a guinea pig model of cerebral microembolism to explore a potential inductive effect of vascular injury on neuritic and amyloid pathogenesis. Brains were examined 7-30 days after experimental microvascular embolization occupying ~0.5% of total cortical area. Compared to sham-operated controls, glial fibrillary acidic protein immunoreactivity was increased in the embolized cerebrum, evidently around intracortical vasculature. Swollen/sprouting neurites exhibiting increased reactivity of nicotinamide adenine dinucleotide phosphate diaphorase, parvalbumin, vesicular glutamate transporter 1 and choline acetyltransferase appeared locally in the embolized brains in proximity to intracortical vasculature. The embolization-induced swollen/sprouting neurites were also robustly immunoreactive for β-amyloid precursor protein and β-secretase-1, the substrate and initiating enzyme for Aβ genesis. These experimental data suggest that microvascular injury can induce multisystem neuritic pathology associated with an enhanced amyloidogenic potential in wild-type mammalian brain. PMID:25871402

  17. Experimental microembolism induces localized neuritic pathology in guinea pig cerebrum.

    PubMed

    Li, Jian-Ming; Cai, Yan; Liu, Fei; Yang, La; Hu, Xia; Patrylo, Peter R; Cai, Huaibin; Luo, Xue-Gang; Xiao, Dong; Yan, Xiao-Xin

    2015-05-10

    Microbleeds are a common finding in aged human brains. In Alzheimer's disease (AD), neuritic plaques composed of β-amyloid (Aβ) deposits and dystrophic neurites occur frequently around cerebral vasculature, raising a compelling question as to whether, and if so, how, microvascular abnormality and amyloid/neuritic pathology might be causally related. Here we used a guinea pig model of cerebral microembolism to explore a potential inductive effect of vascular injury on neuritic and amyloid pathogenesis. Brains were examined 7-30 days after experimental microvascular embolization occupying ~0.5% of total cortical area. Compared to sham-operated controls, glial fibrillary acidic protein immunoreactivity was increased in the embolized cerebrum, evidently around intracortical vasculature. Swollen/sprouting neurites exhibiting increased reactivity of nicotinamide adenine dinucleotide phosphate diaphorase, parvalbumin, vesicular glutamate transporter 1 and choline acetyltransferase appeared locally in the embolized brains in proximity to intracortical vasculature. The embolization-induced swollen/sprouting neurites were also robustly immunoreactive for β-amyloid precursor protein and β-secretase-1, the substrate and initiating enzyme for Aβ genesis. These experimental data suggest that microvascular injury can induce multisystem neuritic pathology associated with an enhanced amyloidogenic potential in wild-type mammalian brain. PMID:25871402

  18. The influence of experimentally induced pain on shoulder muscle activity.

    PubMed

    Diederichsen, Louise Pyndt; Winther, Annika; Dyhre-Poulsen, Poul; Krogsgaard, Michael R; Nørregaard, Jesper

    2009-04-01

    Muscle function is altered in painful shoulder conditions. However, the influence of shoulder pain on muscle coordination of the shoulder has not been fully clarified. The aim of the present study was to examine the effect of experimentally induced shoulder pain on shoulder muscle function. Eleven healthy men (range 22-27 years), with no history of shoulder or cervical problems, were included in the study. Pain was induced by 5% hypertonic saline injections into the supraspinatus muscle or subacromially. Seated in a shoulder machine, subjects performed standardized concentric abduction (0 degrees -105 degrees) at a speed of approximately 120 degrees/s, controlled by a metronome. During abduction, electromyographic (EMG) activity was recorded by intramuscular wire electrodes inserted in two deeply located shoulder muscles and by surface-electrodes over six superficially located shoulder muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper trapezius and the infraspinatus and an increase in activity of lower trapezius and latissimus dorsi muscles. Following subacromial injection a significantly increased muscle activity was seen in the lower trapezius, the serratus anterior and the latissimus dorsi muscles. In conclusion, this study shows that acute pain both subacromially and in the supraspinatus muscle modulates coordination of the shoulder muscles during voluntary movements. During painful conditions, an increased activity was detected in the antagonist (latissimus), which support the idea that localized pain affects muscle activation in a way that protects the painful structure. Further, the changes in muscle activity following subacromial pain induction tend to expand the subacromial space and thereby decrease the load

  19. In vivo Expression of Inducible Nitric Oxide Synthase in Experimentally Induced Neurologic Diseases

    NASA Astrophysics Data System (ADS)

    Koprowski, Hilary; Zheng, Yong Mu; Heber-Katz, Ellen; Fraser, Nigel; Rorke, Lucy; Fu, Zhen Fang; Hanlon, Cathleen; Dietzschold, Bernhard

    1993-04-01

    The purpose of this study was to investigate the induction of inducible nitric oxide synthase (iNOS) mRNA in the brain tissue of rats and mice under the following experimental conditions: in rats infected with borna disease virus and rabies virus, in mice infected with herpes simplex virus, and in rats after the induction of experimental allergic encephalitis. The results showed that iNOS mRNA, normally nondetectable in the brain, was present in animals after viral infection or after induction of experimental allergic encephalitis. The induction of iNOS mRNA coincided with the severity of clinical signs and in some cases with the presence of inflammatory cells in the brain. The results indicate that nitric oxide produced by cells induced by iNOS may be the toxic factor accounting for cell damage and this may open the door to approaches to the study of the pathogenesis of neurological diseases.

  20. Experimental diabetes in neonatal mice induces early peripheral sensorimotor neuropathy.

    PubMed

    Ariza, L; Pagès, G; García-Lareu, B; Cobianchi, S; Otaegui, P J; Ruberte, J; Chillón, M; Navarro, X; Bosch, A

    2014-08-22

    Animal models of diabetes do not reach the severity of human diabetic neuropathy but relatively mild neurophysiological deficits and minor morphometric changes. The lack of degenerative neuropathy in diabetic rodent models seems to be a consequence of the shorter length of the axons or the shorter animal life span. Diabetes-induced demyelination needs many weeks or even months before it can be evident by morphometrical analysis. In mice myelination of the peripheral nervous system starts at the prenatal period and it is complete several days after birth. Here we induced experimental diabetes to neonatal mice and we evaluated its effect on the peripheral nerve 4 and 8 weeks after diabetes induction. Neurophysiological values showed a decline in sensory nerve conduction velocity at both time-points. Morphometrical analysis of the tibial nerve demonstrated a decrease in the number of myelinated fibers, fiber size and myelin thickness at both time-points studied. Moreover, aldose reductase and poly(ADP-ribose) polymerase activities were increased even if the amount of the enzyme was not affected. Thus, type 1 diabetes in newborn mice induces early peripheral neuropathy and may be a good model to assay pharmacological or gene therapy strategies to treat diabetic neuropathy. PMID:24846610

  1. Practical Dyspnea Assessment: Relationship Between the 0–10 Numerical Rating Scale and the Four-Level Categorical Verbal Descriptor Scale of Dyspnea Intensity

    PubMed Central

    Wysham, Nicholas G.; Miriovsky, Benjamin J.; Currow, David C.; Herndon, James E.; Samsa, Gregory P.; Wilcock, Andrew; Abernethy, Amy P.

    2016-01-01

    Context Measurement of dyspnea is important for clinical care and research. Objectives To characterize the relationship between the 0–10 Numerical Rating Scale (NRS) and four-level categorical Verbal Descriptor Scale (VDS) for dyspnea assessment. Methods This was a substudy of a double-blind randomized controlled trial comparing palliative oxygen to room air for relief of refractory breathlessness in patients with life-limiting illness. Dyspnea was assessed with both a 0–10 NRS and a four-level categorical VDS over the one-week trial. NRS and VDS responses were analyzed in cross section and longitudinally. Relationships between NRS and VDS responses were portrayed using descriptive statistics and visual representations. Results Two hundred twenty-six participants contributed responses. At baseline, mild and moderate levels of breathlessness were reported by 41.9% and 44.6% of participants, respectively. NRS scores demonstrated increasing mean and median levels for increasing VDS intensity, from a mean (SD) of 0.6 (±1.04) for VDS none category to 8.2 (1.4) for VDS severe category. The Spearman correlation coefficient was strong at 0.78 (P < 0.0001). Based on the distribution of NRS scores within VDS categories, we calculated test characteristics of two different cutpoint models. Both models yielded 75% correct translations from NRS to VDS; however, Model A was more sensitive for moderate or greater dyspnea, with fewer misses downcoded. Conclusion There is strong correlation between VDS and NRS measures for dyspnea. Proposed practical cutpoints for the relationship between the dyspnea VDS and NRS are 0 for none, 1–4 for mild, 5–8 for moderate, and 9–10 for severe. PMID:26004401

  2. Mechanisms of blast induced brain injuries, experimental studies in rats.

    PubMed

    Risling, M; Plantman, S; Angeria, M; Rostami, E; Bellander, B-M; Kirkegaard, M; Arborelius, U; Davidsson, J

    2011-01-01

    Traumatic brain injuries (TBI) potentially induced by blast waves from detonations result in significant diagnostic problems. It may be assumed that several mechanisms contribute to the injury. This study is an attempt to characterize the presumed components of the blast induced TBI. Our experimental models include a blast tube in which an anesthetized rat can be exposed to controlled detonations of explosives that result in a pressure wave with a magnitude between 130 and 260 kPa. In this model, the animal is fixed with a metal net to avoid head acceleration forces. The second model is a controlled penetration of a 2mm thick needle. In the third model the animal is subjected to a high-speed sagittal rotation angular acceleration. Immunohistochemical labeling for amyloid precursor protein revealed signs of diffuse axonal injury (DAI) in the penetration and rotation models. Signs of punctuate inflammation were observed after focal and rotation injury. Exposure in the blast tube did not induce DAI or detectable cell death, but functional changes. Affymetrix Gene arrays showed changes in the expression in a large number of gene families including cell death, inflammation and neurotransmitters in the hippocampus after both acceleration and penetration injuries. Exposure to the primary blast wave induced limited shifts in gene expression in the hippocampus. The most interesting findings were a downregulation of genes involved in neurogenesis and synaptic transmission. These experiments indicate that rotational acceleration may be a critical factor for DAI and other acute changes after blast TBI. The further exploration of the mechanisms of blast TBI will have to include a search for long-term effects. PMID:20493951

  3. Numerical and Experimental Investigations of Tsunami-Induced Sediment Transport

    NASA Astrophysics Data System (ADS)

    Young, Y.; Xiao, H.

    2007-05-01

    As demonstrated by the 2004 Indian Ocean Tsunami, high intensity wave runup and drawdown can mobilize substantial amount of sediment deposits. The resulting erosion and scour damage can undermine building foundations, roadways, sea walls, embankments, and may even lead to eventual collapse of the coastal structure. However, most previous models ignore the effect of tsunami-induced sediment transport and scour due to the complex physics and multiple scaling issues. In this work, a numerical model is presented for the simulation of solitary waves over a uniform sloped movable bed. The depth averaged nonlinear shallow water equations (SWEs) are used to model long waves, the wave profile gradient method is used to detect wave breaking, and the effect of energy-dissipation due to wave breaking is captured as a bore collapse. The effect of sediment transport is modeled via a passive scalar and is fully coupled with the SWEs to form a complete system. New forms of the erosion and deposition fluxes are introduced to account for the effect of the flow velocity, particle fall velocity, wave profile, and pore pressure gradient. The model is validated by comparing the numerical solutions to the measured bed changes obtained from the cross-shore sediment transport experiment under breaking solitary waves conducted by (Kobayashi & Lawrence 2004). To further validate the numerical model, two sets of experimental studies are planned for 2007. The first experimental study focuses on the effect of enhanced transport due to pore pressure gradients, and will be conducted at the 30-ft long flume in the hydraulics lab at the University of Hawaii using multiple grain sizes. The second experimental study focuses on tsunami-induced sediment transport, and will be conducted at the 160-ft long tsunami wave basin at Oregon State University using fine Oregon beach sand with D50=0.20mm. The experimental setups are shown, and scaling issues for the two movable bed physical models are discussed

  4. The therapeutic use of music for dyspnea and anxiety in patients with COPD who live at home.

    PubMed

    McBride, S; Graydon, J; Sidani, S; Hall, L

    1999-09-01

    The purposes of this repeated measures study were to examine the feasibility of using music as an intervention for dyspnea and anxiety in patients with chronic obstructive pulmonary disease (COPD) who live in their homes and to examine the effect of music on anxiety and dyspnea. Twenty-four participants who experienced dyspnea at least once a week were studied over a 5-week period. Baseline data were collected on Week 1. Measures of anxiety and dyspnea were taken on Week 2, prior to and immediately following the use of music. These measures were repeated on Week 5. There was a significant decrease in dyspnea following the use of music as reported in the music diary (p < .001). There was a significant decline in anxiety (p < .05) and dyspnea (p < .01) following the use of music on Week 2. There was no significant change in anxiety or dyspnea over the 5-week period. PMID:10690067

  5. Dyspnea as a Prognostic Factor in Patients with Non-Small Cell Lung Cancer

    PubMed Central

    Ban, Wooho; Lee, Jong Min; Ha, Jick Hwan; Yeo, Chang Dong; Kang, Hyeon Hui; Rhee, Chin Kook; Moon, Hwa Sik

    2016-01-01

    Purpose To investigate associations between dyspnea and clinical outcomes in patients with non-small cell lung cancer (NSCLC). Materials and Methods From 2001 to 2014, we retrospectively reviewed the prospective lung cancer database of St. Paul's Hospital at the Catholic University of Korea. We enrolled patients with NSCLC and evaluated symptoms of dyspnea using modified Medical Research Council (mMRC) scores. Also, we estimated pulmonary functions and analyzed survival data. Results In total, 457 NSCLC patients were enrolled, and 259 (56.7%) had dyspnea. Among those with dyspnea and whose mMRC scores were available (109 patients had no mMRC score), 85 (56.6%) patients had an mMRC score <2, while 65 (43.3%) had an mMRC score ≥2. Significant decreased pulmonary functions were observed in patients with dyspnea. In multivariate analysis, aging, poor performance status, advanced stage, low forced expiratory volume in 1 second (%), and an mMRC score ≥2 were found to be significant prognostic factors for patient survival. Conclusion Dyspnea could be a significant prognostic factor in patients with NSCLC. PMID:27401635

  6. Effect of anticipation triggered by a prior dyspnea experience on brain activity

    PubMed Central

    Nakai, Hideki; Tsujimoto, Kengo; Fuchigami, Takeshi; Ohmatsu, Satoko; Osumi, Michihiro; Nakano, Hideki; Fukui, Manami; Morioka, Shu

    2015-01-01

    [Purpose] Oxygenated hemoglobin (oxy-Hb) concentrations in the prefrontal cortex are closely associated with dyspnea. Dyspnea is influenced not only by physical activity, but also by visual stimuli, and several studies suggest that oxy-Hb concentrations change in response to certain external stimuli. However, the effects of internal psychological states on dyspnea have not been reported. This study explored the influence of anticipation triggered by previous episodes of dyspnea on brain activity. [Subjects] The subjects were 15 healthy volunteers with a mean age of 25.0 ± 3.0 years. [Methods] The subjects were shown a variety of photographs and instructed to expect breathing resistance matched to the affective nature of the particular photograph. After viewing the images, varying intensities of breathing resistance that were identical to, easier than, or harder than those shown in the images were randomly administered to the subjects; in fact, the image and resistance were identical 33% of the time and discordant 66% of the time. [Results] The concentrations of oxy-Hb in the right medial prefrontal cortex (rMPFC) increased significantly with an inspiratory pressure that was 30% of the maximum intensity in the subjects shown a pleasant image compared to the concentrations in subjects shown an unpleasant image. Moreover, rMPFC activity was significantly correlated with the magnitude of the dyspnea experienced. [Conclusion] These results suggest that a correlation exists between increased oxy-Hb in the rMPFC and the effects of expectations on dyspnea. PMID:25931697

  7. Combined Effect of Opioids and Corticosteroids for Alleviating Dyspnea in Terminal Cancer Patients: A Retrospective Review.

    PubMed

    Maeda, Tsuyoshi; Hayakawa, Toru

    2016-06-01

    Dyspnea is a prognostic factor that affects the quality of life of terminal cancer patients, and many reports have described opioid treatment for dyspnea alleviation. Here, we retrospectively evaluated differences in the effects of various opioids administered concomitantly with corticosteroids on dyspnea in 20 terminal-stage cancer patients (13 men, 7 women; mean age [range]: 71 [49-94] years) who received opioids concomitantly with corticosteroids. Effectiveness was assessed throughout administration using the Support Team Assessment Schedule, Japanese version (STAS-J), particularly the subscale indicating how strongly a patient is affected by symptoms. The effectiveness of combined opioid and corticosteroid therapy against dyspnea and the opioid dose comprised the primary and secondary foci, respectively. Among concomitantly treated patients, STAS-J scores at initiation (mean ± SD: 3.1 ± 0.24) and lowest recorded STAS-J scores (1.4 ± 0.22) differed significantly (P = .0034) among those receiving morphine, but not among those receiving oxycodone (P = .068) or fentanyl (P = .18). Concomitant opioid and corticosteroid treatment was associated with a ≥2-point STAS-J score improvement in 14/20 patients (effectiveness: 70%). The opioid dose did not significantly affect dyspnea alleviation. We conclude that concomitant opioid and corticosteroid treatment can effectively alleviate dyspnea in terminal cancer patients. PMID:27093633

  8. Foraminiferal survival after long term experimentally induced anoxia

    NASA Astrophysics Data System (ADS)

    Langlet, D.; Geslin, E.; Baal, C.; Metzger, E.; Lejzerowicz, F.; Riedel, B.; Zuschin, M.; Pawlowski, J.; Stachowitsch, M.; Jorissen, F. J.

    2013-06-01

    Anoxia has been successfully induced in four benthic chambers installed on the Northern Adriatic seafloor from 1 week to 10 months. To accurately determine whether benthic foraminifera can survive experimentally induced prolonged anoxia, the CellTrackerGreen method has been applied. Numerous individuals have been found living at all sampling times and at all sampling depths, showing that benthic foraminifera can survive up to 10 months of anoxia with co-occurring hydrogen sulphides. However, foraminiferal standing stocks decrease with sampling time in an irregular way. A large difference in standing stock between two cores samples in initial conditions indicates the presence of a large spatial heterogeneity of the foraminiferal faunas. An unexpected increase in standing stocks after 1 month is tentatively interpreted as a reaction to increased food availability due to the massive mortality of infaunal macrofaunal organisms. After this, standing stocks decrease again in a core sampled after 2 months of anoxia, to attain a minimum in the cores sampled after 10 months. We speculate that the trend of overall decrease of standing stocks is not due to the adverse effects of anoxia and hydrogen sulphides, but rather due to a continuous diminution of labile organic matter.

  9. Bedside Ultrasonography versus Brain Natriuretic Peptide in Detecting Cardiogenic Causes of Acute Dyspnea

    PubMed Central

    Golshani, Keihan; Esmailian, Mehrdad; Valikhany, Aniseh; Zamani, Majid

    2016-01-01

    Introduction: Acute dyspnea is a common cause of hospitalization in emergency departments (ED).Distinguishing the cardiac causes of acute dyspnea from pulmonary ones is a major challenge for responsible physicians in EDs. This study compares the characteristics of bedside ultrasonography with serum level of blood natriuretic peptide (BNP) in this regard. Methods: This diagnostic accuracy study compares bedside ultrasonography with serum BNP levels in differentiating cardiogenic causes of acute respiratory distress. Echocardiography was considered as the reference test. A checklist including demographic data (age and sex), vital signs, medical history, underlying diseases, serum level of BNP, as well as findings of chest radiography, chest ultrasonography, and echocardiography was filled for all patients with acute onset of dyspnea. Screening characteristics of the two studied methods were calculated and compared using SPSS software, version 20. Results: 48 patients with acute respiratory distress were evaluated (50% female). The mean age of participants was 66.94 ± 16.33 (28-94) years. Based on the results of echocardiography and final diagnosis, the cause of dyspnea was cardiogenic in 20 (41.6%) cases. Bedside ultrasonography revealed the cardiogenic cause of acute dyspnea in 18 cases (0 false positive) and BNP in 44 cases (24 false positives). The area under the ROC curve for bedside ultrasonography and BNP for differentiating the cardiogenic cause of dyspnea were 86.4 (95% CI: 74.6-98.3) and 66.3 (95% CI: 49.8-89.2), respectively (p = 0.0021). Conclusion: It seems that bedside ultrasonography could be considered as a helpful and accurate method in differentiating cardiogenic causes of acute dyspnea in emergency settings. Nevertheless, more study is needed to make a runaway algorithm to evaluate patients with respiratory distress using bedside ultrasonography, which leads to rapid therapeutic decisions in a short time. PMID:27299143

  10. Pentamidine-induced dysglycaemia: experimental models in the rat.

    PubMed

    Assan, R; Assan, D; Delaby, J; Debussche, X; Toublanc, M

    1993-01-01

    In order to analyse further the pathophysiology of pentamidine effects on blood glucose regulation, the following experimental models were established in rats: impairment of the renal function, bile duct ligation, inhibition of the P450 cytochrome enzyme system. In otherwise intact rats, 7.5 mg/day pentamidine was well tolerated whereas doses of 15 mg/day induced severe, relapsing and eventually lethal hypoglycaemia within a few days. Induction of a renal insufficiency of graded severity by treatment with gentamycin, subtotal nephrectomy and total bilateral nephrectomy resulted in repetitive, severe (sometimes lethal) hypoglycaemia, alternating with hyperglycaemia, glucosuria and ketonuria in pentamidine-treated rats (7.5 mg/d). No long-standing insulin-dependent diabetes was observed. In the dysglycemic animals, plasma insulin levels were inappropriate to the concomitant glycaemia; no stimulation was obtained by i.v. glucose. Glucagon levels were higher than normal, suppressible by i.v. glucose, responsive to IV arginine and to hypoglycaemia. Dysglycemic events were more frequent and marked in the rats with the most severe renal functional derangement. They were more frequent in the rats treated with pentamidine mesylate than in those treated with the isethionate salt. Control uremic rats (free of pentamidine) remained euglycaemic. The islets of Langerhans displayed severe vascular congestion and degranulation and necrosis of the B cells, while the non B cells (and particularly the A cells) were intact. Exocrine pancreatitis was occasionally observed in the most severely uremic rats. In contrast with uremic rats, neither surgical ligation of choledocus, nor treatment by P450 cytochrome inhibitors (particularly ketoconazole) precipitated dysglycaemia in the pentamidine-treated rats. These experimental data: 1) strengthen the concept of inappropriate insulin release from pentamidine-lesioned islet B cells due to pentamidine accumulation; 2) indicate a predominant

  11. The Effects of Experimentally Induced Adelphophagy in Gastropod Embryos

    PubMed Central

    Thomsen, Olaf; Collin, Rachel; Carrillo-Baltodano, Allan

    2014-01-01

    Adelphophagy, development where embryos grow large by consuming morphologically distinct nutritive embryos or their own normal siblings is widespread but uncommon among animal phyla. Among invertebrates it is particularly common in some families of marine gastropods and segmented worms, but rare or unknown in other closely related families. In calyptraeid gastropods phylogenetic analysis indicates that adelphophagy has arisen at least 9 times from species with planktotrophic larval development. This pattern of frequent parallel evolution of adelphophagy suggests that the embryos of planktotrophic species might be predisposed to evolve adelphophagy. Here we used embryos of three species of planktotrophic calyptraeids, one from each of three major genera in the family (Bostrycapulus, Crucibulum, and Crepidula), to answer the following 3 questions: (1) Can embryos of species with planktotrophic development benefit, in terms of pre-hatching growth, from the ingestion of yolk and tissue from experimentally damaged siblings? (2) Does ingestion of this material from damaged siblings increase variation in pre-hatching size? and (3) Does this experimentally induced adelphophagy alter the allometry between the velum and the shell, increasing morphological similarity to embryos of normally adelphophagic species? We found an overall increase in shell length and velum diameter when embryos feed on damaged siblings within their capsules. There was no detectable increase in variation in shell length or velum diameter, or changes in allometry. The overall effect of our treatment was small compared to the embryonic growth observed in naturally adelphophagic development. However each embryo in our experiment probably consumed less than one sibling on average, whereas natural adelphophages often each consume 10–30 or more siblings. These results suggest that the ability to consume, assimilate, and benefit from yolk and tissue of their siblings is widespread across calyptraeids

  12. 4-nitroquinoline-1-oxide induced experimental oral carcinogenesis.

    PubMed

    Kanojia, Deepak; Vaidya, Milind M

    2006-08-01

    Human oral cancer is the sixth largest group of malignancies worldwide and single largest group of malignancies in the Indian subcontinent. Seventy percent of premalignant cancers appear from premalignant lesions. Only 8-10% of these lesions finally turn into malignancy. The appearance of these premalignant lesions is one distinct feature of human oral cancer. At present there is dearth of biomarkers to identify which of these lesions will turn into malignancy. Regional lymph node metastasis and locoregional recurrence are the major factors responsible for the limited survival of patients with oral cancer. Paucity of early diagnostic and prognostic markers is one of the contributory factors for higher mortality rates. Cancer is a multistep process and because of constrain in availability of human tissues from multiple stages of oral carcinogenesis including normal tissues, animal models are being widely used, aiming for the development of diagnostic and prognostic markers. A number of chemical carcinogens like coal tar, 20 methyl cholanthrene (20MC), 9,10-dimethyl-1,2-benzanthracene (DMBA) and 4-nitroquinoline-1-oxide (4NQO) have been used in experimental oral carcinogenesis. However, 4NQO is the preferred carcinogen apart from DMBA in the development of experimental oral carcinogenesis. 4NQO is a water soluble carcinogen, which induces tumors predominantly in the oral cavity. It produces all the stages of oral carcinogenesis and several lines of evidences suggest that similar histological as well as molecular changes are observed in the human system. In the present review an attempt has been made to collate the information available on mechanisms of action of 4NQO, studies carried out for the development of biomarkers and chemopreventives agents using 4NQO animal models. PMID:16448841

  13. Erythropoietin is a hypoxia inducible factor-induced protective molecule in experimental autoimmune neuritis.

    PubMed

    Luo, Bangwei; Jiang, Man; Yang, Xiaofeng; Zhang, Zhiyuan; Xiong, Jian; Schluesener, Hermann J; Zhang, Zhiren; Wu, Yuzhang

    2013-08-01

    Experimental autoimmune neuritis (EAN), an autoantigen-specific T-cell-mediated disease model for human demyelinating inflammatory disease of the peripheral nervous system, is characterized by self-limitation. Here we investigated the regulation and contribution of erythropoietin (EPO) in EAN self-limitation. In EAN sciatic nerves, hypoxia, and protein and mRNA levels of hypoxia-inducible factor 1α (HIF-1α), HIF-2α, EPO and EPO receptor (EPOR) were induced in parallel at disease peak phase but reduced at recovery periods. Further, the deactivation of HIF reduced EAN-induced EPO/EPOR upregulation in EAN, suggesting the central contribution of HIF to EPO/EPOR induction. The deactivation of EPOR signalling exacerbated EAN progression, implying that endogenous EPO contributed to EAN recovery. Exogenous EPO treatment greatly improved EAN recovery. In addition, EPO was shown to promote Schwann cell survival and myelin production. In EAN, EPO treatment inhibited lymphocyte proliferation and altered helper T cell differentiation by inducing increase of Foxp3(+)/CD4(+) regulatory T cells and decrease of IFN-γ(+)/CD4(+) Th1 cells. Furthermore, EPO inhibited inflammatory macrophage activation and promoted its phagocytic activity. In summary, our data demonstrated that EPO was induced in EAN by HIF and contributed to EAN recovery, and endogenous and exogenous EPO could effectively suppress EAN by attenuating inflammation and exerting direct cell protection, indicating that EPO contributes to the self-recovery of EAN and could be a potent candidate for treatment of autoimmune neuropathies. PMID:23603807

  14. The Cell Nucleus in Physiological and Experimentally Induced Hypometabolism

    NASA Astrophysics Data System (ADS)

    Malatesta, M.

    The main problem for manned space mission is, at present, represented by the mass penalty associated to the human presence. An efficient approach could be the induction of a hypometabolic stasis in the astronauts, thus drastically reducing the physical and psychological requirements of the crew. On the other hand, in the wild, a reduction in resource consumptions physiologi- cally occurs in certain animals which periodically enter hibernation, a hypometabolic state in which both the energy need and energy offer are kept at a minimum. During the last twelve years, we have been studying different tissues of hibernating dormice, with the aim of analyzing their features during the euthermia -hibernation-arousal cycle as well as getting insight into the mechanisms allowing adaptation to hypometabolism. We paid particular attention to the cell nucleus, as it is the site of chief metabolic functions, such as DNA replication and RNA transcription. Our observations revealed no significant modification in the basic features of cell nuclei during hibernation; however, the cell nuclei of hibernating dormice showed unusual nuclear bodies containing molecules involved in RNA pathways. Therefore, we supposed that they could represent storage/assembly sites of several factors for processing some RNA which could be slowly synthesised during hibernation and rapidly and abundantly released in early arousal in order to meet the increased metabolic needs of the cell. The nucleolus also underwent structural and molecular modifications during hibernation, maybe to continue important nucleolar functions, or, alternatively, permit a most efficient reactivation upon arousal. On the basis of the observations made in vivo , we recently tried to experimentally induce a reversible hypometabolic state in in vitro models, using cell lines derived from hibernating and non-hibernating species. By administering the synthetic opioid DADLE, we could significantly reduce both RNA transcrip- tion and

  15. Confabulation versus experimentally induced false memories in Korsakoff patients.

    PubMed

    Van Damme, Ilse; d'Ydewalle, Géry

    2010-09-01

    The present study focuses on both the clinical symptom of confabulation and experimentally induced false memories in patients suffering from Korsakoff's syndrome. Despite the vast amount of case studies of confabulating patients and studies investigating false memories in the Deese-Roediger-McDermott (DRM) paradigm, the nature of Korsakoff patients' confabulatory behaviour and its association with DRM false memories have been rarely examined. Hence, the first aim of the present study was to evaluate confabulatory responses in a large sample of chronic Korsakoff patients and matched controls by means of the Dalla Barba Confabulation Battery. Second, the association between (provoked) confabulation and the patients' DRM false recognition performance was investigated. Korsakoff patients mainly confabulated in response to questions about episodic memory and questions to which the answer was unknown. A positive association was obtained between confabulation and the tendency to accept unstudied distractor words as being old in the DRM paradigm. On the other hand, there was a negative association between confabulation and false recognition of critical lures. The latter could be attributed to the importance of strategic retrieval at delayed memory testing. PMID:19930792

  16. Standardised Models for Inducing Experimental Peritoneal Adhesions in Female Rats

    PubMed Central

    Kraemer, Bernhard; Wallwiener, Christian; Rajab, Taufiek K.; Brochhausen, Christoph; Wallwiener, Markus; Rothmund, Ralf

    2014-01-01

    Animal models for adhesion induction are heterogeneous and often poorly described. We compare and discuss different models to induce peritoneal adhesions in a randomized, experimental in vivo animal study with 72 female Wistar rats. Six different standardized techniques for peritoneal trauma were used: brushing of peritoneal sidewall and uterine horns (group 1), brushing of parietal peritoneum only (group 2), sharp excision of parietal peritoneum closed with interrupted sutures (group 3), ischemic buttons by grasping the parietal peritoneum and ligating the base with Vicryl suture (group 4), bipolar electrocoagulation of the peritoneum (group 5), and traumatisation by electrocoagulation followed by closure of the resulting peritoneal defect using Vicryl sutures (group 6). Upon second look, there were significant differences in the adhesion incidence between the groups (P < 0.01). Analysis of the fraction of adhesions showed that groups 2 (0%) and 5 (4%) were significantly less than the other groups (P < 0.01). Furthermore, group 6 (69%) was significantly higher than group 1 (48%) (P < 0.05) and group 4 (47%) (P < 0.05). There was no difference between group 3 (60%) and group 6 (P = 0.2). From a clinical viewpoint, comparison of different electrocoagulation modes and pharmaceutical adhesion barriers is possible with standardised models. PMID:24809049

  17. Regulation of Adenosine Deaminase on Induced Mouse Experimental Autoimmune Uveitis.

    PubMed

    Liang, Dongchun; Zuo, Aijun; Zhao, Ronglan; Shao, Hui; Kaplan, Henry J; Sun, Deming

    2016-03-15

    Adenosine is an important regulator of the immune response, and adenosine deaminase (ADA) inhibits this regulatory effect by converting adenosine into functionally inactive molecules. Studies showed that adenosine receptor agonists can be anti- or proinflammatory. Clarification of the mechanisms that cause these opposing effects should provide a better guide for therapeutic intervention. In this study, we investigated the effect of ADA on the development of experimental autoimmune uveitis (EAU) induced by immunizing EAU-prone mice with a known uveitogenic peptide, IRBP1-20. Our results showed that the effective time to administer a single dose of ADA to suppress induction of EAU was 8-14 d postimmunization, shortly before EAU expression; however, ADA treatment at other time points exacerbated disease. ADA preferentially inhibited Th17 responses, and this effect was γδ T cell dependent. Our results demonstrated that the existing immune status strongly influences the anti- or proinflammatory effects of ADA. Our observations should help to improve the design of ADA- and adenosine receptor-targeted therapies. PMID:26856700

  18. Albendazole therapy for experimentally induced Paragonimus kellicotti infection in cats.

    PubMed

    Dubey, J P; Hoover, E A; Stromberg, P C; Toussant, M J

    1978-06-01

    The effect of albendazole therapy was studied in 6 cats with pulmonary paragonimiasis induced by experimental inoculation of metacercariae (25/cat) of Paragonimus kellicotti. At 76 to 101 days after they were inoculated, 5 cats were administered an oral aqueous suspension of albendazole in 2 divided doses totaling 20 mg (2 cats), 50 mg (1 cat), or 100 mg (2 cats)/kg of body weight each day for 14 to 21 days. The 6th cat (control) was not administered albendazole. Nine days after cats were given the 50- and 100-mg/kg dosages, Paragonimus ova were not seen in the feces of 3 cats. There was marked reduction in ova production in the feces of the 2 cats administered 20 mg/kg of albendazole. Live flukes were not recovered from the lungs of 3 cats necropsied 4 or 5 weeks after dosing with 50 or 100 mg/kg, but the lungs of the 2 cats administered 20 mg of albendazole/kg yielded 9 and 7 apparently viable flukes. Seventeen live flukes were recovered from the control cat not treated with albendazole. In 4 noninoculated normal cats administered 20 mg (1 cat), 100 mg (1 cat), and 200 mg (2 cats) of albendazole/kg of body weight each day for 14 days, there were no gross or microscopic lesions attributable to the drug. PMID:666077

  19. Dyspnea and quality of life indicators in hospice patients and their caregivers

    PubMed Central

    Moody, Linda E; McMillan, Susan

    2003-01-01

    This study describes the assessment of dyspnea, symptom distress, and quality of life measures in 163 hospice patients with cancer who reported dyspnea. Mean age of the hospice patient sample was 70.22 years and 61.86 for caregivers (65% were spouses). The majority of patients and caregivers were white: 87%, 63% of the patients were male while 78% of caregivers were female. Mean dyspnea intensity as reported by patients was 4.52 (SD 2.29) and caregivers, 4.39 (SD 2.93). Patients' and caregivers' ratings of the patient's dyspnea intensity revealed no significant differences in ratings thus verifying that caregivers can assess dyspnea severity accurately. Patients' perceived quality of life ratings were not significantly correlated with ratings of their caregivers' perceived quality of life. For patients, symptom distress and education were significant predictors of variance in quality of life (R2 = .35, p = .04). However, mastery, symptom distress, age, and education were found to be significant predictors of variance in quality of life of caregivers (R2 = .40, p = .02). PMID:12740034

  20. Sequential occurrence of dyspnea at the end of life in palliative care, according to the underlying cancer

    PubMed Central

    Guirimand, Frédéric; Sahut d'izarn, Marine; Laporte, Lucy; Francillard, Marie; Richard, Jean-François; Aegerter, Philippe

    2015-01-01

    Dyspnea is a symptom that severely affects the quality of life of terminally ill patients. Its frequency differs considerably between studies. We aimed to characterize the frequency of dyspnea in a palliative care hospital (PCH) and to identify factors predisposing to dyspnea, particularly during the very last days of life, as a function of the underlying disease. Episodes of dyspnea were identified by the computerized extraction of prospectively collected data from the reports of care assistants or from medical observations recorded in the medical files for all stays at our PCH during the last 6 years. There were 6455 hospital stays, 88% ending in the death of the patient; 13,282 episodes of dyspnea were recorded during 2608 hospital stays (40%). Dyspnea was more frequently observed in cases of cancer than in other conditions (RR = 1.30; 95% CI: 1.14–1.48). Pulmonary metastasis increased the risk of dyspnea from 37% to 51% (RR = 1.37; 95% CI: 1.29–1.46). Dyspnea frequency varied with the primary cancer site, from 24% (brain cancer) to 60% (esophageal cancer). The data for cancer patients staying for more than 6 days who subsequently died indicated that 8% of patients experienced dyspnea exclusively during the last 4 days of the life, independently of the site of the primary cancer. Dyspnea during the last few days of life requires systematic assessment. Exclusively terminal dyspnea should be distinguished from more precocious dyspnea, as the pathophysiological mechanisms and treatments of these two forms are probably different. PMID:25644607

  1. Sequential occurrence of dyspnea at the end of life in palliative care, according to the underlying cancer.

    PubMed

    Guirimand, Frédéric; Sahut d'izarn, Marine; Laporte, Lucy; Francillard, Marie; Richard, Jean-François; Aegerter, Philippe

    2015-04-01

    Dyspnea is a symptom that severely affects the quality of life of terminally ill patients. Its frequency differs considerably between studies. We aimed to characterize the frequency of dyspnea in a palliative care hospital (PCH) and to identify factors predisposing to dyspnea, particularly during the very last days of life, as a function of the underlying disease. Episodes of dyspnea were identified by the computerized extraction of prospectively collected data from the reports of care assistants or from medical observations recorded in the medical files for all stays at our PCH during the last 6 years. There were 6455 hospital stays, 88% ending in the death of the patient; 13,282 episodes of dyspnea were recorded during 2608 hospital stays (40%). Dyspnea was more frequently observed in cases of cancer than in other conditions (RR = 1.30; 95% CI: 1.14-1.48). Pulmonary metastasis increased the risk of dyspnea from 37% to 51% (RR = 1.37; 95% CI: 1.29-1.46). Dyspnea frequency varied with the primary cancer site, from 24% (brain cancer) to 60% (esophageal cancer). The data for cancer patients staying for more than 6 days who subsequently died indicated that 8% of patients experienced dyspnea exclusively during the last 4 days of the life, independently of the site of the primary cancer. Dyspnea during the last few days of life requires systematic assessment. Exclusively terminal dyspnea should be distinguished from more precocious dyspnea, as the pathophysiological mechanisms and treatments of these two forms are probably different. PMID:25644607

  2. New physiological insights into dyspnea and exercise intolerance in chronic obstructive pulmonary disease patients.

    PubMed

    Laveneziana, Pierantonio; Guenette, Jordan A; Webb, Katherine A; O'Donnell, Denis E

    2012-12-01

    Dyspnea and reduced exercise tolerance are common consequences of chronic obstructive pulmonary disease (COPD) and contribute importantly to poor perceived health status. While the origins of dyspnea and reduced exercise tolerance are complex and multifactorial, there is increasing evidence that lung hyperinflation is an important contributory factor that can be targeted for treatment. In this review, the authors summarize current concepts of the origin and clinical and physiological consequences of both static and dynamic lung hyperinflation in COPD. In particular, they review recent studies that have examined the role of lung hyperinflation in dyspnea causation during exacerbations and physical activity in COPD. Finally, current concepts of the mechanisms of symptom relief and improved exercise tolerance following pharmacological lung volume reduction are reviewed. PMID:23234451

  3. Anticoccidial effect of mananoligosacharide against experimentally induced coccidiosis in broiler.

    PubMed

    Chand, Naila; Faheem, Hassan; Khan, Rifat Ullah; Qureshi, Muhammad Subhan; Alhidary, Ibrahim A; Abudabos, Alaeldein M

    2016-07-01

    The aim of this study was to find the effect of mananoligosacharide (MOS) in comparison with amprolium hydrochloride on performance and integrity of gut in experimentally induced coccidiosis in broiler. A total of 300, day-old male broiler chickens (Ross 308) was randomly allocated to four treatments. Each group was further divided into five replicates of 15 birds each. Group A was kept as control; group B was contaminated with Eimeria tenella, while groups C and D were infected with E. tenella and treated with MOS (0.8 g/kg feed) and anticoccidial drug, amprolium hydrochloride (12 g/100 l water), respectively. The results showed that weight gain, feed intake, and feed conversion ratio (FCR) were significantly higher (P < 0.05) in infected + MOS-treated group compared to the other groups. The result of oocyte per gram (OPG) was significantly higher (P < 0.05) in the group infected with coccidiosis during 5th, 7th, 10th, and 12th day post infection (dpi). Furthermore, the OPG was significantly lower (P < 0.05) in infected groups treated with MOS and amprolium at the studied periods (5, 7, and 10 dpi). At 12 dpi, the infected group treated with MOS showed significantly lower OPG compared to the other groups suggesting the effectiveness of MOS in comparison to amprolium. The result of pinpoint hemorrhages, thickness of cecal wall, bloody fecal contents, and mucoid contents in the cecum were significant highly (P < 0.05) in birds fed with infected oocytes. It was also noted that the differences were not significant in these parameters between amprolium and MOS-treated birds showing the effectiveness of the prebiotic agent. It was concluded from the results of the present study that MOS improved growth performance and reversed the lesions of E. tenella. PMID:27068898

  4. Experimental validation of a numerical model for subway induced vibrations

    NASA Astrophysics Data System (ADS)

    Gupta, S.; Degrande, G.; Lombaert, G.

    2009-04-01

    This paper presents the experimental validation of a coupled periodic finite element-boundary element model for the prediction of subway induced vibrations. The model fully accounts for the dynamic interaction between the train, the track, the tunnel and the soil. The periodicity or invariance of the tunnel and the soil in the longitudinal direction is exploited using the Floquet transformation, which allows for an efficient formulation in the frequency-wavenumber domain. A general analytical formulation is used to compute the response of three-dimensional invariant or periodic media that are excited by moving loads. The numerical model is validated by means of several experiments that have been performed at a site in Regent's Park on the Bakerloo line of London Underground. Vibration measurements have been performed on the axle boxes of the train, on the rail, the tunnel invert and the tunnel wall, and in the free field, both at the surface and at a depth of 15 m. Prior to these vibration measurements, the dynamic soil characteristics and the track characteristics have been determined. The Bakerloo line tunnel of London Underground has been modelled using the coupled periodic finite element-boundary element approach and free field vibrations due to the passage of a train at different speeds have been predicted and compared to the measurements. The correspondence between the predicted and measured response in the tunnel is reasonably good, although some differences are observed in the free field. The discrepancies are explained on the basis of various uncertainties involved in the problem. The variation in the response with train speed is similar for the measurements as well as the predictions. This study demonstrates the applicability of the coupled periodic finite element-boundary element model to make realistic predictions of the vibrations from underground railways.

  5. Sinus Venosus Atrial Septal Defect as a Cause of Palpitations and Dyspnea in an Adult: A Diagnostic Imaging Challenge

    PubMed Central

    Donovan, Michael S.; Kassop, David; Liotta, Robert A.; Hulten, Edward A.

    2015-01-01

    Sinus venosus atrial septal defects (SV-ASD) have nonspecific clinical presentations and represent a diagnostic imaging challenge. Transthoracic echocardiography (TTE) remains the initial diagnostic imaging modality. However, detection rates have been as low as 12%. Transesophageal echocardiography (TEE) improves diagnostic accuracy though it may not detect commonly associated partial anomalous pulmonary venous return (PAPVR). Cardiac magnetic resonance (CMR) imaging provides a noninvasive, highly sensitive and specific imaging modality of SV-ASD. We describe a case of an adult male with exercise-induced, paroxysmal supraventricular tachycardia who presented with palpitations and dyspnea. Despite nondiagnostic imaging results on TTE, CMR proved to be instrumental in visualizing a hemodynamically significant SV-ASD with PAPVR that ultimately led to surgical correction. PMID:25705227

  6. Development of a Barthel Index based on dyspnea for patients with respiratory diseases

    PubMed Central

    Vitacca, Michele; Paneroni, Mara; Baiardi, Paola; De Carolis, Vito; Zampogna, Elisabetta; Belli, Stefano; Carone, Mauro; Spanevello, Antonio; Balbi, Bruno; Bertolotti, Giorgio

    2016-01-01

    Background As Barthel Index (BI) quantifies motor impairment but not breathlessness, the use of only this index could underestimate disability in chronic respiratory disease (CRD). To our knowledge, no study evaluates both motor and respiratory disability in CRD during activities of daily living (ADLs) simultaneously and with a unique tool. The objective of this study was to propose for patients with CRD an additional tool for dyspnea assessment during ADLs based on BI items named Barthel Index dyspnea. Methods Comprehensibility, reliability, internal consistency, validity, responsiveness, and ability to differentiate between disease groups were assessed on 219 subjects through an observational study performed in an in-hospital rehabilitation setting. Results Good comprehensibility, high reliability (interrater intraclass correlation coefficient was 0.93 [95% confidence interval 0.892–0.964] and test–retest intraclass correlation coefficient was 0.99 [95% confidence interval 0.983–0.994]), good internal consistency (Cronbach’s alpha 0.89), strong concurrent validity with 6 minute walking distance (Pearson r=−0.538, P<0.001) and Medical Research Council (Spearman rS=0.70, P<0.001), good responsiveness after rehabilitation (P<0.001), and good appropriateness of the index were found evidencing patients with different dyspnea severity. Divergent validity showed weak correlation (Pearson r=−0.38) comparing Barthel Index dyspnea and BI. Conclusion The BI based on dyspnea perception proved to be reliable, sensitive, and adequate as a tool for measuring the level of dyspnea perceived in performing basic daily living activities. A unique instrument simultaneously administered may provide a global assessment of disability during ADLs incorporating both motor and respiratory aspects. PMID:27354778

  7. [New approaches to primary differentiation of dyspnea in patients with pulmonary and cardiac pathology].

    PubMed

    Martynenko, T I; Paraeva, O S; Dronov, S V; Shoikhet, Ia N

    2014-01-01

    This study was aimed at searching new instruments for primary differentiation of dyspnea associated with lung or heart pathology. The study consisted of 3 stages and included analysis of "glossary dyspnea" of 482 patients aged 18-90yr. Stages i and II involved 359 patients with the known diagnosis: chronic obstructive pulmonary disease (COPD) (n=114, 31.8%), bronchial asthma (BA) (n=134, 3 7.3%), chronic heart failure (CHF) unrelated to lung pathology (n=111, 30.9%). The patients were 205 (57.1%) men and 154 (42.9%) women. Stage III involved 123 patients complaining ofdyspneapresumably ofpulmnonary or cardiac origin. 75 (61.0%) of these patients were men, 48 (39.0%) women aged 18-89 yr. Subsequent comprehensive diagnostics revealed BA in 47 (38.2%), COPD in 46 (37.4%), CHF in 30 (24.4%) patents. Stage I was designed to evaluate the dyspnea language based on the frequency of the phases of glossary dyspnea (Simon et al., 1999) and Fisher's Z criterion. It permitted to create the modified glossary dyspnea (MGD) consisting of 11i phrases and 7 clusters that revealed statistically significant differences between patients with BA, COPD, and CHE At stage II, we developed the model for estimating the probability of a priori diagnosis (PPD) as a possible cause of dyspnea based on the data of MGD and modified Bayesian classificator. At stage III, the PPD model was verified using blindly selected patients. Prior to verification, the patients filled MGD. The final diagnosis was specified in accordance with the national recommendations. on diagnostics of BA, COPD and CHE Comparison of the frequency of coincidence between preliminary (a priori) and definitive (a posteriori) diagnoses made it possible to evaluate sensitivity and specificity of the PPD model for BA, COPD, and CHF unrelated to lung pathology. PMID:25790711

  8. Opioids, Exertion, and Dyspnea: A Review of the Evidence.

    PubMed

    Johnson, Miriam J; Hui, David; Currow, David C

    2016-03-01

    The aim of this paper is to review the evidence for a role for opioids as an intervention for exertion induced breathlessness with regard to exercise tolerance and breathlessness intensity. Current knowledge about exogenous opioids in exertion-induced breathlessness due to disease comes from a variety of phase 2 feasibility or pilot designs with differing duration, doses, drugs, exercise regimes, underlying aetiologies, and outcome measures. They provide interesting data but firm conclusions for either breathlessness severity or exercise endurance cannot be drawn. There are no adequately powered phase 3 trials of opioids which show improved exercise tolerance and/or exertion induced breathlessness. Low dose oral morphine seems well tolerated by most, and is beneficial for breathlessness intensity. Current work to investigate the effect on exercise tolerance is ongoing. PMID:25294225

  9. [Three cases of inhalation of household pyrethroid and metoxadiazone insecticides with remarkable dyspnea].

    PubMed

    Taguchi, Shigemasa; Shimizu, Keiki; Yokote, Ryo; Uchiyama, Munehito; Sekii, Hajime; Kiyota, Kazuya

    2006-04-01

    Household insecticides containing pyrethroids as their active ingredient are widely used in Japan. We encountered three cases of dyspnea caused by insecticides containing pyrethroids and metoxadiazone. The first case was a 52-year-old woman who suffered with dyspnea after breathing interior air following use of a fumigating insecticide. Although bronchoscopy revealed laryngotracheal edema, symptoms improved following administration of hydrocortisone and midazolam. Although the second case was a 63-year-old man who suffered with dyspnea as a result of direct aerosol insecticide inhalation due to missuse, symptoms had dissipated when the patient arrived at the hospital. The third case was a 20-year-old man with allergies who presented with dyspnea due to exposure to an aerosol insecticide three days after use. An allergic mechanism was thought to be involved. Reports of respiratory symptoms and allergic reactions caused by inhalation of pyrethroids are rare. Although the levels of exposure were low in all three cases compared to oral lethal dosage, these cases presented with serious respiratory symptoms, thus suggesting the need for further considerations regarding latent cases and safety. PMID:16715905

  10. Activity limitation and exertional dyspnea in adult asthmatic patients: What do we know?

    PubMed

    Vermeulen, François; Garcia, Gilles; Ninane, Vincent; Laveneziana, Pierantonio

    2016-08-01

    Limitation of activity is the most cited symptom described by uncontrolled asthma patients. Assessment of activity limitation can be undertaken through several ways, more or less complex, subjective or objective. Yet little is known about the link between patients sensations and objective measurements. The present review reports the current knowledge regarding activity limitation and symptom perception (i.e., exertional dyspnea) in adult patients with asthma. This work is based on references indexed by PubMed, irrespective of the year of publication. Overall, patients with stable asthma do not have a more sedentary lifestyle than healthy subjects. However, during a cycle ergometric test, the maximal load is reduced when FEV1, FVC and muscle strengths are decreased. Additionally, during the six-minute walking test, mild asthma patients walk less than healthy subjects even if the minimal clinically important difference is not reached. The major complaint of asthma patients when exercising is dyspnea that is mainly related to the inspiratory effort and also to dynamic hyperinflation in some circumstances. Finally, the administration of bronchodilator does not improve the ventilatory pattern and the exercise capacity of asthma patients and little is known on its effect on exertional dyspnea. The present review allows to conclude that until now there is no gold standard test allowing the objective assessment of "activity limitation and exertional dyspnea" in asthma patients. PMID:27492522

  11. A 57-Year-Old Man With Insidious Dyspnea and Nonpleuritic Chest and Back Pain.

    PubMed

    Nakamura, Kenta; Alba, George A; Scheske, Jonathan A; Meyersohn, Nandini M; Stone, James R; Vlahakes, Gus J; Wright, Cameron D; Ghoshhajra, Brian B; Dudzinski, David M

    2016-08-01

    A 57-year-old man with a history of DVT and pulmonary embolism, transient ischemic attacks, prior 60 pack-year smoking history, and oxygen-dependent COPD presented with insidiously worsening dyspnea associated with new pleuritic chest and back pain. PMID:27502992

  12. Protein S deficiency present in a pregnant woman with dyspnea, abdominal pains, restlessness, agitation and hypofibrinogenemia.

    PubMed

    Umazume, Takeshi; Morikawa, Mamoru; Yamada, Takahiro; Akaishi, Rina; Koyama, Takahiro; Minakami, Hisanori

    2015-04-01

    Hypofibrinogenemia is rare in pulmonary thromboembolism. A pregnant woman with dyspnea, abdominal pain, restlessness, agitation and protein S deficiency exhibited normal blood oxygenation and high D-dimer (370 μg/mL) and undetectable fibrinogen levels in the blood. The pathogenesis responsible for present findings may have some features similar to amniotic fluid embolism. PMID:25914811

  13. Physiological mechanisms of dyspnea during exercise with external thoracic restriction: role of increased neural respiratory drive.

    PubMed

    Mendonca, Cassandra T; Schaeffer, Michele R; Riley, Patrick; Jensen, Dennis

    2014-03-01

    We tested the hypothesis that neuromechanical uncoupling of the respiratory system forms the mechanistic basis of dyspnea during exercise in the setting of "abnormal" restrictive constraints on ventilation (VE). To this end, we examined the effect of chest wall strapping (CWS) sufficient to mimic a "mild" restrictive lung deficit on the interrelationships between VE, breathing pattern, dynamic operating lung volumes, esophageal electrode-balloon catheter-derived measures of the diaphragm electromyogram (EMGdi) and the transdiaphragmatic pressure time product (PTPdi), and sensory intensity and unpleasantness ratings of dyspnea during exercise. Twenty healthy men aged 25.7 ± 1.1 years (means ± SE) completed symptom-limited incremental cycle exercise tests under two randomized conditions: unrestricted control and CWS to reduce vital capacity (VC) by 21.6 ± 0.5%. Compared with control, exercise with CWS was associated with 1) an exaggerated EMGdi and PTPdi response; 2) no change in the relationship between EMGdi and each of tidal volume (expressed as a percentage of VC), inspiratory reserve volume, and PTPdi, thus indicating relative preservation of neuromechanical coupling; 3) increased sensory intensity and unpleasantness ratings of dyspnea; and 4) no change in the relationship between increasing EMGdi and each of the intensity and unpleasantness of dyspnea. In conclusion, the increased intensity and unpleasantness of dyspnea during exercise with CWS could not be readily explained by increased neuromechanical uncoupling but likely reflected the awareness of increased neural respiratory drive (EMGdi) needed to achieve any given VE during exercise in the setting of "abnormal" restrictive constraints on tidal volume expansion. PMID:24356524

  14. Physiological mechanisms of dyspnea during exercise with external thoracic restriction: Role of increased neural respiratory drive

    PubMed Central

    Mendonca, Cassandra T.; Schaeffer, Michele R.; Riley, Patrick

    2013-01-01

    We tested the hypothesis that neuromechanical uncoupling of the respiratory system forms the mechanistic basis of dyspnea during exercise in the setting of “abnormal” restrictive constraints on ventilation (VE). To this end, we examined the effect of chest wall strapping (CWS) sufficient to mimic a “mild” restrictive lung deficit on the interrelationships between VE, breathing pattern, dynamic operating lung volumes, esophageal electrode-balloon catheter-derived measures of the diaphragm electromyogram (EMGdi) and the transdiaphragmatic pressure time product (PTPdi), and sensory intensity and unpleasantness ratings of dyspnea during exercise. Twenty healthy men aged 25.7 ± 1.1 years (means ± SE) completed symptom-limited incremental cycle exercise tests under two randomized conditions: unrestricted control and CWS to reduce vital capacity (VC) by 21.6 ± 0.5%. Compared with control, exercise with CWS was associated with 1) an exaggerated EMGdi and PTPdi response; 2) no change in the relationship between EMGdi and each of tidal volume (expressed as a percentage of VC), inspiratory reserve volume, and PTPdi, thus indicating relative preservation of neuromechanical coupling; 3) increased sensory intensity and unpleasantness ratings of dyspnea; and 4) no change in the relationship between increasing EMGdi and each of the intensity and unpleasantness of dyspnea. In conclusion, the increased intensity and unpleasantness of dyspnea during exercise with CWS could not be readily explained by increased neuromechanical uncoupling but likely reflected the awareness of increased neural respiratory drive (EMGdi) needed to achieve any given VE during exercise in the setting of “abnormal” restrictive constraints on tidal volume expansion. PMID:24356524

  15. Accuracy of Nurse-Performed Lung Ultrasound in Patients With Acute Dyspnea

    PubMed Central

    Mumoli, Nicola; Vitale, Josè; Giorgi-Pierfranceschi, Matteo; Cresci, Alessandra; Cei, Marco; Basile, Valentina; Brondi, Barbara; Russo, Elisa; Giuntini, Lucia; Masi, Lorenzo; Cocciolo, Massimo; Dentali, Francesco

    2016-01-01

    Abstract In clinical practice lung ultrasound (LUS) is becoming an easy and reliable noninvasive tool for the evaluation of dyspnea. The aim of this study was to assess the accuracy of nurse-performed LUS, in particular, in the diagnosis of acute cardiogenic pulmonary congestion. We prospectively evaluated all the consecutive patients admitted for dyspnea in our Medicine Department between April and July 2014. At admission, serum brain natriuretic peptide (BNP) levels and LUS was performed by trained nurses blinded to clinical and laboratory data. The accuracy of nurse-performed LUS alone and combined with BNP for the diagnosis of acute cardiogenic dyspnea was calculated. Two hundred twenty-six patients (41.6% men, mean age 78.7 ± 12.7 years) were included in the study. Nurse-performed LUS alone had a sensitivity of 95.3% (95% CI: 92.6–98.1%), a specificity of 88.2% (95% CI: 84.0–92.4%), a positive predictive value of 87.9% (95% CI: 83.7–92.2%) and a negative predictive value of 95.5% (95% CI: 92.7–98.2%). The combination of nurse-performed LUS with BNP level (cut-off 400 pg/mL) resulted in a higher sensitivity (98.9%, 95% CI: 97.4–100%), negative predictive value (98.8%, 95% CI: 97.2–100%), and corresponding negative likelihood ratio (0.01, 95% CI: 0.0, 0.07). Nurse-performed LUS had a good accuracy in the diagnosis of acute cardiogenic dyspnea. Use of this technique in combination with BNP seems to be useful in ruling out cardiogenic dyspnea. Other studies are warranted to confirm our preliminary findings and to establish the role of this tool in other settings. PMID:26945396

  16. Accuracy of Nurse-Performed Lung Ultrasound in Patients With Acute Dyspnea: A Prospective Observational Study.

    PubMed

    Mumoli, Nicola; Vitale, Josè; Giorgi-Pierfranceschi, Matteo; Cresci, Alessandra; Cei, Marco; Basile, Valentina; Brondi, Barbara; Russo, Elisa; Giuntini, Lucia; Masi, Lorenzo; Cocciolo, Massimo; Dentali, Francesco

    2016-03-01

    In clinical practice lung ultrasound (LUS) is becoming an easy and reliable noninvasive tool for the evaluation of dyspnea. The aim of this study was to assess the accuracy of nurse-performed LUS, in particular, in the diagnosis of acute cardiogenic pulmonary congestion. We prospectively evaluated all the consecutive patients admitted for dyspnea in our Medicine Department between April and July 2014. At admission, serum brain natriuretic peptide (BNP) levels and LUS was performed by trained nurses blinded to clinical and laboratory data. The accuracy of nurse-performed LUS alone and combined with BNP for the diagnosis of acute cardiogenic dyspnea was calculated. Two hundred twenty-six patients (41.6% men, mean age 78.7 ± 12.7 years) were included in the study. Nurse-performed LUS alone had a sensitivity of 95.3% (95% CI: 92.6-98.1%), a specificity of 88.2% (95% CI: 84.0-92.4%), a positive predictive value of 87.9% (95% CI: 83.7-92.2%) and a negative predictive value of 95.5% (95% CI: 92.7-98.2%). The combination of nurse-performed LUS with BNP level (cut-off 400 pg/mL) resulted in a higher sensitivity (98.9%, 95% CI: 97.4-100%), negative predictive value (98.8%, 95% CI: 97.2-100%), and corresponding negative likelihood ratio (0.01, 95% CI: 0.0, 0.07). Nurse-performed LUS had a good accuracy in the diagnosis of acute cardiogenic dyspnea. Use of this technique in combination with BNP seems to be useful in ruling out cardiogenic dyspnea. Other studies are warranted to confirm our preliminary findings and to establish the role of this tool in other settings. PMID:26945396

  17. Lung Volume Reduction Surgery and Pulmonary Rehabilitation Improve Exercise Capacity and Reduce Dyspnea During Functional Activities in People with Emphysema

    PubMed Central

    2009-01-01

    Purpose: The purpose of this study was to examine the therapeutic effects of lung volume reduction surgery (LVRS) and pulmonary rehabilitation on levels of dyspnea during functional activities in patients with diffuse emphysema. Methods: Fifteen subjects who had undergone LVRS participated in this study. A visual analog scale (VAS) Activity Dyspnea Scales (VADS) measurement tool developed for this study was determined reliable in 10 subjects. The VADS was used to assess changes in dyspnea with functional activity in 10 subjects prior to and following the interventions of LVRS and pulmonary rehabilitation. Results: Results of this study indicate that LVRS followed by pulmonary rehabilitation significantly reduces levels of dyspnea during functional activities. Conclusion: The VADS developed for this study is a valid and reliable method of assessing changes in levels of dyspnea during functional activities in the LVRS population. PMID:20467532

  18. COMPARISON OF METHODS FOR EVALUATION OF EXPERIMENTALLY INDUCED EMPHYSEMA

    EPA Science Inventory

    Four methods to quantify induced emphysema, in a manner economically applicable to large numbers of animals, are compared by correlation analyses. Lung tissue used was from rats pretreated intratracheally with elastase or saline prior to exposure to air or (NH4)2SO4 or NH4NO3 aer...

  19. Induced thermoluminescence study of experimentally shock-loaded oligoclase

    NASA Technical Reports Server (NTRS)

    Ivliev, A. I.; Kashkarov, L. L.; Badjukov, D. D.

    1993-01-01

    Artificially induced thermoluminescence (TL) in oligoclase samples which were shock-loaded up to 27 GPa was measured. The essential increase of the TL sensitivity in relation to the total gamma-ray irradiation dose was observed only in samples at the 27 GPa pressure. This result can be explained by the initiation of additional radiation damages in the shocked oligoclace crystal lattice.

  20. Experimentally induced muscle pain induces hypoalgesia in heterotopic deep tissues, but not in homotopic deep tissues.

    PubMed

    Graven-Nielsen, T; Babenko, V; Svensson, P; Arendt-Nielsen, L

    1998-03-23

    The ability of muscle pain to generate somatosensory sensibility changes is controversial. Thus, in the present study, tonic infusion of hypertonic saline (5%, 7.1 ml administered over 15 min) into the tibialis anterior (TA) muscle was used as an experimental model to induce local and referred pain. The sensibility to high-intensity pressure stimuli applied to the local pain area, referred pain area and an arm was assessed in 14 healthy volunteers. Infusion of isotonic (0.9%) saline into the other leg served as control. The subject continuously scored the pain intensity on an electronic visual analogue scale (VAS). Pressure pain threshold (PPT) was determined on the TA muscle (2 cm and 10 cm from the infusion site), at the frontal aspect of the ankle (area of referred pain) and on the arm. To minimise the skin component of the PPT, the skin covering the assessment sites was anaesthetised with an anaesthetic creme. The PPTs were obtained before and after cutaneous analgesia, 1 min and 10 min after infusion start and 10 min after the pain had disappeared. Infusion of hypertonic saline caused significantly (P<0. 05) higher VAS scores than infusion of isotonic saline. A significant (P<0.04) increase of the PPT (i.e., decreased sensibility) was found at the ankle and on the arm during muscle pain compared to the control condition. No significant differences in PPTs on the TA muscle were found during saline-induced muscle pain compared to the infusion of isotonic saline. The decrease in deep sensibility at the heterotopic sites (referred pain area and arm), but not at homotopic sites (TA muscle), probably reflected the phenomenon of diffuse noxious inhibitory control (DNIC). The inhibitory mechanism during muscle pain was shown to be effective for the deep tissue sensibility in healthy subjects. Thus, a pathologically disturbed inhibitory mechanism may result in widespread deep hyperalgesia in muscle pain patients. PMID:9518613

  1. Clinical and experimental experiences of graft-induced dyskinesia.

    PubMed

    Lane, Emma L

    2011-01-01

    Clinical trials evaluating transplantation of fetal tissue for the treatment of Parkinson's disease identified the unexpected side effect of abnormal movements in the 'off'l-DOPA state. Termed graft-induced dyskinesia (GID), various hypotheses have been put forward as to their cause but unfortunately the significant differences in clinical trial protocols and lack of a truly representative animal model has hindered the search for a conclusive basis for their appearance. Likely causative factors have been identified through careful examination of patient data and the use of amphetamine-induced dyskinesia in a rodent model of Parkinson's disease. New trials being planned in Europe hope to avoid GID, whilst maximizing on the functional benefit that can be afforded by this treatment approach but questions still remain as to the underlying mechanism. PMID:21907087

  2. Experimental Feedback Control of Flow Induced Cavity Tones

    NASA Technical Reports Server (NTRS)

    Cabell, Randolph H.; Kegerise, Michael A.; Cox, David E.; Gibbs, Gary P.

    2002-01-01

    An experimental study of the application of discrete-time, linear quadratic control design methods to the cavity tone problem is described. State space models of the dynamics from a synthetic jet actuator at the leading edge of the cavity to two pressure sensors in the cavity were computed from experimental data. Variations in model order, control order, control bandwidth, and properties of a Kalman state estimator were studied. Feedback control reduced the levels of multiple cavity tones at Mach 0.275, 0.35, and 0.45. Closed loop performance was often limited by excitation of sidebands of cavity tones, and creation of new tones in the spectrum. State space models were useful for explaining some of these limitations, but were not able to account for non-linear dynamics, such as interactions between tones at different frequencies.

  3. Comparison of methods for evaluation of experimentally induced emphysema

    SciTech Connect

    Busch, R.H.; Buschbom, R.L.; Smith, L.G.

    1984-04-01

    Four methods to quantify induced emphysema, in a manner economically applicable to large numbers of animals, are compared by correlation analyses. Lung tissue used was from rats pretreated intratracheally with elastase or saline prior to exposure to air or (NH/sub 4/)/sub 2/SO/sub 4/ or NH/sub 4/NO/sub 3/ aerosols. The most sensitive quantitative evaluation was from mean chord length (MCL) measurements on scanning electron micrographs (SEM). Four-corner and parallel-line grids provided similar results, and reducing sample size to one selected field per lobe yielded a high degree of reliability for MCL measurements. Alveolar-pore perimeter and area (also measured on SEM photographs) were increased by induced emphysema, but were not reliable indicators for degree of pulmonary involvement. Both subjective score (grading the degree of emphysema) and percentage-area-affected determinations indicated the presence of emphysema, but with less sensitivity than MCL measurements. However, these two subgross methods (performed with a dissecting microscope) provided valuable information on the distribution of pulmonary lesions; emphysema was induced in a nonuniform but consistent and progressive pattern in the two lobes of the lung studied. 23 studied.

  4. Experimental study of microwave-induced thermoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Jacobs, Ryan T.

    Microwave-Induced Thermoacoustic Imaging (TAI) is a noninvasive hybrid modality which improves contrast by using thermoelastic wave generation induced by microwave absorption. Ultrasonography is widely used in medical practice as a low-cost alternative and supplement to magnetic resonance imaging (MRI). Although ultrasonography has relatively high image resolution (depending on the ultrasonic wavelength at diagnostic frequencies), it suffers from low image contrast of soft tissues. In this work samples are irradiated with sub-microsecond electromagnetic pulses inducing acoustic waves in the sample that are then detected with an unfocused transducer. The advantage of this hybrid modality is the ability to take advantage of the microwave absorption coefficients which provide high contrast in tissue samples. This in combination with the superior spatial resolution of ultrasound waves is important to providing a low-cost alternative to MRI and early breast cancer detection methods. This work describes the implementation of a thermoacoustic experiment using a 5 kW peak power microwave source.

  5. Corilagin Attenuates Aerosol Bleomycin-Induced Experimental Lung Injury

    PubMed Central

    Wang, Zheng; Guo, Qiong-Ya; Zhang, Xiao-Ju; Li, Xiao; Li, Wen-Ting; Ma, Xi-Tao; Ma, Li-Jun

    2014-01-01

    Idiopathic pulmonary fibrosis (IPF) is a progressing lethal disease with few clinically effective therapies. Corilagin is a tannin derivative which shows anti-inflammatory and antifibrotics properties and is potentiated in treating IPF. Here, we investigated the effect of corilagin on lung injury following bleomycin exposure in an animal model of pulmonary fibrosis. Corilagin abrogated bleomycin-induced lung fibrosis as assessed by H&E; Masson’s trichrome staining and lung hydroxyproline content in lung tissue. Corilagin reduced the number of apoptotic lung cells and prevented lung epithelial cells from membrane breakdown, effluence of lamellar bodies and thickening of the respiratory membrane. Bleomycin exposure induced expression of MDA, IKKα, phosphorylated IKKα (p-IKKα), NF-κB P65, TNF-α and IL-1β, and reduced I-κB expression in mice lung tissue or in BALF. These changes were reversed by high-dose corilagin (100 mg/kg i.p) more dramatically than by low dose (10 mg/kg i.p). Last, corilagin inhibits TGF-β1 production and α-SMA expression in lung tissue samples. Taken together, these findings confirmed that corilagin attenuates bleomycin-induced epithelial injury and fibrosis via inactivation of oxidative stress, proinflammatory cytokine release and NF-κB and TGF-β1 signaling. Corilagin may serve as a promising therapeutic agent for pulmonary fibrosis. PMID:24886817

  6. Association of chest pain versus dyspnea as presenting symptom for coronary angiography with demographics, coronary anatomy, and 2-year mortality

    PubMed Central

    Paudel, Rajiv; Beridze, Natalia; Ahn, Chul; Sanaani, Abdallah; Agarwal, Pallak; Farell, Kim; Jain, Diwakar; Timmermans, Robert; Cooper, Howard A.; Panza, Julio A

    2016-01-01

    Introduction The association of chest pain versus dyspnea with demographics, coronary angiographic findings, and outcomes of patients undergoing coronary angiography is unknown. Material and methods We studied 1,053 patients who had coronary angiography to investigate the association of chest pain versus dyspnea with demographics, coronary angiographic findings, and outcomes. Results Of 1,053 patients, 654 (62%) had chest pain, 229 (22%) had dyspnea, and 117 (11%) had chest pain and dyspnea. Patients with dyspnea were older (p < 0.0001) and had higher serum creatinine (p = 0.0011), lower left ventricular ejection fraction (LVEF) (p < 0.0001), more cardiogenic shock (p = 0.0004), less obstructive coronary artery disease (CAD) (p < 0.0001), less percutaneous coronary intervention (p < 0.0001), and similar 2-year mortality. Stepwise Cox regression analysis showed no significant difference in mortality between chest pain and dyspnea. Significant risk factors for time to death were age (hazard ratio (HR) = 1.07, p < 0.0001), serum creatinine (HR = 1.5, p < 0.0001), body mass index (HR = 0.93, p = 0.005), and obstructive CAD graft (HR = 3.2, p = 0.011). Conclusions Patients undergoing coronary angiography presenting with dyspnea were older and had higher serum creatinine, lower LVEF, more frequent cardiogenic shock, less obstructive CAD, and less percutaneous coronary intervention compared to patients presenting with chest pain but similar 2-year mortality. PMID:27478454

  7. Dynamic hyperinflation and dyspnea during the 6-minute walk test in stable chronic obstructive pulmonary disease patients.

    PubMed

    Satake, Masahiro; Shioya, Takanobu; Uemura, Sachiko; Takahashi, Hitomi; Sugawara, Keiyu; Kasai, Chikage; Kiyokawa, Noritaka; Watanabe, Toru; Sato, Sayaka; Kawagoshi, Atsuyoshi

    2015-01-01

    The purpose of this study was to investigate the relationship between dynamic hyperinflation and dyspnea and to clarify the characteristics of dyspnea during the 6-minute walk test (6MWT) in chronic obstructive pulmonary disease patients. Twenty-three subjects with stable moderate chronic obstructive pulmonary disease (age 73.8±5.8 years, all male) took part in this study. During the 6MWT, ventilatory and gas exchange parameters were measured using a portable respiratory gas analysis system. Dyspnea and oxygen saturation were recorded at the end of every 2 minute period during the test. There was a significant decrease in inspiratory capacity during the 6MWT. This suggested that dynamic hyperinflation had occurred. Dyspnea showed a significant linear increase, and there was a significant negative correlation with inspiratory capacity. It was suggested that one of the reasons that dyspnea developed during the 6MWT was the dynamic hyperinflation. Even though the tidal volume increased little after 2 minutes, dyspnea increased linearly to the end of the 6MWT. These results suggest that the mechanisms generating dyspnea during the 6MWT were the sense of respiratory effort at an early stage and then the mismatch between central motor command output and respiratory system movement. PMID:25632228

  8. 29-year-old man presenting with progressive dyspnea, oculocutaneous albinism, and epistaxis.

    PubMed

    Asefi, Golriz; Lahiji, Arta; Kamangar, Nader

    2015-06-01

    A 29-year-old man with a history of oculocutaneous albinism presented to the ED complaining of progressive dyspnea on exertion. One month prior to admission, the patient had begun to experience worsening dyspnea provoked by routine household activities. Additionally, he had developed a nonproductive cough, exacerbated by cold weather. He denied associated chest pain, hemoptysis, fever, chills, or night sweats. He denied any new exposures or sick contacts in the recent past. A review of systems was significant for a history of epistaxis and frequent bruising. Born in Honduras, he had immigrated to the United States approximately 10 years prior to his presentation to our facility. Furthermore, there was no family history of albinism, bleeding disorders, or pulmonary disease. PMID:26033137

  9. A 34-Year-Old Woman With Recurrent Right-Sided Chest Pain and Dyspnea.

    PubMed

    Albores, Jeffrey; Fishbein, Gregory; Bando, Joanne

    2015-11-01

    A 34-year-old woman presented with her third episode of acute-onset right-sided chest pain and dyspnea. She had two prior similar occurrences of right-sided sharp, pleuritic chest pain with radiation to the back and dyspnea. Chest radiographs during these presentations revealed a small apical right-sided pneumothorax that was managed conservatively with high-flow oxygen. All three presentations were associated with vigorous exercise and the first day of her menses. She denied cough, hemoptysis, fever, smoking history, airplane travel, scuba diving, or trauma during these presentations. The patient has been trying to conceive for the past year but has been unsuccessful because of uterine fibroids but no history of endometriosis. PMID:26527442

  10. Dyspnea-related anxiety: The Dutch version of the Breathlessness Beliefs Questionnaire.

    PubMed

    De Peuter, Steven; Janssens, Thomas; Van Diest, Ilse; Stans, Linda; Troosters, Thierry; Decramer, Marc; Van den Bergh, Omer; Vlaeyen, Johan W S

    2011-01-01

    Dyspnea-related anxiety may lead to reduced quality of life and functional disability through fearful avoidance of dyspnea-evoking activity. We describe the validation of a generic - diagnosis-independent - instrument assessing dyspnea-related anxiety. A total of 187 patients with respiratory diseases completed the Breathlessness Beliefs Questionnaire (BBQ), a 17-item questionnaire adapted from the Tampa Scale for Kinesiophobia (TSK), a measure of how harmful pain patients think painful movement is and to what extent they think activity should be avoided. Measures of negative and positive affectivity (PANAS), anxiety and depression (HADS), functional status (PFSDQ), and health-related quality of life (CRDQ) were also completed. Principal component analysis and item-total correlations suggested a reliable (reduced) 11-item BBQ (Cronbach's alpha = .85) with two factors converging with the TSK factors: a 'somatic focus' factor assessing the harmfulness of dyspnea and the underlying pathology and an 'activity avoidance' factor assessing beliefs that activity should be avoided. Correlational analyses support the construct validity of the BBQ: higher scores on the BBQ are associated with reduced health-related quality of life and functional status. Associations between 'somatic focus' and negative affectivity and anxiety and between 'activity avoidance' and positive affectivity and depression further supported the validity of the BBQ and its subscales. The BBQ is a valid, short, and useful instrument to assess respiratory patients' beliefs about the harmfulness of their disease and physical activities. Further research is needed to document to what extent BBQ scores are related to daily life activities and symptoms. PMID:21172990

  11. Experimental Feedback Control of Flow Induced Cavity Tones

    NASA Technical Reports Server (NTRS)

    Cabell, Randolph H.; Kegerise, Michael A.; Cox, David E.; Gibbs, Gary P.

    2005-01-01

    Discrete-time, linear quadratic methods were used to design feedback controllers for reducing tones generated by flow over a cavity. The dynamics of a synthetic jet actuator mounted at the leading edge of the cavity as observed by two microphones in the cavity were modeled over a broad frequency range using state space models computed from experimental data. Variations in closed loop performance as a function of model order, control order, control bandwidth, and state estimator design were studied using a cavity in the Probe Calibration Tunnel at NASA Langley. The controller successfully reduced the levels of multiple cavity tones at the tested flow speeds of Mach 0.275, 0.35, and 0.45. In some cases, the closed loop results were limited by excitation of sidebands of the cavity tones, or the creation of new tones at frequencies away from the cavity tones. Nonetheless, the results validate the combination of optimal control and experimentally-generated state space models, and suggest this approach may be useful for other flow control problems. The models were not able to account for non-linear dynamics, such as interactions between tones at different frequencies.

  12. Experimental distinction of Autler-Townes splitting from electromagnetically induced transparency using coupled mechanical oscillators system

    PubMed Central

    Liu, Jingliang; Yang, Hujiang; Wang, Chuan; Xu, Kun; Xiao, Jinghua

    2016-01-01

    Here we experimentally demonstrated the electromagnetically induced transparency (EIT) and Autler-Townes splitting (ATS) effects in mechanical coupled pendulums. The analogue of EIT and ATS has been studied in mechanical systems and the intrinsic physics between these two phenomena are also been discussed. Exploiting the Akaike Information Criterion, we discern the ATS effect from EIT effect in our experimental results. PMID:26751738

  13. An Attempt to Reverse Performance Deficits Associated With Depression and Experimentally Induced Helplessness

    ERIC Educational Resources Information Center

    Kilpatrick-Tabak, Blair; Roth, Susan

    1978-01-01

    The learned helplessness model of depression predicts that any effective treatment for reactive depression should also reverse performance deficits associated with experimentally induced helplessness, and vice versa. This study tests that prediction with college students who were exposed to experimental manipulations designed to induce…

  14. Experimental distinction of Autler-Townes splitting from electromagnetically induced transparency using coupled mechanical oscillators system

    NASA Astrophysics Data System (ADS)

    Liu, Jingliang; Yang, Hujiang; Wang, Chuan; Xu, Kun; Xiao, Jinghua

    2016-01-01

    Here we experimentally demonstrated the electromagnetically induced transparency (EIT) and Autler-Townes splitting (ATS) effects in mechanical coupled pendulums. The analogue of EIT and ATS has been studied in mechanical systems and the intrinsic physics between these two phenomena are also been discussed. Exploiting the Akaike Information Criterion, we discern the ATS effect from EIT effect in our experimental results.

  15. Does expiratory muscle activity influence dynamic hyperinflation and exertional dyspnea in COPD?

    PubMed

    Laveneziana, Pierantonio; Webb, Katherine A; Wadell, Karin; Neder, J Alberto; O'Donnell, Denis E

    2014-08-01

    Increased expiratory muscle activity is common during exercise in patients with COPD but its role in modulating operating lung volumes and dyspnea during incremental cycle ergometry is currently unknown. We compared gastric (Pga) and esophageal (Pes) pressures, operating lung volumes and qualitative descriptors of dyspnea during exercise in 12 COPD patients and 12 age- and sex-matched healthy controls. Pes- and Pga-derived measures of expiratory muscle activity were significantly (p<0.05) greater in COPD than in health during exercise. End-expiratory lung volume (EELV) increased by 0.8L, independent of increased expiratory muscle activity in COPD. Dynamic function of the diaphragm was not different in health and COPD throughout exercise. In both groups, dyspnea descriptors alluding to increased work and inspiratory difficulty predominated whereas expiratory difficulty was rarely reported, even at the limits of tolerance. In conclusion, increased expiratory muscle activity did not mitigate the rise in EELV, the relatively early respiratory mechanical constraints or the attendant perceived inspiratory difficulty during exercise in COPD. PMID:24793133

  16. Effects of flunarizine on experimentally-induced convulsions in animals.

    PubMed

    Drago, F; Valerio, C; Clementi, G; Scapagnini, U

    1986-01-01

    D,L-allylglycine-induced seizures in rats were antagonized by flunarizine and other antiepileptic drugs. In this respect, the spectrum of flunarizine appears to be similar to that of diphenylhydantoin. A behavioral analysis of the effects of various drugs on amygdaloid kindled rats showed that flunarizine exerts anticonvulsive effects in this model with an ED50 of 42.8 mg/kg. Furthermore, flunarizine (1, 5, 25 and 50 mg/kg i.p.) reduced seizure parameters in rats injected with strychnine or pentetrazol. In this case, flunarizine reduced seizure intensity and increased the percentage of survival. In another study on genetically epileptic beagles, flunarizine significantly affected the REM and deep slow-wave sleep latencies. PMID:3609879

  17. Experimental Studies of Laser-Induced Breakdown in Transparent Dielectrics

    SciTech Connect

    Carr, C W

    2003-09-23

    The mechanisms by which transparent dielectrics damage when exposed to high power laser radiation has been of scientific and technological interest since the invention of the laser. In this work, a set of three experiments are presented which provide insight into the damage initiation mechanisms and the processes involved in laser-induced damage. Using an OPO (optical parametric oscillator) laser, we have measured the damage thresholds of deuterated potassium dihydrogen phosphate (DKDP) from the near ultraviolet into the visible. Distinct steps, whose width is of order K{sub b}T, are observed in the damage threshold at photon energies associated with the number of photons (3{yields}2 or 4{yields}3) needed to promote a ground state electron across the energy gap. The wavelength dependence of the damage threshold suggests that a primary mechanism for damage initiation in DKDP is a multi-photon process in which the order is reduced through excited defect state absorption. In-situ fluorescence microscopy, in conjunction with theoretical calculations by Liu et al., has been used to establish that hydrogen displacement defects are potentially responsible for the reduction in the multi-photon cross-section. During the damage process, the material absorbs energy from the laser pulse and produces an ionized region that gives rise to broadband emission. By performing a time-resolved investigation of this emission, we demonstrate both that it is blackbody in nature, and we provide the first direct measurement of the localized temperature during and following laser damage initiation for various optical materials. For excitation using nanosecond laser pulses, the plasma, when confined in the bulk, is in thermal equilibrium with the lattice. These results allow for a detailed characterization of temperature, pressure, and electron densities occurring during laser-induced damage.

  18. Experimental diet-induced atherosclerosis in Quaker parrots (Myiopsitta monachus).

    PubMed

    Beaufrère, H; Nevarez, J G; Wakamatsu, N; Clubb, S; Cray, C; Tully, T N

    2013-11-01

    Spontaneous atherosclerosis is common in psittaciformes, and clinical signs associated with flow-limiting stenosis are encountered in pet birds. Nevertheless, a psittacine model of atherosclerosis has not been developed for research investigations. Sixteen captive-bred Quaker parrots (Myiopsitta monachus) were used in this study. While 4 control birds were fed a maintenance diet, 12 other birds were fed an atherogenic diet composed of 1% cholesterol controlling for a calorie-to-protein ratio for periods ranging from 2 to 8 months. The birds were euthanized at the end of their respective food trial period. Histopathology, transmission electron microscopy, and cholesterol measurement were performed on the ascending aorta and brachiocephalic and pulmonary arteries. Plasma lipoproteins, cholesterol, and triglycerides were also measured on a monthly basis. Significant atherosclerotic lesions were induced within 2 months and advanced atherosclerotic lesions within 4 to 6 months. The advanced lesions were histologically similar to naturally occurring lesions identified in the same parrot species with a lipid core and a fibrous cap. Ultrastructurally, there were extracellular lipid, foam cell, and endothelial changes. Arterial cholesterol content increased linearly over time. Plasma cholesterol and low-density lipoprotein (LDL) significantly increased over time by an average of 5- and 15-fold, respectively, with a shift from high-density lipoprotein to LDL as the main plasma lipoprotein. Quaker parrots also exhibited high plasma cholesteryl ester transfer protein activity that increased, although not significantly, over time. This experiment demonstrates that in Quaker parrots fed 1% cholesterol, advanced atherosclerosis can be induced relatively quickly, and lesions resemble those found in other avian models and humans. PMID:23696447

  19. Hypolipidemic effect of gypenosides in experimentally induced hypercholesterolemic rats

    PubMed Central

    2013-01-01

    Background To investigate the anti-hyperlipidemic effect of gynosaponins (GPs) in hyperlipidemic rats induced by high lipid diet. Methods Animal model of hyperlipidemia was established by high-fat and high-cholesterol diet. Rats were randomly divided into 6 groups, except the normal and model groups, rats in GPs groups were daily administered intragastrically with GPs (50, 100, and 200 mg/kg), and rats in simvastatin group were daily administered intragastrically with simvastatin (10 mg/kg). It was measured that the contents of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), total cholesterol (TC), triglyceride (TG), high-density lipoprotein-cholesterol (HDL-C) and low-density lipoprotein-cholesterol (LDL-C) in the serum, TG and TC in the liver during this experiment, respectively. The left lobe of liver was observed by histopathological staining, and the immunohistochemical staining was used to observe the effects on the effect of GPs on liver functions. Results Compared with the model group, GPs groups could remarkably decrease the content of lipids, GSH-Px, SOD, CAT and MDA in the serum and TC and TG in the liver of the hyperlipidemic rats. The pathomorphological results of hepatic tissue showed that fatty degeneration and inflammatory reaction of GPs groups were lightened compared with the model group. Conclusions The results show that GPs has good effects on the treatment of hyperlipidemia induced by high lipid diet in rats. The possible anti-hyperlipidemia mechanism maybe those GPs can regulate the disorder of lipid metabolism as well as ameliorate hepatic function. PMID:24160562

  20. Histochemical changes in the testes of lead induced experimental rats.

    PubMed

    Chowdhury, A R; Rao, R V; Gautam, A K

    1986-01-01

    The experiments were performed on mature male rats divided in five groups, one control and four experimental in which the animals received 1 mg, 2 mg, 4 mg and 6 mg/kg body weight lead acetate intraperitoneally respectively, over a period of 30 days. ALA-D and lead was estimated in the blood by the use of atomic absorption spectrophotometer and ATP-ase, AMP-ase, Alk-ase were histochemically localized. Significant increase in blood and testis of lead levels along with decrease of ALA-D levels were observed. Changes in the testicular tissue were encountered. Other details concerned with the damage of the testicular tissue are discussed. PMID:3030829

  1. Dietary oregano essential oil alleviates experimentally induced coccidiosis in broilers.

    PubMed

    Mohiti-Asli, M; Ghanaatparast-Rashti, M

    2015-06-15

    An experiment was conducted to determine the effects of oregano essential oil on growth performance and coccidiosis prevention in mild challenged broilers. A total of 250 1-d-old chicks were used in a completely randomized design with 5 treatments and 5 replicates with 10 birds in each replication. Experimental treatments included: (1) negative control (NC; unchallenged), (2) positive control (PC; challenged with sporulated oocysts of Eimeria), (3) PC fed 200 ppm Diclazuril in diet, (4) PC fed 300 ppm oregano oil in diet, and (5) PC fed 500 ppm oregano oil in diet. At 22 d of age, all the experimental groups except for NC were challenged with 50-fold dose of Livacox T as a trivalent live attenuated coccidiosis vaccine. On d 28, two birds were slaughtered and intestinal coccidiosis lesions were scored 0-4. Moreover, dropping was scored in the scale of 0-3, and oocysts per gram feces (OPG) were measured. Oregano oil at either supplementation rate increased body weight gain (P=0.039) and improved feed conversion ratio (P=0.010) from d 22 to 28, when compared with PC group. Using 500 ppm oregano oil in challenged broilers diet increased European efficiency factor than PC group (P=0.020). Moreover, challenged broilers fed 500 ppm oregano oil or Diclazuril in diets displayed lower coccidiosis lesions scores in upper (P=0.003) and middle (P=0.018) regions of intestine than PC group, with the effect being similar to unchallenged birds. In general, challenged birds fed 500 ppm oregano oil or Diclazuril in diets had lower OPG (P=0.001), dropping scores (P=0.001), litter scores (P=0.001), and pH of litter (P=0.001) than PC group. It could be concluded that supplementation of oregano oil at the dose of 500 ppm in diet may have beneficial effect on prevention of coccidiosis in broilers. PMID:25864115

  2. Experimental treatment of antipsychotic-induced movement disorders

    PubMed Central

    Shireen, Erum

    2016-01-01

    Antipsychotic drugs are extensively prescribed for the treatment of schizophrenia and other related psychiatric disorders. These drugs produced their action by blocking dopamine (DA) receptors, and these receptors are widely present throughout the brain. Therefore, extended antipsychotic use also leads to severe extrapyramidal side effects. The short-term effects include parkinsonism and the later appearing tardive dyskinesia. Currently available treatments for these disorders are mostly symptomatic and insufficient, and are often linked with a number of detrimental side effects. Antipsychotic-drug-induced tardive dyskinesia prompted researchers to explore novel drugs with fewer undesirable extrapyramidal side effects. Preclinical studies suggest a role of 5-hydroxytryptamine (serotonin)-1A and 2A/2C receptors in the modulation of dopaminergic neurotransmission and motivating a search for better therapeutic strategies for schizophrenia and related disorders. In addition, adjunctive treatment with antioxidants such as vitamin E, red rice bran oil, and curcumin in the early phases of illness may prevent additional oxidative injury, and thus improve and prevent further possible worsening of related neurological and behavioral deficits in schizophrenia. This review explains the role of serotonergic receptors and oxidative stress, with the aim of providing principles for prospect development of compounds to improve therapeutic effects of antischizophrenic drugs. PMID:27540314

  3. Chemically induced skin carcinogenesis: Updates in experimental models (Review).

    PubMed

    Neagu, Monica; Caruntu, Constantin; Constantin, Carolina; Boda, Daniel; Zurac, Sabina; Spandidos, Demetrios A; Tsatsakis, Aristidis M

    2016-05-01

    Skin cancer is one of the most common malignancies affecting humans worldwide, and its incidence is rapidly increasing. The study of skin carcinogenesis is of major interest for both scientific research and clinical practice and the use of in vivo systems may facilitate the investigation of early alterations in the skin and of the mechanisms involved, and may also lead to the development of novel therapeutic strategies for skin cancer. This review outlines several aspects regarding the skin toxicity testing domain in mouse models of chemically induced skin carcinogenesis. There are important strain differences in view of the histological type, development and clinical evolution of the skin tumor, differences reported decades ago and confirmed by our hands‑on experience. Using mouse models in preclinical testing is important due to the fact that, at the molecular level, common mechanisms with human cutaneous tumorigenesis are depicted. These animal models resemble human skin cancer development, in that genetic changes caused by carcinogens and pro‑inflammatory cytokines, and simultaneous inflammation sustained by pro‑inflammatory cytokines and chemokines favor tumor progression. Drugs and environmental conditions can be tested using these animal models. keeping in mind the differences between human and rodent skin physiology. PMID:26986013

  4. Experimental treatment of antipsychotic-induced movement disorders.

    PubMed

    Shireen, Erum

    2016-01-01

    Antipsychotic drugs are extensively prescribed for the treatment of schizophrenia and other related psychiatric disorders. These drugs produced their action by blocking dopamine (DA) receptors, and these receptors are widely present throughout the brain. Therefore, extended antipsychotic use also leads to severe extrapyramidal side effects. The short-term effects include parkinsonism and the later appearing tardive dyskinesia. Currently available treatments for these disorders are mostly symptomatic and insufficient, and are often linked with a number of detrimental side effects. Antipsychotic-drug-induced tardive dyskinesia prompted researchers to explore novel drugs with fewer undesirable extrapyramidal side effects. Preclinical studies suggest a role of 5-hydroxytryptamine (serotonin)-1A and 2A/2C receptors in the modulation of dopaminergic neurotransmission and motivating a search for better therapeutic strategies for schizophrenia and related disorders. In addition, adjunctive treatment with antioxidants such as vitamin E, red rice bran oil, and curcumin in the early phases of illness may prevent additional oxidative injury, and thus improve and prevent further possible worsening of related neurological and behavioral deficits in schizophrenia. This review explains the role of serotonergic receptors and oxidative stress, with the aim of providing principles for prospect development of compounds to improve therapeutic effects of antischizophrenic drugs. PMID:27540314

  5. Experimentally induced metamorphosis in axolotls reduces regenerative rate and fidelity

    PubMed Central

    Stier, Adrian C.; Michonneau, François; Smith, Matthew D.; Pasch, Bret; Maden, Malcolm

    2014-01-01

    Abstract While most tetrapods are unable to regenerate severed body parts, amphibians display a remarkable ability to regenerate an array of structures. Frogs can regenerate appendages as larva, but they lose this ability around metamorphosis. In contrast, salamanders regenerate appendages as larva, juveniles, and adults. However, the extent to which fundamental traits (e.g., metamorphosis, body size, aging, etc.) restrict regenerative ability remains contentious. Here we utilize the ability of normally paedomorphic adult axolotls (Ambystoma mexicanum) to undergo induced metamorphosis by thyroxine exposure to test how metamorphosis and body size affects regeneration in age‐matched paedomorphic and metamorphic individuals. We show that body size does not affect regeneration in adult axolotls, but metamorphosis causes a twofold reduction in regeneration rate, and lead to carpal and digit malformations. Furthermore, we find evidence that metamorphic blastemal cells may take longer to traverse the cell cycle and display a lower proliferative rate. This study identifies the axolotl as a powerful system to study how metamorphosis restricts regeneration independently of developmental stage, body size, and age; and more broadly how metamorphosis affects tissue‐specific changes.

  6. Flagella-induced immunity against experimental cholera in adult rabbits.

    PubMed Central

    Yancey, R J; Willis, D L; Berry, L J

    1979-01-01

    The adult rabbit ligated ileal loop model was used to evaluate the prophylactic potential of a crude flagellar (CF) vaccine produced from the classical. Inaba strain CA401. A greater than 1,000-fold increase in the challenge inoculum was required to induce an intestinal fluid response in actively immunized adult rabbits equivalent to that produced in unimmunized animals. Similar protection was afforded against challenge with classical and El Tor biotypes of both Inaba and Ogawa serotypes. Highly virulent 35S-labeled vibrios were inhibited in their ability to associated with the intestinal mucosa of CF-immunized rabbits. The protection conferred by CF immunization was found to be superior to that of a commercial bivalent vaccine and also to that of glutaraldehyde-treated cholera toxoid. The critical immunogenic component of CF appears to be a flagella-derived protein. The immunogenicity of CF was destroyed by heat treatment, and absorption of CF-immune serum with aflagellated mutant vibrios did not diminish its ability to confer a high level of passive protection. The intestinal protection of CF-immunized rabbits was completely reversed by the introduction of both goat anti-rabbit immunoglobulins A and G, but by neither alone. PMID:478635

  7. Chemically induced skin carcinogenesis: Updates in experimental models (Review)

    PubMed Central

    NEAGU, MONICA; CARUNTU, CONSTANTIN; CONSTANTIN, CAROLINA; BODA, DANIEL; ZURAC, SABINA; SPANDIDOS, DEMETRIOS A.; TSATSAKIS, ARISTIDIS M.

    2016-01-01

    Skin cancer is one of the most common malignancies affecting humans worldwide, and its incidence is rapidly increasing. The study of skin carcinogenesis is of major interest for both scientific research and clinical practice and the use of in vivo systems may facilitate the investigation of early alterations in the skin and of the mechanisms involved, and may also lead to the development of novel therapeutic strategies for skin cancer. This review outlines several aspects regarding the skin toxicity testing domain in mouse models of chemically induced skin carcinogenesis. There are important strain differences in view of the histological type, development and clinical evolution of the skin tumor, differences reported decades ago and confirmed by our hands-on experience. Using mouse models in preclinical testing is important due to the fact that, at the molecular level, common mechanisms with human cutaneous tumorigenesis are depicted. These animal models resemble human skin cancer development, in that genetic changes caused by carcinogens and pro-inflammatory cytokines, and simultaneous inflammation sustained by pro-inflammatory cytokines and chemokines favor tumor progression. Drugs and environmental conditions can be tested using these animal models. keeping in mind the differences between human and rodent skin physiology. PMID:26986013

  8. Epithelial impedance analysis in experimentally induced colon cancer.

    PubMed Central

    Davies, R J; Joseph, R; Kaplan, D; Juncosa, R D; Pempinello, C; Asbun, H; Sedwitz, M M

    1987-01-01

    Epithelial impedance analysis was used to measure the alterations in resistance of the large bowel in a murine model of large bowel cancer. The technique was able to resolve the epithelial resistance from the total resistance of the bowel wall. A progressive decrease in resistance of the bowel epithelium occurs during carcinogenesis induced with dimethyhydrazine. About a 21% decrease in epithelial resistance from 22.0 +/- 1.3 omega.cm-2 to 17.5 +/- 1.1 omega cm-2 (p less than 0.025) was observed after 20 wk of carcinogen administration. The sensitivity of the technique in detecting altered epithelial resistance in premalignant bowel mucosa was improved by examining the impedance profile in a sodium-free Ringer's solution where the epithelium of control colons had a resistance of 24.4 +/- 1.8 omega.cm-2 compared with 19.0 +/- 1.1 omega.cm-2 (p less than 0.02) in colons from animals treated for only 4 wk with the carcinogen. Epithelial impedance analysis would seem to be a sensitive technique capable of identifying changes in the electrical properties or the large bowel early in disease states. PMID:3427187

  9. Experimentally induced photosensitization in cattle with Cooperia pedunculata.

    PubMed

    Casteel, S W; Rowe, L D; Bailey, E M; Fiske, R A; Bridges, C W

    1988-04-01

    Photosensitization was induced in 2 Charolais heifers following administration of a mixture of air-dried, ground, green (75%) and dead (25%) leaves of the south Texas forb, Cooperia pedunculata, and subsequent exposure to sunlight. Plant material used in this study was collected from a pasture where natural cases of primary bovine photosensitization were occurring. Signs of photosensitization were observed in one heifer after 2 doses of plant material--10 g/kg on day 1 and 5 g/kg on day 2. Continued administration of plant material at 5 g/kg/d on days 3, 4, 7, 8, and 9 resulted in severe signs and lesions of photosensitization and death on day 23. A second heifer developed signs of mild photosensitization following administration of plant material at 1.7 g/kg/d for 4 days. This heifer recovered by day 18. Clinical and pathologic findings of this trial were consistent with the primary form of photosensitization observed in natural cases seen in cattle of south Texas exposed to this plant. PMID:3381477

  10. Experimental Investigation of Cavitation Induced Feedline Instability from an Orifice

    NASA Technical Reports Server (NTRS)

    Hitt, Matthew A.; Lineberry, David M.; Ahuja, Vineet; Frederick, Robert A,

    2012-01-01

    This paper details the results of an experimental investigation into the cavitation instabilities created by a circular orifice conducted at the University of Alabama in Huntsville Propulsion Research Center. This experiment was conducted in concert with a computational simulation to serve as a reference point for the simulation. Testing was conducted using liquid nitrogen as a cryogenic propellant simulant. A 1.06 cm diameter thin orifice with a rounded inlet was tested in an approximately 1.25 kg/s flow with inlet pressures ranging from 504.1 kPa to 829.3 kPa. Pressure fluctuations generated by the orifice were measured using a high frequency pressure sensor located 0.64 tube diameters downstream of the orifice. Fast Fourier Transforms were performed on the high frequency data to determine the instability frequency. Shedding resulted in a primary frequency with a cavitation related subharmonic frequency. For this experiment, the cavitation instability ranged from 153 Hz to 275 Hz. Additionally, the strength of the cavitation occur red as a function of cavitation number. At lower cavitation numbers, the strength of the cavitation instability ranged from 2.4 % to 7 % of the inlet pressure. However, at higher cavitation numbers, the strength of the cavitation instability ranged from 0.6 % to 1 % of the inlet pressure.

  11. Toxin-Induced Experimental Models of Learning and Memory Impairment.

    PubMed

    More, Sandeep Vasant; Kumar, Hemant; Cho, Duk-Yeon; Yun, Yo-Sep; Choi, Dong-Kug

    2016-01-01

    Animal models for learning and memory have significantly contributed to novel strategies for drug development and hence are an imperative part in the assessment of therapeutics. Learning and memory involve different stages including acquisition, consolidation, and retrieval and each stage can be characterized using specific toxin. Recent studies have postulated the molecular basis of these processes and have also demonstrated many signaling molecules that are involved in several stages of memory. Most insights into learning and memory impairment and to develop a novel compound stems from the investigations performed in experimental models, especially those produced by neurotoxins models. Several toxins have been utilized based on their mechanism of action for learning and memory impairment such as scopolamine, streptozotocin, quinolinic acid, and domoic acid. Further, some toxins like 6-hydroxy dopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and amyloid-β are known to cause specific learning and memory impairment which imitate the disease pathology of Parkinson's disease dementia and Alzheimer's disease dementia. Apart from these toxins, several other toxins come under a miscellaneous category like an environmental pollutant, snake venoms, botulinum, and lipopolysaccharide. This review will focus on the various classes of neurotoxin models for learning and memory impairment with their specific mechanism of action that could assist the process of drug discovery and development for dementia and cognitive disorders. PMID:27598124

  12. Experimental particle acceleration by water evaporation induced by shock waves

    NASA Astrophysics Data System (ADS)

    Scolamacchia, T.; Alatorre Ibarguengoitia, M.; Scheu, B.; Dingwell, D. B.; Cimarelli, C.

    2010-12-01

    Shock waves are commonly generated during volcanic eruptions. They induce sudden changes in pressure and temperature causing phase changes. Nevertheless, their effects on flowfield properties are not well understood. Here we investigate the role of gas expansion generated by shock wave propagation in the acceleration of ash particles. We used a shock tube facility consisting of a high-pressure (HP) steel autoclave (450 mm long, 28 mm in internal diameter), pressurized with Ar gas, and a low-pressure tank at atmospheric conditions (LP). A copper diaphragm separated the HP autoclave from a 180 mm tube (PVC or acrylic glass) at ambient P, with the same internal diameter of the HP reservoir. Around the tube, a 30 cm-high acrylic glass cylinder, with the same section of the LP tank (40 cm), allowed the observation of the processes occurring downstream from the nozzle throat, and was large enough to act as an unconfined volume in which the initial diffracting shock and gas jet expand. All experiments were performed at Pres/Pamb ratios of 150:1. Two ambient conditions were used: dry air and air saturated with steam. Carbon fibers and glass spheres in a size range between 150 and 210 μm, were placed on a metal wire at the exit of the PVC tube. The sudden decompression of the Ar gas, due to the failure of the diaphragm, generated an initial air shock wave. A high-speed camera recorded the processes between the first 100 μsec and several ms after the diaphragm failure at frame rates ranging between 30,000 and 50,000 fps. In the experiments with ambient air saturated with steam, the high-speed camera allowed to visualize the condensation front associated with the initial air shock; a maximum velocity of 788 m/s was recorded, which decreases to 524 m/s at distance of 0.5 ±0.2 cm, 1.1 ms after the diaphragm rupture. The condensation front preceded the Ar jet front exhausting from the reservoir, by 0.2-0.5 ms. In all experiments particles velocities following the initial

  13. Experimental investigation of the flow induced by artificial cilia.

    PubMed

    Hussong, J; Schorr, N; Belardi, J; Prucker, O; Rühe, J; Westerweel, J

    2011-06-21

    The fluid transport produced by rectangular shaped, magnetically actuated artificial cilia of 70 μm length and 20 μm width was determined by means of phase-locked Micro Particle Image Velocimetry (μPIV) measurements in a closed microfluidic chamber. The phase-averaged flow produced by the artificial cilia reached up to 130 μm s(-1) with an actuation cycle frequency of 10 Hz. Analysis of the measured flow data indicate that the present system is capable of achieving volume flow rates of V[combining dot above](cilia) = 14 ± 4 μl min(-1) in a micro channel of 0.5 × 5 mm(2) cross-sectional area when no back pressure is built up. This corresponds to an effective pressure gradient of 6 ± 1 Pa m(-1), which equals a pressure difference of 0.6 ± 0.1 mPa over a distance of 100 μm between two rows of cilia. These results were derived analytically from the measured velocity profile by treating the cilia as a thin boundary layer. While the cilia produce phase-averaged velocities of the order of O(10(2)μm s(-1)), time-resolved measurements showed that the flow field reverses two times during one actuation cycle inducing instantaneous velocities of up to approximately 2 mm s(-1). This shows that the flow field is dominated by fluid oscillations and flow rates are expected to increase if the beating motion of the cilia is further improved. PMID:21614349

  14. Predictions of Experimentally Observed Stochastic Ground Vibrations Induced by Blasting

    PubMed Central

    Kostić, Srđan; Perc, Matjaž; Vasović, Nebojša; Trajković, Slobodan

    2013-01-01

    In the present paper, we investigate the blast induced ground motion recorded at the limestone quarry “Suva Vrela” near Kosjerić, which is located in the western part of Serbia. We examine the recorded signals by means of surrogate data methods and a determinism test, in order to determine whether the recorded ground velocity is stochastic or deterministic in nature. Longitudinal, transversal and the vertical ground motion component are analyzed at three monitoring points that are located at different distances from the blasting source. The analysis reveals that the recordings belong to a class of stationary linear stochastic processes with Gaussian inputs, which could be distorted by a monotonic, instantaneous, time-independent nonlinear function. Low determinism factors obtained with the determinism test further confirm the stochastic nature of the recordings. Guided by the outcome of time series analysis, we propose an improved prediction model for the peak particle velocity based on a neural network. We show that, while conventional predictors fail to provide acceptable prediction accuracy, the neural network model with four main blast parameters as input, namely total charge, maximum charge per delay, distance from the blasting source to the measuring point, and hole depth, delivers significantly more accurate predictions that may be applicable on site. We also perform a sensitivity analysis, which reveals that the distance from the blasting source has the strongest influence on the final value of the peak particle velocity. This is in full agreement with previous observations and theory, thus additionally validating our methodology and main conclusions. PMID:24358140

  15. Generation of hydroxyl radicals during ascites experimentally induced in broilers.

    PubMed

    Arab, H A; Jamshidi, R; Rassouli, A; Shams, G; Hassanzadeh, M H

    2006-04-01

    Increased metabolic rates, pulmonary hypertension and cardiac dysfunction are the most important features of the ascites syndrome in broiler chickens. However, the mechanism of cell injury causing the pathogenesis of the syndrome is not clearly understood. Our study aimed to examine the generation of hydroxyl radicals (OH*) in broiler chickens experiencing ascites. The hundred and fifty 1-d-old chickens were purchased from a local hatchery and reared in an open poultry house for 46 d. They were divided at random into three groups and ascites was induced in two groups by exposing them to low temperature or administration of triiodothyronine (T(3)). The third group served as control and was reared normally. Haematological, biochemical and pathological tests were used to determine the incidence of ascites: including total red blood cell (RBC), packed cell volume (PCV), release of alanine transaminase (ALT) and aspartate transaminase (AST) and ratio of right ventricular weight to total ventricular weight (RV/TV). A salicylate hydroxylation method was used to examine the generation of hydroxyl radicals (OH*) in treated groups. TWo hydroxylated salicylic acid metabolites, 2,3- and 2,5-dihydroxy benzoic acid (2,3- and 2,5-DHBA), were measured by HPLC to detect the generation of OH*. An ascites syndrome was observed in T(3) and low-temperature treated groups, as shown by necropsy changes and increases in f RBC, PCV, ALT, AST and the ratio of RV/TV. Concentrations of 2,3- and 2,5-DHBA were increased in groups experiencing ascites compared to control group. It is suggested that reactive oxygen species that is OH* ions, may be involved in the pathogenesis of the ascites syndrome in broiler chickens. PMID:16641033

  16. Immune Cells and Molecular Networks in Experimentally Induced Pulpitis.

    PubMed

    Renard, E; Gaudin, A; Bienvenu, G; Amiaud, J; Farges, J C; Cuturi, M C; Moreau, A; Alliot-Licht, B

    2016-02-01

    Dental pulp is a dynamic tissue able to resist external irritation during tooth decay by using immunocompetent cells involved in innate and adaptive responses. To better understand the immune response of pulp toward gram-negative bacteria, we analyzed biological mediators and immunocompetent cells in rat incisor pulp experimentally inflamed by either lipopolysaccharide (LPS) or saline solution (phosphate-buffered saline [PBS]). Untreated teeth were used as control. Expression of pro- and anti-inflammatory cytokines, chemokine ligands, growth factors, and enzymes were evaluated at the transcript level, and the recruitment of the different leukocytes in pulp was measured by fluorescence-activated cell-sorting analysis after 3 h, 9 h, and 3 d post-PBS or post-LPS treatment. After 3 d, injured rat incisors showed pulp wound healing and production of reparative dentin in both LPS and PBS conditions, testifying to the reversible pulpitis status of this model. IL6, IL1-β, TNF-α, CCL2, CXCL1, CXCL2, MMP9, and iNOS gene expression were significantly upregulated after 3 h of LPS stimulation as compared with PBS. The immunoregulatory cytokine IL10 was also upregulated after 3 h, suggesting that LPS stimulates not only inflammation but also immunoregulation. Fluorescence-activated cell-sorting analysis revealed a significant, rapid, and transient increase in leukocyte levels 9 h after PBS and LPS stimulation. The quantity of dendritic cells was significantly upregulated with LPS versus PBS. Interestingly, we identified a myeloid-derived suppressor cell-enriched cell population in noninjured rodent incisor dental pulp. The percentage of this population, known to regulate immune response, was higher 9 h after inflammation triggered with PBS and LPS as compared with the control. Taken together, these data offer a better understanding of the mechanisms involved in the regulation of dental pulp immunity that may be elicited by gram-negative bacteria. PMID:26472753

  17. Experimental demonstration of population inversion driven by retroreflection-induced bichromatic adiabatic passage

    SciTech Connect

    Conde, Alvaro Peralta; Yatsenko, Leonid P.; Klein, Jens; Oberst, Martin; Halfmann, Thomas

    2005-11-15

    We present experimental data to demonstrate coherently driven population inversion by retroreflection-induced bichromatic adiabatic passage in metastable helium atoms. Complete and robust population transfer from an initial to a target state is induced by coherent interaction of the atoms in a supersonic beam with two counterpropagating and temporally delayed laser pulses of different intensities. The radiation fields intersect the atomic beam slightly tilted away from normal incidence, thereby inducing Doppler shifts of the atomic resonance between the initial and the target state. Thus the laser pulses produce a bichromatic field in the rest frame of each atom, which induces complete coherent population transfer by an adiabatic passage process.

  18. Sex differences in the intensity and qualitative dimensions of exertional dyspnea in physically active young adults.

    PubMed

    Cory, Julia M; Schaeffer, Michele R; Wilkie, Sabrina S; Ramsook, Andrew H; Puyat, Joseph H; Arbour, Brandon; Basran, Robbi; Lam, Michael; Les, Christian; MacDonald, Benjamin; Jensen, Dennis; Guenette, Jordan A

    2015-11-01

    Understanding sex differences in the qualitative dimensions of exertional dyspnea may provide insight into why women are more affected by this symptom than men. This study explored the evolution of the qualitative dimensions of dyspnea in 70 healthy, young, physically active adults (35 M and 35 F). Participants rated the intensity of their breathing discomfort (Borg 0-10 scale) and selected phrases that best described their breathing from a standardized list (work/effort, unsatisfied inspiration, and unsatisfied expiration) throughout each stage of a symptom-limited incremental-cycle exercise test. Following exercise, participants selected phrases that described their breathing at maximal exercise from a list of 15 standardized phrases. Intensity of breathing discomfort was significantly higher in women for a given ventilation, but differences disappeared when ventilation was expressed as a percentage of maximum voluntary ventilation. The dominant qualitative descriptor in both sexes throughout exercise was increased work/effort of breathing. At peak exercise, women were significantly more likely to select the following phrases: "my breathing feels shallow," "I cannot get enough air in," "I cannot take a deep breath in," and "my breath does not go in all the way." Women adopted a more rapid and shallow breathing pattern and had significantly higher end-inspiratory lung volumes relative to total lung capacity throughout exercise relative to men. These findings suggest that men and women do not differ in their perceived quality of dyspnea during submaximal exercise, but subjective differences appear at maximal exercise and may be related, at least in part, to underlying sex differences in breathing patterns and operating lung volumes during exercise. PMID:26338458

  19. Experimental gastric ulcers induced by immobilization and electric shock of rats and their pharmacotherapy

    NASA Technical Reports Server (NTRS)

    Zabrodin, O. N.

    1980-01-01

    The mechanism of development of experimental gastric ulcers, induced in rats by combined immobilization and electric shock, was analyzed pharmacologically with peripheral neurotropic agents. It is concluded that: (1) The most marked preventive effect in the development of the experimentally induced gastric ulcers was displayed by agents capable of blocking the ascending activation system of the reticular formation. (2) Sympathetic fibers, which disrupt the trophism of the gastric wall, form the efferent portion of the reflex arc. (3) Gastric secretion does not appear to be the primary cause of ulceration.

  20. A 60-year-old woman with cough, dyspnea, and atelectasis 19 years after liver transplant.

    PubMed

    Panchabhai, Tanmay S; Bandyopadhyay, Debabrata; Alraiyes, Abdul Hamid; Mehta, Atul C; Almeida, Francisco A

    2015-10-01

    A 60-year-old black woman presented with nonproductive cough of 1-month duration. She had also experienced rapidly progressive dyspnea for 1 week and one bout of vomiting a day before presentation. Her symptoms had failed to improve with a course of amoxicillin-clavulanate. Her medical history was significant for diabetes mellitus and liver transplant 19 years earlier for hepatitis C cirrhosis, for which she was receiving tacrolimus and mycophenolate. She was a current smoker with 40 pack-years of smoking history. PMID:26437820

  1. Progressive Dyspnea in a 40-Year-Old Man Caused by Giant Mediastinal Thymolipoma

    PubMed Central

    Rad, Kamelia

    2016-01-01

    Thymolipomas are rare tumors of the anterior mediastinum containing both thymic stroma and an abundance of fat. We present a 40-year-old man with no underlying disease who presented with cough and progressive dyspnea. Clinical evaluation revealed a giant mass of lipid density filling almost the entire left hemithorax with mediastinal shift. Total excision of the 40 × 33 × 8 cm mass weighing 4 kg was performed via a left thoracotomy and the histopathologic diagnosis of the mass was reported as thymolipoma. The patient remains alive and disease-free, twelve months after the intervention. PMID:27293949

  2. Dyspnea in the patient with chronic obstructive pulmonary disease. Etiology and management.

    PubMed

    Sweer, L; Zwillich, C W

    1990-09-01

    We have summarized much of the known information regarding the pathogenesis of dyspnea in the COPD patient and have reviewed a great many of the therapeutic options that have been investigated. It should be obvious that we are really in the early stages of our understanding about this symptom, and that we know very little about how to decide which treatment options are likely to succeed in any individual. At this time, there is no substitute for a careful assessment of each treatment modality that is instituted using a measurement tool, and the value of a comprehensive assessment as outlined cannot be overemphasized. PMID:1976053

  3. An uncommon case of dyspnea with unilateral laryngeal paralysis in acromegaly.

    PubMed

    Lerat, Justine; Lacoste, Marie; Prechoux, Jean-Marc; Aubry, Karine; Nadalon, Sylvie; Ly, Kim Heang; Bessede, Jean-Pierre

    2016-02-01

    A 61-year-old man with obstructive sleep apnea syndrome and normal BMI complained of dyspnea. Nasofibroscopy revealed a global and major oedema of the glottis and supraglottis and also a paralysis of the left vocal fold. CT-scan pointed out a spontaneous hyperdensity of the left arytenoid cartilage. A tracheostomy was performed. Clinical examination revealed large hands and macroglossy with high IGF1 rate. MRI confirmed a supracentimetric pituitary adenoma. To our knowledge, this is the first description of a case of acute respiratory distress due to unilateral larynx paralysis leading to acromegaly diagnosis. This is due to submucosal hypertrophy and vocal cord immobility. PMID:26142980

  4. Nutrient induced type 2 and chemical induced type 1 experimental diabetes differently modulate gastric GLP-1 receptor expression.

    PubMed

    Bloch, Olga; Broide, Efrat; Ben-Yehudah, Gilad; Cantrell, Dror; Shirin, Haim; Rapoport, Micha J

    2015-01-01

    T2DM patients demonstrate reduced GLP-1 receptor (GLP-1R) expression in their gastric glands. Whether induced T2DM and T1DM differently affect the gastric GLP-1R expression is not known. This study assessed extrapancreatic GLP-1R system in glandular stomach of rodents with different types of experimental diabetes. T2DM and T1DM were induced in Psammomys obesus (PO) by high-energy (HE) diet and by streptozotocin (STZ) in Sprague Dawly (SD) rats, respectively. GLP-1R expression was determined in glandular stomach by RT PCR and immunohistomorphological analysis. The mRNA expression and cellular association of the GLP-1R in principal glands were similar in control PO and SD rats. However, nutrient and chemical induced diabetes resulted in opposite alterations of glandular GLP-1R expression. Diabetic PO demonstrated increased GLP-1R mRNA expression, intensity of cellular GLP-1R immunostaining, and frequency of GLP-1R positive cells in the neck area of principal glands compared with controls. In contrast, SD diabetic rats demonstrated decreased GLP-1 mRNA, cellular GLP-1R immunoreactivity, and frequency of GLP-1R immunoreactive cells in the neck area compared with controls. In conclusion, nutrient and chemical induced experimental diabetes result in distinct opposite alterations of GLP-1R expression in glandular stomach. These results suggest that induced T1DM and T2DM may differently modulate GLP-1R system in enteropancreatic axis. PMID:25893200

  5. Dyspnea in divers at 49.5 ATA: mechanical, not chemical in origin.

    PubMed

    Spaur, W H; Raymond, L W; Knott, M M; Crothers, J C; Braithwaite, W R; Thalmann, E D; Uddin, D F

    1977-06-01

    Pulmonary function was studied in six divers living in a hyperbaric chamber at a pressure nearly fifty times normal (49.5 atmospheres absolute (ATA), equivalent to 488 m or 1600 ft seawater (fsw)). As expected, ventilatory function was reduced. At 49.5 ATA, maximum voluntary ventilation (MVV) was 45% less than the control value. Instantaneous rates of gas flow during forced expiration were similarly reduced, especially those flow rates measured high in the lung volume. These reductions occurred despite an apparent increase in functional residual capacity (FRC) and the use of transpulmonary pressures considerably greater than those exerted during the same maneuvers at normal (sea-level) pressure. During underwater work at 49.5 ATA, the divers rapidly became exhausted at moderate levels of oxygen consumption (1.9 liters/min), showing severe dyspnea and impending syncope. These symptoms were not due to retention of carbon dioxide, nor to hemodynamic or metabolic causes. Thus, dense gas breathing, like asthma, exemplifies a state in which severe dyspnea may occur with normal or low arterial carbon dioxide and normal oxygen transport. The physiological adjustments the divers employed were similar to those seen in acute asthma, imposing an elastic load in addition to the flow-resistive work of breathing a gas mixture eight times as dense as air. Although men can do moderate work under conditions similar to those of this experiment, they will have only a limited physiological reserve available to meet the possibilities of emergencies or respiratory infections. PMID:878071

  6. Experimental coronary sclerosis induced by immobilization of rabbits: A new model of arteriosclerosis

    NASA Technical Reports Server (NTRS)

    Tyavokin, V. V.; Tjawokin, W. W.

    1980-01-01

    A new method for producing arteriosclerosis with coronary insufficiency in rabbits by means of immobilization is described and discussed. The experimentally induced atherosclerosis develops due to hypodynamics imposed by the reduced muscular activity without overloading with exogenous cholesterol. The atherosclerosis and coronary insufficiency are associated. With variations in the duration and extent of immobilization, coronary insufficiency alone or with atherosclerosis can be produced.

  7. Modulation of celecoxib- and streptozotocin-induced experimental dementia of Alzheimer's disease by pitavastatin and donepezil.

    PubMed

    Sharma, Bhupesh; Singh, Nirmal; Singh, Manjeet

    2008-03-01

    Present study was designed to investigate modulation of experimental dementia by Pitavastatin and donepezil. Learning and memory of the swiss albino mice were studied on Morris water-maze. Celecoxib orally (p.o.)/Streptozotocin (STZ) intracerebroventricular administrations were used to induce experimental dementia. Brain acetyl cholinesterase activity was measured by EllMann's method to assess cholinergic activity of the brain. Brain thio barbituric acid reactive species (TBARS) levels and reduced glutathione (GSH) levels were measured by Ohokawa's and Beutler's method respectively, to assess total oxidative stress in brain. Total serum cholesterol level was measured by Allain's method. Celecoxib/STZ treatments produced a significant loss of learning and memory. Pitavastatin/Donepezil successfully attenuated this Celecoxib/STZ induced dementia. Higher levels of brain acetyl-cholinesterase (AChE) activity, TBARS and lower level of GSH were observed in Celecoxib/STZ treated animals, which were significantly attenuated by Donepezil. Pitavastatin also attenuated the Celecoxib/STZ induced high levels of TBARS & low levels of GSH without effecting AChE activity and total serum cholesterol levels. Celecoxib induced dementia noted in the present study may be attributed to its stimulatory effect on amyloid beta-42, brain AChE activity, and oxidative stress. Sub-diabetogenic STZ induced memory deficits closely related to Alzheimer's disease. Reversal of Celecoxib/STZ induced memory deficits by Pitavastatin may be due to its antioxidative, anti beta amyloid aggregatory property, and by Donepezil, due to its anticholinesterase and neuroprotective actions. PMID:18208924

  8. Gene Therapy Induces Antigen-Specific Tolerance in Experimental Collagen-Induced Arthritis

    PubMed Central

    Jirholt, Pernilla; Turesson, Olof; Wing, Kajsa; Holmdahl, Rikard; Kihlberg, Jan; Stern, Anna; Mårtensson, Inga-Lill; Henningsson, Louise; Gustafsson, Kenth; Gjertsson, Inger

    2016-01-01

    Here, we investigate induction of immunological tolerance by lentiviral based gene therapy in a mouse model of rheumatoid arthritis, collagen II-induced arthritis (CIA). Targeting the expression of the collagen type II (CII) to antigen presenting cells (APCs) induced antigen-specific tolerance, where only 5% of the mice developed arthritis as compared with 95% of the control mice. In the CII-tolerized mice, the proportion of Tregs as well as mRNA expression of SOCS1 (suppressors of cytokine signaling 1) increased at day 3 after CII immunization. Transfer of B cells or non-B cell APC, as well as T cells, from tolerized to naïve mice all mediated a certain degree of tolerance. Thus, sustainable tolerance is established very early during the course of arthritis and is mediated by both B and non-B cells as APCs. This novel approach for inducing tolerance to disease specific antigens can be used for studying tolerance mechanisms, not only in CIA but also in other autoimmune diseases. PMID:27159398

  9. [Dyspnea at rest and after exercise and the mental status of patients with chronic obstructive lung diseases].

    PubMed

    Borak, J; Chodosowska, E; Zieliński, J

    1992-01-01

    Thirty two patients with severe COPD were studied. We evaluated relationships between their psychological status, lung function parameters, exercises tolerance (6 MWD test) and dyspnea at rest and exercise (visual analogue scale). Patients demonstrated increased level of anxiety and psychological tension. In nearly half of the patients depression, low self-esteem and disbelief in the efficiency of therapy were observed. The correlations between the psychological status and the exercise tolerance hasn't been found. The correlation between the high level of depression and impairment of the lung function was found. The high increase in dyspnea score during exercises was connected with low self-esteem, although at rest the dyspnea level in those patients was low. PMID:1292832

  10. Four different synthetic peptides of proteolipid protein induce a distinct antibody response in MP4-induced experimental autoimmune encephalomyelitis.

    PubMed

    Recks, Mascha S; Grether, Nicolai B; van der Broeck, Franziska; Ganscher, Alla; Wagner, Nicole; Henke, Erik; Ergün, Süleyman; Schroeter, Michael; Kuerten, Stefanie

    2015-07-01

    Here we studied the autoantibody specificity elicited by proteolipid protein (PLP) in MP4-induced experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis (MS). In C57BL/6 (B6) mice, antibodies were induced by immunization with one of the two extracellular and by the intracellular PLP domain. Antibodies against extracellular PLP were myelin-reactive in oligodendrocyte cultures and induced mild spinal cord demyelination upon transfer into B cell-deficient J(H)T mice. Remarkably, also antibodies against intracellular PLP showed binding to intact oligodendrocytes and were capable of inducing myelin pathology upon transfer into J(H)T mice. In MP4-immunized mice peptide-specific T(H)1/T(H)17 responses were mainly directed against the extracellular PLP domains, but also involved the intracellular epitopes. These data suggest that both extracellular and intracellular epitopes of PLP contribute to the pathogenesis of MP4-induced EAE already in the setting of intact myelin. It remains to be elucidated if this concept also applies to MS itself. PMID:25959684

  11. DETECTORS AND EXPERIMENTAL METHODS: Equivalent properties of single event burnout induced by different sources

    NASA Astrophysics Data System (ADS)

    Yang, Shi-Yu; Cao, Zhou; Da, Dao-An; Xue, Yu-Xiong

    2009-05-01

    The experimental results of single event burnout induced by heavy ions and 252Cf fission fragments in power MOSFET devices have been investigated. It is concluded that the characteristics of single event burnout induced by 252Cf fission fragments is consistent to that in heavy ions. The power MOSFET in the “turn-off" state is more susceptible to single event burnout than it is in the “turn-on" state. The thresholds of the drain-source voltage for single event burnout induced by 173 MeV bromine ions and 252Cf fission fragments are close to each other, and the burnout cross section is sensitive to variation of the drain-source voltage above the threshold of single event burnout. In addition, the current waveforms of single event burnouts induced by different sources are similar. Different power MOSFET devices may have different probabilities for the occurrence of single event burnout.

  12. Modeling Chemotherapy-Induced Hair Loss: From Experimental Propositions toward Clinical Reality.

    PubMed

    Botchkarev, Vladimir A; Sharov, Andrey A

    2016-03-01

    Chemotherapy-induced hair loss is one of the most devastating side effects of cancer treatment. To study the effects of chemotherapeutic agents on the hair follicle, a number of experimental models have been proposed. Yoon et al. report that transplantation of human scalp hair follicles onto chemotherapy-treated immunodeficient mice serves as an excellent in vivo model for chemotherapy-induced hair loss. Yoon et al. demonstrate that (i) the response of human hair follicles grafted onto immunodeficient mice to cyclophosphamide resembles the key features of the chemotherapy-induced hair loss seen in patients with cancer and (ii) this human in vivo model for chemotherapy-induced hair loss is closer to clinical reality than to any earlier models. Undoubtedly, this model will serve as a valuable tool for analyses of the mechanisms that underlie this devastating side effect of anti-cancer therapy. PMID:26902124

  13. Peripheral site of action of levodropropizine in experimentally-induced cough: role of sensory neuropeptides.

    PubMed

    Lavezzo, A; Melillo, G; Clavenna, G; Omini, C

    1992-06-01

    The mechanism of action of levodropropizine has been investigated in different models of experimentally-induced cough in guinea-pigs. In particular it has been demonstrated that the antitussive drug has a peripheral site of action by injecting the drug intracerebroventricularly (i.c.v.). In these experiments levodropropizine (40 micrograms/50 microliters i.c.v.) did not prevent electrically-induced cough. On the other hand, codeine (5 micrograms/50 microliters i.c.v.) markedly prevented coughing. A difference in the potency ratio of levodropropizine and codeine has been demonstrated in capsaicin-induced cough; after oral administration, codeine was about two to three times more potent than levodropropizine. However, after aerosol administration the two compounds were equipotent. These data might suggest a peripheral site of action for levodropropizine which is related to sensory neuropeptides. Further support for the role of sensory neuropeptides in the mechanism of action of levodropropizine comes from the results obtained in capsaicin-desensitized animals. In this experimental model levodropropizine failed to prevent the vagally elicited cough in neuropeptide-depleted animals, whereas codeine did not differentiate between control and capsaicin-treated animals. In conclusion, our results support the suggestion that levodropropizine has a peripheral site of action. In addition, the interference with the sensory neuropeptide system may explain, at least in part, its activity in experimentally-induced cough. PMID:1611233

  14. Geographic Health's Way to Prevention of Diseases: A Case Study on Arsenic Spatial Dispersion and Dyspnea in Isfahan Province

    PubMed Central

    Rashidi, Maasoume; Poursafa, Parinaz

    2014-01-01

    Background: As geographic science discusses the analysis of environment, human beings and their mutual relations, thus the field of medical geography consists of being inspired from the relations between these two factors, analyzing environmental factors, their identification them and the state of their effects on human health, as well as determining the location of these factors. Some hazards that threat human health are the results of environmental factors and the relevant pollutions. Some important categories of diseases including (Shortness of Breath or, Dyspnea) have considerable differences in various places, as observed in their spatial prevalence and distribution maps. Methods: The record of patients with Dyspnea diseases were prepared for this descriptive research, for the period of 2009-2011, from the provincial health center, with the questionnaires were excluded patients with a family history of disease and the spatial diagram for disease prevalence was drawn according to the prepared data. The arsenic geographical distribution diagram in Isfahan province was also prepared and then the relation between an element of Arsenic in the province and the Dyspnea diseases were analyzed. Results: The analyses showed that the highest rate of Arsenic is entered the soil via fertilizers to come eventually into the food cycle of humans. By analyzing the amount of used fertilizers in Isfahan province and the dispersion diagram of Arsenic in Isfahan province, it was found that the highest frequency of Arsenic is in places having agricultural base. The spatial dispersion of Dyspnea diseases also showed that the spreading of Dyspnea diseases is greater in places with higher scale of Arsenic. Conclusions: This study is a logical justification between the two diagrams to confirm the hypothesis regarding the effect of arsenic on Dyspnea. PMID:25538832

  15. The effect of home-based inspiratory muscle training on exercise capacity, exertional dyspnea and pulmonary function in COPD patients

    PubMed Central

    Bavarsad, Maryam Bakhshandeh; Shariati, Abdolali; Eidani, Esmaeil; Latifi, Mahmud

    2015-01-01

    Background: Chronic obstructive pulmonary disease (COPD) is currently the fourth cause of mortality worldwide. Patients with COPD experience periods of dyspnea, fatigue, and disability, which impact on their life. The objective of this study was to investigate the effect of short-term inspiratory muscle training on exercise capacity, exertional dyspnea, and pulmonary lung function. Materials and Methods: A randomized, controlled trial was performed. Thirty patients (27 males, 3 females) with mild to very severe COPD were randomly assigned to a training group (group T) or to a control group (group C). Patients in group T received training for 8 weeks (15 min/day for 6 days/week) with flow-volumetric inspiratory exerciser named (Respivol). Each patient was assessed before and after 8 weeks of training for the following clinical parameters: exercise capacity by 6-min walking test (6MWT), exertional dyspnea by Borg scale, and pulmonary lung function by spirometry. Patients used training together with medical treatment. The data were analyzed using paired t-test and independent t-test. Results: Results showed statistically significant increase in 6MWT at the end of the training from 445.6 ± 22.99 to 491.06 ± 17.67 meters? (P < 0.001) and statistically significant decrease in dyspnea from 3.76 ± 0.64 to 1.13 ± 0.36 (P = 0.0001) in the training group but not in the control group. The values for exercise capacity and dyspnea improved after 8 weeks in group T in comparison with group C (P = 0.001 and P = 0.0001, respectively). No changes were observed in any measure of pulmonary function in both groups. Conclusions: Short-term inspiratory muscle training has beneficial effects on exercise capacity and exertional dyspnea in COPD patients. PMID:26457101

  16. Protective effect of ketoconazole against experimentally induced gastric ulcers in rats.

    PubMed

    Al Moutaery, Ahmed R

    2003-01-01

    Recent studies suggest the critical role of inflammatory mediators in the genesis and healing of gastric ulcers. Ketoconazole a commonly used anti-fungal agent has a potent immunomodulatory action. The present investigation was undertaken to study the effect of ketoconazole on chemically and stress induced gastric ulcers in rats. Experimental gastric lesions in rats were induced by water immersion restraint stress, indomethacin and ethanol. Acid secretion studies were undertaken in pylorus ligated rats with and without ketoconazole. The level of myeloperoxidase (marker of neutrophil activity) non-protein sulfhydryl compounds and gastric wall mucus were measured after ethanol induced gastric lesions. Ketoconazole treatment resulted in significant protection against stress; indomethacin and ethanol induced gastric lesions in rats. Ketoconazole also dose dependently attenuated ethanol induced increase in myeloperoxidase activity and protected gastric mucosa against ethanol-induced depletion of non-protein sulfhydryl. These findings point towards the mediation of neutrophils and sulfhydryl compounds in ketoconazole induced cytoprotection. In conclusion, this study clearly shows anti-acid secretory, anti-ulcer and cytoprotective activity of ketoconazole. PMID:15686104

  17. Experimental Branch Retinal Vein Occlusion Induces Upstream Pericyte Loss and Vascular Destabilization

    PubMed Central

    Dominguez, Elisa; Raoul, William; Calippe, Bertrand; Sahel, José-Alain; Guillonneau, Xavier; Paques, Michel; Sennlaub, Florian

    2015-01-01

    Aims Branch retinal vein occlusion (BRVO) leads to extensive vascular remodeling and is important cause of visual impairment. Although the vascular morphological changes following experimental vein occlusion have been described in a variety of models using angiography, the underlying cellular events are ill defined. Methods and Results We here show that laser-induced experimental BRVO in mice leads to a wave of TUNEL-positive endothelial cell (EC) apoptosis in the upstream vascular network associated with a transient edema and hemorrhages. Subsequently, we observe an induction of EC proliferation within the dilated vein and capillaries, detected by EdU incorporation, and the edema resolves. However, the pericytes of the upstream capillaries are severely reduced, which was associated with continuing EC apoptosis and proliferation. The vascular remodeling was associated with increased expression of TGFβ, TSP-1, but also FGF2 expression. Exposure of the experimental animals to hypoxia, when pericyte (PC) dropout had occurred, led to a dramatic increase in endothelial cell proliferation, confirming the vascular instability induced by the experimental BRVO. Conclusion Experimental BRVO leads to acute endothelial cells apoptosis and increased permeability. Subsequently the upstream vascular network remains destabilized, characterized by pericyte dropout, un-physiologically high endothelial cells turnover and sensitivity to hypoxia. These early changes might pave the way for capillary loss and subsequent chronic ischemia and edema that characterize the late stage disease. PMID:26208283

  18. A 29-Year-Old Man With Nonproductive Cough, Exertional Dyspnea, and Chest Discomfort.

    PubMed

    Halpenny, Darragh; Suh, James; Garofano, Suzette; Alpert, Jeffrey

    2015-09-01

    A 29-year-old man presented with a 5-month history of worsening dry cough, exertional dyspnea, chest tightness, and palpitations. He had been treated by his primary care physician with trials of guaifenesin/codeine, azithromycin, albuterol, and omeprazole without improvement. He denied wheezing, fever, sweats, anorexia, joint pain, swelling, or rash. He had no past medical history. He denied a history of tobacco smoking or IV drug use. He kept no pets, worked as a manager in an office environment, and had no history of occupational inhalational exposure. He reported using aerosolized insect spray to eradicate bed bugs in his house shortly before the cough began but did not report any acute symptoms when using the spray. PMID:26324141

  19. Primary anaplastic large cell lymphoma of trachea with subcutaneous emphysema and progressive dyspnea.

    PubMed

    Khodadad, K; Karimi, S; Arab, M; Esfahani-Monfared, Z

    2011-01-01

    Primary anaplastic large cell lymphoma of the trachea is a rare tumor. Common complaints are dyspnea and cough that could mimic a partially refractory asthma in some cases. We report a 16-year-old female with an anaplastic large cell lymphoma (null cell type) in which tracheal involvement was presented with life-threatening airway obstruction and subcutaneous emphysema. After debulking the tumor by endobronchial curettage, the patient was treated with chemotherapy followed by local radiotherapy. She had no evidence of local or distant recurrence after 25 months. Primary anaplastic large cell lymphoma of the trachea is a rare life-threatening disease. Nevertheless, this condition has a good prognosis if diagnosed immediately and treated with chemotherapy and radiotherapy. PMID:22198193

  20. Gastroprotective effect of minocycline in experimentally induced gastric ulcers in rats.

    PubMed

    Asmari, Abdulrahman Al; Omani, Saud Al; Otaibi, Malfi Al; Abdulaaly, Abdul-Aziz Al; Elfaki, Ibrahim; Yahya, Khalid Al; Arshaduddin, Mohammed

    2014-01-01

    Minocycline (MCN), a semi-synthetic tetracycline derivative possesses pleiotropic effects and provides protection against a number of disease models. However its effect on gastric ulcers has not been studied. The present investigation was undertaken, to study the gastro-protective potential of MCN in experimentally induced gastric ulcers in rats. MCN (10, 30, 100 mg/Kg) was tested for gastric secretion and antiulcer activity in different groups of Wistar rats. Gastric secretion and acidity studies were performed in pylorus ligated rats while indices of gastric ulcers were measured in ethanol (1 ml-100%) and indomethacin (30 mg/kg), induced gastric ulcers. Histological changes and the levels of gastric wall mucus, malondialdehyde (MDA), non-protein sulfhydryl (NP-SH), and myeloperoxidase (MPO), were used to assess ethanol induced gastric mucosal injuries. Exposure of rats to ulcerogens resulted in gastric mucosal injury and a significant increase in the indices of ulcer. MCN conferred a protective effect against ethanol, and indomethacin induced gastric mucosal injuries. Treatment with MCN, resulted in a significant decrease in the amount of gastric secretion, and total acidity and significantly (P<0.001), reduced the gastric lesions induced by ethanol and indomethacin. MCN also significantly attenuated the ethanol induced reduction in the levels of gastric wall mucus, and NP-SH (P<0.001). The histological changes and the increased MDA and MPO activity were also significantly (P<0.001) inhibited by MCN. Minocycline showed significant antiulcer and gastroprotective activity against experimentally induced gastric ulcers. The gastroprotective effects of minocycline may be due to its anti-secretory, antioxidant and anti inflammatory action. PMID:24753752

  1. Gastroprotective effect of minocycline in experimentally induced gastric ulcers in rats

    PubMed Central

    Asmari, Abdulrahman Al; Omani, Saud Al; Otaibi, Malfi Al; Abdulaaly, Abdul-Aziz Al; Elfaki, Ibrahim; Yahya, Khalid Al; Arshaduddin, Mohammed

    2014-01-01

    Minocycline (MCN), a semi-synthetic tetracycline derivative possesses pleiotropic effects and provides protection against a number of disease models. However its effect on gastric ulcers has not been studied. The present investigation was undertaken, to study the gastro-protective potential of MCN in experimentally induced gastric ulcers in rats. MCN (10, 30, 100 mg/Kg) was tested for gastric secretion and antiulcer activity in different groups of Wistar rats. Gastric secretion and acidity studies were performed in pylorus ligated rats while indices of gastric ulcers were measured in ethanol (1 ml-100%) and indomethacin (30 mg/kg), induced gastric ulcers. Histological changes and the levels of gastric wall mucus, malondialdehyde (MDA), non-protein sulfhydryl (NP-SH), and myeloperoxidase (MPO), were used to assess ethanol induced gastric mucosal injuries. Exposure of rats to ulcerogens resulted in gastric mucosal injury and a significant increase in the indices of ulcer. MCN conferred a protective effect against ethanol, and indomethacin induced gastric mucosal injuries. Treatment with MCN, resulted in a significant decrease in the amount of gastric secretion, and total acidity and significantly (P<0.001), reduced the gastric lesions induced by ethanol and indomethacin. MCN also significantly attenuated the ethanol induced reduction in the levels of gastric wall mucus, and NP-SH (P<0.001). The histological changes and the increased MDA and MPO activity were also significantly (P<0.001) inhibited by MCN. Minocycline showed significant antiulcer and gastroprotective activity against experimentally induced gastric ulcers. The gastroprotective effects of minocycline may be due to its anti-secretory, antioxidant and anti inflammatory action. PMID:24753752

  2. The effect of various drugs on experimentally induced ulcers in immobilized rats

    NASA Technical Reports Server (NTRS)

    Schramm, H.

    1978-01-01

    Experiments related to the importance of functional disorders in the central nervous system in connection with stomach diseases were performed on Wistar rats. Assuming that severe mental strains may be triggering factors for such disorders, testing of the effects of different drugs on experimentally induced ulcers in these rats was done. The immobilization method described by Bonfils was used. Particular importance was placed on the sex related difference which appeared.

  3. Gallic acid attenuates dextran sulfate sodium-induced experimental colitis in BALB/c mice

    PubMed Central

    Pandurangan, Ashok Kumar; Mohebali, Nooshin; Norhaizan, Mohd Esa; Looi, Chung Yeng

    2015-01-01

    Gallic acid (GA) is a polyhydroxy phenolic compound that has been detected in various natural products, such as green tea, strawberries, grapes, bananas, and many other fruits. In inflammatory bowel disease, inflammation is promoted by oxidative stress. GA is a strong antioxidant; thus, we evaluated the cytoprotective and anti-inflammatory role of GA in a dextran sulfate sodium (DSS)-induced mouse colitis model. Experimental acute colitis was induced in male BALB/c mice by administering 2.5% DSS in the drinking water for 7 days. The disease activity index; colon weight/length ratio; histopathological analysis; mRNA expressions of IL-21 and IL-23; and protein expression of nuclear erythroid 2-related factor 2 (Nrf2) were compared between the control and experimental mice. The colonic content of malondialdehyde and the activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activity were examined as parameters of the redox state. We determined that GA significantly attenuated the disease activity index and colon shortening, and reduced the histopathological evidence of injury. GA also significantly (P<0.05) reduced the expressions of IL-21 and IL-23. Furthermore, GA activates/upregulates the expression of Nrf2 and its downstream targets, including UDP-GT and NQO1, in DSS-induced mice. The findings of this study demonstrate the protective effect of GA on experimental colitis, which is probably due to an antioxidant nature of GA. PMID:26251571

  4. Experimental pathology of local tissue damage induced by Bothrops asper snake venom.

    PubMed

    Gutiérrez, José María; Rucavado, Alexandra; Chaves, Fernando; Díaz, Cecilia; Escalante, Teresa

    2009-12-01

    Envenomations by Bothrops asper are often associated with complex and severe local pathological manifestations, including edema, blistering, dermonecrosis, myonecrosis and hemorrhage. The pathogenesis of these alterations has been investigated at the experimental level. These effects are mostly the consequence of the direct action of zinc-dependent metalloproteinases (SVMPs) and myotoxic phospholipases A(2) (PLA(2)s). SVMPs induce hemorrhage, blistering, dermonecrosis and general extracellular matrix degradation, whereas PLA(2)s induce myonecrosis and also affect lymphatic vessels. In addition, the prominent vascular alterations leading to hemorrhage and edema may contribute to ischemia and further tissue necrosis. The mechanisms of action of SVMPs and PLA(2)s are discussed in detail in this review. Venom-induced tissue damage plays also a role in promoting bacterial infection. A prominent inflammatory reaction develops as a consequence of these local pathological alterations, with the synthesis and release of abundant mediators, resulting in edema and pain. However, whether inflammatory cells and mediators contribute to further tissue damage is not clear at present. Muscle tissue regeneration after venom-induced pathological effects is often impaired, thus resulting in permanent tissue loss and dysfunction. SVMP-induced microvessel damage is likely to be responsible of this poor regenerative outcome. Antivenoms are only partially effective in the neutralization of B. asper-induced local effects, and the search for novel toxin inhibitors represents a potential avenue for improving the treatment of this serious aspect of snakebite envenomation. PMID:19303033

  5. The effect of cannabinoids on dinitrofluorobenzene-induced experimental asthma in mice.

    PubMed

    Bozkurt, Turgut Emrah; Kaya, Yesim; Durlu-Kandilci, Nezahat Tugba; Onder, Sevgen; Sahin-Erdemli, Inci

    2016-09-01

    Cannabinoids have anti-inflammatory effects and can produce bronchodilation in the airways. We have investigated the effects of cannabinoids on tracheal hyperreactivity and airway inflammation in dinitrofluorobenzene (DNFB)-induced experimental non-atopic asthma in mice. 5-hydroxytryptamine (5-HT)-induced contraction response was enhanced while carbachol- and electrical field stimulation-induced contractions, and isoprenaline-induced relaxation responses were remained unchanged in DNFB group. The increased 5-HT-induced contractions were inhibited by incubation with either atropine or tetrodotoxin. DNFB application resulted in increased macrophage number in the bronchoalveolar lavage fluid (BALF). In vivo ACEA (CB1 agonist) treatment prevented the increase in 5-HT contractions, while JWH133 (CB2 agonist) had no effect. However, neither ACEA nor JWH133 prevented the increase in macrophage number in BALF. In vitro ACEA incubation also inhibited the increase in 5-HT contraction in DNFB group. These results show that cannabinoid CB1 receptor agonist can prevent tracheal hyperreactivity to 5-HT in DNFB-induced non-atopic asthma in mice. PMID:27216000

  6. Analytical and experimental study of flow phenomena in noncavitating rocket pump inducers

    NASA Technical Reports Server (NTRS)

    Lakshminarayana, B.

    1981-01-01

    The flow processes in rocket pump inducers are summarized. The experimental investigations were carried out with air as the test medium. The major characteristics features of the rocket pump inducers are low flow coefficient (0.05 to 0.2) large stagger angle (70 deg to 85 deg) and high solidity blades of little or no camber. The investigations are concerned with the effect of viscosity not the effects of cavitation. Flow visualization, conventional and hot wire probe measurement inside and at the exit of the blade passage, were the analytical methods used. The experiment was carried out using four three and two bladed inducers with cambered blades. Both the passage and the exit flow were measured. The basic research and boundary layer investigation was carried out using a helical flat plate (of some dimensions as the inducer blades tested), and flat plate helical inducer (four bladed). Detailed mean and turbulence flow field inside the passage as well as the exit of the rotor were derived from these measurement. The boundary layer, endwall, and other passage data reveal extremely complex nature of the flow, with major effects of viscosity present across the entire passage. Several analyses were carried out to predict the flow field in inducers. These included an approximate analysis, the shear pumping analysis, and a numerical solution of exact viscous equations with approximate modeling for the viscous terms.

  7. Effect of Manilkara hexandra (Roxb.) Dubard against experimentally-induced gastric ulcers.

    PubMed

    Shah, Mamta B; Goswami, S S; Santani, D D

    2004-10-01

    Effects of the flavonoid rich fraction of the stem bark of Manilkara hexandra (Roxb.) Dubard, have been studied on ethanol, ethanol-indomethacin and pylorus ligated gastric ulcers in experimental animals. Oral administration of the ethyl acetate extract (extract A3) inhibited the formation of gastric lesions induced by ethanol in a dose dependent manner. The protective effect of extract A3 against ethanol induced gastric lesions was not abolished by pretreatment with indomethacin (10 mg kg(-1)). Further, extract A3 inhibited increase in vascular permeability due to ethanol administration. Extent of lipid peroxidation was significantly reduced in animals treated with extract. Extract A3 also inhibited the formation of gastric ulcers induced by pylorus ligation, when administered both orally and intraperitoneally. Moreover, pretreatment with extract A3 increased mucus production and glycoprotein content, which was evident from the rise in mucin activity and TC: PR ratio. PMID:15551386

  8. Effects of nabumetone and dipyrone on experimentally induced gastric ulcers in rats.

    PubMed

    Yıldırım, Engin; Sağıroğlu, Oya; Kılıç, Fatma S; Erol, Kevser

    2013-04-01

    Nabumetone and dipyrone are non-acidic, nonsteroidal anti-inflammatory drugs. Both of them are known to have weak inhibitory effects of cyclooxygenases. Gastric side effects represent the most common adverse drug effects of the widely used nonsteroidal anti-inflammatory drugs. The gastric effects of these drugs may be comparable in experimental ulcer models. In the present study, the gastric ulcerogenic activity of nabumetone and dipyrone were investigated on stress- and diethyldithiocarbamate-induced experimental ulcer models by determining the ulcer index and gastric mucus secretion in rats. It was found that diethyldithiocarbamate increased both ulcer index and mucus secretion. Nabumetone inhibited dose-dependently the increase of diethyldithiocarbamate-induced mucus secretion. Dipyrone inhibited both stress- and diethyldithiocarbamate-induced ulcer index and mucus secretion. Nabumetone inhibited stress-induced ulcer index at 25-mg/kg dose but stimulated dose-dependently mucus secretion. These effects may be attributed to their non-acidic structures and weak inhibitory effects on gastric mucosal cyclooxygenases. PMID:23129452

  9. Effect of ranitidine on healing of experimentally induced gastric ulcers in ponies.

    PubMed

    MacAllister, C G; Sangiah, S

    1993-07-01

    Thirty young ponies were examined endoscopically for evidence of gastric ulceration. Seven ponies had noninduced gastric ulcers present at the initial examination and were eliminated from the study. In an attempt to induce gastric ulcers experimentally, flunixin meglumine (1.1 mg/kg of body weight, IM, q 8 h) was administered for 7 days to the 23 ponies with endoscopically normal gastric mucosa. During the 7 days of flunixin administration, 11 ponies developed gastric ulcers that were appropriate for study. The 11 ponies were randomly allotted to 2 groups. Group-A (n = 5) and group-B (n = 6) ponies received ranitidine (4.4 mg/kg, PO, q 8 h) and corn syrup, respectively, until ulcers healed or for a maximum of 40 days. General anesthesia was induced every 3 to 5 days for visual evaluation of ulcer healing by use of a video endoscope. The earliest complete healing of gastric lesions observed in a corn syrup-treated pony was at 17 days. At 40 days, 3 of 5 and 3 of 6 ponies of the ranitidine and corn syrup-treated groups, respectively, had healed ulcers. Results of this study indicate that: noninduced gastric ulcers may be common in young ponies, flunixin meglumine may be effective in inducing gastric ulcers for gastric healing studies in young ponies, and ranitidine (4.4 mg/kg, q 8 h) is not significantly effective in accelerating healing of experimentally induced gastric ulcers in ponies under conditions of this study. PMID:8368605

  10. Duration of Analgesia Induced by Acupuncture-Like TENS on Experimental Heat Pain

    PubMed Central

    Brochu, Marilyne; Dupuis-Michaud, Cynthia; Pagé, Catherine; Popovic, Draga; Simard, Marie-Eve

    2013-01-01

    Background. Acupuncture-like TENS (AL-TENS) is a treatment modality that can be used to temporarily reduce pain. However, there is no clear data in the literature regarding the specific duration of analgesia induced by AL-TENS. Objectives. To describe and quantify the duration and magnitude of AL-TENS analgesia on experimental heat pain in healthy subjects and verify if the duration or magnitude of analgesia induced by the AL-TENS was influenced by the duration of the application of the AL-TENS (15 versus 30 minutes). Methods. A repeated-measures, intrasubject randomized experimental design was used, where each participant was his/her own control. 22 healthy volunteers underwent heat pain stimulations with a contact thermode before (pretest) and after (posttest) AL-TENS application (15 and 30 minutes). Outcome measures included subjective pain during AL-TENS, duration, and magnitude of AL-TENS-induced analgesia. Results. Survival analysis showed that the median duration of AL-TENS analgesia was 10 minutes following the application of either 15 or 30 minutes of AL-TENS. The magnitude of analgesia following either application was comparable at all points in time (P values > 0.05) and ranged between −20% and −36% pain reduction. Conclusion. Only half of the participants still had heat-pain analgesia induced by the AL-TENS at 15 minutes postapplication. PMID:27335882

  11. Ambient particulate matter induces an exacerbation of airway inflammation in experimental asthma: role of interleukin-33

    PubMed Central

    Shadie, A M; Herbert, C; Kumar, R K

    2014-01-01

    High levels of ambient environmental particulate matter (PM10 i.e. < 10 μm median aerodynamic diameter) have been linked to acute exacerbations of asthma. We examined the effects of delivering a single dose of Sydney PM10 by intranasal instillation to BALB/c mice that had been sensitized to ovalbumin and challenged repeatedly with a low (≈3 mg/m3) mass concentration of aerosolized ovalbumin for 4 weeks. Responses were compared to animals administered carbon black as a negative control, or a moderate (≈30 mg/m3) concentration of ovalbumin to simulate an allergen-induced acute exacerbation of airway inflammation. Delivery of PM10 to mice, in which experimental mild chronic asthma had previously been established, elicited characteristic features of enhanced allergic inflammation of the airways, including eosinophil and neutrophil recruitment, similar to that in the allergen-induced exacerbation. In parallel, there was increased expression of mRNA for interleukin (IL)-33 in airway tissues and an increased concentration of IL-33 in bronchoalveolar lavage fluid. Administration of a monoclonal neutralizing anti-mouse IL-33 antibody prior to delivery of particulates significantly suppressed the inflammatory response induced by Sydney PM10, as well as the levels of associated proinflammatory cytokines in lavage fluid. We conclude that IL-33 plays a key role in driving airway inflammation in this novel experimental model of an acute exacerbation of chronic allergic asthma induced by exposure to PM10. PMID:24730559

  12. Opioid-induced hyperalgesia (OIH): a real clinical problem or just an experimental phenomenon?

    PubMed

    Eisenberg, Elon; Suzan, Erica; Pud, Dorit

    2015-03-01

    Although opioid-induced hyperalgesia (OIH) is mentioned as a potential cause of opioid dose escalation without adequate analgesia, true evidence in support of this notion is relatively limited. Most studies conducted in the context of acute and experimental pain, which seemingly demonstrated evidence for OIH, actually might have measured other phenomena such as acute opioid withdrawal or tolerance. OIH studies in patients with chronic pain have used various experimental pain models (such as cold pain tolerance or heat pain intensity). Therefore, the fact that they have yielded inconsistent results is hard to interpret. Thus far, with the exception of a few clinical case reports on OIH in patients with cancer pain and one prospective study in patients with chronic neuropathic pain, evidence for OIH in patients with chronic or cancer-related pain is lacking. Whether experimental pain models are necessary for establishing the clinical diagnosis of OIH, and which specific model is preferred, are yet to be determined. PMID:25128284

  13. Experimental and theoretical characterization of deep penetration welding threshold induced by 1-μm laser

    NASA Astrophysics Data System (ADS)

    Zou, J. L.; He, Y.; Wu, S. K.; Huang, T.; Xiao, R. S.

    2015-12-01

    The deep penetration-welding threshold (DPWT) is the critical value that describes the welding mode transition from the thermal conduction to the deep penetration. The objective of this research is to clarify the DPWT induced by the lasers with wavelength of 1 μm (1-μm laser), based on experimental observation and theoretical analysis. The experimental results indicated that the DPWT was the ratio between laser power and laser spot diameter (P/d) rather than laser power density (P/S). The evaporation threshold was smaller than the DPWT, while the jump threshold of the evaporated mass flux in the molten pool surface was consistent with the DPWT. Based on the force balance between the evaporation recoil pressure and the surface tension pressure at the gas-liquid interface of the molten pool as well as the temperature field, we developed a self-focusing model, which further confirmed the experimental results.

  14. Inflammation-induced pain sensitization in men and women: does sex matter in experimental endotoxemia?

    PubMed

    Wegner, Alexander; Elsenbruch, Sigrid; Rebernik, Laura; Roderigo, Till; Engelbrecht, Elisa; Jäger, Marcus; Engler, Harald; Schedlowski, Manfred; Benson, Sven

    2015-10-01

    A role of the innate immune system is increasingly recognized as a mechanism contributing to pain sensitization. Experimental administration of the bacterial endotoxin lipopolysaccharide (LPS) constitutes a model to study inflammation-induced pain sensitization, but all existing human evidence comes from male participants. We assessed visceral and musculoskeletal pain sensitivity after low-dose LPS administration in healthy men and women to test the hypothesis that women show greater LPS-induced hyperalgesia compared with men. In this randomized, double-blind, placebo-controlled crossover study, healthy men (n = 20) and healthy women using oral contraceptives (n = 20) received an intravenous injection of 0.4 ng/kg body weight LPS or placebo. Pain sensitivity was assessed with established visceral and musculoskeletal pain models (ie, rectal pain thresholds; pressure pain thresholds for different muscle groups), together with a heartbeat perception (interoceptive accuracy) task. Plasma cytokines (tumor necrosis factor-α and interleukin-6) were measured along with state anxiety at baseline and up to 6-hour postinjection. Lipopolysaccharide application led to significant increases in plasma cytokines and state anxiety and decreased interoceptive awareness in men and women (P < 0.001, condition effects), with more pronounced LPS-induced cytokine increases in women (P < 0.05, interaction effects). Although both rectal and pressure pain thresholds were significantly decreased in the LPS condition (all P < 0.05, condition effect), no sex differences in endotoxin-induced sensitization were observed. In summary, LPS-induced systemic immune activation leads to visceral and musculoskeletal hyperalgesia, irrespective of biological sex. These findings support the broad applicability of experimental endotoxin administration as a translational preclinical model of inflammation-induced pain sensitization in both sexes. PMID:26058036

  15. Agreement between a simple dyspnea-guided treatment algorithm for stable COPD and the GOLD guidelines: a pilot study

    PubMed Central

    Cabrera, Carlos; Casanova, Ciro; Martín, Yolanda; Mirabal, Virginia; Sánchez, María del Carmen; Álvarez, Felisa; Juliá, Gabriel; Cabrera-Navarro, Pedro; García-Bello, Miguel Ángel; Marín, José María; de-Torres, Juan Pablo; Divo, Miguel; Celli, Bartolomé

    2016-01-01

    Introduction Guidelines recommendations for the treatment of COPD are poorly followed. This could be related to the complexity of classification and treatment algorithms. The purpose of this study was to validate a simpler dyspnea-based treatment algorithm for inhaled pharmacotherapy in stable COPD, comparing its concordance with the current Global Initiative for Obstructive Lung Disease (GOLD) guideline. Methods We enrolled patients who had been diagnosed with COPD in three primary care facilities and two tertiary hospitals in Spain. We determined anthropometric data, forced expiratory volume in the 1st second (percent), exacerbations, and dyspnea based on the modified Medical Research Council scale. We evaluated the new algorithm based on dyspnea and exacerbations and calculated the concordance with the current GOLD recommendations. Results We enrolled 100 patients in primary care and 150 attending specialized care in a respiratory clinic. There were differences in the sample distribution between cohorts with 41% vs 26% in grade A, 16% vs 12% in grade B, 16% vs 22% in grade C, and 27% vs 40% in grade D for primary and respiratory care, respectively (P=0.005). The coincidence of the algorithm with the GOLD recommendations in primary care was 93% and 91.8% in the respiratory care cohort. Conclusion A simple dyspnea-based treatment algorithm for inhaled pharmacotherapy of COPD could be useful in the management of COPD patients and concurs very well with the recommended schema suggested by the GOLD initiative. PMID:27354780

  16. Effects of everolimus on a rat model of cerulein-induced experimental acute pancreatitis

    PubMed Central

    Özkardeş, Alper Bilal; Bozkurt, Birkan; Dumlu, Ersin Gürkan; Tokaç, Mehmet; Yazgan, Aylin Kılıç; Ergin, Merve; Erel, Özcan; Kılıç, Mehmet

    2015-01-01

    Objective: To analyze the biochemical and histopathological effects of everolimus in an experimental rat model of cerulein-induced acute pancreatitis. The aim of the present study was to determine the effects of everolimus on blood biochemical parameters and tissue histopathology in an experimental rat model of cerulein-induced acute pancreatitis. Material and Methods: In 30 Wistar albino rats (male; 240–260 g), acute pancreatitis was induced by an intraperitoneal injection of cerulein (50 μg/kg) administered twice in 2 h. They were equally divided into the following three groups: 0.9% isotonic solution (Group 1; control), everolimus once (Group 2), and everolimus twice (Group 3) by oral gavage after cerulein injection. Thirty hours after the induction of pancreatitis, blood samples were collected by direct intracardiac puncture, rats were sacrificed, and pancreatic tissue samples were obtained. Results: Biochemical analyses of the blood samples showed statistically significant difference in red blood cell count as well as hemoglobin, hematocrit, urea, and alanine transaminase levels among the study groups (p<0.05 in all). Everolimus proved to significantly increase red blood cell count in a dose-independent manner. Hemoglobin and hematocrit levels significantly increased only after treatment with one dose of everolimus. Urea level was significantly different between the Groups 2 and 3; however, no change was observed in both groups when compared with the control. Alanine transaminase level significantly decreased only after treatment with two doses of everolimus. Histopathological analyses revealed that everolimus significantly decreased inflammation and perivascular infiltrate in a dose-dependent manner (35% in Group 2, 75% in Group 3; p=0.048). Conclusion: Treatment with two doses of everolimus improved some biochemical and histopathological parameters of experimental rat models of cerulein-induced acute pancreatitis and implied the specific inhibition of

  17. Usefulness of the culturally adapted oxygen-cost diagram in the assessment of dyspnea in Puerto Rico

    PubMed Central

    Santos Rodríguez, Ruth A.; Dexter, Donald; Nieves-Plaza, Mariely; Nazario, Cruz M.

    2015-01-01

    Objective Breathlessness is a common and disabling symptom of pulmonary disease. Measuring its severity is recommended as such measurements can be helpful in both clinical and research settings. The oxygen-cost diagram (OCD) and the Medical Research Council (MRC) dyspnea scale were developed in English to measure severity of dyspnea. These scales were previously translated to Spanish and adapted for use in a Hispanic population. The objective of this study is to assess the psychometric properties of these scales. We propose the scales correlate well with measures of physiological impairment. Methods Subjects having pulmonary disease rated their perceptions of dyspnea using the scales, performed a spirometry test, and did a 6-min walk. Spearman correlation coefficients (r) were used to correlate dyspnea scores with spirometric parameters and distance walked (6MWD). Results Sixty-six patients having stable asthma (n = 36), chronic obstructive pulmonary disease (n = 19), or interstitial lung disease (n = 11) participated in the study. OCD scores showed a significant correlation with FEV1 (r = 0.41; p<0.01), FEV1% (r = 0.36; p<0.01), FVC (r = 0.44; p<0.01), and FVC% (r = 0.37; p<0.01) in the study population. The OCD scores were highly correlated with 6MWD (r = 0.59, p<0.01). The MRC dyspnea scale showed significant inverse correlation with FEV1 (r = −0.34; p<0.01) and 6MWD (r = −0.33; p<0.05), but the correlations were weaker compared to the correlations with the OCD scale. Conclusions The severity of breathlessness as measured by the adapted Spanish OCD showed a moderate to high correlation with spirometric parameters and 6MWD; therefore, the adapted OCD should prove to be useful in Puerto Rico. PMID:25856872

  18. Protective effect of leaves of Raphinus sativus Linn on experimentally induced gastric ulcers in rats.

    PubMed

    Devaraj, V C; Gopala Krishna, B; Viswanatha, G L; Satya Prasad, V; Vinay Babu, S N

    2011-07-01

    Raphinus sativus Linn (Cruciferae) commonly known as 'Radish' is a multipurpose herb cultivated in different parts of the world for its edible roots and leaves. The present study was aimed to evaluate the antiulcer activity of leaf extracts of R. sativus Linn on acetic acid induced chronic gastric ulcer and pylorus ligation induced gastric ulcer in rats. The acute oral toxicity study revealed that all the extracts were safe up to 2000 mg/kg per oral dose; hence one-tenth of this dose was selected for evaluation of antiulcer activity. In acetic acid induced gastric ulcer models, the ERS, CRS, EARS and AQRS have offered significant protection against acetic acid induced ulcers when compared to control group. While in pylorus ligation induced ulcer model the ERS, EARS and AQRS showed significant protection by decreasing the ulcer index, total acidity and free acidity. In conclusion the leaf extracts of R. sativus Linn are found to possess antiulcer property in the experimental animal models of gastric ulcers, which is consistent with the literature report in the folk medicine. PMID:23960756

  19. Effects of Guchang Capsule on Dextran Sulphate Sodium-Induced Experimental Ulcerative Colitis in Mice

    PubMed Central

    Liu, Baoshan; Liu, Tong; Wang, Xiaohong; Zheng, Xin; Wang, Hong; Ma, Lin

    2016-01-01

    Guchang capsule (GC) is a Chinese materia medica standardized product extracted from 15 Chinese traditional medical herbs and it has been clinically used in the treatment of intestinal disease. In this study, in order to extend the research of GC in intestinal disease, we were aiming to evaluate potential effects of GC on dextran sulphate sodium- (DSS-) induced murine experimental colitis and to elucidate the underlying mechanisms. GC treatment attenuated DSS-induced body weight loss and reduced the mortality. Moreover, GC treatment prevented DSS-induced colonic pathological damage; meanwhile it inhibited proinflammatory cytokines production in colon tissues. In vitro, GC significantly reduced LPS-induced proinflammatory cytokines production via inhibiting the activation of NF-κB in macrophage cells, and the expressions of several long noncoding RNAs (lncRNAs) which were reported in regulating NF-κB signaling pathway were obviously affected by adding GC into culture medium. In conclusion, our data suggested that administration of GC exhibits therapeutic effects on DSS-induced colitis partially through regulating the expression of NF-κB related lncRNAs in infiltrating immune cells. PMID:27313642

  20. Experimental rat model for alcohol-induced osteonecrosis of the femoral head

    PubMed Central

    Okazaki, Shunichiro; Nagoya, Satoshi; Tateda, Kenji; Katada, Ryuichi; Mizuo, Keisuke; Watanabe, Satoshi; Yamashita, Toshihiko; Matsumoto, Hiroshi

    2013-01-01

    Alcohol-induced osteonecrosis of the femoral head (ONFH) is observed in alcohol abusers and patients with alcoholic fatty liver disease. It has been reported that Toll-like receptor 4 (TLR4) signalling plays a crucial role in the pathogenesis of alcoholic fatty liver disease. We previously reported a corticosteroid-induced ONFH rat model, and suggested that TLR4 signalling contributes to the pathogenesis of ONFH. Thus, it is thought that the pathogenesis of alcohol-induced ONFH is probably similar to that of corticosteroid-induced ONFH. The aim of this study was to develop a new animal model for alcohol-induced ONFH and to evaluate the relationship between the pro-inflammatory response via TLRs and the development of ONFH in rats. Male Wistar rats were fed a Lieber–DeCarli liquid diet containing 5% ethanol (experimental group) or dextran (control group) for 1–24 weeks. Histopathological and biochemical analyses were performed. Feeding the ethanol-containing liquid diet resulted in the development of ONFH with hepatic steatosis, hepatic dysfunction and hyperlipidaemia, whereas feeding the dextran-containing diet did not cause ONFH. However, we could not recognize any relationship between the pro-inflammatory response via TLR4 and the development of alcohol-induced ONFH. Thus in this study we have developed a new rat model for alcohol-induced ONFH based on the feeding of an ethanol liquid diet. ONFH was observed within seven days from the start of feeding with 5% ethanol-containing liquid diet. Although this was linked to hepatic steatosis, a TLR4 association was not a feature of this model. PMID:24020403

  1. Interferon-inducible protein-10 is highly expressed in rats with experimental nephrosis.

    PubMed Central

    Gómez-Chiarri, M.; Ortiz, A.; González-Cuadrado, S.; Serón, D.; Emancipator, S. N.; Hamilton, T. A.; Barat, A.; Plaza, J. J.; González, E.; Egido, J.

    1996-01-01

    Interferon-inducible protein (IP)-10 is a small glycoprotein member of a family of chemotactic cytokines structurally related to interleukin-8. We have recently described the induction of IP-10 mRNA in mouse mesangial cells stimulated with lipopolysacharide, interferon-gamma, and tumor necrosis factor-alpha. To further evaluate a possible role for this chemokine in renal injury, we have studied IP-10 in an experimental model of nephrosis induced in rats by adriamycin. High levels of glomerular IP-10 mRNA expression and glomerular and tubulointerstitial IP-10 protein were seen on day 21, coinciding with maximal proteinuria, glomerular tumor necrosis factor mRNA expression, and interstitial cellular infiltrates. Maintenance on a low protein diet not only delayed the appearance of proteinuria and interstitial cellular infiltrate but also decreased glomerular IP-10 mRNA expression. Isolated normal glomeruli and cultured glomerular epithelial and mesangial cells from normal rats expressed IP-10 mRNA upon stimulation with 100 U/ml interferon or 1 microgram/ml lipopolysaccharide for 3 hours. IP-10 mRNA expression was also inducible by lipopolysaccharide and cytokines in NRK 49F renal interstitial fibroblasts and, to a lesser extent, in NRK 52E tubular epithelial cells. Furthermore, IP-10 protein was inducible in murine mesangial cells. We conclude that IP-10 is highly inducible in vitro and in vivo in resident glomerular and tubulointerstitial cells. IP-10 may participate in the modulation of renal damage in experimental nephrosis. Images Figure 1 Figure 2 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:8546219

  2. Experimental investigations on flow induced vibration of an externally excited flexible plate

    NASA Astrophysics Data System (ADS)

    Purohit, Ashish; Darpe, Ashish K.; Singh, S. P.

    2016-06-01

    Flow-induced vibration of a harmonically actuated flexible plate in the wake of an upstream bluff body is experimentally investigated. The experiments are performed in an open-ended wind tunnel. A flexible plate trailing a bluff body is under fluid induced excitation due to the flowing fluid. The additional external excitation to the trailing plate is applied using an electro-magnetic exciter. The frequency and amplitude of the external harmonic excitation are selected as variable parameters in the experiments and their effect on the plate vibration and is investigated. To know the nature of acoustic pressure wave generated from the vibrating system, near-field acoustic pressure is also measured. A laser vibrometer, a pressure microphone and a high-speed camera are employed to measure the plate vibration, pressure signal, and instantaneous images of the plate motion respectively. The results obtained indicate that the dynamics of the plate is influenced by both the flow-induced excitation and external harmonic excitation. When frequency of the two excitations is close enough, a large vibration level and a high tonal sound pressure are observed. At higher amplitude of external excitation, the frequency component corresponding to the flow-induced excitation is found to reduce significantly in the frequency spectrum of the vibration signal. It is observed that, for certain range of excitation frequency, the plate vibration first reduces, reaches a minimum value and then increases with increase in the level of external excitation. A fair qualitative agreement of the experimental results with numerical simulation result of the past study has been noted. In addition to the experiments, the role of phase difference between the flow-induced excitation generated from the front obstacle and externally applied harmonic excitation is investigated through numerical simulations. The result obtained reveals that the final steady state vibration of the coupled system is

  3. Effects of experimentally-induced maternal hypothyroidism on crucial offspring rat brain enzyme activities.

    PubMed

    Koromilas, Christos; Liapi, Charis; Zarros, Apostolos; Stolakis, Vasileios; Tsagianni, Anastasia; Skandali, Nikolina; Al-Humadi, Hussam; Tsakiris, Stylianos

    2014-06-01

    Hypothyroidism is known to exert significant structural and functional changes to the developing central nervous system, and can lead to the establishment of serious mental retardation and neurological problems. The aim of the present study was to shed more light on the effects of gestational and/or lactational maternal exposure to propylthiouracil-induced experimental hypothyroidism on crucial brain enzyme activities of Wistar rat offspring, at two time-points of their lives: at birth (day-1) and at 21 days of age (end of lactation). Under all studied experimental conditions, offspring brain acetylcholinesterase (AChE) activity was found to be significantly decreased due to maternal hypothyroidism, in contrast to the two studied adenosinetriphosphatase (Na(+),K(+)-ATPase and Mg(2+)-ATPase) activities that were only found to be significantly altered right after birth (increased and decreased, respectively, following an exposure to gestational maternal hypothyroidism) and were restored to control levels by the end of lactation. As our findings regarding the pattern of effects that maternal hypothyroidism has on the above-mentioned crucial offspring brain enzyme activities are compared to those reported in the literature, several differences are revealed that could be attributed to both the mode of the experimental simulation approach followed as well as to the time-frames examined. These findings could provide the basis for a debate on the need of a more consistent experimental approach to hypothyroidism during neurodevelopment as well as for a further evaluation of the herein presented and discussed neurochemical (and, ultimately, neurodevelopmental) effects of experimentally-induced maternal hypothyroidism, in a brain region-specific manner. PMID:24632022

  4. The effect of topical metronidazole therapy on experimentally-induced periodontitis in the beagle dog.

    PubMed

    Klinge, B; Kuvatanasuhati, J; Attström, R; Kalfas, S; Edwardsson, S

    1992-10-01

    The present study was performed to assess the effect of topical metronidazole therapy on ligature-induced periodontitis in beagle dogs. 6 beagle dogs with experimentally-induced periodontitis on the mandibular 2nd, 3rd and 4th premolars were treated with metronidazole 10% dental paste 2 x daily for 4 weeks in an open placebo-controlled study using a split-mouth design. Recordings of probing pocket depth, bleeding on probing and gingival index were performed before commencement of treatment and repeated weekly during the 4-weeks treatment period. Concurrently, samples for microbiological analysis were collected from 2 of the dogs. The results demonstrated that probing pocket depth, bleeding on probing and gingival index had improved significantly in the metronidazole-treated side compared with the placebo-treated side. Black pigmented Bacteroides spp. and Spirochetes, present in all samples before treatment, were eliminated from the metronidazole-treated side after the 1st week of treatment and throughout the treatment period, whereas they were present in all samples from the placebo-treated side. The result of the present study demonstrates that topical application of metronidazole in a dental paste, improves the clinical features of the experimentally-induced periodontitis and eliminates some of the micro-organisms associated with the disease. PMID:1447390

  5. Effects of aescin on testicular repairment in rats with experimentally induced varicocele.

    PubMed

    Tian, R H; Ma, M; Zhu, Y; Yang, S; Wang, Z Q; Zhang, Z S; Wan, C F; Li, P; Liu, Y F; Wang, J L; Liu, Y; Yang, H; Zhang, Z Z; Liu, L H; Gong, Y H; Li, F H; Hu, H L; He, Z P; Huang, Y R; Li, Z

    2014-06-01

    This study was conducted to investigate the effects of aescin treatment in a rodent model treated with an experimentally induced varicocele. Experimental varicocele was induced by partial ligation of the left renal vein of rats. Aescin administration was performed daily for 4 weeks after the varicocele induction. Seven weeks later, a contrast-enhanced ultrasound was performed of the rats' testis to assess testicular blood flow. The animals were sacrificed, and H&E staining was then used to evaluate testicular pathological changes and polymorphonuclear leucocytes density. Cauda epididymal sperm counts and motility were evaluated. Blood was collected for the measurement of follicle-stimulating hormone, luteinising hormone and testosterone. Contrast-enhanced ultrasound showed that there were significant decreases in testicular blood flow in the aescin-treated groups compared with those in control varicocele group. Testicular oedema was detected in those rats treated with a varicocele but without aescin, while no oedema was found in the experimental group. H&E staining showed dysfunctional spermatogenesis in both cohorts; however, polymorphonuclear leucocytes density was significantly reduced in aescin-treated groups. There was an increase in sperm counts of the aescin-treated groups. Our study demonstrated that aescin could exert therapeutical effects on reversal of testicular lesions in varicocele rats. PMID:23682825

  6. The effect of experimentally induced sedentariness on mood and psychobiological responses to mental stress

    PubMed Central

    Endrighi, Romano; Steptoe, Andrew; Hamer, Mark

    2016-01-01

    Background Evidence suggests a link between sedentary behaviours and depressive symptoms. Mechanisms underlying this relationship are not understood, but inflammatory processes may be involved. Autonomic and inflammatory responses to stress may be heightened in sedentary individuals contributing to risk, but no study has experimentally investigated this. Aims To examine the effect of sedentary time on mood and stress responses using an experimental design. Method Forty-three individuals were assigned to a free-living sedentary condition and to a control condition (usual activity) in a cross-over, randomised fashion and were tested in a psychophysiology laboratory after spending 2 weeks in each condition. Participants completed mood questionnaires (General Health Questionnaire and Profile of Mood States) and wore a motion sensor for 4 weeks. Results Sedentary time increased by an average of 32 min/day (P = 0.01) during the experimental condition compared with control. Being sedentary resulted in increases in negative mood independent of changes in moderate to vigorous physical activity (ΔGHQ = 6.23, ΔPOMS = 2.80). Mood disturbances were associated with greater stress-induced inflammatory interleukin-6 (IL-6) responses (β = 0.37). Conclusions Two weeks of exposure to greater free-living sedentary time resulted in mood disturbances independent of reduction in physical activity. Stress-induced IL-6 responses were associated with changes in mood. PMID:26294364

  7. Experimental study to explore the 8Be-induced nuclear reaction via the Trojan horse method

    NASA Astrophysics Data System (ADS)

    Wen, Qun-Gang; Li, Cheng-Bo; Zhou, Shu-Hua; Irgaziev, Bakhadir; Fu, Yuan-Yong; Spitaleri, Claudio; La Cognata, Marco; Zhou, Jing; Meng, Qiu-Ying; Lamia, Livio; Lattuada, Marcello

    2016-03-01

    To explore a possible indirect method for 8Be induced astrophysical reactions, the 8Be=(8Be+n ) cluster structure has been studied via the Trojan horse method. For the first time a 8Be nucleus having an ultrashort lifetime is studied by the Trojan horse method and a 9Be nucleus in the ground state is used for this purpose. The 9Be nucleus is assumed to have a (8Be+n ) cluster structure and used as a Trojan horse nucleus. The 8Be nucleus acts as a participant, while the neutron is a spectator to the virtual 8Be+d →α +6Li reaction via the 3-body reaction 8Be+d →α +6Li+n . The experimental neutron momentum distribution inside 9Be has been reconstructed. The agreement between the experimental momentum distribution and the theoretical one indicates that a (8Be+n ) cluster structure inside 9Be is very likely. Therefore, the experimental study of 8Be induced reactions, for example, the measurement of the 8Be+α →12C reaction proceeding through the Hoyle state, is possible.

  8. Effect of somatosensory amplification and trait anxiety on experimentally induced orthodontic pain.

    PubMed

    Cioffi, Iacopo; Michelotti, Ambrosina; Perrotta, Stefania; Chiodini, Paolo; Ohrbach, Richard

    2016-04-01

    The perception of pain varies considerably across individuals and is affected by psychological traits. This study aimed to investigate the combined effects of somatosensory amplification and trait anxiety on orthodontic pain. Five-hundred and five adults completed the State Trait Anxiety Inventory (STAI) and the Somatosensory Amplification Scale (SSAS). Individuals with combined STAI and SSAS scores below the 20th percentile (LASA group: five men and 12 women; mean age ± SD = 22.4 ± 1.3 yr) or above the 80th percentile (HASA group: 13 men and seven women; mean age ± SD = 23.7 ± 1.0 yr) were selected and filled in the Oral Behaviors Checklist (OBC). Orthodontic separators were placed for 5 d in order to induce experimental pain. Visual analog scales (VAS) were administered to collect ratings for occlusal discomfort, pain, and perceived stress. Pressure pain thresholds (PPT) were measured. A mixed regression model was used to evaluate pain and discomfort ratings over the 5-d duration of the study. At baseline, the LASA group had statistically significantly higher PPT values for the masseter muscle than did the HASA group. During the experimental procedure, the HASA group had statistically significantly higher discomfort and pain. A significant difference in pain ratings during the 5 d of the study was found for subjects in the HASA group. Higher OBC values were statistically significantly positively associated with pain. Somatosensory amplification and trait anxiety substantially affect experimentally induced orthodontic pain. PMID:26918812

  9. Paricalcitol may improve oxidative DNA damage on experimental amikacin-induced nephrotoxicity model.

    PubMed

    Bulut, Gulay; Basbugan, Yildiray; Ari, Elif; Erten, Remzi; Bektas, Havva; Alp, Hamit Hakan; Bayram, Irfan

    2016-06-01

    This study aimed to investigate the possible protective effect of paricalcitol on experimental amikacin-induced nephrotoxicity model in rats. Wistar albino rats (n = 32) were allocated into four equal groups of eight each, the control (Group C), paricalcitol (Group P), amikacin-induced nephrotoxicity (Group A), and paricalcitol-treated amikacin-induced nephrotoxicity (Group A + P) groups. Paricalcitol was given intra-peritoneally at a dose of 0.4 μg/kg/d for 5 consecutive days prior to induction of amikacin-induced nephrotoxicity. Intra-peritoneal amikacin (1.2 g/kg) was used to induce nephrotoxicity at day 4. Renal function parameters, oxidative stress biomarkers, oxidative DNA damage (8-hydroxy-2'-deoxyguanosine/deoxyguanosine ratio), kidney histology, and vascular endothelial growth factor (VEGF) immunoexpression were determined. Group A + P had lower mean fractional sodium excretion (p < 0.001) as well as higher creatinine clearance (p = 0.026) than the amikacin group (Group A). Renal tissue malondialdehyde levels (p = 0.035) and serum 8-hydroxy-2'-deoxyguanosine/deoxyguanosine ratio (8-OHdG/dG ratio) (p < 0.001) were significantly lower; superoxide dismutase (p = 0.024) and glutathione peroxidase (p = 0.007) activities of renal tissue were significantly higher in group A + P than in group A. The mean scores of tubular necrosis (p = 0.024), proteinaceous casts (p = 0.038), medullary congestion (p = 0.035), and VEGF immunoexpression (p = 0.018) were also lower in group A + P when compared with group A. This study demonstrates the protective effect of paricalcitol in the prevention of amikacin-induced nephrotoxicity in an experimental model. Furthermore, it is the first study to demonstrate that paricalcitol improves oxidative DNA damage in an experimental acute kidney injury model. PMID:26983906

  10. Catechin averts experimental diabetes mellitus-induced vascular endothelial structural and functional abnormalities.

    PubMed

    Bhardwaj, Pooja; Khanna, Deepa; Balakumar, Pitchai

    2014-03-01

    Diabetes mellitus is associated with an induction of vascular endothelial dysfunction (VED), an initial event that could lead to the pathogenesis of atherosclerosis and hypertension. Previous studies showed that catechin, a key component of green tea, possesses vascular beneficial effects. We investigated the effect of catechin hydrate in diabetes mellitus-induced experimental vascular endothelial abnormalities (VEA). Streptozotocin (50 mg/kg, i.p., once) administration to rats produced diabetes mellitus, which subsequently induced VEA in 8 weeks by markedly attenuating acetylcholine-induced endothelium-dependent relaxation in the isolated aortic ring preparation, decreasing aortic and serum nitrite/nitrate concentrations and impairing aortic endothelial integrity. These abnormalities in diabetic rats were accompanied with elevated aortic superoxide anion generation and serum lipid peroxidation in addition to hyperglycemia. Catechin hydrate treatment (50 mg/kg/day p.o., 3 weeks) markedly prevented diabetes mellitus-induced VEA and vascular oxidative stress. Intriguingly, in vitro incubation of L-NAME (100 μM), an inhibitor of nitric oxide synthase, or Wortmannin (100 nM), a selective inhibitor of phosphatidylinositol 3-kinase (PI3K), markedly prevented catechin hydrate-induced improvement in acetylcholine-provoked endothelium-dependent relaxation in the diabetic rat aorta. Moreover, catechin hydrate treatment considerably reduced the elevated level of serum glucose in diabetic rats. In conclusion, catechin hydrate treatment prevents diabetes mellitus-induced VED through the activation of endothelial PI3K signal and subsequent activation of eNOS and generation of nitric oxide. In addition, reduction in high glucose, vascular oxidative stress, and lipid peroxidation might additionally contribute to catechin hydrate-associated prevention of diabetic VEA. PMID:24048981

  11. Oral Administration of Ginseng Ameliorates Cyclosporine-Induced Pancreatic Injury in an Experimental Mouse Model

    PubMed Central

    Lim, Sun Woo; Doh, Kyoung Chan; Jin, Long; Piao, Shang Guo; Heo, Seong Beom; Zheng, Yu Fen; Bae, Soo Kyung; Chung, Byung Ha; Yang, Chul Woo

    2013-01-01

    Background This study was performed to investigate whether ginseng has a protective effect in an experimental mouse model of cyclosporine-induced pancreatic injury. Methods Mice were treated with cyclosporine (30 mg/kg/day, subcutaneously) and Korean red ginseng extract (0.2 or 0.4 g/kg/day, oral gavage) for 4 weeks while on a 0.01% salt diet. The effect of ginseng on cyclosporine-induced pancreatic islet dysfunction was investigated by an intraperitoneal glucose tolerance test and measurements of serum insulin level, β cell area, macrophage infiltration, and apoptosis. Using an in vitro model, we further examined the effect of ginseng on a cyclosporine-treated insulin-secreting cell line. Oxidative stress was measured by the concentration of 8-hydroxy-2′-deoxyguanosine in serum, tissue sections, and culture media. Results Four weeks of cyclosporine treatment increased blood glucose levels and decreased insulin levels, but cotreatment with ginseng ameliorated the cyclosporine-induced glucose intolerance and hyperglycemia. Pancreatic β cell area was also greater with ginseng cotreatment compared with cyclosporine monotherapy. The production of proinflammatory molecules, such as induced nitric oxide synthase and cytokines, and the level of apoptotic cell death also decreased in pancreatic β cell with ginseng treatment. Consistent with the in vivo results, the in vitro study showed that the addition of ginseng protected against cyclosporine-induced cytotoxicity, inflammation, and apoptotic cell death. These in vivo and in vitro changes were accompanied by decreases in the levels of 8-hydroxy-2′-deoxyguanosine in pancreatic β cell in tissue section, serum, and culture media during cotreatment of ginseng with cyclosporine. Conclusions The results of our in vivo and in vitro studies demonstrate that ginseng has a protective effect against cyclosporine-induced pancreatic β cell injury via reducing oxidative stress. PMID:24009697

  12. Antidiarrhoeal activity of leaf extract of celosia argentea in experimentally induced diarrhoea in rats.

    PubMed

    Sharma, Praveen; Vidyasagar, Gali; Singh, Sunder; Ghule, Santosh; Kumar, Bimlesh

    2010-01-01

    In order to scientifically apprise some of the anecdotal, folkloric, ethno medical uses of celosia argentea, the present study was undertaken to examine the antidiarrhoeal properties of alcoholic extract of leaves of Celosia argentea on diarrhoea by using different experimental models. Anti-diarrhoeal effect was evaluated by castor oil induced diarrhoea, charcoal meal test and PGE(2) induced diarrhoea. Loperamide (2 mg/kg) and atropine (0.1mg/kg) were used as standard drugs. Extract was used in 100 and 200 mg/kg dose. It produced dose related anti-diarrhoeal effect. Results suggest that it may act centrally and may inhibit the PGE(2) to give anti-diarrhoeal effects. Result of charcoal meal test also suggests its anti-muscarinic activity. PMID:22247831

  13. The antioxidant response induced by Lonicera caerulaea berry extracts in animals bearing experimental solid tumors.

    PubMed

    Gruia, Maria Iuliana; Oprea, Eliza; Gruia, Ion; Negoita, Valentina; Farcasanu, Ileana Cornelia

    2008-01-01

    Lonicera caerulea is a species of bush native to the Kamchatka Peninsula (Russian Far East) whose berries have been extensively studied due to their potential high antioxidant activity. The aim of our work was to investigate the in vivo effects of the antioxidant action of Lonicera caerulea berry extracts on the dynamics of experimentally-induced tumors. Our data showed that aqueous Lonicera caerulaea extracts reduced the tumor volume when administered continuously during the tumor growth and development stages, but augmented the tumor growth when the administration of extracts started three weeks before tumor grafting. Prolonged administration of Lonicera caerulaea berry extracts induced the antioxidant defense mechanism in the tumor tissues, while surprisingly amplifying the peripheral oxidative stress. PMID:18560338

  14. Boehmeria nivea Attenuates the Development of Dextran Sulfate Sodium-Induced Experimental Colitis

    PubMed Central

    Shin, Eun Ju; Sung, Mi Jeong; Yang, Hye Jeong; Kim, Myung Sunny; Hwang, Jin-Taek

    2014-01-01

    We examined the therapeutic effect of an ethanol extract derived from Boehmeria nivea (Linn.) Gaudich in a mouse model of experimental colitis. Treatment with 70% ethanol extract derived from B. nivea (EBN) at a dose of 100, 200, or 500 mg/(kg·d) improved colon shortening, body weight, the disease activity index (DAI), and histopathological score of DSS-induced colitis mice. DSS significantly increased the levels of cyclooxygenase-(COX-) 2 in colon tissue relative to that of the untreated control group. EBN administered at 100, 200, or 500 mg/(kg·d) reduced COX-2 levels in the DSS-treated mice. In addition, EBN decreased the DSS-induced secretion of the inflammatory cytokine interleukin-6 (IL-6) and chemokine monocyte chemotactic protein-1 (MCP-1). Taken together, these data suggest that B. nivea extract is effective in preventing colitis. PMID:25045208

  15. Protective effects of Punica granatum in experimentally-induced gastric ulcers.

    PubMed

    Alam, Mohd Sarfaraz; Alam, Mohd Aftab; Ahmad, Sayeed; Najmi, Abul Kalam; Asif, Mohd; Jahangir, Tamanna

    2010-11-01

    In the present investigation standardized aqueous methanolic extract of Punica (AMP) was used for its possible ulcer protective activity in wistar rats against different experimental models. Preliminary phytochemical screening of AMP reveals the presence of saponin, tannins, and flavonoids, which may be responsible for its activity. HPTLC finger prints of AMP showed the presence of 12 spots at different (retention factor) rf values. Oral administration of AMP (490 and 980 mg/kg bw) significantly reduced the ulcer lesion index produced by alcohol, indomethacin, and aspirin, at both doses in rats. Further, in pylorus-ligated rats AMP significantly reduces the ulcer lesions, gastric volume, and total acidity. It prevents the ulceration by increasing the pH and mucus secretion in pylorus ligated rats. The present study shows the anti-ulcer activity of AMP in experimentally-induced gastric ulcers. PMID:20846023

  16. Activity of "nonspecific pancreatic carboxylesterase" in rat serum in experimentally induced acute pancreatitis (preliminary results).

    PubMed

    Kálmán, A; Kálmán, Z; Velösy, G; Vargha, G; Vargha, G; Papp, M

    1989-01-01

    The aim of this study was to obtain more information on the serum level of "nonspecific pancreatic carboxylesterase" (PCE) in experimentally induced acute pancreatitis in rats. The effects of caerulein stimulation, hepatic duct ligation, bile-pancreatic duct ligation or the effect of retrograde injection of saline, 5% taurocholate and sunflower oil were investigated. The activity of PCE and amylase was measured in the serum, pancreatic tissue, pancreatic juice and ascitic fluid. The changes in PCE activity were greater (both in directions to increase or decrease) than that of amylase, produced by different experimental procedures. The results confirm the thesis that the serum activity of PCE is a more sensitive diagnostic method than that of amylase to detect the inflammatory process in the pancreas or the effect of obstruction of the pancreatic duct. PMID:2480696

  17. A combined experimental and numerical investigation of roughness induced supersonic boundary layer transition

    NASA Astrophysics Data System (ADS)

    Zhao, Yunfei; Liu, Wei; Xu, Dan; Gang, Dundian; Yi, Shihe

    2016-01-01

    The effect of surface roughness on boundary layer transition is of great importance to hypersonic vehicles. In this paper, both experimental and numerical methods are used to investigate the laminar-turbulent transition of a Mach 3 flat-plate boundary layer induced by isolated roughness element. Good agreements are achieved between experimental data and high-order numerical simulations. It is observed that, with increasing height of roughness, the transition tends to move forward. Two different types of transition mechanisms are found according to the height of the roughness elements. For the smallest roughness height of h=1 mm, the shear layer instability in the wake region appears to be the leading mechanism for transition to turbulence. For two larger roughness elements of h=2 mm and h=4 mm, strong unsteadiness is developed from the upstream separation zone and transition is immediately accomplished, which indicates that the absolute instability in upstream separation zone dominates the transition.

  18. The Effects of Experimentally Induced Low Back Pain on Spine Rotational Stiffness and Local Dynamic Stability.

    PubMed

    Ross, Gwyneth B; Mavor, Matthew; Brown, Stephen H M; Graham, Ryan B

    2015-09-01

    Local dynamic stability, quantified using the maximum finite-time Lyapunov exponent (λ max), and the muscular contributions to spine rotational stiffness can provide pertinent information regarding the neuromuscular control of the spine during movement tasks. The primary goal of the present study was to assess if experimental capsaicin-induced low back pain (LBP) affects spine stability and the neuromuscular control of repetitive trunk movements in a group of healthy participants with no history of LBP. Fourteen healthy males were recruited for this investigation. Each participant was asked to complete three trials (baseline, in pain, and recovery) of 35 cycles of a repetitive trunk flexion/extension task at a rate of 0.25 Hz. Local dynamic stability and the muscular contributions to lumbar spine rotational stiffness were significantly impaired during the LBP trial compared to the baseline trial (p < 0.05); however, there was a trend for these measures to recover after a 1 h rest. This study provides evidence that capsaicin can effectively induce LBP, thereby altering spine rotational stiffness and local dynamic stability. Future research should directly compare the effects capsaicin-induced LBP and intramuscular/intraligamentous induced LBP on these same variables. PMID:25663629

  19. Nigella sativa amliorates inflammation and demyelination in the experimental autoimmune encephalomyelitis-induced Wistar rats

    PubMed Central

    Noor, Neveen A; Fahmy, Heba M; Mohammed, Faten F; Elsayed, Anwar A; Radwan, Nasr M

    2015-01-01

    Multiple sclerosis (MS) is the major, immune-mediated, demyelinating neurodegenerative disease of the central nervous system (CNS). Experimental autoimmune encephalomyelitis (EAE) is a well-established animal model of MS. The aim of the present study was to investigate the protective and ameliorative effects of N. sativa seeds (2.8 g/kg body weight) in EAE-induced Wistar rats. EAE-induced rats were divided into: 1- EAE-induced rats (“EAE” group). 2- “N. sativa + EAE” group received daily oral administration of N. sativa 2 weeks prior EAE induction until the end of the experiment. 3- “EAE + N. sativa” group received daily oral administration of N. sativa after the appearance of first clinical signs until the end of the experiment. All animals were decapitated at the 28th day post EAE-induction. EAE was investigated using histopathological, immunohistochemical and ultrastructural examinations in addition to determination of some oxidative stress parameters in the cerebellum and medulla. N. sativa suppressed inflammation observed in EAE-induced rats. In addition, N. sativa enhanced remyelination in the cerebellum. Moreover, N. sativa reduced the expression of transforming growth factor beta 1 (TGF β1). N. sativa seeds could provide a promising agent effective in both the protection and treatment of EAE. PMID:26261504

  20. Bromocriptine induces parapoptosis as the main type of cell death responsible for experimental pituitary tumor shrinkage

    SciTech Connect

    Palmeri, Claudia Mariela Petiti, Juan Pablo; Valle Sosa, Liliana del; Gutierrez, Silvina; Paul, Ana Lucia de; Mukdsi, Jorge Humberto; Torres, Alicia Ines

    2009-10-01

    Bromocriptine (Bc) produces pituitary tumoral mass regression which induces the cellular death that was classically described as apoptosis. However, recent works have related that other mechanisms of cell death could also be involved in the maintenance of physiological and pathological pituitary homeostasis. The aim of this study was to evaluate and characterize the different types of cell death in the involution induced by Bc in experimental rat pituitary tumors. The current study demonstrated that Bc induced an effective regression of estrogen induced pituitary tumors by a mechanism identified as parapoptosis. This alternative cell death was ultrastructurally recognized by extensive cytoplasmic vacuolization and an increased cell electron density, represented around 25% of the total pituitary cells counted. Furthermore, the results obtained from biochemical assays did not correspond to the criteria of apoptosis or necrosis. We also investigated the participation of p38, ERK1/2 and PKC{delta} in the parapoptotic pathway. An important observation was the significant increase in phosphorylated forms of these MAPKs, the holoenzyme and catalytic fragments of PKC{delta} in nuclear fractions after Bc administration compared to control and estrogen treated rats. Furthermore, the immunolocalization at ultrastructural level of these kinases showed a similar distribution pattern, with a prevalent localization at nuclear level in lactotrophs from Bc treated rats. In summary, we determined that parapoptosis is the predominant cell death type involved in the regression of pituitary tumors in response to Bc treatment, and may cause the activation of PKC{delta}, ERK1/2 and p38.

  1. A proposal for the experimental detection of CSL induced random walk

    PubMed Central

    Bera, Sayantani; Motwani, Bhawna; Singh, Tejinder P.; Ulbricht, Hendrik

    2015-01-01

    Continuous Spontaneous Localization (CSL) is one possible explanation for dynamically induced collapse of the wave-function during a quantum measurement. The collapse is mediated by a stochastic non-linear modification of the Schrödinger equation. A consequence of the CSL mechanism is an extremely tiny violation of energy-momentum conservation, which can, in principle, be detected in the laboratory via the random diffusion of a particle induced by the stochastic collapse mechanism. In a paper in 2003, Collett and Pearle investigated the translational CSL diffusion of a sphere, and the rotational CSL diffusion of a disc, and showed that this effect dominates over the ambient environmental noise at low temperatures and extremely low pressures (about ten-thousandth of a pico-Torr). In the present paper, we revisit their analysis and argue that this stringent condition on pressure can be relaxed, and that the CSL effect can be seen at the pressure of about a pico-Torr. A similar analysis is provided for diffusion produced by gravity-induced decoherence, where the effect is typically much weaker than CSL. We also discuss the CSL induced random displacement of a quantum oscillator. Lastly, we propose possible experimental set-ups justifying that CSL diffusion is indeed measurable with the current technology. PMID:25563619

  2. Nigella sativa amliorates inflammation and demyelination in the experimental autoimmune encephalomyelitis-induced Wistar rats.

    PubMed

    Noor, Neveen A; Fahmy, Heba M; Mohammed, Faten F; Elsayed, Anwar A; Radwan, Nasr M

    2015-01-01

    Multiple sclerosis (MS) is the major, immune-mediated, demyelinating neurodegenerative disease of the central nervous system (CNS). Experimental autoimmune encephalomyelitis (EAE) is a well-established animal model of MS. The aim of the present study was to investigate the protective and ameliorative effects of N. sativa seeds (2.8 g/kg body weight) in EAE-induced Wistar rats. EAE-induced rats were divided into: 1- EAE-induced rats ("EAE" group). 2- "N. sativa + EAE" group received daily oral administration of N. sativa 2 weeks prior EAE induction until the end of the experiment. 3- "EAE + N. sativa" group received daily oral administration of N. sativa after the appearance of first clinical signs until the end of the experiment. All animals were decapitated at the 28th day post EAE-induction. EAE was investigated using histopathological, immunohistochemical and ultrastructural examinations in addition to determination of some oxidative stress parameters in the cerebellum and medulla. N. sativa suppressed inflammation observed in EAE-induced rats. In addition, N. sativa enhanced remyelination in the cerebellum. Moreover, N. sativa reduced the expression of transforming growth factor beta 1 (TGF β1). N. sativa seeds could provide a promising agent effective in both the protection and treatment of EAE. PMID:26261504

  3. Ameliorative potential of fluoxetine/raloxifene combination on experimentally induced breast cancer.

    PubMed

    Kabel, Ahmed M; Elkhoely, Abeer A

    2016-04-01

    Breast cancer is one of the most common types of malignancies in females worldwide. Targeting the estrogen receptors alone with raloxifene (RAL) reduces the incidence of estrogen receptor positive tumors. Fluoxetine (FLX) is one of selective serotonin reuptake inhibitors that was proven to have anticancer properties. Our aim was to detect the effects of RAL/FLX combination on experimentally induced breast cancer. Eighty female Wistar rats were divided into four equal groups: 7,12-Dimethyl Benzanthracene (DMBA) induced breast cancer group, DMBA+RAL, DMBA+FLX and DMBA+RAL+FLX. Tumor volume, tissue malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6) and transforming growth factor beta1 (TGF-β1) were determined in the tumor tissues. Parts of the tumor were subjected to histopathological examination. RAL or FLX alone or in combination induced significant increase in tumor CAT and SOD with significant decrease in tumor volume, tissue MDA, TNF-α, IL-6 and TGF-β1 and alleviated the histopathological and immunohistochemical changes compared to DMBA group. In conclusion, RAL/FLX combination had a better effect than each of RAL or FLX alone against DMBA-induced breast cancer in rats which may represent a new therapeutic modality for management of breast cancer. PMID:26881735

  4. Experimental febrile seizures induce age-dependent structural plasticity and improve memory in mice.

    PubMed

    Tao, K; Ichikawa, J; Matsuki, N; Ikegaya, Y; Koyama, R

    2016-03-24

    Population-based studies have demonstrated that children with a history of febrile seizure (FS) perform better than age-matched controls at hippocampus-dependent memory tasks. Here, we report that FSs induce two distinct structural reorganizations in the hippocampus and bidirectionally modify future learning abilities in an age-dependent manner. Compared with age-matched controls, adult mice that had experienced experimental FSs induced by hyperthermia (HT) on postnatal day 14 (P14-HT) performed better in a cognitive task that requires dentate granule cells (DGCs). The enhanced memory performance correlated with an FS-induced persistent increase in the density of large mossy fiber terminals (LMTs) of the DGCs. The memory enhancement was not observed in mice that had experienced HT-induced seizures at P11 which exhibited abnormally located DGCs in addition to the increased LMT density. The ectopic DGCs of the P11-HT mice were abolished by the diuretic bumetanide, and this pharmacological treatment unveiled the masked memory enhancement. Thus, this work provides a novel basis for age-dependent structural plasticity in which FSs influence future brain function. PMID:26794590

  5. A proposal for the experimental detection of CSL induced random walk.

    PubMed

    Bera, Sayantani; Motwani, Bhawna; Singh, Tejinder P; Ulbricht, Hendrik

    2015-01-01

    Continuous Spontaneous Localization (CSL) is one possible explanation for dynamically induced collapse of the wave-function during a quantum measurement. The collapse is mediated by a stochastic non-linear modification of the Schrödinger equation. A consequence of the CSL mechanism is an extremely tiny violation of energy-momentum conservation, which can, in principle, be detected in the laboratory via the random diffusion of a particle induced by the stochastic collapse mechanism. In a paper in 2003, Collett and Pearle investigated the translational CSL diffusion of a sphere, and the rotational CSL diffusion of a disc, and showed that this effect dominates over the ambient environmental noise at low temperatures and extremely low pressures (about ten-thousandth of a pico-Torr). In the present paper, we revisit their analysis and argue that this stringent condition on pressure can be relaxed, and that the CSL effect can be seen at the pressure of about a pico-Torr. A similar analysis is provided for diffusion produced by gravity-induced decoherence, where the effect is typically much weaker than CSL. We also discuss the CSL induced random displacement of a quantum oscillator. Lastly, we propose possible experimental set-ups justifying that CSL diffusion is indeed measurable with the current technology. PMID:25563619

  6. A proposal for the experimental detection of CSL induced random walk

    NASA Astrophysics Data System (ADS)

    Bera, Sayantani; Motwani, Bhawna; Singh, Tejinder P.; Ulbricht, Hendrik

    2015-01-01

    Continuous Spontaneous Localization (CSL) is one possible explanation for dynamically induced collapse of the wave-function during a quantum measurement. The collapse is mediated by a stochastic non-linear modification of the Schrödinger equation. A consequence of the CSL mechanism is an extremely tiny violation of energy-momentum conservation, which can, in principle, be detected in the laboratory via the random diffusion of a particle induced by the stochastic collapse mechanism. In a paper in 2003, Collett and Pearle investigated the translational CSL diffusion of a sphere, and the rotational CSL diffusion of a disc, and showed that this effect dominates over the ambient environmental noise at low temperatures and extremely low pressures (about ten-thousandth of a pico-Torr). In the present paper, we revisit their analysis and argue that this stringent condition on pressure can be relaxed, and that the CSL effect can be seen at the pressure of about a pico-Torr. A similar analysis is provided for diffusion produced by gravity-induced decoherence, where the effect is typically much weaker than CSL. We also discuss the CSL induced random displacement of a quantum oscillator. Lastly, we propose possible experimental set-ups justifying that CSL diffusion is indeed measurable with the current technology.

  7. Experimental Study of a Single-Coil Induced-Electromotive-Force Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Matthews, Clarence W.; Cuddihy, William F.

    1961-01-01

    An experimental study was made of a single-coil induced-electromotive-force plasma accelerator which used a capacitor discharge for the driving force. A strong shock was observed from the first pulse with a velocity of 10(exp 6) centimeters per second. This shock was followed by three or four discharges which produced plasmoids moving at about 5 x 10(exp 6) centimeters per second. The efficiency of the accelerator was estimated to be about 3 percent in the production of the high-velocity plasmoids. Suggestions are made for the improvement of this type of accelerator.

  8. Experimental Study of the Cross Sections of {alpha}-Particle Induced Reactions on 209Bi

    SciTech Connect

    Hermanne, A.; Tarkanyi, F.; Takacs, S.; Szucs, Z.

    2005-05-24

    Alpha particle induced reactions for generation of 211At used in therapeutic nuclear medicine and possible contaminants were investigated with the stacked foil activation technique on natural bismuth targets up to E{alpha}=39 MeV. Excitation functions for the reactions 209Bi({alpha},2n)211At, 209Bi({alpha},3n)210At, 209Bi({alpha},x) 210Po obtained from direct alpha emission measurements and gamma spectra from decay products are compared with earlier literature values. Thick target yields have been deduced from the experimental cross sections.

  9. Aerobic exercise training without weight loss reduces dyspnea on exertion in obese women.

    PubMed

    Bernhardt, Vipa; Stickford, Jonathon L; Bhammar, Dharini M; Babb, Tony G

    2016-01-15

    Dyspnea on exertion (DOE) is a common symptom in obesity. We investigated whether aerobic exercise training without weight loss could reduce DOE. Twenty-two otherwise healthy obese women participated in a 12-week supervised aerobic exercise training program, exercising 30 min/day at 70-80% heart rate reserve, 4 days/week. Subjects were grouped based on their Ratings of Perceived Breathlessness (RPB) during constant load 60 W cycling: +DOE (n=12, RPB≥4, 37±7 years, 34±4 kg/m(2)) and -DOE (n=10, RPB≤2, 32±6 years, 33±3 kg/m(2)). No significant differences between the groups in body composition, pulmonary function, or cardiorespiratory fitness were observed pre-training. Post-training,peak was improved significantly in both groups (+DOE: 12±7, -DOE: 14±8%). RPB was significantly decreased in the +DOE (4.7±1.0-2.5±1.0) and remained low in the -DOE group (1.2±0.6-1.3±1.0) (interaction p<0.001). The reduction in RPB was not significantly correlated with the improvement in cardiorespiratory fitness. Aerobic exercise training improved cardiorespiratory fitness and DOE and thus appears to be an effective treatment for DOE in obese women. PMID:26593640

  10. Dyspnea and dysphagia from upper airway obstruction after occipitocervical fusion in the pediatric age group.

    PubMed

    Huang, Meng; Gonda, David D; Briceño, Valentina; Lam, Sandi K; Luerssen, Thomas G; Jea, Andrew

    2015-04-01

    Upper airway obstruction resulting from overflexion of the craniocervical junction after occipitocervical fusion is a rare but potentially life-threatening complication and is associated with morbidity. The authors retrospectively reviewed the medical records and diagnostic images of 2 pediatric patients who underwent occipitocervical fusion by the Neuro-Spine Program at Texas Children's Hospital and experienced dyspnea and/or dysphagia from new upper airway obstruction in the postoperative period. Patient demographics, operative data, and preoperative and postoperative occiput-C2 angles were recorded. A review of the literature for similar complications after occipitocervical fusion was performed. A total of 13 cases of prolonged upper airway obstruction after occipitocervical fusion were analyzed. Most of these cases involved adults with rheumatoid arthritis. To the best of the authors' knowledge, there have been no previous reports of prolonged upper airway obstruction in children after an occipitocervical fusion. Fixation of the neck in increased flexion (-18° to -5°) was a common finding among these adult and pediatric cases. The authors' cases involved children with micrognathia and comparatively large tongues, which may predispose the oropharynx to obstruction with even the slightest amount of increased flexion. Close attention to a satisfactory fixation angle (occiput-C2 angle) is necessary to avoid airway obstruction after an occipitocervical fusion. Children with micrognathia are particularly sensitive to changes in flexion at the craniocervical junction after occipitocervical fixation. PMID:25828489

  11. Stethoscope versus point-of-care ultrasound in the differential diagnosis of dyspnea: a randomized trial.

    PubMed

    Özkan, Behzat; Ünlüer, Erden E; Akyol, Pinar Y; Karagöz, Arif; Bayata, Mehmet S; Akoğlu, Haldun; Oyar, Orhan; Dalli, Ayşe; Topal, Fatih E

    2015-12-01

    We aimed to determine the accuracies of point-of-care ultrasound (PoCUS) and stethoscopes as part of the physical examinations of patients with dyspnea. Three emergency medicine specialists in each of two groups of ultrasound and stethoscope performers underwent didactic and hands-on training on PoCUS and stethoscope usage. All the patients enrolled were randomized to one of two predetermined PoCUS or stethoscope groups. The diagnostic performance of ultrasonography was higher than that of the stethoscope in the diagnoses of heart failure (90 vs. 86%, 1.00 vs. 0.89, and 5.00 vs. 4.92, respectively) and pneumonia (90 vs. 86.7%, 0.75 vs. 0.73, and 16.50 vs. 13.82, respectively). No significant differences were observed in the utility parameters of these modalities in these diagnoses. Although some authors argue that it is time to abandon the 'archaic tools' of past centuries, we believe that it is too early to discontinue the use of the stethoscope. PMID:25715019

  12. [Case of dyspnea due to toilet cleaner containing nitric acid for household use].

    PubMed

    Yanagawa, Youichi; Matsukawa, Takehisa; Yokoyama, Kazuhito; Hirano, Yohei; Ri, Tetsunari; Aihara, Koichiro; Iba, Toshiaki; Tanaka, Hiroshi

    2013-09-01

    A 40-year-old male tried to clean a urinal at his home storing 900 mL of a toilet cleaner containing 9.8% nitric acid to remove calcium deposit, and clean the toilet floor for twenty minutes. Immediately after using the cleaner, he experienced eye irritation. He washed out the toilet cleaner. However, he thereafter experienced dyspnea, a compressive sensation in his chest, and chest and back pain about 40 minutes after the cleaning the toilet. He monitored his symptoms overnight and found them to gradually improve. However, the symptoms still remained the next morning and therefore he came to our department on foot. He had no particular past or family history. On arrival, his physiological findings and chest computed tomography scan were negative for any abnormalities. His arterial blood gas analysis revealed a mild abnormality of oxygenation. Observation without any drugs revealed that a complete remission of his symptoms occurred after approximately 4 weeks. Based on the results of the experiments, contact with the mucosal membrane and nitric acid gas produced by any accidentally coexisting metals or contact with moisture, including nitric acid produced by a reaction between CaCO3 and cleaner, may have been the mechanism of occurrence for the symptoms observed in this case. This is the first reported case of nitric acid poisoning due to the use of a toilet cleanser intended for household use. PMID:24224389

  13. A Computational and Experimental Study of Nonlinear Aspects of Induced Drag

    NASA Technical Reports Server (NTRS)

    Smith, Stephen C.

    1996-01-01

    performance of the split-tip wing was also investigated by wing tunnel experiments. Induced drag was determined from force measurements by subtracting the estimated viscous drag, and from an analytical drag-decomposition method using a wake survey. The experimental results confirm the computational prediction.

  14. TNF-α Involvement in Insulin Resistance Induced by Experimental Scorpion Envenomation

    PubMed Central

    Ait-Lounis, Aouatef; Laraba-Djebari, Fatima

    2012-01-01

    Background Scorpion venom induces systemic inflammation characterized by an increase in cytokine release and chemokine production. There have been few experimental studies assessing the effects of scorpion venom on adipose tissue function in vivo. Methodology/Principal Findings To study the adipose tissue inflammation (ATI) induced by Androctonus australis hector (Aah) venom and to assess possible mechanisms of ATI, mice (n = 6, aged 1 month) were injected with Aah (0.45 mg/kg), toxic fraction of Aah (FTox-G50; 0.2 mg/kg) or saline solution (control). Inflammatory responses were evaluated by ELISA and cell sorting analyses in adipose tissue 45 minutes and 24 hours after injection. Quantitative real-time PCR was used to assess the regulation of genes implicated in glucose uptake. The titers of selected inflammatory cytokines (IL-1β, IL-6 and TNF-α) were also determined in sera and in insulin target tissues. The serum concentration of IL-1β rose 45 minutes after envenomation and returned to basal level after 24 hours. The pathophysiological effects of the venom after 24 hours mainly involved M1-proinflammatory macrophage infiltration in adipose tissue combined with high titers of IL-1β, IL-6 and TNF-α. Indeed, TNF-α was strongly induced in both adipose tissue and skeletal muscle. We studied the effects of Aah venom on genes implicated in insulin-stimulated glucose uptake. Insulin induced a significant increase in the expression of the mRNAs for hexokinase 2 and phosphatidylinositol 3-kinase in both skeletal muscle and adipose tissue in control mice; this upregulation was completely abolished after 24 hours in mice envenomed with Aah or FTox-G50. Conclusions/Significance Our findings suggest that Aah venom induces insulin resistance by mechanisms involving TNF-α-dependent Map4k4 kinase activation in the adipose tissue. PMID:22816003

  15. RNase L contributes to experimentally induced type I diabetes onset in mice

    PubMed Central

    Zeng, Chun; Yi, Xin; Zipris, Danny; Liu, Hongli; Zhang, Lin; Zheng, Qiaoyun; Krishnamurthy, Malathi; Jin, Ge; Zhou, Aimin

    2014-01-01

    The cause of type I diabetes continues to be a focus of investigation. Studies have revealed that interferon (IFN)-α in pancreatic islets after viral infection or treatment with double-stranded RNA (dsRNA), a mimic of viral infection, is associated with the onset of type I diabetes. However, how IFN-α contributes to the onset of type I diabetes is obscure. In this study, we found that 2-5A dependent RNase L (RNase L), an IFN-α-inducible enzyme that functions in the antiviral and antiproliferative activities of IFN, played an important role in dsRNA-induced onset of type I diabetes. By using RNase L deficient, rat insulin promoter (RIP)-B7.1 transgenic mice which are more vulnerable to environmental harmful factors such as viral infection, we demonstrated that deficiency of RNase L in mice resulted in a significant delay of diabetes onset induced by polyinosinic:polycytidylic acid (poly I:C), a type of synthetic dsRNA, and streptozotocin (STZ), a drug which can artificially induce type I-like diabetes in experimental animals. Immunohistochemical staining showed that the population of infiltrated CD8+ T-cells was remarkably reduced in the islets of RNase L deficient mice, suggesting that RNase L may contribute to type I diabetes onset through regulating immune responses. Furthermore, RNase L was responsible for the expression of certain proinflammatory genes in the pancreas in induced conditions. Our findings provide new insight into the molecular mechanism underlying β-cells destruction and may suggest novel therapeutic strategies for treatment and prevention of the disease based on the selective regulation and inhibition of RNase L. PMID:25287058

  16. [Characterization of an experimental model of monosodium- glutamate-induced convulsions in the amphibian Bufo spp].

    PubMed

    Alfaro, F; Blas, O; Gutiérrez-Padilla, R; Feria-Velasco, A

    1990-01-01

    In previous reports, Feria-Velasco et al. characterized an experimental model of convulsions in rats induced by monosodium glutamate (MSG) with evaluation of the motor behavior and neurochemical parameters. In the present work, MSG injected in toads (Bufo spp) reproduced the model of convulsions with some peculiarities. The electrocorticographic recordings in toads after MSG injection were similar to those obtained in rats after administration of convulsant agents. Most of the toads injected with MSG (81.8%) showed convulsions preceded by an episode of stereotyped movements and signs of hyperexcitability. Latency for convulsions and frequency of convulsive episodes were similar to what has been reported in rats injected with MSG. However, the duration of convulsive period was larger than that seen in rats, and no deaths were recorded in toads. The peculiar feature of amphibia regarding their cerebral structures and their blood-brain barrier (BBB) make the amphibian model, an interesting and valuable one in studying experimentally induced convulsions, as well as the role of BBB in these phenomena. PMID:1669233

  17. Experimental investigation of flow induced dust acoustic shock waves in a complex plasma

    NASA Astrophysics Data System (ADS)

    Jaiswal, S.; Bandyopadhyay, P.; Sen, A.

    2016-08-01

    We report on experimental observations of flow induced large amplitude dust-acoustic shock waves in a complex plasma. The experiments have been carried out in a Π shaped direct current glow discharge experimental device using kaolin particles as the dust component in a background of Argon plasma. A strong supersonic flow of the dust fluid is induced by adjusting the pumping speed and neutral gas flow into the device. An isolated copper wire mounted on the cathode acts as a potential barrier to the flow of dust particles. A sudden change in the gas flow rate is used to trigger the onset of high velocity dust acoustic shocks whose dynamics are captured by fast video pictures of the evolving structures. The physical characteristics of these shocks are delineated through a parametric scan of their dynamical properties over a range of flow speeds and potential hill heights. The observed evolution of the shock waves and their propagation characteristics are found to compare well with model numerical results based on a modified Korteweg-de-Vries-Burgers type equation.

  18. Brugia malayi abundant larval transcript 2 protein treatment attenuates experimentally-induced colitis in mice.

    PubMed

    Khatri, Vishal; Amdare, Nitin; Yadav, Ravi Shankar; Tarnekar, Aaditya; Goswami, Kalyan; Reddy, Maryada Venkata Rami

    2015-11-01

    Helminths are known to modulate host's immunity by suppressing host protective pro-inflammatory responses. Such immunomodulatory effects have been experimentally shown to have therapeutic implications in immune mediated disorders. In the present study, we have explored a filarial protein i.e. Brugia malayi recombinant abundant larval transcript 2 (rBmALT2) for its therapeutic effect in dextran sodium sulfate (DSS) induced colitis in mouse model. The immunomodulatory activity of rBmALT-2 was initially confirmed by demonstrating that it suppressed the lipopolysaccharide (LPS) induced nitric oxide synthesis and down-regulated the expression of pro-inflammatory cytokines in vitro by peritoneal exudate cells of mice. Treatment with rBmALT2 reduced severity of colitis associated with significant reduction in weight loss, disease activity, colon damage, mucosal edema and histopathological score including myeloperoxidase activity in colon tissues. rBmALT2 was comparatively more effective in attenuation of colitis when used in the preventive mode than when used for curative purpose. The therapeutic effect of rBmALT2 was found to be associated with downregulation of IFN-γ, IL-6, IL-17 and upregulation of IL-10 cytokines. These results provide strong experimental evidence that BmALT2 could be a potential alternative therapeutic agent in colitis. PMID:26669016

  19. Experimental Gingivitis Induces Systemic Inflammatory Markers in Young Healthy Individuals: A Single-Subject Interventional Study

    PubMed Central

    Luchtefeld, Maren; Heuer, Wieland; Schuett, Harald; Divchev, Dimitar; Scherer, Ralph; Schmitz-Streit, Ruth; Langfeldt, Daniela; Stumpp, Nico; Staufenbiel, Ingmar

    2013-01-01

    Objectives We here investigated whether experimental gingivitis enhances systemic markers of inflammation which are also known as surrogate markers of atherosclerotic plaque development. Background Gingivitis is a low-level oral infection induced by bacterial deposits with a high prevalence within Western populations. A potential link between the more severe oral disease periodontitis and cardiovascular disease has already been shown. Methods 37 non-smoking young volunteers with no inflammatory disease or any cardiovascular risk factors participated in this single-subject interventional study with an intra-individual control. Intentionally experimental oral inflammation was induced by the interruption of oral hygiene for 21 days, followed by a 21-days resolving phase after reinitiation of oral hygiene. Primary outcome measures at baseline, day 21 and 42 were concentrations of hsCRP, IL-6, and MCP-1, as well as adhesion capacity and oxLDL uptake of isolated blood monocytes. Results The partial cessation of oral hygiene procedures was followed by the significant increase of gingival bleeding (34.0%, P<0.0001). This local inflammation was associated with a systemic increase in hsCRP (0.24 mg/L, P = 0.038), IL-6 (12.52 ng/L, P = 0.0002) and MCP-1 (9.10 ng/l, P = 0.124) in peripheral blood samples between baseline and day 21, which decreased at day 42. Monocytes showed an enhanced adherence to endothelial cells and increased foam cell formation after oxLDL uptake (P<0.050) at day 21 of gingivitis. Conclusions Bacterial-induced gingival low-level inflammation induced a systemic increase in inflammatory markers. Dental hygiene almost completely reversed this experimental inflammatory process, suggesting that appropriate dental prophylaxis may also limit systemic markers of inflammation in subjects with natural gingivitis. International Clinical Trials Register Platform of the World Health Organization, registry number: DRKS00003366, URL: http

  20. Experimental tonic hand pain modulates the corticospinal plasticity induced by a subsequent hand deafferentation.

    PubMed

    Mavromatis, N; Gagné, M; Voisin, J I A V; Reilly, K T; Mercier, C

    2016-08-25

    Sensorimotor reorganization is believed to play an important role in the development and maintenance of phantom limb pain, but pain itself might modulate sensorimotor plasticity induced by deafferentation. Clinical and basic research support this idea, as pain prior to amputation increases the risk of developing post-amputation pain. The aim of this study was to examine the influence of experimental tonic cutaneous hand pain on the plasticity induced by temporary ischemic hand deafferentation. Sixteen healthy subjects participated in two experimental sessions (Pain, No Pain) in which transcranial magnetic stimulation was used to assess corticospinal excitability in two forearm muscles (flexor carpi radialis and flexor digitorum superficialis) before (T0, T10, T20, and T40) and after (T60 and T75) inflation of a cuff around the wrist. The cuff was inflated at T45 in both sessions and in the Pain session capsaicin cream was applied on the dorsum of the hand at T5. Corticospinal excitability was significantly greater during the Post-inflation phase (p=0.002) and increased similarly in both muscles (p=0.861). Importantly, the excitability increase in the Post-inflation phase was greater for the Pain than the No-Pain condition (p=0.006). Post-hoc analyses revealed a significant difference between the two conditions during the Post-inflation phase (p=0.030) but no difference during the Pre-inflation phase (p=0.601). In other words, the corticospinal facilitation was greater when pain was present prior to cuff inflation. These results indicate that pain can modulate the plasticity induced by another event, and could partially explain the sensorimotor reorganization often reported in chronic pain populations. PMID:27291642

  1. Assessing potential abiotic and biotic complications of crayfish-induced gravel transport in experimental streams

    NASA Astrophysics Data System (ADS)

    Statzner, Bernhard; Peltret, Odile

    2006-03-01

    Biogeomorphology adds the element "biological dynamics" (of populations or communities) to chemical and physical geomorphic factors and thus complicates the framework of geomorphic processes. Such biological complications of the animal-induced transport of solids in streams should be particularly important in crayfish, as crayfish affect this transport through their overall activity and intraspecific aggression levels, which could be modified by shelter availability or the establishment of dominance hierarchies among individuals not knowing each other. Using experimental streams, we tested these hypotheses by measuring how shelter availability or residential crayfish group invasion by unknown individuals affected the impact of the crayfish Orconectes limosus on the (i) transport of gravel at baseflow (during 12 experimental days); (ii) sediment surface characteristics (after 12 days); and (iii) critical shear stress causing incipient gravel motion during simulated floods (after 12 days). The two potentially important factors shelter availability or residential group invasion negligibly affected the crayfish impact on gravel sediments, suggesting that habitat unfamiliarity (a third potentially important factor affecting crayfish activity) should increase the crayfish-induced sediment transport. Because habitat unfamiliarity is associated with sporadic long-distance migrations of a few crayfish individuals, this third factor should play a minor role in real streams, where crayfish biomass should be a key factor in relations with crayfish effects on sediments. Therefore, we combined the results of this study with those of previous crayfish experiments to assess how crayfish biomass could serve in modelling the gravel transport. Crayfish biomass explained 47% of the variability in the baseflow gravel transport and, in combination with the coefficient of variation of the bed elevation and algal cover, 72% of the variability in the critical gravel shear stress. These

  2. Strong protection induced by an experimental DIVA subunit vaccine against bluetongue virus serotype 8 in cattle.

    PubMed

    Anderson, Jenna; Hägglund, Sara; Bréard, Emmanuel; Riou, Mickaël; Zohari, Siamak; Comtet, Loic; Olofson, Ann-Sophie; Gélineau, Robert; Martin, Guillaume; Elvander, Marianne; Blomqvist, Gunilla; Zientara, Stéphan; Valarcher, Jean Francois

    2014-11-20

    Bluetongue virus (BTV) infections in ruminants pose a permanent agricultural threat since new serotypes are constantly emerging in new locations. Clinical disease is mainly observed in sheep, but cattle were unusually affected during an outbreak of BTV seroype 8 (BTV-8) in Europe. We previously developed an experimental vaccine based on recombinant viral protein 2 (VP2) of BTV-8 and non-structural proteins 1 (NS1) and NS2 of BTV-2, mixed with an immunostimulating complex (ISCOM)-matrix adjuvant. We demonstrated that bovine immune responses induced by this vaccine were as good or superior to those induced by a classic commercial inactivated vaccine. In this study, we evaluated the protective efficacy of the experimental vaccine in cattle and, based on the detection of VP7 antibodies, assessed its DIVA compliancy following virus challenge. Two groups of BTV-seronegative calves were subcutaneously immunized twice at a 3-week interval with the subunit vaccine (n=6) or with adjuvant alone (n=6). Following BTV-8 challenge 3 weeks after second immunization, controls developed viremia and fever associated with other mild clinical signs of bluetongue disease, whereas vaccinated animals were clinically and virologically protected. The vaccine-induced protection was likely mediated by high virus-neutralizing antibody titers directed against VP2 and perhaps by cellular responses to NS1 and NS2. T lymphocyte responses were cross-reactive between BTV-2 and BTV-8, suggesting that NS1 and NS2 may provide the basis of an adaptable vaccine that can be varied by using VP2 of different serotypes. The detection of different levels of VP7 antibodies in vaccinated animals and controls after challenge suggested a compliancy between the vaccine and the DIVA companion test. This BTV subunit vaccine is a promising candidate that should be further evaluated and developed to protect against different serotypes. PMID:25312275

  3. Time-Dependent Progression of Demyelination and Axonal Pathology in MP4-Induced Experimental Autoimmune Encephalomyelitis

    PubMed Central

    Stormanns, Eva R.; Recks, Mascha S.; Kuerten, Stefanie

    2015-01-01

    Background Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) characterized by inflammation, demyelination and axonal pathology. Myelin basic protein/proteolipid protein (MBP-PLP) fusion protein MP4 is capable of inducing chronic experimental autoimmune encephalomyelitis (EAE) in susceptible mouse strains mirroring diverse histopathological and immunological hallmarks of MS. Limited availability of human tissue underscores the importance of animal models to study the pathology of MS. Methods Twenty-two female C57BL/6 (B6) mice were immunized with MP4 and the clinical development of experimental autoimmune encephalomyelitis (EAE) was observed. Methylene blue-stained semi-thin and ultra-thin sections of the lumbar spinal cord were assessed at the peak of acute EAE, three months (chronic EAE) and six months after onset of EAE (long-term EAE). The extent of lesional area and inflammation were analyzed in semi-thin sections on a light microscopic level. The magnitude of demyelination and axonal damage were determined using electron microscopy. Emphasis was put on the ventrolateral tract (VLT) of the spinal cord. Results B6 mice demonstrated increasing demyelination and severe axonal pathology in the course of MP4-induced EAE. In addition, mitochondrial swelling and a decrease in the nearest neighbor neurofilament distance (NNND) as early signs of axonal damage were evident with the onset of EAE. In semi-thin sections we observed the maximum of lesional area in the chronic state of EAE while inflammation was found to a similar extent in acute and chronic EAE. In contrast to the well-established myelin oligodendrocyte glycoprotein (MOG) model, disease stages of MP4-induced EAE could not be distinguished by assessing the extent of parenchymal edema or the grade of inflammation. Conclusions Our results complement our previous ultrastructural studies of B6 EAE models and suggest that B6 mice immunized with different antigens constitute

  4. Numerical and experimental studies of drying and shrinkage induced microcracking in concrete

    NASA Astrophysics Data System (ADS)

    Jankovic, D.

    2007-12-01

    The aim of this research is to investigate moisture flow in cement paste and Interface Transition Zone, around aggregate, as well as associated shrinkage induced strains, and subsequent microcracking. Two coupled methods are used: numerical simulations and experiments. The moisture flow is numerically simulated by Lattice Gas Automata, while drying experiments are performed in Environmental Scanning Electron Microscope (ESEM) in order to determine drying deformations and shrinkage coefficient. The moisture movement simulation by Lattice Gas Automata, a type of cellular automata, involves different drying collision rules, which results in different density (moisture content) at each node. Special attention is given to the effect of the presence of aggregate particles on the moisture flow in concrete, which are considered rigid obstacles. The shrinkage deformation is considered a linear function of the moisture content if the relative humidity, RH does not exceed 40%. The calculated moisture gradient from the numerical analysis and an assumed shrinkage coefficient are used to calculate drying shrinkage induced strains and stresses using the basic equations. To determine the drying shrinkage coefficient for the RH range 100% to 20%, new experimental techniques of drying in ESEM are used. Small paste samples are cast in a specially developed mould with 2 mm thickness and afterwards carefully grounded and polished to a thickness of required 1 mm. The used variables in the tests are: various cement types, w/c ratio, sample age and curing conditions. Drying shrinkage displacements and strains are determined in order to calculate the drying shrinkage coefficient. These experimentally obtained values of the coefficient are compared with the literature data and used in numerical simulations of shrinkage induced strains, stresses and cracking in drying concrete.

  5. Numerical and experimental investigation of natural flow-induced vibrations of flexible hydrofoils

    NASA Astrophysics Data System (ADS)

    Chae, Eun Jung; Akcabay, Deniz Tolga; Lelong, Alexandra; Astolfi, Jacques Andre; Young, Yin Lu

    2016-07-01

    The objective of this work is to present combined numerical and experimental studies of natural flow-induced vibrations of flexible hydrofoils. The focus is on identifying the dependence of the foil's vibration frequencies and damping characteristics on the inflow velocity, angle of attack, and solid-to-fluid added mass ratio. Experimental results are shown for a cantilevered polyacetate (POM) hydrofoil tested in the cavitation tunnel at the French Naval Academy Research Institute (IRENav). The foil is observed to primarily behave as a chordwise rigid body and undergoes spanwise bending and twisting deformations, and the flow is observed to be effectively two-dimensional (2D) because of the strong lift retention at the free tip caused by a small gap with a thickness less than the wall boundary layer. Hence, the viscous fluid-structure interaction (FSI) model is formulated by coupling a 2D unsteady Reynolds-averaged Navier-Stokes (URANS) model with a two degree-of-freedom (2-DOF) model representing the spanwise tip bending and twisting deformations. Good agreements were observed between viscous FSI predictions and experimental measurements of natural flow-induced vibrations in fully turbulent and attached flow conditions. The foil vibrations were found to be dominated by the natural frequencies in absence of large scale vortex shedding due to flow separation. The natural frequencies and fluid damping coefficients were found to vary with velocity, angle of attack, and solid-to-fluid added mass ratio. In addition, the numerical results showed that the in-water to in-air natural frequency ratios decreased rapidly, and the fluid damping coefficients increased rapidly, as the solid-to-fluid added mass ratio decreases. Uncoupled mode (UM) linear potential theory was found to significantly over-predict the fluid damping for cases of lightweight flexible hydrofoils, and this over-prediction increased with higher velocity and lower solid-to-fluid added mass ratio.

  6. Kainic Acid-Induced Excitotoxicity Experimental Model: Protective Merits of Natural Products and Plant Extracts

    PubMed Central

    Mohd Sairazi, Nur Shafika; Sirajudeen, K. N. S.; Asari, Mohd Asnizam; Muzaimi, Mustapha; Mummedy, Swamy; Sulaiman, Siti Amrah

    2015-01-01

    Excitotoxicity is well recognized as a major pathological process of neuronal death in neurodegenerative diseases involving the central nervous system (CNS). In the animal models of neurodegeneration, excitotoxicity is commonly induced experimentally by chemical convulsants, particularly kainic acid (KA). KA-induced excitotoxicity in rodent models has been shown to result in seizures, behavioral changes, oxidative stress, glial activation, inflammatory mediator production, endoplasmic reticulum stress, mitochondrial dysfunction, and selective neurodegeneration in the brain upon KA administration. Recently, there is an emerging trend to search for natural sources to combat against excitotoxicity-associated neurodegenerative diseases. Natural products and plant extracts had attracted a considerable amount of attention because of their reported beneficial effects on the CNS, particularly their neuroprotective effect against excitotoxicity. They provide significant reduction and/or protection against the development and progression of acute and chronic neurodegeneration. This indicates that natural products and plants extracts may be useful in protecting against excitotoxicity-associated neurodegeneration. Thus, targeting of multiple pathways simultaneously may be the strategy to maximize the neuroprotection effect. This review summarizes the mechanisms involved in KA-induced excitotoxicity and attempts to collate the various researches related to the protective effect of natural products and plant extracts in the KA model of neurodegeneration. PMID:26793262

  7. An experimental setup to characterize MR switched gradient-induced potentials.

    PubMed

    Fokapu, Odette; El-Tatar, Aziz

    2013-06-01

    We have developed an experimental setup as an in vitro research tool for studying the contamination of electrophysiological signals (EPS) by MRI environment; particularly, when due to the switched gradient-induced potentials. The system is composed of: 1) a MRI compatible module for the transmission of the EPS into the MRI tunnel, 2) a gelatin-based tissue-mimicking phantom, placed inside the tunnel, in which EPS is injected, 3) a detection module composed of a five input channel MRI compatible transmitter placed inside the tunnel, allowing an on-site pre-amplification of the bio-potentials and their transmission, via an optical fiber cable, to a four filtered output per channel receiver (350 Hz, 160 Hz, 80 Hz, and 40 Hz, for a total of 20 channels) placed in the control room, and 4) a signal processing algorithm used to analyze the generated induced potentials. A set of tests were performed to validate the electronic performances of the setup. We also present in this work an interesting application of the setup, i.e., the acquisition and analysis of the induced potentials with respect of the slice orientation for a given MRI sequence. Significant modifications of the time and frequency characteristics were observed with respect to axial, coronal or sagittal orientations. PMID:23853335

  8. [Protective effects of S-adenosylmethionine against CCl4 - and ethanol-induced experimental hepatic fibrosis].

    PubMed

    Zhang, F; Gu, J-X; Zou, X-P; Zhuge, Y-Z

    2016-01-01

    In this study the effects of S-adenosylmethionine (SAM) on experimental hepatic fibrotic rats induced by carbon tetrachloride (CCl(4)) and ethanol and the relevant potential mechanisms were explored. Hepatic fibrotic rat models were established with CCl(4) diluted in olive oil being drunk with 10% ethanol in water. SAM was used both for prevention and treatment. Histological evaluation was carried out by hematoxylin-eosin (HE) and Masson staining of hepatic samples. Serum biochemical assays showed that alanine aminotransferase (ALT) was increased and albumin (ALB) was decreased by CCl(4) and ethanol, and both effects were suppressed by preventing and treating use of SAM. The model control rats got significantly higher scores in fatty degeneration, lobular inflammation, and hepatocyte ballooning. A significant improvement was observed in the SAM-prevented rats and SAM-treated rats, which was consistent with the change of fibrosis scoring in each group. Smad3 was induced by CCl(4) and ethanol in the model control group, which was significantly down regulated by SAM. SAM reduced both total Smad3 and phospho-Smad3 in vitro. SAM had a protective effect on hepatic fibrosis in rats induced by CCl(4) combined with ethanol and the down-regulation of activity and expression of Smad3 were involved in the potential mechanisms. PMID:27239849

  9. Evaluation of anti-urolithiatic activity of Pashanabhedadi Ghrita against experimentally induced renal calculi in rats

    PubMed Central

    Gupta, Sanjay Kumar; Baghel, Madhav Singh; Bhuyan, Chaturbhuja; Ravishankar, B.; Ashok, B. K.; Patil, Panchakshari D.

    2012-01-01

    Population in an industrialized world is afflicted by urinary stone disease. Kidney stones are common in all kinds of urolithiasis. One distinguished formulation mentioned by Sushruta for management of Ashmari (urolithiasis) is Pashanabhedadi Ghrita (PBG), which is in clinical practice since centuries. Validation of drug is the requirement of time through the experimental study. In this study, trial of PBG has been made against ammonium oxalate rich diet and gentamicin injection induced renal calculi in albino rats. The calculi were induced by gentamicin injection and ammonium oxalate rich diet. Test drug was administered concomitantly in the dose of 900 mg/kg for 15 consecutive days. Rats were sacrificed on the 16th day. Parameters like kidney weight, serum biochemical, kidney tissue and histopathology of kidney were studied. Concomitant treatment of PBG attenuates blood biochemical parameters non-significantly, where as it significantly attenuated lipid peroxidation and enhanced glutathione and glutathione peroxidase activities. It also decreased crystal deposition markedly into the renal tubules in number as well as size and prevented damage to the renal tubules. The findings showed that PBG is having significant anti-urolithiatic activities against ammonium oxalate rich diet plus gentamicine injection induced urolithiasis in rats. PMID:23723654

  10. Experimental Gestational Diabetes Mellitus Induces Blunted Vasoconstriction and Functional Changes in the Rat Aorta

    PubMed Central

    Tufiño, Cecilia; Villanueva-López, Cleva; Ibarra-Barajas, Maximiliano; Bracho-Valdés, Ismael; Bobadilla-Lugo, Rosa Amalia

    2014-01-01

    Diabetic conditions increase vascular reactivity to angiotensin II in several studies but there are scarce reports on cardiovascular effects of hypercaloric diet (HD) induced gestational diabetes mellitus (GDM), so the objective of this work was to determine the effects of HD induced GDM on vascular responses. Angiotensin II as well as phenylephrine induced vascular contraction was tested in isolated aorta rings with and without endothelium from rats fed for 7 weeks (4 before and 3 weeks during pregnancy) with standard (SD) or hypercaloric (HD) diet. Also, protein expression of AT1R, AT2R, COX-1, COX-2, NOS-1, and NOS-3 and plasma glucose, insulin, and angiotensin II levels were measured. GDM impaired vasoconstrictor response (P < 0.05 versus SD) in intact (e+) but not in endothelium-free (e−) vessels. Losartan reduced GDM but not SD e− vasoconstriction (P < 0.01 versus SD). AT1R, AT2R, and COX-1 and COX-2 protein expression were significantly increased in GDM vessels (P < 0.05 versus SD). Results suggest an increased participation of endothelium vasodilator mediators, probably prostaglandins, as well as of AT2 vasodilator receptors as a compensatory mechanism for vasoconstrictor changes generated by experimental GDM. Considering the short term of rat pregnancy findings can reflect early stage GDM adaptations. PMID:25610861

  11. Interleukin 1-induced augmentation of experimental metastases from a human melanoma in nude mice

    SciTech Connect

    Giavazzi, R.; Garofalo, A.; Bani, M.R.; Abbate, M.; Ghezzi, P.; Boraschi, D.; Mantovani, A.; Dejana, E. )

    1990-08-01

    This study has examined the effect of the cytokine interleukin 1 (IL-1) on metastasis formation by the human melanoma A375M in nude mice. We have found that human recombinant IL-1 beta (a single injection greater than 0.01 micrograms per mouse i.v. given before tumor cells) induced an augmentation of experimental lung metastases from the A375M tumor cells in nude mice. This effect was rapidly induced and reversible within 24 h after IL-1 injection. A similar effect was induced by human recombinant IL-1 alpha and human recombinant tumor necrosis factor, but not by human recombinant interleukin 6. 5-(125I)odo-2'-deoxyuridine-radiolabeled A375M tumor cells injected i.v. remained at a higher level in the lungs of nude mice receiving IL-1 than in control mice. In addition, IL-1 injected 1 h, but not 24 h, after tumor cells enhanced lung colonization as well, thus suggesting an effect of IL-1 on the vascular transit of tumor cells. These findings may explain the observation of enhanced secondary localization of tumor cells at inflammatory sites and suggest that modulation of secondary spread should be carefully considered when assessing the ability of this cytokine to complement cytoreductive therapies.

  12. Fumigaclavine C ameliorates dextran sulfate sodium-induced murine experimental colitis via NLRP3 inflammasome inhibition.

    PubMed

    Guo, Wenjie; Hu, Shasha; Elgehama, Ahmed; Shao, Fenli; Ren, Ren; Liu, Wen; Zhang, Wenjing; Wang, Xinlei; Tan, Renxiang; Xu, Qiang; Sun, Yang; Jiao, Ruihua

    2015-10-01

    In the present study, the effect of Fumigaclavine C, a fungal metabolite, on murine experimental colitis induced by dextran sulfate sodium (DSS) and its possible mechanism were examined in vivo and vitro. Oral administration of Fumigaclavine C dose-dependently attenuated the loss of body weight and shortening of colon length induced by DSS. The disease activity index, histopathologic scores of musco was also significantly reduced by Fumigaclavine C treatment. Protein and mRNA levels of DSS-induced pro-inflammatory cytokines in colon, including TNF-α, IL-1β and IL-17A, were markedly suppressed by Fumigaclavine C. At the same time, decreased activation of caspase-1 in peritoneal macrophages was detected in Fumigaclavine C -treated mice which suggested that the NLRP3 inflammasome activation was suppressed. Furthermore, in the LPS plus ATP cell model, we found that Fumigaclavine C dose-dependent inhibited IL-1β release and caspase-1 activation. Taken together, our results demonstrate the ability of Fumigaclavine C to inhibit NLRP3 inflammasome activation and give some evidence for its potential use in the treatment of inflammatory bowel diseases. PMID:26320672

  13. Toxoplasma gondii Upregulates Interleukin-12 To Prevent Plasmodium berghei-Induced Experimental Cerebral Malaria

    PubMed Central

    Settles, Erik W.; Moser, Lindsey A.; Harris, Tajie H.

    2014-01-01

    A chronic infection with the parasite Toxoplasma gondii has previously been shown to protect mice against subsequent viral, bacterial, or protozoal infections. Here we have shown that a chronic T. gondii infection can prevent Plasmodium berghei ANKA-induced experimental cerebral malaria (ECM) in C57BL/6 mice. Treatment with soluble T. gondii antigens (STAg) reduced parasite sequestration and T cell infiltration in the brains of P. berghei-infected mice. Administration of STAg also preserved blood-brain barrier function, reduced ECM symptoms, and significantly decreased mortality. STAg treatment 24 h post-P. berghei infection led to a rapid increase in serum levels of interleukin 12 (IL-12) and gamma interferon (IFN-γ). By 5 days after P. berghei infection, STAg-treated mice had reduced IFN-γ levels compared to those of mock-treated mice, suggesting that reductions in IFN-γ at the time of ECM onset protected against lethality. Using IL-10- and IL-12βR-deficient mice, we found that STAg-induced protection from ECM is IL-10 independent but IL-12 dependent. Treatment of P. berghei-infected mice with recombinant IL-12 significantly decreased parasitemia and mortality. These data suggest that IL-12, either induced by STAg or injected as a recombinant protein, mediates protection from ECM-associated pathology potentially through early induction of IFN-γ and reduction in parasitemia. These results highlight the importance of early IL-12 induction in protection against ECM. PMID:24396042

  14. Analytical and Experimental Characterization of Gravity Induced Deformations In Subscale Gossamer Structures

    NASA Technical Reports Server (NTRS)

    Johnston, John D.; Blandino, Joseph R.; McEvoy, Kiley C.

    2004-01-01

    The development of gossamer space structures such as solar sails and sunshields presents many challenges due to their large size and extreme flexibility. The post-deployment structural geometry exhibited during ground testing may significantly depart from the in-space configuration due to the presence of gravity-induced deformations (gravity sag) of lightly preloaded membranes. This paper describes a study carried out to characterize gravity sag in two subscale gossamer structures: a single quadrant from a 2 m, 4 quadrant square solar sail and a 1.7 m membrane layer from a multi-layer sunshield The behavior of the test articles was studied over a range of preloads and in several orientations with respect to gravity. An experimental study was carried out to measure the global surface profiles using photogrammetry, and nonlinear finite element analysis was used to predict the behavior of the test articles. Comparison of measured and predicted surface profiles shows that the finite dement analysis qualitatively predicts deformed shapes comparable to those observed in the laboratory. Quantitatively, finite element analysis predictions for peak gravity-induced deformations in both test articles were within 10% of measured values. Results from this study provide increased insight into gravity sag behavior in gossamer structures, and demonstrates the potential to analytically predict gravity-induced deformations to within reasonable accuracy.

  15. Aloe vera gel protects liver from oxidative stress-induced damage in experimental rat model.

    PubMed

    Nahar, Taslima; Uddin, Borhan; Hossain, Shahdat; Sikder, Abdul Mannan; Ahmed, Sohel

    2013-01-01

    Aloe vera is a semi-tropical plant of Liliaceae family which has a wide range of applications in traditional medicine. In the present study, we sought to investigate the heptaoprotective potential of Aloe vera gel as a diet supplement. To achieve this goal, we have designed in vitro and in vivo experimental models of chemical-induced liver damage using male Sprague-Dawley rat. In the in vitro model, its effect was evaluated on Fenton's reaction-induced liver lipid peroxidation. Co-incubation with gel significantly reduced the generation of liver lipid peroxide (LPO). Next, to see the similar effect in vivo, gel was orally administered to rats once daily for 21 successive days. Following 1 hour of the last administration of gel, rats were treated with intra-peritoneal injection of CCl4. Dietary gel showed significant hepatoprotection against CCl4-induced damage as evident by restoration of liver LPO, serum transaminases, alkaline phosphatase, and total bilirubin towards near normal. The beneficial effects were pronounced with the doses used (400 and 800 mg/kg body weight). Besides, we did not observe any significant drop in serum albumin, globulin as well as total protein levels of gel-administered rats. Histopathology of the liver tissue further supported the biochemical findings confirming the hepatoprotective potential of dietary gel. PMID:23652643

  16. Effects of Schizolobium parahyba Extract on Experimental Bothrops Venom-Induced Acute Kidney Injury

    PubMed Central

    Martines, Monique Silva; Mendes, Mirian M.; Shimizu, Maria H. M.; Melo Rodrigues, Veridiana; de Castro, Isac; Filho, Sebastião R. Ferreira; Malheiros, Denise M. A. C.; Yu, Luis; Burdmann, Emmanuel A.

    2014-01-01

    Background Venom-induced acute kidney injury (AKI) is a frequent complication of Bothrops snakebite with relevant morbidity and mortality. The aim of this study was to assess the effects of Schizolobium parahyba (SP) extract, a natural medicine with presumed anti-Bothrops venom effects, in an experimental model of Bothrops jararaca venom (BV)-induced AKI. Methodology Groups of 8 to 10 rats received infusions of 0.9% saline (control, C), SP 2 mg/kg, BV 0.25 mg/kg and BV immediately followed by SP (treatment, T) in the doses already described. After the respective infusions, animals were assessed for their glomerular filtration rate (GFR, inulin clearance), renal blood flow (RBF, Doppler), blood pressure (BP, intra-arterial transducer), renal vascular resistance (RVR), urinary osmolality (UO, freezing point), urinary neutrophil gelatinase-associated lipocalin (NGAL, enzyme-linked immunosorbent assay [ELISA]), lactate dehydrogenase (LDH, kinetic method), hematocrit (Hct, microhematocrit), fibrinogen (Fi, Klauss modified) and blinded renal histology (acute tubular necrosis score). Principal Findings BV caused significant decreases in GFR, RBF, UO, HcT and Fi; significant increases in RVR, NGAL and LDH; and acute tubular necrosis. SP did not prevent these changes; instead, it caused a significant decrease in GFR when used alone. Conclusion SP administered simultaneously with BV, in an approximate 10∶1 concentration, did not prevent BV-induced AKI, hemolysis and fibrinogen consumption. SP used alone caused a decrease in GFR. PMID:24551041

  17. Diet shifts and population dynamics of estuarine foraminifera during ecosystem recovery after experimentally induced hypoxia crises

    NASA Astrophysics Data System (ADS)

    Brouwer, G. M.; Duijnstee, I. A. P.; Hazeleger, J. H.; Rossi, F.; Lourens, L. J.; Middelburg, J. J.; Wolthers, M.

    2016-03-01

    This study shows foraminiferal dynamics after experimentally induced hypoxia within the wider context of ecosystem recovery. 13C-labeled bicarbonate and glucose were added to the sediments to examine foraminiferal diet shifts during ecosystem recovery and test-size measurements were used to deduce population dynamics. Hypoxia-treated and undisturbed patches were compared to distinguish natural (seasonal) fluctuations from hypoxia-induced responses. The effect of timing of disturbance and duration of recovery were investigated. The foraminiferal diets and population dynamics showed higher fluctuations in the recovering patches compared to the controls. The foraminiferal diet and population structure of Haynesina germanica and Ammonia beccarii responded differentially and generally inversely to progressive stages of ecosystem recovery. Tracer inferred diet estimates in April and June and the two distinctly visible cohorts in the test-size distribution, discussed to reflect reproduction in June, strongly suggest that the ample availability of diatoms during the first month of ecosystem recovery after the winter hypoxia was likely profitable to A. beccarii. Enhanced reproduction itself was strongly linked to the subsequent dietary shift to bacteria. The distribution of the test dimensions of H. germanica indicated that this species had less fluctuation in population structure during ecosystem recovery but possibly reproduced in response to the induced winter hypoxia. Bacteria seemed to consistently contribute more to the diet of H. germanica than diatoms. For the diet and test-size distribution of both species, the timing of disturbance seemed to have a higher impact than the duration of the subsequent recovery period.

  18. Evaluation of anti-urolithiatic activity of Pashanabhedadi Ghrita against experimentally induced renal calculi in rats.

    PubMed

    Gupta, Sanjay Kumar; Baghel, Madhav Singh; Bhuyan, Chaturbhuja; Ravishankar, B; Ashok, B K; Patil, Panchakshari D

    2012-07-01

    Population in an industrialized world is afflicted by urinary stone disease. Kidney stones are common in all kinds of urolithiasis. One distinguished formulation mentioned by Sushruta for management of Ashmari (urolithiasis) is Pashanabhedadi Ghrita (PBG), which is in clinical practice since centuries. Validation of drug is the requirement of time through the experimental study. In this study, trial of PBG has been made against ammonium oxalate rich diet and gentamicin injection induced renal calculi in albino rats. The calculi were induced by gentamicin injection and ammonium oxalate rich diet. Test drug was administered concomitantly in the dose of 900 mg/kg for 15 consecutive days. Rats were sacrificed on the 16(th) day. Parameters like kidney weight, serum biochemical, kidney tissue and histopathology of kidney were studied. Concomitant treatment of PBG attenuates blood biochemical parameters non-significantly, where as it significantly attenuated lipid peroxidation and enhanced glutathione and glutathione peroxidase activities. It also decreased crystal deposition markedly into the renal tubules in number as well as size and prevented damage to the renal tubules. The findings showed that PBG is having significant anti-urolithiatic activities against ammonium oxalate rich diet plus gentamicine injection induced urolithiasis in rats. PMID:23723654

  19. Acute experimentally induced neck pain does not affect fatigability of the peripheral biceps brachii muscle.

    PubMed

    Hung, Laurie Y; Maracle, Emmalee; Srbely, John Z; Brown, Stephen H M

    2014-10-01

    Evidence has shown that upper limb muscles peripheral to the cervical spine, such as the biceps brachii, can demonstrate functional deficits in the presence of chronic neck pain. However, few studies have examined how neck pain can affect the fatigability of upper limb muscles; therefore we were motivated to investigate the effects of acutely induced neuropathic neck pain on the fatigability of the biceps brachii muscle during isometric contraction to exhaustion. Topical capsaicin was used to induce neck pain in 11 healthy male participants. Surface EMG signals were recorded from the biceps brachii during an isometric elbow flexion fatigue task in which participants held a weight equivalent to 30% of their MVC until exhaustion. Two experimental sessions, one placebo and one capsaicin, were conducted separated by two days. EMG mean power frequency and average normalized activation values were calculated over the course of the fatigue task. In the presence of pain, there was no statistically significant effect on EMG parameters during fatigue of the biceps brachii. These results demonstrate that acutely induced neuropathic neck pain does not affect the fatigability, under the tested conditions, of the biceps brachii. PMID:24718930

  20. Effects of transdermal tulobuterol on dyspnea and respiratory function during exercise in patients with chronic obstructive pulmonary disease

    PubMed Central

    Ichikawa, Masako; Yoshimi, Kaku; Shiota, Satomi; Kotajima, Masaki; Nakajyo, Mami; Seyama, Kuniaki; Fukuchi, Yoshinosuke; Takahashi, Kazuhisa

    2015-01-01

    Background Poor exercise tolerability is a major barrier to improving the quality of life of patients with chronic obstructive pulmonary disease (COPD). Although COPD is often treated with long-acting β2 adrenergic agonists, few studies have examined their effects on exercise tolerability. Methods In this study, Japanese COPD patients were treated with 2 mg transdermal tulobuterol, a long-acting β2 agonist, once daily for 4 weeks. Spirometry and exercise tests were conducted at baseline and at the end of treatment. The patients conducted constant load (30 W for 5 min) and incremental load (starting at 10 W and increasing by 10 W every 1 min for 5 min to a maximum load of 50 W) exercise tests on a cycle ergometer. Results Thirteen patients with stable COPD participated in this study (mean age ± standard deviation (SD), 69.5±9.7 years; smoking history 55.9±27.8 pack-years). Resting spirometric parameters were unchanged at the end of treatment. The maximum Borg scale for dyspnea and the Borg scale slope (BSS) decreased significantly from baseline to the end of treatment. The threshold load of dyspnea (TLD) increased slightly, although not significantly, in the constant load test but not in the incremental load test. There were no changes in respiratory parameters during exercise after treatment. Conclusions In conclusion, we found that treatment with transdermal tulobuterol for 4 weeks improved self-assessed dyspnea in Japanese COPD patients during constant and incremental exercise tests. This improvement in dyspnea may encourage patients to perform daily life activities or regular physical activity. PMID:25973235

  1. Left atrial volume as an independent predictor of exercise capacity in patients with isolated diastolic dysfunction presented with exertional dyspnea

    PubMed Central

    2014-01-01

    Background Left atrial volume (LAV) and exercise capacity are important prognostic determinants of cardiovascular risk. Exercise intolerance and increased LAV are expected in patients with diastolic dysfunction. While dyspnea is the symptom reported by the patient and considered subjective, exercise capacity obtained by exercise testing provides an objective measure of cardiovascular fitness. The objective of this study is to determine the relationship between LAV index and exercise capacity in patients with isolated diastolic dysfunction who presented with exertional dyspnea. Methods We studied consecutive patients with dyspnea who underwent treadmill exercise testing and transthoracic echocardiography on the same day. LAV was assessed using the biplane area-length method. Symptom-limited exercise testing was performed immediately after echocardiography. Patients with coronary artery disease, valvular or congenital heart disease, left ventricular systolic dysfunction, pulmonary hypertension or positive exercise test were excluded. Results The study consisted of 111 patients (58.1 ± 9.2 years of age, 54.1% male, 64% hypertension, 57.7% dyslipidemia and 20.7% diabetes). The exercise duration and capacity were 6.8 ± 2.1 minutes and 7.7 ± 1.9 METs, respectively. Left ventricular ejection fraction and LAV index was 71.0 ± 5.8% and 31.4 ± 10.5 ml/m2, respectively. In multivariate analysis, age [odds ratios (OR) 0.94; 95% confidence interval (CI) 0.89-0.99], body mass index (OR 0.82, 95% CI 0.72-0.93), and LAV index (OR 0.92, 95% CI 0.87-0.97) were associated with good exercise capacity. Conclusion In patients with isolated diastolic dysfunction and exertional dyspnea, an increased LAV index, a marker of chronic diastolic dysfunction, is associated with poor exercise capacity. PMID:24929939

  2. Spectroscopic evaluation of painted layer structural changes induced by gamma radiation in experimental models

    NASA Astrophysics Data System (ADS)

    Manea, Mihaela M.; Moise, Ioan V.; Virgolici, Marian; Negut, Constantin D.; Barbu, Olimpia-Hinamatsuri; Cutrubinis, Mihalis; Fugaru, Viorel; Stanculescu, Ioana R.; Ponta, Corneliu C.

    2012-02-01

    The degradation of cultural heritage objects by insects and microorganisms is an important issue for conservators, art specialists and humankind in general. Gamma irradiation is an efficient method of polychrome wooden artifacts disinfestation. Color changes and other modifications in the physical chemical properties of materials induced by gamma irradiation are feared by cultural heritage responsible committees and they have to be evaluated objectively and precisely. In this paper FTIR and FT-Raman spectroscopy methods were used to investigate the structural changes in some experimental models of tempera paint layers on wood following 11 kGy gamma irradiation at two dose rates. Radiation chemistry depends on the particular pigment, matrix formed by protein, resin (in case of varnished samples) and water presence. For the majority of painted layer in experimental models very small spectral variations were observed. Small changes in the FTIR spectra were observed for the raw sienna experimental model: for the higher dose rate the egg yolk protein oxidation peaks and the CH stretching bands due to lipids degradation products increased.

  3. Radiating plasma species density distribution in EUV-induced plasma in argon: a spatiotemporal experimental study

    NASA Astrophysics Data System (ADS)

    van der Horst, R. M.; Beckers, J.; Osorio, E. A.; van de Ven, T. H. M.; Banine, V. Y.

    2015-12-01

    In this contribution we experimentally study temporally and spatially resolved radiating plasma species density distribution in plasma induced by irradiating a low pressure argon gas with high energy photons with a wavelength of 13.5 nm, i.e. extreme ultraviolet (EUV). This is done by recording the optical emission spatially and temporally resolved by an iCCD camera as a function of the argon gas pressure. Our experimental results show that the emission intensity, i.e. density of radiating plasma species, depends quadratically on the gas pressure. The linear term is due to photoionization and simultaneous excitation by EUV photons, the quadratic term due to electron impact excitation by electrons generated by photoionization. The decay of radiating plasma species can be divided into two phases. At time scales shorter than 10 μs (first phase), the decay is governed by radiative decay of radiating plasma species. At longer time scales (second phase, >10 μs), the decay is dominated by diffusion and subsequent de-excitation at the wall. The experimental decay and expansion during this phase corresponds well with a simplified diffusion model. In order to gain more insight in this exotic type of plasma, we compare the electron density from previous measurements with the results obtained here.

  4. Effects of Experimental Sarcocystis neurona-Induced Infection on Immunity in an Equine Model

    PubMed Central

    Lewis, S. Rochelle; Ellison, Siobhan P.; Dascanio, John J.; Lindsay, David S.; Gogal, Robert M.; Werre, Stephen R.; Surendran, Naveen; Breen, Meghan E.; Heid, Bettina M.; Andrews, Frank M.; Buechner-Maxwell, Virginia A.; Witonsky, Sharon G.

    2014-01-01

    Sarcocystis neurona is the most common cause of Equine Protozoal Myeloencephalitis (EPM), affecting 0.5–1% horses in the United States during their lifetimes. The objective of this study was to evaluate the equine immune responses in an experimentally induced Sarcocystis neurona infection model. Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators. Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression. All experimentally infected horses displayed neurologic signs after infection. Neutrophils, monocytes, and lymphocytes from infected horses displayed significantly delayed apoptosis at some time points. Cell proliferation was significantly increased in S. neurona-infected horses when stimulated nonspecifically with PMA/I but significantly decreased when stimulated with S. neurona compared to controls. Collectively, our results suggest that horses experimentally infected with S. neurona manifest impaired antigen specific response to S. neurona, which could be a function of altered antigen presentation, lack of antigen recognition, or both. PMID:26464923

  5. Effects of Experimental Sarcocystis neurona-Induced Infection on Immunity in an Equine Model.

    PubMed

    Lewis, S Rochelle; Ellison, Siobhan P; Dascanio, John J; Lindsay, David S; Gogal, Robert M; Werre, Stephen R; Surendran, Naveen; Breen, Meghan E; Heid, Bettina M; Andrews, Frank M; Buechner-Maxwell, Virginia A; Witonsky, Sharon G

    2014-01-01

    Sarcocystis neurona is the most common cause of Equine Protozoal Myeloencephalitis (EPM), affecting 0.5-1% horses in the United States during their lifetimes. The objective of this study was to evaluate the equine immune responses in an experimentally induced Sarcocystis neurona infection model. Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators. Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression. All experimentally infected horses displayed neurologic signs after infection. Neutrophils, monocytes, and lymphocytes from infected horses displayed significantly delayed apoptosis at some time points. Cell proliferation was significantly increased in S. neurona-infected horses when stimulated nonspecifically with PMA/I but significantly decreased when stimulated with S. neurona compared to controls. Collectively, our results suggest that horses experimentally infected with S. neurona manifest impaired antigen specific response to S. neurona, which could be a function of altered antigen presentation, lack of antigen recognition, or both. PMID:26464923

  6. Numerical and experimental studies of coupling-induced phase shift in resonator and interferometric integrated optics devices.

    PubMed

    Tobing, L Y M; Tjahjana, L; Darmawan, S; Zhang, D H

    2012-02-27

    Coupling induced effects are higher order effects inherent in waveguide evanescent coupling that are known to spectrally distort optical performances of integrated optics devices formed by coupled resonators. We present both numerical and experimental studies of coupling-induced phase shift in various basic integrated optics devices. Rigorous finite difference time domain simulations and systematic experimental characterizations of different basic structures were conducted for more accurate parameter extraction, where it can be observed that coupling induced wave vector may change sign at the increasing gap separation. The devices characterized in this work were fabricated by CMOS-process 193 nm Deep UV (DUV) lithography in silicon-on-insulator (SOI) technology. PMID:22418385

  7. Dyspnea on exertion in patients of heart failure as a consequence of obesity: An observational study.

    PubMed

    Baikampady, Savitri Vasudev

    2013-04-01

    Heart failure (HF) is the inability of the heart to fill with or pump out enough blood to meet the body's needs. It is not one single disease, but rather a group of signs and symptoms caused by many different disease processes that have weakened the heart over time and left it unable to pump blood efficiently. Hypertension, diabetes mellitus, cardiovascular disorders are few of such disease processes responsible for conditions in HF. Even though, the co-morbidities mentioned above are well-established in the present system of medicine, its association with respiratory risk on obese patients especially in HF, still needs to be explored. The aim of this study is to determine the presence of dyspnea on exertion (DOE) in patients of HF as a consequence of obesity. Strategies to prevent the risk of HF, which would complement the current approaches aimed at Ayurvedic perspective especially, the obesity, its related comorbidities and contributors in the form of information on life-style leading to obesity needs to be focused. An ethical clearance for the project from the same institute was obtained on 101 patients of HF. All patients with ejection fraction <50% having DOE, New York Heart Association category were selected. Those with restrictive cardiomyopathy valvular abnormalities and under psychiatry treatment were excluded. Patients were informed about the project and their written consent was obtained followed by filling the Case Report Form (CRF). Their recent reports of left ventricular ejection fraction were attached along with details of 6 min hall walk test. Analysis was performed using the Statistical Package for the Social Sciences software, IBM version-17.0. The significant outcomes on lifestyles of HF related to co-morbidities were found. PMID:24250124

  8. Dyspnea on exertion in patients of heart failure as a consequence of obesity: An observational study

    PubMed Central

    Baikampady, Savitri Vasudev

    2013-01-01

    Heart failure (HF) is the inability of the heart to fill with or pump out enough blood to meet the body's needs. It is not one single disease, but rather a group of signs and symptoms caused by many different disease processes that have weakened the heart over time and left it unable to pump blood efficiently. Hypertension, diabetes mellitus, cardiovascular disorders are few of such disease processes responsible for conditions in HF. Even though, the co-morbidities mentioned above are well-established in the present system of medicine, its association with respiratory risk on obese patients especially in HF, still needs to be explored. The aim of this study is to determine the presence of dyspnea on exertion (DOE) in patients of HF as a consequence of obesity. Strategies to prevent the risk of HF, which would complement the current approaches aimed at Ayurvedic perspective especially, the obesity, its related comorbidities and contributors in the form of information on life-style leading to obesity needs to be focused. An ethical clearance for the project from the same institute was obtained on 101 patients of HF. All patients with ejection fraction <50% having DOE, New York Heart Association category were selected. Those with restrictive cardiomyopathy valvular abnormalities and under psychiatry treatment were excluded. Patients were informed about the project and their written consent was obtained followed by filling the Case Report Form (CRF). Their recent reports of left ventricular ejection fraction were attached along with details of 6 min hall walk test. Analysis was performed using the Statistical Package for the Social Sciences software, IBM version-17.0. The significant outcomes on lifestyles of HF related to co-morbidities were found. PMID:24250124

  9. Unexplained exertional dyspnea caused by low ventricular filling pressures: results from clinical invasive cardiopulmonary exercise testing

    PubMed Central

    Lewis, Gregory D.; Opotowsky, Alexander R.; Waxman, Aaron B.; Systrom, David M.

    2016-01-01

    Abstract To determine whether low ventricular filling pressures are a clinically relevant etiology of unexplained dyspnea on exertion, a database of 619 consecutive, clinically indicated invasive cardiopulmonary exercise tests (iCPETs) was reviewed to identify patients with low maximum aerobic capacity (V̇o2max) due to inadequate peak cardiac output (Qtmax) with normal biventricular ejection fractions and without pulmonary hypertension (impaired: n = 49, V̇o2max = 53% predicted [interquartile range (IQR): 47%–64%], Qtmax = 72% predicted [62%–76%]). These were compared to patients with a normal exercise response (normal: n = 28, V̇o2max = 86% predicted [84%–97%], Qtmax = 108% predicted [97%–115%]). Before exercise, all patients received up to 2 L of intravenous normal saline to target an upright pulmonary capillary wedge pressure (PCWP) of ≥5 mmHg. Despite this treatment, biventricular filling pressures at peak exercise were lower in the impaired group than in the normal group (right atrial pressure [RAP]: 6 [IQR: 5–8] vs. 9 [7–10] mmHg, P = 0.004; PCWP: 12 [10–16] vs. 17 [14–19] mmHg, P < 0.001), associated with decreased stroke volume (SV) augmentation with exercise (+13 ± 10 [standard deviation (SD)] vs. +18 ± 10 mL/m2, P = 0.014). A review of hemodynamic data from 23 patients with low RAP on an initial iCPET who underwent a second iCPET after saline infusion (2.0 ± 0.5 L) demonstrated that 16 of 23 patients responded with increases in Qtmax ([+24% predicted [IQR: 14%–34%]), V̇o2max (+10% predicted [7%–12%]), and maximum SV (+26% ± 17% [SD]). These data suggest that inadequate ventricular filling related to low venous pressure is a clinically relevant cause of exercise intolerance. PMID:27162614

  10. Unexplained exertional dyspnea caused by low ventricular filling pressures: results from clinical invasive cardiopulmonary exercise testing.

    PubMed

    Oldham, William M; Lewis, Gregory D; Opotowsky, Alexander R; Waxman, Aaron B; Systrom, David M

    2016-03-01

    To determine whether low ventricular filling pressures are a clinically relevant etiology of unexplained dyspnea on exertion, a database of 619 consecutive, clinically indicated invasive cardiopulmonary exercise tests (iCPETs) was reviewed to identify patients with low maximum aerobic capacity (V̇o2max) due to inadequate peak cardiac output (Qtmax) with normal biventricular ejection fractions and without pulmonary hypertension (impaired: n = 49, V̇o2max = 53% predicted [interquartile range (IQR): 47%-64%], Qtmax = 72% predicted [62%-76%]). These were compared to patients with a normal exercise response (normal: n = 28, V̇o2max = 86% predicted [84%-97%], Qtmax = 108% predicted [97%-115%]). Before exercise, all patients received up to 2 L of intravenous normal saline to target an upright pulmonary capillary wedge pressure (PCWP) of ≥5 mmHg. Despite this treatment, biventricular filling pressures at peak exercise were lower in the impaired group than in the normal group (right atrial pressure [RAP]: 6 [IQR: 5-8] vs. 9 [7-10] mmHg, P = 0.004; PCWP: 12 [10-16] vs. 17 [14-19] mmHg, P < 0.001), associated with decreased stroke volume (SV) augmentation with exercise (+13 ± 10 [standard deviation (SD)] vs. +18 ± 10 mL/m(2), P = 0.014). A review of hemodynamic data from 23 patients with low RAP on an initial iCPET who underwent a second iCPET after saline infusion (2.0 ± 0.5 L) demonstrated that 16 of 23 patients responded with increases in Qtmax ([+24% predicted [IQR: 14%-34%]), V̇o2max (+10% predicted [7%-12%]), and maximum SV (+26% ± 17% [SD]). These data suggest that inadequate ventricular filling related to low venous pressure is a clinically relevant cause of exercise intolerance. PMID:27162614

  11. Neutrophil Extracellular Traps Induce Organ Damage during Experimental and Clinical Sepsis

    PubMed Central

    Nascimento, Daniele Carvalho; Sônego, Fabiane; Castanheira, Fernanda Vargas e Silva; Melo, Paulo Henrique; Scortegagna, Gabriela Trentin; Silva, Rangel Leal; Barroso-Sousa, Romualdo; Souto, Fabrício Oliveira; Pazin-Filho, Antonio; Figueiredo, Florencio; Alves-Filho, José Carlos; Cunha, Fernando Queiróz

    2016-01-01

    Organ dysfunction is a major concern in sepsis pathophysiology and contributes to its high mortality rate. Neutrophil extracellular traps (NETs) have been implicated in endothelial damage and take part in the pathogenesis of organ dysfunction in several conditions. NETs also have an important role in counteracting invading microorganisms during infection. The aim of this study was to evaluate systemic NETs formation, their participation in host bacterial clearance and their contribution to organ dysfunction in sepsis. C57Bl/6 mice were subjected to endotoxic shock or a polymicrobial sepsis model induced by cecal ligation and puncture (CLP). The involvement of cf-DNA/NETs in the physiopathology of sepsis was evaluated through NETs degradation by rhDNase. This treatment was also associated with a broad-spectrum antibiotic treatment (ertapenem) in mice after CLP. CLP or endotoxin administration induced a significant increase in the serum concentrations of NETs. The increase in CLP-induced NETs was sustained over a period of 3 to 24 h after surgery in mice and was not inhibited by the antibiotic treatment. Systemic rhDNase treatment reduced serum NETs and increased the bacterial load in non-antibiotic-treated septic mice. rhDNase plus antibiotics attenuated sepsis-induced organ damage and improved the survival rate. The correlation between the presence of NETs in peripheral blood and organ dysfunction was evaluated in 31 septic patients. Higher cf-DNA concentrations were detected in septic patients in comparison with healthy controls, and levels were correlated with sepsis severity and organ dysfunction. In conclusion, cf-DNA/NETs are formed during sepsis and are associated with sepsis severity. In the experimental setting, the degradation of NETs by rhDNase attenuates organ damage only when combined with antibiotics, confirming that NETs take part in sepsis pathogenesis. Altogether, our results suggest that NETs are important for host bacterial control and are

  12. Correlation Between Stereoacuity and Experimentally Induced Graded Monocular and Binocular Astigmatism

    PubMed Central

    Puthran, Neelam; Gagal, Bhavna

    2016-01-01

    Introduction Stereopsis, the highest grade of binocular single vision, is affected by various factors, such as mis-alignment of visual axes, refractive errors especially anisometropia and astigmatism, both of which may result in amblyopia. There are very few studies in literature regarding the relationship between stereoacuity and refractive errors, especially astigmatism. Aim The present study was conducted to determine the correlation between stereoacuity and experimentally induced graded astigmatism in emmetropes. Materials and Methods A randomized study was conducted on 2000 individuals of either gender, between the ages of 8-35 years, at tertiary care centre attached to a medical college during the period of August 2012 to August 2014, All subjects were emmetropic with normal binocular single vision. Participants were randomly divided into four groups of 500 individuals each. Two groups were subjected to induced myopic astigmatism, either uni-ocularly or binocularly, using + 1.0 D and + 2.0 D cylinders at varying axes i.e., 450, 900 and 1800. Similarily, the remaining two groups were subjected to induced hypermetropic astigmatism, using - 1.0 D and - 2.0D cylinders at varying axes i.e. 450, 900 and 1800. Near stereoacuity was determined by the Titmus Fly Stereo Test, both before and after induction of astigmatism. Statistical analysis was done using paired t-test and ANOVA. Results The mean stereoacuity in emmetropes was 28.81±4.97 seconds of arc. There was a decrease in stereoacuity with increase in dioptric power of astigmatism (p<0.001). Oblique astigmatism reduced the stereoacuity maximally, while stereoacuity was least affected at 180o axis. Hypermetropic astigmatism caused more deterioration in stereoacuity than myopic astigmatism. A gross reduction in stereoacuity was noted in induced monocular astigmatism as against binocular astigmatism. Conclusion This study suggests that stereoacuity is significantly affected by even minor degrees of monocular or

  13. Spontaneous and experimental glycoprotein storage disease of goats induced by Ipomoea carnea subsp fistulosa (Convolvulaceae).

    PubMed

    Armién, A G; Tokarnia, C H; Peixoto, P Vargas; Frese, K

    2007-03-01

    Spontaneous and experimental poisoning with the swainsonine-containing and calystegine-containing plant Ipomoea carnea subsp fistulosa is described. Three of 8 goats presenting with emaciation, weakness, symmetrical ataxia, posterior paresis, proprioceptive deficits, abnormal posture, abnormal postural reaction, and muscle hypertonia were necropsied. I fistulosa was suspected to be the cause of the neurologic disease in all cases. An experiment was conducted to confirm the diagnosis using 12 goats and diets containing 3 different concentrations of the plant. All goats fed I fistulosa developed neurological signs that were similar to those observed in the spontaneous intoxication. Muscle atrophy and pallor were the only macroscopic changes observed in spontaneous and in experimental intoxication. Histological lesions of spontaneous and experimental animals were similar. The most prominent lesion was cytoplasmic vacuolation in neurons of the central and the autonomous nervous system, pancreatic acinar cells, hepatocytes, Kupffer cells, follicular epithelial cells of the thyroid gland, and macrophages of the lymphatic tissues. Neuronal necrosis, axonal spheroids formation, and astrogliosis were additionally observed in the brain. Ultrastructurally, the cytoplasmic vacuoles consisted of distended lysosomes surrounded by a single-layered membrane. Nonreduced end-rests or sequence of alpha-Man, alpha-Glc, beta(1-4)-GlcNAc, and NeuNAc on lysosomal membrane were revealed by lectin histochemistry. Samples of plants used in the experimental trial contained swainsonine and calystegine and their intermediary derivate. We conclude that I fistulosa induces a glycoprotein storage disease primarily based on the inhibition of the lysosomal alpha-mannosidase by the alkaloid swainsonine. PMID:17317794

  14. Protein and microRNA biomarkers from lavage, urine, and serum in military personnel evaluated for dyspnea

    DOE PAGESBeta

    Brown, Joseph N.; Brewer, Heather M.; Nicora, Carrie D.; Weitz, Karl K.; Morris, Michael J.; Skabelund, Andrew J.; Adkins, Joshua N.; Smith, Richard D.; Cho, Ji -Hoon; Gelinas, Richard

    2014-10-05

    Background: We have identified candidate protein and microRNA (miRNA) biomarkers for dyspnea by studying serum, lavage fluid, and urine from military personnel who reported serious respiratory symptoms after they were deployed to Iraq or Afghanistan. Methods: Forty-seven soldiers with the complaint of dyspnea who enrolled in the STudy of Active Duty Military Personnel for Environmental Dust Exposure (STAMPEDE) underwent comprehensive pulmonary evaluations at the San Antonio Military Medical Center. The evaluation included fiber-optic bronchoscopy with bronchoalveolar lavage. The clinical findings from the STAMPEDE subjects pointed to seven general underlying diagnoses or findings including airway hyperreactivity, asthma, low diffusivity of carbonmore » monoxide, and abnormal cell counts. The largest category was undiagnosed. As an exploratory study, not a classification study, we profiled proteins or miRNAs in lavage fluid, serum, or urine in this group to look for any underlying molecular patterns that might lead to biomarkers. Proteins in lavage fluid and urine were identified by accurate mass tag (database-driven) proteomics methods while miRNAs were profiled by a hybridization assay applied to serum, urine, and lavage fluid. Results: Over seventy differentially expressed proteins were reliably identified both from lavage and from urine in forty-eight dyspnea subjects compared to fifteen controls with no known lung disorder. Six of these proteins were detected both in urine and lavage. One group of subjects was distinguished from controls by expressing a characteristic group of proteins. A related group of dyspnea subjects expressed a unique group of miRNAs that included one miRNA that was differentially overexpressed in all three fluids studied. The levels of several miRNAs also showed modest but direct associations with several standard clinical measures of lung health such as forced vital capacity or gas exchange efficiency. Conclusions: Candidate proteins

  15. Protein and microRNA biomarkers from lavage, urine, and serum in military personnel evaluated for dyspnea

    SciTech Connect

    Brown, Joseph N.; Brewer, Heather M.; Nicora, Carrie D.; Weitz, Karl K.; Morris, Michael J.; Skabelund, Andrew J.; Adkins, Joshua N.; Smith, Richard D.; Cho, Ji -Hoon; Gelinas, Richard

    2014-10-05

    Background: We have identified candidate protein and microRNA (miRNA) biomarkers for dyspnea by studying serum, lavage fluid, and urine from military personnel who reported serious respiratory symptoms after they were deployed to Iraq or Afghanistan. Methods: Forty-seven soldiers with the complaint of dyspnea who enrolled in the STudy of Active Duty Military Personnel for Environmental Dust Exposure (STAMPEDE) underwent comprehensive pulmonary evaluations at the San Antonio Military Medical Center. The evaluation included fiber-optic bronchoscopy with bronchoalveolar lavage. The clinical findings from the STAMPEDE subjects pointed to seven general underlying diagnoses or findings including airway hyperreactivity, asthma, low diffusivity of carbon monoxide, and abnormal cell counts. The largest category was undiagnosed. As an exploratory study, not a classification study, we profiled proteins or miRNAs in lavage fluid, serum, or urine in this group to look for any underlying molecular patterns that might lead to biomarkers. Proteins in lavage fluid and urine were identified by accurate mass tag (database-driven) proteomics methods while miRNAs were profiled by a hybridization assay applied to serum, urine, and lavage fluid. Results: Over seventy differentially expressed proteins were reliably identified both from lavage and from urine in forty-eight dyspnea subjects compared to fifteen controls with no known lung disorder. Six of these proteins were detected both in urine and lavage. One group of subjects was distinguished from controls by expressing a characteristic group of proteins. A related group of dyspnea subjects expressed a unique group of miRNAs that included one miRNA that was differentially overexpressed in all three fluids studied. The levels of several miRNAs also showed modest but direct associations with several standard clinical measures of lung health such as forced vital capacity or gas exchange efficiency. Conclusions: Candidate proteins and mi

  16. Protein and microRNA biomarkers from lavage, urine, and serum in military personnel evaluated for dyspnea

    PubMed Central

    2014-01-01

    Background We have identified candidate protein and microRNA (miRNA) biomarkers for dyspnea by studying serum, lavage fluid, and urine from military personnel who reported serious respiratory symptoms after they were deployed to Iraq or Afghanistan. Methods Forty-seven soldiers with the complaint of dyspnea who enrolled in the STudy of Active Duty Military Personnel for Environmental Dust Exposure (STAMPEDE) underwent comprehensive pulmonary evaluations at the San Antonio Military Medical Center. The evaluation included fiber-optic bronchoscopy with bronchoalveolar lavage. The clinical findings from the STAMPEDE subjects pointed to seven general underlying diagnoses or findings including airway hyperreactivity, asthma, low diffusivity of carbon monoxide, and abnormal cell counts. The largest category was undiagnosed. As an exploratory study, not a classification study, we profiled proteins or miRNAs in lavage fluid, serum, or urine in this group to look for any underlying molecular patterns that might lead to biomarkers. Proteins in lavage fluid and urine were identified by accurate mass tag (database-driven) proteomics methods while miRNAs were profiled by a hybridization assay applied to serum, urine, and lavage fluid. Results Over seventy differentially expressed proteins were reliably identified both from lavage and from urine in forty-eight dyspnea subjects compared to fifteen controls with no known lung disorder. Six of these proteins were detected both in urine and lavage. One group of subjects was distinguished from controls by expressing a characteristic group of proteins. A related group of dyspnea subjects expressed a unique group of miRNAs that included one miRNA that was differentially overexpressed in all three fluids studied. The levels of several miRNAs also showed modest but direct associations with several standard clinical measures of lung health such as forced vital capacity or gas exchange efficiency. Conclusions Candidate proteins and mi

  17. Experimental study of the water jet induced by underwater electrical discharge in a narrow rectangular tube

    NASA Astrophysics Data System (ADS)

    Koita, T.; Zhu, Y.; Sun, M.

    2016-05-01

    This paper reports an experimental investigation on the effects of explosion depth and tube width on the water jet induced by an underwater electrical discharge in a narrow rectangular tube. The water jet formation and bubble structure were evaluated from the images recorded by a high-speed video camera. Two typical patterns of jet formation and four general patterns of bubble implosion were observed, depending on the explosion depth and tube width. The velocity of the water jet was calculated from the recorded images. The jet velocity was observed to depend on not only the explosion depth and energy, but also on the tube width. We proposed an empirical formula defining the water jet velocity in the tube as a function of the tube width and explosion depth and energy.

  18. Evaluation of some coagulation parameters in hepatic coccidiosis experimentally induced with Eimeria stiedai in rabbits.

    PubMed

    Cam, Y; Cetin, E; Iça, A; Atalay, O; Cetin, N

    2006-05-01

    The objective of this study was to evaluate some coagulation parameters in hepatic coccidiosis experimentally induced with Eimeria stiedai in rabbits. Fourteen healthy New Zealand rabbits were equally divided into two groups. One group received no treatment, the other group was orally inoculated with 40 000 sporulated oocysts of E. stiedai in a 1 ml inoculum using a catheter. At day 24 after inoculation, blood samples were collected into sodium citrate-containing tubes to evaluate some coagulation parameters. Although statistically not significant, infected rabbits had prolonged prothrombin time and activated partial thromboplastin time compared with rabbits in the control group. A significant reduction (P < 0.05) was observed in the level of fibrinogen of infected rabbits compared with that of the controls. A slight decrease in thrombocyte counts of infected rabbits was not statistically significant. PMID:16629990

  19. Effect of insulin-induced hypoglycaemia on the central nervous system: evidence from experimental studies.

    PubMed

    Jensen, V F H; Bøgh, I B; Lykkesfeldt, J

    2014-03-01

    Insulin-induced hypoglycaemia (IIH) is a major acute complication in type 1 as well as in type 2 diabetes, particularly during intensive insulin therapy. The brain plays a central role in the counter-regulatory response by eliciting parasympathetic and sympathetic hormone responses to restore normoglycaemia. Brain glucose concentrations, being approximately 15-20% of the blood glucose concentration in humans, are rigorously maintained during hypoglycaemia through adaptions such as increased cerebral glucose transport, decreased cerebral glucose utilisation and, possibly, by using central nervous system glycogen as a glucose reserve. However, during sustained hypoglycaemia, the brain cannot maintain a sufficient glucose influx and, as the cerebral hypoglycaemia becomes severe, electroencephalogram changes, oxidative stress and regional neuronal death ensues. With particular focus on evidence from experimental studies on nondiabetic IIH, this review outlines the central mechanisms behind the counter-regulatory response to IIH, as well as cerebral adaption to avoid sequelae of cerebral neuroglycopaenia, including seizures and coma. PMID:24428753

  20. High-intensity laser therapy during chronic degenerative tenosynovitis experimentally induced in broiler chickens

    NASA Astrophysics Data System (ADS)

    Fortuna, Damiano; Rossi, Giacomo; Bilotta, Teresa W.; Zati, Allesandro; Gazzotti, Valeria; Venturini, Antonio; Pinna, Stefania; Serra, Christian; Masotti, Leonardo

    2002-10-01

    The aims of this study was the safety and the efficacy of High Intensity Laser Therapy (HILT) on chronic degenerative tenosynovitis. We have effectuated the histological evaluation and seroassay (C reactive protein) on 18 chickens affect by chronic degenerative tenosynovitis experimentally induced. We have been employed a Nd:YAG laser pulsed wave; all irradiated subjects received the same total energy (270 Joule) with a fluence of 7,7 J/cm2 and intensity of 10,7 W/cm2. The histological findings revealed a distinct reduction of the mineralization of the choral matrix, the anti-inflammatory effect of the laser, the hyperplasia of the synoviocytes and ectasia of the lymphatic vessels.

  1. The use of airborne imaging spectrometer data to determine experimentally induced variation in coniferous canopy chemistry

    NASA Technical Reports Server (NTRS)

    Swanberg, Nancy A.; Matson, Pamela A.

    1987-01-01

    It was experimentally determined whether induced differences in forest canopy chemical composition can be detected using data from the Airborne Imaging Spectrometer (AIS). Treatments were applied to an even-aged forest of Douglas fir trees. Work to date has stressed wet chemical analysis of foilage samples and correction of AIS data. Plot treatments were successful in providing a range of foliar N2 concentrations. Much time was spent investigating and correcting problems with the raw AIS data. Initial problems with groups of drop out lines in the AIS data were traced to the tape recorder and the tape drive. Custom adjustment of the tape drive led to recovery of most missing lines. Remaining individual drop out lines were replaced using average of adjacent lines. Application of a notch filter to the Fourier transform of the image in each band satisfactorily removed vertical striping. The aspect ratio was corrected by resampling the image in the line direction using nearest neighbor interpolation.

  2. An explanation for experimental observations of harmonic cyclotron emission induced by fast ions

    SciTech Connect

    Chen, K.R.; Horton, W.; Van Dam, J.W.

    1993-09-01

    An explanation, supported by numerical simulations and analytical theory, is given for the harmonic cyclotron emission induced by fast ions in tokamak plasmas - particular, for the emission observed at low harmonics in deuterium-deuterium md deuterium-tritium experiments in the Joint European Tokamak. We show that the first proton harmonic is one of the highest spectral peaks whereas the first alpha is weak. We also compare the relative spectral amplitudes of different harmonics. Our results axe consistent with the experimental observations. The simulations verify that the instabilities are caused by a weak relativistic mass effect. Simulation that a nonuniform magnetic field leads to no appreciable change in the growth and saturation amplitude of the waves.

  3. An experimental investigation of vortex-induced vibration with nonlinear restoring forces

    NASA Astrophysics Data System (ADS)

    Mackowski, A. W.; Williamson, C. H. K.

    2013-08-01

    We experimentally examine the amplitude of a bluff body undergoing vortex-induced vibration (VIV) supported by linear and various nonlinear structural forces. This investigation is made possible by our Cyber-Physical Fluid Dynamics force-feedback technique; using it, we can impose arbitrary nonlinear restoring forces on a circular cylinder in our water channel. For the range of nonlinearities examined, detailed analysis allows one to understand and predict the response of the nonlinear structural system using knowledge of a standard, linear VIV system. We also present a case study examining the potential of nonlinear springs to aid in a VIV-based energy harvesting device. Appropriate choices of the spring's nonlinearity allow the hypothetical energy harvester to operate at high performance over a much larger range of Reynolds number than a standard system.

  4. Anti-arthritic effect of eugenol on collagen-induced arthritis experimental model.

    PubMed

    Grespan, Renata; Paludo, Marcia; Lemos, Henrique de Paula; Barbosa, Carmem Patrícia; Bersani-Amado, Ciomar Aparecida; Dalalio, Marcia Machado de Oliveira; Cuman, Roberto Kenji Nakamura

    2012-01-01

    This study was designed to test the efficacy of eugenol, a compound obtained from the essential oil of cloves (Syzygium aromaticum) in collagen-induced arthritis (CIA), a well characterized murine model of rheumatoid arthritis. Macroscopic clinical evidence of CIA manifests first as periarticular erythema and edema in the hind paws. Treatment with eugenol starting at the onset of arthritis (day 25) ameliorated these clinical signs of CIA. Furthermore, eugenol inhibited mononuclear cell infiltration into the knee joints of arthritic mice and also lowered the levels of cytokines (tumor necrosis factor (TNF)-α, interferon (IFN)-γ and tumor growth factor (TGF)-β) within the ankle joints. Eugenol treatment did not affect the in vitro cell viability as assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Therefore, eugenol ameliorates experimental arthritis and could be useful as a beneficial supplement in treating human arthritis. PMID:23037170

  5. Experimental investigation of a supersonic swept ramp injector using laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Hartfield, Roy J.; Hollo, Steven D.; Mcdaniel, James C.

    1990-01-01

    Planar measurements of injectant mole fraction and temperature have been conducted in a nonreacting supersonic combustor configured with underexpanded injection in the base of a swept ramp. The temperature measurements were conducted with a Mach 2 test section inlet in streamwise planes perpendicular to the test section wall on which the ramp was mounted. Injection concentration measurements, conducted in cross flow planes with both Mach 2 and Mach 2.9 free stream conditions, dramatically illustrate the domination of the mixing process by streamwise vorticity generated by the ramp. These measurements, conducted using a nonintrusive optical technique (laser-induced iodine fluorescence), provide an accurate and extensive experimental data base for the validation of computation fluid dynamic codes for the calculation of highly three-dimensional supersonic combustor flow fields.

  6. Nanolesions induced by heavy ions in human tissues: Experimental and theoretical studies

    PubMed Central

    Bleicher, Marcus; Burigo, Lucas; Herrlitz, Maren; Krämer, Michael; Mishustin, Igor; Müller, Iris; Natale, Francesco; Pshenichnov, Igor; Schramm, Stefan; Taucher-Scholz, Gisela; Wälzlein, Cathrin

    2012-01-01

    Summary The biological effects of energetic heavy ions are attracting increasing interest for their applications in cancer therapy and protection against space radiation. The cascade of events leading to cell death or late effects starts from stochastic energy deposition on the nanometer scale and the corresponding lesions in biological molecules, primarily DNA. We have developed experimental techniques to visualize DNA nanolesions induced by heavy ions. Nanolesions appear in cells as “streaks” which can be visualized by using different DNA repair markers. We have studied the kinetics of repair of these “streaks” also with respect to the chromatin conformation. Initial steps in the modeling of the energy deposition patterns at the micrometer and nanometer scale were made with MCHIT and TRAX models, respectively. PMID:23019551

  7. Modulation of diabetes-mellitus-induced male reproductive dysfunctions in experimental animal models with medicinal plants

    PubMed Central

    Jain, Gyan Chand; Jangir, Ram Niwas

    2014-01-01

    Today diabetes mellitus has emerged as a major healthcare problem throughout the world. It has recently broken the age barrier and has been diagnosed in younger people also. Sustained hyperglycemia is associated with many complications including male reproductive dysfunctions and infertility. Numerous medicinal plants have been used for the management of the diabetes mellitus in various traditional system of medicine and in folklore worldwide as they are a rich source of bioactive phytoconstituents, which lower blood glucose level and/or also act as antioxidants resulting in the amelioration of oxidative-stress-induced diabetic complications. The present review describes the ameliorative effects of medicinal plants or their products, especially on male reproductive dysfunctions, in experimental diabetic animal models. PMID:25125884

  8. Scoliosis in rats with experimentally-induced hemiparkinsonism: dependence upon striatal dopamine denervation.

    PubMed Central

    Herrera-Marschitz, M; Utsumi, H; Ungerstedt, U

    1990-01-01

    Rats suffering from experimental hemiparkinsonism induced by a unilateral injection of 6-hydroxydopamine into the left area ventralis tegmenti showed a strong ipsilateral deviation and scoliosis-like skeletal deformity. The rats often showed single rotatory curves affecting the thoracic and lumbar regions, although cases with multiple curves were also found. The severity of the scoliosis was closely related to a decrease in extracellular striatal dopamine measured with microdialysis and to the development of postsynaptic dopamine receptor supersensitivity, functionally evaluated with rotational behaviour elicited with apomorphine. Indeed, rats with the strongest dopamine depletion (greater than 95%) and the strongest rotational responses showed the sharpest spinal deviation and skeletal deformity. These findings agree with the clinical observations that scoliosis occurs in patients with Parkinson's disease and its direction is correlated with the side of the major signs and symptoms of parkinsonism. Images PMID:2303830

  9. Experimental studies of collective excitations of a BEC in light-induced gauge fields

    NASA Astrophysics Data System (ADS)

    Li, Chuan-Hsun; Niffenegger, Robert; Blasing, David; Olson, Abraham; Chen, Yong P.

    2015-05-01

    We present our experimental studies of collective modes including spin dipole mode and scissors mode of a 87Rb Bose-Einstein condensate (BEC) in the presence of Raman light-induced gauge fields and synthetic spin-orbit coupling (SOC). By Raman dressing the mf spin states within the F =1 manifold, we engineer atoms' energy-momentum dispersion to create synthetic SOC, and spin dependent synthetic electric and magnetic fields. We have used spin dependent synthetic electric fields to make two BECs with different spins oscillate and collide in the optical trap. We have studied the effects of SOC on both the momentum damping and thermalization behaviors of the BECs when undergoing such spin dipole oscillations. We have also used spatially dependent synthetic electric fields to excite the scissors mode, which has been used as a probe for superfluidity. We have investigated the effects of the synthetic gauge fields and SOC on the measured scissors mode.

  10. Efficacy and safety of albendazole against experimentally induced Fasciola hepatica infections in goats.

    PubMed

    Foreyt, W J

    1988-01-01

    Forty 8-week-old goats were allocated to five groups of equal size to determine the optimal dosage of albendazole against experimentally induced 14-week-old Fasciola hepatica infections. Albendazole suspension given orally at 5.0, 7.5, 10.0 and 15 mg kg-1 of body weight was 73.3, 88.2, 88.3 and 95.9% effective, respectively, when compared to untreated controls. Mean number of F. hepatica in the untreated control goats was 75.4. No signs of toxicity were observed. When albendazole was given to eight, 8-week-old goats orally at 75 mg kg-1 (five times the optimal dosage), no signs of toxicity were observed. PMID:3347986

  11. Autoantibody profile in the experimental model of scleroderma induced by type V human collagen

    PubMed Central

    Callado, Maria R M; Viana, Vilma S T; Vendramini, Margarete B G; Leon, Elaine P; Bueno, Cleonice; Velosa, Ana P P; Teodoro, Walcy R; Yoshinari, Natalino H

    2007-01-01

    The aim of this study is to evaluate the humoral autoimmune response in the experimental model of systemic sclerosis (SSc) induced by human type V collagen (huCol V). New Zealand rabbits were immunized with huCol V in Freund's complete adjuvant (FCA) and boosted twice with 15 days intervals with huCol V in Freund's incomplete adjuvant. Control groups included animals injected only with FCA or bovine serum albumin. Bleeding was done at days 0, 30, 75 and 120. Tissue specimens were obtained for histopathological investigation. Serological analysis included detection of antibodies against huCol V and anti-topoisomerase I (Anti-Scl70) by enzyme-linked immunosorbent assay, antinuclear antibodies (ANA) by indirect immunofluorescence, and rheumatoid factor (RF) by a latex agglutination test. Target antigens were characterized by immunoblot. Histological analysis revealed extracellular matrix remodeling with fibrosis and vasculitis. Anti-Scl70 and ANA were detected as early as 30 days in all huCol V animals. The universal ANA staining pattern was Golgi-like. This serum reactivity was not abolished by previous absorption with huCol V. Characterization of the target antigen by immunoblot revealed two major protein fractions of 175 000 and 220 000 MW. Similarly to ANA, there was a gradual increase of reactivity throughout the immunization and also it was not abolished by preincubation of serum samples with huCol V. RF testing was negative in hyperimmune sera. Conclusion: The production of autoantibodies, including anti-Scl70, a serological marker for SSc associated with histopathological alterations, validates huCol V induced-experimental model and brings out its potential for understanding the pathophysiology of SSc. PMID:17442023

  12. Angiopoietin-2 enhances survival in experimental sepsis induced by multidrug-resistant Pseudomonas aeruginosa.

    PubMed

    Tzepi, Ira-Maria; Giamarellos-Bourboulis, Evangelos J; Carrer, Dionyssia-Pinelopi; Tsaganos, Thomas; Claus, Ralf A; Vaki, Ilia; Pelekanou, Aimilia; Kotsaki, Antigone; Tziortzioti, Vassiliki; Topouzis, Stavros; Bauer, Michael; Papapetropoulos, Andreas

    2012-11-01

    Levels of circulating angiopoietin-2 (Ang-2) increase in sepsis, raising the possibility that Ang-2 acts as a modulator in the sepsis cascade. To investigate this, experimental sepsis was induced in male C57BL6 mice by a multidrug-resistant isolate of Pseudomonas aeruginosa; survival was determined along with neutrophil tissue infiltration and release of proinflammatory cytokines. Survival was significantly increased either by pretreatment with recombinant Ang-2 2 h before or treatment with recombinant Ang-2 30 min after bacterial challenge. Likewise, Ang-2 pretreatment protected against sepsis-related death elicited by Escherichia coli; however, Ang-2 failed to provide protection in lipopolysaccharide (LPS)-challenged mice. The survival advantage of Ang-2 in response to P. aeruginosa challenge was lost in tumor necrosis factor (TNF)-deficient mice or neutropenic mice. Infiltration of the liver by neutrophils was elevated in the Ang-2 group compared with saline-treated animals. Serum TNF-α levels were reduced by Ang-2, whereas those of interleukin (IL)-6 and IL-10 remained unchanged. This was accompanied by lower release of TNF-α by stimulated splenocytes. When applied to U937 cells in vitro, heat-killed P. aeruginosa induced the secretion of IL-6 and TNF-α; low levels of exogenous TNF-α synergized with P. aeruginosa. This synergistic effect was abolished after the addition of Ang-2. These results put in evidence a striking protective role of Ang-2 in experimental sepsis evoked by a multidrug-resistant isolate of P. aeruginosa attributed to modulation of TNF-α production and changes in neutrophil migration. The protective role of Ang-2 is shown when whole microorganisms are used and not LPS, suggesting complex interactions with the host immune response. PMID:22859861

  13. Experimental Neuromyelitis Optica Induces a Type I Interferon Signature in the Spinal Cord

    PubMed Central

    Kaufmann, Nathalie; Zeka, Bleranda; Schanda, Kathrin; Fujihara, Kazuo; Illes, Zsolt; Dahle, Charlotte; Reindl, Markus; Lassmann, Hans; Bradl, Monika

    2016-01-01

    Neuromyelitis optica (NMO) is an acute inflammatory disease of the central nervous system (CNS) which predominantly affects spinal cord and optic nerves. Most patients harbor pathogenic autoantibodies, the so-called NMO-IgGs, which are directed against the water channel aquaporin 4 (AQP4) on astrocytes. When these antibodies gain access to the CNS, they mediate astrocyte destruction by complement-dependent and by antibody-dependent cellular cytotoxicity. In contrast to multiple sclerosis (MS) patients who benefit from therapies involving type I interferons (I-IFN), NMO patients typically do not profit from such treatments. How is I-IFN involved in NMO pathogenesis? To address this question, we made gene expression profiles of spinal cords from Lewis rat models of experimental neuromyelitis optica (ENMO) and experimental autoimmune encephalomyelitis (EAE). We found an upregulation of I-IFN signature genes in EAE spinal cords, and a further upregulation of these genes in ENMO. To learn whether the local I-IFN signature is harmful or beneficial, we induced ENMO by transfer of CNS antigen-specific T cells and NMO-IgG, and treated the animals with I-IFN at the very onset of clinical symptoms, when the blood-brain barrier was open. With this treatment regimen, we could amplify possible effects of the I-IFN induced genes on the transmigration of infiltrating cells through the blood brain barrier, and on lesion formation and expansion, but could avoid effects of I-IFN on the differentiation of pathogenic T and B cells in the lymph nodes. We observed that I-IFN treated ENMO rats had spinal cord lesions with fewer T cells, macrophages/activated microglia and activated neutrophils, and less astrocyte damage than their vehicle treated counterparts, suggesting beneficial effects of I-IFN. PMID:26990978

  14. Bacillus cereus Induces Permeability of the Blood Ocular Barrier During Experimental Endophthalmitis

    PubMed Central

    Moyer, A. L.; Ramadan, R. T.; Novosad, B.; Astley, R.; Callegan, M. C.

    2010-01-01

    Purpose The purpose of this study was to determine to what extent blood retina barrier (BRB) permeability occurred during experimental Bacillus cereus endophthalmitis and whether tight junction alterations were involved in permeability. Methods Mice were intravitreally injected with 100 CFU B. cereus and eyes were analyzed at specific times postinfection for permeability to fibrin and albumin, quantitation of intraocular plasma constituent leakage, production of inflammatory cytokines, and alterations in tight junction protein localization and expression at the level of the RPE. Results B. cereus-induced leakage of albumin and fibrin into the aqueous and vitreous humor by 8 h postinfection. BRB permeability occurred as early as 4 h and increased 13.30-fold compared to uninfected controls by 8 h. Production of proinflammatory cytokines IL-6, MIP-1α, IL-1β, and KC increased over the course of infection. In the retina, ZO-1 disruption begins by 4 h, followed by decreasing occludin and ZO-1 expression at 4 and 8 h, respectively. Tubulin condensation and RPE65 degradation occurred by 12 h. A quorum sensing mutant B. cereus strain caused BRB permeability comparable to that of wild-type B. cereus. Both wild-type and mutant B. cereus sterile supernatants induced blood ocular barrier permeability similarly to that of wild-type infection. Conclusions These results indicate that BRB permeability occurs during the early stages of experimental B. cereus endophthalmitis, beginning as early as 4 h postinfection. Disruption of tight junctions at the level of the RPE may contribute to barrier breakdown. Quorum-sensing dependent factors may not significantly contribute to BRB permeability. PMID:19264886

  15. Experimental Neuromyelitis Optica Induces a Type I Interferon Signature in the Spinal Cord.

    PubMed

    Oji, Satoru; Nicolussi, Eva-Maria; Kaufmann, Nathalie; Zeka, Bleranda; Schanda, Kathrin; Fujihara, Kazuo; Illes, Zsolt; Dahle, Charlotte; Reindl, Markus; Lassmann, Hans; Bradl, Monika

    2016-01-01

    Neuromyelitis optica (NMO) is an acute inflammatory disease of the central nervous system (CNS) which predominantly affects spinal cord and optic nerves. Most patients harbor pathogenic autoantibodies, the so-called NMO-IgGs, which are directed against the water channel aquaporin 4 (AQP4) on astrocytes. When these antibodies gain access to the CNS, they mediate astrocyte destruction by complement-dependent and by antibody-dependent cellular cytotoxicity. In contrast to multiple sclerosis (MS) patients who benefit from therapies involving type I interferons (I-IFN), NMO patients typically do not profit from such treatments. How is I-IFN involved in NMO pathogenesis? To address this question, we made gene expression profiles of spinal cords from Lewis rat models of experimental neuromyelitis optica (ENMO) and experimental autoimmune encephalomyelitis (EAE). We found an upregulation of I-IFN signature genes in EAE spinal cords, and a further upregulation of these genes in ENMO. To learn whether the local I-IFN signature is harmful or beneficial, we induced ENMO by transfer of CNS antigen-specific T cells and NMO-IgG, and treated the animals with I-IFN at the very onset of clinical symptoms, when the blood-brain barrier was open. With this treatment regimen, we could amplify possible effects of the I-IFN induced genes on the transmigration of infiltrating cells through the blood brain barrier, and on lesion formation and expansion, but could avoid effects of I-IFN on the differentiation of pathogenic T and B cells in the lymph nodes. We observed that I-IFN treated ENMO rats had spinal cord lesions with fewer T cells, macrophages/activated microglia and activated neutrophils, and less astrocyte damage than their vehicle treated counterparts, suggesting beneficial effects of I-IFN. PMID:26990978

  16. Chronic effort dyspnea explained by lung function tests and by HRCT and CRX radiographic patterns in COPD: a post-hoc analysis in 51 patients.

    PubMed

    Giuntini, Carlo; Camiciottoli, Gianna; Maluccio, Nazzarena Maria; Mariani, Laura; Lavorini, Federico; Pistolesi, Massimo

    2007-09-01

    This paper is a post-hoc analysis of a previous study performed to investigate the relationship between computerized tomography (CT) and lung function in 51 outpatients with mild-to-moderate COPD. We studied whether changes in lung function and radiographic patterns may help to explain dyspnea, the most disturbing symptom in patients with COPD. The Medical Research Council (MRC) dyspnea scale shows, by univariate analysis, a similar strength of association to CT expiratory lung density and to DL(CO), a functional index of lung parenchymal loss. The MRC dyspnea scale shows a somewhat less strength of association with a small vertical heart on plain chest films. In multivariate analysis, the model with the strongest association to the MRC dyspnea scale (r = 0.76, p < 0.0001) contains 4 explanatory variables (DL(CO), FRC, PaCO(2), and radiographic pattern of pulmonary hypertension). We suggest that diffusing capacity reflects the emphysematous component of hyperinflation, associated by definition with destruction of terminal airspace walls, as distinct from the air trapping component, which is ascribed to airway obstruction and associated with FRC. PaCO(2) mainly reflects the ventilatory components, i.e., ventilatory drive and ventilatory constraints, of pulmonary gas exchange in COPD, while radiographic pattern of pulmonary hypertension likely reflects hypoxic vascular changes, which depend mainly on ventilation/perfusion mismatch and give rise to pulmonary arterial hypertension that may contribute per se to dyspnea. In conclusion, our analysis points out that chronic effort dyspnea variance may account for up to 58% (r(2) = 0.58) by lung function tests and radiographic patterns. Thus, about 42% of the MRC dyspnea variance remains unexplained by this model. On the other hand, dyspnea ascertainment is dependent on subjective behavior and evaluation and in tests is influenced by individual performance and perception. For example in the 6-minute walk test, a similar or

  17. Extract of Sesbania grandiflora Ameliorates Hyperglycemia in High Fat Diet-Streptozotocin Induced Experimental Diabetes Mellitus

    PubMed Central

    Panigrahi, Ghanshyam; Panda, Chhayakanta; Patra, Arjun

    2016-01-01

    Background. Sesbania grandiflora has been traditionally used as antidiabetic, antioxidant, antipyretic, and expectorant and in the management of various ailments. Materials and Methods. The study evaluates the antidiabetic activity of methanolic extract of Sesbania grandiflora (MESG) in type 2 diabetic rats induced by low dose streptozotocine and high fat diet. Diabetic rats were given vehicle, MESG (200 and 400 mg/kg, p.o.), and the standard drug, metformin (10 mg/kg), for 28 days. During the experimental period, body weight, abdominal girth, food intake, fasting serum glucose, urine analyses were measured. Insulin tolerance test was carried out on 25th day of drug treatment period. Serum analyses for lipid profile and SGOT and SGPT and serums creatinine, urea, protein, SOD, and MDA were also carried out. At the end of the experiment, animals were euthanized, the liver and pancreas were immediately dissected out, and the ratio of pancreas to body weight and hepatic glycogen were calculated. Results. MESG (200 and 400 mg/kg, p.o.) induced significant reduction (P < 0.05) of raised blood glucose levels in diabetic rats and also restored other parameters to normal level. Conclusion. Therefore, it is concluded that MESG has potential antihyperglycemic and antihyperlipemic activities and alleviate insulin resistance conditions. PMID:27313954

  18. Plasmepsin 4-Deficient Plasmodium berghei Are Virulence Attenuated and Induce Protective Immunity against Experimental Malaria

    PubMed Central

    Spaccapelo, Roberta; Janse, Chris J.; Caterbi, Sara; Franke-Fayard, Blandine; Bonilla, J. Alfredo; Syphard, Luke M.; Di Cristina, Manlio; Dottorini, Tania; Savarino, Andrea; Cassone, Antonio; Bistoni, Francesco; Waters, Andrew P.; Dame, John B.; Crisanti, Andrea

    2010-01-01

    Plasmodium parasites lacking plasmepsin 4 (PM4), an aspartic protease that functions in the lysosomal compartment and contributes to hemoglobin digestion, have only a modest decrease in the asexual blood-stage growth rate; however, PM4 deficiency in the rodent malaria parasite Plasmodium berghei results in significantly less virulence than that for the parental parasite. P. berghei Δpm4 parasites failed to induce experimental cerebral malaria (ECM) in ECM-susceptible mice, and ECM-resistant mice were able to clear infections. Furthermore, after a single infection, all convalescent mice were protected against subsequent parasite challenge for at least 1 year. Real-time in vivo parasite imaging and splenectomy experiments demonstrated that protective immunity acted through antibody-mediated parasite clearance in the spleen. This work demonstrates, for the first time, that a single Plasmodium gene disruption can generate virulence-attenuated parasites that do not induce cerebral complications and, moreover, are able to stimulate strong protective immunity against subsequent challenge with wild-type parasites. Parasite blood-stage attenuation should help identify protective immune responses against malaria, unravel parasite-derived factors involved in malarial pathologies, such as cerebral malaria, and potentially pave the way for blood-stage whole organism vaccines. PMID:20019192

  19. Foraminiferal survival after long-term in situ experimentally induced anoxia

    NASA Astrophysics Data System (ADS)

    Langlet, D.; Geslin, E.; Baal, C.; Metzger, E.; Lejzerowicz, F.; Riedel, B.; Zuschin, M.; Pawlowski, J.; Stachowitsch, M.; Jorissen, F. J.

    2013-11-01

    Anoxia was successfully induced in four benthic chambers installed at 24 m depth on the northern Adriatic seafloor from 9 days to 10 months. To accurately determine whether benthic foraminifera can survive experimentally induced prolonged anoxia, the CellTrackerTM Green method was applied and calcareous and agglutinated foraminifera were analyzed. Numerous individuals were found living at all sampling times and at all sampling depths (to 5 cm), supported by a ribosomal RNA analysis that revealed that certain benthic foraminifera were active after 10 months of anoxia. The results show that benthic foraminifera can survive up to 10 months of anoxia with co-occurring hydrogen sulfides. However, foraminiferal standing stocks decrease with sampling time in an irregular manner. A large difference in standing stock between two cores sampled under initial conditions indicates the presence of a large spatial heterogeneity of the foraminiferal faunas. An unexpected increase in standing stocks after one month is tentatively interpreted as a reaction to increased food availability due to the massive mortality of infaunal macrofaunal organisms. After this, standing stocks decrease again in cores sampled after 2 months of anoxia to then attain a minimum in the cores sampled after 10 months. We speculate that the trend of overall decrease of standing stocks is not due to the adverse effects of anoxia and hydrogen sulfides but rather due to a continuous diminution of labile organic matter.

  20. Extract of Sesbania grandiflora Ameliorates Hyperglycemia in High Fat Diet-Streptozotocin Induced Experimental Diabetes Mellitus.

    PubMed

    Panigrahi, Ghanshyam; Panda, Chhayakanta; Patra, Arjun

    2016-01-01

    Background. Sesbania grandiflora has been traditionally used as antidiabetic, antioxidant, antipyretic, and expectorant and in the management of various ailments. Materials and Methods. The study evaluates the antidiabetic activity of methanolic extract of Sesbania grandiflora (MESG) in type 2 diabetic rats induced by low dose streptozotocine and high fat diet. Diabetic rats were given vehicle, MESG (200 and 400 mg/kg, p.o.), and the standard drug, metformin (10 mg/kg), for 28 days. During the experimental period, body weight, abdominal girth, food intake, fasting serum glucose, urine analyses were measured. Insulin tolerance test was carried out on 25th day of drug treatment period. Serum analyses for lipid profile and SGOT and SGPT and serums creatinine, urea, protein, SOD, and MDA were also carried out. At the end of the experiment, animals were euthanized, the liver and pancreas were immediately dissected out, and the ratio of pancreas to body weight and hepatic glycogen were calculated. Results. MESG (200 and 400 mg/kg, p.o.) induced significant reduction (P < 0.05) of raised blood glucose levels in diabetic rats and also restored other parameters to normal level. Conclusion. Therefore, it is concluded that MESG has potential antihyperglycemic and antihyperlipemic activities and alleviate insulin resistance conditions. PMID:27313954

  1. Low-Dose IL-2 Induces Regulatory T Cell-Mediated Control of Experimental Food Allergy.

    PubMed

    Bonnet, Benjamin; Vigneron, James; Levacher, Béatrice; Vazquez, Thomas; Pitoiset, Fabien; Brimaud, Faustine; Churlaud, Guillaume; Klatzmann, David; Bellier, Bertrand

    2016-07-01

    Regulatory T cells (Tregs) are pivotal for maintenance of immune self-tolerance and also regulate immune responses to exogenous Ags, including allergens. Both decreased Treg number and function have been reported in allergic patients, offering new therapeutic perspectives. We previously demonstrated that Tregs can be selectively expanded and activated by low doses of IL-2 (ld-IL-2) inducing immunoregulation without immunosuppression and established its protective effect in autoimmune diseases. In this study, we evaluated the ability of ld-IL-2 to control allergy in an experimental model of food allergy. Ld-IL-2 induced Treg expansion and activation that elicited protection against clinical manifestations of food allergy in two mouse models with OVA and peanut. This clinical effect was lost in Treg-depleted mice, demonstrating the major contribution of Tregs in ld-IL-2 efficacy. Mechanistic studies further indicated that protection from allergy could be explained by a Treg-dependent local modification of the Th1/Th2 balance and an inhibition of mast cell recruitment and activation. Preventive and therapeutic effects of ld-IL-2 were observed over a 7-mo-period, highlighting its long-term efficacy. This study demonstrated that ld-IL-2 is efficient to prevent and to treat allergic immune responses, and thus represents a promising therapeutic strategy for managing allergic diseases. PMID:27259854

  2. Experimental Protoporphyria: Effect of Bile Acids on Liver Damage Induced by Griseofulvin

    PubMed Central

    Martinez, María del Carmen; Ruspini, Silvina Fernanda; Afonso, Susana Graciela; Meiss, Roberto; Buzaleh, Ana Maria

    2015-01-01

    The effect of bile acids administration to an experimental mice model of Protoporphyria produced by griseofulvin (Gris) was investigated. The aim was to assess whether porphyrin excretion could be accelerated by bile acids treatment in an attempt to diminish liver damage induced by Gris. Liver damage markers, heme metabolism, and oxidative stress parameters were analyzed in mice treated with Gris and deoxycholic (DXA), dehydrocholic (DHA), chenodeoxycholic, or ursodeoxycholic (URSO). The administration of Gris alone increased the activities of glutathione reductase (GRed), superoxide dismutase (SOD), alkaline phosphatase (AP), gamma glutamyl transpeptidase (GGT), and glutathione-S-transferase (GST), as well as total porphyrins, glutathione (GSH), and cytochrome P450 (CYP) levels in liver. Among the bile acids studied, DXA and DHA increased PROTO IX excretion, DXA also abolished the action of Gris, reducing lipid peroxidation and hepatic GSH and CYP levels, and the activities of GGT, AP, SOD, and GST returned to control values. However, porphyrin accumulation was not prevented by URSO; instead this bile acid reduced ALA-S and the antioxidant defense enzymes system activities. In conclusion, we postulate that DXA acid would be more effective to prevent liver damage induced by Gris. PMID:25945334

  3. Critical role of activation induced cytidine deaminase in experimental autoimmune encephalomyelitis.

    PubMed

    Sun, Yonglian; Peng, Ivan; Senger, Kate; Hamidzadeh, Kajal; Reichelt, Mike; Baca, Miriam; Yeh, Ronald; Lorenzo, Maria N; Sebrell, Andrew; Dela Cruz, Christopher; Tam, Lucinda; Corpuz, Racquel; Wu, Jiansheng; Sai, Tao; Roose-Girma, Merone; Warming, Søren; Balazs, Mercedesz; Gonzalez, Lino C; Caplazi, Patrick; Martin, Flavius; Devoss, Jason; Zarrin, Ali A

    2013-03-01

    Multiple Sclerosis (MS) is a neurodegenerative autoimmune disorder caused by chronic inflammation and demyelination within the central nervous system (CNS). Clinical studies in MS patients have demonstrated efficacy with B cell targeted therapies such as anti-CD20. However, the exact role that B cells play in the disease process is unclear. Activation Induced cytidine deaminase (AID) is an essential enzyme for the processes of antibody affinity maturation and isotype switching. To evaluate the impact of affinity maturation and isotype switching, we have interrogated the effect of AID-deficiency in an animal model of MS. Here, we show that the severity of experimental autoimmune encephalomyelitis (EAE) induced by the extracellular domain of human myelin oligodendrocyte glycoprotein (MOG1-125) is significantly reduced in Aicda deficient mice, which, unlike wild-type mice, lack serum IgG to myelin associated antigens. MOG specific T cell responses are comparable between wild-type and Aicda knockout mice suggesting an active role for antigen experienced B cells. Thus affinity maturation and/or class switching are critical processes in the pathogenesis of EAE. PMID:23167594

  4. Critical role of activation induced cytidine deaminase in Experimental Autoimmune Encephalomyelitis

    PubMed Central

    2013-01-01

    Multiple Sclerosis (MS) is a neurodegenerative autoimmune disorder caused by chronic inflammation and demyelination within the central nervous system (CNS). Clinical studies in MS patients have demonstrated efficacy with B cell targeted therapies such as anti-CD20. However, the exact role that B cells play in the disease process is unclear. Activation Induced cytidine deaminase (AID) is an essential enzyme for the processes of antibody affinity maturation and isotype switching. To evaluate the impact of affinity maturation and isotype switching, we have interrogated the effect of AID-deficiency in an animal model of MS. Here, we show that the severity of experimental autoimmune encephalomyelitis (EAE) induced by the extracellular domain of human myelin oligodendrocyte glycoprotein (MOG1-125) is significantly reduced in Aicda deficient mice, which, unlike wild-type mice, lack serum IgG to myelin associated antigens. MOG specific T cell responses are comparable between wild-type and Aicda knockout mice suggesting an active role for antigen experienced B cells. Thus affinity maturation and/or class switching are critical processes in the pathogenesis of EAE. PMID:23167594

  5. Exploring the electron density in plasma induced by EUV radiation: I. Experimental study in hydrogen

    NASA Astrophysics Data System (ADS)

    van der Horst, R. M.; Beckers, J.; Osorio, E. A.; Astakhov, D. I.; Goedheer, W. J.; Lee, C. J.; Ivanov, V. V.; Krivtsum, V. M.; Koshelev, K. N.; Lopaev, D. V.; Bijkerk, F.; Banine, V. Y.

    2016-04-01

    Plasmas induced by EUV radiation are unique since they are created without the need of any discharge. Moreover, it is essential to characterize these plasmas to understand and predict their long term impact on highly delicate optics in EUV lithography tools. In this paper we study plasmas induced by 13.5 nm EUV radiation in hydrogen gas. The electron density is measured temporally resolved using a non-invasive technique known as microwave cavity resonance spectroscopy. The influence of the EUV pulse energy and gas pressure on the temporal evolution of the electron density has been explored over a parameter range relevant for industry. Our experimental results show that the maximum electron density is in the order of 1014 m-3 and depends linearly on the EUV pulse energy. Furthermore, the maximum electron density depends quadratically on the pressure; the linear term is caused by photoionization and the quadratic term by subsequent electron impact ionization. The decay of the plasma is governed by ambipolar diffusion and, hence, becomes slower at elevated pressures. Similarities and differences of the same processes in argon are highlighted in this paper.

  6. Effects of losartan on experimental varicocele-induced testicular germ cell apoptosis.

    PubMed

    Bolat, D; Oltulu, F; Uysal, A; Kose, T; Gunlusoy, B; Yigitturk, G; Turk, N S; Turan, T

    2016-09-01

    To investigate the potential protective effects of losartan on varicocele-induced germ cell apoptosis, 24 adult male Sprague Dawley rats were divided into three groups: a sham operation was performed in SHAM group, and experimental left varicocele was created in VAR and VAR + LOS groups. Additionally, in VAR + LOS group, losartan was administered for 30 days starting on the day of surgery. At the end of 30 days, all animals were sacrificed and left orchiectomy was performed. Testicular injury and spermatogenesis were evaluated according to Johnsen scoring system. To assess the nitrosative stress, immunohistochemical staining for endothelial nitric oxide synthase was used and evaluated by H-score and apoptotic index (AI) of germ cells was analysed by TUNEL method. A significant decrease in the mean Johnsen score (JS) was observed in VAR group compared with SHAM (p < .001). The mean H-score and AI were significantly higher in VAR group compared with SHAM (p < .001). After losartan administration, mean JS was significantly increased (p < .001) and mean H-score and AI were significantly decreased compared with VAR group (p < .001 and .01, respectively). Findings of this suggest that losartan acts as a potent protective agent against varicocele-induced germ cell apoptosis. PMID:27373273

  7. Prevention of chemically induced diabetes mellitus in experimental animals by virgin argan oil.

    PubMed

    Bellahcen, Said; Mekhfi, Hassane; Ziyyat, Abderrahim; Legssyer, Abdelkhaleq; Hakkou, Abdelkader; Aziz, Mohammed; Bnouham, Mohamed

    2012-02-01

    The argan tree plays an important socioeconomic and ecologic role in South Morocco. Moreover, there is much evidence for the beneficial effects of virgin argan oil (VAO) on human health. Thus, this study investigated whether administering VAO to rats can prevent the development of diabetes. VAO extracted by a traditional method from the almonds of Argania spinosa (2 mL/kg) was administered orally (for 7 consecutive days) to rats before and during intraperitoneal alloxan administration (75 mg/kg for 5 consecutive days). An alloxan diabetic-induced untreated group and treated by table oil were used as control groups. Body mass, blood glucose and hepatic glycogen were evaluated. In the present study, subchronic treatment with VAO at a dose of 2 mL/kg, before the experimental induction of diabetes, prevented the body mass loss, induced a significant reduction of blood glucose and a significant increase of hepatic glycogen level (p < 0.001) compared with the untreated diabetic group. In conclusion, the present study shows that argan oil should be further investigated in a human study to clarify its possible role in reducing weight loss in diabetics, and even in inhibiting the development or progression of diabetes. This antidiabetic effect could be due to the richness of VAO in tocopherols, phenolic compounds and unsaturated fatty acids. PMID:21584872

  8. Antistressor activity of Ocimum sanctum (Tulsi) against experimentally induced oxidative stress in rabbits.

    PubMed

    Jyoti, S; Satendra, S; Sushma, S; Anjana, T; Shashi, S

    2007-01-01

    Fresh leaves of Ocimum sanctum (O. sanctum) were evaluated for antistress activity against experimentally induced oxidative stress in albino rabbits. Animals of the test group received supplementation of 2 g fresh leaves of O. sanctum per rabbit for 30 days. Anemic hypoxia was induced chemically by injecting the rabbits with 15 mg sodium nitrite per 100 g body weight intraperitoneally. Results indicated that O. sanctum administration blunted the changes in cardiorespiratory (BP, HR, RR) parameters in response to stress. A significant (p < 0.01) decrease in blood sugar level was observed after 30 days of dietary supplementation of O. sanctum leaves. Significant increase (p < 0.05) in the levels of enzymatic (superoxide dismutase) and nonenzymatic (reduced glutathione) antioxidants was observed in the test group after the treatment with O. sanctum. Oxidative stress led to a lesser depletion of reduced glutathione (28.80%) and plasma superoxide dismutase (23.04%) in O. sanctum-treated rabbits. The results of this study suggest that the potential antistressor activity of O. sanctum is partly attributable to its antioxidant properties. PMID:17922070

  9. Role of vascular endothelial growth factor signaling in Schistosoma-induced experimental pulmonary hypertension

    PubMed Central

    2014-01-01

    Abstract There is significant evidence that Th2 (T helper 2)-mediated inflammation supports the pathogenesis of both human and experimental animal models of pulmonary hypertension (PH). A key immune regulator is vascular endothelial growth factor (VEGF), which is produced by Th2 inflammation and can itself contribute to Th2 pulmonary responses. In this study, we interrogated the role of VEGF signaling in a murine model of schistosomiasis-induced PH with a phenotype of significant intrapulmonary Th2 inflammation, vascular remodeling, and elevated right ventricular pressures. We found that VEGF receptor blockade partially suppressed the levels of the Th2 inflammatory cytokines interleukin (IL)-4 and IL-13 in both the lung and the liver after Schistosoma mansoni exposure and suppressed pulmonary vascular remodeling. These findings suggest that VEGF positively contributes to schistosomiasis-induced vascular inflammation and remodeling, and they also provide evidence for a VEGF-dependent signaling pathway necessary for pulmonary vascular remodeling and inflammation in this model. PMID:25006448

  10. Antitussive effect of naringin on experimentally induced cough in Guinea pigs.

    PubMed

    Gao, Sen; Li, Peibo; Yang, Hongliang; Fang, Siqi; Su, Weiwei

    2011-01-01

    The mechanism of action of naringin has been investigated in different models of experimentally induced cough in guinea pigs. In contrast to codeine phosphate (6 mg/kg, intravenous administration [i. v.]), naringin (15, 30, and 60 mg/kg, i. v.) had no central antitussive effect on cough elicited by electrical stimulation of the superior laryngeal nerve. Naringin (0.5, 1.0, and 2.0 µmol) could not prevent the cough reflex induced by stimulation of the trachea after intracerebroventricular injection (i. c. v.), while codeine phosphate (0.5 µmol) was highly effective. Further characterizing the peripheral mechanism of naringin, we found that its effect (50 mg/kg, i. v.) was not affected by the depletion of sensory neuropeptides, whereas levodropropizine (10 mg/kg, i. v.) lost its capacity to prevent cough in the capsaicin-desensitized guinea pig. Furthermore, pretreatment with glibenclamide (10 mg/kg, intraperitoneal [i. p.]) significantly reduced the antitussive effect of pinacidil (5 mg/kg, subcutaneous [s. c.]), but could not antagonize the antitussive effect of naringin (30 mg/kg, s. c.). Our present results suggest that naringin is not a central antitussive drug. And naringin does not exert its peripheral antitussive effect through either the sensory neuropeptides system or the modulation of ATP-sensitive K (+) channels. PMID:20645246

  11. Tauroursodeoxycholate improves 2,4,6-trinitrobenzenesulfonic acid-induced experimental acute ulcerative colitis in mice.

    PubMed

    Yang, Yang; He, Jiao; Suo, Yuan; Zheng, Zongwei; Wang, Jingjing; Lv, Le; Huo, Chuanchuan; Wang, Ziye; Li, Jing; Sun, Wenji; Zhang, Yongmin

    2016-07-01

    Ulcerative colitis is a chronic nonspecific inflammatory disease of unknown cause. The aim of this study was to evaluate the anti-inflammatory effect of tauroursodeoxycholate in 2, 4, 6-trinitrobenzenesulfonic acid-induced experimental colitis in mice. After the induction of colitis for 24h, the mice were administrated orally with tauroursodeoxycholate (20, 40 and 60mg/kg) and sulfasalazine (500mg/kg) by gavage for 7 consecutive days. The inhibition effects were evaluated by the body of weight change, survival rate, macroscopical and histological evaluations. Besides, myeloperoxidase (MPO) activity, interleukin (IL)-1β, interferon (IFN)-γ and tumour necrosis factor-α (TNF-α) in colon tissue were also determined by enzyme-linked immunosorbent assay. Treatment with different doses of tauroursodeoxycholate (20, 40 and 60mg/kg) significantly improved the body weight change, decreased the macroscopic and histopathological scores. Compared with the model group, the accumulation of MPO activity, the colonic tissue levels of IL-1β, IFN-γ and TNF-α were significantly reduced in the tauroursodeoxycholate treated groups. Moreover, tauroursodeoxycholate assuaged the symptoms of colitis. These results suggested that tauroursodeoxycholate has an anti-inflammatory effect in TNBS-induced ulcerative colitis in mice. PMID:27179450

  12. Induced current electrical impedance tomography system: experimental results and numerical simulations.

    PubMed

    Zlochiver, Sharon; Radai, M Michal; Abboud, Shimon; Rosenfeld, Moshe; Dong, Xiu-Zhen; Liu, Rui-Gang; You, Fu-Sheng; Xiang, Hai-Yan; Shi, Xue-Tao

    2004-02-01

    In electrical impedance tomography (EIT), measurements of developed surface potentials due to applied currents are used for the reconstruction of the conductivity distribution. Practical implementation of EIT systems is known to be problematic due to the high sensitivity to noise of such systems, leading to a poor imaging quality. In the present study, the performance of an induced current EIT (ICEIT) system, where eddy current is applied using magnetic induction, was studied by comparing the voltage measurements to simulated data, and examining the imaging quality with respect to simulated reconstructions for several phantom configurations. A 3-coil, 32-electrode ICEIT system was built, and an iterative modified Newton-Raphson algorithm was developed for the solution of the inverse problem. The RMS norm between the simulated and the experimental voltages was found to be 0.08 +/- 0.05 mV (<3%). Two regularization methods were implemented and compared: the Marquardt regularization and the Laplacian regularization (a bounded second-derivative regularization). While the Laplacian regularization method was found to be preferred for simulated data, it resulted in distinctive spatial artifacts for measured data. The experimental reconstructed images were found to be indicative of the angular positioning of the conductivity perturbations, though the radial sensitivity was low, especially when using the Marquardt regularization method. PMID:15005319

  13. Application of metabonomics on an experimental model of fibrosis and cirrhosis induced by thioacetamide in rats

    SciTech Connect

    Constantinou, Maria A.; Theocharis, Stamatios E.; Mikros, Emmanuel . E-mail: mikros@pharm.uoa.gr

    2007-01-01

    Metabonomics has already been used to discriminate different pathological states in biological fields. The metabolic profiles of chronic experimental fibrosis and cirrhosis induction in rats were investigated using {sup 1}H NMR spectroscopy of liver extracts and serum combined with pattern recognition techniques. Rats were continuously administered with thioacetamide (TAA) in the drinking water (300 mg TAA/L), and sacrificed on 1st, 2nd, and 3rd month of treatment. {sup 1}H NMR spectra of aqueous and lipid liver extracts, together with serum were subjected to Principal Component Analysis (PCA). Liver portions were also subjected to histopathological examination and biochemical determination of malondialdehyde (MDA). Liver fibrosis and cirrhosis were progressively induced in TAA-treated rats, verified by the histopathological examination and the alterations of MDA levels. TAA administration revealed a number of changes in the {sup 1}H NMR spectra compared to control samples. The performance of PCA in liver extracts and serum, discriminated the control samples from the fibrotic and cirrhotic ones. Metabolic alterations revealed in NMR spectra during experimental liver fibrosis and cirrhosis induction, characterize the stage of fibrosis and could be illustrated by subsequent PCA of the spectra. Additionally, the PCA plots of the serum samples presented marked clustering during fibrosis progression and could be extended in clinical diagnosis for the management of cirrhotic patients.

  14. Experimentally Induced Pulpal Lesion and Substance P Expression: Effect of Ketoprofen—A Preliminary Study

    PubMed Central

    Abbate, Gian Marco; Sacerdote, Paola; Amodeo, Giada; Mangano, Alessandro; Levrini, Luca

    2016-01-01

    Objectives. To evaluate substance P (SP) and the effect of ketoprofen administration, a nonsteroidal anti-inflammatory drug (NSAID), on SP in the pulp of upper third molars with experimentally induced pulpal lesion. Materials and Methods. A sample of 20 young systemically healthy adults of both sexes, nonsmokers, with a healthy upper third molar to extract for orthodontic purposes, was selected. Prior to the procedure, an inflammatory process was generated by mechanical exposure of the pulp. After 15 minutes, the pulp was collected using a sterile barbed broach. SP levels were determined by using a commercially available enzyme immunoassay (ELISA) kit. The subjects were randomly divided into two groups: group 1 received a dose of ketoprofen 30 minutes prior to the experimental procedure. The subjects of group 2 did not receive any kind of drug administration. The patients were asked to complete a diary on the postoperative pain. Results. No statistically significant difference could be detected in SP expression between the two groups. In group 1, pain manifestation was significantly delayed in comparison with group 2. Conclusions. Preventive administration of ketoprofen did not significantly affect the pulpal levels of SP but resulted in a significantly postponed manifestation of pain after extraction. PMID:27034673

  15. Naturally occurring and experimentally induced castor bean (Ricinus communis) poisoning in ducks

    USGS Publications Warehouse

    Jensen, W.I.; Allen, J.P.

    1981-01-01

    Castor bean (Ricinus communis) poisoning accounted for the death of several thousand ducks in the Texas panhandle in the fall and winter months of 1969-1971. Signs of intoxication resembled those of botulism, except for mucoid, blood-tinged excreta. The most common lesions were severe fatty change in the liver, widely distributed internal petechial hemorrhages or ecchymoses, and catarrhal enteritis. Nearly intact castor beans were found in the stomach of one duck during field necropsy. Fragments of seed coat resembling castor bean were found in the stomachs of 10 of 14 ducks examined in the laboratory. Clinical signs and postmortem lesions observed in wild ducks were induced experimentally in mallards (Anas platyrhynchos) by force-feeding intact castor beans. Toxicity titrations were erratic, but the LD50 appeared to be between three and four seeds. The mouse toxicity test, used to detect Clostridium botulinum toxin in the blood serum of intoxicated ducks, was negative in every case. Hemagglutination and precipitin tests generally failed to detect castor bean in extracts of excreta or intestinal contents of experimentally intoxicated ducks.

  16. Acid-induced changes in DOC quality in an experimental whole-lake manipulation

    SciTech Connect

    Donahue, W.F.; Schindler, D.W.; Page, S.J.; Stainton, M.P.

    1998-10-01

    Fluorescence analyses of archived water samples were used to typify dissolved organic carbon (DOC) quality in experimentally acidified lakes and reference lakes at the Experimental Lakes Area, in northwestern Ontario. Carbon-specific DOC fluorescence (CSF) during peak acidification was 40--50% of that for a high-DOC reference lake and similar to a low-DOC reference lake. Reference lakes showed similar but smaller decreases in CSF during several years of prolonged drought in the late 1980s. During the 1990s, recovery from acidification resulted in increased CSF, whereas reference lakes remained unchanged during the same time period. In addition to causing decreased [DOC], acidification causes changes in fluorescence-peak geometry that indicate a switch in DOC quality from allochthonous to autochthonous-like during acidification. The acid-induced change in DOC quality was likely due to increased chemical oxidation or precipitation of the UV-absorbent aromatic portions of allochthonous DOC molecules, leaving more UV-transparent aliphatic chains. The change in the nature of DOC following acidification and drought may have an important role in physical, biological, and chemical processes within these lakes. With recovery from acidification, DOC quality has also recovered.

  17. Experimental investigation of flow-induced vibration interference between two circular cylinders

    NASA Astrophysics Data System (ADS)

    Assi, G. R. S.; Meneghini, J. R.; Aranha, J. A. P.; Bearman, P. W.; Casaprima, E.

    2006-08-01

    This paper presents experimental results concerning flow-induced oscillations of circular cylinders arranged in tandem. New measurements on the dynamic response oscillations of an isolated cylinder and flow interference of two cylinders are shown. Preliminary flow visualization employing a PIV system is also shown. The models are mounted on an elastic base fitted with flexor blades and instrumented with strain gauges. The base is fixed on the test-section of a water channel facility. The flexor blades possess a low-damping characteristic (ζ≃0.008 0.0109) and they are free to oscillate only in the cross-flow direction. The Reynolds number of the experiments is from 3000 to 13000, and reduced velocities, based on natural frequency in still water, vary up to 12. The interference phenomenon on VIV is investigated by conducting experiments in which the upstream cylinder is maintained fixed and the downstream one is mounted on the elastic base. The results for an isolated cylinder are in accordance with other measurements found in the literature for m≃2 and 8. For the tandem arrangement and m≃2, the trailing cylinder oscillation presents what previous researchers have termed interference galloping behaviour for a centre-to-centre gap spacing ranging from 2D to 5.6D. These initial results validate the experimental set-up and lead the way for future work, including tandem, staggered and side-by-side arrangements with the two cylinders free to move.

  18. Prediction of Symptom Change in Placebo Versus No-Treatment Group in Experimentally Induced Motion Sickness.

    PubMed

    Horing, Bjoern; Weimer, Katja; Muth, Eric R; Enck, Paul

    2015-09-01

    The long-standing question of who responds to placebo and who does not is of great theoretical and clinical relevance and has received increasing attention in recent years. We therefore performed a post hoc analysis of one of our previously published studies on placebo responses (PRs). In the analysis, fourteen potential predictors for the PR on experimentally induced motion sickness in 32 healthy volunteers were explored using moderated multiple regression. Generalized self-efficacy, generalized self, internal locus of control and cognitive flexibility were significantly associated with symptom improvement in the placebo group, as compared to the untreated control group. Notably, the directions of the associations were such that the "unfavorable" side of the constructs (e.g. low self-efficacy) predicted a higher PR. Instead, the "favorable" side predicted symptom improvement in the control group. Results fit well with prior research into psychological influences on motion sickness. Although PRs in motion sickness are not well established, it is suggested to include the identified constructs in future research involving motion sickness-related symptoms such as nausea and vertigo. Concerning PRs in general, the results may have implications for clinical as well as experimental research on other symptoms and disorders, such as pain or depression. PMID:25912825

  19. Experimentally Induced Pulpal Lesion and Substance P Expression: Effect of Ketoprofen-A Preliminary Study.

    PubMed

    Abbate, Gian Marco; Sacerdote, Paola; Amodeo, Giada; Mangano, Alessandro; Levrini, Luca

    2016-01-01

    Objectives. To evaluate substance P (SP) and the effect of ketoprofen administration, a nonsteroidal anti-inflammatory drug (NSAID), on SP in the pulp of upper third molars with experimentally induced pulpal lesion. Materials and Methods. A sample of 20 young systemically healthy adults of both sexes, nonsmokers, with a healthy upper third molar to extract for orthodontic purposes, was selected. Prior to the procedure, an inflammatory process was generated by mechanical exposure of the pulp. After 15 minutes, the pulp was collected using a sterile barbed broach. SP levels were determined by using a commercially available enzyme immunoassay (ELISA) kit. The subjects were randomly divided into two groups: group 1 received a dose of ketoprofen 30 minutes prior to the experimental procedure. The subjects of group 2 did not receive any kind of drug administration. The patients were asked to complete a diary on the postoperative pain. Results. No statistically significant difference could be detected in SP expression between the two groups. In group 1, pain manifestation was significantly delayed in comparison with group 2. Conclusions. Preventive administration of ketoprofen did not significantly affect the pulpal levels of SP but resulted in a significantly postponed manifestation of pain after extraction. PMID:27034673

  20. Experimentally induced life-history evolution in a killifish in response to the introduction of guppies.

    PubMed

    Walsh, Matthew R; Reznick, David N

    2011-04-01

    Life-history theory predicts that increased predation on juvenile age/size-classes favors delayed maturation and decreased reproductive investment. Although this theory has received correlative support, experimental tests in nature are rare. In 1976 and 1981, guppies (Poecilia reticulata) were transplanted into localities that previously only contained a killifish, Rivulus hartii. This situation presents an opportunity to experimentally test this life-history prediction because guppies prey upon young Rivulus. We evaluated the response to selection in Rivulus by measuring phenotypic and genotypic divergence between introduction and upstream "control" localities that lack guppies. Contrary to expectations, Rivulus from the introduction sites evolved earlier maturation and increased reproductive investment within 25 years. Such evolutionary changes parallel previous investigations on natural communities of Rivulus, but do not comply with predictions of age/size-specific theory. Guppies also caused reduced densities and increased growth rates of Rivulus, which are hypothesized indirect effects of predation. Additional life-history theories show that changes in density and growth can interact with predator-induced mortality to alter the predicted trajectory of evolution. We discuss how these latter frameworks improve the fit between theory and evolution in Rivulus. PMID:21062280

  1. Modeling and experimental verification of thermally induced residual stress in RF-MEMS

    NASA Astrophysics Data System (ADS)

    Somà, Aurelio; Mubasher Saleem, Muhammad

    2015-05-01

    Electrostatically actuated radio frequency microelectromechanical systems (RF-MEMS) generally consist of microcantilevers and clamped-clamped microbeams. The presence of residual stress in these microstructures affects the static and dynamic behavior of the device. In this study, nonlinear finite element method (FEM) modeling and the experimental validation of residual stress induced in the clamped-clamped microbeams and the symmetric toggle RF-MEMS switch (STS) is presented. The formation of residual stress due to plastic deformation during the thermal loading-unloading cycle in the plasma etching step of the microfabrication process is explained and modeled using the Bauschinger effect. The difference between the designed and the measured natural frequency and pull-in voltage values for the clamped-clamped microbeams is explained by the presence of the nonhomogenous tensile residual stress. For the STS switch specimens, three-dimensional (3D) FEM models are developed and the initial deflection at zero bias voltage, observed during the optical profile measurements, is explained by the residual stress developed during the plasma etching step. The simulated residual stress due to the plastic deformation is included in the STS models to obtain the switch pull-in voltage. At the end of the simulation process, a good correspondence is obtained between the FEM model results and the experimental measurements for both the clamped-clamped microbeams and the STS switch specimens.

  2. Experimentally-induced Increases in Early Gesture Lead to Increases in Spoken Vocabulary

    PubMed Central

    LeBarton, Eve Sauer; Goldin-Meadow, Susan; Raudenbush, Stephen

    2014-01-01

    Differences in vocabulary that children bring with them to school can be traced back to the gestures they produce at 1;2, which, in turn, can be traced back to the gestures their parents produce at the same age (Rowe & Goldin-Meadow, 2009b). We ask here whether child gesture can be experimentally increased and, if so, whether the increases lead to increases in spoken vocabulary. Fifteen children aged 1;5 participated in an 8-week at-home intervention study (6 weekly training sessions plus follow-up 2 weeks later) in which all were exposed to object words, but only some were told to point at the named objects. Before each training session and at follow-up, children interacted naturally with caregivers to establish a baseline against which changes in communication were measured. Children who were told to gesture increased the number of gesture meanings they conveyed, not only during training but also during interactions with caregivers. These experimentally-induced increases in gesture led to larger spoken repertoires at follow-up. PMID:26120283

  3. Inability of two topical treatments to influence the course of experimentally induced dermatophytosis in cats.

    PubMed

    DeBoer, D J; Moriello, K A

    1995-07-01

    An experimental model of dermatophytosis was used to compare the efficacy of 2 topical antifungal treatments against Microsporum canis infection in cats. Infection was established in 24 cats by topical application of 10(5) M canis macroconidia to the skin of the lateral part of the abdomen under an occlusive bandage. Three groups of 6 cats each then were treated twice weekly for 18 weeks with chlorhexidine shampoo and dip, detergent shampoo vehicle only, or glyceryl monolaurate shampoo. Six cats were left untreated as controls. The experimentally induced infections strongly resembled naturally developing infections of moderate to severe nature. Signs of infection peaked in severity at 5 weeks after inoculation, then gradually resolved over 7 to 16 additional weeks. Dermatophytes were consistently isolated on culture for at least 8 weeks of treatment. Mycologic cure (defined as lack of dermatophyte isolation on 3 successive weekly cultures) was attained in 8 cats at the end of 18 weeks of treatment. Infections appeared to resolve at equivalent rates in all groups of cats, including controls. Consistent or meaningful significant differences in variables such as lesion size, clinical sign score, or total infection score were not found between treated and control groups. Our study revealed that this topical treatment regimen with chlorhexidine or glyceryl monolaurate is ineffective against M canis infection in cats. PMID:7601693

  4. Innate immune response in experimentally induced bovine intramammary infection with Staphylococcus simulans and S. epidermidis

    PubMed Central

    2011-01-01

    Coagulase-negative staphylococci (CNS) are in several countries the most common bacteria isolated in subclinical mastitis. To investigate the innate immune response of cows to infections with two common mastitis-causing CNS species, Staphylococcus epidermidis and Staphylococcus simulans, experimental intramammary infection was induced in eight cows using a crossover design. The milk somatic cell count (SCC), N-acetyl-β-D-glucosaminidase (NAGase) activity, milk amyloid A (MAA), serum amyloid A (SAA) and proinflammatory cytokines interleukin (IL)-1β, IL-8, and tumor necrosis factor α (TNF-α) were determined at several time points before and after challenge. All cows became infected and showed mild to moderate clinical signs of mastitis. The spontaneous elimination rate of the 16 infections was 31.3%, with no difference between species. Infections triggered a local cytokine response in the experimental udder quarters, but cytokines were not detected in the uninfected control quarters or in systemic circulation. The innate local immune response for S. simulans was slightly stronger, with significantly higher concentrations of IL-1β and IL-8. The IL-8 response could be divided into early, delayed, or combined types of response. The CNS species or persistency of infection was not associated with the type of IL-8 response. No significant differences were seen between spontaneously eliminated or persistent infections. PMID:21414189

  5. Experimental optic neuritis induced by the microinjection of lipopolysaccharide into the optic nerve.

    PubMed

    Aranda, Marcos L; Dorfman, Damián; Sande, Pablo H; Rosenstein, Ruth E

    2015-04-01

    Optic neuritis (ON) is a condition involving primary inflammation, demyelination, and axonal injury in the optic nerve which leads to retinal ganglion cell (RGC) loss, and visual dysfunction. We investigated the ability of a single microinjection of bacterial lipopolysaccharide (LPS) directly into the optic nerve to induce functional and structural alterations compatible with ON. For this purpose, optic nerves from male Wistar rats remained intact or were injected with vehicle or LPS. The effect of LPS was evaluated at several time points post-injection in terms of: i) visual pathway and retinal function (visual evoked potentials (VEPs) and electroretinograms, (ERGs), respectively), ii) anterograde transport from the retina to its projection areas, iii) consensual pupil light reflex (PLR), iv) optic nerve histology, v) microglia/macrophage reactivity (by Iba-1- and ED1-immunostaining), vi) astrocyte reactivity (by glial fibrillary acid protein-immunostaining), vii) axon number (by toluidine blue staining), vii) demyelination (by myelin basic protein immunoreactivity and luxol fast blue staining), viii) optic nerve ultrastructure, and ix) RGC number (by Brn3a immunoreactivity). LPS induced a significant and persistent decrease in VEP amplitude and PLR, without changes in the ERG. In addition, LPS induced a deficit in anterograde transport, and an early inflammatory response consisting in an increased cellularity, and Iba-1 and ED1-immunoreactivity in the optic nerve, which were followed by changes in axonal density, astrocytosis, demyelination, and axon and RGC loss. These results suggest that the microinjection of LPS into the optic nerve may serve as a new experimental model of primary ON. PMID:25687552

  6. Computational and experimental analysis of TMS-induced electric field vectors critical to neuronal activation

    NASA Astrophysics Data System (ADS)

    Krieg, Todd D.; Salinas, Felipe S.; Narayana, Shalini; Fox, Peter T.; Mogul, David J.

    2015-08-01

    Objective. Transcranial magnetic stimulation (TMS) represents a powerful technique to noninvasively modulate cortical neurophysiology in the brain. However, the relationship between the magnetic fields created by TMS coils and neuronal activation in the cortex is still not well-understood, making predictable cortical activation by TMS difficult to achieve. Our goal in this study was to investigate the relationship between induced electric fields and cortical activation measured by blood flow response. Particularly, we sought to discover the E-field characteristics that lead to cortical activation. Approach. Subject-specific finite element models (FEMs) of the head and brain were constructed for each of six subjects using magnetic resonance image scans. Positron emission tomography (PET) measured each subject’s cortical response to image-guided robotically-positioned TMS to the primary motor cortex. FEM models that employed the given coil position, orientation, and stimulus intensity in experimental applications of TMS were used to calculate the electric field (E-field) vectors within a region of interest for each subject. TMS-induced E-fields were analyzed to better understand what vector components led to regional cerebral blood flow (CBF) responses recorded by PET. Main results. This study found that decomposing the E-field into orthogonal vector components based on the cortical surface geometry (and hence, cortical neuron directions) led to significant differences between the regions of cortex that were active and nonactive. Specifically, active regions had significantly higher E-field components in the normal inward direction (i.e., parallel to pyramidal neurons in the dendrite-to-axon orientation) and in the tangential direction (i.e., parallel to interneurons) at high gradient. In contrast, nonactive regions had higher E-field vectors in the outward normal direction suggesting inhibitory responses. Significance. These results provide critical new

  7. Experimental infection with equine herpesvirus type 1 (EHV-1) induces chorioretinal lesions

    PubMed Central

    2013-01-01

    Equine herpesvirus myeloencephalitis (EHM) remains one of the most devastating manifestations of equine herpesvirus type 1 (EHV-1) infection but our understanding of its pathogenesis remains rudimentary, partly because of a lack of adequate experimental models. EHV-1 infection of the ocular vasculature may offer an alternative model as EHV-1-induced chorioretinopathy appears to occur in a significant number of horses, and the pathogenesis of EHM and ocular EHV-1 may be similar. To investigate the potential of ocular EHV-1 as a model for EHM, and to determine the frequency of ocular EHV-1, our goal was to study: (1) Dissemination of virus following acute infection, (2) Development and frequency of ocular lesions following infection, and (3) Utility of a GFP-expressing virus for localization of the virus in vivo. Viral antigen could be detected following acute infection in ocular tissues and the central nervous system (experiment 1). Furthermore, EHV-1 infection resulted in multifocal choroidal lesions in 90% (experiment 2) and 50% (experiment 3) of experimentally infected horses, however ocular lesions did not appear in vivo until between 3 weeks and 3 months post-infection. Taken together, the timing of the appearance of lesions and their ophthalmoscopic features suggest that their pathogenesis may involve ischemic injury to the chorioretina following viremic delivery of virus to the eye, mirroring the vascular events that result in EHM. In summary, we show that the frequency of ocular EHV-1 is 50-90% following experimental infection making this model attractive for testing future vaccines or therapeutics in an immunologically relevant age group. PMID:24308772

  8. Experimental and Numerical Study of Laser-Induced Forward Transfer Printing of Liquids

    NASA Astrophysics Data System (ADS)

    Brown, Matthew S.

    Laser-induced forward transfer (LIFT) is an emerging high-resolution printing technique, which can deposit a wide range of fluid materials without a nozzle. In this process, a pulsed laser initiates the highly directed expulsion of fluid from a thin donor ink film onto a confined region of an acceptor substrate. Despite being validated as a versatile technique for printing devices, the fundamental mechanisms of the deposition process are still not fully understood. Further investigation of the laser-induced ejection dynamics is necessary in order to motivate new ways in which to optimize and control the printing process. Additionally, the LIFT configuration presents a unique laboratory in which to study novel regimes of fluid dynamics. This thesis presents an in-depth study of the LIFT printing process using a balance of experimental measurement and computational modeling. In the first part, time-resolved imaging is used to investigate the mechanisms responsible for the laser-induced ejection of ink. Fluid ejections driven by a rapidly expanding gas cavity within the ink film are observed and analyzed within the context of similar work on cavitation bubble formation, revealing that the unique geometry and size scale of LIFT invokes novel flow behavior. An alternative mechanism is also observed in which the fluid is ejected by the rapid formation of blister on a polymer layer adjacent to the ink film. The dynamics of the blister expansion and associated ink ejection are analyzed as a function of system properties and processing parameters. In the second part, a computational model of the blister-actuated ejection process is developed and used to study the novel regime of free-surface jetting from thin liquid films. The model is first validated against experimental results. It is then used to develop a fundamental understanding of the ejection process as well as conduct a detailed parametric study on the influence of system parameters on printing performance. These

  9. The effect of spinal manipulative therapy on experimentally induced pain: a systematic literature review

    PubMed Central

    2012-01-01

    Background Although there is evidence that spinal manipulative therapy (SMT) can reduce pain, the mechanisms involved are not well established. There is a need to review the scientific literature to establish the evidence-base for the reduction of pain following SMT. Objectives To determine if SMT can reduce experimentally induced pain, and if so, if the effect is i) only at the level of the treated spinal segment, ii) broader but in the same general region as SMT is performed, or iii) systemic. Design A systematic critical literature review. Methods A systematic search was performed for experimental studies on healthy volunteers and people without chronic syndromes, in which the immediate effect of SMT was tested. Articles selected were reviewed blindly by two authors. A summary quality score was calculated to indicate level of manuscript quality. Outcome was considered positive if the pain-reducing effect was statistically significant. Separate evidence tables were constructed with information relevant to each research question. Results were interpreted taking into account their manuscript quality. Results Twenty-two articles were included, describing 43 experiments, primarily on pain produced by pressure (n = 27) or temperature (n = 9). Their quality was generally moderate. A hypoalgesic effect was shown in 19/27 experiments on pressure pain, produced by pressure in 3/9 on pain produced by temperature and in 6/7 tests on pain induced by other measures. Second pain provoked by temperature seems to respond to SMT but not first pain. Most studies revealed a local or regional hypoalgesic effect whereas a systematic effect was unclear. Manipulation of a “restricted motion segment” (“manipulable lesion”) seemed not to be essential to analgesia. In relation to outcome, there was no discernible difference between studies with higher vs. lower quality scores. Conclusions These results indicate that SMT has a direct local/regional hypoalgesic effect on

  10. Electroacupuncture-Induced Attenuation of Experimental Epilepsy: A Comparative Evaluation of Acupoints and Stimulation Parameters

    PubMed Central

    Kang, Xuezhi; Shen, Xueyong; Xia, Ying

    2013-01-01

    The efficacy of electroacupuncture (EA) on epilepsy remains to be verified because of previous controversies that might be due to the complexity of the effects induced by different acupoints and stimulation approaches adopted. Therefore, we investigated the effects of EA on epilepsy to determine the specific acupoints and optimal stimulation parameters in this work. Experimental epilepsy was induced by injecting kainic acid to the lateral cerebral ventricle of adult male SD rats. EA with a low-frequency (10 Hz/1 mA) or high-frequency (100 Hz/1 mA) current was applied to the epileptic model for 30 minutes starting at 0.5 hour after the injection. Four pairs of acupoints were tested, that is, Shuigou (DU26) + Dazhui (DU14), Jinsuo (DU8) + Yaoqi (EXB9), Neiguan (PC6) + Quchi (LI11), and Fenglong (ST40) + Yongquan (KI1). We found that (1) low- or high-frequency EA at different acupoints reduced epileptic seizures (P < 0.05 versus the control) with an exception of low-frequency EA at Neiguan (PC6) and Quchi (LI11); (2) low-frequency EA induced a better effect at Fenglong (ST40) plus Yongquan (KI1) than that of the other acupoints (P < 0.05); (3) there is no significant difference in the effects of high-frequency EA at these acupoints; and (4) the high-frequency EA elicited a greater effect than that of low-frequency EA in all groups (P < 0.05), with an exception at Jinsuo (DU8) + Yaoqi (EXB9). The EA-induced attenuation appeared 1–1.5 hours after EA with no appreciable effect in the first hour after EA in either the EEG or the behavioral tests. We conclude that EA attenuation of epileptic seizures is dependent on the stimulation parameters and acupoints and that the delay in appearance of the EA effect could be a reflection of the time required by the EA signal to regulate neural function in the central nervous system. PMID:23589718

  11. Experimentally induced vitamin E-selenium deficiency in the growing dog.

    PubMed

    Van Vleet, J F

    1975-04-15

    Eight 5-to 8-week-old Beagle pups were allotted to 4 groups of 2 dogs each. For 55 to 70 days, they were fed either a semisynthetic basal diet (BD) deficient in vitamin E and selenium (Se) (group 1) or the BD supplemented with either 30 IU alpha-tocopherol/kg (group 2), 0.5 ppm Se as selenite (group 3), or 1.0 ppm Se as selenite (group 4). In the dogs fed the BD, clinical signs of vitamin E-Se deficiency developed after 40 to 60 days. These signs were accompanied by increased plasma activity of creatine phosphokinase (CPK) and glutamic oxalacetic transaminase (GOT). The dogs were euthanatized after 10 to 15 days of progressive clinical signs, including muscular weakness, subcutaneous edema, anorexia, depression, dyspnea, and eventual coma. Gross lesions seen at necropsy included ventral subcutaneous edema, generalized skeletal muscular pallor and edema with scattered white longitudinal streaking, prominent brownish yellow discoloration of the intestinal musculature, and a layer of white chalky material at the renal corticomedullary junction. Microscopically, there was evidence of extensive skeletal muscular degeneration and regeneration, focal subendocardial necrosis in the ventricular myocardium, intestinal lipofuscinosis, and renal mineralization. Mean hepatic Se content in the dogs fed the BD was 0.10 ppm (wet weight basis) at necropsy. In the dogs fed the 3 supplemented diets, clinical signs of deficiency did not develop. At necropsy, mild skeletal myopathy was evident histologically in the dogs fed BD and 0.5 ppm Se (group 3) but not in the dogs fed the other supplemented diets. Intestinal lipofuscinosis was found in the dogs fed the 3 supplemented diets but was less severe in the dogs fed the diet supplemented with vitamin E than in those fed diets supplemented with Se. PMID:1120735

  12. Systematic experimental study on a highly efficient terahertz source based on two-color laser-induced air plasma

    NASA Astrophysics Data System (ADS)

    Xie, Jun; Fan, Wen-Hui; Chen, Xu

    2016-05-01

    In this paper, highly efficient terahertz radiation generated by two-color femtosecond laser-induced air plasma is reported. A number of variables that can obviously influence terahertz generation and detection have been investigated systematically. The dependence on experimental parameters, including pulse energy, the rotation angle of beta-barium boron oxide (BBO) crystal, the distance between BBO crystal and laser-induced plasma, focal length, chopper frequency, and detection angle are presented, and the optimal values of these parameters have also been obtained experimentally. Finally, a highly efficient terahertz source has been achieved and can be utilized to carry out further investigation on terahertz sensing, spectroscopy, and imaging.

  13. Experimental and predicted cavitation performance of an 80.6 deg helical inducer in high temperature water

    NASA Technical Reports Server (NTRS)

    Kovich, G.

    1972-01-01

    The cavitating performance of a stainless steel 80.6 degree flat-plate helical inducer was investigated in water over a range of liquid temperatures and flow coefficients. A semi-empirical prediction method was used to compare predicted values of required net positive suction head in water with experimental values obtained in water. Good agreement was obtained between predicted and experimental data in water. The required net positive suction head in water decreased with increasing temperature and increased with flow coefficient, similar to that observed for a like inducer in liquid hydrogen.

  14. Expectation-induced placebo responses fail to accelerate wound healing in healthy volunteers: results from a prospective controlled experimental trial.

    PubMed

    Vits, Sabine; Dissemond, Joachim; Schadendorf, Dirk; Kriegler, Lisa; Körber, Andreas; Schedlowski, Manfred; Cesko, Elvir

    2015-12-01

    Placebo responses have been shown to affect the symptomatology of skin diseases. However, expectation-induced placebo effects on wound healing processes have not been investigated yet. We analysed whether subjects' expectation of receiving an active drug accelerates the healing process of experimentally induced wounds. In 22 healthy men (experimental group, n = 11; control group, n = 11) wounds were induced by ablative laser on both thighs. Using a deceptive paradigm, participants in the experimental group were informed that an innovative 'wound gel' was applied on one of the two wounds, whereas a 'non-active gel' was applied on the wound of the other thigh. In fact, both gels were identical hydrogels without any active components. A control group was informed to receive a non-active gel on both wounds. Progress in wound healing was documented via planimetry on days 1, 4 and 7 after wound induction. From day 9 onwards wound inspections were performed daily accompanied by a change of the dressing and a new application of the gel. No significant differences could be observed with regard to duration or process of wound healing, either by intraindividual or by interindividual comparisons. These data document no expectation-induced placebo effect on the healing process of experimentally induced wounds in healthy volunteers. PMID:24373522

  15. Chronic cough and dyspnea in ice hockey players after an acute exposure to combustion products of a faulty ice resurfacer.

    PubMed

    Kahan, Erika S; Martin, Ubaldo J; Spungen, Steve; Ciccolella, David; Criner, Gerard J

    2007-01-01

    The aim of this study was to characterize pulmonary function and radiologic testing in ice hockey players after exposure to combustion products of a faulty ice resurfacer. Our patients were 16 previously healthy hockey players who developed chronic cough and dyspnea after exposure. Symptom questionnaires, pulmonary function tests (PFTs), bronchoprovocation testing, cardiopulmonary exercise testing, high-resolution computed tomography (CT) imaging, and impulse oscillometry (IOS) were all used. A normal group was used for PFTs and IOS controls. Patients had onset of cough within 72 h of exposure. Ninety-two percent complained of dyspnea, 75% chest pain, and 33% hemoptysis. Eight percent were initially hospitalized for their symptoms. Eighty-five percent were treated with systemic steroids and 39% with inhaled bronchodilators. Six months postexposure, 54% complained of cough and 46% complained of dyspnea on exertion. All patients had normal PFTs; 8.3% had a significant bronchodilator response. All had normal exercise tests (mean VO2max = 90 +/- 3% predicted) and chest CTs. With IOS, 80% had a significant bronchodilator response (decreased resistance > 12% and SD score > 1; mean change = 21.1 +/- 9.9%, mean SD score = 3.1 +/- 2.5). No correlation existed between changes in resistance or reactance and spirometric values. Patient symptoms correlated significantly with bronchodilator response on IOS resistance (R=0.61, p=0.03). More than 50% of patients exposed to the combustion products of a faulty ice resurfacer remained symptomatic six months after exposure. Despite persistence of symptoms, conventional pulmonary function tests and radiologic evaluation did not reveal airway abnormalities. IOS showed evidence of increased airway resistance and small-airway disease, which correlated with patient symptoms. PMID:17294334

  16. Schistosoma mansoni Tegument (Smteg) Induces IL-10 and Modulates Experimental Airway Inflammation

    PubMed Central

    2016-01-01

    Background Previous studies have demonstrated that S. mansoni infection and inoculation of the parasite eggs and antigens are able to modulate airways inflammation induced by OVA in mice. This modulation was associated to an enhanced production of interleukin-10 and to an increased number of regulatory T cells. The S. mansoni schistosomulum is the first stage to come into contact with the host immune system and its tegument represents the host-parasite interface. The schistosomula tegument (Smteg) has never been studied in the context of modulation of inflammatory disorders, although immune evasion mechanisms take place in this phase of infection to guarantee the persistence of the parasite in the host. Methodology and Principal Findings The aim of this study was to evaluate the Smteg ability to modulate inflammation in an experimental airway inflammation model induced by OVA and to characterize the immune factors involved in this modulation. To achieve the objective, BALB/c mice were sensitized with ovalbumin (OVA) and then challenged with OVA aerosol after Smteg intraperitoneal inoculation. Protein extravasation and inflammatory cells were assessed in bronchoalveolar lavage and IgE levels were measured in serum. Additionally, lungs were excised for histopathological analyses, cytokine measurement and characterization of the cell populations. Inoculation with Smteg led to a reduction in the protein levels in bronchoalveolar lavage (BAL) and eosinophils in both BAL and lung tissue. In the lung tissue there was a reduction in inflammatory cells and collagen deposition as well as in IL-5, IL-13, IL-25 and CCL11 levels. Additionally, a decrease in specific anti-OVA IgE levels was observed. The reduction observed in these inflammatory parameters was associated with increased levels of IL-10 in lung tissues. Furthermore, Smteg/asthma mice showed high percentage of CD11b+F4/80+IL-10+ and CD11c+CD11b+IL-10+ cells in lungs. Conclusion Taken together, these findings

  17. A new experimental model of acid- and endotoxin-induced acute lung injury in rats.

    PubMed

    Puig, F; Herrero, R; Guillamat-Prats, R; Gómez, M N; Tijero, J; Chimenti, L; Stelmakh, O; Blanch, L; Serrano-Mollar, A; Matthay, M A; Artigas, A

    2016-08-01

    The majority of the animal models of acute lung injury (ALI) are focused on the acute phase. This limits the studies of the mechanisms involved in later phases and the effects of long-term treatments. Thus the goal of this study was to develop an experimental ALI model of aspiration pneumonia, in which diffuse alveolar damage continues for 72 h. Rats were intratracheally instilled with one dose of HCl (0.1 mol/l) followed by another instillation of one dose of LPS (0, 10, 20, 30, or 40 μg/g body weight) 2 h later, which models aspiration of gastric contents that progresses to secondary lung injury from bacteria or bacterial products. The rats were euthanized at 24, 48, and 72 h after the last instillation. The results showed that HCl and LPS at all doses caused activation of inflammatory responses, increased protein permeability and apoptosis, and induced mild hypoxemia in rat lungs at 24 h postinstillation. However, this lung damage was present at 72 h only in rats receiving HCl and LPS at the doses of 30 and 40 μg/g body wt. Mortality (∼50%) occurred in the first 48 h and only in the rats treated with HCl and LPS at the highest dose (40 μg/g body wt). In conclusion, intratracheal instillation of HCl followed by LPS at the dose of 30 μg/g body wt results in severe diffuse alveolar damage that continues at least 72 h. This rat model of aspiration pneumonia-induced ALI will be useful for testing long-term effects of new therapeutic strategies in ALI. PMID:27317688

  18. Anti-Thymocyte Globulin Induces Neoangiogenesis and Preserves Cardiac Function after Experimental Myocardial Infarction

    PubMed Central

    Lichtenauer, Michael; Mildner, Michael; Werba, Gregor; Beer, Lucian; Hoetzenecker, Konrad; Baumgartner, Andrea; Hasun, Matthias; Nickl, Stefanie; Mitterbauer, Andreas; Zimmermann, Matthias; Gyöngyösi, Mariann; Podesser, Bruno Karl; Klepetko, Walter; Ankersmit, Hendrik Jan

    2012-01-01

    Rationale Acute myocardial infarction (AMI) followed by ventricular remodeling is the major cause of congestive heart failure and death in western world countries. Objective Of relevance are reports showing that infusion of apoptotic leucocytes or anti-lymphocyte serum after AMI reduces myocardial necrosis and preserves cardiac function. In order to corroborate this therapeutic mechanism, the utilization of an immunosuppressive agent with a comparable mechanism, such as anti-thymocyte globulin (ATG) was evaluated in this study. Methods and Results AMI was induced in rats by ligation of the left anterior descending artery. Initially after the onset of ischemia, rabbit ATG (10 mg/rat) was injected intravenously. In vitro and in vivo experiments showed that ATG induced a pronounced release of pro-angiogenic and chemotactic factors. Moreover, paracrine factors released from ATG co-incubated cell cultures conferred a down-regulation of p53 in cardiac myocytes. Rats that were injected with ATG evidenced higher numbers of CD68+ macrophages in the ischemic myocardium. Animals injected with ATG evidenced less myocardial necrosis, showed a significant reduction of infarct dimension and an improvement of post-AMI remodeling after six weeks (infarct dimension 24.9% vs. 11.4%, p<0.01). Moreover, a higher vessel density in the peri-infarct region indicated a better collateralization in rats that were injected with ATG. Conclusions These data indicate that ATG, a therapeutic agent successfully applied in clinical transplant immunology, triggered cardioprotective effects after AMI that salvaged ischemic myocardium by down-regulation of p53. This might have raised the resistance against apoptotic cell death during ischemia. The combination of these mechanisms seems to be causative for improved cardiac function and less ventricular remodeling after experimental AMI. PMID:23284885

  19. Electromagnetically induced absorption in detuned stub waveguides: a simple analytical and experimental model.

    PubMed

    Mouadili, A; Boudouti, E H El; Soltani, A; Talbi, A; Djafari-Rouhani, B; Akjouj, A; Haddadi, K

    2014-12-17

    We give an analytical and experimental demonstration of a classical analogue of the electromagnetic induced absorption (EIA) in a simple photonic device consisting of two stubs of lengths d1 and d2 grafted at the same site along a waveguide. By detuning the lengths of the two stubs (i.e. δ = d(2) - d(1)) we show that: (i) the amplitudes of the electromagnetic waves in the two stubs can be written following the two resonators model where each stub plays the role of a radiative resonator with low Q factor. The destructive interference between the waves in the two stubs may give rise to a sharp resonance peak with high Q factor in the transmission as well as in the absorption. (ii) The transmission coefficient around the resonance induced by the stubs can be written following a Fano-like form. In particular, we give an explicit expression of the position, width and Fano parameter of the resonances as a function of δ. (iii) By taking into account the loss in the waveguides, we show that at the transmission resonance, the transmission (reflection) increases (decreases) as a function of δ. Whereas the absorption goes through a maximum around 0.5 for a threshold value δth which depends on the attenuation in the system and then falls to zero. (iv) We give a comparison between the phase of the determinant of the scattering matrix, the so-called Friedel phase and the phase of the transmission amplitude. (v) The effect of the boundary conditions at the end of the resonators on the EIA resonance is also discussed. The analytical results are obtained by means of the Green's function method, whereas the experiments are carried out using coaxial cables in the radio-frequency regime. These results should have important consequences for designing integrated devices such as narrow-frequency optical or microwave filters and high-speed switches. PMID:25406973

  20. Intrinsic and induced regulation of the age-associated onset of spontaneous experimental autoimmune encephalomyelitis.

    PubMed

    Zhang, Hong; Podojil, Joseph R; Luo, Xunrong; Miller, Stephen D

    2008-10-01

    Multiple sclerosis is characterized by perivascular CNS infiltration of myelin-specific CD4(+) T cells and activated mononuclear cells. TCR transgenic mice on the SJL background specific for proteolipid protein (PLP)(139-151) develop a high incidence of spontaneous experimental autoimmune encephalomyelitis (sEAE). We examined the intrinsic mechanisms regulating onset and severity of sEAE. CD4(+) T cells isolated from the cervical lymph nodes, but not spleens, of diseased 5B6 transgenic mice are hyperactivated when compared with age-matched healthy mice and produce both IFN-gamma and IL-17, indicating that the cervical lymph node is the initial peripheral activation site. The age-associated development of sEAE correlates with a decline in both the functional capacity of natural regulatory T cells (nTregs) and in PLP(139-151)-induced IL-10 production and a concomitant increase in IL-17 production. Anti-CD25-induced inactivation of nTregs increased the incidence and severity of sEAE. Conversely, induction of peripheral tolerance via the i.v. injection of PLP(139-151)-pulsed, ethylcarbodiimide-fixed APCs (PLP(139-151)-SP) inhibited the development of clinical disease concomitant with increased production of IL-10 and conversion of Foxp3(+) Tregs from CD4(+)CD25(-) progenitors. These data indicate that heterogeneous populations of Tregs regulate onset of sEAE, and that induction of peripheral tolerance can be exploited to prevent/treat spontaneous autoimmune disease. PMID:18802066

  1. Human mesenchymal stem cells attenuate experimental bronchopulmonary dysplasia induced by perinatal inflammation and hyperoxia

    PubMed Central

    Chou, Hsiu-Chu; Li, Yuan-Tsung; Chen, Chung-Ming

    2016-01-01

    Background: Systemic maternal inflammation and neonatal hyperoxia arrest alveolarization in neonates. The aims were to test whether human mesenchymal stem cells (MSCs) reduce lung inflammation and improve lung development in perinatal inflammation- and hyperoxia-induced experimental bronchopulmonary dysplasia. Methods: Pregnant Sprague-Dawley rats were intraperitoneally injected with lipopolysaccharide (LPS, 0.5 mg/kg/day) on Gestational Days 20 and 21. Human MSCs (3×105 and 1×106 cells) in 0.03 ml normal saline (NS) were administered intratracheally on Postnatal Day 5. Pups were reared in room air (RA) or an oxygen-enriched atmosphere (O2) from Postnatal Days 1 to 14, and six study groups were obtained: LPS+RA+NS, LPS+RA+MSC (3×105 cells), LPS+RA+MSC (1×106 cells), LPS+O2+NS, LPS+O2+MSC (3×105 cells), and LPS+O2+MSC (1×106 cells). The lungs were excised for cytokine, vascular endothelial growth factor (VEGF) and connective tissue growth factor (CTGF) expression, and histological analyses on Postnatal Day 14. Results: Body weight was significantly lower in rats reared in hyperoxia than in those reared in RA. The LPS+O2+NS group exhibited a significantly higher mean linear intercept (MLI) and collagen density and a significantly lower vascular density than the LPS+RA+NS group did. Administering MSC to hyperoxia-exposed rats improved MLI and vascular density and reduced tumor necrosis factor-α and interleukin-6 levels and collagen density to normoxic levels. This improvement in lung development and fibrosis was accompanied by an increase and decrease in lung VEGF and CTGF expression, respectively. Conclusion: Human MSCs attenuated perinatal inflammation- and hyperoxia-induced defective alveolarization and angiogenesis and reduced lung fibrosis, likely through increased VEGF and decreased CTGF expression. PMID:27158330

  2. Chemopreventive effect of sinapic acid on 1,2-dimethylhydrazine-induced experimental rat colon carcinogenesis.

    PubMed

    Balaji, C; Muthukumaran, J; Nalini, N

    2014-12-01

    Sinapic acid (SA) is a naturally occurring phenolic acid found in various herbal plants which is attributed with numerous pharmacological properties. This study was aimed to investigate the chemopreventive effect of SA on 1,2-dimethylhydrazine (DMH)-induced rat colon carcinogenesis. Rats were treated with DMH injections (20 mg kg(-1) bodyweight (b.w.) subcutaneously once a week for the first 4 consecutive weeks and SA (20, 40 and 80 mg kg(-1) b.w.) post orally for 16 weeks. At the end of the 16-week experimental period, all the rats were killed, and the tissues were evaluated biochemically. Our results reveal that DMH alone treatment decreased the levels/activities of lipid peroxidation by-products such as thiobarbituric acid reactive substances, conjugated dienes and antioxidants such as superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and reduced glutathione in the intestine and colonic tissues which were reversed on supplementation with SA. Moreover, the activities of drug-metabolizing enzymes of phase I (cytochrome P450 and P4502E1) were enhanced and those of phase II (glutathione-S-transferase, DT-diaphorase and uridine diphosphate glucuronosyl transferase) were diminished in the liver and colonic mucosa of DMH alone-treated rats and were reversed on supplementation with SA. All the above changes were supported by the histopathological observations of the rat liver and colon. These findings suggest that SA at the dose of 40 mg kg(-1) b.w. was the most effective dose against DMH-induced colon carcinogenesis, and thus, SA could be used as a potential chemopreventive agent. PMID:24532707

  3. Effect of a lipid-rich emollient containing ceramide 3 in experimentally induced skin barrier dysfunction.

    PubMed

    Kucharekova, M; Schalkwijk, J; Van De Kerkhof, P C M; Van De Valk, P G M

    2002-06-01

    In the present study we compared the effect of a ceramide 3-containing emollient (Locobase(R) Repair) with a control emollient (vaselinum album/cremor lanette ana) and untreated damaged skin using clinical, bioengineering and immunohistochemical methods in two different models of experimentally induced skin barrier dysfunction. In model A (n = 13) skin barrier dysfunction was inflicted at three investigation sites by tape stripping. In model B (n = 13) the volunteers were patch tested at three investigation sites with sodium dodecyl sulphate (0.2%) for 4 h a day for 4 consecutive days. The investigation sites were treated once a day with the above-mentioned agents. Irritant reaction was assessed daily by erythema scoring and measurements of transepidermal water loss (TEWL). After 5D, punch biopsies were taken from all sites. Immunohistochemical assessment was carried out with respect to epidermal proliferation, epidermal differentiation and Langerhans cells. Tape stripping resulted in an erythematous reaction and an increase of TEWL associated with up-regulation of cycling cells, involucrin and expression of cytokeratin 16. At day 4, ceramide 3-containing emollient significantly decreased (p < 0.03) the erythema score, TEWL and cycling cells in comparison with the untreated site. Repetitive exposure to SDS induced a variable degree of erythema, gradual increase of TEWL, an increase of cycling cells, and up-regulation of involucrin, E-FABP and SKALP. The treatment with the control emollient significantly prevented erythema, increase of TEWL and cycling cells at day 4 compared to the untreated site. In summary, the present study demonstrated that both tested emollients improve skin barrier in different conditions compared to the untreated skin. There is some indication that formulations containing skin-related lipids might be of benefit in barrier disruption following tape stripping. Different models and clinical trials are needed to establish the usefulness in

  4. Amelioration of Cisplatin-Induced Experimental Peripheral Neuropathy by a Small Molecule Targeting p75NTR

    PubMed Central

    Friesland, Amy; Weng, Zhiying; Duenas, Maria; Massa, Stephen M.; Longo, Frank M.; Lu, Qun

    2014-01-01

    Cisplatin is an effective and widely used first-line chemotherapeutic drug for treating cancers. However, many patients sustain cisplatin-induced peripheral neuropathy (CIPN), often leading to a reduction in drug dosages or complete cessation of treatment altogether. Therefore, it is important to understand cisplatin mechanisms in peripheral nerve tissue mediating its toxicity and identify signaling pathways for potential intervention. Rho GTPase activation is increased following trauma in several models of neuronal injury. Thus, we investigated whether components of the Rho signaling pathway represent important neuroprotective targets with the potential to ameliorate CIPN and thereby optimize current chemotherapy treatment regimens. We have developed a novel CIPN model in the mouse. Using this model and primary neuronal culture, we determined whether LM11A-31, a small-molecule, orally bioavailable ligand of the p75 neurotrophin receptor (p75NTR), can modulate Rho GTPase signaling and reduce CIPN. Von Frey filament analysis of sural nerve function showed that LM11A-31 treatment prevented decreases in peripheral nerve sensation seen with cisplatin treatment. Morphometric analysis of harvested sural nerves revealed that cisplatin-induced abnormal nerve fiber morphology and the decreases in fiber area were alleviated with concurrent LM11A-31 treatment. Cisplatin treatment increased RhoA activity accompanied by the reduced tyrosine phosphorylation of SHP-2, which was reversed by LM11A-31. LM11A-31 also countered the effects of calpeptin, which activated RhoA by inhibiting SHP-2 tyrosine phosphatase. Therefore, suppression of RhoA signaling by LM11A-31 that blocks proNGF binding to p75NTR or activates SHP-2 tyrosine phosphatase downstream of NGF receptor enhances neuroprotection in experimental CIPN in mouse model. PMID:25277379

  5. Tracking anti-fibrotic pathways of nilotinib and imatinib in experimentally induced liver fibrosis: an insight.

    PubMed

    Shiha, Gamal E; Abu-Elsaad, Nashwa M; Zalata, Khaled R; Ibrahim, Tarek M

    2014-10-01

    The tyrosine kinase inhibitors imatinib and nilotinib have been suggested to have promising antifibrotic activity in experimental models of liver fibrosis. The aim of the present study was to investigate new pathways underlying this beneficial effect. Hepatic injury was induced in male Wistar rats by intraperitoneal injection of CCl4 for 12 weeks. During the last 8 weeks of treatment, rats were also injected daily intraperitoneally with 20 mg/kg imatinib or 20, 10 or 5 mg/kg nilotinib. At the end of treatment, effects on fibrosis were assessed by measuring serum fibrotic markers and profibrogenic cytokines, as well as by histopathological examination. Possible anti-inflammatory effects were estimated by measuring levels of inflammatory cytokines in liver tissue. Liver expression of α-smooth muscle actin, transforming growth factor (TGF)-β1 antibodies and platelet-derived growth factor receptor β (PDGFRβ) was evaluated by immunohistochemical staining techniques. Nilotinib (5 and 10 mg/kg) significantly (P < 0.05) decreased all serum fibrotic markers measured, but 20 mg/kg of either nilotinib or imatinib had limited effects. At all doses tested, nilotinib significantly (P < 0.05) decreased the CCl4 -induced increases in tissue inflammatory cytokines. Furthermore, 5 and 10 mg/kg nilotinib significantly decreased TGF-β1 levels and tissue expression of its antibody, as well expression of PDGFRβ. In conclusion, low doses (5 and 10 but not 20 mg/kg) of nilotinib, rather than imatinib, can control hepatic fibrosis by regulating levels of proinflammatory cytokines, primarily interleukin (IL)-1 and IL-6. Nilotinib also controls the signalling pathways of profibrogenic cytokines by lowering TGF-β1 levels and decreasing expression of PDGFRβ. PMID:25115651

  6. Gastroprotective Efficacy and Safety Evaluation of Scoparone Derivatives on Experimentally Induced Gastric Lesions in Rodents

    PubMed Central

    Son, Dong Ju; Lee, Gyung Rak; Oh, Sungil; Lee, Sung Eun; Choi, Won Sik

    2015-01-01

    This study investigated the gastroprotective efficacy of synthesized scoparone derivatives on experimentally induced gastritis and their toxicological safety. Six scoparone derivatives were synthesized and screened for gastroprotective activities against HCl/ethanol- and indomethacin-induced gastric ulcers in rats. Among these compounds, 5,6,7-trimethoxycoumarin and 6,7,8-trimethoxycoumarin were found to have gastroprotective activity greater than the standard drug rebamipide; 6-methoxy-7,8-methylenedioxycoumarin, 6-methoxy-7,8-(1-methoxy)-methylenedioxycoumarin, 6,7-methylenedioxycoumarin, and 6,7-(1-methoxy)-methylenedioxycoumarin were found to be equipotent or less potent that of rebamipide. Pharmacological studies suggest that the presence of a methoxy group at position C-5 or C-8 of the scoparone’s phenyl ring significantly improves gastroprotective activity, whereas the presence of a dioxolane ring at C-6, C-7, or C-8 was found to have decreased activity. In order to assess toxicological safety, two of the potent gastroprotective scoparone derivatives—5,6,7-trimethoxycoumarin and 6,7,8-trimethoxycoumarin—were examined for their acute toxicity in mice as well as their effect on cytochrome P450 (CYP) enzyme activity. These two compounds showed low acute oral toxicity in adult male and female mice, and caused minimal changes to CYP3A4 and CYP2C9 enzyme activity. These results indicate that compared to other scoparone derivatives, 5,6,7-trimethoxycoumarin and 6,7,8-trimethoxycoumarin can improve gastroprotective effects, and they have low toxicity and minimal effects on drug-metabolizing enzymes. PMID:25781220

  7. Cellular Mechanisms and Behavioral Outcomes in Blast-Induced Neurotrauma: Comparing Experimental Setups.

    PubMed

    Bailey, Zachary S; Hubbard, W Brad; VandeVord, Pamela J

    2016-01-01

    Blast-induced neurotrauma (BINT) has increased in incidence over the past decades and can result in cognitive issues that have debilitating consequences. The exact primary and secondary mechanisms of injury have not been elucidated and appearance of cellular injury can vary based on many factors, such as blast overpressure magnitude and duration. Many methodologies to study blast neurotrauma have been employed, ranging from open-field explosives to experimental shock tubes for producing free-field blast waves. While there are benefits to the various methods, certain specifications need to be accounted for in order to properly examine BINT. Primary cell injury mechanisms, occurring as a direct result of the blast wave, have been identified in several studies and include cerebral vascular damage, blood-brain barrier disruption, axonal injury, and cytoskeletal damage. Secondary cell injury mechanisms, triggered subsequent to the initial insult, result in the activation of several molecular cascades and can include, but are not limited to, neuroinflammation and oxidative stress. The collective result of these secondary injuries can lead to functional deficits. Behavioral measures examining motor function, anxiety traits, and cognition/memory problems have been utilized to determine the level of injury severity. While cellular injury mechanisms have been identified following blast exposure, the various experimental models present both concurrent and conflicting results. Furthermore, the temporal response and progression of pathology after blast exposure have yet to be detailed and remain unclear due to limited resemblance of methodologies. This chapter summarizes the current state of blast neuropathology and emphasizes the need for a standardized preclinical model of blast neurotrauma. PMID:27604716

  8. System dynamic instabilities induced by sliding contact: A numerical analysis with experimental validation

    NASA Astrophysics Data System (ADS)

    Brunetti, J.; Massi, F.; Saulot, A.; Renouf, M.; D`Ambrogio, W.

    2015-06-01

    Mechanical systems present several contact surfaces between deformable bodies. The contact interface can be either static (joints) or in sliding (active interfaces). The sliding interfaces can have several roles and according to their application they can be developed either for maximizing the friction coefficient and the energy dissipation (e.g. brakes) or rather to allow the relative displacement at joints with a maximum efficiency. In both cases the coupling between system and local contact dynamics can bring to system dynamics instabilities (e.g. brake squeal or squeaking of hip prostheses). This results in unstable vibrations of the system, induced by the oscillation of the contact forces. In the literature, a large number of works deal with such kind of instabilities and are mainly focused on applied problems such as brake squeal noise. This paper shows a more general numerical analysis of a simple system constituted by two bodies in sliding contact: a rigid cylinder rotating inside a deformable one. The parametrical Complex Eigenvalue Analysis and the transient numerical simulations show how the friction forces can give rise to in-plane dynamic instabilities due to the interaction between two system modes, even for such a simple system characterized by one deformable body. Results from transient simulations highlight the key role of realistic values of the material damping to have convergence of the model and, consequently, reliable physical results. To this aim an experimental estimation of the material damping has been carried out. Moreover, the simplicity of the system allows for a deeper analysis of the contact instability and a balance of the energy flux among friction, system vibrations and damping. The numerical results have been validated by comparison with experimental ones, obtained by a specific test bench developed to reproduce and analyze the contact friction instabilities.

  9. Parameters Optimization of Laser-Induced Breakdown Spectroscopy Experimental Setup for the Case with Beam Expander

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Zhang, Lei; Fan, Juanjuan; Li, Yufang; Gong, Yao; Dong, Lei; Ma, Weiguang; Yin, Wangbao; Jia, Suotang

    2015-11-01

    Improvement of measurement precision and repeatability is one of the issues currently faced by the laser-induced breakdown spectroscopy (LIBS) technique, which is expected to be capable of precise and accurate quantitative analysis. It was found that there was great potential to improve the signal quality and repeatability by reducing the laser beam divergence angle using a suitable beam expander (BE). In the present work, the influences of several experimental parameters for the case with BE are studied in order to optimize the analytical performances: the signal to noise ratio (SNR) and the relative standard deviation (RSD). We demonstrate that by selecting the optimal experimental parameters, the BE-included LIBS setup can give higher SNR and lower RSD values of the line intensity normalized by the whole spectrum area. For validation purposes, support vector machine (SVM) regression combined with principal component analysis (PCA) was used to establish a calibration model to realize the quantitative analysis of the ash content. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The measurement accuracy presented here for ash content analysis is estimated to be 0.31%, while the average relative error is 2.36%. supported by the 973 Program of China (No. 2012CB921603), National Natural Science Foundation of China (Nos. 61475093, 61127017, 61178009, 61108030, 61378047, 61275213, 61475093, and 61205216), the National Key Technology R&D Program of China (No. 2013BAC14B01), the Shanxi Natural Science Foundation (Nos. 2013021004-1 and 2012021022-1), the Shanxi Scholarship Council of China (Nos. 2013-011 and 2013-01), and the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi, China

  10. Effect of pioglitazone, quercetin and hydroxy citric acid on extracellular matrix components in experimentally induced non-alcoholic steatohepatitis

    PubMed Central

    Mohan, Surapaneni Krishna; Veeraraghavan, Vishnu Priya; Jainu, Mallika

    2015-01-01

    Objective(s): Non-alcoholic steatohepatitis (NASH), is an important component of Non-alcoholic fatty liver disease (NAFLD) spectrum, which progresses to the end stage liver disease, if not diagnosed and treated properly. The disproportionate production of pro- and anti-inflammatory adipokines secreted from fat contributes to the pathogenesis of NASH. In this study, the comparative effect of pioglitazone, quercetin and hydroxy citric acid on extracellular matrix (ECM) component levels were studied in experimentally induced NASH. Materials and Methods: The experimental protocol consists of using 48 male Wister rats, which were divided into 8 groups. The levels of hyaluronic acid, leptin and adiponectin were monitored in experimental NASH. Results: The experimental NASH rats treated with pioglitazone showed significant decrease in the levels of hyaluronic acid and significant increase in adiponectin levels when compared to experimentally induced NASH group, but did not show any effect on the levels of leptin. Contrary to these two drugs, viz. pioglitazone and hydroxy citric acid, the group treated with quercetin showed significant decrease in the levels of hyaluronic acid and leptin and significant decrease in adiponectin levels compared with that of experimentally induced NASH NASH group, offering maximum protection against NASH. Conclusion: Considering our findings, it could be concluded that quercetin may offer maximum protection against NASH by significantly increasing the levels of adiponectin, when compared to pioglitazone and hydroxy citric acid. PMID:26557974

  11. Six-Minute Walk Test in Renal Failure Patients: Representative Results, Performance Analysis and Perceived Dyspnea Predictors

    PubMed Central

    Bučar Pajek, Maja; Čuk, Ivan; Leskošek, Bojan; Mlinšek, Gregor; Buturović Ponikvar, Jadranka; Pajek, Jernej

    2016-01-01

    Objectives Six-minute walk test in dialysis population hasn’t been consistently evaluated for the isolated impact of renal failure and other predictive factors. We measured six-minute walk distance in patients representative for low level of comorbidity and searched for potentially modifiable predictive factors of performance and dyspnea. Methods This was a cross-sectional study with hemodialysis patients (N = 90) and control subjects (N = 140). Main outcome measures: six-minute walk test distance and dyspnea severity using the 10-item Borg scale. Results Median distance decreased from 600m below the 6th decade to 420m in the 8th decade of age. Dialysis dependence predicted 101.5m shorter distance in the adjusted model that explained 70% of variability in results. Adjusted for significant covariates of age, height and spontaneous gait speed, fat mass (but not lean body mass) and serum total iron binding capacity were significantly associated with distance (95% CI for B coefficients -4.6 to –1.4 m/kg and 0.1 to 5 m/μmol/l, respectively). Serum total iron binding capacity as an explanatory variable was superior to C-reactive protein and albumin. Dialysis dependence, odds ratio (OR) 2.97 (1.11–7.94), spontaneous gait speed, OR 0.08 (0.02–0.41), rate-pressure product, OR 1.15 (1.08–1.23) and hemoglobin, OR 0.95 (0.92–0.98) predicted dyspnea in the adjusted model. Conclusions Renal failure without the confounding effect of comorbidity is a significant negative predictor of performance at six-minute walk test and perceived level of dyspnea. Body fat mass and serum total iron binding capacity are the main potentially modifiable predictors of performance, total iron binding capacity being superior to C-reactive protein and albumin. Although hemoglobin is not associated with test performance, it negatively predicts perceived shortness of breath. PMID:26982967

  12. Experimental study on impact-induced seismic wave propagating through quartz sand simulating asteroid regolith

    NASA Astrophysics Data System (ADS)

    Matsue, Kazuma; Arakawa, Masahiko; Yasui, Minami; Matsumoto, Rie; Tsujido, Sayaka; Takano, Shota; Hasegawa, Sunao

    2015-08-01

    Introduction: Recent spacecraft surveys clarified that asteroid surfaces were covered with regolith made of boulders and pebbles such as that found on the asteroid Itokawa. It was also found that surface morphologies of asteroids formed on the regolith layer were modified. For example, the high-resolution images of the asteroid Eros revealed the evidence of the downslope movement of the regolith layer, then it could cause the degradation and the erasure of small impact crater. One possible process to explain these observations is the regolith layer collapse caused by seismic vibration after projectile impacts. The impact-induced seismic wave might be an important physical process affecting the morphology change of regolith layer on asteroid surfaces. Therefore, it is significant for us to know the relationship between the impact energy and the impact-induced seismic wave. So in this study, we carried out impact cratering experiments in order to observe the seismic wave propagating through the target far from the impact crater.Experimental method: Impact cratering experiments were conducted by using a single stage vertical gas gun set at Kobe Univ and a two-stage vertical gas gun set at ISAS. We used quartz sands with the particle diameter of 500μm, and the bulk density of 1.48g/cm3. The projectile was a ball made of polycarbonate with the diameter of 4.75mm and aluminum, titan, zirconia, stainless steel, cupper, tungsten carbide projectile with the diameter of 2mm. These projectiles were launched at the impact velocity from 0.2 to 7km/s. The target was set in a vacuum chamber evacuated below 10 Pa. We measured the seismic wave by using a piezoelectric uniaxial accelerometer.Result: The impact-induced seismic wave was measured to show a large single peak and found to attenuate with the propagation distance. The maximum acceleration of the seismic wave was recognized to have a good relationship with the normalized distance x/R, where x is the propagation distance

  13. Investigation of the indulgence cycles hypothesis of suppression on experimentally induced visual intrusions in dysphoria.

    PubMed

    Williams, Alishia D; Moulds, Michelle L

    2007-11-01

    Within the thought control literature, Wegner [(1989). White bears and other unwanted thoughts: Suppression, obsession, and the psychology of mental control. New York, NY, USA: Penguin Press.] referred to the combined initial suppression and expression phases of thought control as an indulgence cycle which results in the rebound effect typically observed in suppression studies. According to Ironic Process Theory [Wegner, (1994). Ironic processes of mental control. Psychological Review, 101, 34-52.], this rebound leads to further attempts to suppress that are difficult due to the target thought's hyperaccessibility, resulting in a secondary rebound effect owing to a positive feedback system of indulgence cycles. The current study investigated (i) the effects of repeated suppression and opportunities for expression by using a method to index the frequency, duration, and associated levels of distress of an experimentally induced visual intrusion, and (ii) whether any observed effects were differentially linked to depressive symptomatology in an analogue sample of low and high dysphoric participants. Results supported a secondary rebound effect in those participants most successful at suppressing target intrusions. The findings offer an important extension to the emerging literature on the management of intrusive memories in depression. PMID:17692285

  14. Experimental study on the onset of cavitation induced by an impact

    NASA Astrophysics Data System (ADS)

    Kiyama, Akihito; Kurihara, Chihiro; Tagawa, Yoshiyuki

    2015-11-01

    We study reasonable expression for predicting the onset of cavitation induced by an impact experimentally. A liquid-filled test tube is dropped and impacts a floor, followed by the emergence of cavitation bubbles inside a liquid. As floor materials, a metal and a resin are chosen. As a wetting liquid, gas-saturated silicone oil was used. Experiments are conducted at room temperature. The condition for cavitation occurrence for a resin floor cannot be described by the typical velocity measured by high-speed imaging, temporal resolution and spatial resolution of which are respectively O(10) μs and O(100) μm. We investigate sudden acceleration at the impact using an accelerometer. Its temporal resolution is O(1) ns, much smaller than that of high-speed imaging. The time history of acceleration for the resin floor is more moderate and peak acceleration is smaller than that for the metal floor. Based on these findings, we discuss the reasonable description of the criterion for the onset of cavitation bubbles, applicable for various floors. JSPS KAKENHI Grant Number 26709007.

  15. Blockade of Extracellular ATP Effect by Oxidized ATP Effectively Mitigated Induced Mouse Experimental Autoimmune Uveitis (EAU)

    PubMed Central

    Zhao, Ronglan; Liang, Dongchun; Sun, Deming

    2016-01-01

    Various pathological conditions are accompanied by ATP release from the intracellular to the extracellular compartment. Extracellular ATP (eATP) functions as a signaling molecule by activating purinergic P2 purine receptors. The key P2 receptor involved in inflammation was identified as P2X7R. Recent studies have shown that P2X7R signaling is required to trigger the Th1/Th17 immune response, and oxidized ATP (oxATP) effectively blocks P2X7R activation. In this study we investigated the effect of oxATP on mouse experimental autoimmune uveitis (EAU). Our results demonstrated that induced EAU in B6 mice was almost completely abolished by the administration of small doses of oxATP, and the Th17 response, but not the Th1 response, was significantly weakened in the treated mice. Mechanistic studies showed that the therapeutic effects involve the functional change of a number of immune cells, including dendritic cells (DCs), T cells, and regulatory T cells. OxATP not only directly inhibits the T cell response; it also suppresses T cell activation by altering the function of DCs and Foxp3+ T cell. Our results demonstrated that inhibition of P2X7R activation effectively exempts excessive autoimmune inflammation, which may indicate a possible therapeutic use in the treatment of autoimmune diseases. PMID:27196432

  16. Illusions and Delusions: Relating Experimentally-Induced False Memories to Anomalous Experiences and Ideas

    PubMed Central

    Corlett, Philip R.; Simons, Jon S.; Pigott, Jennifer S.; Gardner, Jennifer M.; Murray, Graham K.; Krystal, John H.; Fletcher, Paul C.

    2009-01-01

    The salience hypothesis of psychosis rests on a simple but profound observation that subtle alterations in the way that we perceive and experience stimuli have important consequences for how important these stimuli become for us, how much they draw our attention, how they embed themselves in our memory and, ultimately, how they shape our beliefs. We put forward the idea that a classical memory illusion – the Deese–Roediger–McDermott (DRM) effect – offers a useful way of exploring processes related to such aberrant belief formation. The illusion occurs when, as a consequence of its relationship to previous stimuli, a stimulus that has not previously been presented is falsely remembered. Such illusory familiarity is thought to be generated by the surprising fluency with which the stimulus is processed. In this respect, the illusion relates directly to the salience hypothesis and may share common cognitive underpinnings with aberrations of perception and attribution that are found in psychosis. In this paper, we explore the theoretical importance of this experimentally-induced illusion in relation to the salience model of psychosis. We present data showing that, in healthy volunteers, the illusion relates directly to self reported anomalies of experience and magical thinking. We discuss this finding in terms of the salience hypothesis and of a broader Bayesian framework of perception and cognition which emphasizes the salience both of predictable and unpredictable experiences. PMID:19956402

  17. Numerical and experimental study of the thermal stress of silicon induced by a millisecond laser

    SciTech Connect

    Wang Xi; Qin Yuan; Wang Bin; Zhang Liang; Shen Zhonghua; Lu Jian; Ni Xiaowu

    2011-07-20

    A spatial axisymmetric finite element model of single-crystal silicon irradiated by a 1064 nm millisecond laser is used to investigate the thermal stress damage induced by a millisecond laser. The transient temperature field and the thermal stress field for 2 ms laser irradiation with a laser fluence of 254 J/cm{sup 2} are obtained. The numerical simulation results indicate that the hoop stresses along the r axis on the front surface are compressive stress within the laser spot and convert to tensile stress outside the laser spot, while the radial stresses along the r axis on the front surface and on the z axis are compressive stress. The temperature of the irradiated center is the highest temperature obtained, yet the stress is not always highest during laser irradiation. At the end of the laser irradiation, the maximal hoop stress is located at r=0.5 mm and the maximal radial stress is located at r=0.76 mm. The temperature measurement experiments are performed by IR pyrometer. The numerical result of the temperature field is consistent with the experimental result. The damage morphologies of silicon under the action of a 254 J/cm{sup 2} laser are inspected by optical microscope. The cracks are observed initiating at r=0.5 mm and extending along the radial direction.

  18. A Protective Role of Arecoline Hydrobromide in Experimentally Induced Male Diabetic Rats

    PubMed Central

    Saha, Indraneel; Das, Joydeep; Maiti, Biswaranjan

    2015-01-01

    Objectives. Arecoline, the most potent and abundant alkaloid of betel nut, causes elevation of serum testosterone and androgen receptor expression in rat prostate, in addition to increase in serum insulin levels in rats, leading to insulin resistance and type 2 diabetes-like conditions. This study investigated the role of arecoline on the reproductive status of experimentally induced type 1 diabetic rats. Methods. Changes in the cellular architecture were analyzed by transmission electron microscopy. Blood glucose, serum insulin, testosterone, FSH, and LH were assayed. Fructose content of the coagulating gland and sialic acid content of the seminal vesicles were also analyzed. Results. Arecoline treatment for 10 days at a dose of 10 mg/kg of body weight markedly facilitated β-cell regeneration and reversed testicular and sex accessory dysfunctions by increasing the levels of serum insulin and gonadotropins in type 1 diabetic rats. Critical genes related to β-cell regeneration, such as pancreatic and duodenal homeobox 1 (pdx-1) and glucose transporter 2 (GLUT-2), were found to be activated by arecoline at the protein level. Conclusion. It can thus be suggested that arecoline is effective in ameliorating the detrimental effects caused by insulin deficiency on gonadal and male sex accessories in rats with type 1 diabetes. PMID:25695047

  19. Mitigation of DMBA-induced mammary carcinoma in experimental rats by antiangiogenic property of Kalpaamruthaa.

    PubMed

    Sathish, Sivaprakasam; Shanthi, Palanivelu; Sachdanandam, Panchanatham

    2011-06-01

    Extra cellular matrix (ECM) and basement membrane (BM) are important layers that regulate cell structure, cell migration, and cellular proliferation. Degradation of both ECM and BM mediated by proteases favors the tumor invasion and promotes angiogenesis. Female Sprague-Dawley rats weighing 180 ± 10 g were categorized into 6 groups. Group-1 animals served as vehicle control. Group-2 to Group-4 animals were administered with 7,12-dimethylbenz(a)anthracene (25 mg/rat dissolved in olive oil, orally) on day 1 of experimental period to induce mammary carcinoma. (After 90 days, mammary carcinoma was confirmed by histopathological examination). Group-3 and Group-4 rats were subsequently treated with Semecarpus anacardium nut milk extract (SA) and Kalpaamruthaa (KA), respectively. Group-5 and Group-6 animals served as drug control for SA and KA, respectively. Pro-angiogenic factors like proteases, cyclooxygenase-2, and vascular endothelial growth factor were elevated in tumor-bearing animals and decreased in SA- and KA-supplemented rats. Increased levels of these angiogenic factors in tumor-bearing rats indicate the progression of mammary tumor. The decreased levels of these angiogenic in SA- and KA-treated rats may be due to the ameliorative effect of phenolic compounds such as flavonoids, tannins, and other compounds present in the drug. PMID:22432686

  20. Use of laparoscopy for diagnosing experimentally induced acute pancreatitis in dogs

    PubMed Central

    Kim, Hyun-wook; Oh, Ye-in; Choi, Ji-hye; Kim, Dae-yong

    2014-01-01

    Diagnosis of acute pancreatitis in dogs remains a significant challenge despite the development of advanced diagnostic methodologies. Visual inspection and pancreas biopsy using laparoscopy are generally considered to be procedures free of complications when conducted on healthy animals. However, the usefulness of laparoscopy for diagnosing acute pancreatitis has not been assessed. In the present study, the efficacy of laparoscopy for diagnosing acute pancreatitis in dogs was evaluated in animals with experimentally induced acute pancreatitis. Gross appearance of the pancreatic area was examined by laparoscopy to survey for the presence of edema, adhesions, effusion, pseudocysts, hemorrhage, and fat necrosis. Laparoscopic biopsy was performed and the histopathologic results were compared to those of pancreatic samples obtained during necropsy. The correlation between laparoscopy and histopathologic findings of the pancreas was evaluated. The presence of adhesions, effusion, and hemorrhage in the pancreatic area observed by laparoscopy significantly correlated with the histopathologic results (p < 0.05). There was no significant relationship between the histopathologic and laparoscopic biopsy findings. Results of this study suggested that laparoscopic evaluation of gross lesions has clinical significance although the laparoscopic biopsy technique has some limitations. This method combined with additional diagnostic tools can be effective for diagnosing acute pancreatitis in dogs. PMID:24962411

  1. Experimental investigation of ultraviolet laser induced plasma density and temperature evolution in air

    SciTech Connect

    Thiyagarajan, Magesh; Scharer, John

    2008-07-01

    We present measurements and analysis of laser induced plasma neutral densities and temperatures in dry air by focusing 200 mJ, 10 MW high power, 193 nm ultraviolet ArF (argon fluoride) laser radiation to a 30 {mu}m radius spot size. We examine these properties that result from multiphoton and collisional cascade processes for pressures ranging from 40 Torr to 5 atm. A laser shadowgraphy diagnostic technique is used to obtain the plasma electron temperature just after the shock front and this is compared with optical emission spectroscopic measurements of nitrogen rotational and vibrational temperatures. Two-color laser interferometry is employed to measure time resolved spatial electron and neutral density decay in initial local thermodynamic equilibrium (LTE) and non-LTE conditions. The radiating species and thermodynamic characteristics of the plasma are analyzed by means of optical emission spectroscopy (OES) supported by SPECAIR, a special OES program for air constituent plasmas. Core plasma rotational and vibrational temperatures are obtained from the emission spectra from the N{sub 2}C-B(2+) transitions by matching the experimental spectrum results with the SPECAIR simulation results and the results are compared with the electron temperature just behind the shock wave. The plasma density decay measurements are compared with a simplified electron density decay model that illustrates the dominant three-and two-body recombination terms with good correlation.

  2. Experimental investigation of ultraviolet laser induced plasma density and temperature evolution in air

    NASA Astrophysics Data System (ADS)

    Thiyagarajan, Magesh; Scharer, John

    2008-07-01

    We present measurements and analysis of laser induced plasma neutral densities and temperatures in dry air by focusing 200 mJ, 10 MW high power, 193 nm ultraviolet ArF (argon fluoride) laser radiation to a 30 μm radius spot size. We examine these properties that result from multiphoton and collisional cascade processes for pressures ranging from 40 Torr to 5 atm. A laser shadowgraphy diagnostic technique is used to obtain the plasma electron temperature just after the shock front and this is compared with optical emission spectroscopic measurements of nitrogen rotational and vibrational temperatures. Two-color laser interferometry is employed to measure time resolved spatial electron and neutral density decay in initial local thermodynamic equilibrium (LTE) and non-LTE conditions. The radiating species and thermodynamic characteristics of the plasma are analyzed by means of optical emission spectroscopy (OES) supported by SPECAIR, a special OES program for air constituent plasmas. Core plasma rotational and vibrational temperatures are obtained from the emission spectra from the N2C-B(2+) transitions by matching the experimental spectrum results with the SPECAIR simulation results and the results are compared with the electron temperature just behind the shock wave. The plasma density decay measurements are compared with a simplified electron density decay model that illustrates the dominant three-and two-body recombination terms with good correlation.

  3. Induced Cannibalism in Experimental Populations of the Forensic Indicator Chrysomya putoria Wiedemann (Diptera: Calliphoridae).

    PubMed

    Botteon, V W; Fernandes, F S; Godoy, W A C

    2016-04-01

    We analyzed the behavior of third-instars of Chrysomya putoria as potential cannibals in experimental populations. Cannibalism rates were evaluated in three settings observed for 3, 6, 9, and 24 h, placing injured and uninjured larvae of C. putoria together. Our data heavily support that C. putoria larvae behave as cannibals when induced by a wound in another larva, and also after starving for 24 h. The probability of cannibalism increased as a function of time, both in no-choice and in choice experiments evidencing that time is a determining factor for cannibalism induction in C. putoria. However, the treatment combining injured with uninjured larvae showed the highest probability of cannibalism. These results suggest that C. putoria larvae may cannibalize under scarcity of food over long time or the presence of injured larvae. This study is useful to understand the behavior of C. putoria feeding on ephemeral substrates such as carrion or corpses and brings relevant and significant contribution to population ecology of blowflies and also forensic entomology. PMID:26698866

  4. Experimental setup and first measurement of DNA damage induced along and around an antiproton beam

    NASA Astrophysics Data System (ADS)

    Kavanagh, J. N.; Currell, F. J.; Timson, D. J.; Holzscheiter, M. H.; Bassler, N.; Herrmann, R.; Prise, K. M.; Schettino, G.

    2010-10-01

    Radiotherapy employs ionizing radiation to induce lethal DNA lesions in cancer cells while minimizing damage to healthy tissues. Due to their pattern of energy deposition, better therapeutic outcomes can, in theory, be achieved with ions compared to photons. Antiprotons have been proposed to offer a further enhancement due to their annihilation at the end of the path. The work presented here aimed to establish and validate an experimental procedure for the quantification of plasmid and genomic DNA damage resulting from antiproton exposure. Immunocytochemistry was used to assess DNA damage in directly and indirectly exposed human fibroblasts irradiated in both plateau and Bragg peak regions of a 126 MeV antiproton beam at CERN. Cells were stained post irradiation with an anti- γ-H2AX antibody. Quantification of the γ-H2AX foci-dose relationship is consistent with a linear increase in the Bragg peak region. A qualitative analysis of the foci detected in the Bragg peak and plateau region indicates significant differences highlighting the different severity of DNA lesions produced along the particle path. Irradiation of desalted plasmid DNA with 5 Gy antiprotons at the Bragg peak resulted in a significant portion of linear plasmid in the resultant solution.

  5. Experimental evidence for drought induced alternative stable states of soil moisture

    PubMed Central

    Robinson, David. A.; Jones, Scott B.; Lebron, Inma; Reinsch, Sabine; Domínguez, María T.; Smith, Andrew R.; Jones, Davey L.; Marshall, Miles R.; Emmett, Bridget A.

    2016-01-01

    Ecosystems may exhibit alternative stable states (ASS) in response to environmental change. Modelling and observational data broadly support the theory of ASS, however evidence from manipulation experiments supporting this theory is limited. Here, we provide long-term manipulation and observation data supporting the existence of drought induced alternative stable soil moisture states (irreversible soil wetting) in upland Atlantic heath, dominated by Calluna vulgaris (L.) Hull. Manipulated repeated moderate summer drought, and intense natural summer drought both lowered resilience resulting in shifts in soil moisture dynamics. The repeated moderate summer drought decreased winter soil moisture retention by ~10%. However, intense summer drought, superimposed on the experiment, that began in 2003 and peaked in 2005 caused an unexpected erosion of resilience and a shift to an ASS; both for the experimental drought manipulation and control plots, impairing the soil from rewetting in winter. Measurements outside plots, with vegetation removal, showed no evidence of moisture shifts. Further independent evidence supports our findings from historical soil moisture monitoring at a long-term upland hydrological observatory. The results herald the need for a new paradigm regarding our understanding of soil structure, hydraulics and climate interaction. PMID:26804897

  6. Modeling and simulation of organophosphate-induced neurotoxicity: Prediction and validation by experimental studies.

    PubMed

    Greget, Renaud; Dadak, Selma; Barbier, Laure; Lauga, Fabien; Linossier-Pierre, Sandra; Pernot, Fabien; Legendre, Arnaud; Ambert, Nicolas; Bouteiller, Jean-Marie; Dorandeu, Frédéric; Bischoff, Serge; Baudry, Michel; Fagni, Laurent; Moussaoui, Saliha

    2016-05-01

    Exposure to organophosphorus (OP) compounds, either pesticides or chemical warfare agents, represents a major health problem. As potent irreversible inhibitors of cholinesterase, OP may induce seizures, as in status epilepticus, and occasionally brain lesions. Although these compounds are extremely toxic agents, the search for novel antidotes remains extremely limited. In silico modeling constitutes a useful tool to identify pharmacological targets and to develop efficient therapeutic strategies. In the present work, we developed a new in silico simulator in order to predict the neurotoxicity of irreversible inhibitors of acetyl- and/or butyrylcholinesterase (ChE) as well as the potential neuroprotection provided by antagonists of cholinergic muscarinic and glutamate N-methyl-d-aspartate (NMDA) receptors. The simulator reproduced firing of CA1 hippocampal neurons triggered by exposure to paraoxon (POX), as found in patch-clamp recordings in in vitro mouse hippocampal slices. In the case of POX intoxication, it predicted a preventing action of the muscarinic receptor antagonist atropine sulfate, as well as a synergistic action with the non-competitive NMDA receptor antagonist memantine. These in silico predictions relative to beneficial effects of atropine sulfate combined with memantine were recapitulated experimentally in an in vivo model of POX in adult male Swiss mice using electroencephalic (EEG) recordings. Thus, our simulator is a new powerful tool to identify protective therapeutic strategies against OP central effects, by screening various combinations of muscarinic and NMDA receptor antagonists. PMID:27108687

  7. Experimental characterization of fire-induced response of rigid polyurethane foam

    SciTech Connect

    Chu, T.Y.; Gill, W.; Moore, J.W.; Hobbs, M.L.; Gritzo, L.A.; Moya, J.L.

    1995-12-31

    Reported is the result of an experimental investigation of fire-induced response of a 96 kg/m{sup 3} closed cell rigid polyurethane foam. The specimen is 0.37 m in diameter, and 152 mm thick, placed in a cylindrical test vessel. The fire condition is simulated by heating the bottom of the test vessel to 1283 K using a radiant heat source. Real-time x-ray shows that the degradation process involves the progression of a charring front into the virgin material. The charred region has a regular and graded structure consisting of a packed bubble outer layer and successive layers of thin shells. The layer-to-layer permeability appears to be poor. There are indications that gas vents laterally. The shell-like structure might be the result of lateral venting. Although the foam degradation process is quite complicated, the in-depth temperature responses in the uncharted foam appear to be consistent with steady state ablation. The measured temperature responses are well represented by the exponential distribution for steady state ablation. An estimate of the thermal diffusivity of the foam is obtained from the ablation model. The experiment is part of a more comprehensive program to develop material response models of foams and encapsulants.

  8. Experimental evidence for drought induced alternative stable states of soil moisture.

    PubMed

    Robinson, David A; Jones, Scott B; Lebron, Inma; Reinsch, Sabine; Domínguez, María T; Smith, Andrew R; Jones, Davey L; Marshall, Miles R; Emmett, Bridget A

    2016-01-01

    Ecosystems may exhibit alternative stable states (ASS) in response to environmental change. Modelling and observational data broadly support the theory of ASS, however evidence from manipulation experiments supporting this theory is limited. Here, we provide long-term manipulation and observation data supporting the existence of drought induced alternative stable soil moisture states (irreversible soil wetting) in upland Atlantic heath, dominated by Calluna vulgaris (L.) Hull. Manipulated repeated moderate summer drought, and intense natural summer drought both lowered resilience resulting in shifts in soil moisture dynamics. The repeated moderate summer drought decreased winter soil moisture retention by ~10%. However, intense summer drought, superimposed on the experiment, that began in 2003 and peaked in 2005 caused an unexpected erosion of resilience and a shift to an ASS; both for the experimental drought manipulation and control plots, impairing the soil from rewetting in winter. Measurements outside plots, with vegetation removal, showed no evidence of moisture shifts. Further independent evidence supports our findings from historical soil moisture monitoring at a long-term upland hydrological observatory. The results herald the need for a new paradigm regarding our understanding of soil structure, hydraulics and climate interaction. PMID:26804897

  9. Experimental evidence for drought induced alternative stable states of soil moisture

    NASA Astrophysics Data System (ADS)

    Robinson, David. A.; Jones, Scott B.; Lebron, Inma; Reinsch, Sabine; Domínguez, María T.; Smith, Andrew R.; Jones, Davey L.; Marshall, Miles R.; Emmett, Bridget A.

    2016-01-01

    Ecosystems may exhibit alternative stable states (ASS) in response to environmental change. Modelling and observational data broadly support the theory of ASS, however evidence from manipulation experiments supporting this theory is limited. Here, we provide long-term manipulation and observation data supporting the existence of drought induced alternative stable soil moisture states (irreversible soil wetting) in upland Atlantic heath, dominated by Calluna vulgaris (L.) Hull. Manipulated repeated moderate summer drought, and intense natural summer drought both lowered resilience resulting in shifts in soil moisture dynamics. The repeated moderate summer drought decreased winter soil moisture retention by ~10%. However, intense summer drought, superimposed on the experiment, that began in 2003 and peaked in 2005 caused an unexpected erosion of resilience and a shift to an ASS; both for the experimental drought manipulation and control plots, impairing the soil from rewetting in winter. Measurements outside plots, with vegetation removal, showed no evidence of moisture shifts. Further independent evidence supports our findings from historical soil moisture monitoring at a long-term upland hydrological observatory. The results herald the need for a new paradigm regarding our understanding of soil structure, hydraulics and climate interaction.

  10. Hazard of CO₂ laser-induced airway fire in laryngeal surgery: experimental data of contributing factors.

    PubMed

    Stuermer, Konrad Johannes; Ayachi, Stefan; Gostian, Antoniu-O; Beutner, Dirk; Hüttenbrink, Karl-Bernd

    2013-09-01

    In carbon dioxide (CO2) laser surgery of the larynx, the potentially dangerous combination of laser-induced heat in an oxygen-enriched atmosphere typically occurs when jet ventilation is used or due to an insufficiently blocked endotracheal tube. Until now, no limitations for safe oxygen concentrations or laser intervals have been established. The aim of this study was to investigate and quantify the factors that may contribute to an airway fire in laryngeal laser surgery. Fat, muscle and cartilage were irradiated with a CO2 laser at 2, 4, 6 and 8 W in five different oxygen concentrations with and without smoke exhaustion. The time to ignition was recorded for each different experimental setup. Fat burnt fastest, followed by cartilage and muscle. The elevation of laser energy or oxygen concentration reduced the time to inflammation of any tissue. The elevation of oxygen by 10 % increases the risk of inflammation more than the elevation of laser power by 2 W. Under smoke exhaustion, inflammation and burning occurred delayed or were even inhibited at lower oxygen concentrations. Lasing in more than 50 % oxygen is comparatively dangerous and can cause airway fire in less than 5 s, especially when laser energies of more than 5 W are applied. In equal or lower than 50 % oxygen, an irradiation interval of 5 s can be considered a comparatively safe time limit to prevent inflammation in laryngeal laser surgery. Smoke exhaustion should always be applied. PMID:23636479

  11. An Experimental Study of Roughness-Induced Instabilities in a Supersonic Boundary Layer

    NASA Technical Reports Server (NTRS)

    Kegerise, Michael A.; King, Rudolph A.; Choudhari, Meelan; Li, Fei; Norris, Andrew

    2014-01-01

    Progress on an experimental study of laminar-to-turbulent transition induced by an isolated roughness element in a supersonic laminar boundary layer is reported in this paper. Here, the primary focus is on the effects of roughness planform shape on the instability and transition characteristics. Four different roughness planform shapes were considered (a diamond, a circle, a right triangle, and a 45 degree fence) and the height and width of each one was held fixed so that a consistent frontal area was presented to the oncoming boundary layer. The nominal roughness Reynolds number was 462 and the ratio of the roughness height to the boundary layer thickness was 0.48. Detailed flow- field surveys in the wake of each geometry were performed via hot-wire anemometry. High- and low-speed streaks were observed in the wake of each roughness geometry, and the modified mean flow associated with these streak structures was found to support a single dominant convective instability mode. For the symmetric planform shapes - the diamond and circular planforms - the instability characteristics (mode shapes, growth rates, and frequencies) were found to be similar. For the asymmetric planform shapes - the right-triangle and 45 degree fence planforms - the mode shapes were asymmetrically distributed about the roughness-wake centerline. The instability growth rates for the asymmetric planforms were lower than those for the symmetric planforms and therefore, transition onset was delayed relative to the symmetric planforms.

  12. Experimental investigation on vortex-induced vibration of steel catenary riser

    NASA Astrophysics Data System (ADS)

    Fan, Yu-ting; Mao, Hai-ying; Guo, Hai-yan; Liu, Qing-hai; Li, Xiao-min

    2015-10-01

    Steel catenary riser (SCR) is the transmission device between the seabed and the floating production facilities. As developments move into deeper water, the fatigue life of the riser can become critical to the whole production system, especially due to the vortex-induced vibration (VIV), which is the key factor to operational longevity. As a result, experimental investigation about VIV of the riser was performed in a large plane pool which is 60 m long, 36 m wide and 6.5 m deep. Experiments were developed to study the influence of current speed and seabed on VIV of SCR. The results show that amplitudes of strain and response frequencies increase with the current speed both in cross-flow (CF) and in-line (IL). When the current speed is high, multi-mode response is observed in the VIV motion. The amplitudes of strain in IL direction are not much smaller than those in CF direction. The seabed has influence on the response frequencies of riser and the positions of damage for riser.

  13. Experimental Study of Overtopping Induced Landslide Dam Break Flow and Two Layer Two Phase Mixture Model

    NASA Astrophysics Data System (ADS)

    Liu, L.; Duan, J. G.; Zhong, D.; Zhang, H.

    2013-12-01

    A series of experiments were conducted to investigate flood flow generated by the failure of landslide dams due to overtopping. These experiments aim to quantify the influences of inflow discharge, downstream slope, width of dam crest, dam height, and dam material on the flood flow. Images from high-speed cameras are used to determine the profiles of dam body and flow discharge during the failure processes. Results showed that the water level in the upstream reservoir and the erosion of dam body are the dominant factors affecting the downstream flood flow. A physical-based model is established to calculate the arriving time and the peak discharge of dam break flow using two phase mixture model. Both analytical and numerical solutions were derived for the model. The modelling results were verified using data from this and several other laboratory experimental datasets. The agreement between the calculated and measured data showed the applicability of the proposed model for predicting the peak discharge of overtopping induced dam break flow.

  14. Multimerized T cell epitopes protect from experimental autoimmune diabetes by inducing dominant tolerance.

    PubMed

    Piaggio, Eliane; Mars, Lennart T; Cassan, Cécile; Cabarrocas, Julie; Hofstätter, Maria; Desbois, Sabine; Bergereau, Emilie; Rötzschke, Olaf; Falk, Kirsten; Liblau, Roland S

    2007-05-29

    Immunotherapy by using multimerized self-peptides has demonstrated a clear protective effect on experimental models of autoimmune diseases. However, the mechanisms involved remain ill-defined. Here we have evaluated the therapeutic efficacy of multimerized self-peptides at the effector phase of autoimmune diabetes and examined their mechanisms of action. Diabetes was induced in rat insulin promoter-hemagglutinin (HA) mice expressing HA in pancreatic beta-cells by adoptive transfer of HA(110-119)-specific T helper 1 cells. Complete protection was provided by low doses of the HA 4-mer consisting of four covalently linked linear HA(107-119) peptides. In vivo, the 4-mer appeared to act directly on the pathogenic HA-specific T helper 1 cells and indirectly by activation/recruitment of lymphocytes with regulatory properties so that mice became resistant to a second transfer of diabetogenic T cells. This effect was associated with a recruitment of Foxp3(+) CD4 T cells around islets. Moreover, we show that dominant protection from autoimmunity was transferable by spleen cells, and that development of this regulatory population was crucially dependent on the lymphocytes from treated rat insulin promoter-HA mice. Thus, immunotherapy using multimerized epitopes emerges as a promising strategy in view of the current identification of self-epitopes that are major targets of the pathogenic CD4 T cell response in autoimmune diseases. PMID:17517665

  15. Multimerized T cell epitopes protect from experimental autoimmune diabetes by inducing dominant tolerance

    PubMed Central

    Piaggio, Eliane; Mars, Lennart T.; Cassan, Cécile; Cabarrocas, Julie; Hofstätter, Maria; Desbois, Sabine; Bergereau, Emilie; Rötzschke, Olaf; Falk, Kirsten; Liblau, Roland S.

    2007-01-01

    Immunotherapy by using multimerized self-peptides has demonstrated a clear protective effect on experimental models of autoimmune diseases. However, the mechanisms involved remain ill-defined. Here we have evaluated the therapeutic efficacy of multimerized self-peptides at the effector phase of autoimmune diabetes and examined their mechanisms of action. Diabetes was induced in rat insulin promoter-hemagglutinin (HA) mice expressing HA in pancreatic β-cells by adoptive transfer of HA110–119-specific T helper 1 cells. Complete protection was provided by low doses of the HA 4-mer consisting of four covalently linked linear HA107–119 peptides. In vivo, the 4-mer appeared to act directly on the pathogenic HA-specific T helper 1 cells and indirectly by activation/recruitment of lymphocytes with regulatory properties so that mice became resistant to a second transfer of diabetogenic T cells. This effect was associated with a recruitment of Foxp3+ CD4 T cells around islets. Moreover, we show that dominant protection from autoimmunity was transferable by spleen cells, and that development of this regulatory population was crucially dependent on the lymphocytes from treated rat insulin promoter-HA mice. Thus, immunotherapy using multimerized epitopes emerges as a promising strategy in view of the current identification of self-epitopes that are major targets of the pathogenic CD4 T cell response in autoimmune diseases. PMID:17517665

  16. [A study of epidermal alterations induced by PCDF on experimental carcinogenesis].

    PubMed

    Hirose, R; Hori, M; Toyoshima, H; Shukuwa, T; Udono, M; Yoshida, H

    1991-05-01

    An effect of 2,3,4,7,8-pentachlorodibenzofuran (PCDF) as a promoter on a course of experimental skin carcinogenesis in mice by chemicals 20-methylcholanthrene (MC) has been proved by our previous studies. Details of ultrastructural epidermal alterations induced by MC and PCDF were observed and an attempt to differentiate benign tumor from malignant one in which a combined application of MC and PCDF on mice skin resulted was done electron microscopically. Four significant findings as follows were detected. First of all even the epidermal cells without tumor had some atypicality. Secondly both of benign tumor and normal-appeared skin without tumor had giant and round-shaped keratohyalin granules (KHGs) which show a tendency of less keratinization. Thirdly cytoplasmic projections of epidermal cells increased in number and sparse tonofilaments scattered in the cytoplasm of benign tumor. This is also an appearance of mucous metaplasia of keratinocytes as well as the form of KHGs mentioned above. Finally benign tumor had thick horny cells including numerous lipid droplets, and that is a sign of acceleration of epidermal turn over. Since epidermal cells have little chance to be exposed to carcinogens when they quickly keratinize, they rarely form a cancer. When epidermal cells have such tendency as less keratinization or more keratinization, they are supposed to be less sensitive to any stimuli of carcinogens, and consequently they incline to be benign tumor instead of malignant one. PMID:1916594

  17. Protective effects of D-002 on experimentally induced gastroesophageal reflux in rats

    PubMed Central

    Zamora, Zullyt; Molina, Vivian; Mas, Rosa; Ravelo, Yazmin; Perez, Yohany; Oyarzabal, Ambar

    2014-01-01

    AIM: To investigate the effects of beeswax alcohols (D-002) on the esophageal damage induced by gastroesophageal reflux (GER) in rats. METHODS: Sixty male rats were randomized into six groups (10 rats/group): a negative control and five groups with experimentally induced GER: a positive vehicle control, three treated with D-002 (25, 100 and 200 mg/kg, respectively), and one with omeprazole 10 mg/kg. All treatments were given by gastric gavage. One hour after dosing, GER was produced by simultaneous ligation of the pyloric end and the forestomach. Esophageal lesions index (ELI), gastric secretion volume and acidity, and esophageal malondialdehyde (MDA) and sulfhydryl (SH) group concentrations were measured. Statistical significance was considered at P < 0.05. RESULTS: As compared to the negative control, the positive control group exhibited increased ELI (5.2 ± 0.33 vs 0 ± 0, P = 0.0003), gastric secretion volume (2.69 ± 0.09 vs 0.1 ± 0.0, P = 0.0003) and acidity (238 ± 19.37 vs 120.0 ± 5.77, P = 0.001), and esophageal concentrations of MDA (2.56 ± 0.1 vs 1.76 ± 0.28, P = 0.001) and SH groups (1.02 ± 0.05 vs 0.56 ± 0.08, P = 0.0003). D-002 (25, 100 and 200 mg/kg) reduced ELI (3.36 ± 0.31, 2.90 ± 0.46 and 2.8 ± 0.23, respectively) vs the positive control (5.2 ± 0.33) (P = 0.004; P = 0.002; P = 0.001, respectively). There were no significant changes in acidity with D-002 treatment, and only the highest dose reduced the volume of the gastric secretion (1.92 ± 0.25) vs the positive control (2.69 ± 0.09, P = 0.013). D-002 (25, 100 and 200 mg/kg) lowered the esophageal MDA (2.05 ± 0.16, 1.98 ± 0.22 and 1.93 ± 0.22, respectively) (P = 0.01; P = 0.03; P = 0.03, respectively) and SH group concentration (0.87 ± 0.06, 0.79 ± 0.08 and 0.77 ± 0.06, respectively) (P = 0.04; P = 0.04; P = 0.02) vs the positive control (2.56 ± 0.10 and 1.02 ± 0.05, respectively). Omeprazole decreased ELI (2.54 ± 0.47), gastric secretion volume (1.97 ± 0.14) and acidity

  18. Heat-induced evaporation in the shallow subsurface: Experimental and modeling investigation

    NASA Astrophysics Data System (ADS)

    Smits, K. M.; Cihan, A.; Sakaki, T.; Illangasekare, T. H.

    2009-12-01

    The simultaneous movement of liquid water, water vapor and heat in the shallow subsurface below the land-atmosphere interface plays a critical role in determining the mass and energy fluxes between the soil surface and the atmosphere in many agricultural and engineering practices. In arid and semiarid regions, temperature gradients can be very large and the transfer of water due to temperature fluctuations and evaporative conditions may have a significant effect on soil water distributions. Although it is widely recognized that liquid water, water vapor and heat are closely coupled, their mutual interactions are rarely considered in most soil water modeling efforts or in practical application. The validation of numerical models that are designed to capture these processes is difficult due to the inherent complexities of the problem and the scarcity of laboratory data with accurately known hydraulic and thermal parameters, thus limiting the testing and refinement of heat and water transfer theory. In this work, we first developed a long column apparatus equipped with a network of recent sensor technologies. Data were then generated under well-controlled transient heat boundary conditions with a goal of validating the coupled heat-mass transport model and assessing fundamental processes. The objectives of this work were to (1) develop an experimental setup in order to generate precision data (2) develop and implement a fully coupled numerical model to solve for heat, liquid water and water vapor flux (3) determine the key model parameters and processes in order to find the simplest mathematical relationship that best describes the experimental system. For this experimental investigation, very uniform sand was used to minimize particle segregation during packing and achieve as uniform packing as possible. Water saturation, capillary pressure, temperature, relative humidity and column weight were continuously monitored. Evaporation was induced at the soil surface by

  19. Analytical and experimental study of mean flow and turbulence characteristics inside the passages of an axial flow inducer

    NASA Technical Reports Server (NTRS)

    Gorton, C. A.; Lakshminarayana, B.

    1974-01-01

    The effort conducted to gather additional understanding of the complex inviscid and viscid effects existing within the passages of a three-bladed axial flow inducer operating at a flow coefficient of 0.065 is summarized. The experimental investigations included determination of the blade static pressure and blade limiting streamline angle distributions, and measurement of the three components of mean velocity, turbulence intensities and turbulence stresses at locations inside the inducer blade passage utilizing a rotating three-sensor hotwire probe. Applicable equations were derived for the hotwire data reduction analysis and solved numerically to obtain the appropriate flow parameters. Analytical investigations were conducted to predict the three-dimensional inviscid flow in the inducer by numerically solving the exact equations of motion, and to approximately predict the three-dimensional viscid flow by incorporating the dominant viscous terms into the exact equations. The analytical results are compared with the experimental measurements and design values where appropriate.

  20. Experimental Study on the Vortex-Induced Vibration of Towed Pipes

    NASA Astrophysics Data System (ADS)

    HONG, S.; CHOI, Y. R.; PARK, J.-B.; PARK, Y.-K.; KIM, Y.-H.

    2002-01-01

    We experimentally attempted to understand the vibration characteristics of a flexible pipe excited by vortex shedding. This has been extensively studied in the previous decades (for example, see Sarpkaya 1979 Journal of Applied Mechanics46, 241-258; Price et al. 1989 Eighth International Conference on Offshore Mechanics and Arctic Engineering, The Hague-March 19 -23, 447-454; Yoerger et al. 1991 Journal of Offshore Mechanics and Arctic Engineering, Transaction of Engineers113, 117-127; Grosenbaugh et al. 1991Journal of Offshore Mechanics and Arctic Engineering, Transaction of Engineers113 , 199-204; Brika and Laneville 1992 Journal of Fluid Mechanics250, 481-508; Chakrabarti et al. 1993 Ocean Engineering20, 135-162; Jong 1983 Ph.D. Dissertation, Department of Ocean Engineering, M. I. T.; Kimet al. 1986 Journal of Energy Resources Technology, Transactions of American Society of Mechanical Engineers108, 77-83). However, there are still areas that need more study. One of them is the relation between spatial characteristics of a flow-induced vibrating pipe, such as its length, the distribution of wave number, and frequency responses. A non-linear mechanism between the responses of in-line and cross-flow directions is also an area of interest, if the pipe is relatively long so that structural modal density is reasonably high. In order to investigate such areas, two kinds of instrumented pipe were designed. The instrumented pipes, of which the lengths are equally 6 m, are wound with rubber and silicon tape in different ways, having different vortex-shedding conditions. One has uniform cross-section of diameter of 26·7 mm, and the other has equally spaced four sub-sections, which are composed of different diameters of 75·9, 61·1, 45·6 and 26·7 mm. Both pipes are towed in a water tank (200 m×16 m×7 m) so that they experienced different vortex-shedding excitations. Various measures were obtained from the towing experiment, including frequency responses, the time

  1. Experimental animal models for studies on the mechanisms of blast-induced neurotrauma.

    PubMed

    Risling, Mårten; Davidsson, Johan

    2012-01-01

    A blast injury is a complex type of physical trauma resulting from the detonation of explosive compounds and has become an important issue due to the use of improvised explosive devices (IED) in current military conflicts. Blast-induced neurotrauma (BINT) is a major concern in contemporary military medicine and includes a variety of injuries that range from mild to lethal. Extreme forces and their complex propagation characterize BINT. Modern body protection and the development of armored military vehicles can be assumed to have changed the outcome of BINT. Primary blast injuries are caused by overpressure waves whereas secondary, tertiary, and quaternary blast injuries can have more varied origins such as the impact of fragments, abnormal movements, or heat. The characteristics of the blast wave can be assumed to be significantly different in open field detonations compared to explosions in a confined space, such an armored vehicle. Important parameters include peak pressure, duration, and shape of the pulse. Reflections from walls and armor can make the prediction of effects in individual cases very complex. Epidemiological data do not contain information of the comparative importance of the different blast mechanisms. It is therefore important to generate data in carefully designed animal models. Such models can be selective reproductions of a primary blast, penetrating injuries from fragments, acceleration movements, or combinations of such mechanisms. It is of crucial importance that the physical parameters of the employed models are well characterized so that the experiments can be reproduced in different laboratory settings. Ideally, pressure recordings should be calibrated by using the same equipment in several laboratories. With carefully designed models and thoroughly evaluated animal data it should be possible to achieve a translation of data between animal and clinical data. Imaging and computer simulation represent a possible link between experiments

  2. The influence of age and genetics on natural resistance to experimentally induced feline infectious peritonitis.

    PubMed

    Pedersen, Niels C; Liu, Hongwei; Gandolfi, Barbara; Lyons, Leslie A

    2014-11-15

    Naturally occurring feline infectious peritonitis (FIP) is usually fatal, giving the impression that immunity to the FIP virus (FIPV) is extremely poor. This impression may be incorrect, because not all cats experimentally exposed to FIPV develop FIP. There is also a belief that the incidence of FIP may be affected by a number of host, virus, and environmental cofactors. However, the contribution of these cofactors to immunity and disease incidence has not been determined. The present study followed 111 random-bred specific pathogen free (SPF) cats that were obtained from a single research breeding colony and experimentally infected with FIPV. The cats were from several studies conducted over the past 5 years, and as a result, some of them had prior exposure to feline enteric coronavirus (FECV) or avirulent FIPVs. The cats were housed under optimized conditions of nutrition, husbandry, and quarantine to eliminate most of the cofactors implicated in FIPV infection outcome and were uniformly challenge exposed to the same field strain of serotype 1 FIPV. Forty of the 111 (36%) cats survived their initial challenge exposure to a Type I cat-passaged field strains of FIPV. Six of these 40 survivors succumbed to FIP to a second or third challenge exposure, suggesting that immunity was not always sustained. Exposure to non-FIP-inducing feline coronaviruses prior to challenge with virulent FIPV did not significantly affect FIP incidence but did accelerate the disease course in some cats. There were no significant differences in FIP incidence between males and females, but resistance increased significantly between 6 months and 1 or more years of age. Genetic testing was done on 107 of the 111 infected cats. Multidimensional scaling (MDS) segregated the 107 cats into three distinct families based primarily on a common sire(s), and resistant and susceptible cats were equally distributed within each family. Genome-wide association studies (GWAS) on 73 cats that died of FIP

  3. Experimental investigation of flow-induced vibration on isolated and tandem circular cylinders fitted with strakes

    NASA Astrophysics Data System (ADS)

    Korkischko, I.; Meneghini, J. R.

    2010-05-01

    The effect of varying the geometric parameters of helical strakes on vortex-induced vibration (VIV) is investigated in this paper. The degree of oscillation attenuation or even suppression is analysed for isolated circular cylinder cases. How a cylinder fitted with strakes behaves when immersed in the wake of another cylinder in tandem arrangement is also investigated and these results are compared to those with a single straked cylinder. The experimental tests are conducted at a circulating water channel facility and the cylindrical models are mounted on a low-damping air bearing elastic base with one degree-of-freedom, restricted to oscillate in the transverse direction to the channel flow. Three strake pitches (p) and heights (h) are tested: p=5, 10, 15d, and h=0.1, 0.2, 0.25d. The mass ratio is 1.8 for all models. The Reynolds number range is from 1000 to 10 000, and the reduced velocity varies up to 21. The cases with h=0.1d strakes reduce the amplitude response when compared to the isolated plain cylinder, however the oscillation still persists. On the other hand, the cases with h=0.2, 0.25d strakes almost completely suppress VIV. Spanwise vorticity fields, obtained through stereoscopic digital particle image velocimetry (SDPIV), show an alternating vortex wake for the p=10d and h=0.1d straked cylinder. The p=10d and h=0.2d cylinder wake has separated shear layers with constant width and no roll-up close to the body. The strakes do not increase the magnitude of the out-of-plane velocity compared to the isolated plain cylinder. However, they deflect the flow in the out-of-plane direction in a controlled way, which can prevent the vortex shedding correlation along the span. In order to investigate the wake interference effect on the strake efficiency, an experimental arrangement with two cylinders in tandem is employed. The centre-to-centre distance for the tandem arrangement varies from 2 to 6. When the downstream p=10d and h=0.2d cylinder is immersed in the

  4. Experimental Animal Models for Studies on the Mechanisms of Blast-Induced Neurotrauma

    PubMed Central

    Risling, Mårten; Davidsson, Johan

    2012-01-01

    A blast injury is a complex type of physical trauma resulting from the detonation of explosive compounds and has become an important issue due to the use of improvised explosive devices (IED) in current military conflicts. Blast-induced neurotrauma (BINT) is a major concern in contemporary military medicine and includes a variety of injuries that range from mild to lethal. Extreme forces and their complex propagation characterize BINT. Modern body protection and the development of armored military vehicles can be assumed to have changed the outcome of BINT. Primary blast injuries are caused by overpressure waves whereas secondary, tertiary, and quaternary blast injuries can have more varied origins such as the impact of fragments, abnormal movements, or heat. The characteristics of the blast wave can be assumed to be significantly different in open field detonations compared to explosions in a confined space, such an armored vehicle. Important parameters include peak pressure, duration, and shape of the pulse. Reflections from walls and armor can make the prediction of effects in individual cases very complex. Epidemiological data do not contain information of the comparative importance of the different blast mechanisms. It is therefore important to generate data in carefully designed animal models. Such models can be selective reproductions of a primary blast, penetrating injuries from fragments, acceleration movements, or combinations of such mechanisms. It is of crucial importance that the physical parameters of the employed models are well characterized so that the experiments can be reproduced in different laboratory settings. Ideally, pressure recordings should be calibrated by using the same equipment in several laboratories. With carefully designed models and thoroughly evaluated animal data it should be possible to achieve a translation of data between animal and clinical data. Imaging and computer simulation represent a possible link between experiments

  5. CT and MRI of experimentally induced mesenteric ischemia in a porcine model

    SciTech Connect

    Klein, H.M.; Seggewib, C.; Weghaus, P.; Kamp, M.; Guenther, R.W.

    1996-03-01

    Our goal was to assess the value of CT and MRI for the detection of bowel wall changes in experimentally induced mesenteric ischemia. In 18 female pigs. a percutaneous embolization of the superior mesenteric artery was performed with buthyl-2-cyanoacrylate and Lipoidal (1:1) (experimental group). In six animals, only diagnostic imaging and histologic evaluation were performed (control group). CT was carried out 3, 6, and 12 h after occlusion. Incremental CT (1 s scan time, 5 mm slice thickness, 7 mm increment, 120 kV/290 mAs) and spiral CT (slice thickness 5 mm, pitch 1.5, 120 kV/165 mA) were performed pre and post contrast injection (Somatom Plus/ Siemens). Serial CT was carried out after intravenous contrast injection (I ml/kg, 2 ml/s). MRI (Magnetom 1.5 T: Siemens) was performed with T1 (pre and post 0.01 mmol/kg Gd-DTPA; Magnevist; Schering. Germany), T2, and proton density images in axial orientation. Slice thickness was 3 mm and slice gap 1 mm. Additionally, a T1-weighted GE sequence was obtained in dynamic technique (before and 30, 60, and 90 s after contrast agent injection) with a slice thickness of 5 mm. Biometrical monitoring included blood pressure, heart frequency, blood cell count, electrolyte status, blood gas analysis, and determination of serum lactate. Image evaluation included morphological analysis and determination of the enhancement pattern. Histological specimens were obtained and analyzed according to the Chiu classification. The histologic workup of the specimen 3, 6, and 12 h after vascular occlusion revealed an average Chiu state 3, 4, and 5. On CT, the bowel wall had a thickness of 4.7 mm on average in the ischemic segments. There was a significant difference from the control group. Free intraperitoneal fluid and intramural gas were seen after 12 h of ischemia in 80%. In ischemic bowel segments, no mural enhancement was seen. Normal segments and the bowel of the control animals showed an enhancement of 34 HU on average.

  6. Analytical and experimental study of mean flow and turbulence characteristics inside the passages of an axial flow inducer

    NASA Technical Reports Server (NTRS)

    Gorton, C. A.; Lakshminarayana, B.

    1980-01-01

    The inviscid and viscid effects existing within the passages of a three bladed axial flow inducer operating at a flow coefficient of 0.065 are investigated. The blade static pressure and blade limiting streamline angle distributions were determined and the three components of mean velocity, turbulence intensities, and turbulence stresses were measured at locations inside the inducer blade passage utilizing a rotating three sensor hotwire probe. Applicable equations were derived for the hotwire data reduction analysis and solved numerically to obtain the appropriate flow parameters. The three dimensional inviscid flow in the inducer was predicted by numerically solving the exact equations of motion, and the three dimensional viscid flow was predicted by incorporating the dominant viscous terms into the exact equations. The analytical results are compared with the experimental measurements and design values where appropriate. Radial velocities are found to be of the same order as axial velocities within the inducer passage, confirming the highly three dimensional characteristic of inducer flow. Total relative velocity distribution indicate a substantial velocity deficiency near the tip at mid-passage which expands significantly as the flow proceeds toward the inducer trailing edge. High turbulence intensities and turbulence stresses are concentrated within this core region. Considerable wake diffusion occurs immediately downstream of the inducer trailing edge to decay this loss core. Evidence of boundary layer interactions, blade blockage effects, radially inward flows, annulus wall effects, and backflows are all found to exist within the long, narrow passages of the inducer.

  7. Combination treatment of lycopene and hesperidin protect experimentally induced ulcer in laboratory rats

    PubMed Central

    Jain, Dilpesh; Katti, Neha

    2015-01-01

    Aim: Lycopene, a carotenoid and hesperidin, a flavonoid are naturally occurring in vegetables and fruits. Synergistic effect of a combination of carotenoid and flavonoid has been reported due to its antioxidant activity. Therefore, the present study was aimed to evaluate the protective effect of this combination on pylorus ligation induced ulcers in rats. Materials and Methods: Thirty Wistar albino rats were divided into five groups (n = 6). Rats were fasted for 24 h before pylorus ligation. After 24 h of fasting the rats were treated with hesperidin (100 mg/kg) and lycopene (2 mg/kg) and their combination 1h prior to surgery. After an hour under ether anesthesia pylorus ligation was performed, after 5 h the animals were sacrificed, stomach was dissected, and gastric contents were collected and measured. Total acidity and pH of gastric content was estimated. Ulcer index was calculated, and macroscopic examination of the stomach was carried out. Results: The sham operated rats showed a significant increase in pH, volume of gastric content and total acidity and ulcer index. The rats pretreated with lycopene and hesperidin showed significant improvement in the ulcer conditions. However, rats treated with a combination of lycopene and hesperidin showed more significant restoration of gastric function as compared to sham operated rats. Moreover, a significant difference was also noted in rats treated with a combination as compared to lycopene and hesperidin treatment alone. Conclusion: Thus experimentally the combination was seen to treat ulcers by anti-secretory, neutralizing, cytoprotective and mainly due to its antioxidant property. PMID:26401402

  8. Computational and experimental study of flow-induced vibration of the SSME main injector post

    SciTech Connect

    Chen, S.S.; Jendrzejczyk, J.A.; Wambsganss, M.W.

    1986-01-01

    The Space Shuttle Main Engine (SSME) liquid-oxygen (LOX) posts are subjected to high-velocity turbulent flow from the transfer ducts. In a preliminary assessment of the vibration problem, it was determined that the two potential excitation mechanisms for LOX post vibration are fluidelastic instability and turbulent buffeting. A fundamental study is being conducted to understand the problem and to develop techniques to avoid detrimental vibrational effects with the objective of improving engine life. This paper summarizes the results of an analytical model for fluidelastic instability and test results for turbulent buffeting of a tube array in crossflow. A general theory of fluidelastic instability for a tube array in crossflow is presented. Various techniques to obtain the motion-dependent fluid-force coefficients are discussed and the general instability characteristics are summarized. The theory is also used to evaluate the results of other mathematical models for crossflow-induced instability. The fluid excitation forces acting on a tube array are presented as a function of Reynolds number, incoming flow conditions, and tube location in an array. The experimental data show the general characteristics of flow across a tube array. As the flow passes through each row of tubes, the fluid is subjected to resistance, the effect of which is to convert some of the fluid pressure energy to turbulent energy. In the first few rows, the transformation of energy occurs in a somewhat orderly manner. As the flow reaches the interior tubes, unsteadiness of the flow increases and, usually, a randomness of the flow and its pressure fluctuation exists in the flow field.

  9. Kinetic impairment of haemopoietic stem cells in experimentally induced leukemia and aplastic anemia: an inverse correlation.

    PubMed

    Chatterjee, Sumanta; Basak, Pratima; Das, Madhurima; Das, Prosun; Pereira, Jacintha Archana; Dutta, Ranjan Kumar; Chaklader, Malay; Chaudhuri, Samaresh; Law, Sujata

    2009-01-01

    The production of blood cells from bone marrow (BM) hematopoietic stem cells (HSC) is regulated by a number of cytokines and growth factors that influence cell survival; differentiation, proliferation and apoptosis in health and supposedly, such mechanisms are deregulated in diseased conditions. As far as cellular kinetics is concerned HSCs are relatively quiescent in adults, have the ability to replicate symmetrically and asymmetrically and predictably exhibit multi-lineage hematopoietic reconstitution potential. HSC drive hematopoiesis and homeostasis by contracting and expanding the pool of hematopoietic cells in the bone marrow. In mouse they can be identified immunophenotypically as Sca1+ c-kit cells. In aplastic anemia a drastic decline in the marrow efficacy to produce mature blood cells leads to bone marrow failure. In contrast, in leukemia hyper stimulated marrow leads to deregulated differentiation of immature hematopoietic stem cells with increased self-proliferation potential. In our experimental set up, we induced aplastic anemia by injecting busulfan and cyclophosphamide and leukemia by N-N' ethylnitrosourea intraperitoneally in inbred swiss albino mice. Indeed, HSCs and haematopoietic progenitor cells (HPCs) are vulnerable target for such disease oriented dysregulation which bears close correlation with the bone marrow microenvironmental damage. The present study aims at evaluating the possible mechanism(s) of deregulation in the bone marrow physiology with special reference to HSC surface receptor expression, cellular granularity, cell cycle status and overall marrow architecture. The investigations made so far revealed an interesting correlation between disease initiation and specific cytokinetic involvement of HSC in the BM microenvironment with particular reference to leukemia and aplastic anemia. PMID:20232602

  10. Experimental study of the Richtmyer-Meshkov instability induced by a Mach 3 shock wave

    SciTech Connect

    BP Puranik; JG Oakley; MH Anderson; R Bonaazza

    2003-11-12

    OAK-B135 An experimental investigation of a shock-induced interfacial instability (Richtmyer-Meshkov instability) is undertaken in an effort to study temporal evolution of interfacial perturbations in the late stages of development. The experiments are performed in a vertical shock tube with a square cross-section. A membraneless interface is prepared by retracting a sinusoidally shaped metal plate initially separating carbon dioxide from air, with both gases initially at atmospheric pressure. With carbon dioxide above the plate, the Rayleigh-Taylor instability commences as the plate is retracted and the amplitude of the initial sinusoidal perturbation imposed on the interface begins to grow. The interface is accelerated by a strong shock wave (M=3.08) while its shape is still sinusoidal and before the Kelvin-Helmhotz instability distorts it into the well known mushroom-like structures; its initial amplitude to wavelength ratio is large enough that the interface evolution enters its nonlinear stage very shortly after shock acceleration. The pre-shock evolution of the interface due to the Rayleigh-Taylor instability and the post-shock evolution of the interface due to the Richtmyer-Meshkov instability are visualized using planar Mie scattering. The pre-shock evolution of the interface is carried out in an independent set of experiments. The initial conditions for the Richtmyer-Meshkov experiment are determined from the pre-shock Rayleigh-Taylor growth. One image of the post-shock interface is obtained per experiment and image sequences, showing the post-shock evolution of the interface, are constructed from several experiments. The growth rate of the perturbation amplitude is measured and compared with two recent analytical models of the Richtmyer-Meshkov instability.

  11. Experimental study of vortex-induced vibrations of a tethered cylinder

    NASA Astrophysics Data System (ADS)

    Wang, X. K.; Su, B. Y.; Tan, S. K.

    2012-10-01

    This paper presents an experimental study of the motions, forces and flow patterns of a positively buoyant tethered cylinder (m*<1) in uniform flow undergoing vortex-induced vibration (VIV). The flow fields have been measured using digital Particle Image Velocimetry (PIV) technique, in conjunction with a piezoelectric load cell for direct measurement of drag and lift forces acting on the tethered cylinder. The effects of varying mass ratio and Reynolds number over the range 0.61≤m*≤0.92 and 4000≤Re≤12 000 are examined. Results of a fixed (or stationary) cylinder at the same Reynolds numbers are provided to serve as the benchmark reference. The peak amplitude of oscillation, θmax/θD, generally increases with Re and deceases with m*. Similar to previous studies, the results reveal the existence of a critical mass ratio mcrit*≈0.7, below which large-amplitude oscillations would take place when Re is high enough, with the largest peak amplitude of θmax/θD=0.9 observed for the case of m*=0.61 and Re=12 000. Thus two distinct states of oscillation are categorized, namely, the small- and large-amplitude oscillation states. The distinction between the two states is also vivid in the mean and root-mean-square (r.m.s.) force coefficients (including C, CD‧ and CL‧). The frequency of vortex shedding (fV) from the tethered cylinder is always synchronized with the cylinder's oscillation frequency (fosc), regardless of the oscillation state. A time series of instantaneous vorticity fields illustrate that vortex shedding from the tethered cylinder undergoing VIV maintains the 2S mode, but at an inclined angle to the free stream, which is most obvious in the large-amplitude oscillation state. This leads to an asymmetry in the shear layers separated from opposite sides of the cylinder, as shown by the distribution of ensemble-averaged Reynolds stress.

  12. Psychological and cortisol reactivity to experimentally induced stress in adults with ADHD.

    PubMed

    Raz, Sivan; Leykin, Dmitry

    2015-10-01

    Individuals with ADHD suffer from increased vulnerability to environmental and mental stressors and may be at increased risk for chronic stress in everyday life. The Hypothalamic-Pituitary-Adrenal (HPA) axis is a critical physiological system that mediates responses to stress. The present study seeks to examine test performance, test anxiety, self-reported psychological stress and cortisol reactivity to mental-cognitive stress in adults with ADHD when compared with healthy controls. Stress was induced by an arithmetic ability test. Psychological stress was assessed repeatedly throughout the experimental session. Salivary cortisol, an indicator of the HPA axis function, was evaluated immediately upon arrival, as well as 1 min and 20 min post-test completion. Results revealed higher levels of test anxiety and poorer performance on the test in the ADHD group. The ADHD and control groups showed no difference in base-line levels of subjective stress and in subjective stress levels 20 min after the test. In contrast, individuals with ADHD reported significantly higher levels of stress at the test anticipation phase and 1 min post-test completion. Cortisol response to stress differed according to group: in the ADHD group, 20 min post-test cortisol levels were significantly higher than base-line cortisol levels. This was not evident in the control group. These results suggest greater activation of the HPA axis in response to stress in adults with ADHD when compared with healthy controls. Adults with ADHD do not differ from controls in basal levels of subjective stress and cortisol, but do have stronger psychophysiological reactions in response to stressful challenges. The present findings are among the first to demonstrate significant alterations in cortisol reactivity to stress in adults with ADHD. PMID:26107579

  13. The effects of experimentally induced hyperthyroidism on the diving physiology of harbor seals (Phoca vitulina)

    PubMed Central

    Weingartner, Gundula M.; Thornton, Sheila J.; Andrews, Russel D.; Enstipp, Manfred R.; Barts, Agnieszka D.; Hochachka, Peter W.

    2012-01-01

    Many phocid seals are expert divers that remain submerged longer than expected based on estimates of oxygen storage and utilization. This discrepancy is most likely due to an overestimation of diving metabolic rate. During diving, a selective redistribution of blood flow occurs, which may result in reduced metabolism in the hypoperfused tissues and a possible decline in whole-body metabolism to below the resting level (hypometabolism). Thyroid hormones are crucial in regulation of energy metabolism in vertebrates and therefore their control might be an important part of achieving a hypometabolic state during diving. To investigate the effect of thyroid hormones on diving physiology of phocid seals, we measured oxygen consumption, heart rate, and post-dive lactate concentrations in five harbor seals (Phoca vitulina) conducting 5 min dives on command, in both euthyroid and experimentally induced hyperthyroid states. Oxygen consumption during diving was significantly reduced (by 25%) in both euthyroid and hyperthyroid states, confirming that metabolic rate during diving falls below resting levels. Hyperthyroidism increased oxygen consumption (by 7–8%) when resting in water and during diving, compared with the euthyroid state, illustrating the marked effect of thyroid hormones on metabolic rate. Consequently, post-dive lactate concentrations were significantly increased in the hyperthyroid state, suggesting that the greater oxygen consumption rates forced seals to make increased use of anaerobic metabolic pathways. During diving, hyperthyroid seals also exhibited a more profound decline in heart rate than seals in the euthyroid state, indicating that these seals were pushed toward their aerobic limit and required a more pronounced cardiovascular response. Our results demonstrate the powerful role of thyroid hormones in metabolic regulation and support the hypothesis that thyroid hormones play a role in modulating the at-sea metabolism of phocid seals. PMID:23060807

  14. Autophagy deficiency in myeloid cells increases susceptibility to obesity-induced diabetes and experimental colitis.

    PubMed

    Lee, Hae-Youn; Kim, Jinyoung; Quan, Wenying; Lee, June-Chul; Kim, Min-Soo; Kim, Seok-Hyung; Bae, Jin-Woo; Hur, Kyu Yeon; Lee, Myung-Shik

    2016-08-01

    Autophagy, which is critical for the proper turnover of organelles such as endoplasmic reticulum and mitochondria, affects diverse aspects of metabolism, and its dysregulation has been incriminated in various metabolic disorders. However, the role of autophagy of myeloid cells in adipose tissue inflammation and type 2 diabetes has not been addressed. We produced mice with myeloid cell-specific deletion of Atg7 (autophagy-related 7), an essential autophagy gene (Atg7 conditional knockout [cKO] mice). While Atg7 cKO mice were metabolically indistinguishable from control mice, they developed diabetes when bred to ob/w mice (Atg7 cKO-ob/ob mice), accompanied by increases in the crown-like structure, inflammatory cytokine expression and inflammasome activation in adipose tissue. Mφs (macrophages) from Atg7 cKO mice showed significantly higher interleukin 1 β release and inflammasome activation in response to a palmitic acid plus lipopolysaccharide combination. Moreover, a decrease in the NAD(+):NADH ratio and increase in intracellular ROS content after treatment with palmitic acid in combination with lipopolysaccharide were more pronounced in Mφs from Atg7 cKO mice, suggesting that mitochondrial dysfunction in autophagy-deficient Mφs leads to an increase in lipid-induced inflammasome and metabolic deterioration in Atg7 cKO-ob/ob mice. Atg7 cKO mice were more susceptible to experimental colitis, accompanied by increased colonic cytokine expression, T helper 1 skewing and systemic bacterial invasion. These results suggest that autophagy of Mφs is important for the control of inflammasome activation in response to metabolic or extrinsic stress, and autophagy deficiency in Mφs may contribute to the progression of metabolic syndrome associated with lipid injury and colitis. PMID:27337687

  15. A new modified animal model of myosin-induced experimental autoimmune myositis enhanced by defibrase

    PubMed Central

    Wen-Jing, Luo; Hong-Hua, Li; Xiang-Hui, Lu; Jie-Xiao, Liu

    2015-01-01

    Introduction We investigated the effect of defibrase (a proteolytic enzyme extraction of Agkistrodon halys venom) on experimental autoimmune myositis (EAM) in guinea pigs and explored the option of using a modified pig model of EAM to enhance the study of this disease. Material and methods Guinea pigs were divided into 3 groups: group A (control group) was immunized with complete Freund adjuvant (CFA), then received 6 injections of saline weekly; group B (EAM group) was immunized with partially purified rabbit myosin emulsified with CFA, then received an injection of saline; group C (EAM + defibrase group) was immunized with purified rabbit myosin emulsified with CFA, then received an injection of defibrase. The animals were observed for their general health condition and the body weight was measured daily. Plasma levels of fibrinogen and creatine kinase (CK) were determined. Muscle tissues were examined histologically. Results After immunizations for 6 weeks, incidence of EAM in groups A, B and C was 0 (0/7), 83.3% (10/12) and 100% (15/15), respectively. Guinea pigs with EAM presented angeitis symptoms of muscle weakness. Histological analysis revealed a significant difference. Muscles with EAM had scattered or diffuse inflammatory manifestations, which are also common pathological features of human idiopathic polymyositis (IPM). Defibrase-treated animals displayed extensive inflammation and fiber necrosis compared with the EAM group (histological score: 2.80 ±1.15 vs. 1.88 ±1.32, p < 0.05). Severity of inflammation of group B was mainly mild to moderate; 16.7% (2/12) of animals developed severe inflammation. Incidence of severe inflammation with a score up to 4 in group C was 40% (6/15). Conclusions Defibrase can exacerbate myosin-induced EAM; thus a new modified model was generated. PMID:26788090

  16. Temperature dependence of spectral induced polarization data: experimental results and membrane polarization theory

    NASA Astrophysics Data System (ADS)

    Bairlein, Katharina; Bücker, Matthias; Hördt, Andreas; Hinze, Björn

    2016-04-01

    Spectral induced polarization measurements are affected by temperature variations due to a variety of temperature-dependent parameters that control the complex electrical conductivity. Most important is the influence of the ion mobility, which increases with increasing temperature. It is responsible for the increase of the conductivity of the fluid in the pores with temperature and influences the electrical double layer on the mineral surface. This work is based on laboratory measurements of 13 sandstone samples from different sources with different geological and petrophysical characteristics. We measured the complex impedance in a frequency range from 0.01 to 100 Hz and a temperature range from 0 to 40 °C. The main observation is a decrease of the characteristic time (defined by the inverse of the frequency, at which the phase shift is maximum) with increasing temperature. The strength of this decrease differs from one sample to another. The temperature dependence of the phase shift magnitude cannot easily be generalized, as it depends on the particular sample. The experimental findings suggest that neglecting the influence of temperature on complex conductivity may lead to significant errors when estimating hydraulic conductivity from relaxation time. We also simulate the temperature dependence with a theoretical model of membrane polarization and review some of the model properties, with an emphasis on the temperature dependence of the parameters. The model reproduces several features characterizing the measured data, including the temperature dependence of the characteristic times. Computed tomography and microscope images of the pore structure of three samples also allow us to associate differences in the geometrical parameters used in the modelling with pore scale parameters of the actual samples.

  17. Experimental studies on lung carcinogenesis and their relationship to future research on radiation-induced lung cancer in humans

    SciTech Connect

    Cross, F.T.

    1991-03-01

    The usefulness of experimental systems for studying human lung carcinogenesis lies in the ease of studying components of a total problem. As an example, the main thrust of attack on possible synergistic interactions between radiation, cigarette smoke, and other irritants must be by means of research on animals. Because animals can be serially sacrificed, a systematic search can be made for progressive lung changes, thereby improving our understanding of carcinogenesis. The mechanisms of radiation-induced carcinogenesis have not yet been delineated, but modern concepts of molecular and cellular biology and of radiation dosimetry are being increasingly applied to both in vivo and in vitro exposure to determine the mechanisms of radiation-induced carcinogenesis, to elucidate human data, and to aid in extrapolating experimental animal data to human exposures. In addition, biologically based mathematical models of carcinogenesis are being developed to describe the nature of the events leading to malignancy; they are also an essential part of a rational approach to quantitative cancer risk assessment. This paper summarizes recent experimental and modeling data on radon-induced lung cancer and includes the confounding effects of cigarette-smoke exposures. The applicability of these data to understanding human exposures is emphasized, and areas of future research on human radiation-induced carcinogenesis are discussed. 7 refs., 2 figs., 3 tabs.

  18. Perspectives of patients, family caregivers and physicians about the use of opioids for refractory dyspnea in advanced chronic obstructive pulmonary disease

    PubMed Central

    Rocker, Graeme; Young, Joanne; Donahue, Margaret; Farquhar, Morag; Simpson, Catherine

    2012-01-01

    Background: A recent national practice guideline recommends the use of opioids for the treatment of refractory dyspnea in patients with advanced chronic obstructive pulmonary disease (COPD). We conducted two qualitative studies to explore the experiences of patients and family caregivers with opioids for refractory COPD-related dyspnea and the perspectives and attitudes of physicians toward opioids in this context. Methods: Patients (n = 8; 5 men, 3 women), their caregivers (n = 12; 5 men, 7 women) and physicians (n = 28, 17 men, 11 women) in Nova Scotia participated in the studies. Semistructured interviews were recorded, transcribed verbatim, coded conceptually and analyzed for emergent themes using interpretive description methodology. Results: Patients reported that opioids provided a sense of calm and relief from severe dyspnea. Family caregivers felt that opioids helped patients to breathe more “normally,” observed improvements in patients’ symptoms of anxiety and depression, and experienced reductions in their own stress. Patients reported substantial improvements in their quality of life. All patients and family caregivers wanted opioid therapy to continue. Most physicians were reluctant to prescribe opioids for refractory dyspnea, describing a lack of related knowledge and experience, and fears related to the potential adverse effects and legal censure. Interpretation: Discrepancies between the positive experiences of patients and family caregivers with opioids and the reluctance of physicians to prescribe opioids for refractory dyspnea constitute an important gap in care. Bridging this gap will require initiatives to improve the uptake of practice guidelines and to increase confidence in prescribing opioids for dyspnea refractory to conventional treatment. PMID:22529167

  19. Minocycline attenuates experimental colitis in mice by blocking expression of inducible nitric oxide synthase and matrix metalloproteinases

    SciTech Connect

    Huang, T.-Y.; Chu, H.-C.; Lin, Y.-L.; Lin, C.-K.; Hsieh, T.-Y.; Chang, W.-K.; Chao, Y.-C.; Liao, C.-L.

    2009-05-15

    In addition to its antimicrobial activity, minocycline exerts anti-inflammatory effects in several disease models. However, whether minocycline affects the pathogenesis of inflammatory bowel disease has not been determined. We investigated the effects of minocycline on experimental colitis and its underlying mechanisms. Acute and chronic colitis were induced in mice by treatment with dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS), and the effect of minocycline on colonic injury was assessed clinically and histologically. Prophylactic and therapeutic treatment of mice with minocycline significantly diminished mortality rate and attenuated the severity of DSS-induced acute colitis. Mechanistically, minocycline administration suppressed inducible nitric oxide synthase (iNOS) expression and nitrotyrosine production, inhibited proinflammatory cytokine expression, repressed the elevated mRNA expression of matrix metalloproteinases (MMPs) 2, 3, 9, and 13, diminished the apoptotic index in colonic tissues, and inhibited nitric oxide production in the serum of mice with DSS-induced acute colitis. In DSS-induced chronic colitis, minocycline treatment also reduced body weight loss, improved colonic histology, and blocked expression of iNOS, proinflammatory cytokines, and MMPs from colonic tissues. Similarly, minocycline could ameliorate the severity of TNBS-induced acute colitis in mice by decreasing mortality rate and inhibiting proinflammatory cytokine expression in colonic tissues. These results demonstrate that minocycline protects mice against DSS- and TNBS-induced colitis, probably via inhibition of iNOS and MMP expression in intestinal tissues. Therefore, minocycline is a potential remedy for human inflammatory bowel diseases.

  20. Silymarin ameliorates memory deficits and neuropathological changes in mouse model of high-fat-diet-induced experimental dementia.

    PubMed

    Neha; Kumar, Amit; Jaggi, Amteshwar S; Sodhi, Rupinder K; Singh, Nirmal

    2014-08-01

    A huge body evidences suggest that obesity is the single great risk factor for the development of dementia. Recently, silymarin, a flavonoid, clinically in use as a hepatoprotectant, has been reported to prevent amyloid beta-induced memory impairment by reducing oxidative stress and inflammation in mice brain. However, its potential in high-fat-diet (HFD)-induced dementia has not yet been investigated. Therefore, the present study is designed to explore the role of silymarin in HFD-induced experimental dementia in mice. Morris water maze test was employed to assess learning and memory. Various biochemical estimations including brain acetylcholinerstarse activity (AchE), thiobarbituric acid-reactive species (TBARS) level, reduced glutathione level (GSH), nirate/nitrite, and myeloperoxidase (MPO) activity were measured. Serum cholesterol level was also determined. HFD significantly impaired the cognitive abilities, along with increasing brain AchE, TBARS, MPO, nitrate/nitrite, and serum cholesterol levels. Marked reduction of brain GSH levels was observed. On the contrary, silymarin significantly reversed HFD-induced cognitive deficits and the biochemical changes. The present study indicates strong potential of silymarin in HFD-induced experimental dementia. PMID:24866499

  1. Experimental Assessment and Enhancement of Planar Laser-Induced Fluorescence Measurements of Nitric Oxide in an Inverse Diffusion Flame

    NASA Technical Reports Server (NTRS)

    Partridge, William P.; Laurendeau, Normand M.

    1997-01-01

    We have experimentally assessed the quantitative nature of planar laser-induced fluorescence (PLIF) measurements of NO concentration in a unique atmospheric pressure, laminar, axial inverse diffusion flame (IDF). The PLIF measurements were assessed relative to a two-dimensional array of separate laser saturated fluorescence (LSF) measurements. We demonstrated and evaluated several experimentally-based procedures for enhancing the quantitative nature of PLIF concentration images. Because these experimentally-based PLIF correction schemes require only the ability to make PLIF and LSF measurements, they produce a more broadly applicable PLIF diagnostic compared to numerically-based correction schemes. We experimentally assessed the influence of interferences on both narrow-band and broad-band fluorescence measurements at atmospheric and high pressures. Optimum excitation and detection schemes were determined for the LSF and PLIF measurements. Single-input and multiple-input, experimentally-based PLIF enhancement procedures were developed for application in test environments with both negligible and significant quench-dependent error gradients. Each experimentally-based procedure provides an enhancement of approximately 50% in the quantitative nature of the PLIF measurements, and results in concentration images nominally as quantitative as LSF point measurements. These correction procedures can be applied to other species, including radicals, for which no experimental data are available from which to implement numerically-based PLIF enhancement procedures.

  2. Arsenic-induced phosphate limitation under experimental Early Proterozoic oceanic conditions

    NASA Astrophysics Data System (ADS)

    Chi Fru, Ernest; Hemmingsson, Christoffer; Holm, Mikaela; Chiu, Beverly; Iñiguez, Enrique

    2016-01-01

    Comparison of phosphorus concentrations associated with modern hydrothermal Fe(III)(oxyhydr)oxides and ancient Fe(III) oxide-rich iron formations, is used to estimate bioavailable Precambrian marine phosphorus (P) concentrations. This led to the proposition of a low dissolved P budget of ˜10-25% of present-day levels, before ˜1.9 billion years ago. Estimates incorporating ancient marine Si levels ≥ 0.67 mM instead suggested global dissolved P levels greater than today. Here we unite current experimental models that have considered NaCl solutions containing elevated dissolved Fe(II), Si, Ca2+ and Mg2+ ions in the incorporation of P in Precambrian marine Fe(III)(oxyhydr)oxides, in addition to arsenic as a hydrothermal proxy. We show that the coprecipitation of dissolved P and Fe(III)(oxyhydr)oxides from arsenic-rich marine waters produces an average P distribution coefficient of ˜0.072 (± 0.01) μM-1. This is comparable to the ˜ 0.07 μM-1 predicted for Fe(III)(oxyhydr)oxides in modern arsenic-rich, submarine hydrothermal settings, from which the lower Early Proterozoic dissolved marine P concentrations were predicted. As/P molar ratios below modern seawater ratios removed the negative feedback effect high Si impose on P scavenging by Fe(III)(oxyhydr)oxides. The binding of As(III) to Fe(III)(oxyhydr)oxides exhibits a lower competitive influence on P fixation. As(V) that likely became prominent in the surficially oxidized Early Proterozoic oceans induced dissolved P limitation because of preferential P sequestration at the expense of dissolved As(V) enrichment. The control of As on P scavenging by the precipitating Fe(III)(oxyhydr)oxides is strong regardless of common seawater cations (Mg2+ and Ca2+). The data suggest that the application of Si and Fe(III)(oxyhydr)oxides as an ancient seawater P proxy should consider chemical variability between depositional basins, taking into account the rather strong role hydrothermal arsenic has on the distribution of P in

  3. Experimental study of blast-induced traumatic brain injury using a physical head model.

    PubMed

    Zhang, Jiangyue; Pintar, Frank A; Yoganandan, Narayan; Gennarelli, Thomas A; Son, Steven F

    2009-11-01

    This study was conducted to quantify intracranial biomechanical responses and external blast overpressures using physical head model to understand the biomechanics of blast traumatic brain injury and to provide experimental data for computer simulation of blast-induced brain trauma. Ellipsoidal-shaped physical head models, made from 3-mm polycarbonate shell filled with Sylgard 527 silicon gel, were used. Six blast tests were conducted in frontal, side, and 45 degrees oblique orientations. External blast overpressures and internal pressures were quantified with ballistic pressure sensors. Blast overpressures, ranging from 129.5 kPa to 769.3 kPa, were generated using a rigid cannon and 1.3 to 3.0 grams of pentaerythritol tetranitrate (PETN) plastic sheet explosive (explosive yield of 13.24 kJ and TNT equivalent mass of 2.87 grams for 3 grams of material). The PETN plastic sheet explosive consisted of 63% PETN powder, 29% plasticizer, and 8% nitrocellulose with a density of 1.48 g/cm3 and detonation velocity of 6.8 km/s. Propagation and reflection of the shockwave was captured using a shadowgraph technique. Shockwave speeds ranging from 423.3 m/s to 680.3 m/s were recorded. The model demonstrated a two-stage response: a pressure dominant (overpressure) stage followed by kinematic dominant (blast wind) stage. Positive pressures in the brain simulant ranged from 75.1 kPa to 1095 kPa, and negative pressures ranged from -43.6 kPa to -646.0 kPa. High- and normal-speed videos did not reveal observable deformations in the brain simulant from the neutral density markers embedded in the midsagittal plane of the head model. Amplitudes of the internal positive and negative pressures were found to linearly correlate with external overpressure. Results from the current study suggested a pressure-dominant brain injury mechanism instead of strain injury mechanism under the blast severity of the current study. These quantitative results also served as the validation and calibration

  4. Experimental investigation of the wave-induced flow around a surface-touching cylinder

    NASA Astrophysics Data System (ADS)

    Mattioli, M.; Mancinelli, A.; Brocchini, M.

    2013-02-01

    The wave-induced flow around a circular cylinder near both a rigid wall and an erodible bed is experimentally investigated using Particle Tracking Velocimetry (PTV). The aim of this study is to gain quantitative information on the local mean flow, the vorticity dynamics and the evolution of the erodible bed. The flow is characterized in terms of the Keulegan-Carpenter (KC), Reynolds (Re) and Ursell (Ur) numbers. The effects of changing these parameters over the ranges 1

  5. Adrenomedullin protects from experimental arthritis by down-regulating inflammation and Th1 response and inducing regulatory T cells.

    PubMed

    Gonzalez-Rey, Elena; Chorny, Alejo; O'Valle, Francisco; Delgado, Mario

    2007-01-01

    Rheumatoid arthritis is a chronic autoimmune disease of unknown etiology characterized by chronic inflammation in the joints and subsequent destruction of the cartilage and bone. The present study proposes a new strategy for the treatment of arthritis: the administration of the immunomodulatory neuropeptide adrenomedullin. Treatment with adrenomedullin significantly reduced incidence and severity of collagen-induced arthritis, an experimental model of rheumatoid arthritis, completely abrogating joint swelling and destruction of cartilage and bone. The therapeutic effect of adrenomedullin was associated with a striking reduction of the two deleterious components of the disease, ie, the Th1-driven autoimmune and inflammatory responses. Adrenomedullin also induced the generation and/or activation of efficient CD4+ CD25+ regulatory T cells in arthritis with capacity to suppress autoreactive response and restore immune tolerance, which could play a pivotal role in the therapeutic effect of adrenomedullin on experimental arthritis contributing to the restoration of immune tolerance. PMID:17200199

  6. Sudden severe postoperative dyspnea following shoulder surgery: Remember inadvertent phrenic nerve block due to interscalene brachial plexus block.

    PubMed

    Jariwala, Arpit; Kumar, B C Raju Pavan; Coventry, David M

    2014-04-01

    Advanced imaging techniques, improved operative techniques, and instrumentation combined with better patient awareness and expectations have resulted in an exponential increase in upper limb surgical procedures during recent times. Surgical teams expect superior analgesia and regional blocks have matched these expectations quite often resulting in improved patient satisfaction and early rehabilitation to achieve best results. Ultrasound-guided interscalene brachial plexus block (ISB) is commonly used to provide analgesia for procedures involving shoulder girdle. We report a case of symptomatic hemi-diaphragmatic paresis (HDP) due to the phrenic nerve block following ISB for arthroscopic sub-acromial decompression of the shoulder presenting as severe postoperative dyspnea. There is strong evidence of HDP following ISB in anesthetic literature, but not reported in related surgical specialties such as orthopedics. We wish to inform upper-limb surgeons and educate junior doctors and other ancillary staff working in upper-limb units to be aware of this serious but reversible complication. PMID:25114416

  7. The Relationship Among Evidence-Based Practice and Client Dyspnea, Pain, Falls, and Pressure Ulcer Outcomes in the Community Setting

    PubMed Central

    Doran, Diane; Lefebre, Nancy; O'Brien-Pallas, Linda; Estabrook, Carole A; White, Peggy; Carryer, Jennifer; Sun, Winnie; Qian, Gan; Bai, Yu Qing (Chris); Li, Mingyang

    2014-01-01

    Background There are gaps in knowledge about the extent to which home care nurses’ practice is based on best evidence and whether evidence-based practice impacts patient outcomes. Aim The purpose of this study was to investigate the relationship between evidence-based practice and client pain, dyspnea, falls, and pressure ulcer outcomes in the home care setting. Evidence-based practice was defined as nursing interventions based on best practice guidelines. Methods The Nursing Role Effectiveness model was used to guide the selection of variables for investigation. Data were collected from administrative records on percent of visits made by Registered Nurses (RN), total number of nursing visits, and consistency of visits by principal nurse. Charts audits were used to collect data on nursing interventions and client outcomes. The sample consisted of 338 nurses from 13 home care offices and 939 de-identified client charts. Hierarchical generalized linear regression approaches were constructed to explore which variables explain variation in client outcomes. Results The study found documentation of nursing interventions based on best practice guidelines was positively associated with improvement in dyspnea, pain, falls, and pressure ulcer outcomes. Percent of visits made by an RN and consistency of visits by a principal nurse were not found to be associated with improved client outcomes, but the total number of nursing visits was. Linking Evidence to Action Implementation of best practice is associated with improved client outcomes in the home care setting. Future research needs to explore ways to more effectively foster the documentation of evidence-based practice interventions. PMID:25099877

  8. Experimental investigation of effects of jet decay rate on jet-induced pressures on a flat plate: Tabulated data

    NASA Technical Reports Server (NTRS)

    Kuhlman, J. M.; Ousterhout, D. S.; Warcup, R. W.

    1978-01-01

    Tabular data are presented for an experimental study of the effects of jet decay rate on the jet-induced pressure distribution on a flat plate for a single jet issuing at right angle to the flat plate into a uniform crossflow. The data are presented in four sections: (1) presents the static nozzle calibration data; (2) lists the plate surface static pressure data and integrated loads; (3) lists the jet centerline trajectory data; and (4) lists the centerline dynamic pressure data.

  9. Experimental Study Of Metallurgical Evolutions In Metallic Alloys Induced By Laser Generated High Pressure Shocks

    NASA Astrophysics Data System (ADS)

    Fabbro, R.; Fournier, J.; Fabre, E.; Leberichel, E.; Hannau, Th; Corbet, C.

    1986-11-01

    Some preliminary results are presented concerning the damages and the evolutions of metallurgical properties of Fe-C alloys induced by laser shock waves at two different laser wavelengths. In the present work, changes induced by laser shocking have been measured : pressure, microhardness, residual stresses. In addition microstructural variations at the surface and in depth have been observed.

  10. Evaluation of safety and protective effects of Potentilla fulgens root extract in experimentally induced diarrhea in mice

    PubMed Central

    Tangpu, Vareishang; Deori, Khirod; Yadav, Arun Kumar

    2014-01-01

    Aim: The roots of Potentilla fulgens Wall. ex Hook. (Rosaceae) have been used in the indigenous system of medicine in Northeast India to treat diarrhea. The aim of this study was to investigate the safety and protective effects of P. fulgens root extract in experimentally induced diarrhea in mice. Materials and Methods: The protective effects of P. fulgens root extract was investigated against experimentally induced diarrhea in mice, using four experimental models, that is the measurement of fecal output, castor oil model, prostaglandin E2 (PGE2) enteropooling assay, and gastrointestinal transit test. The safety assessment of root extract was done in mice on the basis of general signs and symptoms of toxicity, food water intake and mortality of animals following their treatment with various doses of extract (100-3200 mg/kg). In addition, the serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, cholesterol and total protein of experimental mice were also monitored to assess the toxicity of root extract. Results: In the safety assessment studies, P. fulgens root extract did not showed any visible signs of toxicity, but mortality was observed in a single animal at 3200 mg/kg dose of extract. The extract also did not showed any adverse effects on the studied serum parameters of experimental animals. In the antidiarrheal tests, administration of 800 mg/kg dose of extract to mice showed 50% protection from diarrhea evoked by castor oil. In addition, the extract also showed 29.27% reduction in PGE2-induced intestinal secretion as compared with 30.31% recorded for loperamide, a standard antidiarrheal drug. Conclusions: The results of this study indicate that P. fulgens root extract possesses significant antidiarrheal properties. Therefore, the roots of this plant can be an effective traditional medicine for protection from diarrhea. PMID:26401356

  11. Hypoxia-inducible factor-1alpha expression in experimental cirrhosis: correlation with vascular endothelial growth factor expression and angiogenesis.

    PubMed

    Bozova, Sevgi; Elpek, Gülsüm Ozlem

    2007-07-01

    Angiogenesis progresses together with fibrogenesis during chronic liver injury. Hypoxia-inducible factor-1alpha (HIF-1alpha), a master regulator of homeostasis, plays a pivotal role in hypoxia-induced angiogenesis through its regulation of vascular endothelial growth factor (VEGF). The association between hypoxia, angiogenesis and VEGF expression has been demonstrated in experimental cirrhosis. However, expression of HIF-1alpha has yet to be reported. The aim of this study was to investigate the significance of HIF-1alpha expression during experimental liver fibrosis and the relationships between HIF-1alpha expression, VEGF expression and angiogenesis. Cirrhosis was induced in male Wistar rats by intraperitoneal administration of diethyl nitrosamine (DEN) (100 mg/kg, once a week). The serial sections from liver tissues were stained with anti-HIF-1alpha, anti-VEGF and anti-CD34 antibodies before being measured by light microscopy. Our results showed that HIF-1alpha expression gradually increases according to the severity of fibrosis (p<0.01). Moreover, its expression was found to be correlated with angiogenesis (r=0.916) and VEGF expression (r=0.969). The present study demonstrates that HIF-1alpha might have a role in the development of angiogenesis via regulation of VEGF during experimental liver fibrogenesis and suggests that this factor could be a potential target in the manipulation of angiogenesis in chronic inflammatory diseases of the liver. PMID:17614845

  12. Kaempferol-human serum albumin interaction: Characterization of the induced chirality upon binding by experimental circular dichroism and TDDFT calculations

    NASA Astrophysics Data System (ADS)

    Matei, Iulia; Ionescu, Sorana; Hillebrand, Mihaela

    2012-10-01

    The experimental induced circular dichroism (ICD) and absorption spectra of the achiral flavonoid kaempferol upon binding to human serum albumin (HSA) were correlated to electronic CD and UV-vis spectra theoretically predicted by time-dependent density functional theory (TDDFT). The neutral and four anionic species of kaempferol in various conformations were considered in the calculations. The appearance of the experimental ICD signal was rationalized in terms of kaempferol binding to HSA in a distorted, chiral, rigid conformation. The comparison between the experimental and simulated spectra allowed for the identification of the kaempferol species that binds to HSA, namely the anion generated by deprotonation of the hydroxyl group in position 7. This approach constitutes a convenient method for evidencing the binding species and for determining its conformation in the binding pocket of the protein. Its main advantage over the UV-vis absorption method lays in the fact that only the bound ligand species gives an ICD signal.

  13. Numerical and experimental study on flow-induced noise at blade-passing frequency in centrifugal pumps

    NASA Astrophysics Data System (ADS)

    Yang, Jun; Yuan, Shouqi; Yuan, Jianping; Si, Qiaorui; Pei, Ji

    2014-05-01

    With the increasing noise pollution, low noise optimization of centrifugal pimps has become a hot topic. However, experimental study on this problem is unacceptable for industrial applications due to unsustainable cost. A hybrid method that couples computational fluid dynamics (CFD) with computational aeroacoustic software is used to predict the flow-induced noise of pumps in order to minimize the noise of centrifugal pumps in actual projects. Under Langthjem's assumption that the blade surface pressure is the main flow-induced acoustic source in centrifugal pumps, the blade surface pressure pulsation is considered in terms of the acoustical sources and simulated using CFX software. The pressure pulsation and noise distribution in the near-cutoff region are examined for the blade-passing frequency (BPF) noise, and the sound pressure level (SPL) reached peaks near the cutoff that corresponded with the pressure pulsation in this region. An experiment is performed to validate this prediction. Four hydrophones are fixed to the inlet and outlet ports of the test pump to measure the flow-induced noise from the four-port model. The simulation results for the noise are analyzed and compared with the experimental results. The variation in the calculated noise with changes in the flow agreed well with the experimental results. When the flow rate was increased, the SPL first decreased and reached the minimum near the best efficient point (BEP); it then increased when the flow rate was further increased. The numerical and experimental results confirmed that the BPF noise generated by a blade-rotating dipole roughly reflects the acoustic features of centrifugal pumps. The noise simulation method in current study has a good feasibility and suitability, which could be adopted in engineering design to predict and optimize the hydroacoustic behavior of centrifugal pumps.

  14. Root extract of Anacyclus pyrethrum ameliorates seizures, seizure-induced oxidative stress and cognitive impairment in experimental animals.

    PubMed

    Pahuja, Monika; Mehla, Jogender; Reeta, K H; Joshi, Sujata; Gupta, Yogendra Kumar

    2012-02-01

    In Ayurveda, Anacyclus pyrethrum has been used as a brain tonic. The present study evaluates the effect of hydroalcoholic extract of A. pyrethrum (HEAP) root against seizures, seizure-induced oxidative stress and cognitive impairment in experimental models of seizures. Male Wistar rats were used in the study. HEAP was administered in doses of 50, 100, 250, 500 in pentylenetetrazole (PTZ) model and 250, 500 and 1000 mg/kg in maximal electroshock (MES) model. Myoclonic jerk latency and generalized tonic clonic seizures (GTCS) were noted in PTZ whereas occurrence of tonic hind limb extension (THLE) was observed in MES seizures. Cognitive deficit was assessed using elevated plus maze and passive avoidance tests. Whole brain reduced glutathione, malondialdehyde levels and cholinesterase activity were measured. HEAP showed 50, 66.7, 83.3 and 100% protection at 50,100, 250 and 500 mg/kg, respectively against GTCS in PTZ induced seizures. In MES induced seizures, HEAP produced 16.7, 33.3 and 50% protection against THLE at 250, 500 and 1000 mg/kg, respectively. HEAP administration significantly prevented seizure induced oxidative stress and cognitive impairment in a dose-dependent manner. HEAP also normalized the decrease in cholinesterase activity caused by seizures. Thus, HEAP showed protective effect against seizures, seizure-induced oxidative stress and cognitive impairment in rats. PMID:21993359

  15. Therapeutic effect of D-002 (abexol) on gastric ulcer induced experimentally in rats.

    PubMed

    Molina, Vivian; Carbajal, Daisy; Arruzazabala, Lourdes; Más, Rosa

    2005-01-01

    D-002 is a mixture of higher aliphatic primary alcohols isolated from beeswax, wherein triacontanol is the most abundant alcohol, with antioxidant and anti-ulcer properties. Since compounds with cytoprotective and antioxidant effects can improve healing of gastroduodenal ulcer induced by noxious agents, this work investigated the healing effect of D- 002 on acute and chronic gastric ulcers induced with indomethacin and acetic acid, respectively, in rats. Acute gastric ulcer was induced with single oral doses of indomethacin (20 mg/kg). Treatments with D-002 at 50, 100, and 200 mg/kg or vehicle were administered 3 hours after ulcer induction. Three hours later, rats were sacrificed, and the stomach was removed for quantifying the lesions. Chronic gastric ulcer was induced by 50 microL of 80% acetic acid application on the anterior serosal surface of the glandular stomach during 20 seconds. Twenty-four hours later D-002 at 50, 100, and 200 mg/kg or vehicle was administered for 5 days. At the end of the treatment, animals were fasted for 24 hours and sacrificed, the stomachs were removed, and the lesions were quantified. D-002 orally administered at 100 and 200 mg/kg acutely significantly healed gastric ulcers induced with indomethacin by 39% and 56% compared with positive controls, respectively. Also, D-002 at 200 mg/kg, but not at 50 or 100 mg/kg, administered orally for 5 days after ulcer induction exerted a significant healing effect (65.8% inhibition) in gastric ulcers induced with acetic acid. In conclusion, this work demonstrated that D-002 administered after ulcer induction induced effective healing of acute and chronic gastric ulcers provoked by, respectively, indomethacin and acetic acid. PMID:15857211

  16. Effect of the Angiotensin I Converting Enzyme Inhibitor, MK-421, on Experimentally Induced Drinking

    NASA Technical Reports Server (NTRS)

    Fregley, Melvin J.; Fater, Dennis C.; Greenleaf, John E.

    1982-01-01

    MK-421, the ethyl ester maleate salt of N-(S)-1-(ethoxycarbonyl)-3-phenyl-propyl- Ala-L-Pro, is an angiotensin I converting enzyme inhibitor. An initial objective was to determine whether MK-421, administered at 0, 2.5, 5.0, 10.0, 20.0 and 40.0 mg/kg, ip to 96 female rats 15 min prior to administration of the beta-adrenergic agonist, isoproterenol (25 microgram/kg, ip), would inhibit the drinking induced by isoproterenol during 2 h after its administration. The water intake induced by isoproterenol was inhibited significantly by 2.5 mg MK-421/kg. When a similar experiment was performed using Angiotensin I (AI) (200 microgram/kg, ip) as the dipsogenic agent, MK-421 (5 mg/kg, ip), administered 15 min prior to AI, inhibited significantly both the dipsogenic and the diuretic effect of AI. However, administration of angiotensin II (AII, 200 microgram/kg, ip) 15 min after MK-421 (5mg/kg) was accompanied by a water intake that did not differ from AII alone. The drink induced by ip administration of 1.0 m NaCl solution (1% of body wt, ip) was not inhibited by administration of MK-421 (5 mg/kg) 15 min prior to allowing access to water while the drink induced by a 24 h dehydration was partially inhibited. Thus, the drinks induced by administraition of either isoproterenol or AI are dependent on formation of AII. That induced by dehydration is partially dependent, while that induced by hypertonic siilinc is independent of the formation of AII.

  17. Mechanisms of T-lymphocyte accumulation during experimental pleural infection induced by Mycobacterium bovis BCG.

    PubMed

    Souza, Mariana C; Penido, Carmen; Costa, Maria F S; Henriques, Maria Graças

    2008-12-01

    Tuberculous pleurisy is a frequent extrapulmonary manifestation characterized by accumulation of fluid and inflammatory cells in the pleural space. Here, we investigated the mechanisms of T-lymphocyte accumulation in the pleural space by using a murine model of pleurisy induced by Mycobacterium bovis BCG. Intrathoracic (i.t.) injection of BCG (4.5 x 10(5) bacteria/cavity) induced accumulation of T lymphocytes in the pleural cavities of C57BL/6 mice. We observed the presence of CFU in pleural washes conducted 1, 2, 3, 7, and 15 days after pleurisy induction. Pretreatment with fucoidan inhibited T-lymphocyte accumulation at 1 day, but not at 15 days, after BCG-induced pleurisy. Accordingly, adoptive transfer of fluorescein isothiocyanate-labeled blood mononuclear cells to infected mice showed that T lymphocytes migrated into the pleural cavity 1 day (but not 15 days) after BCG injection. Cell-free pleural wash fluids recovered from mice 1 day after BCG i.t. stimulation (day 1 BCG-PW), but not day 7 or day 15 BCG-PW, induced in vitro T-cell transmigration, which was dependent on L-, P-, and E-selectins. In contrast, day 7 BCG-PW (but not day 1 BCG-PW) induced in vitro T-lymphocyte proliferation via interleukin-2 (IL-2) and gamma interferon (IFN-gamma). Accordingly, in vivo IL-2 or IFN-gamma neutralization abolished T-lymphocyte accumulation 7 days after pleurisy induction. Our results demonstrate that pleural infection induced by BCG leads to T-lymphocyte accumulation in two waves. The acute phase depends on selectin-mediated migration, while the second wave of T-lymphocyte accumulation seems to depend on a local proliferation induced by cytokines produced in situ. PMID:18809659

  18. Nicorandil inhibits neutrophil recruitment in carrageenan-induced experimental pleurisy in mice.

    PubMed

    Matsui, Tamires C; Coura, Giovanna M E; Melo, Ivo S F; Batista, Carla R A; Augusto, Paulo Sérgio A; Godin, Adriana M; Araújo, Débora P; César, Isabela C; Ribeiro, Lucas S; Souza, Danielle G; Klein, André; de Fátima, Ângelo; Machado, Renes R; Coelho, Márcio M

    2015-12-15

    Nicorandil is a drug characterized by the coupling of a nitric oxide (NO) donor to nicotinamide. We have previously demonstrated that nicotinamide exhibits activity in different models of pain and inflammation. Now, we investigated the effects induced by per os (p.o.) administration of nicorandil (25, 50 or 100mg/Kg) on neutrophil recruitment in a carrageenan-induced model of pleurisy in mice. Effects induced by nicorandil (100mg/kg) were compared with those induced by equimolar doses of nicotinamide (58mg/kg) and N-(2-hydroxyethyl)-nicotinamide (NHN; 79mg/kg). We also investigated whether effects on the production of inflammatory mediators play a role in the activity of nicorandil. P.o. nicorandil, 0.5h before and 1h after the i.pl. injection of carrageenan, reduced neutrophil recruitment. However, equimolar doses of nicotinamide or NHN failed to induce such effect. Single treatment (previous or late) with nicorandil (100mg/Kg, p.o.) also reduced neutrophils recruitment, although to a lesser extent when compared to the double treatment. Nicorandil reduced the concentrations of interleukin-1β, CXCL-1 and prostaglandin E2 in the pleural exudate. Concluding, we demonstrated the activity of nicorandil in a model of pleurisy induced by carrageenan. This activity was characterized by reduction of the neutrophil accumulation and inhibition of production of inflammatory mediators. The effects induced by nicorandil on the leukocytes recruitment and production of inflammatory mediators contribute to a better understanding of its clinical benefits and indicate that these benefits may be due to its vasodilating and anti-inflammatory activities. PMID:26607465

  19. Nondestructive prediction of point source pyroshock response spectra based on experimental conditioning of laser-induced shocks

    NASA Astrophysics Data System (ADS)

    Jang, Jae-Kyeong; Lee, Jung-Ryul

    2014-09-01

    Pyroshock can easily cause failures in electronic and optical components that are sensitive to high-frequency energy. Pyroshock is generated during explosive-based pyrotechnical events, such as the separation of boosters from a space shuttle and the separation of satellites from a space launcher. Therefore, the prediction of high-frequency structural response, particularly the shock response spectrum (SRS), is important for safe operation of pyrotechnical devices. In general, real explosive testing using distributed accelerometers is widely used. This paper proposes a technology to replace the expensive, dangerous, low-repeatability explosive test with a laser-induced shock test based on a laser beam and in-line filter conditioning. This method does not use any special numerical signal processing. Two different experiments based on explosive and laser excitation were performed with a 2-mm thick aluminum plate. The optimum laser-induced shock experimental conditions to predict real pyroshock were investigated while considering the size, energy, and fluence of the laser beam as parameters. The similarity of the SRS of the laser-induced shock to that of the real explosive pyroshock was evaluated based on the mean acceleration difference (MAD, %). The experimentally determined optimal conditions were also applied to four points on the path of a pyroshock propagation. To match the SRS at each point, the laser-induced shock was amplified, for which three different gain concepts are proposed: the initial gain, optimized gain, and constant gain. The proposed technology enables nondestructive pyro SRS prediction by conditioning the laser-induced shock to obtain an SRS with high similarity to the real pyroshock.

  20. TR PIV Experimental Investigation on Bypass Transition Induced by a Cylinder Wake

    NASA Astrophysics Data System (ADS)

    Tang, Zhan-Qi; Jiang, Nan

    2011-05-01

    The process of laminar to turbulent transition induced by a cylinder wake is studied by time-resolved (TR) particle image velocimetry (PIV) in a water channel. The combination of multi-scale local-averaged structure function analysis with criteria is used to identify the generation of secondary transverse vortex structure and to track its evolution along the streamwise. At the beginning of transition, with the decent of cylinder wake vortex, the secondary vortex structure is induced near the wall. As the secondary vortex moves downstream, it is induced to lift up by the wake vortex, meanwhile they are diffused and dissipated. According to the method of spatial conditional average, a low-speed hump is found in the near-wall region along the bypass transition zone, accompanied by a low-speed region in the free stream occupied by the wake vortex. With further downstream, the hump in the near-wall region becomes more and more obvious. At the later stage of transition zone, hairpin vortex can be seen by conditional-averaged low-pass filtered vorticity. The hairpin head is almost vertical to the wall with an inclination angle of about 90°, which is attributed to the additional lift-up behavior induced by wake vortex. It can be concluded that in the process of bypass transition, the wake vortex would not only induce the secondary vortex but also leaven its growth and evolution, resulting in the robust and rapidly growing hairpin vortex.

  1. Protective action of vinpocetine against experimentally induced gastric damage in rats.

    PubMed

    Nosálová, V; Machová, J; Babulová, A

    1993-09-01

    The efficacy of vinpocetine (CAS 42971-09-5) to prevent gastric mucosal damage induced by several noxious agents and its antisecretory effect were studied in rats. Vinpocetine administered orally or intraperitoneally inhibited the development of gastric lesions induced by 96% ethanol in a dose-dependent way. The highest protective activity was observed when vinpocetine was given intraperitoneally 30 min before ethanol, and its effect was still significant when administered 120 min before ethanol exposure. Oral administration of vincamine also displayed gastroprotective action in this model. Pretreatment with indometacin counteracted the protective action of vinpocetine against ethanol-induced damage, suggesting the involvement of a prostaglandin-mediated mechanism. The protective effect of vinpocetine was compared with that of prostaglandin E2, sucralfate, and tripotassium dicitrate bismuthate. The antiulcer activity of vinpocetine was demonstrated also in gastric injury induced by phenylbulazone and in chronic gastric ulcer induced by acetic acid. Histamine-stimulated gastric acid secretion in pylorus-ligated rats was partially inhibited by vinpocetine administered intraduodenally. The activity of vinpocetine established in these experiments is indicative of its potential clinical value as a gastroprotective agent. PMID:8240463

  2. Hyperactivity induced by prenatal BrdU exposure across several experimental conditions.

    PubMed

    Kuwagata, Makiko; Ogawa, Tetsuo; Muneoka, Katsumasa; Shioda, Seiji

    2011-12-01

    Behavioral results are sometimes not reproducible even in the positive controls of developmental neurotoxicity (DNT) tests. Effects of several factors on the results should be considered. In the present paper, we examined the effects of strain-, gender-, and test-condition differences on BrdU-induced hyperactivity. The results showed that BrdU-induced hyperactivity was reproducible in two rat strains (SD and F344 rats), rodent species (rat and mouse), and both sexes. When the level of background sound in a test room was increased, the hyperactivity was persistent, resulting in no effect of background sound on BrdU-induced hyperactivity. Thus, we have demonstrated that the BrdU-animal model is a useful positive control via prenatal exposure to validate the entire DNT test process. PMID:22103457

  3. Basal ganglia calcification induced by excitotoxicity: an experimental model characterised by electron microscopy and X-ray microanalysis.

    PubMed

    Mahy, N; Prats, A; Riveros, A; Andrés, N; Bernal, F

    1999-09-01

    Activation of glutamate receptors induces an excitotoxic neurodegenerative process characterised in some brain areas by the formation of calcium precipitates. To examine the pathogenesis of basal ganglia calcification (BGC), an improved procedure of X-ray microanalysis was used to study experimental excitotoxic calcification in the rat. Three weeks after injection of ibotenic acid (IBO) in the rat basal forebrain, calcified inclusions within hypertrophied astrocytes were characterised. They appeared to form part of a filamentous structure localised in the cytoplasm in association with normal mitochondria and other organelles. Larger inclusions were surrounded by reactive microglia. The main inorganic components in these deposits were Ca and P, frequently accompanied by S. Al, Si and K. The shape and Ca/P molar ratio of the large deposits (>10 microm) indicate that they may be biological apatites. Aluminosilicates were detected as small deposits (<4 microm) free of other mineral constituents. To our knowledge this is the first report showing that IBO lesion induces brain accumulation of aluminosilicates similar to that described in Alzheimer's or Fahr's patients. Our data indicate that precipitation of Ca and Al may reduce their IBO-induced increased concentration. In conclusion, the experimental model and the improved efficiency of X-ray analysis described may help us to understand the pathogenesis of BGC. PMID:10483777

  4. Detection and effects on platelet function of anti-platelet antibody in mule foals with experimentally induced neonatal alloimmune thrombocytopenia.

    PubMed

    Ramirez, S; Gaunt, S D; McClure, J J; Oliver, J

    1999-01-01

    Horse mares carrying mule foals were immunized during the last trimester of pregnancy with whole acid-citrate-dextrose-anticoagulated donkey blood to experimentally induce neonatal alloimmune thrombocytopenia. Thrombocytopenia occurred in the neonatal mule foals born to immunized horse mares within 24 hours after ingestion of their dams' colostrum. Mule foals born to mares not immunized with donkey blood did not develop thrombocytopenia. These findings suggest that antibodies may have been directed against a donkey platelet antigen present in the mule foals but not present in their dams. The objectives of this study were to determine whether anti-platelet antibody could be detected in mule foals with experimentally induced neonatal alloimmune thrombocytopenia, to identify any platelet proteins recognized by serum antibody in these foals, and to determine if platelet function was altered by sera from these mule foals. An indirect enzyme-linked immunosorbent assay demonstrated significantly higher absorption at 1:200 of platelet-bindable immunoglobulin G in serum from thrombocytopenic mule foals, compared with nonthrombocytopenic mule foals. Sera from thrombocytopenic and nonthrombocytopenic mule foals produced similar binding patterns in western immunoblots with donkey platelet proteins separated on sodium dodecyl sulfate polyacrylamide gels. Maximal platelet aggregation and relative slope of aggregation in response to collagen were significantly inhibited after incubation with sera from thrombocytopenic mule foals. These results suggest that mule foals with induced alloimmune thrombocytopenia have serum antibodies that bind to platelets and may compete with collagen binding sites to impair platelet aggregation. PMID:10587252

  5. Aquaporin 1 (AQP1) expression in experimentally induced osteoarthritic knee menisci: an in vivo and in vitro study.

    PubMed

    Musumeci, G; Leonardi, R; Carnazza, M L; Cardile, V; Pichler, K; Weinberg, A M; Loreto, C

    2013-04-01

    Osteoarthritis (OA) of the knee is a major problem in our society. The development of new treatment options for OA is limited, because the pathophysiological mechanisms are not clearly understood, especially on the molecular level. Aquaporin 1 (AQP1) is a specific protein channels for water transport; it is expressed in articular chondrocytes, human synovitis, in chondrocytes of patients with rheumatoid arthritis or OA and in chondrocyte-like cells of human intervertebral disc. The aim of this study was to investigate the expression of AQP1, through immunohistochemistry, immunocytochemistry and Western blot, in experimentally induced OA knee menisci. AQP1 was studied in vivo in knee OA menisci from 36 rats that underwent medial or lateral meniscectomy, and in vitro on fibrochondrocytes derived from knee OA menisci rats. OA in rats was experimentally induced and tested by histomorphometric analysis. Histological results demonstrated structural alterations in OA menisci accompanied by a very strong AQP1 immunohistochemical and immunocytochemical staining. The Western blot analysis confirmed a strong expression of AQP1 in OA fibrochondrocytes cells. The results of the present research suggest that an activation of AQP1, induced by the OA process, may represent an endogenous mechanism, which can be used to control the tissue degeneration within OA articular joints. PMID:23164158

  6. Effect of rosiglitazone in sodium arsenite-induced experimental vascular endothelial dysfunction.

    PubMed

    Kaur, Tajpreet; Goel, Rajesh Kumar; Balakumar, Pitchai

    2010-04-01

    The present study has been designed to investigate the effect of rosiglitazone, a peroxisome proliferator activated receptor gamma agonist in sodium arsenite-induced vascular endothelial dysfunction (VED) in rats. The rats were administered sodium arsenite (1.5 mg/kg/day, i.p., 2 weeks) to induce VED. The development of VED was assessed by employing isolated aortic ring preparation and estimating serum nitrite/nitrate concentration. Further, the integrity of the aortic endothelium was assessed histologically using haematoxylin-eosin staining. Moreover, the oxidative stress was assessed by estimating serum thiobarbituric acid reactive substances, aortic reactive oxygen species and reduced form of glutathione. The administration of sodium arsenite produced VED by impairing acetylcholine-induced endothelium dependent relaxation, diminishing the integrity of vascular endothelium and decreasing the serum nitrite/nitrate concentration. In addition, sodium arsenite was noted to produce oxidative stress as it increased serum thiobarbituric acid reactive substances and aortic reactive oxygen species and consequently decreased glutathione. Treatment with rosiglitazone (3 mg/kg/day, p.o., 2 weeks and 5 mg/kg/day, p.o., 2 weeks) significantly prevented sodium arsenite-induced VED by enhancing acetylcholine-induced endothelium dependent relaxation, improving the integrity of vascular endothelium, increasing the nitrite/nitrate concentration and decreasing the oxidative stress. However, the vascular protective effect of rosiglitazone was markedly abolished by co-administration of nitric oxide synthase inhibitor, N-Omega-Nitro-L-Arginine Methyl Ester (L-NAME) (25 mg/kg/day, i.p., 2 weeks). Thus, it may be concluded that rosiglitazone reduces oxidative stress, activates eNOS and enhances the generation of nitric oxide to prevent sodium arsenite-induced VED in rats. PMID:20422371

  7. Experimental Study on Radiation Induced Boiling Enhancement for Stainless Steel Plate

    SciTech Connect

    Koji Okamoto; Hiroshi Akiyama; Haruki Madarame; Tomoji Takamasa

    2002-07-01

    The Radiation Induced Boiling Enhancement phenomena (RIBE) were confirmed using the SUS304 foil. The SUS304 with plasma oxidized surface shows higher CHF, i.e., about 20% improvement. While, the natural and mixed gas oxidized surface does not show the boiling enhancement. The RIBE has been highly related to the surface conditions. (authors)

  8. Intranasal vaccination with proinsulin DNA induces regulatory CD4+ T cells that prevent experimental autoimmune diabetes.

    PubMed

    Every, Alison L; Kramer, David R; Mannering, Stuart I; Lew, Andrew M; Harrison, Leonard C

    2006-04-15

    Insulin, an autoantigen in type 1 diabetes, when administered mucosally to diabetes-prone NOD mice induces regulatory T cells (T(reg)) that protect against diabetes. Compared with protein, Ag encoded as DNA has potential advantages as a therapeutic agent. We found that intranasal vaccination of NOD mice with plasmid DNA encoding mouse proinsulin II-induced CD4+ T(reg) that suppressed diabetes development, both after adoptive cotransfer with "diabetogenic" spleen cells and after transfer into NOD mice given cyclophosphamide to accelerate diabetes onset. In contrast to prototypic CD4+ CD25+ T(reg), CD4+ T(reg) induced by proinsulin DNA were both CD25+ and CD25- and not defined by markers such as glucocorticoid-induced TNFR-related protein (GITR), CD103, or Foxp3. Intriguingly, despite induction of T(reg) and reduced islet inflammation, diabetes incidence in proinsulin DNA-treated mice was unchanged. However, diabetes was prevented when DNA vaccination was performed under the cover of CD40 ligand blockade, known to prevent priming of CTL by mucosal Ag. Thus, intranasal vaccination with proinsulin DNA has therapeutic potential to prevent diabetes, as demonstrated by induction of protective T(reg), but further modifications are required to improve its efficacy, which could be compromised by concomitant induction of pathogenic immunity. PMID:16585551

  9. The role of gastric mucosal histamine in acid secretion and experimentally induced lesions in the rat.

    PubMed

    Andersson, K; Mattsson, H; Larsson, H

    1990-01-01

    The role played by histamine from enterochromaffin-like (ECL) cells and mast cells in gastric acid secretion and in the development of ethanol-induced gastric lesions was studied in the rat. This was done by examining the effects of inhibition of the histamine-producing enzyme histidine decarboxylase (HDC) with alpha-fluoromethylhistidine (alpha-FMH) and the effects of degranulation of the mucosal mast cells with dexamethasone. A single dose of alpha-FMH (50 mg/kg p.o.) inhibited the HDC activity by 94% but did not affect histamine levels in the gastric mucosa 2 h after dose. Repeated treatment resulted in an almost complete inhibition of HDC activity and in a reduction of histamine levels by 75%. Pentagastrin failed to stimulate acid secretion after 4 days treatment with alpha-FMH, whereas the acid response to histamine was unaffected in chronic gastric fistula rats. Ethanol failed to induce gastric lesions in rats pretreated for 4 days with dexamethasone whereas 4 days pretreatment with alpha-FMH did not influence ethanol-induced lesion formation. The present results show that histamine synthesis is required for pentagastrin-stimulated gastric acid secretion and that mucosal mast-cell histamine plays a role in the development of ethanol-induced gastric lesions. PMID:2210091

  10. The protective effect of vildagliptin in chronic experimental cyclosporine A-induced hepatotoxicity.

    PubMed

    El-Sherbeeny, Nagla A; Nader, Manar A

    2016-03-01

    The study examined the effect of dipeptidyl peptidase-4 (DPP-4) inhibitor, vildagliptin, in cyclosporine (CsA)-induced hepatotoxicity. Rats were divided into 4 groups treated for 28 days: control (vehicle), vildagliptin (10 mg/kg, orally), CsA (20 mg/kg, s.c.), and CsA-vildagliptin group. Liver function was assessed by measuring serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (γGT), lactate dehydrogenase (LDH), and albumin, and histopathological changes of liver were examined. Oxidative stress markers were evaluated. Assessment of nuclear factor-kappa B (NF-κB) activity in hepatic nuclear extract, serum DPP-4, and expression of Bax and Bcl2 were also done. CsA-induced hepatotoxicity was evidenced by increase in serum levels of AST, ALT, and γGT; a decrease in serum albumin; and a significant alteration in hepatic architecture. Also, significant increase in thiobarbituric acid reactive substance (TBARS) and decrease in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione (GSH) levels, increased expression Bax proteins with deceased expression of Bcl2, and increased hepatic activity of NF-κB and serum DPP-4 level were observed upon CsA treatment. Vildagliptin significantly improved all altered parameters induced by CsA administration. Vildagliptin has the potential to protect the liver against CsA-induced hepatotoxicity by reducing oxidative stress, DPP-4 activity, apoptosis, and inflammation. PMID:26632647

  11. Histological Experimental Study on the Effect of Stem Cell Therapy on Adriamycin Induced Chemobrain

    PubMed Central

    El Aziz, Dalia Hussein Abd; Metwally, Hala Gabr

    2013-01-01

    Background and Objectives: Negative consequences of chemotherapy on brain function were suggested and were addressed in animal models as the clinical phenomenon of chemobrain .It was postulated that adriamycin (ADR) induce changes in behaviour and in brain morphology. Human umbilical cord mesenchymal stem cells (HUCMSCs) could be induced to differentiate into neuron-like cells .The present study aimed at investigating the possible therapeutic effect of HUCMSC therapy on adriamycin induced chemobrain in rat. Methods and Results: Twenty five female albino rats were divided into control group, ADR group where rats were given single intraperitoneal (IP) injection of 5 mg/kg ADR. The rats were sacrificed two and four weeks following confirmation of brain damage. In stem cell therapy group, rats were injected with HUCMSCs following confirmation of brain damage and sacrificed two and four weeks after therapy. Brain sections were exposed to histological, histochemical, immunohistochemical and morphometric studies. In ADR group, multiple shrunken neurons exhibiting dark nuclei and surrounded by vacuoles were seen .In response to SC therapy ,multiple normal pyramidal nerve cells were noted. The area of shrunken nerve cells exhibiting dark nuclei, Prussion blue and CD105 positive cells were significantly different in ADR group in comparison to SC therapy group. Conclusions: ADR induced progressive duration dependant cerebral degenerative changes. These changes were ameliorated following cord blood human mesenchymal stem cell therapy. A reciprocal relation was recorded between the extent of regeneration and the existence of undifferentiated mesenchymal stem cells. PMID:24386554

  12. EXPERIMENTAL PULMONARY EMPHYSEMA INDUCED IN THE RAT BY INTRATRACHEALLY ADMINISTERED ELASTASE: MORPHOGENESIS

    EPA Science Inventory

    Emphysema was produced experimentally in rats by administration of porcine pancreatic elastase at dose levels of 75, 100, 125, and 150 units elastase activity/100 g body wt. All doses studied were equally effective in producing emphysema. Dose levels of over 75 units activity/100...

  13. Effect of fluticasone/salmeterol combination on dyspnea and respiratory mechanics in mild-to-moderate COPD.

    PubMed

    Guenette, Jordan A; Webb, Katherine A; O'Donnell, Denis E

    2013-05-01

    The purpose of this exploratory physiological study was to evaluate the effects of inhaled fluticasone/salmeterol combination (FSC) on sensory and physiological responses to exercise in subjects with mild-to-moderate COPD. In a randomized, double-blind, placebo-controlled, crossover study, subjects underwent 6-week treatments with FSC or placebo (PLA). Detailed pulmonary function and constant-work rate cycle exercise tests were performed following each treatment period. Fifteen subjects completed the study (mean ± SD): age 64 ± 10 years; smoking history 47 ± 29 pack-years; post-bronchodilator forced expiratory volume in 1 s 86 ± 15 %predicted (10 mild and 5 moderate COPD); peak incremental oxygen uptake 71 ± 16 %predicted. Compared with PLA, FSC treatment was associated with improved: FEV1 by 0.23 ± 0.18 L; inspiratory capacity by 0.18 ± 0.23 L; functional residual capacity by -0.28 ± 0.30 L; and specific airways resistance by -4.6 ± 4.5 cmH2O s (all p < 0.01). There were no significant changes in dyspnea intensity throughout exercise and endurance time did not change significantly (1.2 ± 3.0 min, p = 0.149). Following FSC, inspiratory capacity at rest and throughout exercise increased by 0.2-0.3 L with concomitant increases in tidal volume and ventilation (p < 0.05). Compared with PLA, the work of breathing and the ratio of respiratory muscle effort to tidal volume improved with FSC during exercise (p < 0.05). In mild-to-moderate COPD, FSC was associated with significant improvements in airway function at rest and during exercise. Despite important mechanical improvements, there were no significant effects on dyspnea intensity and exercise endurance. PMID:23421968

  14. Measured and computed induced body currents in front of an experimental RF dielectric heater.

    PubMed

    Kännälä, Sami; Puranen, Lauri; Sihvonen, Ari-Pekka; Jokela, Kari

    2008-02-01

    Operators of industrial high-frequency dielectric heaters are exposed to electromagnetic fields that are high enough to significantly increase body temperature. The assessment of exposure based on the measurement of external field strengths is, however, inaccurate due to the non-uniformity of the fields. This paper presents an exposure assessment method based on the measurement of the current induced by the external electric field in the body of the operator. Body current distributions were measured at 27.12 MHz using various current meters under a condition simulating the exposure to stray fields emitted by a dielectric heater. The specific absorption rates and induced body currents were computed with the finite-difference time-domain method using heterogeneous and homogeneous human models. The numerical analysis indicated that the basic restrictions for occupational exposure are not exceeded when the current induced in the limbs is lower than the action level (100 mA), even though the maximum electric field significantly exceeds the action value (61 V m(-1)). For the heterogeneous human model the exposure limit for local specific absorption rate was exceeded when the current induced in the ankle was 166 mA at a distance of 0.3 m from the electrode of the device. The vertical component of current density proved to be much more significant than the horizontal components. The importance of the horizontal components was highest near the electrode. The computations showed no concentration of the induced current to the superficial tissues due to the skin effect. PMID:18188050

  15. Experimental and numerical investigations on flashing-induced instabilities in a single channel

    SciTech Connect

    Marcel, Christian P.; Rohde, M.; Van Der Hagen, T.H.J.J.

    2009-11-15

    During the start-up phase, natural circulation BWRs (NC-BWRs) need to be operated at low pressure conditions. Such conditions favor flashing-induced instabilities due to the large hydrostatic pressure drop induced by the tall chimney. Moreover, in novel NC-BWR designs the steam separation is performed in the steam separators which create large pressure drops at the chimney outlet, which effect on stability has not been investigated yet. In this work, flashing-induced oscillations occurring in a tall, bottom heated channel are numerically investigated by using a simple linear model with three regions and an accurate implementation for estimating the water properties. The model is used to investigate flashing-induced instabilities in a channel for different values of the core inlet friction value. The results are compared with experiments obtained by using the CIRCUS facility at the same conditions, showing a good agreement. In addition, the experiments on flashing-induced instabilities are presented in a novel manner allowing visualizing new details of the phenomenon numerical stability investigations on the effect of the friction distribution are also done. It is found that by increasing the total restriction in the channel the system is destabilized. In addition, the chimney outlet restriction has a stronger destabilizing effect than the core inlet restriction. A stable two-phase region is observed prior to the instabilities in the experiments and the numerical simulations which may help to pressurize the vessel of NC-BWRs and thus reducing the effects of flashing instabilities during start-up. (author)

  16. In Vitro and in Vivo Experimental Studies on Trabecular Meshwork Degeneration Induced by Benzalkonium Chloride (An American Ophthalmological Society Thesis)

    PubMed Central

    Baudouin, Christophe; Denoyer, Alexandre; Desbenoit, Nicolas; Hamm, Gregory; Grise, Alice

    2012-01-01

    Purpose: Long-term antiglaucomatous drug administration may cause irritation, dry eye, allergy, subconjunctival fibrosis, or increased risk of glaucoma surgery failure, potentially due to the preservative benzalkonium chloride (BAK), whose toxic, proinflammatory, and detergent effects have extensively been shown experimentally. We hypothesize that BAK also influences trabecular meshwork (TM) degeneration. Methods: Trabecular specimens were examined using immunohistology and reverse transcriptase–polymerase chain reaction. A trabecular cell line was stimulated by BAK and examined for apoptosis, oxidative stress, fractalkine and SDF-1 expression, and modulation of their receptors. An experimental model was developed with BAK subconjunctival injections to induce TM degeneration. Mass spectrometry (MS) imaging assessed BAK penetration after repeated instillations in rabbit eyes. Results: Trabecular specimens showed extremely low densities of trabecular cells and presence of cells expressing fractalkine and fractalkine receptor and their respective mRNAs. Benzalkonium in vitro induced apoptosis, oxidative stress, and fractalkine expression and inhibited the protective chemokine SDF-1 and Bcl2, also inducing a sustained intraocular pressure (IOP) increase, with dramatic apoptosis of trabecular cells and reduction of aqueous outflow. MS imaging showed that BAK could access the TM at measurable levels after repeated instillations. Conclusion: BAK enhances all characteristics of TM degeneration typical of glaucoma—trabecular apoptosis, oxidative stress, induction of inflammatory chemokines—and causes degeneration in acute experimental conditions, potentially mimicking long-term accumulation. BAK was also shown to access the TM after repeated instillations. These findings support the hypothesis that antiglaucoma medications, through toxicity of their preservative, may cause further long-term trabecular degeneration and therefore enhance outflow resistance, reducing the

  17. Long-pulse laser-induced damage in an optical anti-reflective film: II. Experimental research

    NASA Astrophysics Data System (ADS)

    Li, Changli; Ma, Yao; Wang, Di; Wang, Zhiyang; Zhang, Xihe; Liu, Haiming

    2014-12-01

    In order to verify the result of theoretical analysis about long-pulse flat-topped multi-Gaussian laser-induced damage in an optical anti-reflection film with HfO2/SiO2 composite film coating on a BK7 substrate (BK7:HfO2/SiO2), an experimental system was built, which carried out the experiment and analysis, focusing on the pulse-length 1.0 ms, flat-topped laser-induced damage. The result shows that the thermal effect is the main reason for damage under the long-pulse flat-topped laser. Moreover, the stripping and shedding occur because of the heating stress of the film happening at an early stage of the laser irradiation. However, the crack happens at laser irradiation termination. The correctness of the theoretical analysis results is verified.

  18. [Prevention of osteoporosis by foods and dietary supplements. Milk basic protein (MBP) induces alveolar bone formation in rat experimental periodontitis].

    PubMed

    Seto, Hiroyuki; Nagata, Toshihiko

    2006-10-01

    Periodontitis is a chronic inflammatory disease caused by infection of periodontopathic bacteriae, which induced alveolar bone resorpotion. Milk basic protein (MBP) has been reported to be useful as a supplement because of increasing bone formation in animal and human studies. We examined the effect of MBP for alveolar bone formation in rat experimental periodontitis. After alveolar bone resorption was induced by ligature technique, the diets containing low and high dose of MBP were given to rats for 90 days. Micro-focus computed tomography and histological observation revealed a recovery of alveolar bone in high-dose MBP group compared to the control group. Osteoid thickness of alveolar bone crest significantly increased in low and high-dose MBP groups. These findings indicate that MBP may be effective for the recovery of alveolar bone resorption in periodontitis. PMID:17012815

  19. Ceruletide increases dose dependently both jejunal motor activity and threshold and tolerance to experimentally induced pain in healthy man.

    PubMed Central

    Stacher, G; Steinringer, H; Schmierer, G; Schneider, C; Winklehner, S; Mittelbach, G; De Paolis, C; Praga, C

    1984-01-01

    The effects of ceruletide on jejunal motility and experimentally induced pain were studied in 16 healthy men, who participated each in four experiments and received in random double blind fashion 5, 10, or 20 micrograms ceruletide intramuscularly or placebo. Jejunal pressures were recorded by three perfused catheters with orifices between 10 and 20 cm aboral of the ligament of Treitz. Ceruletide dose dependently diminished phase I and increased phase II type activity and tended to reduce the number, but not the duration, of activity fronts. The number and amplitude of contractions as well as the area under the curve increased significantly and dose dependently as did threshold and tolerance to electrically and threshold to thermally induced pain. Only mild sedative and other side effects occurred. PMID:6714795

  20. Numerical and experimental investigation of the influence of tumor size on laser-induced ultrasonics in soft tissue

    NASA Astrophysics Data System (ADS)

    An, Rongrong; Luo, Xiaosen; Shen, Zhonghua

    2014-04-01

    The generation and propagation of laser-induced ultrasonic waves in soft tissue systems are investigated using the finite element method. Taking into account the effects of thermal diffusion, optical penetration, tumor elastic modulus and finite laser pulse duration, the transient temperature distribution is obtained. Using this temperature field as thermal loading in structural analysis, the thermoelastic stress field and laser-induced ultrasound waves in soft tissues are obtained. The results show that the intensity of the positive peak in the ultrasound wave increases and the arrival of the longitudinal wave takes place sooner as the tumor size becomes larger. It is also found that the duration of the laser ultrasound signal becomes shorter as the size of the tumor decreases. Meanwhile, the percentage of the received ultrasonic signal in the high-frequency region increases as the size of the tumor decreases, as has been proved by the experimental results.

  1. Inclusion body disease of cranes: comparison of pathologic findings in cranes with acquired vs. experimentally induced disease

    USGS Publications Warehouse

    Schuh, J.C.; Sileo, L.; Siegfried, L.M.; Yuill, Thomas M.

    1986-01-01

    Inclusion body disease of cranes was the cause of death in 17 immature and mature cranes of 5 different species in Wisconsin. A herpesvirus of unknown origin was the apparent cause. An isolate of this herpesvirus was used to experimentally infect 3 species of cranes. Macroscopic and microscopic lesions associated with naturally acquired and experimentally induced disease were essentially identical. Multifocal hepatic and splenic necrosis was found in all cranes evaluated. Necrosis of the gastrointestinal tract, thymus, and bursa of Fabricius also was seen in some of the cranes. Eosinophilic intranuclear inclusion bodies often were commonly associated with hepatic lesions, sometimes with the splenic lesions, and rarely with the thymic or gastrointestinal tract lesions. The lesions of this inclusion body disease were similar to those reported for cranes in Austria from which a crane herpesvirus was isolated.

  2. Experimentally induced pigment changes in small African 'Barbus' (Teleostei: Cyprinidae): Synonymy of 'Barbus' amphigramma and 'Barbus' taitensis with 'Barbus' paludinosus

    USGS Publications Warehouse

    Farm, Brian P.

    2001-01-01

    Pigmentation in fishes is known to be variable both among individuals of a species and within individuals over time. Use of pigment characters for taxonomic diagnoses must, therefore, be carefully considered. I present experimental evidence showing that pigment characters previously considered diagnostic for three small African 'Barbus' species may differ between living and preserved specimens and that lasting changes in these characters can be induced experimentally by placing fishes in a different, less turbid environment. Lateral line pigmentation and presence of a spot on the caudal peduncle showed significant changes that resulted in different species identifications before and after the experiment. These pigment patterns are thereby shown to be labile, nontrenchant characters having little or no diagnostic utility. 'Barbus' amphigramma Boulenger, 1903, and 'Barbus' taitensis Gu??nther, 1894, are thus shown to be junior synonyms of 'Barbus' paludinosus Peters, 1852.

  3. Cisplatin-Induced Non-Oliguric Acute Kidney Injury in a Pediatric Experimental Animal Model in Piglets

    PubMed Central

    Lázaro, Alberto; González, Rafael; Urbano, Javier; López, Jorge; Solana, Maria José; Toledo, Blanca; del Castillo, Jimena; Tejedor, Alberto; López-Herce, Jesús

    2016-01-01

    Objective To design an experimental pediatric animal model of acute kidney injury induced by cisplatin. Methods Prospective comparative observational animal study in two different phases. Acute kidney injury was induced using three different doses of cisplatin (2, 3 and 5 mg/kg). The development of nephrotoxicity was assessed 2 to 4 days after cisplatin administration by estimating biochemical parameters, diuresis and renal morphology. Analytical values and renal morphology were compared between 15 piglets treated with cisplatin 3 mg/kg and 15 control piglets in the second phase of the study. Results 41 piglets were studied. The dose of 3 mg/kg administered 48 hours before the experience induced a significant increase in serum creatinine and urea without an increase in potassium levels. Piglets treated with cisplatin 3 mg/kg had significantly higher values of creatinine, urea, phosphate and amylase, less diuresis and lower values of potassium, sodium and bicarbonate than control piglets. Histological findings showed evidence of a dose-dependent increase in renal damage. Conclusions a dose of 3 mg/kg of cisplatin induces a significant alteration in renal function 48 hours after its administration, so it can be used as a pediatric animal model of non-oliguric acute kidney injury. PMID:26871589

  4. Toll-like Receptors-2 and 4 are overexpressed in an experimental model of particle-induced osteolysis

    PubMed Central

    Valladares, Roberto D.; Nich, Christophe; Zwingenberger, Stefan; Li, Chenguang; Swank, Katherine R.; Gibon, Emmanuel; Rao, Allison J.; Yao, Zhenyu; Goodman, Stuart B.

    2014-01-01

    Aseptic loosening secondary to particle-associated periprosthetic osteolysis remains a major cause of failure of total joint replacements (TJR) in the mid- and long-term. As sentinels of the innate immune system, macrophages are central to the recognition and initiation of the inflammatory cascade which results in the activation of bone resorbing osteoclasts. Toll-like receptors (TLRs) are involved in the recognition of pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPS). Experimentally, polymethylmethacrylate (PMMA) and polyethylene (PE) particles have been shown to activate macrophages via the TLR pathway. The specific TLRs involved in PE particle-induced osteolysis remain largely unknown. We hypothesized that TLR-2, -4 and -9 mediated responses play a critical role in the development of PE wear particle-induced osteolysis in the murine calvarium model. To test this hypothesis, we first demonstrated that PE particles caused observable osteolysis, visible by microCT and bone histomorphometry when the particles were applied to the calvarium of C57BL/6 mice. The number of TRAP positive osteoclasts was significantly greater in the PE-treated group when compared to the control group without particles. Finally, using immunohistochemistry, TLR-2 and TLR-4 were highly expressed in PE particle-induced osteolytic lesions, whereas TLR-9 was downregulated. TLR-2 and -4 may represent novel therapeutic targets for prevention of wear particle-induced osteolysis and accompanying TJR failure. PMID:24115330

  5. Antioxidant, lipid lowering, and membrane stabilization effect of sesamol against doxorubicin-induced cardiomyopathy in experimental rats.

    PubMed

    Chennuru, Anusha; Saleem, Mohamed T S

    2013-01-01

    The present study was designed to evaluate the cardioprotective effect of sesamol against doxorubicin-induced cardiomyopathy in rats. In this study, the cardioprotective effect of sesamol against doxorubicin induced cardiomyopathy in experimental rats was evaluated at the dosage of 50 mg/kg bw. Doxorubicin was administered to rats at a total cumulative dose of 15 mg/kg through intraperitoneal route for 2 weeks in six-divided dose on 8th, 10th, 14th, 16th, 18th, and 21st day. After the last dose administration, the endogenous antioxidants and lipid peroxidation were estimated in heart tissue homogenate. Cardiac biomarkers such as troponin T, LDH, CK, and AST and lipid profiles such as cholesterol, triglycerides, HDL, LDL, and VLDL were estimated in serum. Sesamol has cardioprotective activity through normalization of doxorubicin-induced-altered biochemical parameters. Biochemical study was further supported by histopathological study, which shows that sesamol offered myocardial protection from necrotic damage. From these findings, it has been concluded that the sesamol has significant cardioprotection against doxorubicin induced cardiomyopathy via amelioration of oxidative stress, lipid lowering, and membrane stabilization effect. PMID:24228260

  6. Polyethylene glycol-induced internalization of bacteria into fungal protoplasts: Electron microscopic study and optimization of experimental conditions

    SciTech Connect

    Guerra-Tschuschke, I.; Martin, I.; Gonzalez, M.T. )

    1991-05-01

    The authors studied the mechanism of internalization of Escherichia coli into Saccharomyces cerevisiae induced by polyethylene glycol (PEG) and optimized the experimental conditions. Transmission electron microscope studies revealed that the principal factor involved in the internalization was the degree of cell aggregation attained. Internalization occurred mainly by an endocytosis-like mechanism and took place during the elimination of PEG. The optimum conditions were to treat a mixed pellet of both microorganisms with 15% PEG and then gradually dilute the polymer. The same conditions were applied to E. coli and Aspergillus nidulans, with similar results.

  7. Axisymmetric and non-axisymmetric exhaust jet induced effects on a V/STOL vehicle design. Part 3: Experimental technique

    NASA Technical Reports Server (NTRS)

    Schnell, W. C.

    1982-01-01

    The jet induced effects of several exhaust nozzle configurations (axisymmetric, and vectoring/modulating varients) on the aeropropulsive performance of a twin engine V/STOL fighter design was determined. A 1/8 scale model was tested in an 11 ft transonic tunnel at static conditions and over a range of Mach Numbers from 0.4 to 1.4. The experimental aspects of the static and wind-on programs are discussed. Jet effects test techniques in general, fow through balance calibrations and tare force corrections, ASME nozzle thrust and mass flow calibrations, test problems and solutions are emphasized.

  8. An innovative experimental setup for the measurement of sputtering yield induced by keV energy ions

    NASA Astrophysics Data System (ADS)

    Salou, P.; Lebius, H.; Benyagoub, A.; Langlinay, T.; Lelièvre, D.; Ban-d'Etat, B.

    2013-09-01

    An innovative experimental equipment allowing to study the sputtering induced by ion beam irradiation is presented. The sputtered particles are collected on a catcher which is analyzed in situ by Auger electron spectroscopy without breaking the ultra high vacuum (less than 10-9 mbar), avoiding thus any problem linked to possible contamination. This method allows to measure the angular distribution of sputtering yield. It is now possible to study the sputtering of many elements such as carbon based materials. Preliminary results are presented in the case of highly oriented pyrolytic graphite and tungsten irradiated by an Ar+ beam at 2.8 keV and 7 keV, respectively.

  9. The histamine H4 -receptor (H4 R) regulates eosinophilic inflammation in ovalbumin-induced experimental allergic asthma in mice.

    PubMed

    Hartwig, Christina; Munder, Antje; Glage, Silke; Wedekind, Dirk; Schenk, Heiko; Seifert, Roland; Neumann, Detlef

    2015-04-01

    Via the histamine H4 -receptor (H4 R), histamine promotes the pathogenesis of experimental allergic asthma in mice. Application of H4 R antagonists during sensitization as well as during provocation reduces the severity of the disease. However, the specific cell types functionally expressing H4 R in experimental allergic asthma have not been well characterized in vivo. In this study, we identified the cell type(s) responsible for H4 R activity in experimental asthma and related physiological mechanisms. Using H4 R-deficient mice, we studied the role of H4 R in the sensitization and effector phase. DCs lacking H4 R expression during the in vitro sensitization reaction resulted in effector T cells unable to induce an entire eosinophilic inflammation in the lung upon adoptive transfer in vivo. Recipient mice lacking H4 R expression, which were adoptively transferred with H4 R(+/+) T cells polarized in the presence of H4 R(+/+) DCs, showed reduced signs of inflammation and ameliorated lung function. Here, we provide in vivo evidence that in experimental asthma in mice the H4 R specifically regulates activation of DCs during sensitization, while in the effector phase the H4 R is active in cells involved in the activation of eosinophils, and possibly other cells. A putative therapy targeting the H4 R may be an option for asthma patients developing IL-5-dependent eosinophilia. PMID:25501767

  10. Experimental study on light induced influence model to mice using support vector machine

    NASA Astrophysics Data System (ADS)

    Ji, Lei; Zhao, Zhimin; Yu, Yinshan; Zhu, Xingyue

    2014-08-01

    Previous researchers have made studies on different influences created by light irradiation to animals, including retinal damage, changes of inner index and so on. However, the model of light induced damage to animals using physiological indicators as features in machine learning method is never founded. This study was designed to evaluate the changes in micro vascular diameter, the serum absorption spectrum and the blood flow influenced by light irradiation of different wavelengths, powers and exposure time with support vector machine (SVM). The micro images of the mice auricle were recorded and the vessel diameters were calculated by computer program. The serum absorption spectrums were analyzed. The result shows that training sample rate 20% and 50% have almost the same correct recognition rate. Better performance and accuracy was achieved by third-order polynomial kernel SVM quadratic optimization method and it worked suitably for predicting the light induced damage to organisms.

  11. Experimental Research on Plasma Induced by TEA CO2 Laser Propulsion

    NASA Astrophysics Data System (ADS)

    Lu, Hong; Cheng, Zuhai; Zuo, Duluo; Zhai, Bingjie; Yu, Liangying; Zhu, Haihong

    2008-04-01

    Results in the air-breathing propulsion experiments with a parabolic light craft and a self-made UV-preionized 100 J TEA CO2 laser device are presented. Air disturbance and the spectrum of the plasma after the interaction of pulsed laser radiation with the light craft were studied. It was found that the focal length of the parabolic light craft had a significant effect on the air-disturbance. Two shock waves were detected for the longer focal length, while only one shock wave detected for the short focal length. The spectrum of the laser-induced plasma, the distribution of the characteristic lines, and the temporal behaviors of the air plasma were studied in detail. The results showed that, the evolution of the laser-induced plasma lasted 20 μs, and the plasma spectrum would reach the maximum intensity at 7 μs.

  12. Experimental Evaluation of Neutron Induced Noise on Gated X-ray Framing Cameras

    SciTech Connect

    Izumi, N; Stone, G; Hagmann, C; Sorce, C; Bradley, D K; Moran, M; Landen, O L; Stoeffl, W; Springer, P; Tommasini, R; Hermann, H W; Kyrala, G A; Glebov, V Y; Sangster, T C; Koch, J A

    2009-10-08

    A micro-channel plate based temporally-gated x-ray camera (framing camera) is one of the most versatile diagnostic tools of inertial confinement fusion experiments; particularly for observation of the shape of x-ray self emission from compressed core of imploded capsules. However, components used in an x-ray framing camera have sensitivity to neutrons induced secondary radiations. On early low-yield capsule implosions at the National Ignition Facility (NIF), the expected neutron production is about 5 x 10{sup 14}. Therefore, the expected neutron fluence at a framing camera located {approx} 150 cm from the object is 2 x 10{sup 9} neutrons/cm{sup 2}. To obtain gated x-ray images in such harsh neutron environments, quantitative understanding of neutron-induced backgrounds is crucial.

  13. Hybrid predictions of railway induced ground vibration using a combination of experimental measurements and numerical modelling

    NASA Astrophysics Data System (ADS)

    Kuo, K. A.; Verbraken, H.; Degrande, G.; Lombaert, G.

    2016-07-01

    Along with the rapid expansion of urban rail networks comes the need for accurate predictions of railway induced vibration levels at grade and in buildings. Current computational methods for making predictions of railway induced ground vibration rely on simplifying modelling assumptions and require detailed parameter inputs, which lead to high levels of uncertainty. It is possible to mitigate against these issues using a combination of field measurements and state-of-the-art numerical methods, known as a hybrid model. In this paper, two hybrid models are developed, based on the use of separate source and propagation terms that are quantified using in situ measurements or modelling results. These models are implemented using term definitions proposed by the Federal Railroad Administration and assessed using the specific illustration of a surface railway. It is shown that the limitations of numerical and empirical methods can be addressed in a hybrid procedure without compromising prediction accuracy.

  14. Experimental evidence on removing copper and light-induced degradation from silicon by negative charge

    SciTech Connect

    Boulfrad, Yacine Lindroos, Jeanette; Yli-Koski, Marko; Savin, Hele; Wagner, Matthias; Wolny, Franziska

    2014-11-03

    In addition to boron and oxygen, copper is also known to cause light-induced degradation (LID) in silicon. We have demonstrated previously that LID can be prevented by depositing negative corona charge onto the wafer surfaces. Positively charged interstitial copper ions are proposed to diffuse to the negatively charged surface and consequently empty the bulk of copper. In this study, copper out-diffusion was confirmed by chemical analysis of the near surface region of negatively/positively charged silicon wafer. Furthermore, LID was permanently removed by etching the copper-rich surface layer after negative charge deposition. These results demonstrate that (i) copper can be effectively removed from the bulk by negative charge, (ii) under illumination copper forms a recombination active defect in the bulk of the wafer causing severe light induced degradation.

  15. Experimental study of induced inflammation in the Brazilian Boa (Boa constrictor constrictor).

    PubMed

    Tucunduva, M; Borelli, P; Silva, J R

    2001-01-01

    The objective of this work was to identify the cellular types present in inflammatory processes in the Brazilian snake, Boa constrictor constrictor. Blood smears were first made from three normal snakes and stained by several methods to identify the cell types present, thus facilitating the identification of cells in inflammatory processes induced in 16 further snakes by the subcutaneous implantation of cotton suture threads and circular coverslips. Implanted threads induced migration of heterophils and monocytes after 4 h, more intense monocyte migration after 24 h, an intense granulocytic migration inside and around the thread after 48 h, heterophilic granulocytes, macrophages and giant cells after 7 days, and giant cells with a typical granuloma response and persistence of heterophilic cells after 15, 69 and 117 days. The cell population attached to the implanted coverslips after 4 h was composed of heterophils, thrombocytes, erythrocytes and macrophages; after 24 and 48 h heterophils predominated, and after 7 days heterophils, macrophages and giant cells predominated. PMID:11578134

  16. Experimental investigation on dynamic characteristics and strengthening mechanism of laser-induced cavitation bubbles.

    PubMed

    Ren, X D; He, H; Tong, Y Q; Ren, Y P; Yuan, S Q; Liu, R; Zuo, C Y; Wu, K; Sui, S; Wang, D S

    2016-09-01

    The dynamic features of nanosecond laser-induced cavitation bubbles near the light alloy boundary were investigated with the high-speed photography. The shock-waves and the dynamic characteristics of the cavitation bubbles generated by the laser were detected using the hydrophone. The dynamic features and strengthening mechanism of cavitation bubbles were studied. The strengthening mechanisms of cavitation bubble were discussed when the relative distance parameter γ was within the range of 0.5-2.5. It showed that the strengthening mechanisms caused by liquid jet or shock-waves depended on γ much. The research results provided a new strengthening method based on laser-induced cavitation shotless peening (CSP). PMID:27150764

  17. Anticonvulsant activity of methanolic and aqueous extracts of Melissa parviflora in experimentally induced Swiss albino mice

    PubMed Central

    Bhat, Jalal Uddin; Nizami, Qudsia; Asiaf, Asia; Parray, Shabir Ahmad; Ahmad, Shiekh Tanveer; Aslam, Mohammad; Khanam, Razia; Mujeeb, Mohammad; Umar, Sadiq; Siddiqi, Ayesha

    2012-01-01

    The aim of the present study was to evaluate the anticonvulsant effect of whole plant extracts of Melissa parviflora using MES and PTZ induced seizures models. The dried whole plant was subjected to extraction in methanol and water. The extracts were subjected to phytochemical tests and the carbohydrate, flavonols, coumarins, glycosides and steroid were found to be present. The methanolic and aqueous extracts of the plant of Melissa parviflora were observed for their anticonvulsant activity by Maximal Electroshock seizures (MES) test and Pentylenetetrazole (PTZ) test using Swiss albino mice. Both the extracts showed significant activity in MES and PTZ induced convulsions in comparison to control. From the literature surveys as well experiments performed, it can be said that Melissa parviflora does pose anticonvulsant property. PMID:27298604

  18. Enhanced growth and experimental metastasis of chemically induced tumor in ultraviolet irradiated syngeneic mice.

    PubMed

    Gensler, H L; Chen, H

    1991-05-01

    Recent studies have shown that ultraviolet (UV) irradiation induces a systemic effect which enhances subsequent tumor induction by benzo[a]pyrene in a manner which is dependent on the dose of benzo[a]pyrene. The present study was designed to test whether UV-B irradiation renders mice susceptible to subcutaneous or intravenous injection of a regressor tumor induced by benzo[a]pyrene. The sources of UV-B irradiation were banks of 6 Westinghouse FS-40 sunlamps, situated 20 cm above the mouse cages. Female BALB/cAnNHsd received five 30-min dorsal UV-B radiation treatments per week for 12 weeks, resulting in a total dose of approx. 6.4 x 10(5) J m-2. Two to seven days after termination of UV treatments, syngeneic regressor tumor cells (BP2) induced by benzo[a]pyrene were injected subcutaneously or intravenously into irradiated mice and unirradiated controls. By 38 days post subcutaneous implantation, 24/30 and 3/30 BP2 implants were detectable in the irradiated and unirradiated mice, respectively. Ultraviolet irradiated mice were also unable to reject lung colonies resulting from intravenous administration of BP2 cells, although they were rejected by unirradiated mice. The mean number of lung colonies per mouse was 16- to 35-fold greater in UV irradiated mice than in unirradiated controls, at 14 to 17 days post injection. Thus, UV irradiation rendered mice, with no known exposure to benzo[a]pyrene, susceptible to a subcutaneous or intravenous injection of a regressor tumor induced by benzo[a]pyrene. PMID:1881963

  19. TR PIV Experimental Investigation on Bypass Transition Induced by a Cylinder Wake

    NASA Astrophysics Data System (ADS)

    Tang, Z. Q.; Jiang, N.

    2011-09-01

    The process of laminar to turbulent transition induced by a cylinder wake was studied by TR PIV in a water channel. The generation of secondary transverse vortex structure and its evolution along the streamwise are tracked, also, a low-speed hump is found in the near-wall region along the bypass transition zone, which becomes more obvious further downstream. At the later stage, hairpin vortex can be seen, and its head is almost vertical to the wall.

  20. Fractal Dimension in Quantifying Experimental-Pulmonary-Hypertension-Induced Cardiac Dysfunction in Rats

    PubMed Central

    Pacagnelli, Francis Lopes; Sabela, Ana Karênina Dias de Almeida; Mariano, Thaoan Bruno; Ozaki, Guilherme Akio Tamura; Castoldi, Robson Chacon; do Carmo, Edna Maria; Carvalho, Robson Francisco; Tomasi, Loreta Casquel; Okoshi, Katashi; Vanderlei, Luiz Carlos Marques

    2016-01-01

    Background Right-sided heart failure has high morbidity and mortality, and may be caused by pulmonary arterial hypertension. Fractal dimension is a differentiated and innovative method used in histological evaluations that allows the characterization of irregular and complex structures and the quantification of structural tissue changes. Objective To assess the use of fractal dimension in cardiomyocytes of rats with monocrotaline-induced pulmonary arterial hypertension, in addition to providing histological and functional analysis. Methods Male Wistar rats were divided into 2 groups: control (C; n = 8) and monocrotaline-induced pulmonary arterial hypertension (M; n = 8). Five weeks after pulmonary arterial hypertension induction with monocrotaline, echocardiography was performed and the animals were euthanized. The heart was dissected, the ventricles weighed to assess anatomical parameters, and histological slides were prepared and stained with hematoxylin/eosin for fractal dimension analysis, performed using box-counting method. Data normality was tested (Shapiro-Wilk test), and the groups were compared with non-paired Student t test or Mann Whitney test (p < 0.05). Results Higher fractal dimension values were observed in group M as compared to group C (1.39 ± 0.05 vs. 1.37 ± 0.04; p < 0.05). Echocardiography showed lower pulmonary artery flow velocity, pulmonary acceleration time and ejection time values in group M, suggesting function worsening in those animals. Conclusion The changes observed confirm pulmonary-arterial-hypertension-induced cardiac dysfunction, and point to fractal dimension as an effective method to evaluate cardiac morphological changes induced by ventricular dysfunction. PMID:27223643

  1. Cholinesterase activity in rat liver and serum during experimentally induced inflammation.

    PubMed

    Simon, G; Budavári, I

    1977-01-01

    Cholinesterase activity of albino rats with acute local oedematous inflammation induced by turpentine, croton oil or Freund's adjuvant was elevated in the liver homogenate but decreased in the serum. Aprotinin administration prevented the decrease of serum activity. In the oedema fluid of rats treated with croton oil an enzyme with cholinester splitting activity was detected and it was shown to be identical with serum cholinesterase (EC 3. 1. 1. 8.). PMID:311577

  2. Hypoglycemic effect of Aloe vera gel on streptozotocin-induced diabetes in experimental rats.

    PubMed

    Rajasekaran, S; Sivagnanam, K; Ravi, K; Subramanian, S

    2004-01-01

    In the present study an attempt has been made to evaluate the presence of hypoglycemic activity in the alcoholic extract of Aloe vera gel. Effects of oral administration of A. vera extract at a concentration of 200 and 300 mg/kg of body weight on (a) normal fasted rats, (b) oral glucose-loaded rats, and (c) streptozotocin-induced diabetic rats have been studied. A. vera extract maintain the glucose homeostasis by controlling the carbohydrate metabolizing enzymes. PMID:15117555

  3. Experimental investigation of lateral forces induced by flow through model labyrinth glands

    NASA Technical Reports Server (NTRS)

    Leong, Y. M. M. S.; Brown, R. D.

    1984-01-01

    The lateral forces induced by flow through model labyrinth glands were investigated. Circumferential pressure distributions, lateral forces and stiffness coefficients data obtained are discussed. The force system is represented as a negative spring and a tangential force orthogonal to eccentricity. The magnitude of these forces are dependent on eccentricity, entry swirl, rotor peripheral velocity and seal size. A pressure equalization chamber at midgland tests should in significantly reduced forces and stiffness coefficients.

  4. Treatment for chronic ischaemia-induced bladder detrusor dysfunction using bone marrow mesenchymal stem cells: an experimental study.

    PubMed

    Chen, Song; Zhang, Hai-Yan; Zhang, Ning; Li, Wei-Hong; Shan, Hui; Liu, Ke; Yang, Yong

    2012-03-01

    The mechanism of ischaemia-induced bladder dysfunction is not entirely clear, but is thought to be a result of the ischaemia-related M-receptor hypersensitivity to acetylcholine. In addition to nerve injury, ischaemia may cause bladder detrusor fibrosis and urethra de-epithelialization. Bladder dysfunctions caused by bladder outlet obstruction (BOO) and aging detrusor were considered to be associated with chronic ischaemia. To date, there has been no effective treatment for the histological and functional changes of the bladder caused by bladder ischaemia. The present study evaluated the feasibility and effectiveness of using bone marrow mesenchymal stem cells in the treatment of chronic ischaemia-induced bladder detrusor dysfunction in an experimental model. Bone marrow mesenchymal stem cells from Sprague-Dawley (SD) rats were injected into the common iliac artery of experimental animals, then bilateral iliac arteries were ligated and doxazosin mesylate was intragastrically administered. Eight weeks later, urodynamic examination and intravesical pressure measurements were performed on experimental animals. Histological changes of the taken bladder from sacrificed SD rats were evaluated by immunohistochemistry and trichrome staining and the images captured were analyzed by a software program. The average intravesical pressure and detrusor contraction power of the ischaemia group was 16.21±5.26 and 17.26±5.72; those of the experimental group were 24.02±10.06 and 25.84±11.99; the average intravesical pressure and detrusor contraction power of the control group was 28.56±4.48 and 29.57±5.01. The average intravesical pressure and detrusor contraction power of the ischaemia group were significantly lower than those of the experimental and control group, while no significant difference was shown between the experimental and control groups. 5-Bromo-2'-deoxyuridine (BrdU) staining for the experimental group was positive. The percentage of the smooth muscle content in

  5. Experimental characterisation and modelling of deformation- induced microstructure in an A6061 aluminium alloy

    NASA Astrophysics Data System (ADS)

    Kreyca, J. F.; Falahati, A.; Kozeschnik, E.

    2016-03-01

    For industry, the mechanical properties of a material in form of flow curves are essential input data for finite element simulations. Current practice is to obtain flow curves experimentally and to apply fitting procedures to obtain constitutive equations that describe the material response to external loading as a function of temperature and strain rate. Unfortunately, the experimental procedure for characterizing flow curves is complex and expensive, which is why the prediction of flow-curves by computer modelling becomes increasingly important. In the present work, we introduce a state parameter based model that is capable of predicting the flow curves of an A6061 aluminium alloy in different heat-treatment conditions. The model is implemented in the thermo-kinetic software package MatCalc and takes into account precipitation kinetics, subgrain formation, dynamic recovery by spontaneous annihilation and dislocation climb. To validate the simulation results, a series of compression tests is performed on the thermo-mechanical simulator Gleeble 1500.

  6. Histopathological and immunohistochemical study of the hepatic lesions experimentally induced by Entamoeba dispar

    PubMed Central

    Costa, C.A.X.; Brito, K.N.O.; Gomes, M.A.; Caliari, M.V.

    2010-01-01

    The sequence of hepatic necrotic-inflammatory events produced by Entamoeba dispar are originally described in this work. For the first time the experimental lesions produced by E. dispar were described in details, as well as the distribution of the trophozoites detected by the immunohistochemistry. Animals experimentally infected with E. dispar presented necrosis, thrombosis and chronic granulomatous inflammation. Immunoreactive products derived from trofozoites were observed close or associated with trophozoites, epithelioid cells, leucocytes and hepatocytes. Few are the articles on the literature about virulence of E. dispar, which is approximately 9 times more frequent than to Entamoeba histolytica (E. histolytica). Variation in the virulence is therefore expected and signalizing the need of the continuity of studies with E. dispar strains from different places in the world. Taking into account that E. dispar is a closely related species to E. histolytica, these studies could determine new elements involved with E. histolytica pathogenesis, helping us to better understand the disease. PMID:20819776

  7. Experimental pathophysiology of systemic alterations induced by Bothrops asper snake venom.

    PubMed

    Gutiérrez, José María; Escalante, Teresa; Rucavado, Alexandra

    2009-12-01

    Moderate and severe envenomations by the snake Bothrops asper provoke systemic alterations, such as systemic bleeding, coagulopathy, hypovolemia, hemodynamic instability and shock, and acute renal failure. Systemic hemorrhage is a typical finding of these envenomations, and is primarily caused by the action of P-III snake venom metalloproteinases (SVMPs). This venom also contains a thrombin-like serine proteinase and a prothrombin-activating P-III SVMP, both of which cause defibrin(ogen)ation. Thrombocytopenia, predominantly induced by a C-type lectin-like protein, and platelet hypoaggregation, caused by the two defibrin(ogen)ating enzymes, also contribute to hemostatic disturbances, which potentiate the systemic bleeding induced by hemorrhagic SVMPs. Cardiovascular disturbances leading to shock are due to the combined effects of hemorrhagic toxins, other venom components that increase vascular permeability, the action of hypotensive agents in the venom and of endogenous mediators, and the potential cardiotoxic effect of some toxins. Renal alterations are likely to be caused by direct cytotoxicity of venom components in the kidney, and by renal ischemia resultant from hypovolemia and hypoperfusion. Lethality induced by B. asper venom is the consequence of several combined effects among which the action of P-III SVMPs is especially relevant. PMID:19303034

  8. Inhibition of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) reverses experimental pulmonary hypertension.

    PubMed

    Hameed, Abdul G; Arnold, Nadine D; Chamberlain, Janet; Pickworth, Josephine A; Paiva, Claudia; Dawson, Sarah; Cross, Simon; Long, Lu; Zhao, Lan; Morrell, Nicholas W; Crossman, David C; Newman, Christopher M H; Kiely, David G; Francis, Sheila E; Lawrie, Allan

    2012-10-22

    Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by the progressive narrowing and occlusion of small pulmonary arteries. Current therapies fail to fully reverse this vascular remodeling. Identifying key pathways in disease pathogenesis is therefore required for the development of new-targeted therapeutics. We have previously reported tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) immunoreactivity within pulmonary vascular lesions from patients with idiopathic PAH and animal models. Because TRAIL can induce both endothelial cell apoptosis and smooth muscle cell proliferation in the systemic circulation, we hypothesized that TRAIL is an important mediator in the pathogenesis of PAH. We demonstrate for the first time that TRAIL is a potent stimulus for pulmonary vascular remodeling in human cells and rodent models. Furthermore, antibody blockade or genetic deletion of TRAIL prevents the development of PAH in three independent rodent models. Finally, anti-TRAIL antibody treatment of rodents with established PAH reverses pulmonary vascular remodeling by reducing proliferation and inducing apoptosis, improves hemodynamic indices, and significantly increases survival. These preclinical investigations are the first to demonstrate the importance of TRAIL in PAH pathogenesis and highlight its potential as a novel therapeutic target to direct future translational therapies. PMID:23071256

  9. Inhibition of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) reverses experimental pulmonary hypertension

    PubMed Central

    Hameed, Abdul G.; Arnold, Nadine D.; Chamberlain, Janet; Pickworth, Josephine A.; Paiva, Claudia; Dawson, Sarah; Cross, Simon; Long, Lu; Zhao, Lan; Morrell, Nicholas W.; Crossman, David C.; Newman, Christopher M.H.; Kiely, David G.; Francis, Sheila E.

    2012-01-01

    Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by the progressive narrowing and occlusion of small pulmonary arteries. Current therapies fail to fully reverse this vascular remodeling. Identifying key pathways in disease pathogenesis is therefore required for the development of new-targeted therapeutics. We have previously reported tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) immunoreactivity within pulmonary vascular lesions from patients with idiopathic PAH and animal models. Because TRAIL can induce both endothelial cell apoptosis and smooth muscle cell proliferation in the systemic circulation, we hypothesized that TRAIL is an important mediator in the pathogenesis of PAH. We demonstrate for the first time that TRAIL is a potent stimulus for pulmonary vascular remodeling in human cells and rodent models. Furthermore, antibody blockade or genetic deletion of TRAIL prevents the development of PAH in three independent rodent models. Finally, anti-TRAIL antibody treatment of rodents with established PAH reverses pulmonary vascular remodeling by reducing proliferation and inducing apoptosis, improves hemodynamic indices, and significantly increases survival. These preclinical investigations are the first to demonstrate the importance of TRAIL in PAH pathogenesis and highlight its potential as a novel therapeutic target to direct future translational therapies. PMID:23071256

  10. Experimental determination of the relationship between permeability and microfracture-induced damage in bedded salt

    SciTech Connect

    Pfeifle, T.W.

    1998-03-01

    The development of deep underground structures (e.g., shafts, mines, storage and disposal caverns) significantly alters the stress state in the rock near the structure or opening. The effect of such an opening is to concentrate the far-field stress near the free surface. For soft rock such as salt, the concentrating effect of the opening induces deviatoric stresses in the salt that may be large enough to initiate microcracks which then propagate with time. The volume of rock susceptible to damage by microfracturing is often referred to as the disturbed rock zone and, by its nature, is expected to exhibit high permeability relative to that of the native, far-field rock. This paper presents laboratory data that characterize microfracture-induced damage and the effect this damage has on permeability for bedded salt from the Waste Isolation Pilot Plant located in southeastern New Mexico. Damage is induced in the salt through a series of tertiary creep experiments and quantified in terms of dilatant volumetric strain. The permeability of damaged specimens is then measured using nitrogen gas as the permeant. The range in damage investigated included dilatant volumetric strains from less than 0.03 percent to nearly 4.0 percent. Permeability values corresponding to these damage levels ranged from 1 {times} 10{sup {minus}18} m{sup 2} to 1 {times} 10{sup {minus}12} m{sup 2}. Two simple models were fitted to the data for use in predicting permeability from dilatant volumetric strain.

  11. Sn-protoporphyrin suppresses chemically induced experimental hepatic porphyria. Potential clinical implications.

    PubMed Central

    Galbraith, R A; Drummond, G S; Kappas, A

    1985-01-01

    The ability of Sn(tin)-protoporphyrin to inhibit the induction of hepatic delta-aminolevulinate (ALA) synthase by allylisopropyl acetamide (AIA) was examined in the adult rat. Doses of Sn-protoporphyrin of 1, 10, and 50 mumol/kg body wt resulted in decreases in AIA-induced hepatic ALA-synthase activity of 32, 52, and 60%, respectively, compared with rats treated with AIA alone; inhibition of ALA-synthase was not a direct effect of Sn-protoporphyrin. This inhibition of the enzyme activity in liver was reflected in concurrent decreases in urinary excretion of ALA and porphobilinogen (PBG). The increased urinary excretion of ALA and PBG observed following AIA treatment was reduced by the lowest dose of Sn-protoporphyrin (1 mumol/kg body wt) and abolished completely by the higher doses of the metalloporphyrin (10 and 50 mumol/kg body wt). These findings in a rat model of hepatic porphyria suggest that Sn-protoporphyrin may be useful in the treatment of acute exacerbations of "inducible" hepatic porphyrias in man, especially since Sn-protoporphyrin, unlike hematin which is presently used for this purpose, is neither degraded by nor induces the activity of heme oxygenase. PMID:4077989

  12. SPATIAL MEMORY IMPAIRMENT AND HIPPOCAMPAL CELL LOSS INDUCED BY OKADAIC ACID (EXPERIMENTAL STUDY).

    PubMed

    Chighladze, M; Dashniani, M; Beselia, G; Kruashvili, L; Naneishvili, T

    2016-01-01

    In the present study, we evaluated and compared effect of intracerebroventricular (ICV) and intrahippocampal bilateral microinjection of okadaic acid (OA) on spatial memory function assessed in one day water maze paradigm and hippocampal structure in rats. Rats were divided in following groups: Control(icv) - rats injected with ICV and aCSF; Control(hipp) - rats injected intrahippocampally with aCSF; OAicv - rats injected with ICV and OA; OAhipp - rats injected intrahippocampally with OA. Nissl staining of hippocampal sections showed that the pyramidal cell loss in OAhipp group is significantly higher than that in the OAicv. The results of behavioral experiments showed that ICV or intrahippocampal bilateral microinjection of OA did not affect learning process and short-term spatial memory but induced impairment in spatial long-term memory assessed in probe test performance 24 h after training. OA-induced spatial memory impairment may be attributed to the hippocampal cell death. Based on these results OA induced memory deficit and hippocampal cell loss in rat may be considered as a potential animal model for preclinical evaluation of antidementic drug activity. PMID:26870981

  13. Protective effect of nutmeg aqueous extract against experimentally-induced hepatotoxicity and oxidative stress in rats

    PubMed Central

    Kareem, Mohammed Abdul; Gadhamsetty, Saayi Krushna; Shaik, Althaf Hussain; Prasad, E. Maruthi; Kodidhela, Lakshmi Devi

    2013-01-01

    Background: Nutmeg a well-known spice used as a folk medicine in India to treat stomach ailments. Worldwide it is commonly used for food preservation and fragrance. Abundant references were given for nutmeg in ayurveda, unani, and siddha as a single drug or as an important constituent in formulations. Objective: In the present study, nutmeg aqueous extract (NMAET) was evaluated against isoproterenol (ISO)-induced hepatotoxicity and oxidative stress. Materials and Methods: Antioxidant enzymes, liver functions tests, and lipid profile tests were performed using standard procedures. Histological examination of liver was done by fixing in formaldehyde solution and hematoxylin staining. Results: Oral administration of NMAET effectively inhibited the ISO-induced changes in the activities of hepatic marker and antioxidant enzymes in plasma and heart tissue along with lipid peroxidation levels. The liver sections of ISO administered rats showed massive fatty changes, necrosis, ballooning degeneration, and broad infiltration of the lymphocytes and the loss of cellular boundaries; these changes were completely absent in groups treated with extract. Analysis of variance and Duncan's Multiple Range tests were used to perform statistical analysis. Conclusion: Results suggest that the NMAET possess significant potential as hepatoprotective and antioxidative agent against ISO-induced damage in rats. PMID:24459388

  14. Toxoplasma gondii infection can induce retinal DNA damage: an experimental study

    PubMed Central

    El-Sayed, Nagwa Mostafa; Aly, Eman Mohamed

    2014-01-01

    AIM To detect whether Toxoplasma gondii (T. gondii) infection of mice can induce retinal DNA damage. METHODS A total of 20 laboratory-bred male Swiss albino mice were used and divided into four groups: control group (non-infected animals); T. gondii infected group; immunosuppressed infected group; and infected group treated with sulfadiazine and pyrimethamine. Mice eyes were collected 6wk post infection and retinas were obtained. Each retina was immediately processed for comet assay and the frequency of tailed nuclei (DNA damage) was calculated. In addition, retinal DNA damage was revealed by various comet assay parameters that were provided by the image analysis software including tail length, percentage of DNA in the tail, percentage of tailed cells and tail moment. RESULTS The obtained results showed that T. gondii infection induced a statistically significant increase in the frequency of tailed nuclei, tail length, percentage of DNA in the tail, and tail moment in mice retinal cells compared to the control group (which showed some degree of DNA damage). In immunosuppressed infected group, retinal DNA damage was severing and there was significant increase in various comet assay parameters compared to both control and infected groups. After treatment with sulfadiazine and pyrimethamine, retinal DNA damage decreased and all comet assay parameters showed a statistical significant decrease compared to infected groups. CONCLUSION T. gondii infection can induce DNA damage in mice retinal cells. PMID:24967186

  15. Evaluation of the antipsychotic potential of Panax quinquefolium in ketamine induced experimental psychosis model in mice.

    PubMed

    Chatterjee, Manavi; Singh, Seema; Kumari, Reena; Verma, Anil Kumar; Palit, Gautam

    2012-04-01

    The search for novel pharmacotherapy from medicinal plants for psychiatric illnesses has progressed significantly from the past few decades and their therapeutic potential has been assessed in a variety of animal models. The aim of our study was to screen one such plant, Panax quinquefolium (PQ), with significant neuroactive properties for its antipsychotic potential. A graded dose study with PQ at 12.5-200 mg/kg, p. o. showed differential effects against the ketamine induced hyperactivity in the Digiscan animal activity monitor. Nevertheless at 100 mg/kg, p.o., PQ blocked ketamine induced memory impairment in the passive avoidance paradigm. In the chronic studies, PQ reduced the ketamine induced enhanced immobility in the forced swim test and did not show extra-pyramidal side effects in bar test and wood block test of catalepsy. These behavioural effects were compared with standard drugs haloperidol and clozapine. Further PQ reduced DA and 5-HT content after chronic treatment, but