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1

Acaricidal Activity of Eugenol Based Compounds against Scabies Mites  

PubMed Central

Backgound Human scabies is a debilitating skin disease caused by the “itch mite” Sarcoptes scabiei. Ordinary scabies is commonly treated with topical creams such as permethrin, while crusted scabies is treated with topical creams in combination with oral ivermectin. Recent reports of acaricide tolerance in scabies endemic communities in Northern Australia have prompted efforts to better understand resistance mechanisms and to identify potential new acaricides. In this study, we screened three essential oils and four pure compounds based on eugenol for acaricidal properties. Methodology/Principal Findings Contact bioassays were performed using live permethrin-sensitive S. scabiei var suis mites harvested from pigs and permethrin-resistant S. scabiei var canis mites harvested from rabbits. Results of bioassays showed that clove oil was highly toxic against scabies mites. Nutmeg oil had moderate toxicity and ylang ylang oil was the least toxic. Eugenol, a major component of clove oil and its analogues –acetyleugenol and isoeugenol, demonstrated levels of toxicity comparable to benzyl benzoate, the positive control acaricide, killing mites within an hour of contact. Conclusions The acaricidal properties demonstrated by eugenol and its analogues show promise as leads for future development of alternative topical acaricides to treat scabies. PMID:20711455

Pasay, Cielo; Mounsey, Kate; Stevenson, Graeme; Davis, Rohan; Arlian, Larry; Morgan, Marjorie; Vyszenski-Moher, DiAnn; Andrews, Kathy; McCarthy, James

2010-01-01

2

Scabies  

MedlinePLUS

... Apply once daily for 5 consecutive days. Precipitated sulfur (5% or 10%) – This is prepared with petroleum ... Scabies. http://www.cdc.gov/scabies/index.html. Modified November 10, 2008. Accessed March 11, 2009. Bolognia, ...

3

Scabies  

MedlinePLUS

... everyone else in the house with the scabies medicine, just in case. To kill all other mites, your parent will use hot, soapy water to wash all clothing, towels, or sheets used by anyone who has scabies. Then the laundry should be dried on high heat. Your parent also can place other ...

4

Scabies  

MedlinePLUS

... frequent skin-to-skin contact between people. Hospitals, child-care centers, and nursing homes are examples. Scabies can easily infect sex partners and other household members. Sharing clothes, towels, ...

5

Scabies.  

PubMed

Scabies is an ectoparasite caused by the mite Sarcoptes scabiei var hominis, an obligate human parasite. There are about 300 million cases of scabies in the world each year. Common predisposing factors are overcrowding, immigration, poor hygiene, poor nutritional status, homelessness, dementia, and sexual contact. Direct skin-to-skin contact between 15 and 20 minutes is needed to transfer the mites from one person to another. The diagnosis suspected with a clinical history of itch, worse at night, affecting other family members, clinical distribution, and appearance. Definite diagnosis relies on microscopic identification of the mites, eggs, or fecal pellets with 10% potassium hydroxide, ink enhancement, tetracycline fluorescence tests, or mineral oil; other methods include: epiluminescence light microscopy and S. scabiei DNA. The most commonly used treatment modalities are permethrin and ivermectin. Persistence of symptoms for 2-6 weeks after successful treatment is common. Most recurrences are because of reinfection from untreated contacts. PMID:19580575

Hicks, Maria I; Elston, Dirk M

2009-01-01

6

Scabies.  

PubMed

Scabies is a neglected parasitic disease that is a major public health problem in many resource-poor regions. It causes substantial morbidity from secondary infections and post-infective complications such as acute post-streptococcal glomerulonephritis. Disease control requires treatment of the affected individual and all people they have been in contact with, but is often hampered by inappropriate or delayed diagnosis, poor treatment compliance, and improper use of topical compounds such as permethrin, lindane, or benzyl benzoate. In addition to concerns over toxicity with such compounds, parasite resistance seems to be increasing. Oral ivermectin is an alternative that has been used successfully in community control programmes. Plant derivatives such as turmeric, neem, and tea tree oil are also promising future treatments. The disease is strongly associated with poverty and overcrowding, and the associated stigma can ostracise affected individuals. Treatment of scabies in poor countries needs to integrate drug treatment programmes with efforts to improve the socioeconomic conditions and education programmes to reduce stigma. We expect the future to bring more sensitive and specific clinical and laboratory-based diagnostic methods, as well as new therapeutic strategies. PMID:16731272

Heukelbach, Jörg; Feldmeier, Hermann

2006-05-27

7

Scabies Diagnosis  

MedlinePLUS

... CDC.gov . Parasites - Scabies Parasites Home Share Compartir Diagnosis Diagnosis of a scabies infestation usually is made based ... and the presence of burrows. Whenever possible, the diagnosis of scabies should be confirmed by identifying the ...

8

Immune-related gene expression in nurse honey bees (Apis mellifera) exposed to synthetic acaricides.  

PubMed

The mite Varroa destructor is an ectoparasite affecting honey bees worldwide. Synthetic acaricides have been among the principal tools available to beekeepers for its control, although several studies have shown its negative effects on honey bee physiology. Recent research suggests that those molecules strongly impact on immune signaling cascades and cellular immunity. In the present work, LC(50) in six-day-old bees were determined for the following acaricides: tau-fluvalinate, flumethrin, amitraz and coumaphos. According to this obtained value, a group of individuals was treated with each acaricide and then processed for qPCR analysis. Transcript levels for genes encoding antimicrobial peptides and immune-related proteins were assessed. Flumethrin increased the expression of hymenoptaecin when comparing treated and control bees. Significant differences were recorded between coumaphos and flumethrin treatments, while the first one reduced the expression of hymenoptaecin and abaecin, the last one up-regulated their expressions. No significant statistically changes were recorded in the expression levels of vitellogenin, lysozyme or glucose dehydrogenase among bees treated with acaricides and control bees. This work constitutes the first report, under laboratory conditions, about induction of immune related genes in response to synthetic miticides. PMID:23147024

Garrido, Paula Melisa; Antúnez, Karina; Martín, Mariana; Porrini, Martín Pablo; Zunino, Pablo; Eguaras, Martín Javier

2013-01-01

9

Occupational scabies.  

PubMed Central

A localised epidemic of scabies lasting nearly a year occurred among crews on river pleasure craft. There was a sharp contrast between the paucity of scabietic lesions, especially burrows, and an unusually high infectivity. Scarcely a crew member was free from itching, yet individually diagnosis proved extremely difficult. PMID:871872

Rycroft, R J; Calnan, C D

1977-01-01

10

Scabies mite, photomicrograph (image)  

MedlinePLUS

... of the scabies mite. They burrows into the skin, depositing both eggs and feces. A scabies infestation causes intense itching (pruritus) which leads to scratching and damage of the skin (excoriation). If left untreated, the infestation may last ...

11

Scabies: Prevention and Control  

MedlinePLUS

... gov . Parasites - Scabies Parasites Home Share Compartir Prevention & Control When a person is infested with scabies mites ... avoid outbreaks. Institutional outbreaks can be difficult to control and require a rapid, aggressive, and sustained response. ...

12

Scabies (For Parents)  

MedlinePLUS

... ON THIS TOPIC Skin, Hair, and Nails Impetigo Tinea (Ringworm, Jock Itch, Athlete's Foot) Impetigo Scabies Skin Biopsy Impetigo Scabies Ringworm Hygiene Basics Contact Us Print Additional resources Send ...

13

Treatment of scabies infestations.  

PubMed

Scabies is an intensely pruritic disorder induced by an immune allergic response to infestation of the skin by the mite Sarcoptes scabiei. The biology of the mite, the clinical aspects and diagnosis of scabies infestations as well as the treatment of choice with 5% permethrin dermal cream and the use of scabicides based on other chemical substances are reviewed. PMID:18814689

Mumcuoglu, K Y; Gilead, L

2008-09-01

14

Scabies: Frequently Asked Questions (FAQs)  

MedlinePLUS

... to treat crusted scabies successfully. Reinfestation from items (fomites) such as clothing, bedding, or towels that were ... by persons with crusted scabies); potentially contaminated items (fomites) should be machine washed in hot water and ...

15

The scourge of scabies.  

PubMed

Scabies ('Itch Mite') is truly a Great Neglected Disease that inflicts misery on millions. Molecular approaches, while still in their infancy, are providing a better understanding of the parasite and will have important implications for control and prevention. It has long been thought that dogs may act as a reservoir for human infections. However, genetic studies cast doubt over this supposition. PMID:11852281

Kemp, David J; Walton, Shelley F; Harumal, Pearly; Currie, Bart J

2002-02-01

16

[Bullous scabies and scabies-triggered bullous pemphigoid].  

PubMed

Two patients were admitted to our hospital with tense blisters on an erythematous base, typical for bullous pemphigoid. In both patients an infestation with Sarcoptes scabiei was diagnosed by dermatoscopy as well as histological examination. In one patient the clinical diagnosis of bullous pemphigoid could be confirmed by immunofluorescence microscopy, histopathology and a clinical relapse of bullous pemphigoid without scabies infestation. In the other patient no evidence for an autoantibody-mediated autoimmune blistering disease was found. We postulate that bullous scabies could develop after long persistency of the parasites leading to a specific immune response with activation of T helper type 2 (Th2) cells causing high levels of the cytokine interleukin 5 and then consecutively eosinophilia. Secretion of proteolytic enzymes near the basal membrane zone might explain the development of intraepidermal, often suprabasal blisters. In contrast, in the first patient the scabies infestation might have triggered a flare up of the underlying autoimmune disease. Comparison of our two patients demonstrates two entities: bullous pemphigoid triggered by scabies as a Koebner phenomenon and a bullous subtype of scabies mimicking bullous pemphigoid. Therefore both, scabies infestation triggering bullous pemphigoid and bullous pemphigoid-like scabies should be included in the differential diagnosis of vesicles, tense blisters and erythema, especially at an early clinical stage. PMID:11220241

Bornhövd, E; Partscht, K; Flaig, M J; Messer, G

2001-01-01

17

Permethrin for scabies in children  

PubMed Central

ABSTRACT QUESTION I frequently see children with scabies in my practice. A variety of medications are available to treat scabies. Permethrin is one of the most common medications used. Is permethrin a safe and effective option for children? ANSWER Scabies is a common parasitic skin infection. It is highly prevalent in young children. Topical permethrin (5% cream) is a safe and effective scabicide in children. It is recommended as a first-line therapy for patients older than 2 months of age. Because there are theoretical concerns regarding percutaneous absorption of permethrin in infants younger than 2 months of age, guidelines recommend 7% sulfur preparation instead of permethrin. PMID:20944041

Albakri, Lina; Goldman, Ran D.

2010-01-01

18

Scabies Mites Alter the Skin Microbiome and Promote Growth of Opportunistic Pathogens in a Porcine Model  

PubMed Central

Background The resident skin microbiota plays an important role in restricting pathogenic bacteria, thereby protecting the host. Scabies mites (Sarcoptes scabiei) are thought to promote bacterial infections by breaching the skin barrier and excreting molecules that inhibit host innate immune responses. Epidemiological studies in humans confirm increased incidence of impetigo, generally caused by Staphylococcus aureus and Streptococcus pyogenes, secondary to the epidermal infestation with the parasitic mite. It is therefore possible that mite infestation could alter the healthy skin microbiota making way for the opportunistic pathogens. A longitudinal study to test this hypothesis in humans is near impossible due to ethical reasons. In a porcine model we generated scabies infestations closely resembling the disease manifestation in humans and investigated the scabies associated changes in the skin microbiota over the course of a mite infestation. Methodology/Principal Findings In a 21 week trial, skin scrapings were collected from pigs infected with S. scabies var. suis and scabies-free control animals. A total of 96 skin scrapings were collected before, during infection and after acaricide treatment, and analyzed by bacterial 16S rDNA tag-encoded FLX-titanium amplicon pyrosequencing. We found significant changes in the epidermal microbiota, in particular a dramatic increase in Staphylococcus correlating with the onset of mite infestation in animals challenged with scabies mites. This increase persisted beyond treatment from mite infection and healing of skin. Furthermore, the staphylococci population shifted from the commensal S. hominis on the healthy skin prior to scabies mite challenge to S. chromogenes, which is increasingly recognized as being pathogenic, coinciding with scabies infection in pigs. In contrast, all animals in the scabies-free cohort remained relatively free of Staphylococcus throughout the trial. Conclusions/Significance This is the first experimental in vivo evidence supporting previous assumptions that establishment of pathogens follow scabies infection. Our findings provide an explanation for a biologically important aspect of the disease pathogenesis. The methods developed from this pig trial will serve as a guide to analyze human clinical samples. Studies building on this will offer implications for development of novel intervention strategies against the mites and the secondary infections. PMID:24875186

Swe, Pearl M.; Zakrzewski, Martha; Kelly, Andrew; Krause, Lutz; Fischer, Katja

2014-01-01

19

Complement Inhibitors from Scabies Mites Promote Streptococcal Growth – A Novel Mechanism in Infected Epidermis?  

PubMed Central

Background Scabies is highly prevalent in socially disadvantaged communities such as indigenous populations and in developing countries. Generalized itching causes discomfort to the patient; however, serious complications can occur as a result of secondary bacterial pyoderma, commonly caused by Streptococcus pyogenes (GAS) or Staphylococcus aureus. In the tropics, skin damage due to scabies mite infestations has been postulated to be an important link in the pathogenesis of disease associated with acute rheumatic fever and heart disease, poststreptococcal glomerulonephritis and systemic sepsis. Treatment of scabies decreases the prevalence of infections by bacteria. This study aims to identify the molecular mechanisms underlying the link between scabies and GAS infections. Methodology/Principal Findings GAS bacteria were pre-incubated with blood containing active complement, phagocytes and antibodies against the bacteria, and subsequently tested for viability by plate counts. Initial experiments were done with serum from an individual previously exposed to GAS with naturally acquired anti-GAS antibodies. The protocol was optimized for large-scale testing of low-opsonic whole blood from non-exposed human donors by supplementing with a standard dose of heat inactivated human sera previously exposed to GAS. This allowed an extension of the dataset to two additional donors and four proteins tested at a range of concentrations. Shown first is the effect of scabies mite complement inhibitors on human complement using ELISA-based complement activation assays. Six purified recombinant mite proteins tested at a concentration of 50 µg/ml blocked all three complement activation pathways. Further we demonstrate in human whole blood assays that each of four scabies mite complement inhibitors tested increased GAS survival rates by 2–15 fold. Conclusions/Significance We propose that local complement inhibition plays an important role in the development of pyoderma in scabies infested skin. This molecular link between scabies and bacterial infections may provide new avenues to develop alternative treatment options against this neglected disease. PMID:22815998

Mika, Angela; Reynolds, Simone L.; Pickering, Darren; McMillan, David; Sriprakash, Kadaba S.; Kemp, David J.; Fischer, Katja

2012-01-01

20

Policy Decisions in Scabies Control.  

ERIC Educational Resources Information Center

In a Kansas elementary school, an outbreak of scabies was discovered by the school nurse. Through cooperative planning with the local health department, the infected children were excluded from school pending medical treatment, and a screening program was set up for the entire student population. (JN)

Foutes, James A.; And Others

1981-01-01

21

Norwegian crusted scabies: an unusual case presentation.  

PubMed

Scabies is a contagious condition that is transmitted through direct contact with an infected person and has been frequently associated with institutional and healthcare-facility outbreaks. The subtype Norwegian crusted scabies can masquerade as other dermatologic diseases owing to the heavy plaque formation. Successful treatment has been documented in published reports, including oral ivermectin and topical permethrin. Few case studies documenting the treatment of Norwegian crusted scabies have reported the use of surgical debridement as an aid to topical and/or oral treatment when severe plaque formation has been noted. A nursing home patient was admitted to the hospital for severe plaque formation of both feet. A superficial biopsy was negative for both fungus and scabies because of the severity of the plaque formation on both feet. The patient underwent a surgical, diagnostic biopsy of both feet, leading to the diagnosis of Norwegian crusted scabies. A second surgical debridement was then performed to remove the extensive plaque formation and aid the oral ivermectin and topical permethrin treatment. The patient subsequently made a full recovery and was discharged back to the nursing home. At 2 and 6 months after treatment, the patient remained free of scabies infestation, and the surgical wound had healed uneventfully. The present case presentation has demonstrated that surgical debridement can be complementary to the standard topical and oral medications in the treatment of those with Norwegian crusted scabies infestation. PMID:24370484

Maghrabi, Michael M; Lum, Shireen; Joba, Ameha T; Meier, Molly J; Holmbeck, Ryan J; Kennedy, Kate

2014-01-01

22

Scabies and bedbugs in hospital outbreaks.  

PubMed

Scabies and bedbugs are two emerging ectoparasitic infections reported in crowded areas, including hospitals. Skin involvement is the main presenting initial manifestation for both infections, and the diagnosis is yet challenging for both. Topical permethrin is considered the first-line therapy for scabies except for crusted scabies which is mainly treated with oral ivermectin. To the contrary, treatment of bedbugs is mainly symptomatic. Avoiding close contact, early diagnosis and treatment of infected persons as well as decontamination of the involved environment play an essential role in controlling outbreaks in healthcare settings. PMID:24897948

Sfeir, Maroun; Munoz-Price, L Silvia

2014-08-01

23

Atypical scabies presenting as annular patches.  

PubMed

Scabies is a common parasitic disease that can be recognized by the development of itchy lesions and a predilection for certain places on the body. It may infrequently present with patchy lesions. We report a patient with well-defined annular patches. Histopathology showed an egg of the scabies mite in the epidermis. Treatment with permethrin cream resulted in complete resolution of her disease. PMID:22967356

Hossain, Delwar

2014-01-01

24

Atypical Presentation of Scabies Among Nursing Home Residents  

Microsoft Academic Search

Background. Scabies epidemics are not uncommon in nursing homes. Effective treatment is enhanced by prompt clinical diagnosis and early intervention. The clinical presentation of scabies may vary in older, immunocompromised or cognitively impaired persons. Methods. We performed a retrospective study of all residents diagnosed with scabies in a multilevel long-term care geriatric facility. The duration of the outbreak was from

Margaret-Mary G. Wilson; Carolyn D. Philpott; Wayne A. Breer

2001-01-01

25

[Report on erythroderma and scabies infection in connection with two cases of scabies norvegica].  

PubMed

Erythroderma is an inflammation of almost the whole surface of the skin, characterized by erythema, skin infiltration and desquamation. Despite the etiological factors, the generalized inflammation of a large body surface can lead to a life-threatening condition in itself. Parasite infection lies rarely in the background of erythroderma. The Sarcoptes scabiei var. hominis belonging to the mite family is the cause of scabies disease. While the prevalence of "classic" scabies is high world-wide, the more severe and more dangerous form - scabies norvegica - is only seldom observed. Diagnosis and treatment is highly important from an epidemiological aspect. The authors discuss the differential diagnostic problems and epidemiological significance of scabies infection and erythroderma using two cases. PMID:19004745

Jenei, Márta; Veres, Imre; Schmidt, Emese; Varga, Imre; Remenyik, Eva

2008-11-23

26

Scabies: more than just an irritation.  

PubMed

Human scabies, caused by skin infestation with the arthropod mite, Sarcoptes scabiei, typically results in a papular, intensely pruritic eruption involving the interdigital spaces, and flexure creases. Recent research has led to a reassessment of the morbidity attributable to this parasite in endemic communities, particularly resulting from secondary skin sepsis and postinfective complications including glomerulonephritis. This has led to studies of the benefits of community based control programmes, and to concerns regarding the emergence of drug resistance when such strategies are employed. The renewed research interest into the biology of this infection has resulted in the application of molecular tools. This has established that canine and human scabies populations are genetically distinct, a finding with major implications for the formulation of public health control policies. Further research is needed to increase understanding of drug resistance, and to identify new drug targets and potential vaccine candidates. PMID:15254301

McCarthy, J S; Kemp, D J; Walton, S F; Currie, B J

2004-07-01

27

[Approach to the patient with scabies].  

PubMed

Scabies is an ectoparasitosis caused by Sarcoptes scabiei. Clinical types can be highly variable. There might be a problem in diagnosis due to difficulty in detecting the parasite and atypical clinical features. Delayed diagnosis may be the cause of outbreaks for people living in overcrowded places such as poorhouses, orphanages and barracks. The different types of treatment have been discussed as well as rules for prevention. PMID:17106863

Unver, Ay?egül Yolasi?maz; Turgay, Nevin

2006-01-01

28

Scabies: new future for a neglected disease.  

PubMed

Scabies is a disease of global proportions in both human and animal populations, resulting from infestation of the skin with the "itch" mite Sarcoptes scabiei. Despite the availability of effective chemotherapy the intensely itching lesions engender significant morbidity primarily due to secondary sepsis and post-infective complications. Some patients experience an extreme form of the disease, crusted scabies, in which many hundreds of mites may infest the skin causin severe crusting and hyperkeratosis. Overcrowded living conditions and poverty have been identified as significant confounding factors in transmission of the mite in humans. Control is hindered by difficulties with diagnosis, the cost of treatment, evidence for emerging resistance and lack of effective vaccines. Historically research on scabies has been extremely limited because of the difficulty in obtaining sufficient quantities of the organism. Recent molecular approaches have enabled considerable advances in the study of population genetics and transmission dynamics of S. scabiei. However, the most exciting and promising development is the potential exploitation of newly available data from S. scabiei cDNA libraries and EST projects. Ultimately this knowledge may aid early identification of disease, novel forms of chemotherapy, vaccine development and new treatment possibilities for this important but neglected parasite. PMID:15504541

Walton, Shelley F; Holt, Deborah C; Currie, Bart J; Kemp, David J

2004-01-01

29

Efficacy and application considerations of selected residual acaricides against the mold mite Tyrophagus putrescentiae (Acari: Acaridae) in simulated retail habitats.  

PubMed

The mold mite, Tyrophagus putrescentiae (Schrank), is a stored product pest of economic significance that commonly infests many types of food and animal feed products. There is limited information regarding pest management tactics, including residual acaricides for managing this pest in retail store habitats. The purpose of this study was to assess the potential of commercially available acaricides that could provide a protective barrier near susceptible food packages destined for consumer use. Mite mortality at 24 and 48 h was measured after exposing mites to acaricide residues applied to a nonporous surface. Two additional factors included in the study were humidity and the presence of an adjuvant to facilitate spread of acaricide on nonporous surfaces. Increasing humidity levels generally decreased acaricide efficacy. Use of the adjuvant itself did not appear to affect efficacy, but the type of application (wet or slurry, or dry) of dust acaricides significantly affected efficacy. The potential for residual acaricides to act as a barrier (within 24-48 h) against dispersal of this mite was discussed. PMID:24020311

Freitag, Jessica A; Kells, Stephen A

2013-08-01

30

Scratching the itch: management of scabies in A&E.  

PubMed

Epidemics of scabies seem to occur in 20-25-year cycles. One of the resultant problems is that few A&E nurses practice through more than one epidemic and with each new outbreak of scabies, the latest generation of A&E nurses have to learn how to recognize and manage the disease. This article describes scabies, how to recognize it and the treatment options available. Although uncertainty remains, Permethrin is the first treatment of choice and should be used in the 5% cream form, not the 100% lotion. Crusted Norwegian scabies requires prompt and careful attention along with Specialist advice. The challenge for A&E staff is to recognize scabies, treat it appropriately and to help educate those most at risk. PMID:11760327

Hadfield-Law, L

2000-10-01

31

Detection of scabies: A systematic review of diagnostic methods  

PubMed Central

BACKGROUND: Accurate diagnosis of scabies infection is important for patient treatment and for public health control of scabies epidemics. OBJECTIVE: To systematically review the accuracy and precision of history, physical examination and tests for diagnosing scabies. METHODS: Using a structured search strategy, Medline and Embase databases were searched for English and French language articles that included a diagnosis of scabies. Studies comparing history, physical examination and/or any diagnostic tests with the reference standard of microscopic visualization of mites, eggs or fecal elements obtained from skin scrapings or biopsies were included for analysis. Data were extracted using standard criteria. RESULTS: History and examination of pruritic dermatoses failed to accurately diagnose scabies infection. Dermatoscopy by a trained practitioner has a positive likelihood ratio of 6.5 (95% CI 4.1 to 10.3) and a negative likelihood ratio of 0.1 (95% CI 0.06 to 0.2) for diagnosing scabies. The accuracy of other diagnostic tests could not be calculated from the data in the literature. CONCLUSIONS: In the face of such diagnostic inaccuracy, clinical judgment is still practical in diagnosing scabies. Two tests are used – the burrow ink test and handheld dermatoscopy. The burrow ink test is a simple, rapid, noninvasive test that can be used to screen a large number of patients. Handheld dermatoscopy is an accurate test, but requires special equipment and trained practitioners. Given the morbidity and costs of scabies infection, and that studies to date lack adequate internal and external validity, research to identify or develop accurate diagnostic tests for scabies infection is needed and justifiable. PMID:23205026

Leung, Victor; Miller, Mark

2011-01-01

32

Scratching the itch: new tools to advance understanding of scabies.  

PubMed

Scabies remains a significant public health problem worldwide. Research into aspects of Sarcoptes scabiei biology and host-parasite interactions has been impeded by an inability to maintain mites in vitro and by limited access to parasite material and infected subjects. The generation of comprehensive expressed sequence tag libraries has enabled the initial characterisation of molecules of interest to diagnostics, vaccines, and drug resistance. The recent development and utilisation of animal models, combined with next-generation technologies, is anticipated to lead to new strategies to prevent, diagnose, and treat scabies, ultimately improving skin health in both human and veterinary settings. This article will summarise recent molecular and immunologic advances on scabies, and will address priorities for the exciting 'next chapter' of scabies research. PMID:23088958

Mounsey, Kate E; McCarthy, James S; Walton, Shelley F

2013-01-01

33

Scabies: important clinical consequences explained by new molecular studies.  

PubMed

In 2004, we reviewed the status of disease caused by the scabies mite Sarcoptes scabiei at the time and pointed out that very little basic research had ever been done. The reason for this was largely the lack of availability of mites for experimental purposes and, to a degree, a consequent lack of understanding of its importance, resulting in the trivial name 'itch mite'. Scabies is responsible for major morbidity in disadvantaged communities and immunocompromised patients worldwide. In addition to the physical discomfort caused by the disease, scabies infestations facilitate infection by bacterial pathogens such as Streptococcus pyogenes and Staphylococcus aureus via skin lesions, resulting in severe downstream disease such as in a high prevalence of rheumatic fever/heart disease in affected communities. We now have further evidence that in disadvantaged populations living in tropical climates, scabies rather than 'Strep throat' is an important source of S. pyogenes causing rheumatic fever and eventually rheumatic heart disease. In addition, our work has resulted in two fundamental research tools that facilitate much of the current biomedical research efforts on scabies, namely a public database containing ~45,000 scabies mite expressed sequence tags and a porcine in vivo model. Here we will discuss novel and unexpected proteins encountered in the database that appear crucial to mite survival with regard to digestion and evasion of host defence. The mode(s) of action of some of these have been at least partially revealed. Further, newly discovered molecules that may well have a similar role, such as a family of inactivated cysteine proteases, are yet to be investigated. Hence, there are now whole families of potential targets for chemical inhibitors of S. scabiei. These efforts put today's scabies research in a unique position to design and test small molecules that may specifically interfere with mite-derived molecules, such as digestive proteases and mite complement inhibitors. The porcine scabies model will be available to trial in vivo treatment with potential inhibitors. New therapies for scabies may be developed from these studies and may contribute to reduce the spread of scabies and the subsequent prevalence of bacterial skin infections and their devastating sequelae in the community. PMID:22726646

Fischer, Katja; Holt, Deborah; Currie, Bart; Kemp, David

2012-01-01

34

Opportunities to investigate the effects of ivermectin mass drug administration on scabies.  

PubMed

The recent article by Mohammed et al. demonstrates an impressive effect of ivermectin mass drug administration for lymphatic filariasis on the burden of scabies. Partnering scabies research within the evaluation and monitoring of Neglected Tropical Disease programmes could potentially increase our understanding of the epidemiology and control of scabies and its important bacterial complications. PMID:23594459

Engelman, Daniel; Martin, Diana L; Hay, Roderick J; Chosidow, Olivier; McCarthy, James S; Fuller, L Claire; Steer, Andrew C

2013-01-01

35

COMMON IN COLLEGE SETTINGS Crabs and scabies are two different types of parasites that  

E-print Network

COMMON IN COLLEGE SETTINGS Crabs and scabies are two different types of parasites that infect intense itching. Crabs and scabies infections are common where people live close together. College living arrangements provide many opportunities for the spread of crabs and scabies. Do not be embarrassed if you

Virginia Tech

36

Streptomyces scabies 87-22 Possesses a Functional Tomatinase?  

PubMed Central

The actinomycete Streptomyces scabies 87-22 is the causal agent of common scab, an economically important disease of potato and taproot crops. Sequencing of the S. scabies 87-22 genome revealed the presence of a gene with high homology to the gene encoding the ?-tomatine-detoxifying enzyme tomatinase found in fungal tomato pathogens. The tomA gene from S. scabies 87-22 was cotranscribed with a putative family 1 glycosyl hydrolase gene, and purified TomA protein was active only on ?-tomatine and not potato glycoalkaloids or xylans. Tomatinase-null mutants were more sensitive to ?-tomatine than the wild-type strain in a disk diffusion assay. Interestingly, tomatine affected only aerial mycelium and not vegetative mycelium, suggesting that the target(s) of ?-tomatine is not present during vegetative growth. Severities of disease for tomato seedlings affected by S. scabies 87-22 wild-type and ?tomA1 strains were indistinguishable, suggesting that tomatinase is not important in pathogenicity on tomato plants. However, conservation of tomA on a pathogenicity island in S. acidiscabies and S. turgidiscabies suggests a role in plant-microbe interaction. PMID:18835993

Seipke, Ryan F.; Loria, Rosemary

2008-01-01

37

Treatment of scabies: Comparison of permethrin 5% versus ivermectin.  

PubMed

Scabies is an ectoparasitic, highly contagious skin disease caused by a mite called Sarcoptes scabiei. The insecticides ivermectin and permethrin are commonly used for treatment of scabies. This study aimed at comparing the efficacy of oral ivermectin with topical permethrin in treating scabies. Two hundred and forty-two patients with scabies attending the dermatology outpatient department of Sina Hospital, Tabriz University of Medical Sciences were admitted. Patients were divided into two groups randomly. The first group and their family contacts received 5% permethrin cream and the other received oral ivermectin. Treatment was evaluated at intervals of 2 and 4 weeks. A single dose of ivermectin provided a cure rate of 85.9% at a 2-week interval, which increased to 100% after crossing over to the permethrin group at a 4-week interval. Twice application of permethrin with a 1-week interval was effective in 92.5% of patients, which increased to 94.2% after crossing over to the ivermectin group at a 4-week interval. Permethrin-treated patients recovered earlier. Twice application of permethrin with a 1-week interval is superior to a single dose of ivermectin. The temporal dissociation in clinical response suggests that ivermectin may not be effective against all the stages in the life cycle of the parasite. PMID:22385121

Goldust, Mohamad; Rezaee, Elham; Hemayat, Sevil

2012-06-01

38

Structural mechanisms of inactivation in scabies mite serine protease paralogues.  

PubMed

The scabies mite (Sarcoptes scabiei) is a parasite responsible for major morbidity in disadvantaged communities and immuno-compromised patients worldwide. In addition to the physical discomfort caused by the disease, scabies infestations facilitate infection by Streptococcal species via skin lesions, resulting in a high prevalence of rheumatic fever/heart disease in affected communities. The scabies mite produces 33 proteins that are closely related to those in the dust mite group 3 allergen and belong to the S1-like protease family (chymotrypsin-like). However, all but one of these molecules contain mutations in the conserved active-site catalytic triad that are predicted to render them catalytically inactive. These molecules are thus termed scabies mite inactivated protease paralogues (SMIPPs). The precise function of SMIPPs is unclear; however, it has been suggested that these proteins might function by binding and protecting target substrates from cleavage by host immune proteases, thus preventing the host from mounting an effective immune challenge. In order to begin to understand the structural basis for SMIPP function, we solved the crystal structures of SMIPP-S-I1 and SMIPP-S-D1 at 1.85 A and 2.0 A resolution, respectively. Both structures adopt the characteristic serine protease fold, albeit with large structural variations over much of the molecule. In both structures, mutations in the catalytic triad together with occlusion of the S1 subsite by a conserved Tyr200 residue is predicted to block substrate ingress. Accordingly, we show that both proteases lack catalytic function. Attempts to restore function (via site-directed mutagenesis of catalytic residues as well as Tyr200) were unsuccessful. Taken together, these data suggest that SMIPPs have lost the ability to bind substrates in a classical "canonical" fashion, and instead have evolved alternative functions in the lifecycle of the scabies mite. PMID:19427318

Fischer, Katja; Langendorf, Christopher G; Irving, James A; Reynolds, Simone; Willis, Charlene; Beckham, Simone; Law, Ruby H P; Yang, Sundy; Bashtannyk-Puhalovich, Tanya A; McGowan, Sheena; Whisstock, James C; Pike, Robert N; Kemp, David J; Buckle, Ashley M

2009-07-24

39

Parasitic scabies mites and associated bacteria joining forces against host complement defence.  

PubMed

Scabies is a ubiquitous and contagious skin disease caused by the parasitic mite Sarcoptes scabiei Epidemiological studies have identified scabies as a causative agent for secondary skin infections caused by Staphylococcus aureus and Streptococcus pyogenes. This is an important notion, as such bacterial infections can lead to serious downstream life-threatening complications. As the complement system is the first line of host defence that confronts invading pathogens, both the mite and bacteria produce a large array of molecules that inhibit the complement cascades. It is hypothesised that scabies mite complement inhibitors may play an important role in providing a favourable micro-environment for the establishment of secondary bacterial infections. This review aims to bring together the current literature on complement inhibition by scabies mites and bacteria associated with scabies and to discuss the proposed molecular link between scabies and bacterial co-infections. PMID:25081184

Swe, P M; Reynolds, S L; Fischer, K

2014-11-01

40

Acaricidal potentials of active properties isolated from Cynanchum paniculatum and acaricidal changes by introducing functional radicals.  

PubMed

This study evaluated the acaricidal activities of acetophenone and its derivatives for their potentials as natural acaricides using an impregnated fumigant bioassay against Dermatophagoides spp. and Tyrophagus putrescentiae . On the basis of the LD50 values against D. farinae, 3'-methoxyacetophenone (0.41 ?g/cm(2)) was 89.9 times more toxic than DEET (36.87 ?g/cm(2)), followed by 4'-methoxyacetophenone (0.52 ?g/cm(2)), 2'-methoxyacetophenone (0.75 ?g/cm(2)), 2'-hydroxy-5'-methoxyacetophenone (1.03 ?g/cm(2)), 2'-hydroxy-4'-methoxyacetophenone (1.29 ?g/cm(2)), acetophenone (1.48 ?g/cm(2)), 2'-hydroxyacetophenone (1.74 ?g/cm(2)), 2',5'-dimethoxyacetophenone (1.87 ?g/cm(2)), 2',4'-dimethoxyacetophenone (2.10 ?g/cm(2)), and benzyl benzoate (9.92 ?g/cm(2)). In regard to structure-activity relationships between acaricidal activity and functional radicals (hydroxyl and methoxy groups) on the acetophenone skeleton, a monomethoxy group (2'-, 3'-, and 4'-methoxyacetone) on the acetophenone skeleton was more toxic than were the other groups (2',4'- and 2',5'-dimethoxyacetophenone, 2'- and 4'-hydroxyacetophenone, 2'-hydroxy-4'-methoxyacetophenone, 2'-hydroxy-5'-methoxyacetophenone, and 4'-hydroxy-3'-methoxyacetophenone). These results indicated that acaricidal activity against three mite species changed with the introduction of functional radicals (hydroxyl and methoxy groups) onto the acetophenone skeleton. PMID:23855621

Kim, Min-Gi; Yang, Ji-Yeon; Lee, Hoi-Seon

2013-08-01

41

Comparative efficacy of spinosad with conventional acaricides against hard and soft tick populations from Antalya, Turkey.  

PubMed

The acaricidal efficacy of ceramic tiles treated at field application rates with either spinosad (Mozkill 120 SC, 0.01 g ai/m(2)), deltamethrin (Impotek Deltamethrin EW, 0.01 g ai/m(2)), permethrin+esbiothrin (Chrysamed, 0.1 g ai/m(2)), chlorpyrifos-methyl (Chlortoks EC 50, 0.2 g ai/m(2)) or a mixture of alpha-cypermethrin/tetramethrin/piperonyl butoxide (Ecorex Alfa SE, 0.01 g ai/m(2)), against larval Rhipicephalus turanicus and Argas persicus ticks was determined in laboratory bioassays. All ticks were initially exposed to treated tiles for 15 min then removed to non-treated containers and mortality evaluated for 15 min, 1 h, 6 h, and 24 h postexposure. Generally, A. persicus proved to be the most susceptible of the two species to all treatments. The alpha-cypermethrin/tetramethrin/piperonyl butoxide mixture was the quickest acting acaricide against larval A. persicus where 100% mortality was observed 15 min postexposure. For the rest of the treatments complete mortality was obtained at 1 h except for permethrin/esbiothrin which occurred at 6 h postexposure. Complete mortality of larval R. turanicus occurred to deltamethrin and spinosad at 1 h postexposure with all acaricides providing 100% control at 6 h except permethrin/esbiothrin which only achieved 92% control through the end of the study (i.e. 24 h). Our results showed that spinosad would be a useful addition in a tick control program as an alternative for pyrethroids and organic phosphorus acaricides against both tick species. PMID:19446398

Cetin, Huseyin; Cilek, James E; Oz, Emre; Aydin, Levent; Deveci, Onder; Yanikoglu, Atila

2009-07-01

42

Unusual Laboratory Findings in a Case of Norwegian Scabies Provided a Clue to Diagnosis  

PubMed Central

The diagnosis of Norwegian scabies was missed for a year for an elderly long-term-care facility resident. Serpiginous tracks were noted on the surface of Sabouraud dextrose agar used for fungal culture of the skin scrapings. This unusual laboratory manifestation must alert clinical microbiologists to the possible diagnosis of scabies. PMID:15872307

Wong, Samson S. Y.; Woo, Patrick C. Y.; Yuen, Kwok-yung

2005-01-01

43

Crusted scabies is associated with increased IL-17 secretion by skin T cells.  

PubMed

Scabies is an ectoparasitic infestation by the mite Sarcoptes scabiei. Although commonly self-limiting, a fraction of patients develop severely debilitating crusted scabies. The immune mechanisms underlying the development of crusted scabies are unclear, and undertaking longitudinal infection studies in humans is difficult. We utilized a porcine model to compare cellular immune responses in peripheral blood and skin of pigs with different clinical manifestations of scabies (n = 12), and in uninfected controls (n = 6). Although clinical symptoms were not evident until at least 4 weeks post-infestation, the numbers of peripheral IFN?-secreting CD4(+) T cells and ?? T cells increased in infected pigs from week 1 post-infestation. ?? T cells remained increased in the blood at week 15 post-infestation. At week 15, skin cell infiltrates from pigs with crusted scabies had significantly higher CD8(+) T cell, ?? T cell and IL-17(+) cell numbers than those with ordinary scabies. Peripheral IL-17 levels were not increased, suggesting that localized skin IL-17-secreting T cells may play a critical role in the pathogenesis of crusted scabies development. Given the potential of anti-IL-17 immunotherapy demonstrated for other inflammatory skin diseases, this study may provide a novel therapeutic avenue for patients with recurrent crusted scabies. PMID:25040151

Liu, X; Walton, S F; Murray, H C; King, M; Kelly, A; Holt, D C; Currie, B J; McCarthy, J S; Mounsey, K E

2014-11-01

44

Complement Inhibitors from Scabies Mites Promote Streptococcal Growth – A Novel Mechanism in Infected Epidermis?  

Microsoft Academic Search

BackgroundScabies is highly prevalent in socially disadvantaged communities such as indigenous populations and in developing countries. Generalized itching causes discomfort to the patient; however, serious complications can occur as a result of secondary bacterial pyoderma, commonly caused by Streptococcus pyogenes (GAS) or Staphylococcus aureus. In the tropics, skin damage due to scabies mite infestations has been postulated to be an

Angela Mika; Simone L. Reynolds; Darren Pickering; David McMillan; Kadaba S. Sriprakash; David J. Kemp; Katja Fischer

2012-01-01

45

A Tractable Experimental Model for Study of Human and Animal Scabies  

Microsoft Academic Search

BackgroundScabies is a parasitic skin infestation caused by the burrowing mite Sarcoptes scabiei. It is common worldwide and spreads rapidly under crowded conditions, such as those found in socially disadvantaged communities of Indigenous populations and in developing countries. Pruritic scabies lesions facilitate opportunistic bacterial infections, particularly Group A streptococci. Streptococcal infections cause significant sequelae and the increased community streptococcal burden

Kate Mounsey; Mei-Fong Ho; Andrew Kelly; Charlene Willis; Cielo Pasay; David J. Kemp; James S. McCarthy; Katja Fischer

2010-01-01

46

Investigation of a scabies outbreak in a kindergarten in Constance, Germany.  

PubMed

In industrialized countries, scabies occurs sporadically or in the form of protracted epidemics, typically in nursing homes for elderly people. Outbreaks of scabies in a kindergarten are very rare. The main goal of our study was to investigate an outbreak of scabies in a kindergarten and to identify risk factors for the infestation with the ectoparasitosis. We investigated an outbreak of scabies in a kindergarten in the City of Constance, southern Germany, with a particular pedagogical concept. Risk factors indicating a transmission of Sarcoptes mites through body contact or via fomites were assessed using questionnaires and by following the daily routine in the kindergarten. A total of 16 cases were identified. The attack rate was significantly higher in nursery teachers (risk ratio 42.1) compared to children (risk ratio 10.5). In all cases, scabies had developed rather recently, with minimal clinical manifestations. In nursery teachers, the probability of scabies was 4.4 times higher in those teachers who hugged children regularly. Children who preferably played with their own soft toys had a lower probability of developing scabies [risk ratio 0.14, 95 % confidence interval (CI) 0.05-0.42; p?=?0.04]. It seems conceivable that the particular pedagogical concept of the kindergarten favored the spread of Sarcoptes mites. We were unable to show whether transmission had preferably occurred through body contact or via fomites. PMID:23052985

Ariza, L; Walter, B; Worth, C; Brockmann, S; Weber, M-L; Feldmeier, H

2013-03-01

47

The immunology of susceptibility and resistance to scabies.  

PubMed

The transmission of scabies occurs with the burrowing of Sarcoptes scabiei var. hominis mites into the skin. Infestation invariably leads to the development of localized cutaneous inflammation, pruritus and skin lesions. Classical transmission studies document an initial increase in S. scabiei numbers subsequent to primary infestation with a gradual reduction as host immunity develops. However, certain individuals fail to control infection and develop severe crusting of the skin, accompanied with extremely high mite burdens, elevated antibody levels and eosinophilia. These individuals have the nonhealing form of the human disease known as crusted scabies. The genetic predisposition for susceptibility or resistance to S. scabiei infection in humans is hypothesized to correlate with the dominance of an IgE-driven Th2 response in severe disease or an interferon-gamma-dominated Th1 response that promotes parasite control. However, recent data reveals complexities in cytokine regulation in the skin and the mechanisms of acquired resistance and immune escape. In this review, we consider the recent immunological and biomolecular advances in understanding the human host immune response to S. scabiei infestations in the context of earlier studies and attempt to reconcile apparent differences and emphasize those aspects of the Th1/Th2 model that are supported or refined. PMID:20626808

Walton, S F

2010-08-01

48

Scabies in a 2-month-old Infant Successfully Treated with Lindane  

PubMed Central

Diagnosis of scabies in young children can be challenging since the morphology and distribution of skin lesions may differ from adults. Therefore, clinicians should keep scabies in mind in their differential diagnosis in a child who presents with severe pruritic, polymorphic skin lesions. Regarding the treatment of scabies, the reported clinical experience with gamma benzene hexachloride (lindane) in young children is quite limited because of its neurotoxicity. However, a recent review suggests that lindane is an excellent alternative drug with minimal risk. We report the case of a 2-month-old male infant with pruritic, erythematous macules, papules, nodules, vesicles, and pustules from the top of the head to the tip of the toes. Initially, he was thought to have impetigo and antibiotics were prescribed. After obtaining a careful history and with the use of skin scraping, he was diagnosed with scabies. He was successfully treated with lindane with no adverse reactions. PMID:20523787

Jin, Seon Pil; Choi, Ji Eun; Won, Chong-Hyun

2009-01-01

49

Problems in Diagnosing Scabies, a Global Disease in Human and Animal Populations  

PubMed Central

Scabies is a worldwide disease and a major public health problem in many developing countries, related primarily to poverty and overcrowding. In remote Aboriginal communities in northern Australia, prevalences of up to 50% among children have been described, despite the availability of effective chemotherapy. Sarcoptic mange is also an important veterinary disease engendering significant morbidity and mortality in wild, domestic, and farmed animals. Scabies is caused by the ectoparasitic mite Sarcoptes scabiei burrowing into the host epidermis. Clinical symptoms include intensely itchy lesions that often are a precursor to secondary bacterial pyoderma, septicemia, and, in humans, poststreptococcal glomerulonephritis. Although diagnosed scabies cases can be successfully treated, the rash of the primary infestation takes 4 to 6 weeks to develop, and thus, transmission to others often occurs prior to therapy. In humans, the symptoms of scabies infestations can mimic other dermatological skin diseases, and traditional tests to diagnose scabies are less than 50% accurate. To aid early identification of disease and thus treatment, a simple, cheap, sensitive, and specific test for routine diagnosis of active scabies is essential. Recent developments leading to the expression and purification of S. scabiei recombinant antigens have identified a number of molecules with diagnostic potential, and current studies include the investigation and assessment of the accuracy of these recombinant proteins in identifying antibodies in individuals with active scabies and in differentiating those with past exposure. Early identification of disease will enable selective treatment of those affected, reduce transmission and the requirement for mass treatment, limit the potential for escalating mite resistance, and provide another means of controlling scabies in populations in areas of endemicity. PMID:17428886

Walton, Shelley F.; Currie, Bart J.

2007-01-01

50

Diagnosis and treatment of scabies in 2002: rapid diagnosis and proper management limit the risk of spread.  

PubMed

(1) Scabies is due to a parasite, Sarcoptes scabiei hominis, that colonises the human epidermis. It can affect people of all ages, regardless of their socioeconomic status. (2) Common scabies in adults causes sometimes intense pruritus and skin lesions with a characteristic aspect and distribution. The lesions are often more extensive in children. (3) Crusted (hyperkeratotic) scabies, a severe and highly contagious form, mainly occurs in immunocompromised patients. (4) Scabies lesions are often atypical in elderly patients. (5) The diagnosis of common scabies is generally based on clinical findings. Atypical forms can be diagnosed by direct examination of skin scrapings for parasites. (6) Topical treatment is based on insecticides. 5% permethrin is recommended in reference textbooks. Benzyl benzoate (possibly combined with sulfiram) is poorly evaluated. (7) Scabies can be treated more easily with ivermectin, an oral antiparasitic agent. PMID:12378748

2002-10-01

51

Comparison of ivermectin and benzyl benzoate for treatment of scabies.  

PubMed

A randomized investigator-blinded trial of oral ivermectin 100 micrograms/kg single dose vs. benzyl benzoate 10% application in the treatment of scabies, was conducted in 1992 in French Polynesia. In total, 44 patients aged 5-56 years were included in the study: 23 in the group ivermectin (IVER) and 21 in the group benzyl benzoate (BB). At day 30 after treatment, the cumulative recovery rates were 70% (16/23) in the group IVER, and 48% (10/21) in the group BB, 95% confidence intervals 51-87% and 29-70% respectively. The rates of recovery were greater in the group IVER at day 7, 14 and 30, but the difference was not statistically significant. Our results show that oral ivermectin is a valuable alternative to benzyl benzoate local treatment. PMID:8134777

Glaziou, P; Cartel, J L; Alzieu, P; Briot, C; Moulia-Pelat, J P; Martin, P M

1993-12-01

52

An Aspartic Protease of the Scabies Mite Sarcoptes scabiei Is Involved in the Digestion of Host Skin and Blood Macromolecules  

PubMed Central

Background Scabies is a disease of worldwide significance, causing considerable morbidity in both humans and other animals. The scabies mite Sarcoptes scabiei burrows into the skin of its host, obtaining nutrition from host skin and blood. Aspartic proteases mediate a range of diverse and essential physiological functions such as tissue invasion and migration, digestion, moulting and reproduction in a number of parasitic organisms. We investigated whether aspartic proteases may play role in scabies mite digestive processes. Methodology/Principle Findings We demonstrated the presence of aspartic protease activity in whole scabies mite extract. We then identified a scabies mite aspartic protease gene sequence and produced recombinant active enzyme. The recombinant scabies mite aspartic protease was capable of digesting human haemoglobin, serum albumin, fibrinogen and fibronectin, but not collagen III or laminin. This is consistent with the location of the scabies mites in the upper epidermis of human skin. Conclusions/Significance The development of novel therapeutics for scabies is of increasing importance given the evidence of emerging resistance to current treatments. We have shown that a scabies mite aspartic protease plays a role in the digestion of host skin and serum molecules, raising the possibility that interference with the function of the enzyme may impact on mite survival. PMID:24244770

Mahmood, Wajahat; Viberg, Linda T.; Fischer, Katja; Walton, Shelley F.; Holt, Deborah C.

2013-01-01

53

Toxicity of three acaricides to Tetranychus urticae (Tetranychidae: Acari) and Orius insidiosus (Anthocoridae: Hemiptera).  

PubMed

Management for twospotted spider mite, Tetranychus urticae Koch, populations in peanut, Arachis hypogaea L., relies on acaricides. The outcomes of acaricide applications are most predictable when complete information on their toxicity and specificity is available. Specifically, the degrees to which acaricides impact different stages of T. urticae and natural enemies combined determine the overall efficacy of an acaricide application. The objectives of this study were to determine stage-specific direct and residual efficacies of three acaricides (fenpropathrin, etoxazole, and propargite) against T. urticae, and the direct and residual toxicity of the acaricides to Orius insidiosus (Say) adults. Direct toxicity of acaricides to T. urticae was measured on peanut cuttings. All acaricide treatments caused significant mortality to a mixed stage population of T. urticae, and mortality did not differ among the acaricides 7 d after treatment. When toxicity to eggs was tested, the proportion of eggs that hatched for all acaricide treatments was significantly lower than the control, with etoxazole and propargite causing 100% mortality. Exposure to acaricide residues caused < 30% mortality of T. urticae adults 1 and 2 d after treatment and was not significantly different from the control. Fenpropathrin and propargite caused 100% mortality and etoxazole caused > 50% mortality of O. insidious adults after direct exposure to the acaricides. Residual toxicity of acaricides to O. insidiosus adults varied but remained toxic to O. insidiosus longer than to T. urticae. Fenpropathrin had the longest residual effect on O. insidiosus adults, causing > 95% mortality after 14 d; etoxazole and propargite caused < 30% mortality after 14 d. PMID:16573323

Ashley, Janet L; Herbert, D Ames; Lewis, Edwin E; Brewster, Carlyle C; Huckaba, Randy

2006-02-01

54

Effect of owner-controlled acaricidal treatment on tick infestation and immune response to tick-borne pathogens in naturally infested dogs from Eastern Austria  

PubMed Central

Background Tick-borne infections resulting from regular tick infestation in dogs are a common veterinary health problem all over the world. The application of repellent and acaricidal agents to prevent transmission of pathogens is a major protection strategy and has been proven to be highly effective in several trials under laboratory and natural conditions in dogs. Despite such promising results, many dog owners still report tick infestation in their dogs although acaricidal agents are used. Information about the current infection status and changes of the infection status regarding tick-borne diseases (TBD) in dogs treated by the owner’s controlled acaricide application is lacking. Methods In this study 30 dogs were each treated with permethrin, fipronil + S-methoprene, or served as untreated controls. Application of the acaricide was performed by the owner who decided when and how often to use the spot on preparation. Over a period of 11 months, dogs were clinically examined and sampled for antibody responses against Babesia canis, Anaplasma phagocytophilum, Borrelia burgdorferi s. l., and TBE virus before the study started, 6 months later and at the end of the investigation period. Results The permethrin acaricide was applied on average 3.40 times within the examination period, whereas the fipronil + S-methoprene medication was applied 3.03 times. Approximately 2/3 of all dogs, independent of the group, had a positive immune response to one or more pathogens. Three dogs developed clinical symptoms of canine babesiosis, all other dogs remained healthy. Individual number of ticks per dog or number of infections per dog did not correlate with the application rate, and the number of ticks per dog did not influence the number of infections per dog. As owners did not apply the acaricides regularly no influence on the number of infections could be documented although the number of ticks was clearly reduced by the application of the spot-on drugs. Conclusions Clinical disease in dogs exposed to tick-borne pathogens is rare, although a humoral immune response reflecting infection is common. More educational training for dog owners is necessary to make the application of acaricides effective regarding the prevention of tick-borne diseases. PMID:23497548

2013-01-01

55

Clinical and parasitological study on scabies in Sirte, Libya.  

PubMed

The present work aimed to determine the risk factors, clinical and parasitological skin lesion features and effective drug regimens. Study was carried out on 200 patients referred to dermatology outpatient clinics in Sirte-Libya. Each was subjected to detailed questionnaire, dermatological skin examination, parasitological skin scraping test (SST), burrow ink test (BIT), drug administration and follow up. Results revealed that females 59%, children 37.5% and military personnel 18% of immigrant families were particularly prone to scabies infestation. Effective risk factors included overcrowding, bed sharing, low hygienic and education levels. Commonest skin lesions included erythematous papules 93%, excoriated papules 77.5%, burrows 66%, pustulation 31%, vesicles 21.5 and nodules 3%. Predilection lesion sites were hand 86%, wrist 82%, abdomen 56%, male external genitalia 64.5% and female breast 28%. Specific SST was positive in 67.3% of cases, particularly sensitive in early cases with short itching duration. BIT was positive in 62%. Topical permethrin proved more effective than precipitated sulpher with cure rates of of 100% and 85.3% in 21% and 75% of cases, respectively. Ivermectin was 100% effective in 4% of cases. PMID:21268539

Fathy, Fouad M; El-Kasah, Fathi; El-Ahwal, Abdulla M

2010-12-01

56

Control of scabies, skin sores and haematuria in children in the Solomon Islands: another role for ivermectin.  

PubMed Central

OBJECTIVE: To assess the effects of a 3-year programme aimed at controlling scabies on five small lagoon islands in the Solomon Islands by monitoring scabies, skin sores, streptococcal skin contamination, serology and haematuria in the island children. METHODS: Control was achieved by treating almost all residents of each island once or twice within 2 weeks with ivermectin (160-250 microg/kg), except for children who weighed less than 15 kg and pregnant women, for whom 5% permethrin cream was used. Reintroduction of scabies was controlled by treating returning residents and visitors, whether or not they had evident scabies. FINDINGS: Prevalence of scabies dropped from 25% to less than 1% (P < 0.001); prevalence of sores from 40% to 21% (P < 0.001); streptococcal contamination of the fingers in those with and without sores decreased significantly (P = 0.02 and 0.047, respectively) and anti-DNase B levels decreased (P = 0.002). Both the proportion of children with haematuria and its mean level fell (P = 0.002 and P < 0.001, respectively). No adverse effects of the treatments were seen. CONCLUSION: The results show that ivermectin is an effective and practical agent in the control of scabies and that control reduces the occurrence of streptococcal skin disease and possible signs of renal damage in children. Integrating community-based control of scabies and streptococcal skin disease with planned programmes for controlling filariasis and intestinal nematodes could be both practical and produce great health benefits. PMID:15682247

Lawrence, Gregor; Leafasia, Judson; Sheridan, John; Hills, Susan; Wate, Janet; Wate, Christine; Montgomery, Janet; Pandeya, Nirmala; Purdie, David

2005-01-01

57

A comparative study of oral ivermectin and topical permethrin cream in the treatment of scabies  

Microsoft Academic Search

Background: The conventional antiscabietics have poor compliance. Ivermectin, an oral antiparasitic drug, has been shown to be an effective scabicide and could be a useful substitute. Objective: This study compares the efficacy of oral ivermectin with topical permethrin cream in the treatment of scabies. Methods: Eighty-five consecutive patients were randomized into 2 groups. Forty patients and their family contacts received

V. Usha; T. V. Gopalakrishnan Nair

2000-01-01

58

Scabies Mite Peritrophins Are Potential Targets of Human Host Innate Immunity  

Microsoft Academic Search

BackgroundPruritic scabies lesions caused by Sarcoptes scabiei burrowing in the stratum corneum of human skin facilitate opportunistic bacterial infections. Emerging resistance to current therapeutics emphasizes the need to identify novel targets for protective intervention. We have characterized several protein families located in the mite gut as crucial factors for host-parasite interactions. Among these multiple proteins inhibit human complement, presumably to

Angela Mika; Priscilla Goh; Deborah C. Holt; Dave J. Kemp; Katja Fischer

2011-01-01

59

Comparison of oral ivermectin versus crotamiton 10% cream in the treatment of scabies.  

PubMed

Abstract Objective: Scabies is a relatively contagious infection caused by a tiny mite (Sarcoptes scabiei). Products used to treat scabies are called scabicides because they kill scabies mites; some also kill mite eggs. The aim of this study was to compare the efficacy and safety of oral ivermectin versus crotamiton 10% cream for the treatment of scabies. Methods: In total, 320 patients with scabies were enrolled, and were randomized into two groups: the first group received a single dose of oral ivermectin 200?µg/kg body weight, and the second group were treated with crotamiton 10% cream and were told to apply this twice daily for five consecutive days. Treatment was evaluated at intervals of two and four weeks, and if there was treatment failure at the two-week follow-up, the treatment was repeated. Results: A single dose of ivermectin provided a cure rate of 62.5% at the two-week follow-up, which increased to 87.5% at the four-week follow-up after repeating the treatment. Treatment with crotamiton 10% cream was effective in 46.8% of patients at the two-week follow-up, which increased to 62.5% at the four-week follow-up after this treatment was repeated. Conclusion: A single dose of ivermectin was as effective as one application of crotamiton 10% cream at the two-week follow-up. After repeat treatment, ivermectin was superior to crotamiton 10% cream at the four-week follow up. The delay in clinical response with ivermectin suggests that it may not be effective against all the stages in the life cycle of the parasite. PMID:23431958

Goldust, Mohamad; Rezaee, Elham; Raghifar, Ramin

2013-02-25

60

Scabies mite inactivated serine protease paralogues are present both internally in the mite gut and externally in feces.  

PubMed

The scabies mite, Sarcoptes scabiei, is the causative agent of scabies, a disease that is common among disadvantaged populations and facilitates streptococcal infections with serious sequelae. Previously, we encountered large families of genes encoding paralogues of house dust mite protease allergens with their catalytic sites inactivated by mutation (scabies mite inactivated protease paralogues [SMIPPs]). We postulated that SMIPPs have evolved as an adaptation to the parasitic lifestyle of the scabies mite, functioning as competitive inhibitors of proteases involved in the host-parasite interaction. To propose testable hypotheses for their functions, it is essential to know their locations in the mite. Here we show by immunohistochemistry that SMIPPs exist in two compartments: 1) internal to the mite in the gut and 2) external to the mite after excretion from the gut in scybala (fecal pellets). SMIPPs may well function in both of these compartments to evade host proteases. PMID:17038694

Willis, Charlene; Fischer, Katja; Walton, Shelley F; Currie, Bart J; Kemp, David J

2006-10-01

61

Scabies Mite Peritrophins Are Potential Targets of Human Host Innate Immunity  

PubMed Central

Background Pruritic scabies lesions caused by Sarcoptes scabiei burrowing in the stratum corneum of human skin facilitate opportunistic bacterial infections. Emerging resistance to current therapeutics emphasizes the need to identify novel targets for protective intervention. We have characterized several protein families located in the mite gut as crucial factors for host-parasite interactions. Among these multiple proteins inhibit human complement, presumably to avoid complement-mediated damage of gut epithelial cells. Peritrophins are major components of the peritrophic matrix often found in the gut of arthropods. We hypothesized that a peritrophin, if abundant in the scabies mite gut, could be an activator of complement. Methodology/Principal Findings A novel full length scabies mite peritrophin (SsPTP1) was identified in a cDNA library from scabies mites. The amino acid sequence revealed four putative chitin binding domains (CBD). Recombinant expression of one CBD of the highly repetitive SsPTP1 sequence as TSP-hexaHis-fusion protein resulted in soluble protein, which demonstrated chitin binding activity in affinity chromatography assays. Antibodies against a recombinant SsPTP1 fragment were used to immunohistochemically localize native SsPTP1 in the mite gut and in fecal pellets within the upper epidermis, co-localizing with serum components such as host IgG and complement. Enzymatic deglycosylation confirmed strong N- and O-glycosylation of the native peritrophin. Serum incubation followed by immunoblotting with a monoclonal antibody against mannan binding lectin (MBL), the recognition molecule of the lectin pathway of human complement activation, indicated that MBL may specifically bind to glycosylated SsPTP1. Conclusions/Significance This study adds a new aspect to the accumulating evidence that complement plays a major role in scabies mite biology. It identifies a novel peritrophin localized in the mite gut as a potential target of the lectin pathway of the complement cascade. These initial findings indicate a novel role of scabies mite peritrophins in triggering a host innate immune response within the mite gut. PMID:21980545

Holt, Deborah C.; Kemp, Dave J.; Fischer, Katja

2011-01-01

62

Scabies in animals and humans: history, evolutionary perspectives, and modern clinical management.  

PubMed

Scabies, a mite infestation frequently sexually transmitted, dates back to antiquity but remains a challenging parasite for study in clinical practice and community settings. Its history is one of centuries of slow progress to recognize the mite and to finally establish its nexus to the clinical syndrome of pruritis with several protean manifestations and different epidemiological patterns. Contemporary methods of management are briefly reviewed, with the future promise of improved evolutionary knowledge associated with the advent of molecular and genetic technology. Current information indicates that humans and earlier protohumans were most likely the source of animal scabies, first of dogs, and later of other species with subsequent spread to wildlife. Morphologically identical variants of Sarcoptes scabiei are nonetheless host specific, as determined by recent DNA studies, and invite future investigations into the dynamics of this troublesome sexually transmissible agent, with the goal of improved recognition and control. PMID:22417107

Currier, Russell W; Walton, Shelley F; Currie, Bart J

2011-08-01

63

[Scabies and the significance of "suriones" in the handwritten manuscripts of Hildegard von Bingen].  

PubMed

In her studies on nature and medicine, the "Liber simplicis medicinae" (LSM or "Physica") and the "Liber compositae medicinae" (LCM or "Causae et Curae"), Hildegard von Bingen mentions Scabies (mange) in several passages. She characterizes "suren aut (= or) sneuelzen" as the cause of the disease, which she calls also "gracillimi vermiculi", that is, tiny worms that burrow into the human skin ("ubi suren aut sneuelzen hominem comedendo ledunt"). In this context the meanings of the German-ancestor terms "suren aut sneuelzen", which are found in the Latin text concerning the "Alia Mynza", are still disputed. The question whether Hildegard knew the cause of scabies the author discusses on the basis of ancient and medieval sources as well as modem medical historical and philological/linguistic research approaches. He concludes that Hildegard was able not only to describe the symptoms exactly, but also to define the cause of the disease as a special parasite. Consequently, she differentiates other diseases of the skin, such as "grint", from scabies. The proposed interpretation of "sneuelzen" as the tick is untenable. The assumption that both terms are synonyms for sarcoptes scabiei can be confirmed by philological and medical historical research. PMID:17338404

Riethe, Peter

2006-01-01

64

Repellent and acaricidal effects of botanical extracts on Varroa destructor.  

PubMed

Extracts of indigenous plants from South America have shown a broad spectrum of bioactivities. No-contaminant and natural substances have recently resurged as control treatment options for varroosis in honey bee colonies from Argentina. The aim of this work was to evaluate the biological activity of botanical extracts from Baccharis flabellata and Minthostachys verticillata on Varroa destructor and Apis mellifera. The acaricidal and insecticidal activities were assessed by the spraying application method. Both ethanolic extracts showed high levels of toxicity against the mites and were harmless to their host, A. mellifera. During the attractive-repellent test, the olfactory stimulus evoked for the extract from B. flabellata resulted as a repellent for mites. The aromatic stimulus of these extracts would be strong enough to cause disturbance on the behavior of V. destructor. Thus, the repellent effect of these substances plus the toxicity on mites postulate these botanical extracts like promising natural compound to be incorporated for the control of varroosis. PMID:20838808

Damiani, Natalia; Gende, Liesel B; Maggi, Matías D; Palacios, Sara; Marcangeli, Jorge A; Eguaras, Martín J

2011-01-01

65

Topically applied myco-acaricides for the control of cattle ticks: overcoming the challenges  

Microsoft Academic Search

In the absence of commercially viable and environmentally friendly options, the management of cattle ticks is heavily dependent\\u000a on the use of chemical acaricides. Due to recent advances in production, formulation and application technology, commercial\\u000a fungus-based biological pesticides (myco-insecticides, myco-acaricides) are becoming increasingly popular for the control\\u000a of plant pests; however, they have not been used against animal ectoparasites. The

Perry Polar; Dave Moore; Moses T. K. Kairo; Adash Ramsubhag

66

Topically applied myco-acaricides for the control of cattle ticks: overcoming the challenges  

Microsoft Academic Search

In the absence of commercially viable and environmentally friendly options, the management of cattle ticks is heavily dependent\\u000a on the use of chemical acaricides. Due to recent advances in production, formulation and application technology, commercial\\u000a fungus-based biological pesticides (myco-insecticides, myco-acaricides) are becoming increasingly popular for the control\\u000a of plant pests; however, they have not been used against animal ectoparasites. The

Perry Polar; Dave Moore; Moses T. K. Kairo; Adash Ramsubhag

2008-01-01

67

Acaricidal properties of Ricinus communis leaf extracts against organophosphate and pyrethroids resistant Rhipicephalus (Boophilus) microplus.  

PubMed

Indian cattle ticks have developed resistance to commonly used acaricides and an attempt has been made to formulate an ecofriendly herbal preparation for the control of acaricide resistant ticks. A 95% ethanolic extract of Ricinus communis was used to test the efficacy against reference acaricide resistant lines by in vitro assay. In in vitro assay, the extract significantly affects the mortality rate of ticks in dose-dependent manner ranging from 35.0 ± 5.0 to 95.0 ± 5.0% with an additional effect on reproductive physiology of ticks by inhibiting 36.4-63.1% of oviposition. The leaf extract was found effective in killing 48.0, 56.7 and 60.0% diazinon, deltamethrin and multi-acaricide resistant ticks, respectively. However, the cidal and oviposition limiting properties of the extract were separated when the extract was fractionated with hexane, chloroform, n-butanol and water. The HPTLC finger printing profile of R. communis leaf extract under ?(max.) - 254 showed presence of quercetin, gallic acid, flavone and kaempferol which seemed to have synergistic acaricidal action. In vivo experiment resulted in 59.9% efficacy on Ist challenge, however, following 2nd challenge the efficacy was reduced to 48.5%. The results indicated that the 95% ethanolic leaf extract of R. communis can be used effectively in integrated format for the control of acaricide resistant ticks. PMID:23084038

Ghosh, Srikanta; Tiwari, Shashi Shankar; Srivastava, Sharad; Sharma, Anil Kumar; Kumar, Sachin; Ray, D D; Rawat, A K S

2013-02-18

68

Susceptibilities of northern fowl mite, Ornithonyssus sylviarum (Acarina: Macronyssidae), and chicken mite, Dermanyssus gallinae (Acarina: Dermanyssidae), to selected acaricides  

Microsoft Academic Search

The relative toxicities of ten acaricides to northern fowl mite,Ornithonyssus sylviarum (Canestrini and Fanzago), and the chicken mite,Dermanyssus gallinae (De Geer), were determined simultaneously by holding the mites inside disposable glass Pasteur pipettes previously immersed in acetone solutions of various concentrations (w\\/v) of technical grade acaricides. The LC90s (parts per million) of the acaricides after 24 h exposure for the

M. G. Fletcher; R. C. Axtell

1991-01-01

69

Scabies Mite Inactive Serine Proteases Are Potent Inhibitors of the Human Complement Lectin Pathway  

PubMed Central

Scabies is an infectious skin disease caused by the mite Sarcoptes scabiei and has been classified as one of the six most prevalent epidermal parasitic skin diseases infecting populations living in poverty by the World Health Organisation. The role of the complement system, a pivotal component of human innate immunity, as an important defence against invading pathogens has been well documented and many parasites have an arsenal of anti-complement defences. We previously reported on a family of scabies mite proteolytically inactive serine protease paralogues (SMIPP-Ss) thought to be implicated in host defence evasion. We have since shown that two family members, SMIPP-S D1 and I1 have the ability to bind the human complement components C1q, mannose binding lectin (MBL) and properdin and are capable of inhibiting all three human complement pathways. This investigation focused on inhibition of the lectin pathway of complement activation as it is likely to be the primary pathway affecting scabies mites. Activation of the lectin pathway relies on the activation of MBL, and as SMIPP-S D1 and I1 have previously been shown to bind MBL, the nature of this interaction was examined using binding and mutagenesis studies. SMIPP-S D1 bound MBL in complex with MBL-associated serine proteases (MASPs) and released the MASP-2 enzyme from the complex. SMIPP-S I1 was also able to bind MBL in complex with MASPs, but MASP-1 and MASP-2 remained in the complex. Despite these differences in mechanism, both molecules inhibited activation of complement components downstream of MBL. Mutagenesis studies revealed that both SMIPP-Ss used an alternative site of the molecule from the residual active site region to inhibit the lectin pathway. We propose that SMIPP-Ss are potent lectin pathway inhibitors and that this mechanism represents an important tool in the immune evasion repertoire of the parasitic mite and a potential target for therapeutics. PMID:24854034

Reynolds, Simone L.; Pike, Robert N.; Mika, Angela; Blom, Anna M.; Hofmann, Andreas; Wijeyewickrema, Lakshmi C.; Fischer, Katja

2014-01-01

70

Scabies mite inactive serine proteases are potent inhibitors of the human complement lectin pathway.  

PubMed

Scabies is an infectious skin disease caused by the mite Sarcoptes scabiei and has been classified as one of the six most prevalent epidermal parasitic skin diseases infecting populations living in poverty by the World Health Organisation. The role of the complement system, a pivotal component of human innate immunity, as an important defence against invading pathogens has been well documented and many parasites have an arsenal of anti-complement defences. We previously reported on a family of scabies mite proteolytically inactive serine protease paralogues (SMIPP-Ss) thought to be implicated in host defence evasion. We have since shown that two family members, SMIPP-S D1 and I1 have the ability to bind the human complement components C1q, mannose binding lectin (MBL) and properdin and are capable of inhibiting all three human complement pathways. This investigation focused on inhibition of the lectin pathway of complement activation as it is likely to be the primary pathway affecting scabies mites. Activation of the lectin pathway relies on the activation of MBL, and as SMIPP-S D1 and I1 have previously been shown to bind MBL, the nature of this interaction was examined using binding and mutagenesis studies. SMIPP-S D1 bound MBL in complex with MBL-associated serine proteases (MASPs) and released the MASP-2 enzyme from the complex. SMIPP-S I1 was also able to bind MBL in complex with MASPs, but MASP-1 and MASP-2 remained in the complex. Despite these differences in mechanism, both molecules inhibited activation of complement components downstream of MBL. Mutagenesis studies revealed that both SMIPP-Ss used an alternative site of the molecule from the residual active site region to inhibit the lectin pathway. We propose that SMIPP-Ss are potent lectin pathway inhibitors and that this mechanism represents an important tool in the immune evasion repertoire of the parasitic mite and a potential target for therapeutics. PMID:24854034

Reynolds, Simone L; Pike, Robert N; Mika, Angela; Blom, Anna M; Hofmann, Andreas; Wijeyewickrema, Lakshmi C; Kemp, Dave; Fischer, Katja

2014-05-01

71

A Scabies Mite Serpin Interferes with Complement-Mediated Neutrophil Functions and Promotes Staphylococcal Growth  

PubMed Central

Background Scabies is a contagious skin disease caused by the parasitic mite Sarcoptes scabiei. The disease is highly prevalent worldwide and known to predispose to secondary bacterial infections, in particular by Streptococcus pyogenes and Staphylococcus aureus. Reports of scabies patients co-infected with methicillin resistant S. aureus (MRSA) pose a major concern for serious down-stream complications. We previously reported that a range of complement inhibitors secreted by the mites promoted the growth of S. pyogenes. Here, we show that a recently characterized mite serine protease inhibitor (SMSB4) inhibits the complement-mediated blood killing of S. aureus. Methodology/Principal Findings Blood killing of S. aureus was measured in whole blood bactericidal assays, counting viable bacteria recovered after treatment in fresh blood containing active complement and phagocytes, treated with recombinant SMSB4. SMSB4 inhibited the blood killing of various strains of S. aureus including methicillin-resistant and methicillin-sensitive isolates. Staphylococcal growth was promoted in a dose-dependent manner. We investigated the effect of SMSB4 on the complement-mediated neutrophil functions, namely phagocytosis, opsonization and anaphylatoxin release, by flow cytometry and in enzyme linked immuno sorbent assays (ELISA). SMSB4 reduced phagocytosis of S. aureus by neutrophils. It inhibited the deposition of C3b, C4b and properdin on the bacteria surface, but did not affect the depositions of C1q and MBL. SMSB4 also inhibited C5 cleavage as indicated by a reduced C5b-9 deposition. Conclusions/Significance We postulate that SMSB4 interferes with the activation of all three complement pathways by reducing the amount of C3 convertase formed. We conclude that SMSB4 interferes with the complement-dependent killing function of neutrophils, thereby reducing opsonization, phagocytosis and further recruitment of neutrophils to the site of infection. As a consequence secreted scabies mites complement inhibitors, such as SMSB4, provide favorable conditions for the onset of S. aureus co-infection in the scabies-infected microenvironment by suppressing the immediate host immune response. PMID:24945501

Swe, Pearl M.; Fischer, Katja

2014-01-01

72

Novel Scabies Mite Serpins Inhibit the Three Pathways of the Human Complement System  

PubMed Central

Scabies is a parasitic infestation of the skin by the mite Sarcoptes scabiei that causes significant morbidity worldwide, in particular within socially disadvantaged populations. In order to identify mechanisms that enable the scabies mite to evade human immune defenses, we have studied molecules associated with proteolytic systems in the mite, including two novel scabies mite serine protease inhibitors (SMSs) of the serpin superfamily. Immunohistochemical studies revealed that within mite-infected human skin SMSB4 (54 kDa) and SMSB3 (47 kDa) were both localized in the mite gut and feces. Recombinant purified SMSB3 and SMSB4 did not inhibit mite serine and cysteine proteases, but did inhibit mammalian serine proteases, such as chymotrypsin, albeit inefficiently. Detailed functional analysis revealed that both serpins interfered with all three pathways of the human complement system at different stages of their activation. SMSB4 inhibited mostly the initial and progressing steps of the cascades, while SMSB3 showed the strongest effects at the C9 level in the terminal pathway. Additive effects of both serpins were shown at the C9 level in the lectin pathway. Both SMSs were able to interfere with complement factors without protease function. A range of binding assays showed direct binding between SMSB4 and seven complement proteins (C1, properdin, MBL, C4, C3, C6 and C8), while significant binding of SMSB3 occurred exclusively to complement factors without protease function (C4, C3, C8). Direct binding was observed between SMSB4 and the complement proteases C1s and C1r. However no complex formation was observed between either mite serpin and the complement serine proteases C1r, C1s, MASP-1, MASP-2 and MASP-3. No catalytic inhibition by either serpin was observed for any of these enzymes. In summary, the SMSs were acting at several levels mediating overall inhibition of the complement system and thus we propose that they may protect scabies mites from complement-mediated gut damage. PMID:22792350

Mika, Angela; Reynolds, Simone L.; Mohlin, Frida C.; Willis, Charlene; Swe, Pearl M.; Pickering, Darren A.; Halilovic, Vanja; Wijeyewickrema, Lakshmi C.; Pike, Robert N.; Blom, Anna M.; Kemp, David J.; Fischer, Katja

2012-01-01

73

Comparative toxicity of acaricides to honey bee (Hymenoptera: Apidae) workers and queens.  

PubMed

Acaricides are used to treat honey bee (Apis mellifera L.) colonies to control the varroa mite (Varroa destructor Anderson & Trueman), a worldwide threat to honey bee health. Although acaricides control a serious honey bee parasite and mitigate bee loss, they may cause harm to bees as well. We topically applied five acaricides, each with a different mode of action, to young adult queen and worker bees to generate dose-response curves and LD50. Twenty-four hours after treatment, queens were found to be three-times more tolerant of tau-fluvalinate and six-times more tolerant of thymol than workers when adjusted for body weight differences between workers (108 mg) and queens (180 mg). Queens survived the highest administered doses of fenpyroximate (1620 microg/g) and coumaphos (2700 microg/g) indicating that queens are at least 11-fold more tolerant of coumaphos and at least 54-fold more tolerant of fenpyroximate than workers. However, queens treated with as little as 54 microg/g of fenpyroximate exhibited reduced survival over 6 wk after treatment. Amitraz was the only acaricide tested for which queens were not more tolerant than workers. The striking difference in acaricide tolerance of queen and worker honey bees suggests physiological differences in how the two castes are affected by xenobiotics. PMID:23356051

Dahlgren, Lizette; Johnson, Reed M; Siegfried, Blair D; Ellis, Marion D

2012-12-01

74

Acaricides efficiency on Rhipicephalus (Boophilus) microplus from Bahia state North-Central region.  

PubMed

The cattle tick Rhipicephalus (Boophilus) microplus is responsible for major losses in the Brazilian livestock, mainly due to reduction in cattle productive performance. Resistance development to major classes of acaricide widely used nowadays has been extensively reported, as well as the occurrence of residues from these compounds in animal products and the environment. This study aimed to evaluate the efficiency of acaricides on R. (B.) microplus collected from rural properties in the North-Central region of Bahia State. Ticks were collected in several cattle farms in the cited region, and an in vitro acaricide efficiency assay was performed based on the immersion of ticks in acaricide solutions made according to manufacturers' recommendations. The results obtained in the experiments indicated varying degrees of efficiency of the several bases studied, with the products benzofenilurea, macrocyclic lactone and fipronil showing the highest levels of efficiency, 100%, 100% and 97.34%, respectively. It was possible to conclude that, for the region studied, there are different degrees of commercial acaricides efficiency, and many present less than 95% effectiveness, value determined as acceptable by the Brazilian legislation. PMID:23538503

Raynal, José Tadeu; Silva, Aretha Alves Borges da; Sousa, Thiago de Jesus; Bahiense, Thiago Campanharo; Meyer, Roberto; Portela, Ricardo Wagner

2013-01-01

75

Acaricide activity in vitro of Acmella oleracea against Rhipicephalus microplus.  

PubMed

Cattle tick control has been limited by the resistance of these parasites to synthetic acaricides. Natural products are a possible alternative as they have different mechanisms of action. Acmella oleracea is a native plant with a large cultivated area in the Amazon region and could be easily used for large-scale preparation of a commercial product. This study evaluated the in vitro action of the hexane extract of the aerial parts of A. oleracea on larvae and engorged females of the cattle tick Rhipicephalus microplus. Spilanthol was the major constituent with a content of 14.8% in the extract. The hexane extract of A. oleracea was highly effective against larvae of R. microplus with an LC50 of 0.8 mg mL(-1). Against engorged females, hexane extract of A. oleracea reduced oviposition and hatchability of eggs with an LC50 of 79.7 mg mL(-1). Larvae and engorged females were killed by the hexane extract with high efficiency (>95%) at concentrations of 3.1 and 150.0 mg mL(-1), respectively. These results demonstrate that the hexane extract of A. oleracea has significant activity against R. microplus and has potential to be developed into formulations for tick control. PMID:25033813

Castro, K N C; Lima, D F; Vasconcelos, L C; Leite, J R S A; Santos, R C; Paz Neto, A A; Costa-Júnior, L M

2014-10-01

76

Selection and Characterization of Microorganisms Utilizing Thaxtomin A, a Phytotoxin Produced by Streptomyces scabies  

PubMed Central

Thaxtomin A is the main phytotoxin produced by Streptomyces scabies, a causal agent of potato scab. Thaxtomin A is a yellow compound composed of 4-nitroindol-3-yl-containing 2,5-dioxopiperazine. A collection of nonpathogenic streptomycetes isolated from potato tubers and microorganisms recovered from a thaxtomin A solution were examined for the ability to grow in the presence of thaxtomin A as a sole carbon or nitrogen source. Three bacterial isolates and two fungal isolates grew in thaxtomin A-containing media. Growth of these organisms resulted in decreases in the optical densities at 400 nm of culture supernatants and in 10% reductions in the thaxtomin A concentration. The fungal isolates were identified as a Penicillium sp. isolate and a Trichoderma sp. isolate. One bacterial isolate was associated with the species Ralstonia pickettii, and the two other bacterial isolates were identified as Streptomyces sp. strains. The sequences of the 16S rRNA genes were determined in order to compare thaxtomin A-utilizing actinomycetes to the pathogenic organism S. scabies and other Streptomyces species. The nucleotide sequences of the ? variable regions of the 16S ribosomal DNA of both thaxtomin A-utilizing actinomycetes were identical to the sequence of Streptomyces mirabilis ATCC 27447. When inoculated onto potato tubers, the three thaxtomin A-utilizing bacteria protected growing plants against common scab, but the fungal isolates did not have any protective effect. PMID:9797282

Doumbou, Cyr Lézin; Akimov, Vladimir; Beaulieu, Carole

1998-01-01

77

Microarray analysis of acaricide-inducible gene expression in the southern cattle tick, Rhipicephalus (Boophilus) microplus.  

PubMed

Acaricide-inducible differential gene expression was studied in larvae of Rhipicephalus (Boophilus) microplus using a microarray-based approach. The acaricides used were: coumaphos, permethrin, ivermectin, and amitraz. The microarrays contained over 13 000 probes, having been derived from a previously described R. microplus gene index (BmiGI Version 2; Wang et al., 2007). Relative quantitative reverse transcriptase-PCR, real time PCR, and serial analysis of gene expression data was used to verify microarray data. Among the differentially expressed genes with informative annotation were legumain, glutathione S-transferase, and a putative salivary gland-associated protein. PMID:18834453

Saldivar, L; Guerrero, F D; Miller, R J; Bendele, K G; Gondro, C; Brayton, K A

2008-12-01

78

Acaricidal activity of tonka bean extracts. Synthesis and structure-activity relationships of bioactive derivatives.  

PubMed

The acaricidal effects of tonka bean, Dipterix odorata, extracts were investigated on Dermatophagoides pteronyssinus, the European house dust mite, and compared with benzyl benzoate as a standard acaricidal compound. A cyclohexane extract was the most effective, with an EC(50) = 0.075 g/m(2) after a 24 h period, as compared with benzyl benzoate (0.025 g/m(2)). Bioassay-guided fractionation of this extract led to the isolation of coumarin (1). Pharmacomodulation of this compound led us to test 20 analogues (2-21), which were either synthesized or purchased. PMID:12762809

Gleye, Christophe; Lewin, Guy; Laurens, Alain; Jullian, Jean-Christophe; Loiseau, Philippe; Bories, Christian; Hocquemiller, Reynald

2003-05-01

79

Efficacy of triclosan soap against superficial dermatomycoses and scabies : a placebo-controlled study among 228 primary school children in Kilombero district, Mororgoro region, Tanzania.  

E-print Network

??Background: The present placebo-controlled double-blind study was performed to assess the clinical efficacy of Triclosan against selected superficial dermatomycoses and scabies. The overall effect of… (more)

Dinkela, Almuth

2005-01-01

80

[Human T-lymphotropic virus 1 (HTLV-1), strongyloidiasis and scabies. Infections and associations to considerate].  

PubMed

Human T-lymphotropic virus 1 (HTLV-1) is classified into the family of Retroviridae and preferentially causes a chronic infection of CD4+ T cells. Most people infected with HTLV-1 remain asymptomatic. However, less than 105 of infected individuals eventually develop any of the associated severe diseases such as inflammatory syndromes, neoplastic diseases and opportunistic infections including Strongyloides stercoralis and Sarcoptes scabiei hyperinfections. Recently, it has been described that a weak Th2 cell-mediated response is associated with HTLV-1 infection and Strongyloides hyperinfection. The evaluation for HTLV-1 in all Norwegian scabies and S. stercoralis hyperinfection cases is highly recommended, especially when no other risk factors are apparent, in order to start a specific therapy against these parasite-virus coinfections. PMID:19245164

Freites, Azael

2008-12-01

81

Synthesis, insecticidal, and acaricidal activities of novel 2-aryl-pyrrole derivatives containing ester groups.  

PubMed

A series of novel 2-aryl-pyrrole derivatives containing ester groups were synthesized, and their structures were characterized by (1)H NMR spectroscopy and elemental analysis. The insecticidal activities against oriental armyworm, mosquito, diamondback moth, green rice leafhopper, and bean aphids and acaricidal activities against spider mite of these new compounds were evaluated. The results of bioassays indicated that some of these title compounds exhibited excellent insecticidal and acaricidal activities. The insecticidal activities against oriental armyworm of compounds IVa, IVd, IVe, IVf, IVg, IVi, IVk, and IVp were equal to commercialized Chlorfenapyr, and the insecticidal activities of most of compounds IVb, IVc, IVd, IVf, IVg, IVj, IVk, IVl, IVs, IVt, IVu, IVw, IVx, IVz, and Chlorfenapyr against mosquito at 0.10 mg kg (-1) were 100%, and the acaricidal activities of compounds IVd, IVe, IVf, IVg, IVh, IVi, and IVk were equal or superior to Chlorfenapyr. Especially, the results indicated that the acaricidal activity of [4-bromo-2-(4-chlorophenyl)-3-cyano-5-(trifluoromethyl)pyrrol-1-yl]methyl 3-methylbutanoate ( IVg) against spider mite was 2.65-fold as high as that of Chlorfenapyr from the value of LC 50. PMID:18937487

Zhao, Yu; Li, Yongqiang; Ou, Xiaoming; Zhang, Pengxiang; Huang, Zhiqiang; Bi, Fuchun; Huang, Runqiu; Wang, Qingmin

2008-11-12

82

Plant essential oils and formamidines as insecticides/ acaricides: what are the molecular targets?  

E-print Network

Plant essential oils and formamidines as insecticides/ acaricides: what are the molecular targets to combat Varroa mites. Nowadays, mainly plant essential oils and organic acids are applied because they are safer and impose less unfavorable effects on the environment. Essential oils contain mixtures of mostly

83

Effect of a botanical acaricide on Ixodes scapularis (Acari: Ixodidae) and nontarget arthropods.  

PubMed

We tested the effectiveness of the rosemary oil-based insecticide, Eco-Exempt IC2, to control all stages of Ixodes scapularis (Say) in southern Maine. We selected plots in oak-pine forest where I. scapularis is endemic and recorded the abundance of ticks and nontarget arthropods before and after applications of IC2, bifenthrin (a synthetic pyrethroid), and water (reference treatment). Licensed applicators applied high-pressure spray treatments during the summer nymphal and fall adult seasonal peaks. Both acaricides sprayed during the summer nymphal season reduced nymphal I. scapularis/hour to zero. IC2 was as effective as bifenthrin in controlling nymphs through the rest of the nymphal season and also controlled adult ticks 9 mo postspray compared with 16 mo for bifenthrin, and both acaricides reduced larvae through 14 mo postspray. Both acaricides sprayed during the fall adult season reduced adult I. scapularis/hour to zero; IC2 controlled adult ticks 6 mo postspray compared with 1 yr for bifenthrin. Both fall-applied acaricides controlled nymphs 9 mo postspray and reduced larvae up to 10 mo postspray. Impacts on some nontarget arthropods was assessed. Colleoptera, Hymenoptera, and Collembola declined 1 wk postspray in acaricide-treated plots, and in IC2 plots all numbers rebounded by 20 d postspray. For bees and other flower-visiting insects there were no detectable reductions in nests produced, number emerged from nests, or number of foraging visits to flowering plants in IC2 or bifenthrin plots. IC2 was phytotoxic to the leafy portions of select understory plants that appeared to recover by the next growing season. PMID:23427661

Elias, Susan P; Lubelczyk, Charles B; Rand, Peter W; Staples, Joseph K; St Amand, Theodore W; Stubbs, Constance S; Lacombe, Eleanor H; Smith, Leticia B; Smith, Robert P

2013-01-01

84

Acaricidal activities of materials derived from Pyrus ussuriensis fruits against stored food mites.  

PubMed

The acaricidal activities of materials derived from Pyrus ussuriensis fruits were evaluated against Tyrophagus putrescentiae and compared with that of commercial acaricide (benzyl benzoate). On the basis of the 50 % lethal dose (LD(50)) values, the ethyl acetate fraction of the fractions obtained from an aqueous extract of P. ussuriensis fruits had the highest acaricidal activity (16.32 ?g/cm(2)) against T. putrescentiae. The acaricidal constituent of P. ussuriensis fruits was isolated by chromatographic techniques and identified as 1,4-benzoquinone. On the basis of the LD(50) values, 1,4-benzoquinone (1.98 ?g/cm(2)) was 5.9 times more toxic than benzyl benzoate (11.69 ?g/cm(2)), followed by 2-isopropyl-5-methyl-1,4-benzoquinone (3.29 ?g/cm(2)), and 2,3-dimethoxy-5-methyl-1,4-benzoquinone (5.03 ?g/cm(2)) against T. putrescentiae in the fumigant bioassay. In a filter paper bioassay, the acaricidal activity of 1,4-benzoquinone (0.07 ?g/cm(2)) was 120.1 times more effective than that of benzyl benzoate (8.41 ?g/cm(2)), followed by 2-isopropyl-5-methyl-1,4-benzoquinone (0.11 ?g/cm(2)) and 2,3-dimethoxy-5-methyl-1,4-benzoquinone (0.30 ?g/cm(2)) against T. putrescentiae. These results demonstrate that P. ussuriensis fruit-derived material and its derivatives have potential as new preventive agents for the control of stored food mites. PMID:22980009

Jeon, Ju-Hyun; Yang, Ji-Yeon; Lee, Hoi-Seon

2012-07-01

85

Dementia-specific risks of scabies: Retrospective epidemiologic analysis of an unveiled nosocomial outbreak in Japan from 1989–90  

Microsoft Academic Search

BACKGROUND: Although senile dementia patients in long-term care facilities are at leading risk of scabies, the epidemiologic characteristics of this disease have yet to be fully clarified. This study documents the findings of a ward-scale nosocomial outbreak in western Japan from 1989–90, for which permission to publish was only recently obtained. METHODS: A retrospective epidemiologic study was performed to identify

Masae Tsutsumi; Hiroshi Nishiura; Toshio Kobayashi

2005-01-01

86

Acaricidal activities of apiol and its derivatives from Petroselinum sativum seeds against Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Tyrophagus putrescentiae.  

PubMed

The acaricidal effects of an active constituent derived from Petroselinum sativum seeds and its derivatives were determined using impregnated fabric disk bioassay against Dermatophagoides farinae , Dermatophagoides pteronyssinus , and Tyrophagus putrescentiae and compared with that of synthetic acaricide. The acaricidal constituent of P. sativum was isolated by various chromatographic techniques and identified as apiol. On the basis of LD(50) values against D. farinae and D. pteronyssinus, apiol (0.81 and 0.94 ?g/cm(2)) was 12.4 and 10.2 times more toxic than benzyl benzoate (10.0 and 9.58 ?g/cm(2)), respectively. In acaricidal studies of apiol derivatives, 3,4-methylenedioxybenzonitrile (0.04, 0.03, and 0.59 ?g/cm(2)) was 250, 319, and 20.7 times more toxic than benzyl benzoate (10.0, 9.58, and 12.2 ?g/cm(2)) against D. farinae, D. pteronyssinus, and T. putrescentiae. In structure-activity relationships, the acaricidal activities of apiol derivatives could be related to allyl (-C(3)H(5)) and methoxy (-OCH(3)) functional groups. Furthermore, apiol and its derivatives could be useful for natural acaricides against these three mite species. PMID:21688847

Song, Ha Yun; Yang, Ji Yeon; Suh, Joo Won; Lee, Hoi Seon

2011-07-27

87

The potential of middle eastern flora as a source of new safe bio-acaricides to control Tetranychus cinnabarinus , the carmine spider mite  

Microsoft Academic Search

Twenty-nine plant extracts of local species were evaluated for their potential as a source of bioactive ingredients with significant\\u000a acaricidal activity that could lead to the development of new and safe bio-acaricides. The crude extracts (70% ethanol) of\\u000a these plants were tested for their acaricidal activity against the carmine spider miteTetranychus cinnabarinus in a bioassay under controlled conditions. Mortality, repellency,

F. Mansour; H. Azaizeh; B. Saad; Y. Tadmor; F. Abo-Moch; O. Said

2004-01-01

88

Factors that influence the prevalence of acaricide resistance and tick-borne diseases  

Microsoft Academic Search

This manuscript provides a summary of the results presented at a symposium organized to accumulate information on factors that influence the prevalence of acaricide resistance and tick-borne diseases. This symposium was part of the 19th International Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP), held in New Orleans, LA, USA, during August 10–14, 2003. Populations of

L. D. Foil; P. Coleman; M. Eisler; H. Fragoso-Sanchez; Z. Garcia-Vazquez; F. D. Guerrero; N. N. Jonsson; I. G. Langstaff; A. Y. Li; N. Machila; R. J. Miller; J. Morton; J. H. Pruett; S. Torr

2004-01-01

89

Comparative toxicity of acaricides to Tetranychus merganser Boudreaux and Tetranychus kanzawai Kishida (Acari: Tetranychidae)  

Microsoft Academic Search

Laboratory bioassays were conducted to determine the toxicity of different acaricides against two strains of Tetranychus merganser Boudreaux and two strains of Tetranychus kanzawai Kishida by probit analysis. The 50% lethal concentration (LC50) value and resistance ratio of the probit-concentration regression was considered to determine the resistance. A laboratory selected susceptible strain of T. kanzawai (Tk-JN) was used to compare

M. S. Ullah; D. Moriya; M. Kongchuensin; P. Konvipasruang; T. Gotoh

2011-01-01

90

Acaricidal activity of different extracts from Syzygium cumini L. Skeels (Pomposia) against Tetranychus urticae Koch  

PubMed Central

Objective To investigate the acaricidal activity of different extracts from Syzygium cumini (S. cumini) (Pomposia) againsst Tetranychus urticae Koch (T. urticae) and the biochemical changes in antioxidants enzymes. Methods Six extracts of S. cumini (Pomposia) at concentrations of 75, 150 and 300µg/mL were used to control T. urticae (Koch). Results The ethanol extract showed the most efficient acaricidal activity agent against T. urticae (98.5%) followed by hexane extract (94.0%), ether and ethyl acetate extract (90.0%). The LC50 values of the promising extract were 85.0, 101.0, 102.0 and 98.0µg/mL, respectively. The activities of enzymes including ascorbate peroxidase (APX), peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) in susceptible mites were increased. The activities of all antioxidant enzymes reach the maximum value in mites at LC50 with ethanol and ethyl acetate extracts, respectively. Conclusions The extract of S. cumini has acaricidal acivity against T. urticae, and the ethanol extract is the most efficient. PMID:23569793

Afify, Abd El-Moneim MR; El-Beltagi, Hossam S; Fayed, Sayed A; Shalaby, Emad A

2011-01-01

91

Management of Tetranychus urticae (Acari: Tetranychidae) in strawberry fields with Neoseiulus californicus (Acari: Phytoseiidae) and acaricides.  

PubMed

The purpose of this study was to evaluate the performance of Neoseiulus californicus (McGregor) for the control of Tetranychus urticae Koch in commercial strawberry fields, under greenhouse conditions, in association or not with the use of acaricides. The N. californicus strain used in this study was tolerant or resistant to several pesticides. Three experiments were carried out in the State of São Paulo, Brazil. For the first experiment, the initial infestation of T. urticae was 87.1 active stages per leaflet. Two applications of propargite were made on the first and the 14th day of the experiment. Approximately 2 h after each propargite application, N. californicus was released at a rate of 3.0 and 1.9 adult mites per plant, respectively, for each application. The population of T. urticae decreased from 87.1 to 2.8 mites per leaflet in the first three weeks. After this period, the population of T. urticae was maintained at low levels (acaricide chorfenapyr was applied on the strawberry field. The release of N. californicus (2 mites per plant) was made 2 weeks after spraying the acaricide. The population of T. urticae was maintained at low levels (acaricide application, were not sufficient to reduce significantly the T. urticae population in release plots (release plants + non-release plants) in 6 weeks from the first release, however, the spider mite population decreased from 55.5 to 7.8 active stages per leaflet on release plants, during this period. Interplant dispersal of N. californicus was low in this strawberry field with high infestation of T. urticae. The studies indicate the viability of the use of this strain of N. californicus for the control of T. urticae in strawberry fields under greenhouse conditions, especially in association with selective acaricides. PMID:17549586

Sato, Mário Eidi; Da Silva, Marcos Zatti; De Souza Filho, Miguel Francisco; Matioli, André Luís; Raga, Adalton

2007-01-01

92

Evaluation of safety and efficacy of acaricides for control of the African tortoise tick (Amblyomma marmoreum) on leopard tortoises (Geochelone pardalis).  

PubMed

Nine acaricides (amitraz, carbaryl, chlorpyrifos, cyfluthrin, fipronil, lindane, permethrin, phenothrin, and pyrethrins) were studied for their efficacy in killing the African tortoise tick (Amblyomma marmoreum). Only four of the acaricides (chlorpyrifos, cyfluthrin, lindane, and permethrin) produced 100% mortality within 24 hr of application, and only two (cyfluthrin and permethrin) continued to cause 100% mortality when diluted to as low as 1:10,000. Five of the acaricides (amitraz, carbaryl, chlorpyrifos, cyfluthrin, and permethrin) were studied for toxicity to the leopard tortoise (Geochelone pardalis), the most common host of A. marmoreum. The results indicate that cyfluthrin and permethrin, which were herein found to be the two most effective acaricides for control of A. marmoreum, are also the safest acaricides for use on leopard tortoises. PMID:12216793

Burridge, Michael J; Peter, Trevor F; Allan, Sandra A; Mahan, Suman M

2002-03-01

93

Acaricidal activity of Swietenia mahogani and Swietenia macrophylla ethanolic extracts against Varroa destructor in honeybee colonies.  

PubMed

The acaricidal (miticidal) activity of 90% ethanolic extracts of leaves and stem bark of Swietenia mahogani and Swietenia macrophylla were tested against Varroa destructor mite. Four concentrations were used over two different time intervals under laboratory and field conditions. In general, it was noticed that the acaricidal effect based on mortality and LC(50) of all tested extracts against the Varroa mite was concentration and time dependant. The acaricidal action against Varroa mites was relatively the least for the S. macrophylla stem bark extract at 500 ppm concentration after 48 h while it reached 100% and 95% in case of S. mahogani bark and S. macrophylla leaves, respectively. The% infestation with Varroa in colonies treated with the different extracts at various time intervals showed that the rate of infestation decreased to 0.0% after 12 days from the beginning of treatments with 500 ppm of S. mahogani leaves extract compared to 0.79% decrease after treatment with Mitac, a reference drug (60 mg/colony). The rate of infestation in case of treatments with S. mahogani bark, S. macrophylla leaves and S. macrophylla bark was decreased to 0.11%, 2.41% and 1.08%, respectively. The highest reduction was observed with S. mahogani leaves extract followed by S. mahogani bark. All the tested extracts showed less or no effect on honey bees at the different concentrations and at different bioassay times. This study suggested that the use of natural plant extracts or their products as ecofriendly biodegradable agents could be of high value for the control of Varroa mite. PMID:22101075

El Zalabani, Soheir M; El-Askary, Hesham I; Mousa, Ola M; Issa, Marwa Y; Zaitoun, Ahmed A; Abdel-Sattar, Essam

2012-02-01

94

[Compatibility of two fungal biocontrol agents conidia with commercial chemical acaricides].  

PubMed

In this paper, the biological compatibility of fungal biocontrol agents Beauveria bassiana and Paecilomyces fumosoroseus conidia with 10 commercial chemical acaricides were assayed, based on the conidial germination rates in nutritional liquid and on SDAY plate. The results showed that nutritional liquid was more available than SDAY plate in the assay. So far as the 24 h conidial viability concerned, there were significant differences among the test acaricides with the concentrations of recommended for field spray and 5 and 10 fold dilutions, as well as between the two fungal agents. Since acaricides azocyclotin, liuyangmycin, dicofol and avermectin had strong inhibitory effects on the 24 h germination rate of both fungal agents conidia, their combined application with fungal agents was unsuitable for mite control. However, the combined application of pyridaben, propargite, chlorpyrifos, hexythiazox or amitraz with either B. bassiana or P. fumosoroseus was practical, because of their short-term compatibility. When the mixtures of oil-based B. bassiana formulation with the three concentrations of pyridaben, propargite and chlorpyrifos were stored at 4 degrees C or at ambient temperature for 12 months, none of the three chemicals was considered to be good enough for a combined formulation due to the great variability in long-term compatibility. Nevertheless, chlorpyrifos exhibited an encouraging long-term compatibility with B. bassiana, because its low concentration in the fungal formulation did not affect the conidial viability during a 6.5-month period of storage at ambient temperature. When stored at 4 degrees C in dark, the B. bassiana formulation containing low or medium concentration of chlorpyrifos retained the conidial viability of > 90% for up to 12 months. PMID:17044504

Jiang, Yu; Feng, Mingguang

2006-07-01

95

Acaricidal activities against house dust mites of spearmint oil and its constituents.  

PubMed

The aim of this study was to evaluate the acaricidal activities of spearmint oil and carvone derivatives against house dust mites using contact and fumigant toxicity bioassays to replace benzyl benzoate as a synthetic acaricide. Based on the LD50 values, the contact toxicity bioassay revealed that dihydrocarvone (0.95 and 0.88?µg/cm2) was 7.7 and 6.8 times more toxic than benzyl benzoate (7.33 and 6.01?µg/cm2) against Dermatophagoides farinae and Dermatophagoides pteronyssinus, respectively, followed by carvone (3.78 and 3.23?µg/cm2), spearmint oil (5.16 and 4.64?µg/cm2), carveol (6.00 and 5.80?µg/cm2), and dihydrocarveol (8.23 and 7.10?µg/cm2). Results of the fumigant toxicity bioassay showed that dihydrocarvone (2.73 and 2.16?µg/cm2) was approximately 4.0 and 4.8 times more effective than benzyl benzoate (11.00 and 10.27?µg/cm2), followed by carvone (6.63 and 5.78?µg/cm2), carveol (7.58 and 7.24?µg/cm2), spearmint oil (9.55 and 8.10?µg/cm2), and dihydrocarveol (9.79 and 8.14?µg/cm2). Taken together, spearmint oil and carvone derivatives are a likely viable alternative to synthetic acaricides for managing house dust mites. PMID:24488719

Yang, Ji-Yeon; Kim, Min-Gi; Lee, Sung-Eun; Lee, Hoi-Seon

2014-02-01

96

Direct effect of acaricides on pathogen loads and gene expression levels in honey bees Apis mellifera.  

PubMed

The effect of using acaricides to control varroa mites has long been a concern to the beekeeping industry due to unintended negative impacts on honey bee health. Irregular ontogenesis, suppression of immune defenses, and impairment of normal behavior have been linked to pesticide use. External stressors, including parasites and the pathogens they vector, can confound studies on the effects of pesticides on the metabolism of honey bees. This is the case of Varroa destructor, a mite that negatively affects honey bee health on many levels, from direct parasitism, which diminishes honey bee productivity, to vectoring and/or activating other pathogens, including many viruses. Here we present a gene expression profile comprising genes acting on diverse metabolic levels (detoxification, immunity, and development) in a honey bee population that lacks the influence of varroa mites. We present data for hives treated with five different acaricides; Apiguard (thymol), Apistan (tau-fluvalinate), Checkmite (coumaphos), Miteaway (formic acid) and ApiVar (amitraz). The results indicate that thymol, coumaphos and formic acid are able to alter some metabolic responses. These include detoxification gene expression pathways, components of the immune system responsible for cellular response and the c-Jun amino-terminal kinase (JNK) pathway, and developmental genes. These could potentially interfere with the health of individual honey bees and entire colonies. PMID:22212860

Boncristiani, Humberto; Underwood, Robyn; Schwarz, Ryan; Evans, Jay D; Pettis, Jeffery; vanEngelsdorp, Dennis

2012-05-01

97

Propolis volatiles characterisation from acaricide-treated and -untreated beehives maintained at Algarve (Portugal).  

PubMed

The variability of the volatile profile of 70 propolis samples from acaricide-treated and -untreated beehives maintained at Algarve (Portugal) was evaluated. Propolis samples were collected in three regions of Algarve at three different periods. Cluster analysis based on the propolis volatiles' chemical composition defined two main clusters, not related to the time of year, collection site, altitude, temperature or humidity ranges, and was based mainly on the relative amounts of viridiflorol, n-tricosane and n-nonadecane for cluster I. Cluster II was mainly characterised by the high thymol content, followed by viridiflorol, n-tricosane and n-nonadecane. The presence of higher thymol levels in propolis samples from cluster II may reflect the long use of an acaricide with thymol as main active ingredient. All samples showed an intense rock-rose aroma supported by the presence of characteristic Cistus and labdanum oil volatile components. Given the nowadays frequent propolis household use, volatiles thorough characterisation may assist in its quality assessment. PMID:22724515

Miguel, Maria G; Nunes, Susana; Cruz, Cláudia; Duarte, João; Antunes, Maria D; Cavaco, Ana M; Mendes, Marta D; Lima, A Sofia; Pedro, Luis G; Barroso, José G; Figueiredo, A Cristina

2013-04-01

98

A model to test how ticks and louping ill virus can be controlled by treating red grouse with acaricide.  

PubMed

Ticks are the most important vectors of disease-causing pathogens in Europe. In the U.K., Ixodes ricinus L. (Ixodida: Ixodidae) transmits louping ill virus (LIV; Flaviviridae), which kills livestock and red grouse, Lagopus lagopus scoticus Lath. (Galliformes: Phasianidae), a valuable game bird. Tick burdens on grouse have been increasing. One novel method to reduce ticks and LIV in grouse may be acaricide treatment. Here, we use a mathematical model parameterized with empirical data to investigate how the acaricide treatment of grouse might theoretically control ticks and LIV in grouse. Assuming a situation in which ticks and LIV impact on the grouse population, the model predicts that grouse density will depend on deer density because deer maintain the tick population. In low deer densities, no acaricide treatment is predicted to be necessary because abundances of grouse will be high. However, at higher deer densities, the model predicts that grouse densities will increase only if high numbers of grouse are treated, and the efficacy of acaricide is high and lasts 20 weeks. The qualitative model predictions may help to guide decisions on whether to treat grouse or cull deer depending on deer densities and how many grouse can be treated. The model is discussed in terms of practical management implications. PMID:23088727

Porter, R; Norman, R A; Gilbert, L

2013-09-01

99

In vitro acaricidal efficacy of plant extracts from Brazilian flora and isolated substances against Rhipicephalus microplus (Acari: Ixodidae).  

PubMed

The tick Rhipicephalus microplus causes significant losses in livestock cattle and has developed increasing resistance to the primary acaricides that are used to treat these infections. The objective of this study was to identify new biomolecules or isolated substances showing acaricidal activity from plants. Larval packet tests were conducted to evaluate the effects of 11 species of plants and three isolated substances (betulinic acid, eugenol, and nerolidol) on R. microplus. An adult female immersion test was performed with the substance that showed the highest larvicidal activity, which was evaluated for inhibition of reproduction. Tests using Licania tomentosa, Hymenaea stigonocarpa, Hymenaea courbaril, Stryphnodendron obovatum, Jacaranda cuspidifolia, Jacaranda ulei, Struthanthus polyrhizus, Chrysobalanus icaco, Vernonia phosphorea, Duguetia furfuracea, and Simarouba versicolor extracts as well as the isolated substance betulinic acid indicated lower acaricidal effects on R. microplus larvae. The extract displaying the best larvicidal activity was the ethanolic extract from L. tomentosa at a concentration of 60%, resulting in a mortality rate of 40.3%. However, nerolidol and eugenol showed larvicidal activity, which was highest for eugenol. Nerolidol caused a 96.5% mortality rate in the R. microplus larvae at a high concentration of 30%, and eugenol caused 100% mortality at a concentration of 0.3%. In the adult immersion test, 5% eugenol was identified as a good biomolecule for controlling R. microplus, as demonstrated by its high acaricidal activity and inhibition of oviposition. PMID:24221889

Valente, Paula Pimentel; Amorim, Juliana Mendes; Castilho, Rachel Oliveira; Leite, Romário Cerqueira; Ribeiro, Múcio Flávio Barbosa

2014-01-01

100

Characterization, mode of action, and efficacy of twelve silica-based acaricides against poultry red mite (Dermanyssus gallinae) in vitro.  

PubMed

Poultry red mite infestation still is an unsolved problem in poultry farms. Legal regulations, residue risks, and resistances limit chemical control of mites. Alternatives to chemical acaricides for control of poultry red mite are silica-based products, which have as a main constituent silicon dioxide. The acaricidal effect is attributed to sorptive properties of the particles, which result in the mite's death by desiccation. In the present study, the acaricidal efficacy of 12 products containing natural or synthetic silica, 9 in powder form, and 3 for liquid application was tested under laboratory conditions. Mite mortality was measured at several intervals and the mean lethal time (LT??) determined by Probit analysis after Abbott's correction. The LT?? values of the products significantly differed (Tukey's HSD p?acaricidal efficacy. Influence of these parameters on acaricidal efficacy was significant according to the results of a stepwise regression analysis (p?

Schulz, Johanna; Berk, Jutta; Suhl, Johanna; Schrader, Lars; Kaufhold, Stefan; Mewis, Inga; Hafez, Hafez Mohammed; Ulrichs, Christian

2014-09-01

101

Action of the insect growth regulator fluazuron, the active ingredient of the acaricide Acatak®, in Rhipicephalus sanguineus nymphs (Latreille, 1806) (Acari: Ixodidae).  

PubMed

The present study evaluated the efficacy of fluazuron (active ingredient of the acaricide Acatak®) and its effects on Rhipicephalus sanguineus nymphs fed on rabbits exposed to different doses of this insect growth regulator. Three different doses of fluazuron (20 mg/kg, 40 mg/kg, and 80 mg/kg) were applied on the back of hosts (via "pour on"), while distilled water was applied to the Control group. On the first day of treatment with fluazuron (24 h), hosts were artificially infested with R. sanguineus nymphs. Once fully engorged, nymphs were removed and placed in identified Petri dishes in Biochemical Oxygen Demand (BOD) incubator for 7 days. After this period, engorged nymphs were processed for ultramorphological analysis. The results revealed alterations in the ultramorphology of many chitinous structures (smaller hypostome and chelicerae, less sclerotized scutum, fewer sensilla, fewer pores, absence of grooves, marginal and cervical strips and festoons in the body, even the anal plaque was damaged) that play essential roles for the survivor of ticks and that can compromise the total or partial development of nymphs and emergence of adults after periodic molting. Our findings confirm the efficacy of fluazuron, a more specific and less aggressive chemical to the environment and human health, and that does not induce resistance, in nymphs of the tick R. sanguineus in artificially infested rabbits treated with this arthropod growth regulator (AGR), indicating that it could be used in the control of this stage of the biological cycle of the tick R. sanguineus. PMID:24000046

Calligaris, Izabela Braggião; De Oliveira, Patricia Rosa; Roma, Gislaine Cristina; Bechara, Gervásio Henrique; Camargo-Mathias, Maria Izabel

2013-11-01

102

Acaricidal and repellent activity of terpenoids from seaweeds Collected in Pernambuco, Brazil.  

PubMed

n-Hexane and dichloromethane extracts obtained from Laurencia dentroidea (Rhodophyta) and Canistrocarpus cervicornis (Phaeophyta) were investigated for their acaricidal and repellent properties against Tetranychus urticae under laboratory conditions. The two extracts displayed moderate toxicity and good repellent proprieties, and were significantly more toxic (36-fold) than the positive control (eugenol), whereas eugenol was tenfold more repellent than either seaweed extract. The sesquiterpenoid elatol (1) was isolated from L. dentroidea and the diterpenoid seco-dolastane (4R,9S,14S)-4alpha-acetoxy-9beta, 14alpha-dihydroxydolast-1(15),7-diene (2) from C. cervicornis, the chemical structures of which were characterized by NMR spectroscopic data (1H and 13C) and by comparison with literature data. These compounds exhibited moderate toxicity, but a high degree of repellent activity against T. urticae. The findings suggest that marine natural products, specifically terpenes, can be employed for the development of new pesticides and become prototype agrochemical agents. PMID:22574442

Born, Flávia Souza; Bianco, Everson Miguel; da Camara, Claudio Augusto Gomes

2012-04-01

103

Acaricidal properties of the essential oil from Zanthoxylum caribaeum against Rhipicephalus microplus.  

PubMed

Zanthoxylum caribaeum Lamarck (Rutaceae) is plant species with a variety of medical applications, including insecticidal activity. This study determined the bioacaricidal activity of the essential oil from Z. caribaeum leaves against engorged Rhipicephalus (Boophilus) microplus (Canestrini, 1887) females using the adult immersion test. For this purpose, three serial concentrations (5.0, 2.5, and 1.25%, vol:vol, in 1% dimetilsulfoxide) of the essential oil were used. Essential oil 5% caused 65% mortality on the first day after treatment, 85% on the second day, and 100% mortality by the fifth day. To our knowledge, this is the first demonstration of the acaricidal activity of the essential oil from Z. caribaeum leaves against cattle ticks. PMID:25276925

Nogueira, Jeane; Vinturelle, Rafaelle; Mattos, Camila; Tietbohl, Luis Armando Candido; Santos, Marcelo Guerra; Junior, Itabajara Silva Vaz; Mourão, Samanta Cardozo; Rocha, Leandro; Folly, Evelize

2014-09-01

104

Efficacy of pheromone-acaricide-impregnated tail-tag decoys for controlling the bont tick,Amblyomma hebraeum (Acari: Ixodidae), on cattle in Zimbabwe  

Microsoft Academic Search

A large-scale field test using pheromone-acaricide-impregnated plastic tail-tag decoys demonstrated excellent efficacy of these devices for control of the bont tick,Amblyomma hebraeum, on cattle in Zimbabwe. The tail tags were impregnated with a mixture containingo-nitrophenol, methyl salicylate, 2,6-dichlorophenol and phenylacetaldehyde and one of three different acaricides (cyfluthrin, flumethrin or alphacypermethrin).o-Nitrophenol and methyl salicylate are components of theA. hebraeum attraction-aggregation-attachment pheromone,

R. A. I. Norval; Daniel E. Sonenshine; Sandra A. Allan; Michael J. Burridge

1996-01-01

105

Acaricidal efficacy of synthesized silver nanoparticles using aqueous leaf extract of Ocimum canum against Hyalomma anatolicum anatolicum and Hyalomma marginatum isaaci (Acari: Ixodidae)  

Microsoft Academic Search

The use of acaricides had limited efficacy in reducing tick infestations and is often accompanied by serious drawbacks, including\\u000a the selection of acaricide resistant ticks, contamination of environment, and milk and meat products with drug residues. The\\u000a present study was based on assessments of the antiparasitic activities to determine the efficacy of synthesized silver nanoparticles\\u000a (AgNPs) utilizing aqueous leaf extract

Chidambaram Jayaseelan; Abdul Abdul Rahuman

106

Acaricidal effect of herbal extracts against cattle tick Rhipicephalus (Boophilus) microplus using in vitro studies.  

PubMed

The crude methanolic extract of Datura stramonium, Azadirachta indica, and Calotropis procera leaves, Allium sativum (AS) cloves, and Carica papaya (CP) seeds collected from Banaskanta, Gujarat (India) was tested for its acaricidal properties against Rhipicephalus (Boophilus) microplus. The percent adult mortality within 15 days, reproductive index, percentage inhibition of oviposition, hatching of laid ova, and percentage larval mortality were studied at concentrations of 12.5, 25, 50, and 100 mg/ml. At the highest concentration (100 mg/ml), the adult tick mortality was 66.67, 73.33, 80.00, and 93.33% for C. procera, D. stramonium, A. sativum, and C. papaya extracts, respectively, and it was statistically significant (P?acaricidal properties and could be a potential component of alternative R. (B.) microplus tick control strategy. PMID:24633906

Shyma, K P; Gupta, J P; Ghosh, S; Patel, K K; Singh, Veer

2014-05-01

107

Acaricidal properties of the formulations based on essential oils from Cymbopogon winterianus and Syzygium aromaticum plants.  

PubMed

The cattle tick, Rhipicephalus (Boophilus) microplus, has caused serious harm to livestock raising in Brazil, considering the costs of controlling it, loss of revenue due to smaller production of milk and meat, and damage to leather, in addition to transmitting diseases. The use of medicinal plants is considered an alternative to the recurring resistance to chemicals. Due to the need for efficient alternatives with less environmental impact, this study aimed to develop contact formulations with essential oils from the Java citronella (Cymbopogon winterianus) and clove (Syzygium aromaticum) plants and to assess in vitro the effects in different stages of the tick cycle. In the present study, concentrations from 0.5-15.0 % of the essential oils incorporated in the formulations were used. The ticks from different geographical areas were treated with those formulations, and their effects on the production levels of eggs, on the larvae hatching, and their efficiency on ticks were assessed. The obtained results were compared with other commercial acaricidal products. After the 20th day of treatment, the formulations with citronella essential oil had 2.09-55.51 % efficiency, depending on the concentration of the oil incorporated. The efficiency of the treatment with formulations containing clove essential oil was higher, from 92.47-100 %. The results showed the acaricidal effects of the formulations tested when compared to commercial chemical products. In vivo studies should be performed in order to assess the efficiency of those formulations in the fields, aiming to use these products as an alternative for controlling cattle ticks. PMID:25199555

de Mello, Valéria; Prata, Márcia Cristina de Azevedo; da Silva, Márcio Roberto; Daemon, Erik; da Silva, Luciane Santos; Guimarães, Flávia Del Gaudio; de Mendonça, Alessandra Esther; Folly, Evelize; Vilela, Fernanda Maria Pinto; do Amaral, Lilian Henriques; Cabral, Lucio Mendes; do Amaral, Maria da Penha Henriques

2014-12-01

108

Determination of synthetic acaricides residues in beeswax by high-performance liquid chromatography with photodiode array detector.  

PubMed

A multiresidue HPLC method for identification and quantification of the synthetic acaricides fluvalinate, coumaphos, bromopropylate and its metabolite 4,4'-dibromobenzophenone in beeswax has been developed. Different techniques were tested and modified. The method consists of a sample preparation with isooctane followed by solid phase extraction using Florisil columns. Determination of the synthetic acaricides is achieved by HPLC with a photodiode array detector. Analytical performance of the proposed method, including sensitivity, accuracy and precision was satisfactory. The LOD for the analytes varied between 0.1 and 0.2 microg g(-1) wax and the recoveries between 70 and 110%. Relative standard deviation of the repeatability of the method is <15% and reproducibility is <31%. PMID:17386431

Adamczyk, Sabine; Lázaro, Regina; Pérez-Arquillué, Consuelo; Herrera, Antonio

2007-01-01

109

Acaricidal activities of some essential oils and their monoterpenoidal constituents against house dust mite, Dermatophagoides pteronyssinus (Acari: Pyroglyphidae)  

PubMed Central

The acaricidal activities of fourteen essential oils and fourteen of their major monoterpenoids were tested against house dust mites Dermatophagoides pteronyssinus. Five concentrations were used over two different time intervals 24 and 48 h under laboratory conditions. In general, it was noticed that the acaricidal effect based on LC 50 of either essential oils or monoterpenoids against the mite was time dependant. The LC 50 values were decreased by increasing of exposure time. Clove, matrecary, chenopodium, rosemary, eucalyptus and caraway oils were shown to have high activity. As for the monoterpenoids, cinnamaldehyde and chlorothymol were found to be the most effective followed by citronellol. This study suggests the use of the essential oils and their major constituents as ecofriendly biodegradable agents for the control of house dust mite, D. pteronyssinus. PMID:17111463

Saad, El-Zemity; Hussien, Rezk; Saher, Farok; Ahmed, Zaitoon

2006-01-01

110

Rotenoid content and in vitro acaricidal activity of Tephrosia vogelii leaf extract on the tick Rhipicephalus appendiculatus.  

PubMed

This study aimed to determine the rotenoid content of leaf extracts of the white (TVW) and purple (TVP) varieties of Tephrosia vogelii, both collected in North-Kivu Province, Democratic Republic of Congo and to evaluate their in vitro acaricidal efficacy on the tick Rhipicephalus appendiculatus. The high performance liquid chromatography analysis of rotenoid compounds from those extracts revealed that the contents of rotenone and deguelin were respectively higher in the leaves of TVW (0.044% and 1.13%) than in TVP (0.014% and 0.66%). Batches of 20 live adult ticks were immersed for 15 min in six different doses of each plant extract (0.625; 1.25; 2.5; 5; 10 and 20mg/mL of distilled water) and in the solution of Milbitraz(®) (12.5%m/v emulsifiable concentrate of amitraz) as a positive control. Additionally 9.5% ethanol and distilled water control groups were included. Tick mortalities were recorded every 24h for 5 days. The results indicated that there was no significant difference (P>0.05) between the acaricidal effect of Milbitraz(®) and the plant material used at a dose of at least 2.5 or 5mg/mL for TVW and TVP respectively. However, the dose response relationship determined at the fifth day after treatment showed a similar acaricidal effect for the two plant varieties with similar lethal dose 50 (LD(50)) of 0.83 and 0.81 mg/mL for TVW and TVP respectively. It is concluded that T. vogelii leaves may be used for the control of R. appendiculatus in areas where synthetic acaricides are either not available or affordable. However, T. vogelii extract should be sprayed in order to limit the potential risks of ecotoxicity linked to rotenoid compounds. PMID:22795670

Kalume, M K; Losson, B; Angenot, L; Tits, M; Wauters, J N; Frédérich, M; Saegerman, C

2012-11-23

111

Acaricidal activity of essential oils from five endemic conifers of New Caledonia on the cattle tick Rhipicephalus (Boophilus) microplus.  

PubMed

The aim of the present study was to demonstrate acaricidal activity on the cattle tick Rhipicephalus (Boophilus) microplus of essential oils from endemic conifers of New Caledonia in the context of the development of natural alternatives. Acaricidal activity of essential oils extracted from resin and heartwood of five endemic conifers of New Caledonia (Araucaria columnaris, Agathis moorei, Agathis ovata, Callitris sulcata, and Neocallitropsis pancheri) was evaluated on 14- to 21-day-old Rhipicephalus microplus tick larvae using the Larval Packal Test bioassay. A first screening with 5% dilute solution was carried out and the oils with 100% of mortality at this rate were diluted until no activity was shown. The heartwood oils of the two Cupressaceae were the most active with LC50 value of 0.65% for C. sulcata and 0.55% for N. pancheri while resin oil of A. columnaris (LC50=1.62%) was the most active of the Araucariaceae family. Negative control (ethanol) was not toxic to the larvae. The chemical composition of essential oil from resin of A. columnaris was analyzed by gas chromatography-mass spectrometry. The essential oil was characterized by high level of sesquiterpene hydrocarbons and oxygenated sesquiterpenes and was composed mainly of aromadendrene (23.1%) and bicyclogermacrene (16.0%). In order to compare different plant resources in a sustainable program of natural acaricide, an "essential oil efficiency EOE" can be measured as the ratio between the yield of extraction and LC50 value. This study shows that A. columnaris (EOE=2.36) and N. pancheri (EOE=3.51) could provide valuable and effective natural acaricides for control of the cattle tick R. microplus. PMID:23371495

Lebouvier, Nicolas; Hue, Thomas; Hnawia, Edouard; Lesaffre, Leïla; Menut, Chantal; Nour, Mohammed

2013-04-01

112

Acaricidal toxicity of 2'-hydroxy-4'-methylacetophenone isolated from Angelicae koreana roots and structure-activity relationships of its derivatives.  

PubMed

The acaricidal activities of 2'-hydroxy-4'-methylacetophenone derived from Angelica koreana roots and its derivatives against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Tyrophagus putrescentiae were examined by vapor phase and contact toxicity bioassays. In the vapor phase toxicity bioassay, 2'-methylacetophenone (1.25 ?g/cm(2)) was 8.0 times more toxic against D. farinae than benzyl benzoate (10.00 ?g/cm(2)), followed by 3'-methylacetophenone (1.26 ?g/cm(2)), 4'-methylacetophenone (1.29 ?g/cm(2)), 2'-hydroxy-4'-methylacetophenone (1.75 ?g/cm(2)), and 2'-hydroxy-5'-methylacetophenone (1.96 ?g/cm(2)). In the contact toxicity bioassay, 3'-methylacetophenone (0.58 ?g/cm(2)) was 17.24 times more effective against D. farinae than benzyl benzoate (7.52 ?g/cm(2)), followed by 2'-methylacetophenone (0.64 ?g/cm(2)), 2'-hydroxy-4'-methylacetophenone (0.76 ?g/cm(2)), 4'-methylacetophenone (0.77 ?g/cm(2)), and 2'-hydroxy-5'-methylacetophenone (1.16 ?g/cm(2)). The acaricidal activities of 2'-hydroxy-4'-methylacetophenone derivatives against D. pteronyssinus and T. putrescentiae were similar to those against D. farinae. In terms of structure-activity relationships, acaricidal activity against the three mite species changed with the introduction of hydroxyl and methyl functional groups onto the acetophenone skeleton. Furthermore, some of 2'-hydroxy-4'-methylacetophenone derivatives could be useful for natural acaricides against three mite species. PMID:22429095

Oh, Min Seok; Yang, Ji-Yeon; Lee, Hoi Seon

2012-04-11

113

Acaricide treatment affects viral dynamics in Varroa destructor-infested honey bee colonies via both host physiology and mite control.  

PubMed

Honey bee (Apis mellifera) colonies are declining, and a number of stressors have been identified that affect, alone or in combination, the health of honey bees. The ectoparasitic mite Varroa destructor, honey bee viruses that are often closely associated with the mite, and pesticides used to control the mite population form a complex system of stressors that may affect honey bee health in different ways. During an acaricide treatment using Apistan (plastic strips coated with tau-fluvalinate), we analyzed the infection dynamics of deformed wing virus (DWV), sacbrood virus (SBV), and black queen cell virus (BQCV) in adult bees, mite-infested pupae, their associated Varroa mites, and uninfested pupae, comparing these to similar samples from untreated control colonies. Titers of DWV increased initially with the onset of the acaricide application and then slightly decreased progressively coinciding with the removal of the Varroa mite infestation. This initial increase in DWV titers suggests a physiological effect of tau-fluvalinate on the host's susceptibility to viral infection. DWV titers in adult bees and uninfested pupae remained higher in treated colonies than in untreated colonies. The titers of SBV and BQCV did not show any direct relationship with mite infestation and showed a variety of possible effects of the acaricide treatment. The results indicate that other factors besides Varroa mite infestation may be important to the development and maintenance of damaging DWV titers in colonies. Possible biochemical explanations for the observed synergistic effects between tau-fluvalinate and virus infections are discussed. PMID:22020517

Locke, Barbara; Forsgren, Eva; Fries, Ingemar; de Miranda, Joachim R

2012-01-01

114

Inhibition of ATP dephosphorylation by acaricides with emphasis on the anti-ATPase activity of the carbodiimide metabolite of diafenthiuron.  

PubMed

3-(2,6-Diisopropyl-4-phenoxyphenyl)-1-tert-butylcarbodiimide (DFCD), a toxic metabolite and photodegradation product of the propesticide diafenthiuron, and dicyclohexylcarbodiimide (DCCD), a commonly used biochemical inhibitory probe, inhibited Mg(2+)-, Na+K(+)-, and Ca2+Mg(2+)-ATPase activities in preparations from bulb mites (Rhizoglyphus echinopus (Fumouze and Robin)), twospotted spider mites (Tetranychus urticae Koch), and bluegill (Lepomis macrochirus Rafinesque) brain. DCCD was more active than DFCD, but neither carbodiimide was very potent. A possible exception occurred with DCCD, which caused 100% inhibition of bulb mite oligomycin-sensitive Mg(2+)-ATPase activity at a concentration of 0.1 mM. Using house fly, Musca domestica L., thorax mitochondrial Mg(2+)-ATPase, we showed that the binding domain for both carbodiimides was in the F0 portion of the enzyme, probably the transmembrane proton channel which is the known site of DCCD binding in proton-translocating ATPases. Certain other specific acaricides were inhibitors (greater than 50% at 0.1 mM) of ATPase preparations from bulb mites. These acaricides included chloropropylate, bromopropylate, oxythioquinox, cyhexatin, and flubenzimine (Mg2+ and Na+K(+)-ATPase), and ovex, chlorbenside, and propargite (Mg(2+)-ATPase). The role of ATPase inhibition in the modes of acaricidal and insecticidal actions of diafenthiuron, the two carbodiimides, and the other compounds is discussed. PMID:1832178

Kadir, H A; Knowles, C O

1991-06-01

115

Acaricidal Activity of Petroleum Ether Extract of Leaves of Tetrastigma leucostaphylum (Dennst.) Alston against Rhipicephalus (Boophilus) annulatus  

PubMed Central

The acaricidal activity of the petroleum ether extract of leaves of Tetrastigma leucostaphylum (Dennst.) Alston (family: Vitaceae) against Rhipicephalus (Boophilus) annulatus was assessed using adult immersion test (AIT). The per cent of adult mortality, inhibition of fecundity, and blocking of hatching of eggs were studied at different concentrations. The extract at 10% concentration showed 88.96% inhibition of fecundity, 58.32% of adult tick mortality, and 50% inhibition of hatching. Peak mortality rate was observed after day 5 of treatment. Mortality of engorged female ticks, inhibition of fecundity, and hatching of eggs were concentration dependent. The LC50 value of the extract against R. (B.) annulatus was 10.46%. The HPTLC profiling of the petroleum ether extract revealed the presence of at least seven polyvalent components. In the petroleum ether extract, nicotine was identified as one of the components up to a concentration of 5.4%. However, nicotine did not reveal any acaricidal activity up to 20000 ppm (2%). Coconut oil, used as diluent for dissolving the extract, did not reveal any acaricidal effects. The results are indicative of the involvement of synergistic or additive action of the bioactive components in the tick mortality and inhibition of the oviposition.

Krishna, T. P. Adarsh; Krishna, T. P. Ajeesh; Chithra, N. D.; Deepa, P. E.; Darsana, U.; Sreelekha, K. P.; Juliet, Sanis; Nair, Suresh N.; Ajith Kumar, K. G.; Ghosh, Srikanta

2014-01-01

116

Management of lone star ticks (Acari: Ixodidae) in recreational areas with acaricide applications, vegetative management, and exclusion of white-tailed deer.  

PubMed

A project on management of lone star ticks, Amblyomma americanum (L.), at Land Between the Lakes, a Tennessee Valley Authority recreational area in Kentucky-Tennessee, during 1984-1988, demonstrated the effectiveness and economics of three control technologies. Acaricide applications (chlorpyrifos at 0.28 kg [AI]/ha), vegetative management (mowing and removal of 40% overstory and 90-100% of midstory, understory, and leaf litter), and host management (white-tailed deer exclusion from a 71-ha campground with a single-line fence) provided 75, 70, and 64% mean controls of all life stages of the lone star tick, respectively. Combinations of acaricide applications + vegetative management, acaricide applications + host management, and acaricide applications + vegetative management + host management produced 94, 89, and 96% mean control of all life stages, respectively. The costs of acaricide applications (two per year), vegetative management (two mowings per year), and white-tailed deer exclusion (single-line fence) were $45, $150, and $30/ha/yr, respectively. Results of this project are used to design management strategies that could be considered for use against lone star ticks in recreational areas. PMID:1696994

Bloemer, S R; Mount, G A; Morris, T A; Zimmerman, R H; Barnard, D R; Snoddy, E L

1990-07-01

117

Acaricidal activity of ethanolic extract of Artemisia absinthium against Hyalomma anatolicum ticks.  

PubMed

The aim of the study was to evaluate the in vitro efficacy of different concentrations of ethanolic extract obtained from the aerial parts of Artemisia absinthium in comparison to amitraz on adults, eggs and larvae of Hyalomma anatolicum using the adult immersion test (AIT), egg hatchability test and larval packet test (LPT), respectively. Four concentrations of the extract (2.5, 5, 10 and 20 %) with three replications for each concentration were used in all the bioassays. In AIT, the mortality rates at 2.5, 5 and 10 % were significantly different (p < 0.05) in comparison to the control group; however, at 20 %, it was similar to the positive control group. Maximum mortality of 86.7 % was recorded at 20 %. The LC50 and LC95 values were calculated as 6.51 and 55.43 %, respectively. The oviposition was reduced significantly by 36.8 and 59.1 % at concentrations of 10 and 20 %, respectively. Egg hatchability was reduced significantly at all concentrations (2.5-20 %) in comparison to the control. In LPT, the extract caused 100 % mortality of larvae at all the concentrations after 24 h. The results show that ethanolic extract obtained from the aerial parts of A. absinthium has acaricidal properties and could be useful in controlling H. anatolicum. PMID:25039005

Godara, R; Parveen, S; Katoch, R; Yadav, A; Katoch, M; Khajuria, J K; Kaur, D; Ganai, A; Verma, P K; Khajuria, Varun; Singh, N K

2015-01-01

118

Acaricides and predatory mites against the begonia mite, Polyphagotarsonemus latus (Acari: Tarsonemidae), on Hedera helix.  

PubMed

In recent years, the begonia mite (Polyphagotarsonemus lotus) has become an important threat to different ornamental cultures in warm greenhouses. At present there are no professional plant protection products registered in Belgium for the control of mites of the Tarsonemidae family. In a screening trial, we evaluated the efficacy of a range of different acaricides: abamectin, milbemectin, pyridaben, spirodiclofen. Based on the results of the screening trial several products were selected for a full efficacy trial following EPPO guidelines. The best control results were obtained with two products from the avermectine group: abamectin and milbemectin. As growers currently have to rely solely on the use of natural enemies there is a strong need for practical evaluation of efficacies of the various predatory mite species (Amblyseius swirskii, A. cucumeris, A. andersoni) used in biological mite control. In a series of experiments, we screened the use of different species of predatory mites. The first efficacy trials on heavily infested plants at different rates of dosage and under different circumstances (temperature, dose rate, application technique) were started in May 2008. In these experiments Amblyseius swirskii showed good efficacy. But temperature was the limiting factor: the predatory mite needed a minimal temperature of 18 degrees C to obtain good results. Further research is necessary to search for predatory mites that can be used in winter conditions (lower temperatures, less light). PMID:20218530

Audenaert, Joachim; Vissers, Marc; Haleydt, Bart; Verhoeven, Ruth; Goossens, Frans; Gobin, Bruno

2009-01-01

119

Development of acaricide resistance in Pacific spider mite (Tetranychus pacificus) from California vineyards.  

PubMed

In recent years, grape growers in California reported failures of acaricides against Tetranychus pacificus McGregor. We collected T. pacificus populations from four vineyards and tested them for resistance to bifenazate, propargite and pyridaben. In addition, we sequenced part of the cytochrome b gene of bifenazate-resistant and -susceptible T. pacificus to test for the presence of mutations reported to confer resistance to the congeneric T. urticae. None of the mutations conferring resistance to bifenazate in T. urticae were present in resistant T. pacificus. Resistance levels ranged from full susceptibility to statistically significant 11-fold resistance to pyridaben, sevenfold resistance to bifenazate and fourfold resistance to propargite compared to a susceptible population. Despite the relatively low levels of resistance detected, we estimated that under the conditions of our study the highest field rates of bifenazate and pyridaben application would cause less than 58 and 66% mortality of adult females in the most resistant populations, respectively. In contrast, field rates of propargite application would cause close to 100% mortality in the least susceptible population. These results highlight a potential link between resistance development and reduced field effectiveness for bifenazate and pyridaben. Finally, T. pacificus may be more tolerant to bifenazate and propargite than T. urticae, since the LC(50) values for the susceptible population of T. pacificus were several times higher than LC(50)'s reported for susceptible T. urticae. PMID:19771398

Stavrinides, Menelaos C; Van Nieuwenhuyse, Pieter; Van Leeuwen, Thomas; Mills, Nicholas J

2010-03-01

120

Acaricidal activity and repellency of essential oil from Piper aduncum and its components against Tetranychus urticae.  

PubMed

The chemical composition of essential oil of leaves of Piper aduncum L., growing wild in a fragment of the Atlantic Rainforest biome in northeastern Brazil, was determined through gas chromatography-mass spectrometry. The acaricidal activity and repellency of the essential oil and its components [dillapiole (0.28 g/ml), ?-humulene (0.016 g/ml), (E)-nerolidol (0.0007 g/ml) and ?-caryophyllene (0.0021 g/ml)] were evaluated in the laboratory against adults of Tetranychus urticae Koch. The mites were more susceptible to the oil in fumigation tests (LC(50) = 0.01 ?l/l of air) than in contact test with closed Petri dish (LC(50) = 7.17 ?l/ml); mortality was reduced by approximately 50 % in the latter test. The repellent action of the oil and toxicity by fumigation and contact did not differ significantly from the positive control (eugenol). The repellent activity was attributed to the components (E)-nerolidol, ?-humulene and ?-caryophyllene, whereas toxicity by fumigation and contact was attributed to ?-caryophyllene. The effect of Piper oil and the role of its components regarding host plant preference with a two-choice leaf disk test are also discussed. PMID:22415244

Araújo, Mário J C; Câmara, Cláudio A G; Born, Flávia S; Moraes, Marcílio M; Badji, César A

2012-06-01

121

Acaricidal activity of Cymbopogon citratus and Azadirachta indica against house dust mites  

PubMed Central

Objective To examine the acaricidal effects of the essential oil of Cymbopogon citratus leaf extract (lemongrass) and ethanolic Azadirachta indica leaf extract (neem) against house dust mites Dermatophagoides farinae (D. farinae) and Dermatophagoides pteronyssinus (D. pteronyssinus). Methods Twenty-five adults mites were placed onto treated filter paper that is soaked with plant extract and been tested at different concentrations (50.00%, 25.00%, 12.50%, 6.25% and 3.13%) and exposure times (24hrs, 48hrs, 72hrs and 96 hrs). All treatments were replicated 7 times, and the experiment repeated once. The topical and contact activities of the two herbs were investigated. Results Mortalities from lemongrass extract were higher than neem for both topical and contact activities. At 50 % concentration, both 24 hrs topical and contact exposures to lemongrass resulted in more than 91% mortalities for both species of mites. At the same concentration and exposure time, neem resulted in topical mortalities of 40.3% and 15.7% against D. pteronyssinus and D. farinae respectively; contact mortalities were 8.0% and 8.9% against the 2 mites, respectively. There was no difference in topical mortalities of D. pteronyssinus from exposure to concentrations of lemongrass and neem up to 12.50%; lemongrass was more effective than neem at the higher concentrations. Conclusions Generally, topical mortalities of D. farinae due to lemongrass are higher than that due to neem. Contact mortalities of lemongrass are always higher that neem against both species of mites. PMID:23569794

Hanifah, Azima Laili; Awang, Siti Hazar; Ming, Ho Tze; Abidin, Suhaili Zainal; Omar, Maizatul Hashima

2011-01-01

122

Toxicity and efficacy of selected pesticides and new acaricides to stored product mites (Acari: Acaridida).  

PubMed

Stored product mites can often infest stored products, but currently there is little information regarding the efficacy of pesticides that can be used for control. In this study we evaluated several common pesticides formulated from single active ingredients (a.i.) or commercially available mixtures (chlorpyrifos, deltamethrin, beta-cyfluthrin, and a combination of deltamethrin and S-bioallethrin), plus an acaricide composed of permethrin, pyriproxyfen and benzyl benzolate, for efficacy against Acarus siro, Tyrophagus putrescentiae, and Aleuroglyphus ovatus. The pesticides were incorporated into the mite diets in a dose range of 10-1000 microg a.i. g(-1) diet. Concentrations for suppression of 50 and 90% population growth and eradication (rC0) of mites were fit to linear regression models. None of the tested pesticides gave complete eradication of A. siro, which was the most tolerant of the three mite species tested. The most effective pesticide Allergoff 175 CS was a combination product (a nano-capsule suspension of permethrin, pyriproxyfen and benzyl benzolate) labeled for dust mites, with rC0 range of 463-2453 microg a.i. (permethrin) g(-1) diet depending on the species. Least effective were chlorpyrifos and deltamethrin. PMID:17674127

Hubert, Jan; Stejskal, Vaclav; Munzbergova, Zuzana; Hajslova, Jana; Arthur, Frank H

2007-01-01

123

Spectroscopic evaluation of thymol dissolved by different methods and influence on acaricidal activity against larvae of Rhipicephalus microplus (Acari: Ixodidae).  

PubMed

The acaricidal activity of three thymol formulations was investigated at five concentrations (1.25, 2.5, 5.0, 7.5, and 10.0 mg/ml) on Rhipicephalus microplus larvae, and the behavior of its solubility in these formulations was analyzed. The thymol was dissolved in distilled water plus 1 % dimethylsulfoxide as adjuvant under two heating regimes (water bath in formulation 1 and hot plate in formulation 2) as well as without heating in 50 % ethanol and 50 % water (v/v). The acaricidal activity was assessed by the modified larval packet test, and the solubilization behavior was investigated by ultraviolet-visible spectroscopy, based on the Beer-Lambert law. With formulations 1 and 2, the mortality was greater than 95 % starting at the thymol concentrations of 5.0 and 7.5 mg/ml, respectively, while with formulation 3, this mortality level was reached starting at a concentration of 2.5 mg/ml, showing that the addition of ethanol in the solution enhanced the acaricidal action of thymol. This result was supported by the LC 90 values, which were 3.3, 2.4, and 1.6 mg/ml of thymol for formulations 1, 2, and 3, respectively. This result is related to the better solubility of thymol in the hydroethanolic formulation, since the spectroscopic analysis revealed that the thymol dissolved more completely in this formulation. This fact was evident once the R (2) obtained from the linear regression analysis of the relation absorbance × concentration of the formulations 1, 2, and 3 approached the optimal value (R (2)?=?1) in the following sequence: 1, 2, and 3 (0.717, 0.901, and 0.968, respectively). PMID:22797607

Daemon, Erik; Monteiro, Caio Márcio Oliveira; Maturano, Ralph; Senra, Tatiane Oliveira Souza; Calmon, Fernanda; Faza, Aline; de Azevedo Prata, Márcia Cristina; Georgopoulos, Stéfanos Leite; de Oliveira, Luiz Fernando Cappa

2012-11-01

124

Acaricidal activity of Thymus vulgaris oil and its main components against Tyrophagus putrescentiae, a stored food mite.  

PubMed

The acaricidal activities of compounds derived from Thymus vulgaris (thyme) oil against Tyrophagus putrescentiae were assessed using an impregnated fabric disk bioassay, and were compared with those of the synthetic acaricides, benzyl benzoate and N,N-diethyl-m-toluamide. The observed responses differed according to dosage and chemical components. The 50% lethal dose (LD50) value of the T. vulgaris oil against T. putrescentiae was 10.2 microg/cm2. Biologically active constituents derived from T. vulgaris oil were purified by using silica gel chromatography and high-performance liquid chromatography. The structures of acaricidal components were analyzed by gas chromatography-mass spectrometry, 1H nuclear magnetic resonance (NMR), 13C NMR, 1H-13C COSY-NMR, and DEPT-NMR spectra, and were subsequently identified as carvacrol and thymol. Carvacrol was the most toxic compound with LD50 values (4.5 microg/cm2) significantly different from thymol (11.1 microg/cm2), benzyl benzoate (11.3 microg/cm2), and N,N-diethyl-m-toluamide (13.9 microg/cm2). Linalool was as toxic as was N,N-diethyl-m-toluamide. The lower LD50 of carvacrol indicates that it may be the major contributor of the toxicity of T. vulagaris oil against the stored food mite, although it only constitutes 14.2% of the oil. From this point of view, carvacrol and thymol can be very useful as potential control agents against stored food mite. PMID:18326186

Jeong, E Y; Lim, J H; Kim, H G; Lee, H S

2008-02-01

125

Acaricidal toxicities of 1-hydroxynaphthalene from Scutellaria barbata and its derivatives against house dust and storage mites.  

PubMed

The essential oil of Scutellaria barbata was extracted using a steam distillation and then evaluated via fumigant and contact toxicity bioassays against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Tyrophagus putrescentiae. The acaricidal toxicities of 1-hydroxynaphthalene from S. barbata oil and its derivatives were determined and compared with those of benzyl benzoate. Based on the LD50 values of 1-hydroxynaphthalene derivatives against D. farinae, D. pteronyssinus, and T. putrescentiae, obtained using a fumigant toxicity bioassay, the acaricidal activity of 1-hydroxynaphthalene (2.11, 2.37, and 4.50 µg/cm2) was 4.76, 6.00, and 2.68 times higher than that of benzyl benzoate (10.05, 9.50, and 12.50 µg/cm2) in the corresponding order, which was followed by that of 2-hydroxynaphthalene (9.50, 9.00, and 11.50 µg/cm2). On the contact toxicity bioassay, the acaricidal activity of 1-hydroxynaphthalene (0.79, 0.92, and 2.50 µg/cm2) was 9.49, 6.52, and 3.76 times higher than that of benzyl benzoate (7.50, 6.00, and 9.41 µg/cm2), which was followed by that of 2-hydroxynaphthalene (4.21, 4.80, and 6.50 µg/cm2). In conclusion, our results indicate that S. barbata oil and 1-hydroxynaphthalene derivatives might be effective natural agents for the management of house dust and storage mites. PMID:23757178

Yang, Ji-Yeon; Kim, Min-Gi; Lee, Hoi-Seon

2013-07-01

126

Acaricidal activities of major constituents of essential oil of Juniperus chinensis leaves against house dust and stored food mites.  

PubMed

The acaricidal activities of major constituents from the oil of Juniperus chinensis (var. globosa) leaves were compared with those of DEET (N,N-diethyl-m-toluamide) by using impregnated fabric disk bioassay against Dermatophagoides spp. and Tyrophagus putrescentiae. Toxicity varied with doses as well as chemical composition. The 50% lethal doses (LD50) of J. chinensis oil against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and T. putrescentiae were 21.60, 19.89, and 38.10 microg/cm2, respectively. The active constituent was purified using silica gel chromatography and high-performance liquid chromatography. The acaricidal component was identified as bomyl acetate through gas chromatography-mass spectrometry, 1H nuclear magnetic resonance (NMR), 13C-NMR, 1H-13C shift correlation spectrum-NMR, and distortionless enhancement by polarization transfer-NMR. The LD50 of bornyl acetate (2.94 microg/cm2) against D. farinae was significantly lower than those of DEET (37.13 microg/cm2) and alpha-eudesmol (29.72 microg/cm2). Similar results were observed when bomyl acetate and alpha-eudesmol were tested against D. pteronyssinus and T. putrescentiae. The lower LD50 of bornyl acetate indicates that it may be responsible for the major acaricidal activity against house dust and stored food mites, even though it constitutes only 19.5% of J. chinensis oil. Overall, these findings indicated that bornyl acetate and c-eudesmol have potential for use as control agents against house dust and stored food mites. PMID:19722401

Lee, Chi-Hoon; Park, Joon-Moh; Song, Ha-Yun; Jeong, Eun-Young; Lee, Hoi-Seon

2009-08-01

127

CYP9Q-mediated detoxification of acaricides in the honey bee (Apis mellifera).  

PubMed

Although Apis mellifera, the western honey bee, has long encountered pesticides when foraging in agricultural fields, for two decades it has encountered pesticides in-hive in the form of acaricides to control Varroa destructor, a devastating parasitic mite. The pyrethroid tau-fluvalinate and the organophosphate coumaphos have been used for Varroa control, with little knowledge of honey bee detoxification mechanisms. Cytochrome P450-mediated detoxification contributes to pyrethroid tolerance in many insects, but specific P450s responsible for pesticide detoxification in honey bees (indeed, in any hymenopteran pollinator) have not been defined. We expressed and assayed CYP3 clan midgut P450s and demonstrated that CYP9Q1, CYP9Q2, and CYP9Q3 metabolize tau-fluvalinate to a form suitable for further cleavage by the carboxylesterases that also contribute to tau-fluvalinate tolerance. These in vitro assays indicated that all of the three CYP9Q enzymes also detoxify coumaphos. Molecular models demonstrate that coumaphos and tau-fluvalinate fit into the same catalytic pocket, providing a possible explanation for the synergism observed between these two compounds. Induction of CYP9Q2 and CYP9Q3 transcripts by honey extracts suggested that diet-derived phytochemicals may be natural substrates and heterologous expression of CYP9Q3 confirmed activity against quercetin, a flavonoid ubiquitous in honey. Up-regulation by honey constituents suggests that diet may influence the ability of honey bees to detoxify pesticides. Quantitative RT-PCR assays demonstrated that tau-fluvalinate enhances CYP9Q3 transcripts, whereas the pyrethroid bifenthrin enhances CYP9Q1 and CYP9Q2 transcripts and represses CYP9Q3 transcripts. The independent regulation of these P450s can be useful for monitoring and differentiating between pesticide exposures in-hive and in agricultural fields. PMID:21775671

Mao, Wenfu; Schuler, Mary A; Berenbaum, May R

2011-08-01

128

CYP9Q-mediated detoxification of acaricides in the honey bee (Apis mellifera)  

PubMed Central

Although Apis mellifera, the western honey bee, has long encountered pesticides when foraging in agricultural fields, for two decades it has encountered pesticides in-hive in the form of acaricides to control Varroa destructor, a devastating parasitic mite. The pyrethroid tau-fluvalinate and the organophosphate coumaphos have been used for Varroa control, with little knowledge of honey bee detoxification mechanisms. Cytochrome P450-mediated detoxification contributes to pyrethroid tolerance in many insects, but specific P450s responsible for pesticide detoxification in honey bees (indeed, in any hymenopteran pollinator) have not been defined. We expressed and assayed CYP3 clan midgut P450s and demonstrated that CYP9Q1, CYP9Q2, and CYP9Q3 metabolize tau-fluvalinate to a form suitable for further cleavage by the carboxylesterases that also contribute to tau-fluvalinate tolerance. These in vitro assays indicated that all of the three CYP9Q enzymes also detoxify coumaphos. Molecular models demonstrate that coumaphos and tau-fluvalinate fit into the same catalytic pocket, providing a possible explanation for the synergism observed between these two compounds. Induction of CYP9Q2 and CYP9Q3 transcripts by honey extracts suggested that diet-derived phytochemicals may be natural substrates and heterologous expression of CYP9Q3 confirmed activity against quercetin, a flavonoid ubiquitous in honey. Up-regulation by honey constituents suggests that diet may influence the ability of honey bees to detoxify pesticides. Quantitative RT-PCR assays demonstrated that tau-fluvalinate enhances CYP9Q3 transcripts, whereas the pyrethroid bifenthrin enhances CYP9Q1 and CYP9Q2 transcripts and represses CYP9Q3 transcripts. The independent regulation of these P450s can be useful for monitoring and differentiating between pesticide exposures in-hive and in agricultural fields. PMID:21775671

Mao, Wenfu; Schuler, Mary A.; Berenbaum, May R.

2011-01-01

129

Verbenone structural analogues isolated from Artemesia aucheri as natural acaricides against Dermatophagoides spp. and Tyrophagus putrescentiae.  

PubMed

The acaricidal activities of Artemisia aucheri oil and (1S)-(-)-verbenone structural analogues were evaluated using a fumigant method against Dermatophagoides farinae , Dermatophagoides pteronyssinus , and Tyrophagus putrescentiae and then compared to those of benzyl benzoate. On the basis of the LD50 values against D. farinae , (1S)-(-)-verbenone (1.38 ?g/cm(2)) was about 7.4 times more active than benzyl benzoate (10.15 ?g/cm(2)), followed by (+)-trans-myrtanol (2.27 ?g/cm(2)), (-)-trans-myrtanol (2.30 ?g/cm(2)), and A. aucheri oil (8.75 ?g/cm(2)). (1S)-(-)-Verbenone (1.25 ?g/cm(2)) was approximately 7.8 times more effective against D. pteronyssinus than benzyl benzoate (9.80 ?g/cm(2)), followed by (+)-trans-myrtanol (2.18 ?g/cm(2)), (-)-trans-myrtanol (2.22 ?g/cm(2)), and A. aucheri oil (8.46 ?g/cm(2)). In the case of T. putrescentiae , (1S)-(-)-verbenone (3.75 ?g/cm(2)) was roughly 3.5 times more toxic than benzyl benzoate (13.25 ?g/cm(2)), followed by (+)-trans-myrtanol (12.57 ?g/cm(2)), (-)-trans-myrtanol (12.95 ?g/cm(2)), and A. aucheri oil (11.55 ?g/cm(2)). These results indicate that A. aucheri oil and (1S)-(-)-verbenone structural analogues may be effective natural agents to control house dust and storage mites. PMID:24295367

Yang, Ji-Yeon; Lee, Hoi-Seon

2013-12-18

130

Dissipation behavior of propargite--an acaricide residues in soil, apple (Malus pumila) and tea (Camellia sinensis).  

PubMed

Propargite, recently introduced in India, is an effective acaricide on a large number of crops most of which are consumed by human beings directly or after processing. Therefore, it has become important to check the dissipation behavior of propargite in edible raw commodities, processed products and in the environment. In the present study, dissipation of residue of this acaricide in soil, apple fruit and tea (green tea leaves, manufactured tea, infusion and spent leaves) was studied. Analysis was carried out using high performance-liquid chromatography with UV detection system. The dissipation rate was found to vary with the nature of studied crop/sample. In soil, half-life ranged from 43 to 45 days, while in plant matrices (tea and apple) it ranged 1.66-2.61 days. The percent transfer of propargite residue from manufactured tea to infusion was 23.60-40.00; however, 35.71-53.20% of the residues remained stuck to the spent leaves. PMID:15621197

Kumar, Vipin; Sood, Chitra; Jaggi, Shivani; Ravindranath, S D; Bhardwaj, S P; Shanker, Adarsh

2005-02-01

131

Acaricidal properties of Artemisia absinthium and Tanacetum vulgare (Asteraceae) essential oils obtained by three methods of extraction.  

PubMed

Essential oils of Artemisia absinthium L. and Tanacetum vulgare L. were extracted by three methods, a microwave assisted process (MAP), distillation in water (DW) and direct steam distillation (DSD), and tested for their relative toxicity as contact acaricides to the two spotted spider mite, Tetranychus urticae Koch. All three extracts of A. absinthium and of T. vulgare were lethal to the spider mite but to variable degrees. The LC50 obtained from the DSD oil of A. absinthium was significantly lower (0.04 mg/cm2) than that of the MAP (0.13 mg/cm2) and DW (0.13 mg/cm2) oil of this plant species. DSD and DW extracts of T. vulgare were more toxic (75.6 and 60.4% mite mortality, respectively, at 4% concentration) to the spider mite than the MAP extract (16.7% mite mortality at 4% concentration). Chromatographic analysis indicated differences in composition between the more toxic DSD oil of A. absinthium and the other two extracts of this plant, indicating that a sesquiterpene (C15H24) compound present in the DSD oil and absent in the other two may enhance the toxicity of the DSD oil. Chemical analysis of the T. vulgare extracts indicated that beta-thujone is by far the major compound of the oil (>87.6%) and probably contributes significantly to the acaricidal activity of the oil. PMID:11233109

Chiasson, H; Bélanger, A; Bostanian, N; Vincent, C; Poliquin, A

2001-02-01

132

In vitro assessment of the acaricidal activity of computer-selected analogues of carvacrol and salicylic acid on Rhipicephalus (Boophilus) microplus.  

PubMed

Rhipicephalus (Boophilus) microplus is a tick that causes huge economic losses in cattle. The indiscriminate use of acaricides has generated resistance to most compounds present on the market. This makes further investigation on other potential acaricides necessary, the in silico assay being an alternative to the design of new compounds. In the present study a biosilico assay was performed using TOMOCOMD-CARDD (TOpological MOlecular COMputer Design-Computer-Aided Rational Drug Design) and WEKA (Waikato Environment for Knowledge Analysis) software. Two carvacrol and four salicylic acid derivatives, synthesized by conventional methods and evaluated with the larval packet test on larvae of R. (B.) microplus were selected. All evaluated compounds presented acaricidal activity; however, ethyl 2-methoxybenzoate (91.8 ± 1.7 % mortality) and ethyl 2,5-dihydroxybenzoate (89.1 ± 1.6 % mortality) showed greater activity than salicylic acid. With regard to the carvacrol analogues, carvacrol acetate (67.8 ± 2.1 % mortality) and carvacrol methyl ether (71.7 ± 1.6 % mortality) also showed greater activity than carvacrol (35.9 ± 3.2 % mortality). TOMOCOMD-CARDD and WEKA software were helpful tools in the search for alternative structures with potential acaricidal activity on R. (B.) microplus. PMID:23543288

Concepción, Ramírez L; Froylán, Ibarra V; Herminia I, Pérez M; Norberto, Manjarrez A; Héctor J, Salgado Z; Yeniel, González C

2013-10-01

133

World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for evaluating the efficacy of acaricides against ticks (Ixodidae) on ruminants  

Microsoft Academic Search

These guidelines have been prepared to assist in the planning, conduct and interpretation of studies for the assessment of the efficacy of acaricides (excluding vaccines and other bio-control agents) against single and multi-host ticks (Ixodidae) on ruminants. Information is provided on the selection of animals, dose determination, dose confirmation and field studies, record keeping and result interpretation. The use of

P. A. Holdsworth; D. Kemp; P. Green; R. J. Peter; C. De Bruin; N. N. Jonsson; T. Letonja; S. Rehbein; J. Vercruysse

2006-01-01

134

Acaricidal effects of herb essential oils against Dermatophagoides farinae and D. pteronyssinus (Acari: Pyroglyphidae) and qualitative analysis of a herb Mentha pulegium (pennyroyal)  

PubMed Central

This experiment was undertaken to screen the acaricidal effects of herb essential oils (pennyroyal, ylang ylang, citronella, lemon grass, tea tree, and rosemary) at different doses (0.1, 0.05, 0.025, 0.0125, and 0.00625 µl/cm2) and exposure times (5, 10, 20, 20, 30 and 60 min) on house dust mites Dermatophgoides farinae and D. pteronyssinus. The most effective acaricidal components of pennyroyal (Mentha pulegium) were analyzed using a gas chromatography-mass spectrometer (GC-MS). Of these essential oils, the most effective was pennyroyal, which is composed essentially of pulegone (> 99%), at a dose of 0.025 µl/cm2 which at an exposure time of 5 min killed more than 98% of house dust mites. In the pennyroyal fumigation test, the closed method was more effective than the open method and maximum acaricidal effect was 100% at 0.025 µl/cm2, 60 min. The results show that herb essential oils, in particular, pennyroyal was proved to have potent acaricidal activity. PMID:16809961

Rim, In-Sook

2006-01-01

135

Acaricidal activity of ethanolic extract from aerial parts of Tagetes patula L. (Asteraceae) against larvae and engorged adult females of Rhipicephalus sanguineus (Latreille, 1806)  

PubMed Central

Background The tick Rhipicephalus sanguineus is the species with the largest worldwide distribution and is proven to be involved in the transmission of pathogens such as Babesia canis, Ehrlichia canis, Coxiella burnetii, Rickettsia ricketsii, Rickettsia conorii, among others. Studies have demonstrated acquisition of resistance to some of the active principles used in commercial formulations of acaricides. Tagetes patula (Asteraceae) is a plant with highlighted economic and commercial importance due to the production of secondary metabolites with insecticide and acaricide potential, mainly flavonoids, thiophenes and terpenes. Methods The in vitro acaricide action of the ethanolic 70% extract from aerial parts of T. patula, obtained by percolation, was evaluated against larvae and engorged adult females of Rhipicephalus sanguineus by immersion test for 5?minutes. The chemical characterization of this extract was done by liquid chromatography coupled with mass spectrometry (LC-MS), using direct injection of sample. Results Despite T. patula not proving lethal to adults in any of the concentrations tested, at 50.0?mg/mL oviposition rate decreased by 21.5% and eliminated 99.78% of the larvae. Also it was determined that the best results were obtained with 5?minutes of immersion. From the chromatographic analysis twelve O-glycosylated flavonoids were identified. Conclusions This is the first report on the acaricidal activity of T. patula extract against Rh. sanguineus. If we consider the application of the product in the environment, we could completely eliminate the larval stage of development of the ixodid Rh. sanguineus. PMID:23244493

2012-01-01

136

Assessment of fungal isolates for development of a myco-acaricide for cattle tick control.  

PubMed

Entomopathogenic fungal isolates of Arachnid origin were assessed for their ability to produce mortality and inhibit egg hatching in Boophilus microplus with the aim of selecting an isolate for development into a myco-acaricide for control of cattle ticks. The ability of the most promising isolate to target developmental stages of more than one tick species and the optimum concentration of fungal inoculum to be used for future studies were determined. Metarhizium anisopliae was the most pathogenic of the three fungal species tested on B. microplus, producing shorter average survival times (ASTs) for engorged adults (AST = 5.2 +/- 0.1 days) and larvae (AST = 9.3 +/- 0.4 days), and a longer average hatching times (AHT; AHT = 19.8 +/- 0.5 days) in comparison to Simplicillium lamellicola and Paecilomyces farinosus. In comparative studies on two tick species with similar life cycles, M. anisopliae produced a shorter AST in engorged adult B. microplus (AST = 8.8 +/- 0.3 days) than Rhipicephalus sanguineus (AST = 10.3 +/- 0.3 days). M. anisopliae was pathogenic to larvae of B. microplus (AST = 7.7 +/- 0.4 days), however, had no effect on larvae of R. sanguineus (AST = 14.6 +/- 0.3 days) as the AST of this treatment was similar to its untreated control (AST = 14.1 +/- 0.4 days). M. anisopliae lengthened the AHTs in both B. microplus (AHT = 16.4 +/- 0.3 days) and R. sanguineus (AHT = 16.7 +/- 0.3 days) in comparison to the controls. The ASTs of engorged adult B. microplus treated with M. anisopliae shortened as the concentration was increased from 1 x 10(7) to 5 x 10(8) conidia/ mL. A further increase in concentration, 1 x 10(9) conidia/mL (AST = 10.2 +/- 0.4 days) did not shorten or lengthen the AST in comparison to 5 x 10(8) conidia/mL (AST = 9.4 +/- 0.3 days). PMID:16187897

Polar, Perry; Kairo, Moses T K; Peterkin, Dorothy; Moore, Dave; Pegram, Rupert; John, Sally-Ann

2005-01-01

137

Acaricidal activity of extract of Artemisia absinthium against Rhipicephalus sanguineus of dogs.  

PubMed

The objective of the study was to evaluate the in vitro efficacy of different concentrations of chloroform extract obtained from the aerial parts of Artemisia absinthium in comparison to amitraz on adults, eggs and larvae of the dog tick Rhipicephalus sanguineus using the adult immersion test (AIT), egg hatchability test (EHT) and larval packet test (LPT), respectively. Five concentrations of the extract (1.25, 2.5, 5, 10 and 20 %) with three replications for each concentration were used in all the bioassays. A control group was established (water + dimethylsulphoxide) together with a positive control group (amitraz), with three repetitions each. In AIT, the mortality rates were 0.0, 13.3, 16.7, 33.3 and 93.3 % in concentrations of 1.25, 2.5, 5, 10 and 20 %, respectively, and the variation was significant (p=0.0151). The LC50 (CI) and LC95 (CI) values were calculated as 8.793 % (8.217-9.408) and 34.59 % (29.71-40.26), respectively. The egg production was reduced by 6.6, 6.6, 18.3, 42.5 and 85.1 % in the concentrations of 1.25, 2.5, 5, 10 and 20 %, respectively, and it was statistically significant (p=0.0274). In EHT, hatching was completely inhibited at 5, 10 and 20 % displaying 100 % ovicidal action while at the concentrations of 1.25 and 2.5 %, the inhibition rates were 20 and 60 %, respectively. In LPT, the extract caused 100 % mortality of larvae in the concentrations of 5, 10 and 20 % after 24 h while at the concentrations of 1.25 and 2.5 %, the mortality rates were 54.3 and 96.7 %, respectively. The LC50 (CI) and LC95 (CI) values were determined to be 1.11 % (1.099-1.121) and 2.37 % (2.328-2.423), respectively. The results show that the extract of A. absinthium has acaricidal properties and could be useful in controlling R. sanguineus which is an efficient vector of pathogens both in dogs and humans. PMID:24288053

Godara, R; Parveen, S; Katoch, R; Yadav, A; Verma, P K; Katoch, M; Kaur, D; Ganai, A; Raghuvanshi, P; Singh, N K

2014-02-01

138

[Resistance of Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) to acaricides that inhibit cellular respiration in citrus: cross-resistance and fitness cost].  

PubMed

Acaricides that inhibit cellular respiration play an important role in the control of Brevipalpus phoenicis (Geijskes) in citrus groves in Brazil. Studies were conducted to evaluate: (a) the variability in the susceptibility among B. phoenicis populations collected from citrus groves to cyhexatin, azocyclotin, propargite and sulphur; (b) cross-resistance relationships between propargite and azocyclotin, cyhexatin, dinocap, pyridaben and sulphur; and (c) the fitness cost associated with propargite resistance in B. phoenicis under laboratory conditions. A residual-type contact bioassay was used to characterize the susceptibility. The susceptibility was estimated with diagnostic concentrations based LC(95) of each acaricide. The cross-resistance was evaluated by characterizing the concentration-mortality responses of susceptible (S) and propargite-resistant (Propargite-R) strains. The fitness cost was evaluated by measuring the biological parameters of S and Propargite-R strains on citrus fruits at 25 +/- 1 degrees C and fotophase of 14h. Significant differences in the susceptibility of B. phoenicis were detected at diagnostic concentration of cyhexatin (survivorship from 16.3% to 80.5%), azocyclotin (from 3.0% to 15.0%), propargite (from 1.0% a 71.6%) and sulphur (from 9.0% to 82.6%). A low intensity of cross-resistance was detected between propargite and the acaricides azocyclotin (1.8-fold), cyhexatin (4.6-fold), dinocap (3.5-fold) and pyridaben (3.5-fold). On the other hand, the intensity of cross-resistance to sulphur (> 111-fold) was very high. There was no fitness cost associated with B. phoenicis resistance to propargite, based on biological parameters evaluated. Therefore, the use of these acaricides should also be done very carefully in resistance management of B. phoenicis to acaricides. PMID:17934623

Franco, Cláudio R; Casarin, Nádia F B; Domingues, Felipe A; Omoto, Celso

2007-01-01

139

In-Vitro Assessment of the Acaricidal Properties of Artemisia annua and Zataria multiflora Essential Oils to Control Cattle Ticks  

PubMed Central

Background The aim of this study was to investigate the ‘acaricidal effect’ of Zataria multiflora and Artemisia annua essential oils on Rhipicephalus (Boophilus) annulatus. Methods This study was carried out in 2009 in the Laboratory of Parasitology of the Faculty of Veterinary Medicine of Shahrekord University, west central Iran. Six dilutions (5, 10, 20, 40, 60 and 80 µL/cm3) of both essential oils were used against engorged female R. (Boophilus) annulatus ticks using an in vitro immersion method. The mortality rates for each treatment were recorded 6, 15 and 24 hours post inoculation (hpi). Mortality rate was analyzed using Repeated Measures Analysis of Variance, and comparison of means was carried out using General Linear Models Procedure. Results The mortality rate caused by different dilutions of Z. multiflora essential oil ranged from 26.6% (using 10 µL/cm3) to 100% (using 40 µL/cm3) and for A. annua essential oil it was 33.2 to 100% (using 20 and 80 µL/cm3, respectively) by the end of the experiment (36 hpi). No mortality was recorded for the non-treated control group or for dilutions less than 5 and 10 µL/cm3 using Zataria and Artemisia essential oils, respectively. For Z. multiflora mortality peaked at 15 hpi for all concentrations other than 20 µL/cm3 and took 24 h to achieve its maximum effect while for A. annua the two highest concentrations needed 24 hpi to reach their full effect. In addition, essential oils applied at more than 20 and 60 µL/cm3 caused 100% egg-laying failure in engorged female ticks by Zataria and Artemisia, respectively while no failure was observed for the non-treated control group. The mortality rate in both botanical acaricides was dose-dependent. Conclusion Both these medicinal plants have high potential acaricidal effects on the engorged stage of R. (Boophilus) annulatus in vitro. PMID:22347275

Pirali-Kheirabadi, KH; Teixeira da Silva, JA

2011-01-01

140

Seasonal and spatial distribution of ixodid tick species feeding on naturally infested dogs from Eastern Austria and the influence of acaricides/repellents on these parameters  

PubMed Central

Background Effective control of tick infestation and pathogen transmission requires profound knowledge of tick biology in view of their vector function. The particular time of the year when the different tick species start to quest and the favoured sites on the canine host are of major interest. The efficacy of acaricides/repellents to control ticks in the field requires observation. Methods To address these issues, 90 dogs, grouped in “untreated”, “acaricide/repellent” (permethrin) and “acaricide only” (fipronil) animals and subjected to tick infestation under natural conditions in Burgenland (Eastern Austria), were examined. The number and species of ticks occurring during and outside the protection time was evaluated during a period of 11?months and the biting location on the dogs’ skin was recorded. Results Of the 700 ticks collected, the most common species in that particular walking area was Ixodes ricinus, followed by Dermacentor reticulatus and Haemaphysalis concinna. Regarding the on-host activity, D. reticulatus displayed more infestations in early spring and late autumn, whereas I. ricinus occurred almost one month later in spring and one month earlier in autumn. H. concinna followed a monophasic pattern of activity with a peak in summer. The preferred feeding sites of the ticks on the dogs were on the head, neck, shoulder and chest. This distribution over the dog’s body was not influenced by the use of the drugs, although on the whole fewer ticks (22.5% of all ticks) were found during the protection time. Interestingly, differences occurred with the use of drugs compared to non-protected dogs with regard to the infestation over the year. Acaricide-treated dogs displayed a higher prevalence in April, May and September, whereas dogs of the acaricide/repellent group showed a higher infestation in March, July, October and November. Conclusion The different tick species display different on-dog activity peaks over the year, during which particular canine diseases can be expected and predicted, considering the specific incubation times for each pathogen. The tick species occurring in this study do not seem to choose particular sites on the dogs. Their arrival place seems to represent the attachment and consequently the feeding sites. The use of acaricides leads to a significantly (p<0.01) lower number of infesting ticks but no change of the distribution pattern on the dogs was observed. PMID:23510263

2013-01-01

141

Lice, Scabies and Pregnancy  

MedlinePLUS

... Supplement 2): S146-S151. Dzierzawski A. 1977. Embryo-toxicity studies of lindane in the golden hamster, rat ... 435-444. Miyamoto J. 1976 Degradation, metabolism and toxicity of synthetic pyrethroids. Environ Health Criter 14:15- ...

142

Scabies: Signs and Symptoms  

MedlinePLUS

... Resource Center Residents & Fellows Resource Center Publications Media Relations Toolkit Leadership Institute Volunteer and mentor opportunities Member directory AAD store International resources My account Patient education resources Awards, grants, ...

143

Scabies: Tips for Managing  

MedlinePLUS

... Resource Center Residents & Fellows Resource Center Publications Media Relations Toolkit Leadership Institute Volunteer and mentor opportunities Member directory AAD store International resources My account Patient education resources Awards, grants, ...

144

Evaluation of the acaricide effect of thymol, menthol, salicylic acid, and methyl salicylate on Boophilus microplus (Canestrini 1887) (Acari: Ixodidae) larvae  

Microsoft Academic Search

The tick Boophilus microplus is the principal species of ectoparasite that impairs dairy cattle productivity in Brazil. Its control is mainly by using\\u000a synthetic chemical products during its parasitic phase. The purpose of this study is to evaluate the acaricide activity of\\u000a four products of natural origin. Depending on solubility, tests were conducted with solutions in distilled water or emulsified

Adriana Maria da Silveira Novelino; Erik Daemon; Geraldo Luiz Gonçalves Soares

2007-01-01

145

Acaricidal activity of the essential oils from Eucalyptus citriodora and Cymbopogon nardus on larvae of Amblyomma cajennense (Acari: Ixodidae) and Anocentor nitens (Acari: Ixodidae)  

Microsoft Academic Search

The present study evaluated the acaricidal activity of essential oils from Eucalyptus citriodora and Cymbopogon nardus on non-engorged larvae of Amblyomma cajennense and Anocentor nitens. In order to carry out the study, six groups were formed, each concentration being a treatment (6.25%, 12.5%, 25%, and 50%,\\u000a respectively) and also with the creation of a control group (distilled water) and a

Mateus Aparecido Clemente; Caio Márcio de Oliveira Monteiro; Márcio Goldner Scoralik; Fernando Teixeira Gomes; Márcia Cristina de Azevedo Prata; Erik Daemon

2010-01-01

146

Acaricidal activity of petroleum ether extract of neem (Azadirachta indica) oil and its four fractions separated by column chromatography against Sarcoptes scabiei var. cuniculi larvae in vitro.  

PubMed

The petroleum ether extract of neem oil and its four fractions separated by column chromatography was diluted at different concentrations with liquid paraffin. The acaricidal bioassay was conducted using a dipping method. The results indicated that the median lethal concentration (LC50) of the petroleum ether extract (at the concentration of 500.0ml/l) was 70.9ml/l, 24h after treatment. At concentrations of 500.0, 250.0, 125.0, 62.5 and 31.2ml/l, the median lethal times (LT50) of the petroleum ether extract were 8.7, 8.8, 10.8, 11.5 and 13.1h, respectively. Thin-layer chromatography (TLC) showed that the petroleum ether extract of neem oil separated into four fractions (F1-F4). Acaricidal activity of 68.3% and 100.0% in the F2 and F4 was confirmed. These results suggest that petroleum ether extracts of neem oil and its four fractions possess useful acaricidal activity in vitro. PMID:22349080

Deng, Yunxia; Shi, Dongxia; Yin, Zhongqiong; Guo, Jianhong; Jia, Renyong; Xu, Jiao; Song, Xu; Lv, Cheng; Fan, Qiaojia; Liang, Xiaoxia; Shi, Fei; Ye, Gang; Zhang, Wei

2012-04-01

147

The acaricidal efficacy of aqueous neem extract and ivermectin against Sarcoptes scabiei var. cuniculi in experimentally infested rabbits.  

PubMed

Sarcoptes scabiei var. cuniculi is one of the most important veterinary ectoparasites in rabbits and results in considerable loss of weight, productivity, and wool quality. The acaricidal activity of aqueous leaf extract of neem (CAN) and ivermectin (IVR) were evaluated in vitro and in vivo against S. scabiei var. cuniculi. Rabbits were classified into four groups (ten rabbits each). The first group (group 1) was designated as the negative control group. Each rabbit of the other groups was experimentally infested with 50 mites. One month post-infestation, the second group (group 2) was not treated and taken into account as the positive control group. The third group (group 3) was subcutaneously injected with 1 % IVR (200 ?g/kg body weight, three times within a week interval). The fourth group (group 4) was treated topically with CAN (25 %) every 3 days for three consecutive weeks. Index scoring of lesions was described weekly. The number of live mites (larvae, nymphs, and adults) on each rabbit was counted on the 14th, 28th, and 42th day post-treatment (PT). Blood samples were taken 28 and 42 days PT for estimation of some chemical parameters. The body weight and cumulative body weight gain were recoded 14, 28, and 42 days PT. CAN (40 %) was highly efficacious against larvae of S. scabiei var. cuniculi as 100 % mortality was reached 24 h PT. On the other hand, all treated mites with CAN (20 %) and IVR died 48 h PT. The lethal values of CAN (LC50, LC90, LC95, and LC99) were 7.496, 14.67, 17.75, and 25.37 %, respectively, 48 h PT. Lesion scoring in groups 3 and 4 were significantly decreased (P???0.05), reaching 0.20 and 0.40, respectively, when compared with that of group 2 (4.00), 42 days PT. Twenty-eight days PT, the reduction percentages of mites infesting rabbits were 93.38 and 93.09 % for IVR and CAN, respectively. However, complete mite reduction was reached 42 days PT. Rabbits treated with CAN did not show signs of restlessness or irritation, respiratory signs, or inflammation on the eye and/or skin at the time of application or afterwards. Regarding biochemical analysis, the levels of aspartate aminotransferase, alanine aminotransferase, creatinine, and total cholesterol in rabbits treated with CAN were decreased significantly (P???0.05) than those of rabbits of the positive control group and those treated with IVR. On the other hand, the levels of total protein, albumin, and globulin of rabbits in group 4 were significantly (P???0.05) increased when compared with the corresponding values of groups 2 and 3. The body weight and cumulative body weight gain of rabbits treated with CAN were significantly increased (P???0.05) when compared with such values of groups 2 and 3, 28 and 42 days PT. The present data indicated that CAN had in vitro and in vivo acaricidal efficiency similar to that of IVR and improved the performance of rabbits without inducing adverse effects on treated rabbits; consequently, CAN could be suitable as a promising alternative acaricide for veterinary use. PMID:23572045

Seddiek, Shaker A; Khater, Hanem F; El-Shorbagy, Mohamed M; Ali, Ali M

2013-06-01

148

Acaricidal effects of cardiac glycosides, azadirachtin and neem oil against the camel tick, Hyalomma dromedarii (Acari: Ixodidae).  

PubMed

The cardiac glycoside, digitoxin, from Digitalis purpurea L (Scrophulariaceae), a cardiac glycosidal (cardenolide) extract from Calotropis procera (Ait) R Br (Asclepiadaceae), azadirachtin and neem oil from Azadirachta indica A Juss (Meliaceae) were tested for their effects against larvae and adult stages of the camel tick, Hyalomma dromedarii Koch (Acari: Ixodidae). The contact LC50 values of the first three materials against adults were 4.08, 9.63 and >40.7 microg cm(-2), respectively, whereas the dipping LC50 values of the four materials were 409.9, 1096, >5000 and >5000 mg litre(-1), respectively. Contact and dipping LC50 values of the extract and azadirachtin against larvae were 6.16, >20.3 microg cm(-2) and 587.7 and >2500 mg litre(-1), respectively. Azadirachtin had no effects on egg production or feeding of adults up to 5000 mg litre(-1); however at 2500 mg litre(-1), it caused significant reduction in feeding activity of larve, prolonged the period for moulting to nymphal stage, and caused 60% reduction in moultability. Results of the two cardiac glycoside materials are comparable with those of several commercial acaricides. The risks and benefits associated with the use of cardiac glycosides are considered. PMID:14620053

Al-Rajhy, DiefAlla H; Alahmed, Azzam M; Hussein, Hamdy I; Kheir, Salah M

2003-11-01

149

Acaricidal activity of Lippia gracilis essential oil and its major constituents on the tick Rhipicephalus (Boophilus) microplus.  

PubMed

The present study aimed to evaluate the activity of Lippia gracilis Schauer essential oil obtained from different L. gracilis genotypes and their major components, carvacrol and thymol against Rhipicephalus (Boophilus) microplus (cattle tick) larvae and engorged females. The larval test was performed parallel to the adult immersion test for engorged females for four L. gracilis genotypes. Similar tests were further performed for their major compounds carvacrol and thymol. Carvacrol (LC50 of 0.22 and 4.46 mg/mL, to larvae and engorged females, respectively) was more efficient than thymol (LC50 of 3.86 and 5.50 mg/mL, to larvae and engorged females, respectively). The lethal concentrations obtained for the isolated essential oil from genotypes LGRA-201 against larvae (1.31 mg/mL) and LGRA-106 against engorged females (4.66 mg/mL) confirmed the acaricidal activity of L. gracilis essential oil and its effectiveness in controlling the southern cattle tick. PMID:23337330

Cruz, Elizangela Mércia de Oliveira; Costa, Livio Martins; Pinto, Jessika Andreza Oliveira; Santos, Darlisson de Alexandria; de Araujo, Sandra Alves; Arrigoni-Blank, Maria de Fátima; Bacci, Leandro; Alves, Péricles Barreto; Cavalcanti, Sócrates Cabral de Holanda; Blank, Arie Fitzgerald

2013-07-01

150

Acaricidal activity and sublethal effects of an oxymatrine-based biopesticide on two-spotted spider mite (Acari: Tetranychidae).  

PubMed

Lethal and sublethal effects of the biopesticide Kingbo (oxymatrine 0.2 % + psoralen 0.4 %) on the two-spotted spider mite (Tetranychus urticae Koch) were investigated in laboratory bioassays. The biopesticide was applied to bean leaf discs or primary leaves by using a Potter spray tower. Acute toxicity tests showed no significant ovicidal action: toxic effect (LC50 = 55.49 ?l/l) was the result of a residual activity against larvae that hatched from the treated eggs. Preovipositional females and female teleiochrysales showed similar susceptibility (LC50 = 52.68 and 59.03 ?l/l, respectively), whereas larvae, protonymphs and female deutonymphs were the most susceptible stages (LC50 = 6.88, 13.03, and 8.80 ?l/l, respectively). In a choice test, females preferred the untreated halves of leaves over the halves treated with 2,000, 1,000, and 500 ?l/l in the first 24 h, and their oviposition in those treatments was significantly greater on the untreated halves after 24 and 48 h, as well as the summed oviposition over 72 h. Viability and reproduction of survivors, as well as population growth, were strongly affected after the treatments of preovipositional females and female teleiochrysales with 100, 50 and 25 ?l/l. On the other hand, sublethal effects on the females that survived treatment at the egg stage or reached adulthood from the eggs laid on the treated surface (treatments with 50 and 25 ?l/l) were significantly weaker. Acaricidal and sublethal effects of the biopesticide Kingbo were discussed as a starting point for further research aimed to improve management of T. urticae populations. Regulatory issues and safety concerns regarding further commercialization of this biopesticide are addressed as well. PMID:24948329

Mar?i?, Dejan; Me?o, Irena

2014-11-01

151

Assessment of the acaricidal activity of carvacrol, (E)-cinnamaldehyde, trans-anethole, and linalool on larvae of Rhipicephalus microplus and Dermacentor nitens (Acari: Ixodidae).  

PubMed

The acaricidal activity of carvacrol, (E)-cinnamaldehyde, trans-anethole, and linalool was studied on Rhipicephalus microplus and Dermacentor nitens larvae. All the substances were tested at concentrations of 2.5, 5.0, 10.0, 15.0, and 20.0 ?l/ml, with 10 repetitions per treatment. The modified larval packet technique was employed in the tests and the mortality was evaluated after 24 h. In the groups treated with carvacrol, the lowest concentration (2.5 ?l/ml) was sufficient to cause 100% death of the R. microplus and D. nitens larvae. The same concentration of (E)-cinnamaldehyde resulted in death of approximately 99% of the larvae of both tick species and reached 100% at the other concentrations. For trans-anethole, mortality rates above 90% of the R. microplus and D. nitens larvae were only observed starting at the concentration of 15.0 ?l/ml and reached 100% at the highest concentration (20.0 ?l/ml). Finally, the mortality rates of the groups treated with linalool were low, only reaching 8.4 and 14.5% at the highest concentration (20.0 ?l/ml) for larvae of D. nitens and R. microplus, respectively. These results show that carvacrol, (E)-cinnamaldehyde, and trans-anethole have acaricidal activity, particularly carvacrol and (E)-cinnamaldehyde, both of which resulted in high mortality rates for the larvae of these two tick species even at the lowest concentration. PMID:23354938

de Oliveira Souza Senra, Tatiane; Zeringóta, Viviane; de Oliveira Monteiro, Caio Márcio; Calmon, Fernanda; Maturano, Ralph; Gomes, Geovany Amorim; Faza, Aline; de Carvalho, Mario Geraldo; Daemon, Erik

2013-04-01

152

Molecular analysis of resistance to acaricidal spirocyclic tetronic acids in Tetranychus urticae: CYP392E10 metabolizes spirodiclofen, but not its corresponding enol.  

PubMed

Spirodiclofen is one of the most recently developed acaricides and belongs to the new family of spirocyclic tetronic acids (ketoenols). This new acaricidal family is an important chemical tool in resistance management strategies providing sustainable control of spider mites such as Tetranychus urticae. Spirodiclofen targets lipid biosynthesis mediated by direct inhibition of acetyl coenzyme A carboxylase (ACCase). In this study, we investigated two genetically distant spider mite strains with high resistance to spirodiclofen. Despite the strong resistance levels to spirodiclofen (up to 680-fold), only limited cross-resistance with other members of this group such as spiromesifen and spirotetramat could be detected. Amplification and sequencing of the ACCase gene from resistant and susceptible strains did not reveal common non-synonymous mutations, and expression levels of ACCase were similar in both resistant and susceptible strains, indicating the absence of target-site resistance. Furthermore, we collected genome-wide expression data of susceptible and resistant T. urticae strains using microarray technology. Analysis of differentially expressed genes revealed a broad response, but within the overlap of two resistant strains, several cytochrome P450s were prominent. Quantitative PCR confirmed the constitutive over-expression of CYP392E7 and CYP392E10 in resistant strains, and CYP392E10 expression was highly induced by spirodiclofen. Furthermore, stage specific expression profiling revealed that expression levels were not significantly different between developing stages, but very low in eggs, matching the age-dependent resistance pattern previously observed. Functional expression of CYP392E7 and CYP392E10 confirmed that CYP392E10 (but not CYP392E7) metabolizes spirodiclofen by hydroxylation as identified by LC-MS/MS, and revealed cooperative substrate binding and a Km of 43 ?M spirodiclofen. CYP392E10 also metabolizes spiromesifen, but not spirotetramat. Surprisingly, no metabolism of the hydrolyzed spirodiclofen-enol metabolite could be detected. These findings are discussed in the light of a likely resistance mechanism. PMID:23523619

Demaeght, Peter; Dermauw, Wannes; Tsakireli, Dimitra; Khajehali, Jahangir; Nauen, Ralf; Tirry, Luc; Vontas, John; Lümmen, Peter; Van Leeuwen, Thomas

2013-06-01

153

Scabies: Who Gets and Causes  

MedlinePLUS

... Resource Center Residents & Fellows Resource Center Publications Media Relations Toolkit Leadership Institute Volunteer and mentor opportunities Member directory AAD store International resources My account Patient education resources Awards, grants, ...

154

Scabies: Diagnosis, Treatment, and Outcome  

MedlinePLUS

... Resource Center Residents & Fellows Resource Center Publications Media Relations Toolkit Leadership Institute Volunteer and mentor opportunities Member directory AAD store International resources My account Patient education resources Awards, grants, ...

155

EXPOSE-R on Mission on the ISS  

NASA Astrophysics Data System (ADS)

Currently EXPOSE-R is on mission! This astrobiological exposure facility was accommodated at the universal workplace URM-D Zenith payload site, located outside the Russian Svezda Module of the International Space Station (ISS) by extravehicular activity (EVA) on March 10th 2009. It contains 3 trays accommodating 12 sample compartments with sample carriers in three levels either open to space vacuum or kept in a defined gas environment. In its 8 experiments of biological and chemical content, more than 1200 individual samples are exposed to solar ultraviolet (UV) radiations, vacuum, cosmic rays or extreme temperature variations. In their different experiments the involved scientists are studying the question of life's origin on Earth and the results of their experiments are contributing to different aspects of the evolution and distribution of life in the Universe. Additionally integrated into the EXPOSE-R facility are several dosimeters monitoring the ionising and the solar UV-radiation during the mission to deliver useful information to complement the sample analysis. In close cooperation with the DLR and the Technical University Munich (TUM), the Rheinisch -Westfülische Technischen Hochschule Aachen (RWTH Aachen) operates the experiment "Spores". a This is one of the 6 astrobiological experiments of the ROSE-Consortium" (Response of Or-ganisms to Space Environment) of the EXPOSE-R mission. In these experiments spores of bacteria, fungi and ferns are being over layered or mixed with meteorite material. The analysis of the effect of the space parameters on different biological endpoints of the spores of the mi-croorganism Bacillus subtilis will be performed after the retrieval of the experiment scheduled for the end of 2010. Parallel to the space mission an identical set of samples was accommodated into EXPOSE-R trays identical in construction to perform the Mission Ground Reference (MGR) Test. Currently this MGR Test is carried out in the Planetary and Space Simulation Facilities (PSI) of DLR, Cologne: the space parameters (vacuum, temperature and extra-terrestrial UV-radiation) as delivered from the ISS are simulated. An overview over the EXPOSE mission from the EXPOSE-R Experiment Verification Test (EVT) Program to the flight sample preparation is presented.

Panitz, Corinna; Rabbow, Elke; Rettberg, Petra; Barczyk, Simon; Kloss, Maria; Reitz, Guenther

156

Acaricidal activities of whole cell suspension, cell-free supernatant, and crude cell extract of Xenorhabdus stokiae against mushroom mite (Luciaphorus sp.)*  

PubMed Central

Xenorhabdus bacterium has been used as a biological control agent against Luciaphorus sp., a mushroom mite endemic in Thailand. To develop an effective formulation of Xenorhabdus stokiae, treatments using different parts of X. stokiae isolate PB09 culture, including whole cell suspension, cell-free supernatant, and crude cell extract, were performed. The results show that different parts of X. stokiae isolate PB09 culture could induce variable effects on mite mortality and fecundity. Application with cell-free supernatant of X. stokiae culture resulted in both the highest mite mortality rate [(89.00±3.60)%] and the lowest mite fecundity [(41.33±23.69) eggs/gravid female]. Whole cell suspension of X. stokiae isolate PB09 culture was found to be slightly less effective than its cell-free supernatant, suggesting that X. stokiae was more likely to release its metabolites with acaricidal activities to the surrounding culture media. Crude cell extract of X. stokiae was not effective against mites. Cell-free supernatant of X. stokiae isolate PB09 was the most effective biological control agent and it could be conveniently used in future formulations instead of live bacteria. PMID:22467367

Bussaman, Prapassorn; Sa-Uth, Chirayu; Rattanasena, Paweena; Chandrapatya, Angsumarn

2012-01-01

157

Chemical composition and acaricidal properties of Deverra scoparia essential oil (Araliales: Apiaceae) and blends of its major constituents against Tetranychus urticae (Acari: Tetranychidae).  

PubMed

The essential oil of Deverra scoparia Coss. & Durieu was investigated for its acaricidal activity against the worldwide pest twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). The essential oil was analyzed by fast gas chromatography (GC) and GC-mass spectrometry. The activities of its individual and blended constituents were determined. Our study showed that female mortality increased with increasing D. scoparia oil concentrations, with LD50 and LD90 values at 1.79 and 3.2 mg liter(-1), respectively. A reduction in fecundity had already been observed for concentrations of 0.064, 0.08, and 0.26 mg liter(-1) D. scoparia essential oil. Ten major components, comprising 98.52% of the total weight, were identified; a-pinene was the most abundant constituent (31.95%) followed by sabinene (17.24%) and delta3-carene (16.85%). The 10 major constituents of D. scoparia oil were individually tested against T. urticae females. The most potent toxicity was found with alpha-pinene, delta3-carene, and terpinen-4-ol. The presence of all constituents together in the artificial mixture caused a significant decrease in the number of eggs laid by females, at 0.26 mg liter(-1) (11 eggs), compared with the control (50 eggs). The toxicity of blends of selected constituents indicated that the presence of all constituents was necessary to reproduce the toxicity level of the natural oil. PMID:21882686

Attia, S; Grissa, K L; Lognay, G; Heuskin, S; Mailleux, A C; Hance, T

2011-08-01

158

Preventing Alcohol-exposed Pregnancies  

Microsoft Academic Search

Fetal alcohol exposure affects approximately 1% to 3% of live births in the United States. Family physi- cians are in a unique position to reduce the incidence of alcohol-exposed pregnancy. Fetal alcohol ex- posure can be minimized through 2 general approaches: reducing alcohol consumption or increasing effective contraception among childbearing-aged women who engage in \\

Mark B. Mengel; H. Russell Searight; Keely Cook

159

The ORGANIC Experiment on the ISS EXPOSE-R  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) and aromatic networks are among the most abundant organic material in space. PAHs and fullerenes have been identified in meteorites and are proposed as carriers for numerous astronomical absorption and emission features. Recently the fullerenes C60 and C70 have been discovered in a young planetary nebula, Tc 1 and in other astronomical environments. Thin films of selected PAHs and fullerenes have been subjected to the low Earth orbit environment as part of the ORGANIC experiment on the multi-user facility EXPOSE-R, which was deployed onboard the International Space Station (ISS) in March 2009 and retrieved by extra-vehicular activity (EVA) in January 2011. The ORGANIC experiment monitors the chemical evolution, survival, destruction, and chemical modification of PAHs and fullerenes exposed to solar illumination and cosmic radiation. The radiation dose that is collected on the ISS by the samples cannot be accurately simulated in Earth laboratories. Dark samples are shielded from the UV photons and will enable us to differentiate between the effects of exposure to photons and cosmic rays. The samples are monitored before and after space exposure; ground control samples were continuously monitored. We describe the ORGANIC experiment on the Space Station and report on laboratory ground-control measurements in the UV-Vis-NIR at NASA-Ames. Extended space exposure allows us to collect data on multiple samples which can be extrapolated to other astrophysical environments and thus greatly enhance our knowledge on the evolution of organic compounds in space environment.

Bryson, K.; Peeters, Z.; Salama, F.; Foing, B.; Ehrenfreund, P.; Jessberger, E.; Bischoff, A.; Breitfellner, M.; Schmidt, W.

2011-05-01

160

Acaricidal, pediculocidal and larvicidal activity of synthesized ZnO nanoparticles using wet chemical route against blood feeding parasites.  

PubMed

The present study was based on assessments of the anti-parasitic activities to determine the efficacies of synthesized zinc oxide nanoparticles (ZnO NPs) prepared by wet chemical method using zinc nitrate and sodium hydroxide as precursors and soluble starch as stabilizing agent against the larvae of cattle tick Rhipicephalus (Boophilus) microplus, Canestrini (Acari: Ixodidae); head louse Pediculus humanus capitis, De Geer (Phthiraptera: Pediculidae); larvae of malaria vector, Anopheles subpictus, Grassi; and filariasis vector, Culex quinquefasciatus, Say (Diptera: Culicidae). R. microplus larvae were exposed to filter paper envelopes impregnated with different ZnO NP concentrations. Direct contact method was conducted to determine the potential of pediculocidal activity. Parasite larvae were exposed to varying concentrations of synthesized ZnO NPs for 24 h. The results suggested that the mortality effects of synthesized ZnO NPs were 43% at 1 h, 64% at 3 h, 78% at 6 h, and 100% after 12 h against R. microplus activity. In pediculocidal activity, the results showed that the optimal times for measuring mortality effects of synthesized ZnO NPs were 38% at 10 min, 71% at 30 min, 83% at 1 h, and 100% after 6 h against P. humanus capitis. One hundred percent lice mortality was observed at 10 mg/L treated for 6 h. The mortality was confirmed after 24 h of observation period. The larval mortality effects of synthesized ZnO NPs were 37%, 72%, 100% and 43%, 78% and 100% at 6, 12, and 24 h against A. subpictus and C. quinquefasciatus, respectively. It is apparent that the small size and corresponding large specific surface area of small nanometer-scale ZnO particles impose several effects that govern its parasitic action, which are size dependent. ZnO NPs were synthesized by wet chemical process, and it was characterized with the UV showing peak at 361 nm. X-ray diffraction (XRD) spectra clearly shows that the diffraction peaks in the pattern indexed as the zinc oxide with lattice constants a = 3.249 and c = 5.206 Å. The FTIR spectrum showed the range of 400-4,000 cm(-1). The band at 899.56 cm(-1); 1,151.87 cm(-1); 1,396 cm(-1); and these bands showed the complete composition of ZnO NPs. SEM micrograph showed 60-120-nm size and aggregates of spherical shape nanoparticles. EDX showed the complete chemical composition of the synthesized nanoparticles of zinc oxide. The maximum efficacy was observed in zinc oxide against the R. microplus, P. humanus capitis, and the larvae of A. subpictus, C. quinquefasciatus with LC(50) values of 29.14, 11.80, 11.14, and 12.39 mg/L; r (2)?=?0.805, 0.876, 0.894, and 0.904, respectively. The synthesized ZnO NPs showed the LC(50) and r (2) values against the R. microplus (13.41 mg/L; 0.982), P. humanus capitis (11.80 mg/L; 0.966), and the larvae of A. subpictus (3.19; 0.945 mg/L), against C. quinquefasciatus (4.87 mg/L; 0.970), respectively. The control (distilled water) showed nil mortality in the concurrent assay. This is the first report on anti-parasitic activity of the synthesized ZnO NPs. PMID:21340566

Kirthi, Arivarasan Vishnu; Rahuman, Abdul Abdul; Rajakumar, Govindasamy; Marimuthu, Sampath; Santhoshkumar, Thirunavukkarasu; Jayaseelan, Chidambaram; Velayutham, Kanayairam

2011-08-01

161

First Results from EXPOSE-LIFE Experiment  

NASA Astrophysics Data System (ADS)

During the EXPOSE-LIFE-Experiment lichens, antarctic microfungi and rocks colonized by microorganisms have been exposed for 18 months on the ISS. The first results indicated survival and maintenance of metabolic activity.

de Vera, J.-P.; Onofri, S.; de La Torre, R.; Zucconi, L.; Selbmann, L.; Ott, S.; Demets, R.; Rabbow, E.; Horneck, G.

2010-04-01

162

Silent Victims: Children Exposed to Family Violence  

ERIC Educational Resources Information Center

Annually an estimated 3 million or more children are exposed to acts of domestic violence between adults in their homes. These children are at risk for abuse themselves as well as other immediate and long-term problems, especially if they have been exposed to repeated episodes of domestic violence. Multiple behavioral manifestations, including…

Kolar, Kathryn R.; Davey, Debrynda

2007-01-01

163

SUIVI MEDICAL DE SALARIES EXPOSES AU BERYLLIUM : Medical follow-up of beryllium -exposed workers  

E-print Network

1 SUIVI MEDICAL DE SALARIES EXPOSES AU BERYLLIUM : Medical follow-up of beryllium - exposed workers-up of beryllium-exposed workers. Method: a medical follow-up of workers from a factory machining beryllium (Be preventive measures. Key words: beryllium, sensitisation, occupational exposure, prevention, Lymphocyte

Boyer, Edmond

164

TREATMENT OF LEAD EXPOSED CHILDREN TRIAL  

EPA Science Inventory

The Treatment of Lead-exposed Children (TLC) clinical trial compared the effect of lead chelation with succimer to placebo therapy. Outcomes included IQ, neuropsychological function, behavior, physical growth and blood pressure three years after initiation of treatment. Residenti...

165

ERYTHROCYTE SURVIVAL IN SHEEP EXPOSED TO OZONE  

EPA Science Inventory

Ozone has been reported to produce a variety of extrapulmonary effects including changes in the specific activity of some erythrocyte enzymes. Buckley et al. (1975) reported statistically significant extrapulmonary changes in a number of human volunteers experimentally exposed to...

166

The Expose-R2 mission: astrobiology and astrochemistry in low Earth orbit  

NASA Astrophysics Data System (ADS)

EXPOSE is an exposure platform developed by ESA which permits scientists to install test samples for 1 to 2 years at the outer surface of the ISS. In that way, the impact of the open space environment on biological and biochemical sample materials can be explored. This environment, featuring full-spectrum solar light, near-vacuum, cosmic radiation, wide temperature variations and near-weightlessness, is impossible to reproduce in its entirety in the lab. As such, EXPOSE offers astrochemists and astrobiologists a chance to acquire novel scientific data. Astrochemists are interested in Low Earth Orbit conditions due to the fact that photochemistry in space is quite different from photochemistry on Earth, where the high-energy UV compounds of the solar spectrum are filtered away by our atmosphere. As for the astro biologists, EXPOSE offers an attractive opportunity to expand earlier results obtained during short-duration LEO flights, which have shown that particular microbes and, amazingly, even some multi-cellular macroscopic organisms were able to cope with a two-week exposure to space. The open space environment, often described as harsh and hostile, can apparently be tolerated by some robust inhabitants of our Earth - unprotected, in the absence of a space suit! The first mission of EXPOSE, as an external payload on the European Columbus module, happened during 2008-2009 with the test samples provided by five separate research teams. Three additional teams were involved in the monitoring of space environment. The results were published collectively in 2012 in a special issue of the monthly journal Astrobiology. Several organisms survived, having spent 1.5 years in space. The second mission was called EXPOSE-R, the R referring to ‘Russian segment’, the location where the EXPOSE instrument was installed this time. The EXPOSE-R mission took place in 2009-2011, ten science teams were involved. The publication of the results, again as a collection, is currently in preparation. A follow-on mission, EXPOSE-R2, is planned for 2014-2016. The upload of the new sample trays to the ISS will have occurred just before COSPAR 2014. In this presentation the new EXPOSE-R2 experiments are introduced, with an overview of the test samples and the scientific goals. The main characteristics of the EXPOSE platform are addressed including the sensors used to monitor the space environment. The envisaged operational flow in flight and on ground are explained. Moreover, a brief overview of the key lessons learnt from the past EXPOSE missions is provided.

Demets, René

167

Comparing the earthquake exposed and non-exposed Turkish children's Post Traumatic Stress Reactions  

Microsoft Academic Search

Unfortunately, Turkey is stretched out on the earthquake fault line; therefore, Turkish children are at risk of developing posttraumatic stress disorder (PTSD) caused by earthquake exposures and the threats of the anticipated earthquakes as well as aftershocks. This current study aimed at identifying PTSD reactions of disaster exposed and non-exposed Turkish children after the big 1999 Marmara earthquakes in the

Sefa Bulut

2006-01-01

168

CYTOGENETIC ANALYSES OF MICE EXPOSED TO DICHLOROMETHANE  

EPA Science Inventory

Chromosome damage was studied in female B6C3F1 mice exposed to dichloromethane (DCM) by subcutaneous or inhalation treatments. o increase in either the frequencies of sister chromatid exchanges (SCEs) or chromosome aberrations (CAs) in bone marrow cells was observed after a singl...

169

Politically exposed persons (PEPs): risks and mitigation  

Microsoft Academic Search

Purpose – The purpose of this paper is to consider the risks posed by politically exposed persons (PEPs) and explain the money laundering risk when entering into financial transactions and business relationships with PEPs. Risk mitigation by regulated entities and corruption prevention strategies are also outlined. To minimise money-laundering risks associated with PEPs, legislation will need to adapt to deal

Kim-Kwang Raymond Choo

2008-01-01

170

Interviews with Children Exposed to Violence  

ERIC Educational Resources Information Center

The aim of this article is to show how research practices may simultaneously follow principles of children's citizenship rights to participation and principles of protection and support when children exposed to violence are informants. The article focuses upon organisation of interview processes and interactions between adult researchers and child…

Eriksson, Maria; Nasman, Elisabet

2012-01-01

171

Exposing New Academics through Action Research?  

ERIC Educational Resources Information Center

While collaborative action research is an empowering approach to developing academic practice, it also presents a number of challenges regarding the purpose, nature and consequences of academic development. This research note raises questions and issues concerning how action research exposes new academics to the conflicts and tensions of the…

Smith, Karen; Fernie, Scott

2010-01-01

172

Mortality of workers exposed to acrylonitrile.  

PubMed

A retrospective cohort study was carried out in The Netherlands to investigate the potential carcinogenic effects in humans of occupational exposure to acrylonitrile (AN). The total study group consisted of 6803 workers "from eight chemical plants and one control plant" of whom 2842 had been exposed to AN between January 1, 1956 and July 1, 1979 for at least 6 months. All workers were employed by one of eight chemical companies. An extensive review of the available industrial hygiene data was conducted to assess the magnitude of past exposure to AN, occurrence of peak exposures, exposure to recognized potential human carcinogens, and respirator use. The total cohort was observed for mortality until January 1, 1988. In collaboration with the Central Bureau of Statistics, the causes of death were traced for the workers who died before 01-01-1988. In the exposed as well as in the nonexposed cohorts the total mortality was lower than expected, based on national mortality statistics. The observed cancer mortality in the exposed cohort was similar to the expected mortality. Specific analyses were carried out to investigate dose-response relationships and latency for total mortality and lung cancer mortality. Overall, no indications were found for a carcinogenic effect in this cohort of workers exposed to AN. PMID:1506938

Swaen, G M; Bloemen, L J; Twisk, J; Scheffers, T; Slangen, J J; Sturmans, F

1992-08-01

173

Exposing private information by timing web applications  

Microsoft Academic Search

We show that the time web sites take to respond to HTTP requests can leak private information, using two dierent types of attacks. The first, direct timing, directly measures response times from a web site to expose private informa- tion such as validity of an username at a secured site or the number of private photos in a publicly viewable

Andrew Bortz; Dan Boneh

2007-01-01

174

Rural Canadian Youth Exposed to Physical Violence  

ERIC Educational Resources Information Center

Exposure to physical violence is an unfortunate reality for many Canadian youth as it is associated with numerous negative psychosocial effects. The study aims to assist in understanding resilience in rural Canadian youth exposed to physical violence. This is accomplished by identifying the importance of protective factors, as measured by the…

Laye, Adele M.; Mykota, David B.

2014-01-01

175

Reactions of latent prints exposed to blood.  

PubMed

We explored whether an undeveloped latent print (fingermark) exposed to blood and later developed by enhancement with blood reagents such as amido black (AB) or leucocrystal violet (LCV) could appear as a genuine blood mark. We examined three different experimental conditions. In Experiment I, fingermark residue only was tested, as a control to confirm that fingermark residue alone does not react with the blood reagents AB and LCV. Experiment II investigated whether latent fingermarks exposed to blood dilutions could be treated with AB or LCV and subsequently appear as a genuine blood mark enhanced with AB or LCV. Experiment III tested whether latent fingermarks exposed to whole blood could be processed with AB or LCV and subsequently appear as a genuine blood mark enhanced with AB or LCV. The present study found that indeed, fingermark residue alone does not react with the blood reagents AB and LCV. In Experiment II, an interaction occurred between the fingermark residue and the diluted blood that caused the ridges to appear a red color. In the present study, this interaction is called a faux blood mark. While the faux blood mark phenomenon occurred most often following exposure to diluted blood, it did not occur consistently, and a predictable pattern could not be established. However, the reaction occurred more frequently following extended fingermark residue drying times. Faux blood marks are distinguishable from genuine blood marks prior to enhancement with blood reagents. Following treatment with blood reagents, it became increasingly difficult to determine whether the enhanced mark was a genuine blood print or a latent fingermark exposed to diluted blood. Latent fingermarks exposed to whole blood often resulted in a void prior to enhancement, but following treatment with blood reagents, were difficult to distinguish from a genuine blood mark enhanced with blood reagents. PMID:23182867

Praska, Nicole; Langenburg, Glenn

2013-01-10

176

Surface contamination on LDEF exposed materials  

NASA Technical Reports Server (NTRS)

X-ray photoelectron spectroscopy (XPS) has been used to study the surface composition and chemistry of Long Duration Exposure Facility (LDEF) exposed materials including silvered Teflon (Ag/FEP), Kapton, S13GLO paint, quartz crystal monitors (QCM's), carbon fiber/organic matrix composites, and carbon fiber/Al Alloy composites. In each set of samples, silicones were the major contributors to the molecular film accumulated on the LDEF exposed surfaces. All surfaces analyzed have been contaminated with Si, O, and C; most have low levels (less than 1 atom percent) of N, S, and F. Occasionally observed contaminants included Cl, Na, K, P, and various metals. Orange/brown discoloration observed near vent slots in some Ag/FEP blankets were higher in carbon, sulfur, and nitrogen relative to other contamination types. The source of contamination has not been identified, but amine/amide functionalities were detected. It is probable that this same source of contamination account for the low levels of sulfur and nitrogen observed on most LDEF exposed surfaces. XPS, which probes 50 to 100 A in depth, detected the major sample components underneath the contaminant film in every analysis. This probably indicates that the contaminant overlayer is patchy, with significant areas covered by less that 100 A of molecular film. Energy dispersive x-ray spectroscopy (EDS) of LDEF exposed surfaces during secondary electron microscopy (SEM) of the samples confirmed contamination of the surfaces with Si and O. In general, particulates were not observed to develop from the contaminant overlayer on the exposed LDEF material surfaces. However, many SiO2 submicron particles were seen on a masked edge of an Ag/FEP blanket. In some cases such as the carbon fiber/organic matrix composites, interpretation of the contamination data was hindered by the lack of good laboratory controls. Examination of laboratory controls for the carbon fiber/Al alloy composites showed that preflight contamination was the most significant factor for all the contaminants generally detected at less than 1 atom percent, or detected only occasionally (i.e., all but Si, O, and C). Flight control surfaces, including sample backsides not exposed to space radiation or atomic oxygen flux, have accumulated some contamination on flight (compared to laboratory controls), but experimentally, the LDEF exposed surface contamination levels are generally higher for the contaminants Si and O. For most materials analyzed, Si contamination levels were higher on the leading edge surfaces than on the trailing edge surfaces. This was true even for the composite samples where considerable atomic oxygen erosion of the leading edge surfaces was observed by SEM. It is probable that the return flux associated with atmospheric backscatter resulted in enhanced deposition of silicones and other contaminants on the leading edge flight surfaces relative to the trailing edge. Although the Si concentration data suggested greater on-flight deposition of contaminants on the leading edge surfaces, the XPS analyses did not conclusively show different relative total thicknesses of flight deposited contamination for leading and trailing edge surfaces. It is possible that atomic oxygen reactions on the leading edge resulted in greater volatilization of the carbon component of the deposited silicones, effectively 'thinning' the leading edge deposited overlayer. Unlike other materials, exposed polymers such as Kapton and FEP-type Teflon had very low contamination on the leading edge surfaces. SEM evidence showed that undercutting of the contaminant overlayer and damaged polymer layers occurred during atomic oxygen erosion, which would enhance loss of material from the exposed surface.

Hemminger, Carol S.

1992-01-01

177

The EXPOSE-R Experiment ROSE-3 SPORES in artificial meteorites  

NASA Astrophysics Data System (ADS)

In the conducted experiment, spores of bacteria, fungi and ferns, especially adapted to survive extreme conditions, were either solely or embedded in artificial meteorites exposed to space environment in the ESA facility EXPOSE-R for 22 months (10.03.2009-21.02.2011). The experiment will provide experimental clues to the question whether meteorite material offers enough protection against the harsh environment of space for spores to survive a long-term stay in space. This question has received increased attention since the discovery of Martian meteorites has provided evidence that rocks can be transported from one planet to another in our solar

Panitz, C.; Horneck, G.; Rabbow, E.; Rettberg, P.; Reitz, G.

2011-10-01

178

Why not exposed extreme large telescopes?  

NASA Astrophysics Data System (ADS)

In designing and building extreme large optical telescopes of sizes above 10m main aperture diameter, the effort for protecting the telescope against environmental influences gets remarkable large in engineering efforts as well as in costs. Large radio telescopes of similar size are built in "exposed" design, which means, that the protections for the sensitive components are integrated into the telescope itself. Long ranging experience even for sub-millimeter wavelength radio telescopes is available. Why not thinking the unthinkable and design exposed extreme large optical telescopes? The paper describes methods to protect the optics, to protect the structures and mechanics, and to overcome the wind and temperature induced disturbances during operations. It shows also means to integrate large and comfortable rooms for the science instruments with free access during operations into the protected area of the telescope.

Kärcher, Hans J.; Süss, Martin

2006-06-01

179

Assessment of service exposed boiler tubes  

Microsoft Academic Search

Boiler tubes in power plants have finite life because of prolonged exposure to high temperature, stress and aggressive environment. Service-exposed platen superheater and reheater tubes (148,900 h) made of 2.25Cr-1 Mo steels in a 120 MW boiler of a thermal power plant were evaluated for remnant life. The investigation included hot tensile tests, hardness measurement, dimensional measurement, microscopy and creep

A. K. Ray; S. K. Sahay; B. Goswami

2003-01-01

180

Viability of bacterial spores exposed to hydrazine  

NASA Astrophysics Data System (ADS)

For the purposes of planetary protection, a series of experiments were performed to answer a long-standing question about the potential of bacterial contamination of interplanetary spacecraft from liquid hydrazine. Spores of Bacillus atrophaeus (ATCC No. 9372, also known as Bacillus subtilis var. niger, and BSN) were exposed to hydrazine and survivors were enumerated using the NASA standard planetary protection pour plate assay. Results indicate that bulk hydrazine rocket propellant may be considered free of living bacterial cells for planetary protection compliance.

Schubert, W.; Plett, G.; Yavrouian, A.; Barengoltz, J.

2008-09-01

181

Children Exposed to War\\/Terrorism  

Microsoft Academic Search

This paper reviews the prevalence of psychological morbidities in children who have been exposed to war-related traumas or terrorism as well as the diversity of war-related casualties and their associated psychological responses. The psychological responses to war-related stressors are categorized as (1) little or no reaction, (2) acute emotional and behavioral effects, and (3) long-term effects. Specific categories of war-related

Jon A. Shaw

2003-01-01

182

Genetic Alterations in Pesticide Exposed Bolivian Farmers  

PubMed Central

Background Pesticides are of concern in Bolivia because of increasing use. Frequent intoxications have been demonstrated due to use of very toxic pesticides, insufficient control of distribution and sale and little knowledge among farmers of protective measures and hygienic procedures. Method Questionnaires were applied and blood tests taken from 81 volunteers from La Paz County, of whom 48 were pesticide exposed farmers and 33 non-exposed controls. Sixty males and 21 females participated with a mean age of 37.3 years (range 17–76). Data of exposure and possible genetic damage were collected and evaluated by well known statistical methods, controlling for relevant confounders. To measure genetic damage chromosomal aberrations and the comet assay analysis were performed. Results Pesticide exposed farmers had a higher degree of genetic damage compared to the control group. The number of chromosomal aberrations increased with the intensity of pesticide exposure. Females had a lower number of chromosomal aberrations than males, and people living at altitudes above 2500 metres seemed to exhibit more DNA damage measured by the comet assay. Conclusions Bolivian farmers showed signs of genotoxic damage, probably related to exposure to pesticides. Due to the potentially negative long term health effects of genetic damage on reproduction and the development of cancer, preventive measures are recommended. Effective control with imports and sales, banning of the most toxic pesticides, education and information are possible measures, which could help preventing the negative effects of pesticides on human health and the environment. PMID:19662224

J?rs, Erik; Gonzales, Ana Rosa; Ascarrunz, Maria Eugenia; Tirado, Noemi; Takahashi, Catharina; Lafuente, Erika; Dos Santos, Raquel A; Bailon, Natalia; Cervantes, Rafael; O, Huici; Baelum, Jesper; Lander., Flemming

2007-01-01

183

Experimental investigations on freely exposed ducted radiators  

NASA Technical Reports Server (NTRS)

This report deals with the relation between the open areas, the drag, and the air flow as observed on freely exposed, ducted radiators - the air conductivity being modified from zero to one unit. In conjunction with theoretical results, the individual components of the drag of ducted radiators are discussed and general rules established for low-loss ducts. The influence of the wall thickness of the ducts, of the length ratio of the exit, and the effects of sonic velocity on diffusers are dealt with by special measurement.

Linke, W

1941-01-01

184

Children Exposed to Violence: Current Status, Gaps, and Research  

E-print Network

. Children exposed to domestic violence; 2. ChChildren Exposed to Violence: Current Status, Gaps, and Research Priorities WASHINGTON, D and Human Development, National Institutes of Health National Institute on Drug Abuse, National Institutes

Rau, Don C.

185

Behavioral changes in fish exposed to phytoestrogens.  

PubMed

We investigated the behavioral effects of exposure to waterborne phytoestrogens in male fighting fish, Betta splendens. Adult fish were exposed to a range of concentrations of genistein, equol, beta-sitosterol, and the positive control 17beta-estradiol. The following behaviors were measured: spontaneous swimming activity, latency to respond to a perceived intruder (mirror reflection), intensity of aggressive response toward a perceived intruder, probability of constructing a nest in the presence of a female, and the size of the nest constructed. We found few changes in spontaneous swimming activity, the latency to respond to the mirror, and nest size, and modest changes in the probability of constructing a nest. There were significant decreases, however, in the intensity of aggressive behavior toward the mirror following exposure to several concentrations, including environmentally relevant ones, of 17beta-estradiol, genistein, and equol. This suggests that phytoestrogen contamination has the potential to significantly affect the behavior of free-living fishes. PMID:16584819

Clotfelter, Ethan D; Rodriguez, Alison C

2006-12-01

186

Viability of bacterial spores exposed to hydrazine  

NASA Astrophysics Data System (ADS)

For the purposes of planetary protection a series of experiments were performed to answer a long-standing question about the potential of bacterial contamination of interplanetary spacecraft from liquid hydrazine Spores of Bacillus atrophaeus ATCC No 9372 also known as Bacillus subtilis var niger and BSN were exposed to hydrazine for various durations Then the survivors were enumerated using the NASA standard planetary protection pour plate assay It is important to note that in these experiments the hydrazine was removed prior to the assay This eliminated the possibility that the presence of hydrazine rather than a prior exposure was inhibiting germination and or reproduction Populations of 10 6 spores were eliminated within 30 minutes These results indicate that bulk hydrazine rocket propellant may be considered free of living bacterial cells for planetary protection compliance

Schubert, W.; Plett, G.; Yavrouian, A.; Barengoltz, J.

187

Population exposed to landslide risk in Italy  

NASA Astrophysics Data System (ADS)

Italy is one of the European countries most affected by landslides counting over 486,000 mass movements with a total area of 20,700 square kilometres equal to 6.9% of the national territory. Moreover Italy is a densely urbanized country: 8101 municipalities, about 200 inhabitants per sq. km, 16,000 km of rail network and 180,000 km of road network. Landslides caused more than 5000 fatalities in the last century and considerable damage to urban areas, transport infrastructure and facilities, environmental and cultural heritage. The aim of this work is to estimate the population exposed to landslide risk in Italy. The input data are: the Italian Landslide Inventory, the Italian Population Census data and the high-resolution Artificial surfaces-Imperviousness Layer (Geoland2). The Italian Landslide Inventory (Progetto IFFI) realised by ISPRA (Italian National Institute for Environmental Protection and Research) and the Regions and Self-governing Provinces, identifies landslides occurred in the national territory in accordance with standardized methods and using a detailed landslide mapping (1:10,000 scale). The 14th Population Census, made by ISTAT (Italian National Institute of Statistics) in 2001, contains data of resident population for the 382,534 census tracts in which Italy is divided. The pan-European high-resolution (HR) Artificial surfaces-Imperviousness Layer, realized using remote sensing data within the GMES initiative (Global Monitoring for Environment and Security) by European Commission and European Space Agency, contains the degree of imperviousness (between 0 and 100%). GIS overlay of this information layer (20 x 20 m grid) with census tracts has allowed the spatialization of population within urban settlements of each census tract. This methodology has been particularly useful in the case of rural census tracts characterized by large surface area and low population density. The methodology could be also applied to estimate the population exposed to other natural, environmental or technological risks.

Trigila, Alessandro; Iadanza, Carla; Munafò, Michele; Baiocco, Fabio; Marinosci, Ines; Chiocchini, Raffaella; Mugnoli, Stefano

2013-04-01

188

Risk and Protective Profiles Among Never Exposed, Single Form, and Multiple Form Violence Exposed Youth.  

PubMed

This investigation integrated violence exposure with critical risk and protective factors linked to healthy adolescent adaptation and transition into early adulthood. A racially diverse sample of 848 adolescents identified as at-risk for school drop-out were assessed for no, single, or multiple forms of violence exposure. MANOVA tests revealed that youth with single form victimization fared more poorly than never-exposed youth, and that multiple-form victimization held the greatest jeopardy to development. Youth with multiple-form victimization reported significantly elevated risk factors (emotional distress, life stress, suicide risk, risky behaviors) and lower protective factors (social support, school engagement, family structure) than both single-form and never-exposed youth. Implications are discussed for preventive and early intervention programming and for examining the transition of at-risk youth into young adulthood. PMID:21494415

Nurius, Paula S; Russell, Patricia L; Herting, Jerald R; Hooven, Carole; Thompson, Elaine A

2009-04-01

189

Comparative genomic hybridization study of arsenic-exposed and non-arsenic-exposed urinary transitional cell carcinoma  

SciTech Connect

To compare the differences in DNA aberrations between arsenic-exposed and non-arsenic-exposed transitional cell carcinoma (TCC), we analyzed 19 arsenic-exposed and 29 non-arsenic-exposed urinary TCCs from Chi-Mei Hospital using comparative genomic hybridization. DNA aberrations were detected in 42 TCCs including 19 arsenic-exposed and 23 non-arsenic-exposed TCCs. Arsenic-exposed TCCs had more changes than unexposed TCCs (mean {+-} SD, 6.6 {+-} 2.9 vs. 2.9 {+-} 2.2). Arsenic exposure was significantly associated with the number of DNA aberrations after adjustment for tumor stage, tumor grade and cigarette smoking in multiple regression analysis. The most frequent DNA gains, which were strikingly different between arsenic-exposed and non-arsenic-exposed TCCs, included those at 1p, 4p, 4q and 8q. A much higher frequency of DNA losses in arsenic-exposed TCCs compared with non-arsenic-exposed TCCs was observed in 10q, 11p and 17p. Chromosomal loss in 17p13 was associated not only with arsenic exposure, but also with tumor stage and grade. The p53 immunohistochemistry staining showed that chromosome 17p13 loss was associated with either p53 no expression (25%) or p53 overexpression (75%). The findings suggest that long-term arsenic exposure may increase the chromosome abnormality in TCC, and 17p loss plays an important role in arsenic-induced urinary carcinogenesis.

Hsu, L.-I [Genomics Research Center, Academia Sinica, Taipei, Taiwan (China); Chiu, Allen W. [Department of Urology, Taipei City Hospital Zhongxiao Branch, Taipei, Taiwan (China); Pu, Y.-S. [Department of Urology, National Taiwan University Hospital, Taipei, Taiwan (China); Wang, Y.-H. [School of Public Health, Taipei Medical University, Taipei, Taiwan (China); Huan, Steven K. [Division of Urology, Department of Surgery, Chi-Mei Medical Center, Tainan, Taiwan (China); Hsiao, C.-H. [Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan (China); Hsieh, F.-I [School of Public Health, Taipei Medical University, Taipei, Taiwan (China); Chen, C.-J. [Genomics Research Center, Academia Sinica, Taipei, Taiwan (China)], E-mail: hsu277@yahoo.com.tw

2008-03-01

190

Suppression tuning in noise-exposed rabbits.  

PubMed

Psychophysical, basilar-membrane (BM), and single nerve-fiber tuning curves, as well as suppression of distortion-product otoacoustic emissions (DPOAEs), all give rise to frequency tuning patterns with stereotypical features. Similarities and differences between the behaviors of these tuning functions, both in normal conditions and following various cochlear insults, have been documented. While neural tuning curves (NTCs) and BM tuning curves behave similarly both before and after cochlear insults known to disrupt frequency selectivity, DPOAE suppression tuning curves (STCs) do not necessarily mirror these responses following either administration of ototoxins [Martin et al., J. Acoust. Soc. Am. 104, 972-983 (1998)] or exposure to temporarily damaging noise [Howard et al., J. Acoust. Soc. Am. 111, 285-296 (2002)]. However, changes in STC parameters may be predictive of other changes in cochlear function such as cochlear immaturity in neonatal humans [Abdala, Hear. Res. 121, 125-138 (1998)]. To determine the effects of noise-induced permanent auditory dysfunction on STC parameters, rabbits were exposed to high-level noise that led to permanent reductions in DPOAE level, and comparisons between pre- and postexposure DPOAE levels and STCs were made. Statistical comparisons of pre- and postexposure STC values at CF revealed consistent basal shifts in the frequency region of greatest cochlear damage, whereas thresholds, Q10dB, and tip-to-tail gain values were not reliably altered. Additionally, a large percentage of high-frequency lobes associated with third tone interference phenomena, that were exhibited in some data sets, were dramatically reduced following noise exposure. Thus, previously described areas of DPOAE interference above f2 may also be studied using this type of experimental manipulation [Martin et al., Hear. Res. 136, 105-123 (1999); Mills, J. Acoust. Soc. Am. 107, 2586-2602 (2002)]. PMID:12880041

Howard, MacKenzie A; Stagner, Barden B; Foster, Paul K; Lonsbury-Martin, Brenda L; Martin, Glen K

2003-07-01

191

Foster placed children prenatally exposed to poly-substances  

Microsoft Academic Search

This paper reports on a prospective, longitudinal study of children prenatally exposed to poly-substances, who were reared under minimal postnatal risk conditions. The aim of the study was to examine whether the substance-exposed group exhibited a higher level of attention-related problems than a group of age-matched, nonexposed children. The substance-exposed children (n = 42) evinced significant elevated levels of impulsivity

K. Slinning

2004-01-01

192

Synthesizing Regularity Exposing Attributes in Large Protein Databases  

E-print Network

This thesis describes a system that synthesizes regularity exposing attributes from large protein databases. After processing primary and secondary structure data, this system discovers an amino acid representation ...

de la Maza, Michael

1993-05-01

193

Ecophysiological tolerance of duckweeds exposed to copper.  

PubMed

Although essential for plants, copper can be toxic when present in supra-optimal concentrations. Metal polluted sites, due to their extreme conditions, can harbour tolerant species and/or ecotypes. In this work we aimed to compare the physiological responses to copper exposure and the uptake capacities of two species of duckweed, Lemna minor (Lm(EC1)) and Spirodela polyrrhiza (SP), from an abandoned uranium mine with an ecotype of L. minor (Lm(EC2)) from a non-contaminated pond. From the lowest Cu concentration exposure (25microM) to the highest (100microM), Lm(EC2) accumulated higher amounts of copper than Lm(EC1) and SP. Dose-response curves showed that Cu content accumulated by Lm(EC2) increases linearly with Cu treatment concentrations (r(2)=0.998) whereas quadratic models were more suitable for Lm(EC1) and SP (r(2)=0.999 and r(2)=0.998 for Lm(EC1) and SP, respectively). A significant concentration-dependent decline of chlorophyll a (chl a) and carotenoid occurred as a consequence of Cu exposure. These declines were significant for Lm(EC2) exposed to the lowest Cu concentration (25microM) whereas for Lm(EC1) and SP a significant decrease in chl a and carotenoids was observed only at 50 and 100microM-Cu. Electric conductivity (EC) and malondialdehyde (MDA) content increased after Cu exposure, indicating oxidative stress. Significant increase of EC was observed in Lm(EC2) for all Cu concentrations whereas the increase for Lm(EC1) and SP became significant only after an exposure to 50microM-Cu. On the contrary, for Lm(EC1), SP, and Lm(EC2), MDA content significantly increased even at the lowest concentration. Protein content and catalase (CAT) activity showed a decrease with an increase in Cu concentration. For the species Lm(EC1) and SP, a significant effect of copper on CAT activity was observed only at the highest concentration (100microM-Cu) whereas, for Lm(EC2), this effect started to be significant after an exposure to 50microM-Cu. Superoxide dismutase (SOD) activity increased with increasing concentrations of Cu, with a very similar trend between the three populations of duckweed. However, due to the facts that enzyme activity is expressed as units of activity per gram of protein and that protein content decreased with Cu exposure, the increase in SOD activity might partly result from a relative increase of this enzyme inside the pool of proteins. Consequently, the results obtained in our experimental conditions strongly suggest that duckweed species from the uranium-polluted area have developed mechanisms to cope with metal toxicity and that this tolerance is based on the existence of protective mechanism to limit the metal uptake rather than on an enhancement of the antioxidative metabolism. PMID:19027182

Kanoun-Boulé, Myriam; Vicente, Joaquim A F; Nabais, Cristina; Prasad, M N V; Freitas, Helena

2009-01-18

194

Reactivity and Regulation in Children Prenatally Exposed to Cocaine  

ERIC Educational Resources Information Center

Children prenatally exposed to cocaine may be at elevated risk for adjustment problems in early development because of greater reactivity and reduced regulation during challenging tasks. Few studies have examined whether cocaine-exposed children show such difficulties during the preschool years, a period marked by increased social and cognitive…

Dennis, Tracy; Bendersky, Margaret; Ramsay, Douglas; Lewis, Michael

2006-01-01

195

31. VIEW OF ROOM 212 LOOKING NORTHWEST TOWARDS EXPOSED STUD ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

31. VIEW OF ROOM 212 LOOKING NORTHWEST TOWARDS EXPOSED STUD WALL THAT SERVES AS DIVIDER TO ROOM 211. EXPOSED TRUSSWORK VISIBLE THROUGH TO NEXT ROOM. WOOD PANELED WALLS ARE PAINTED; FLOORS ARE WOOD. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

196

Altered levels of urinary prostanoids in lead-exposed workers  

Microsoft Academic Search

This paper describes the alteration of the urinary excretion of prostanoids in workers occupationally exposed to lead. For this purpose, the following groups were studied: Group 1 (n = 62): controls; Group 2 (n = 29): risk group; and Group 3 (n = 69): exposed group. Urine samples were collected for prostanoid analysis and lead blood levels were analyzed. Our

G. Hotter; L. M. Fels; D. Closa; J. Roselló; H. Stolte; E. Gelpí

1995-01-01

197

Neurobehavior in preterm neonates exposed to cocaine, alcohol, and tobacco  

Microsoft Academic Search

Neonatal neurobehavioral development was investigated in a sample of 20 hospitalized, prenatally cocaine-exposed preterm infants and 20 matched non-exposed controls. Prenatal cocaine exposure was related to reductions in attention performance that remained apparent at 36 weeks conceptional age. There was no impact of prenatal cocaine exposure on the rate of change in attention proficiency. In utero alcohol exposure was associated

David J. Francis

1997-01-01

198

Foliar Lead Uptake by Lettuce Exposed to Atmospheric Fallouts  

E-print Network

Foliar Lead Uptake by Lettuce Exposed to Atmospheric Fallouts G A ¨E L L E U Z U , S O P H I E S O gardens near industrial plants. The mechanisms of foliar uptake of lead by lettuce (Lactuca sativa) exposed to the atmospheric fallouts of a lead-recycling plant were studied. After43daysofexposure

Mailhes, Corinne

199

The Psychobiology of Children Exposed to Marital Violence  

ERIC Educational Resources Information Center

We examined the psychological and physiological functioning of a community sample of children exposed to marital violence, comparing them to a clinical comparison group without marital violence exposure. Results replicated past findings of elevated levels of trauma symptomatology in this population. Further, children exposed to marital violence…

Saltzman, Kasey M.; Holden, George W.; Holahan, Charles J.

2005-01-01

200

Children Exposed in Utero to Illegal Drugs: Education's Newest Crisis.  

ERIC Educational Resources Information Center

This bulletin highlights topics addressed at a National Association of State Directors of Special Education (NASDSE) Action Seminar on Infants Exposed to Illicit Drugs and Alcohol in Utero. The incidence of babies being born exposed to cocaine and other illicit drugs is outlined, and it is concluded that numbers appear to be on the rise. The…

Liaison Bulletin, 1992

1992-01-01

201

Animal cruelty by children exposed to domestic violence  

Microsoft Academic Search

ObjectiveThe first objective of this study was to determine if children exposed to domestic violence were significantly more likely to be cruel to animals than children not exposed to violence. The second was to determine if there were significant age and gender differences between children who were and were not cruel to animals.

Cheryl L. Currie

2006-01-01

202

Strongly Exposed Points in the Ball of the Bergman Space  

Microsoft Academic Search

We investigate which boundary points in the closed unit ball of the Bergman space A1 are strongly exposed. This requires study of the Bergman projection and its kernel, the annihilator of Bergman space. We show that all polynomials in the boundary of the unit ball are strongly exposed.

Paul Beneker; J. J. O. O. Wiegerinck

2005-01-01

203

Cerebellar Histogenesis in Rats Exposed to 2450 MHz Microwave Radiation,  

National Technical Information Service (NTIS)

Pregnant rats were either exposed or sham exposed from day 13 of gestation until birth to 2450 MHz linearly polarized microwaves at 10 mW/sq cm. A third matching group served as cage control. After birth, the pups were kept with their mothers for 21 days ...

E. N. Albert

1988-01-01

204

Somatosensory evoked potentials in workers exposed to toluene and styrene.  

PubMed Central

Somatosensory evoked potentials (SEPs) were used to evaluate possible subclinical impairment of the nervous system due to occupational exposure to toluene and styrene. A group of 36 rotogravure printers with severe exposure to toluene, 20 workers with severe exposure to styrene in a glass laminate manufacturing plant, and a comparison group of healthy subjects were studied. The severity of exposure was documented by measurements of toluene and styrene concentrations in breathing zone air, by hippuric acid concentration in urine in the group exposed to toluene, and by urinary mandelic acid concentration in the group exposed to styrene. Somatosensory evoked potentials were measured by stimulation of the median nerve at the wrist and the tibial nerve at the ankle. Peripheral conduction velocities (CVs) in both extremities and central conduction time (CCT) after tibial nerve stimulation were significantly decreased in both exposed groups. Significantly prolonged latencies of peripheral and cortical SEPs to median nerve stimulation as well as cortical SEPs to tibial nerve stimulation were found in workers exposed to styrene. Some abnormalities in SEPs at peripheral or spinal and cortical levels were found in eight workers exposed to toluene and six workers exposed to styrene. Of these, in three workers exposed to toluene and two to styrene increased CCT and delayed latencies of cortical responses at normal conduction values in the periphery were found. A trend for increased frequency of abnormal SEPs with duration of exposure to toluene and styrene and alcohol abuse was found. Abnormalities in SEPs in the exposed groups are most probably of multifactorial origin. Central SEP abnormalities in both exposed groups could indicate early signs of subclinical dysfunction at spinal and cortical levels and could be due to toluene or styrene exposure probably potentiated by alcohol consumption in the group exposed to toluene. PMID:8329318

St?tkárová, I; Urban, P; Procházka, B; Lukás, E

1993-01-01

205

ENTERIC PARASITES IN WORKERS OCCUPATIONALLY EXPOSED TO SEWAGE  

EPA Science Inventory

To determine if parasitic infections occur more frequently among workers exposed to wastewater than among controls, parasitologic examinations were performed on stool specimens collected over a 12-month period from sewer and highway maintenance workers. Three of 56 sewer maintena...

206

TERATOGENESIS, TOXICITY, AND BIOCONCENTRATION IN FROGS EXPOSED TO DIELDRIN  

EPA Science Inventory

Teratogenesis, acute and chronic toxicity, and bioconcentration were investigated in various like stages of African clawed frogs (Xenopus laevis), bullfrogs (Rana catesbeiana) and leopard frogs (Rana pipiens) exposed to aqueous dieldrin in static-renewal and continuous-flow tests...

207

3. VIEW EAST, WEST ELEVATION, DETAIL OF EXPOSED TIMBER FRAMING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. VIEW EAST, WEST ELEVATION, DETAIL OF EXPOSED TIMBER FRAMING - Stiegel House, East side State Route 419, North of intersection of State Route 419 & State Route 897 (Heidelberg Township), Schaefferstown, Lebanon County, PA

208

18. VIEW, LOOKING SOUTHWEST, SHOWING EXPOSED STEEL FRAMING OF WATERFRONT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

18. VIEW, LOOKING SOUTHWEST, SHOWING EXPOSED STEEL FRAMING OF WATERFRONT ELEVATION - Central Railroad of New Jersey, Jersey City Ferry Terminal, Johnson Avenue at Hudson River, Jersey City, Hudson County, NJ

209

46 CFR 108.223 - Guards on exposed equipment.  

Code of Federal Regulations, 2010 CFR

...Guards on exposed equipment. Each unit must have hand covers, guards, or rails installed on all belts, gears, shafts, pulleys, sprockets, spindles, flywheels or other reciprocating, rotating or moving parts of machinery or equipment normally...

2010-10-01

210

VERTEBRAL DYSPLASIA IN YOUNG FISH EXPOSED TO THE HERBICIDE TRIFLURALIN  

EPA Science Inventory

Sheepshead minnows, Cyprinodon variegatus Lacepede, exposed to 5-5 to 31 micrograms/l of the herbicide trifluralin, throughout their first 28 days of life, developed a heretofore, undescribed vertebral dysplasia. This dysplasia consisted of semisymmetrical hypertrophy of vertebra...

211

Continuous ambulatory electrocardiography among workers exposed to methylmethacrylate.  

PubMed

Methylmethacrylate (MMA), a widely used monomer in the manufacture of acrylic polymers, has been reported to cause cardiac troubles in industrial workers. The effects of MMA on the heart was assessed by continuous ambulatory electrocardiographic records. The study was performed in 22 occupationally exposed workers and in 18 healthy controls. Our study did not support the hypothesis that MMA is responsible for cardiomyodystrophy. However, supraventricular and ventricular ectopic beats were significantly more frequent among exposed workers versus controls (P < 0.01). Moreover, repolarization changes such as large T waves were noted only in exposed workers (eight cases against none in the control group). Although there was no clear connection between MMA exposure and the recorded cardiac changes in the exposed group, the role of MMA cannot be totally excluded. PMID:1283158

Marez, T; Shirali, P; Haguenoer, J M

1992-01-01

212

RESPONSE OF MICROBIAL COMMUNITIES EXPOSED TO PENTACHLOROPHENOL IN ESTUARINE SEDIMENTS  

EPA Science Inventory

Effects of environmental contaminants, including pentachlorophenol (PCP), a widely-used wood preserving agent, on estuarine microbial community composition and processes were evaluated. Slurries of estuarine sediments were exposed to PCP at environmentally relevant concentrations...

213

TRANSCRIPTIONAL RESPONSES OF MOUSE EMBRYO CULTURES EXPOSED TO BROMOCHLOROACETIC ACID  

EPA Science Inventory

Transcriptional responses of mouse embryo cultures exposed to bromochloroacetic acid Edward D. Karoly?*, Judith E. Schmid* and E. Sidney Hunter III* ?Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina and *Reproductive Tox...

214

American Doctor Exposed to Ebola Admitted to NIH Hospital  

MedlinePLUS

... page, please enable JavaScript. American Doctor Exposed to Ebola Admitted to NIH Hospital The patient was working ... 2014) Monday, September 29, 2014 Related MedlinePlus Pages Ebola Health Facilities MONDAY, Sept. 29, 2014 (HealthDay News) -- ...

215

Synthesizing Regularity Exposing Attributes in Large Protein Databases.  

National Technical Information Service (NTIS)

This thesis describes a system that synthesizes regularity exposing attributes from large protein databases. After processing primary and secondary structure data, this system discovers an amino acid representation that captures what are thought to be the...

M. De La Maza

1993-01-01

216

Hepatic ultrasonic changes in workers exposed to perchloroethylene  

Microsoft Academic Search

OBJECTIVE--To determine if subclinical hepatotoxicity is associated with exposure to perchloroethylene at concentrations commonly experienced in the workplace, and whether surveillance with serum hepatic transaminase activity underestimates such effects. METHODS--Hepatic parenchymal echogenicity on ultrasonography and serum hepatic transaminase activity were compared in 29 community based dry cleaning operators exposed to perchloroethylene, and a control group of 29 non-exposed laundry workers.

C A Brodkin; W Daniell; H Checkoway; D Echeverria; J Johnson; K Wang; R Sohaey; D Green; C Redlich; D Gretch

1995-01-01

217

Blood and serum analyses of cold?exposed chipmunks  

Microsoft Academic Search

To understand the adaptational strategy of Korean chipmunks (Tamias sibiricus) to cold temperature, blood and serum properties, and thyroid gland activity of cold?exposed chipmunks were examined. The number of erythrocytes and hemoglobin concentration increased, but platelets decreased in cold?exposed chipmunks compared with warm chipmunks. Serum total protein levels increased at early phase of cold?exposure, and decreased thereafter. Plasma glucose levels

Young Gi Gil; Jun Hyuk Lee; Young Hyun Choi; Dae Yeon Moon; Un Bock Jo; Byung Tae Choi

2003-01-01

218

Neurasthenic symptoms in workers occupationally exposed to jet fuel.  

PubMed

Long-term exposure to petroleum distillation products (e.g. jet fuel) has been suggested to cause chronic mental and neurological symptoms. In the present "cross-sectional epidemiological study" the extent of neuropsychiatric ill-health in 30 workers exposed to jet fuel was compared with that in 60 non-exposed matched controls. Standardized medical interviews showed a higher occurrence of neurasthenic symptoms in exposed subjects (P less than 0.001). The result was confirmed by examination of the medical records kept by the factory physician (P less than 0.01). The prevalence of psychiatric symptoms was assessed with a rating scale of 37 items (a modified CPRS). Again, the exposed workers scored higher than the controls (P less than 0.001), particularly regarding the neurasthenic symptoms, i.e. fatigue, anxiety, mood changes, memory difficulties, and various psychosomatic symptoms (P less than 0.01). The results could neither be explained by observer's bias, nor by a greater susceptibility for mental disorders in the exposed subjects. We therefore conclude that occupational exposure to jet fuel vapours around the present threshold limit values may induce a neurasthenic syndrome. PMID:474176

Knave, B; Mindus, P; Struwe, G

1979-07-01

219

Epidemiological survey of workers exposed to inorganic germanium compounds  

PubMed Central

OBJECTIVES—To assess occupational exposure to inorganic germanium (Ge) in workers from a producing plant, and to assess the health of these workers, with a special focus on respiratory, kidney, and liver functions.?METHODS—Cross sectional study of 75 workers exposed to Ge and 79 matched referents. Exposure was characterised by measuring air and urine concentrations of the element during a typical working week, and health was assessed by a questionnaire, clinical examination, lung function testing, chest radiography, and clinical chemistry in serum and urine, including high and low molecular weight urinary proteins.?RESULTS—Airborne concentrations of Ge (inhalable fraction) ranged from 0.03 to 300 µg/m, which was reflected by increased urinary excretion of Ge (0.12-200 µg/g creatinine, after the shift at the end of the working week). Lung, liver, and haematological variables were not significantly different between referents and workers exposed to Ge. A slightly higher urinary concentration of high molecular weight proteins (albumin and transferrin) was found in workers exposed to Ge, possibly reflecting subclinical glomerular changes. No relation was found between the intensity or duration of exposure and the urinary concentration of albumin. No difference between referents and workers exposed to Ge was found for other renal variables.?CONCLUSIONS—Measurement of urinary Ge can detect occupational exposure to inorganic Ge and its compounds. It is prudent to recommend the monitoring of renal variables in workers exposed to Ge.???Keywords: inorganic germanium; occupational exposure; biological monitoring PMID:10810110

Swennen, B; Mallants, A; Roels, H; Buchet, J; Bernard, A; Lauwerys, R; Lison, D

2000-01-01

220

Cytogenetic investigation of subjects professionally exposed to radiofrequency radiation.  

PubMed

Nowadays, virtually everybody is exposed to radiofrequency radiation (RFR) from mobile phone base station antennas or other sources. At least according to some scientists, this exposure can have detrimental health effects. We investigated cytogenetic effects in peripheral blood lymphocytes from subjects who were professionally exposed to mobile phone electromagnetic fields in an attempt to demonstrate possible RFR-induced genetic effects. These subjects can be considered well suited for this purpose as their RFR exposure is 'normal' though rather high, and definitely higher than that of the 'general population'. The alkaline comet assay, sister chromatid exchange (SCE) and chromosome aberration tests revealed no evidence of RFR-induced genetic effects. Blood cells were also exposed to the well known chemical mutagen mitomycin C in order to investigate possible combined effects of RFR and the chemical. No cooperative action was found between the electromagnetic field exposure and the mutagen using either the comet assay or SCE test. PMID:16481348

Maes, Annemarie; Van Gorp, Urbain; Verschaeve, Luc

2006-03-01

221

An XPS study of space-exposed polyimide film  

NASA Technical Reports Server (NTRS)

X-ray photoelectron spectroscopy was used to assess changes induced in the surface chemistry of Kapton H (Du Pont Trademark) polyimide strips exposed to the low Earth orbit environment at the space-end of the LDEF satellite on Experiment A0133. Results from flight specimens are compared to material cut from the same lot and stored at room temperature under standard atmospheric conditions. One notable difference was a nearly two-fold increase in surface oxygen (atom-percent composition) for specimens exposed to the direct space environment as compared to controls. In addition, space exposed specimens contained distinct silicon peaks (2p 103.2 eV and 2s 154.2 eV) in their spectra. These peaks were absent in control spectra. It is likely that the increase in oxygen is associated with the silicon. This is in agreement with reports of widespread silicon contamination throughout the LDEF satellite.

Lee, Myung; Rooney, William; Whiteside, James

1993-01-01

222

Decision support for subjects exposed to heat stress.  

PubMed

The physiological and activity strain index (PASI) has been developed to improve the online decision support for workers exposed to heat stress. Fire fighters (smoke divers) which are exposed to both heat-stress and high-risk situations have been used as test case. PASI combines a modified version of the relatively well-known physiological strain index (PSI) with activity data from accelerometers. The algorithm has been developed based on tests in a laboratory, and it has been verified in two field tests performed by smoke divers exposed to heat stress. The verification demonstrates that it is possible to distinguish between high- and low-risk situations when data from accelerometers are added to the situation analysis. This indicates that PASI can contribute to an improved risk assessment and online decision support for smoke divers compared to using PSI alone. PMID:24235112

Seeberg, Trine M; Vardøy, Astrid-Sofie B; Taklo, Maaike M Visser; Austad, Hanne Opsahl

2013-03-01

223

Study of the lipoprotein pattern among workers exposed to lead.  

PubMed

Occupational exposure to lead fumes constitutes a serious problem in Egypt, since a considerable number of workers might be involved in its deleterious effect. The present study aimed to elucidate the effect of lead exposure on the lipoprotein pattern of exposed workers. The study has been carried out in a plant manufacturing lead batteries. It consists of 89 workers exposed to lead and 25 control subjects. Fasting blood samples were collected for the determination of serum lipoprotein pattern and their cholesterol and phospholipid content. Levels of lead in blood and delta amino levulinic acid in urine have been determined as biological indices of lead exposure. Lead exposure caused mainly a cumulative effect on the cholesterol and phospholipid content of lipoproteins since only workers exposed for more than 10 years showed significant changes. These changes might be referred to the effect of lead exposure on liver and/or on trace metal metabolism. PMID:2519975

el-Gazzar, R M; el-Hefny, S A; Noweir, K H; Shamy, M Y

1989-01-01

224

Lung cancer in rats exposed to fibrogenic dusts  

SciTech Connect

Fischer-344 rats were exposed to quartz dusts and to quartz-bearing oil shale dusts in long-term inhalation studies. Aerosol concentrations of 12 mg/m/sup 3/ and 152-176 mg/m/sup 3/ for quartz and shale dusts, respectively, were used in exposure regimens lasting up to two years. Pulmonary fibrosis was observed in most animals surviving beyond 400 days. Adenocarcinomas and epidermoid carcinomas of the lung were observed in animals from all exposure groups, including those exposed to quartz alone. The pulmonary tumors were a late effect, with the earliest lung tumor being observed after 651 days. 13 references, 10 figures, 4 tables.

Holland, L.M.; Wilson, J.S.; Tillery, M.I.; Smith, D.M.

1984-01-01

225

Temporal changes in respiratory dynamics in mice exposed to phosgene.  

PubMed

One hallmark of phosgene inhalation toxicity is the latent formation of life-threatening, noncardiogenic pulmonary edema. The purpose of this study was to investigate the effect of phosgene inhalation on respiratory dynamics over 12 h. CD-1 male mice, 25-30 g, were exposed to 32 mg/m(3) (8 ppm) phosgene for 20 min (640 mg min/m(3)) followed by a 5-min air washout. A similar group of mice was exposed to room air for 25 min. After exposure, conscious mice were placed unrestrained in a whole-body plethysmograph to determine breathing frequency (f), inspiration (Ti) and expiration (Te) times, tidal volume (TV), minute ventilation (MV), end inspiratory pause (EIP), end expiratory (EEP) pause, peak inspiratory flows (PIF), peak expiratory flows (PEF), and a measure of bronchoconstriction (Penh). All parameters were evaluated every 15 min for 12 h. Bronchoalveolar lavage fluid (BALF) protein concentration and lung wet/dry weight ratios (W/D) were also determined at 1, 4, 8, and 12 h. A treatment x time repeated-measures two-way analysis of variance (ANOVA) revealed significant differences between air and phosgene for EEP, EIP, PEF, PIF, TV, and MV, p < or =.05, across 12 h. Phosgene-exposed mice had a significantly longer mean Ti, p < or =.05, compared with air-exposed mice over time. Mice exposed to phosgene showed marked increases (approximately double) in Penh across all time points, beginning at 5 h, when compared with air-exposed mice, p < or =.05. BALF protein, an indicator of air/blood barrier integrity, and W/D were significantly higher, 10- to 12-fold, in phosgene-exposed than in air-exposed mice 4-12 h after exposure, p

Sciuto, Alfred M; Lee, Robyn B; Forster, Jeffry S; Cascio, Matthew B; Clapp, Diana L; Moran, Ted S

2002-05-01

226

Study of indium tin oxide films exposed to atomic axygen  

NASA Technical Reports Server (NTRS)

A qualitative simulation of the effects of atomic oxygen has been conducted on indium tin oxide (ITO) films prepared by dc sputtering onto room-temperature substrates, by exposing them to an RF-excited oxygen plasma and characterizing the resulting changes in optical, electrical, and structural properties as functions of exposure time with ellipsometry, spectrophotometry, resistivity, and X-ray measurements. While the films thus exposed exhibit reduced resistivity and optical transmission; both of these effects, as well as partial crystallization of the films, may be due to sample heating by the plasma. Film resistivity is found to stabilize after a period of exposure.

Snyder, Paul G.; De, Bhola N.; Woollam, John A.; Coutts, T. J.; Li, X.

1989-01-01

227

Exposing Pliocene Lignite Bed Near a BEN Village  

USGS Multimedia Gallery

Nikola Pavlovic, a kidney specialist and a USGS collaborator on Balkan endemic nephropathy (BEN) studies from Serbia, is shown exposing a small Pliocene lignite bed near a BEN village in the Vratza area of Bulgaria. The Pliocene lignite seams vary greatly in size and extent. BEN villages are always ...

2009-09-10

228

CYTOGENETIC STUDIES OF MICE EXPOSED TO STYRENE BY INHALATION  

EPA Science Inventory

The published data for the in vivo genotoxicity of styrene (STY) are equivocal. o evaluate the clastogenicity and sister chromatid exchange (SCE)-inducing potential of STY in vivo under carefully controlled conditions, 36C3F1 female mice were exposed by inhalation for 6 hours/day...

229

Genetic Predisposition for Dermal Problems in Hexavalent Chromium Exposed Population  

PubMed Central

We studied the effect of genetic susceptibility on hexavalent chromium induced dermal adversities. The health status of population was examined from the areas of Kanpur (India) having the elevated hexavalent chromium levels in groundwater. Blood samples were collected for DNA isolation to conduct polymorphic determination of genes, namely: NQO1 (C609T), hOGG1 (C1245G), GSTT1, and GSTM1 (deletion). Symptomatic exposed subjects (n = 38) were compared with asymptomatic exposed subjects (n = 108) along with asymptomatic controls (n = 148) from a non contaminated reference community. Exposed symptomatic group consisted of 36.8% subjects who were GSTM1 null genotyped as compared to asymptomatic where only 19.4% subjects were null. The exposed subjects with GSTM1 null genotype were more susceptible to dermal adversities in comparison with wild genotyped subjects (OR?=?2.42; 95% CI?=?1.071–5.451). Age, smoking, gender or duration of residence were not found to have any confounding effect towards this association. Association with other genes was not statistically significant, nonetheless, possible contribution by these genes cannot be ruled out. In conclusion, variation in the polymorphic status of GSTM1 gene may influence dermal outcomes among residents from Cr(VI) contaminated areas. Further studies are therefore, needed to examine these observations among different population groups. PMID:22919465

Sharma, Priti; Bihari, Vipin; Agarwal, Sudhir K.; Goel, Sudhir K.

2012-01-01

230

Comparison of exposed dentinal surfaces resulting from abrasion and erosion  

Microsoft Academic Search

The aim of this study was to compare the shape of exposed dentinal surfaces caused by abrasion and erosion with a view to developing a diagnostic clinical test. The study material consisted of 80 natural teeth and 129 dental models obtained from Australian Aborigines known to display considerable dental abrasion due to their diet, and dental models of 37 Caucasians

Emma Jane Bell; John Kaidonis; Grant Townsend; Lindsay Richards

1998-01-01

231

Asthma in exercising children exposed to ozone: a cohort study  

Microsoft Academic Search

Summary Background Little is known about the effect of exposure to air pollution during exercise or time spent outdoors on the development of asthma. We investigated the relation between newly-diagnosed asthma and team sports in a cohort of children exposed to different concentrations and mixtures of air pollutants. Methods 3535 children with no history of asthma were recruited from schools

Rob McConnell; Kiros Berhane; Frank Gilliland; Stephanie J London; Talat Islam; W James Gauderman; Edward Avol; Helene G Margolis; John M Peters

2002-01-01

232

A Care Coordination Program for Substance-Exposed Newborns  

ERIC Educational Resources Information Center

The Vulnerable Infants Program of Rhode Island (VIP-RI) was established as a care coordination program to promote permanency for substance-exposed newborns in the child welfare system. Goals of VIP-RI were to optimize parents' opportunities for reunification and increase the efficacy of social service systems involved with families affected by…

Twomey, Jean E.; Caldwell, Donna; Soave, Rosemary; Fontaine, Lynne Andreozzi; Lester, Barry M.

2011-01-01

233

Dental caries in Faroese children exposed to polychlorinated biphenyls  

Microsoft Academic Search

The effects of exposure to polychlorinated biphenyls (PCBs) on dental caries of first permanent molars in children in the Faroe Islands, where the population is exposed to PCBs in their traditional diet, were evaluated. This study was part of a cohort study aimed at determining developmental risks resulting from the consumption of contaminated seafood. One hundred and fourteen children from

Janja Jan; Katrin Reinert

2008-01-01

234

BRAIN CHOLINESTERASE ACTIVITY OF BOBWHITE ACUTELY EXPOSED TO CHLORPYRIFOS  

EPA Science Inventory

Northern bobwhite, Colinus virginianus, were orally dosed with the organophosphorus insecticide chlorpyrifos to examine effects on brain cholinesterase (AChE) activity. wo-week-old quail were acutely exposed and euthanized at selected times following gavage-dosing, ranging from 1...

235

Exposing Behavioral Differences in Cross-Language API Mapping Relations  

E-print Network

Exposing Behavioral Differences in Cross-Language API Mapping Relations Hao Zhong1 , Suresh translation of many call sites of API elements (i.e., classes, methods, and fields of API libraries). API source API elements and their equiv- alent target API elements. However, in an API mapping relation

Xie, Tao

236

Profiles of Reactivity in Cocaine-Exposed Children  

ERIC Educational Resources Information Center

This study explored the possibility that specific, theoretically consistent profiles of reactivity could be identified in a sample of cocaine-exposed infants and whether these profiles were associated with a range of infant and/or maternal characteristics. Cluster analysis was used to identify distinct groups of infants based on physiological,…

Schuetze, Pamela; Molnar, Danielle S.; Eiden, Rina D.

2012-01-01

237

RESPONSE OF BUSH BEAN EXPOSED TO ACID MIST  

EPA Science Inventory

Bush bean plants (Phaseolus vulgaris L. cv. Contender) were treated once a week for six weeks with simulated acid mist at five pH ranging from 5.5 to 2.0. Leaf injury developed on plants exposed to acid concentrations below pH 3 and many leaves developed a flecking symptom simila...

238

Predictors of motor development in children prenatally exposed to cocaine  

Microsoft Academic Search

The current study examined the pattern of motor development across the first 18 months of life in infants with in utero exposure to cocaine to determine how prenatal drug effects and level of exposure relates to motor development. Motor development was examined at 1, 4, 12, and 18 months of age (corrected for prematurity). Infants were divided into cocaine exposed

Cynthia Miller-Loncar; Barry M. Lester; Ronald Seifer; Linda L. Lagasse; Charles R. Bauer; Seetha Shankaran; Henrietta S. Bada; Linda L. Wright; Vincent L. Smeriglio; Rosemarie Bigsby; Jing Liu

2005-01-01

239

3. First floor of rear ell: view of exposed framing ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. First floor of rear ell: view of exposed framing on north wall, floor, and ceiling, looking north - McCrone House, Rear Ell, New Castle Hundred, 1 mile South of intersection of U.S. Route 13 & Route 40, west of Route 13, New Castle, New Castle County, DE

240

Spatial Memory Perfomance of Wistar Rats Exposed to Mobile Phone  

PubMed Central

INTRODUCTION With the tremendous increase in number of mobile phone users world wide, the possible risks of this technology have become a serious concern. OBJECTIVE We tested the effects of mobile phone exposure on spatial memory performance. MATERIALS AND METHODS Male Wistar rats (10–12 weeks old) were exposed to 50 missed calls/day for 4 weeks from a GSM (900/1800MHz) mobile phone in vibratory mode (no ring tone). After the experimental period, the animals were tested for spatial memory performance using the Morris water maze test. RESULTS Both phone exposed and control animals showed a significant decrease in escape time with training. Phone exposed animals had significantly (~3 times) higher mean latency to reach the target quadrant and spent significantly (~2 times) less time in the target quadrant than age- and sex-matched controls. CONCLUSION Mobile phone exposure affected the acquisition of learned responses in Wistar rats. This in turn points to the poor spatial navigation and the object place configurations of the phone-exposed animals. PMID:19330250

Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Potu, Bhagath Kumar; Nayak, Satheesha; Mailankot, Maneesh

2009-01-01

241

A pill to treat people exposed to radioactive materials  

SciTech Connect

Berkeley Lab's Rebecca Abergel discusses "A pill to treat people exposed to radioactive materials" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas. Go here to watch the entire event with all 8 speakers:

Abergel, Rebecca

2013-10-31

242

24. VIEW OF NORTHWEST WALL IN ROOM 209, RESTROOM. EXPOSED ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

24. VIEW OF NORTHWEST WALL IN ROOM 209, RESTROOM. EXPOSED BEAM RUNS ALONG NORTHWEST WALL. 3X3 LITE WINDOW IS IN THE NORTHEAST WALL. FLOOR TREATMENT IS WOOD, WALLS ARE GYPSUM BOARD. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

243

Cardiovascular response of rats exposed to 60-Hz electric fields  

SciTech Connect

Recently, it has been reported that exposure to high-strength electric fields can influence electrocardiogram (ECG) patterns, heart rates, and blood pressures in various species of animals. Our studies were designed to evaluate these reported effects and to help clarify some of the disagreement present in the literature. Various cardiovascular variables were measured in Sprague-Dawley rats exposed or sham-exposed to 60-Hz electric fields at 80 to 100 kV/m for periods up to four months. No significant differences in heart rates, ECG patterns, blood pressures, or vascular reactivity were observed between exposed and sham-exposed rats after 8 hours, 40 hours, 1 month, or 4 months of exposure. Our studies cannot be directly compared to the work of other investigators because of differences in animal species and electric-field characteristics. However, our failure to detect any cardiovascular changes may have been the result of (1) eliminating secondary field effects such as shocks, audible noise, corona, and ozone; (2) minimizing steady-state microcurrents between the mouth of the animal and watering devices; and (3) minimizing electric-field-induced vibration of the electrodes and animal cages.

Hilton, D.I.; Phillips, R.D.

1980-01-01

244

Parenting Stress and Child Maltreatment in Drug-Exposed Children.  

ERIC Educational Resources Information Center

This study, with 48 infants and toddlers (24 of which were drug exposed), found that mothers who used drugs during pregnancy reported higher levels of total parenting stress, child-related stress, and parent-related stress than foster mothers and comparison mothers. A strong association between maternal use of drugs and serious child maltreatment…

Kelley, Susan J.

1992-01-01

245

LINER MATERIALS EXPOSED TO TOXIC AND HAZARDOUS WASTES  

EPA Science Inventory

This exploratory experimental research project was conducted (1975-1983) to assess the relative effectiveness and durability of a wide variety of liner materials when exposed to hazardous wastes under conditions that simulate different aspects of service in on-land waste storage ...

246

Gibraltar: Exposing Hardware Devices to Web Pages Using AJAX  

Microsoft Academic Search

Gibraltar is a new framework for exposing hardware devices to web pages. Gibraltar's fundamental insight is that JavaScript's AJAX facility can be used as a hardware access protocol. Instead of relying on the browser to mediate device interactions, Gibraltar sandboxes the browser and uses a small device server to handle hardware requests. The server uses native code to interact with

Kaisen Lin; David Chu; James Mickens; Li Zhuang; Feng Zhao; Jian Qiu

2012-01-01

247

INTRODUCTION Coastal ecosystems have been exposed to serious pollution for  

E-print Network

4010 INTRODUCTION Coastal ecosystems have been exposed to serious pollution for several decades because of increased human activity. Modern agriculture is a major contributor to coastal pollution levels of pollution and potentially harming marine organisms (Banerjee et al., 1996). Some organisms

Alvarez, Nadir

248

26. ROOM 210, VIEW TO THE SOUTHEAST. EXPOSED TIE BEAMS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

26. ROOM 210, VIEW TO THE SOUTHEAST. EXPOSED TIE BEAMS AT CEILING ARE BOXED IN PLYWOOD. WAINSCOTING IS PLYWOOD PANELING. CEILING AND UPPER WALL TREATMENT IS GYPSUM BOARD. CLERESTORY WINDOWS LINE BOTH LONG SIDES OF ROOM. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

249

A multicentre mortality study of workers exposed to ethylene oxide.  

PubMed

A multicentre cohort study was carried out to study the possible association between exposure to ethylene oxide and cancer mortality. The cohort consisted of 2658 men from eight chemical plants of six chemical companies in the Federal Republic of Germany who had been exposed to ethylene oxide for at least one year between 1928 and 1981. The number of subjects in the separate plants varied from 98 to 604. By the closing date of the study (31 December 1982) 268 had died, 68 from malignant neoplasms. For 63 employees who had left the plant (2.4%) the vital status remained unknown. The standardised mortality ratio for all causes of death was 0.87 and for all malignancies 0.97 compared with national rates. When local state rates were used the SMRs were slightly lower. Two deaths from leukaemia were observed compared with 2.35 expected (SMR = 0.85). SMRs for carcinoma of the oesophagus (2.0) and carcinoma of the stomach (1.38) were raised but not significantly. In one plant an internal "control group" was selected matched for age, sex, and date of entry into the factory and compared with the exposed group. In both groups a "healthy worker effect" was observed. The total mortality and mortality from malignant neoplasms was higher in the exposed than in the control group; the differences were not statistically significant. There were no deaths from leukaemia in the exposed group and one in the control group. PMID:2183875

Kiesselbach, N; Ulm, K; Lange, H J; Korallus, U

1990-03-01

250

Hematotoxicity in Workers Exposed to Low Levels of Benzene  

Microsoft Academic Search

Benzene is known to have toxic effects on the blood and bone marrow, but its impact at levels below the U.S. occupational standard of 1 part per million (ppm) remains uncertain. In a study of 250 workers exposed to benzene, white blood cell and platelet counts were significantly lower than in 140 controls, even for exposure below 1 ppm in

Qing Lan; Luoping Zhang; Guilan Li; Roel Vermeulen; Rona S. Weinberg; Mustafa Dosemeci; Stephen M. Rappaport; Min Shen; Blanche P. Alter; Yongji Wu; William Kopp; Suramya Waidyanatha; Charles Rabkin; Weihong Guo; Stephen Chanock; Richard B. Hayes; Martha Linet; Sungkyoon Kim; Songnian Yin; Nathaniel Rothman; Martyn T. Smith

2004-01-01

251

Proteomic analysis of plasma proteins of workers exposed to benzene  

Microsoft Academic Search

In this study, we analyzed the proteins in plasma of workers exposed to benzene by two-dimensional gel electrophoresis, in the hope of finding a specific protein suitable for the biomonitoring of benzene exposure. Comet assays were also carried out to evaluate lymphocytes DNA damage. Fifty workers from a printing company and 38 matched unexposed healthy subjects were enrolled in the

Won-A Joo; Donggeun Sul; Do-Youn Lee; Eunil Lee; Chan-Wha Kim

2004-01-01

252

Expressive language development of children exposed to cocaine prenatally  

Microsoft Academic Search

It was hypothesized that prenatal exposure to cocaine and other substances would be related to delayed expressive language development. Speech and language data were available for 458 6-year olds (204 were exposed to cocaine). No significant univariate or multivariate differences by cocaine exposure group were observed. Classification and regression tree modeling was then used to identify language variable composites predictive

Virginia Delaney-Black; Chandice Covington; Thomas Templin; Trace Kershaw; Beth Nordstrom-Klee; Joel Ager; Nikilia Clark; Arvind Surendran; Susan Martier; Robert J Sokol

2000-01-01

253

Urologic cancer risks for veterans exposed to Agent Orange.  

PubMed

Agent Orange, an herbicide widely used during the Vietnam War, has been linked to various health risks, including urologic malignancy. Exposed veterans are at risk for prostate cancer and may be entitled to compensation if diagnosed with prostate cancer. Current research studies are aimed at mitigating prostate dysplasia and prostate cancer PMID:23734554

Hoenemeyer, Lori A

2013-01-01

254

Semen study of papaya workers exposed to ethylene dibromide  

SciTech Connect

A cross sectional semen and cytogenetic study was performed on male workers exposed to ethylene-dibromide (EDB) in the papaya fumigation industry in Hawaii. Semen analyses were conducted on 46 men in six fumigation facilities with an average length of employment of 5 years and airborne exposures to EDB ranging from 16 to 213 parts per billion. Statistically significant decreases in sperm count per ejaculate and the percentage of viable and motile sperm and increases in the proportion of specific morphological abnormalities were observed among exposed men when compared with controls. Semen volume and sperm concentration were also lower in the exposed group. No effect of exposure to EDB on sperm velocity, the overall proportion of sperm with normal morphology or YFF bodies was noted. The authors conclude that based on the decreases in sperm count, viability and motility and increases in certain types of morphological abnormalities among workers exposed to EDB, EDB may increase the risk of reproductive impairment in workers at exposure levels near the NIOSH recommended limit of 45 parts per billion and far below the current OSHA standard of 20 parts per million.

Ratcliffe, J.M.; Schrader, S.M.; Steenland, K.; Clapp, D.; Turner, T.

1984-01-01

255

Charging time for dust grain on surface exposed to plasma  

SciTech Connect

We consider the charging of a dust grain sitting on a surface exposed to plasma. The stochastic model of Sheridan and Hayes [Appl. Phys. Lett. 98, 091501 (2011)] is solved analytically for the charging time, which is found to be directly proportional to the square root of the electron temperature and inversely proportional to both the grain radius and plasma density.

Sheridan, T. E. [Department of Physics and Astronomy, Ohio Northern University, Ada, Ohio 45810 (United States)

2013-04-14

256

Metrics will expose trusts with poor racial equality feedback.  

PubMed

Trusts that fail to take action on race discrimination will be exposed by a set of metrics expected to be introduced next year, England's chief nursing officer told her black and minority ethnic (BME) advisory group's annual conference last week. PMID:25315534

2014-10-15

257

12. A LONG RUN OF EXPOSED TOP SURFACE, NORTH TRAINING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. A LONG RUN OF EXPOSED TOP SURFACE, NORTH TRAINING WALL, ABOUT 1,500 FEET EAST OF THE FEDERAL CHANNEL MOUTH. VIEW TO WEST, TOWARD SAN FRANCISCO. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

258

Studies of workers exposed to low doses of external radiation  

SciTech Connect

Currently, several epidemiologic studies of workers who have been exposed occupationally to low levels of radiation are being conducted. They include studies of workers in the United States, Great Britain, and Canada involved in the production of both defense materials and nuclear power. This paper focuses on studies evaluating the possible adverse effects that result from external exposure to radiation.37 references.

Gilbert, E.S. (Pacific Northwest Laboratory, Richland, WA (Unites States))

1991-10-01

259

VIEW OF STATION LEARY FACING NORTH SHOWING EXPOSED EXTERIOR FRONT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF STATION LEARY FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT INCLUDING POST 1920 DOORWAY ALTERATIONS, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES - White's Point Reservation, Base End Stations, B"3, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

260

2. VIEW OF STATION FARLEY FACING NORTH SHOWING EXPOSED EXTERIOR ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VIEW OF STATION FARLEY FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES. - White's Point Reservation, Base End Stations, B"6, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

261

VIEW OF STATION SAXTON FACING NORTH SHOWING EXPOSED EXTERIOR FRONT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF STATION SAXTON FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES - White's Point Reservation, Base End Stations, B"2, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

262

VIEW OF STATION LEARY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF STATION LEARY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT AND LEFT SIDE OF THE CONCRETE CONCEALMENT, SANDSTONE FLANKWALL IS VISIBLE AT LEFT REAR - White's Point Reservation, Base End Stations, B"3, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

263

VIEW OF STATION OSGOOD FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF STATION OSGOOD FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT AND LEFT SIDE OF THE CONCRETE CONCEALMENT, SANDSTONE FLANKWALL IS VISIBLE AT LEFT REAR - White's Point Reservation, Base End Stations, B"5, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

264

VIEW OF STATION OSGOOD FACING NORTH SHOWING EXPOSED EXTERIOR FRONT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF STATION OSGOOD FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT INCLUDING POST 1920 DOORWAY ALTERATIONS, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES - White's Point Reservation, Base End Stations, B"5, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

265

3. VIEW OF STATION PARLEY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. VIEW OF STATION PARLEY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT AND LEFT SIDE OF THE CONCRETE CONCEALMENT, SANDSTONE FLANKWALL IS VISIBLE AT LEFT REAR. - White's Point Reservation, Base End Stations, B"6, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

266

Psychosocial impacts in populations exposed to solid waste facilities  

Microsoft Academic Search

This interdisciplinary study uses a parallel case study design to investigate psychosocial impacts in populations exposed to three solid waste facilities in Southern Ontario. Impacts are examined at three social scales: individual, social network and community levels. The objectives and design derive from a feasibility study recently completed by the same research team. A two stage approach is adopted. The

S. Martin Taylor; Susan Elliott; John Eyles; John Frank; Murray Haight; David Streiner; Stephen Walter; Norman White; Dennis Willms

1991-01-01

267

REPRODUCTIVE DEVELOPMENT IN MALE DEER MICE EXPOSED TO AGGRESSIVE BEHAVIOR  

EPA Science Inventory

Male deer mice (Peromyscus maniculatus bairdii) were reared in a long photoperiod and housed individually from 3 weeks of age until they were killed 2, 4, or 6 weeks later. Males that were exposed to aggressive females for 2 min, three times per week, were of normal body weight a...

268

Health Effects of Depleted Uranium on Exposed Gulf War Veterans  

Microsoft Academic Search

A small group of Gulf War veterans possess retained fragments of depleted uranium (DU) shrapnel, the long-term health consequences of which are undetermined. We evaluated the clinical health effects of DU exposure in Gulf War veterans compared with nonexposed Gulf War veterans. History and follow-up medical examination were performed on 29 exposed veterans and 38 nonexposed veterans. Outcome measures employed

Melissa A. McDiarmid; James P. Keogh; Frank J. Hooper; Kathleen McPhaul; Katherine Squibb; Robert Kane; Raymond DiPino; Michael Kabat; Bruce Kaup; Larry Anderson; Dennis Hoover; Lawrence Brown; Matthew Hamilton; David Jacobson-Kram; Belton Burrows; Mark Walsh

2000-01-01

269

CHEMICAL CONTAMINANTS IN NONOCCUPATIONALLY EXPOSED U.S. RESIDENTS  

EPA Science Inventory

The report reviews the manner in which chemical contaminants found in nonoccupationally exposed U.S. residents enter the environment and subsequently human tissue. Approximately 100 contaminants are treated. Sources of literature used in the survey covered a 30-year period, the b...

270

29. VIEW WEST TOWARDS KALAWAO OF PIPELINE, EXPOSED AT LOWER ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

29. VIEW WEST TOWARDS KALAWAO OF PIPELINE, EXPOSED AT LOWER LEFT. CAT TRACKS, MADE BY THE CONSTRUCTION/MAINTENANCE VEHICLES, CAN BE SEEN ALONG BOULDER BEACH - Kalaupapa Water Supply System, Waikolu Valley to Kalaupapa Settlement, Island of Molokai, Kalaupapa, Kalawao County, HI

271

Jetsam: Exposing our Everyday Discarded Objects Eric Paulos Tom Jenkins  

E-print Network

of the movement, activities and familiar patterns of people within and across our urban landscapes. There is also trashcan called Jetsam (Figures 1 and 2). The augmented rubbish bin exposes city dwellers to the pattern trashcans. A sensitive electronic scale determi

Paulos, Eric

272

Behavioural evaluation of workers exposed to mixtures of organic solvents.  

PubMed Central

Reports from Scandinavia have suggested behavioural impairment among long term workers exposed to solvents below regulatory standards. A cross sectional study of behavioural performance was conducted among printers and spray painters exposed to mixtures of organic solvents to replicate the Scandinavian studies and to examine dose-response relationships. Eligible subjects consisted of 640 hourly workers from four midwestern United States companies. Of these, 269 responded to requests to participate and 240 were selected for study based on restrictions for age, sex, education, and other potentially confounding variables. The subjects tested had been employed on average for six years. Each subject completed an occupational history, underwent a medical examination, and completed a battery of behavioural tests. These included the Fitts law psychomotor task, the Stroop colour-word test, the Sternberg short term memory scanning test, the short term memory span test, and the continuous recognition memory test. Solvent exposure for each subject was defined as an exposed or non-exposed category based on a plant industrial hygiene walk-through and the concentration of solvents based on an analysis of full shift personal air samples by gas chromatography. The first definition was used to maintain consistency with Scandinavian studies, but the second was considered to be more accurate. The average full shift solvent concentration was 302 ppm for the printing plant workers and 6-13 ppm for the workers at other plants. Isopropanol and hexane were the major components, compared with toluene in Scandinavian studies. Performance on behavioural tests was analysed using multiple linear regression with solvent concentration as an independent variable. Other relevant demographic variables were also considered for inclusion. No significant (p greater than 0.05) relation between solvent concentration and impairment on any of the 10 behavioural variables was observed after controlling for confounding variables. Exposed/non-exposed comparisons showed a significantly poorer digit span among those exposed, but this has not been generally reported in the Scandinavian studies. The medical examination showed no abnormalities of clinical significance. The inability to replicate the findings of the Scandinavian studies could have been due to the shortness of the duration of workers' exposure, the type of solvents in the mixtures, use of different behavioural tests, or to selection factors. PMID:3876109

Maizlish, N A; Langolf, G D; Whitehead, L W; Fine, L J; Albers, J W; Goldberg, J; Smith, P

1985-01-01

273

Chronic renal effects in three studies of men and women occupationally exposed to cadmium  

Microsoft Academic Search

We measured sensitive indicators of renal damage in three different populations occupationally exposed to cadmium, and examined the degree of variation in damage and the relative sensitivity of different types of indicators. The three studies included (1) men exposed in a cadmium recovery plant, (2) men exposed in a nickel\\/cadmium battery plant, and (3) women exposed in the latter plant.

Patricia W. Mueller; Daniel C. Paschal; Richard R. Hammel; Stephen L. Klincewicz; Mary Louise MacNeil; Bud Spierto; Karen K. Steinberg

1992-01-01

274

Temperature tolerance of nitrite-exposed channel catfish  

SciTech Connect

Upper temperature tolerances of channel catfish Ictalurus punctatus were determined with the critical thermal maximum (CTM) method after fish were exposed to various sublethal concentrations of nitrite for 24 hours at 20/sup 0/C. The CTM was inversely related to nitrite concentration; group means ranged from 38.0/sup 0/C for controls to 35.9/sup 0/C for fish exposed to 1.4 mg NO/sub 2//L. As expected from previous studies, percent methemoglobin was correlated with nitrite concentration, and thus was inversely correlated with CTM. These results indicate that nitrite-temperature interactions have the potential of adversely affecting the productivity of high-density channel catfish aquaculture systems, particularly those located in the southern US during summer. 40 references, 1 table.

Watenpaugh, D.E.; Beitinger, T.L.; Huey, D.W.

1985-03-01

275

Skin friction measurement with partially exposed polymer dispersed liquid crystals  

NASA Technical Reports Server (NTRS)

Partially exposed polymer dispersed liquid crystal thin film (10-25 microns) deposited on a flat glass substrate has been used for the first time to measure skin friction. Utilizing the shear-stress-induced director reorientation in the partially exposed liquid-crystal droplets, optical transmission under crossed polarization has been measured as a function of the air flow differential pressure. Direct measurement of the skin friction with a skin friction drag balance, under the same aerodynamic conditions, lets us correlate the skin friction with optical transmission. This provides a unique technique for the direct measurement of skin friction from the transmitted light intensity. The results are in excellent agreement with the model suggested in this paper.

Parmar, D. S.; Holmes, H. K.

1993-01-01

276

Physiological disturbances in Atlantic salmon exposed to crude oil  

SciTech Connect

In Southern Australia, Atlantic salmon (Salmo salar) farming is undertaken in marine areas where extensive oil exploration, exploitation and transport are taking place. Pen-reared juvenile fish are at high risk of oil exposure through frequent small spills or major accidents. When exposed, commercial fisheries have to face million-dollar loses due to potential tainting of their stocks. In this study, juvenile Atlantic salmon were exposed to Bass Strait light crude oil in a fashion simulating an accidental oil spill at sea i.e. exposure to crude oil followed by a deputation period. Temporal trends in enzymatic bioindicators of exposure were investigated through exposure and deputation periods, as well as several biochemical and chemical measurements. The main objective of the study was to relate tainting with easily measured biological indicators of exposure to crude oil. Good correlations between bioindicators of exposure and tainting could assist fish farming industry to decide on the fate of fish stocks affected by oil taint.

Gagnon, M.M.; Holdway, D.A. [RMIT-Univ., Melbourne, Victoria (Australia)

1995-12-31

277

Trace metals in occupationally and nonoccupationally exposed individuals.  

PubMed

An epidemiological survey was conducted in Houston, Texas on five trace metals in policemen, parking garage attendants, women living near freeways and three control groups of subjects. The controls were matched with the exposed groups for covariate information such as age, sex, smoking habits, ethnic background, socioeconomic status, hair color, and education. Each subject was sampled four times for blood, urine, hair, and feces, and these samples were analyzed for lead, cadmium, zinc, manganese, and copper. Lead and cadmium were correlated with airborne exposures but zinc, manganese and copper were not. The second part of this paper deals with a market study of platinum and palladium markets and a design of an epidemiology survey of individuals occupationally and nonoccupationally exposed to these two metals. The market survey shows that although the catalytic muffler will have a major impact on the market, it is predicted that producers can meet these demands. PMID:1157784

Johnson, D E; Tillery, J B; Prevost, R J

1975-04-01

278

Profiles of Reactivity in Cocaine-Exposed Children  

PubMed Central

This study explored the possibility that specific, theoretically consistent profiles of reactivity could be identified in a sample of cocaine-exposed infants and whether these profiles were associated with a range of infant and/or maternal characteristics. Cluster analysis was used to identify distinct groups of infants based on physiological, behavioral and maternal reported measures of reactivity. Five replicable clusters were identified which corresponded to 1) Dysregulated/High Maternal Report Reactors, 2) Low Behavioral Reactors, 3) High Reactors, 4) Optimal Reactors and 5) Dysregulated/Low Maternal Report Reactors. These clusters were associated with differences in prenatal cocaine exposure status, birthweight, maternal depressive symptoms, and maternal negative affect during mother-infant interactions. These results support the presence of distinct reactivity profiles among high risk infants recruited on the basis of prenatal cocaine exposure and demographically similar control group infants not exposed to cocaine. PMID:23204615

Schuetze, Pamela; Molnar, Danielle S.; Eiden, Rina D.

2012-01-01

279

Radiation effects on ETFE polymer exposed to glow discharge  

NASA Astrophysics Data System (ADS)

The polymer ethylenetetrafluoroethylene (ETFE) is composed of alternating ethylene and tetrafluoroethylene segments. Because it has applications in areas such as medical physics and industrial coatings, there is a great interest in surface modification studies of ETFE polymer. When this material is exposed to ionizing radiation it suffers damage that depends on the type, energy and intensity of the irradiation. In order to determine the radiation damage mechanism from exposure to low voltage plasma, ETFE films were exposed to residual gas plasma in glow discharge regime to a fluence of 2 × 10 17 ions/cm 2. Irradiated films were analyzed with optical absorption photospectrometry, Fourier transform infrared (FTIR) and Raman spectroscopy to determine the chemical nature of the structural changes caused by low energy glow discharge.

Minamisawa, Renato Amaral; Abidzina, Volha; de Almeida, Adelaide; Budak, Satilmis; Tereshko, I.; Elkin, I.; Ila, Daryush

2007-08-01

280

Temperature increase in the fetus exposed to UHF RFID readers.  

PubMed

Exposure to electromagnetic fields (EMFs) has prominently increased during the last decades due to the rapid development of new technologies. Among the various devices emitting EMFs, those based on Radio-frequency identification (RFID) technologies are used in all aspects of everyday life, and expose people unselectively. This scenario could pose a potential risk for some groups of the general population, such as pregnant women, who are expected to be possibly more sensitive to the thermal effects produced by EMF exposure. This is the first paper that addresses the estimation of temperature rise in two pregnant women models exposed to ultrahigh frequency RFID by computational techniques. Results show that the maximum temperature increase of the fetus and of the pregnancy-related tissues is relatively high (even about 0.7 °C), not too far from the known threshold of biological effects. However, this increase is confined to a small volume in the tissues. PMID:24956619

Fiocchi, Serena; Parazzini, Marta; Liorni, Ilaria; Samaras, Theodoros; Ravazzani, Paolo

2014-07-01

281

Hydrogen Absorption in Iron Exposed to Simulated Concrete Pore Solutions  

Microsoft Academic Search

Safe cathodic protection (CP) limits are required for prestressed steel in concrete to avoid the risk of hydrogen embrittlement (HE). This preliminary study addressed some effects of concrete pore solution chemistry and metal surface condition on hydrogen absorption in iron. To accomplish this, the Devanathan-Stachurski permeation technique was used to investigate hydrogen absorption in 99.5% iron foils exposed to NaOH,

R. S. Lillard; J. R. Scully

1996-01-01

282

Light Timber-Framed Walls Exposed to Compartment Fires  

Microsoft Academic Search

The objective of this project was to determine the equivalent time of exposure (to the ISO-834 standard fire), for a number of light timber-framed wall assemblies exposed to a range of time temperature curves characteristic of compartment fires.This analysis considered only the thermal behavior of the walls. Load bearing performance will be the subject of the next phase of the

G. C. Thomas; A. H. Buchanan; A. J. Carr; C. M. Fleischmann; P. J. Moss

1995-01-01

283

Tectonostratigraphy of the exposed Silurian deposits in Arabia  

Microsoft Academic Search

Exposed Silurian deposits in Arabia are represented by the Qalibah Group, the Qusaiba and Sharawra formations. The Qusaiba\\u000a Formation is composed of dark-gray claystones and siltstones. It is disconformably underlain by the Late Ordovician–Early\\u000a Silurian? Uqlah Formation or unconformably underlain by the Late Ordovician Zarqa or Sarah formations. It is disconformably\\u000a overlain by the Sharawra Formation. The Early Rhuddanian basal

Abdulaziz A. Al-Laboun

2009-01-01

284

Biochemical responses in gills of rainbow trout exposed to propiconazole  

Microsoft Academic Search

The aim of this study is to investigate the toxic effect of PCZ, a triazole fungicide commonly present in surface and ground\\u000a water, on the ROS defense system and Na+-K+-ATPase in gills of rainbow trout exposed to sublethal concentrations (0.2, 50 and 500 ?g L?1) for 7, 20 and 30 days. After prolonged exposure of PCZ at higher test concentrations

Zhi-Hua Li; Vladimir Zlabek; Roman Grabic; Ping Li; Tomas Randak

2011-01-01

285

Coronary heart disease among workers exposed to carbon disulphide  

Microsoft Academic Search

Hernberg, S., Partanen, T., Nordman, C-H., and Sumari, P. (1970).Brit. J. indust. Med.,27, 313-325. Coronary heart disease among workers exposed to carbon disulphide. Coronary morbidity and some coronary risk factors were studied among workers in a viscose rayon plant. All men with at least five years' exposure to carbon disulphide during any period between 1942 and 1967 were included. In

S. Hernberg; T. Partanen; C. H. Nordman; P. Sumari

1970-01-01

286

Biological monitoring of a worker acutely exposed to MBOCA  

Microsoft Academic Search

A 30 year-old male polyurethane worker was exposed to an accidental spill of 4,4'-methylene-bis-2-chloroaniline (MBOCA) at a plant producing MBOCA-cured plastic products. Exposure to MBOCA is significant in that this compound is a known animal carcinogen and a suspected human carcinogen. The employee was sprayed over his upper body and extremities with molten MBOCA while cleaning out a clogged hose

Ana Maria Osorio; David Clapp; Elizabeth Ward; H. Kerr Wilson; John Cocker

1990-01-01

287

Shorebird use of an exposed sandy beach in southern California  

Microsoft Academic Search

Frequent morning surveys of birds were conducted on 1 km of beach in southern California to investigate shorebird use of an exposed sandy beach. The overall mean abundance (98.6individualskm?1), estimated biomass (9.6kgkm?1), and species richness (5.5specieskm?1) of shorebirds observed were very high for a sandy beach in the temperate zone. Eight species, sanderling (Calidris alba), semipalmated plover (Charadrius semipalmatus), marbled

David M. Hubbard; Jenifer E. Dugan

2003-01-01

288

Vaporization of Bicomponent Droplets Exposed to Asymmetric Radiant Heating  

Microsoft Academic Search

In this work, the fuel vapor distribution around vaporizing bicomponent droplets, exposed to asymmetric radiant heating, is investigated as an extension of prior work done by the authors involving single-component droplets. Acetone\\/octane and acetone\\/hexane mixtures (50\\/50 by volume) are used to explore bicomponent droplet phenomena within the context of asymmetric radiant heating. Planar laser-induced fluorescence images yield acetone vapor molar

K. Ammigan; R. S. Miller; H. L. Clack

2011-01-01

289

Distributed Fluorescence Sensing Using Exposed Core Microstructured Optical Fiber  

Microsoft Academic Search

Fluorescence-based distributed sensing using exposed core microstructured optical fiber has been demonstrated. The optical fiber consists of a suspended optical micro-wire surrounded by a solid jacket, a portion of which is absent to allow access to the evanescent field from the external environment. We demonstrate time-domain distributed sensing by immersing different sections of the fiber in a fluorescent liquid.

Stephen Christopher Warren-Smith; Elena Sinchenko; Paul R. Stoddart; Tanya M. Monro

2010-01-01

290

Occupational hypersensitivity pneumonitis in a smelter exposed to zinc fumes  

SciTech Connect

A smelter exposed to zinc fumes reported severe recurrent episodes of cough, dyspnea and fever. Bronchoalveolar lavage showed a marked increase in lymphocytes count with predominance of CD8 T-lymphocytes. Presence of zinc in alveolar macrophages was assessed by analytic transmission electron microscopy. This is the first case of recurrent bronchoalveolitis related to zinc exposure in which the clinical picture and BAL results indicate a probable hypersensitivity pneumonitis.

Ameille, J.; Brechot, J.M.; Brochard, P.; Capron, F.; Dore, M.F. (Consultation de Pathologie Professionnelle, Hopital Raymond Poincare, Garches, (France))

1992-03-01

291

Potential contribution of exposed resin to ecosystem emissions of monoterpenes  

NASA Astrophysics Data System (ADS)

Conifers, especially pines, produce and store under pressure monoterpene-laden resin in canals located throughout the plant. When the plants are damaged and resin canals punctured, the resin is exuded and the monoterpenes are released into the atmosphere, a process that has been shown to influence ecosystem-level monoterpene emissions. Less attention has been paid to the small amounts of resin that are exuded from branches, expanding needles, developing pollen cones, and terminal buds in the absence of any damage. The goal of this study was to provide the first estimate of the potential of this naturally-exposed resin to influence emissions of monoterpenes from ponderosa pine (Pinus ponderosa) ecosystems. When resin is first exuded as small spherical beads from undamaged tissues it emits monoterpenes to the atmosphere at a rate that is four orders of magnitude greater than needle tissue with an equivalent exposed surface area and the emissions from exuded beads decline exponentially as the resin dries. We made measurements of resin beads on the branches of ponderosa pine trees in the middle of the growing season and found, on average, 0.15 cm2 of exposed resin bead surface area and 1250 cm2 of total needle surface area per branch tip. If the resin emerged over the course of 10 days, resin emissions would make up 10% of the ecosystem emissions each day. Since we only accounted for exposed resin at a single point in time, this is probably an underestimate of how much total resin is exuded from undamaged pine tissues over the course of a growing season. Our observations, however, reveal the importance of this previously unrecognized source of monoterpenes emitted from pine forests and its potential to influence regional atmospheric chemistry dynamics.

Eller, Allyson S. D.; Harley, Peter; Monson, Russell K.

2013-10-01

292

Mechanical properties of foamed concrete exposed to high temperatures  

Microsoft Academic Search

This paper reports the results of an experimental and analytical study to investigate the mechanical properties of unstressed foamed concrete exposed to high temperatures. Two densities of foamed concrete, 650 and 1000 kg\\/m 3, were made and tested with additional tests being performed on densities of 800, 1200 and 1400 kg\\/m3 for additional data. The experimental results consistently demonstrated that

M. A. O. Mydin; Yong Wang

2012-01-01

293

Reproduction success of American kestrels exposed to dietary polychlorinated biphenyls.  

PubMed

While reproduction of wild birds is adversely affected by multiple environmental contaminants, we determined that polychlorinated biphenyls (PCBs) alone alter reproduction. Captive American kestrels (Falco sparverius), fed PCB-spiked (Aroclor 1248:1254:1260) food (7 mg/kg body weight/d) prior to and during the first breeding season only (100 d) laid eggs with environmentally relevant levels of total PCBs (34.0 microg/g whole egg wet wt vs 0 microg/g for controls). Reproduction changed during, not after, PCB exposure in this two-year study. The PCB-exposed pairs laid smaller clutches later in the season and laid more totally infertile clutches. Hatching success was reduced in PCB-exposed pairs, and 50% of PCB nestlings died within 3 d of hatching. Nearly 60% of PCB-exposed pairs with hatchlings failed to produce fledglings. Higher levels of total PCB residues and congeners were associated with later clutch initiation and fewer fertile eggs, hatchlings, and fledglings. We suggest that nonpersistent PCB congeners have a greater influence on reproduction than do persistent congeners. PMID:11345453

Fernie, K J; Smits, J E; Bortolotti, G R; Bird, D M

2001-04-01

294

Recovery of chlorine-exposed Escherichia coli in estuarine microcosms.  

PubMed

Laboratory microcosm experiments were performed to determine whether chlorine-exposed Escherichia coli are capable of recovery (i.e., increase in numbers of culturable cells) in estuarine waters and if so what water-quality parameters are responsible for this recovery. Suspensions of E. coli were exposed to 0.5 mg L(-1) of chlorine for 5 min followed by dechlorination with sodium thiosulfate. The chlorine-exposed bacteria were introduced into 2-L microcosms containing estuarine water collected from the Seacoast region of New Hampshire. Culturable cells in the microcosms were enumerated at 0, 10, 24, 48, and 74 h. In all estuarine microcosms the number of culturable cells increased by factors ranging from 2.8 to 50 over the 74-h incubation period. Multiple linear regression analyses indicated that ammonium and salinity were most significantly correlated with the recovery of E. coli over the 74-h incubation period; however, ammonium concentrations were strongly correlated with dissolved organic carbon and total dissolved nitrogen, making it impossible to determine with any degree of certainty the unique effect nitrogen or carbon had on recovery. The extensive recovery observed in our study indicates that following exposure to concentrations of chlorine that cause cell injury rather than death, numbers of culturable E. coli may increase significantly when discharged into estuarine waters. Thus, depending on the effectiveness of the chlorination process, the regular monitoring of chlorinated wastewater treatment effluent may underestimate the true impact on water-quality and public health risks. PMID:15926556

Bolster, Carl H; Bromley, Jonathan M; Jones, Stephen H

2005-05-01

295

A Neuropsychological Study of Patients Exposed to Organic Solvents.  

PubMed

Sixty-seven male patients exposed to organic solvents were neurospychologically examined. Twenty-five subjects had possible causes of encephalopathy other than solvent exposure, leaving 42 patients for the study of the association between exposure and neuropsychological test results. The patients had been heavily exposed for, on average, 24.6 years (range 2-46). The main clinical findings were impairments of psychomotor function, short-term memory, and attention. The results suggest an association between impaired psychomotor speed and exposure duration (r = 0.41; p = 0.007), with moderate to severe impairment occurring after at least 15 years. Forty percent of the patients exposed for more than 30 years had moderate to severely impaired psychomotor speed. The results suggest declining test performance on Trail Making Test B related to exposure duration (r = -0.34; p = 0.03). Further, the individual age-adjusted score on the Digit Span task (WAIS) was reduced when compared with the individual age-adjusted score on the Picture Completion task (WAIS). This reduction was related to exposure duration (r = -0.48; p = 0.002). PMID:9891116

Ellingsen; Lorentzen; Langård

1997-07-01

296

Genetic damage in subjects exposed to radiofrequency radiation.  

PubMed

Despite many research efforts and public debate there is still great concern about the possible adverse effects of radiofrequency (RF) radiation on human health. This is especially due to the enormous increase of wireless mobile telephones and other telecommunication devices throughout the world. The possible genetic effects of mobile phone radiation and other sources of radiofrequencies constitute one of the major points of concern. In the past several review papers were published on laboratory investigations that were devoted to in vitro and in vivo animal (cyto)genetic studies. However, it may be assumed that some of the most important observations are those obtained from studies with individuals that were exposed to relatively high levels of radiofrequency radiation, either as a result of their occupational activity or as frequent users of radiofrequency emitting tools. In this paper the cytogenetic biomonitoring studies of RF-exposed humans are reviewed. A majority of these studies do show that RF-exposed individuals have increased frequencies of genetic damage (e.g., chromosomal aberrations) in their lymphocytes or exfoliated buccal cells. However, most of the studies, if not all, have a number of shortcomings that actually prevents any firm conclusion. Radiation dosimetry was lacking in all papers, but some of the investigations were flawed by much more severe imperfections. Large well-coordinated multidisciplinary investigations are needed in order to reach any robust conclusion. PMID:19073278

Verschaeve, Luc

2009-01-01

297

Increased gluconeogenesis in rats exposed to hyper-G stress  

NASA Technical Reports Server (NTRS)

The effect of glucogenesis on the plasma glucose and liver glycogen of rats exposed to hyper-G stress is investigated. Twelve male Sprague-Dawley rats are injected with C-14 lactate, alanine, of glycerol, and six of the rats are exposed to 3.1 G for 0.25, 0.50, and 1.0 hr. The plasma glucose and liver glycogen of the centrifuged and noncentrifuged rats are analyzed. A significant increase in the C-14 incorporation of the substrate into the plasma glucose and liver glycogen is observed in the centrifuged rats. The injection of 5-methoxyindole-2-carboxylic acid, a gluconeogenesis inhibitor, results in a blocked increase in plasma glucose and liver glycogen. The role of epinephrine on the hyperglycemic and liver glycogen responses of centrifuged rats is studied. It is concluded that the initial increase in plasma glucose and liver glycogen in rats exposed to hyper-G stress is the result of an increased rate of gluconeogenesis.

Daligcon, B. C.; Oyama, J.; Hannak, K.

1985-01-01

298

Fate of graphene in polymer nanocomposite exposed to UV radiation  

NASA Astrophysics Data System (ADS)

Graphene is increasingly incorporated in polymers to enhance their mechanical, thermal and electrical properties. However, organic polymers are prone to degrade when exposed to UV radiation. Therefore, graphene in polymer nanocomposites could eventually be released into the environment during their life cycle, which might have a negative impact on the environment and thus presents a roadblock to their use. This study investigates the degradation of a graphene/polyurethane composite and characterizes the graphene concentration at the nanocomposite surfaces during exposure to UV radiation. The polyurethane was a one-component, water-borne polyurethane and graphene material was graphene oxide (GO) sheets. GO/WBPU composites having a thickness between 105 ?m and 150 ?m were exposed to 75% RH, 50°C, and UV radiation between 290 nm and 400 nm in a NIST-developed UV chamber. Chemical degradation, mass loss, and surface morphology were measured at specified exposure time using FTIR, gravimetry, SEM, AFM and LCSM techniques. Results showed that, when exposed to UV radiation having wavelengths similar to those of the sunlight, the polyurethane matrix underwent photodegradation, subsequent mass loss and accumulation of a large amount of graphene on the composite surface.

Bernard, C.; Nguyen, T.; Pellegrin, B.; Holbrook, R. D.; Zhao, M.; Chin, J.

2011-07-01

299

Analysis Of The Returned Samples From A Space Exposure Experiment: The ORGANIC Experiment on EXPOSE-R on the ISS  

NASA Astrophysics Data System (ADS)

The ORGANIC experiment on the multi-user facility EXPOSE-R on the International Space Station investigated the chemical evolution, survival, destruction, and chemical modification of PAHs and fullerenes in space. Aromatic networks are among the most abundant organic material in space. PAHs and fullerenes have been identified in meteorites and are thought to be among the carriers for numerous astronomical absorption and emission features.Thin films of selected PAHs and fullerenes have been subjected to the low Earth orbit environment as part of the ORGANIC experiment.EXPOSE-R with its experiment inserts was mounted on the outside of the ISS for 682 days starting in 2009. The samples were returned to Earth and inspected in spring 2011. The period outside the ISS provided continuous exposure to the cosmic-, solar-, and trapped-particle radiation background and >2500 h of unshadowed solar illumination. All trays carry both solar-irradiation-exposed and dark samples shielded from the UV photons, enabling discrimination between the effects of exposure to solar photons and cosmic rays. The samples were analyzed before exposure to the space environment with UV-VIS and IR spectroscopy. Ground truth monitoring of additional sample carriers was performed through UV-VIS spectroscopy at regular intervals at NASA ARC (Bryson et al. 2011, Adv. Space Res. 48, 1980). The UV-VIS and IR spectroscopic measurements were collected for the returned flight samples.We report on the scientific experiment, the details of the ground control analysis, and returned flight sample results. We discuss how extended space exposure experiments allow to enhance our knowledge on the evolution of organic compounds in space.

Bryson, Kathryn; Peeters, Zan; Salama, Farid; Foing, Bernard; Ehrenfreund, Pascale; Elsaesser, Andreas; Ricco, Antonio; Jessberger, Elmar K; Schmidt, Werner; Robert, François

2014-06-01

300

Petroleum films exposed to sunlight produce hydroxyl radical.  

PubMed

Sunlight exposed oil films on seawater or pure water produced substantial amounts of hydroxyl radical as a result of irradiation. Oil was collected from the surface of the Gulf of Mexico following the Deepwater Horizon spill and exposed to simulated sunlight in thin films over water. Photochemical production of hydroxyl radical was measured with benzoic acid as a selective chemical probe in the aqueous layer. Total hydroxyl radical formation was studied using high benzoic acid concentrations and varying exposure time. The total amount of hydroxyl radical produced in 24 h irradiations of thin oil films over Gulf of Mexico water and pure water were 3.7×10(-7) and 4.2×10(-7) moles respectively. Steady state concentrations of hydroxyl radical were measured using a competition kinetics approach. Hydroxyl radical concentrations of 1.2×10(-16) to 2.4×10(-16) M were observed for seawater and pure water under oil films. Titanium dioxide (TiO2) nanomaterials were added to the system in an effort to determine if the photocatalyst would enhance oil photodegradation. The addition of TiO2 nanoparticles dramatically changed the observed formation rate of hydroxyl radical in the systems with NP water at pH 3, showing increased formation rate in many cases. With photocatalyst, the steady state concentration of radical decreased, predominantly due to an increase in the hydroxyl radical scavenging rate with oxide present. This study illustrates that oil is a strong and important source of hydroxyl radical when exposed to sunlight. The fate of oil and other dissolved species following oil spills will be heavily dependent on the formation and fate of hydroxyl radical. PMID:24405967

Ray, Phoebe Z; Tarr, Matthew A

2014-05-01

301

Exposed-core chalcogenide microstructured optical fibers for chemical sensing  

NASA Astrophysics Data System (ADS)

Chemical bonds of most of the molecules vibrate at a frequency corresponding to the near or mid infrared field. It is thus of a great interest to develop sensitive and portable devices for the detection of specific chemicals and biomolecules for various applications in health, the environment, national security and so on. Optical fibers define practical sensing tools. Chalcogenide glasses are known for their transparency in the infrared optical range and their ability to be drawn as fibers. They are consequently good candidates to be used in biological/chemical sensing. For that matter, in the past decade, chalcogenide glass fibers have been successfully implemented in evanescent wave spectroscopy experiments, for the detection of bio-chemical species in various fields of applications including microbiology and medicine, water pollution and CO2 detection. Different types of fiber can be used: single index fibers or microstructured fibers. Besides, in recent years a new configuration of microstructured fibers has been developed: microstructured exposed-core fibers. This design consists of an optical fiber with a suspended micron-scale core that is partially exposed to the external environment. This configuration has been chosen to elaborate, using the molding method, a chalcogenide fiber for chemical species detection. The sensitivity of this fiber to detect molecules such as propan-2-ol and acetone has been compared with those of single index fibers. Although evanescent wave absorption is inversely proportional to the fiber diameter, the result shows that an exposed-core fiber is much more sensitive than a single index fiber having a twice smaller external diameter.

Troles, Johann; Toupin, Perrine; Brilland, Laurent; Boussard-Plédel, Catherine; Bureau, Bruno; Cui, Shuo; Mechin, David; Adam, Jean-Luc

2013-05-01

302

Neurobehavioural evaluation of Venezuelan workers exposed to inorganic lead.  

PubMed Central

OBJECTIVES--To assess neurobehavioural effects of low exposure to lead, 43 workers from a lead smelter and 45 workers from a glass factory were evaluated with the World Health Organisation neurobehavioural core test battery (NCTB) in a cross sectional study. METHODS--The NCTB comprises a questionnaire and seven tests that measure simple reaction time, short-term memory (digit span, Benton), mood (profile of mood states), eye-hand coordination (Santa Ana pegboard, pursuit aiming II), and perceptual speed (digit-symbol). RESULTS--Smelter workers were employed on average for four years, and had a mean blood lead concentration of 2.0 mumol/l (42 micrograms/dl). Glass factory workers had a mean of 0.72 mumol/l (15 micrograms/dl). Historical blood lead concentrations were used to classify exposure based on current, peak, and time weighted average. Although the exposed workers performed less well than the non-exposed in 10 of 14 response variables, only profile of mood states tension-anxiety, hostility, and depression mood scales showed a significantly poorer dose-response relation with blood lead concentration in multiple linear regression models that included age, education, and alcohol intake as covariates. The frequency of symptoms of anger, depression, fatigue, and joint pain were also significantly increased in the exposed group. CONCLUSION--This study is consistent with the larger body of neurobehavioural research of low occupational exposure to lead. The small effects found in this study occurred at blood lead concentrations slightly lower than those reported in several previous studies. PMID:7627319

Maizlish, N A; Parra, G; Feo, O

1995-01-01

303

Disease susceptibility of salmon exposed to polybrominated diphenyl ethers (PBDEs).  

PubMed

The health effects of the flame retardant polybrominated diphenyl ethers (PBDEs) in fish are not well understood. To determine the potential effects of this ubiquitous contaminant class on fish health, juvenile subyearling Chinook salmon (Oncorhynchus tshawytscha) were fed a diet that reflected the PBDE congeners found in the stomach contents of subyearling Chinook salmon collected from the highly urbanized and industrialized lower Willamette River in the Columbia River Basin of North America. The diet, consisting of five PBDE congeners (BDE-47, BDE-99, BDE-100, BDE-153 and BDE-154), was fed to the salmon at 2% of their body weight in food per day for 40 days. Two concentrations of the diet (1x and 10x PBDE) were fed to the salmon. The 1x PBDE diet reflected the concentration of PBDEs (190 ng PBDEs/g food) found in the stomach contents of juvenile subyearling Chinook salmon; the 10x diet was prepared at 10 times that concentration. The fish were then exposed to the marine bacterial pathogen Listonella anguillarum to assess susceptibility to infectious disease. Juvenile Chinook salmon fed the 1x PBDE diet were more susceptible to L. anguillarum than salmon fed the control diet. This suggests that juvenile salmonids in the lower Willamette River exposed to PBDEs may be at greater risk for disease than nonexposed juvenile salmonids. In contrast, salmon that consumed the 10x PBDE diet were not more susceptible to the pathogen than salmon fed the control diet. The mechanisms for the dichotomous results observed in disease susceptibility between salmon fed the 1x and 10x PBDE diets are currently not known but have also been observed in other species exposed to PBDEs with respect to immune function. PMID:20207027

Arkoosh, Mary R; Boylen, Deborah; Dietrich, Joseph; Anulacion, Bernadita F; Ginaylitalo; Bravo, Claudia F; Johnson, Lyndal L; Loge, Frank J; Collier, Tracy K

2010-06-01

304

Cultural Heritage exposed to landslide and flood risk in Italy  

NASA Astrophysics Data System (ADS)

Italy is the country that owns most of the world cultural heritage as it's clear from the list of sites of inestimable value to humanity, prepared by UNESCO under the Convention concerning the protection of the world cultural and natural heritage ratified in 1972. The Italian territory is also particularly prone to natural hazards such as landslides, floods, earthquakes, volcanic eruptions, subsidence and coastal erosion which undermine the protection and preservation of cultural heritage. Aim of the present work is to provide an estimate of architectural, monumental and archaeological heritage exposed to landslide and flood risk at national scale. The input data are: the Italian Cultural Heritage database (Carta del Rischio del patrimonio culturale) realized by ISCR (Central Institute for the Conservation and Restoration); the Italian Landslide Inventory (Progetto IFFI) developed by ISPRA (Italian National Institute for Environmental Protection and Research) and the Regions and Self-Governing Provinces of Italy and the flood hazard zones defined by the Italian River Basin Authorities. Italian landslide inventory contains more than 486,000 landslides affecting an area of about 20,800 km2, equal to 6.9% of Italian territory. In order to estimate the number and type of cultural heritage at risk some GIS processing have been carried out, overlapping information from the above mentioned databases. The analysis provided the following results: Cultural Heritage exposed to landslide risk were estimated to 5.511 (6.6%) while the ones exposed to flood risk results 9.859 (11.7%). Two case studies concerning landslide phenomena affecting important Italian municipalities and the flood risk of historical centre of Rome, have been also analyzed. These results could be used to identify priorities and plan field surveys, detailed studies and monitoring systems, allowing job scheduling of cultural heritage maintenance. This need becomes more and more a necessity taking into account the importance of the Italian cultural heritage and the lack of funds available for its protection and conservation.

Spizzichino, Daniele; Cacace, Carlo; Iadanza, Carla; Trigila, Alessandro

2013-04-01

305

Saffron Improves Epididymal Sperm Parameters in Rats Exposed to Cadmium  

PubMed Central

Background: Cadmium (Cd) is known to cause various disorders in the testis. The general population may be exposed to Cd through ingestion of food and drinking water, inhalation of particulates from ambient air, tobacco smoke and ingestion of contaminated soil and dust. Saffron (Crocus sativus L.) is widely used as a food flavour, and has well known medicinal effects. Objectives: The aim of this study was to determine the effects of saffron on the results of semen parameters (sperm concentration, motility and viability in cauda of epididymis) in rats exposed to cadmium. Materials and Methods: Thirty Wistar male rats were divided into four groups. Cadmium chloride (1 mg/kg body weight) was injected intraperitoneally during 16 days at intervals of 48 hours between subsequent treatments. Crocus sativus L. (100 mg/kg b.w., IP) was pretreated in both control and cadmium-injected rats. Both control and cadmium-injected rats were pretreated with Crocus sativus L. (100 mg/kg b.w., IP). The animals were killed and their sperm count, motility, and vitality were evaluated. Results: Sperm parameters did not differ significantly between control and sham groups. Following contamination with cadmium, sperm count, motility and vitality were significantly decreased in comparison to control group (P < 0.05). In pretreated (saffron) group, the sperm parameters improved significantly in comparison with cadmium group (P ? 0.05). A significant decrease in sperm motility was observed in Cd-treated rats compared to the control rats. However, no significant changes were recorded by comparison of the control and saffron treated groups except for the sperm motility parameter. Conclusions: Saffron, as an antioxidant, is positively effective on sperm parameters in rats exposed with cadmium. PMID:24719804

Asadi, Mohammad Hossein; Zafari, Fariba; Sarveazad, Arash; Abbasi, Mehdi; Safa, Majid; Koruji, Morteza; Yari, Abazar; Alizadeh Miran, Rafieh

2013-01-01

306

Photoluminescence from Si nanocrystals exposed to a hydrogen plasma  

NASA Astrophysics Data System (ADS)

Si nanocrystals embedded in SiO2 films were exposed to an atomic H plasma at different temperatures. Photoluminescence intensity from the nanocrystals increases with increasing exposure time, followed by saturation that depends on the exposure temperature. The saturation level depends on the final exposure temperature and shows no dependence on the thermal history of exposure. This behavior is shown to be consistent with a model in which the steady-state passivation level is determined by a balance between defect passivation and depassivation by H, with the activation energy for the passivation reaction being larger than that for the depassivation reaction.

Jung, Yoon-Jin; Yoon, Jong-Hwan; Elliman, R. G.; Wilkinson, A. R.

2008-10-01

307

Cytogenetic biomonitoring of the Mzamza population exposed to untreated wastewaters.  

PubMed

A cytogenetic biomonitoring study was performed on people from the Mzamza community near Settat, Morocco. These subjects live in and near the Bou Moussa valley where wastewaters from a great number of industries are discharged without any treatment. This wastewater is used as a source of drinking water for their cattle and irrigation of their land. The Mzamza population is therefore presumably exposed to continuous low doses of different kinds of pollutants. Our study demonstrated significant increases in micronucleated white blood cells indicating a considerable genetic risk in these subjects. PMID:17639334

Glouib, K; Hilali, A; Kettani, S El; Verschaeve, L

2007-08-01

308

Susuk - Black Magic Exposed "White" by Dental Radiographs  

PubMed Central

Susuk or charm needles are a facial cum body art widely practiced among women of Malaysia, Brunei, Singapore, Thailand and Indonesia. These are small, needle-shaped metallic talismans inserted subcutaneously in different parts of the body. The concealed art of susuk was “exposed” by routine radiographic examination in the oral and maxillofacial region. This paper reports two such cases of unusual incidental radiographic finding in dental radiographs which were taken on a routine basis as part of the diagnostic work up. This article will also primarily enlighten the importance of radiographs in detecting such charm needles as the wearer keeps the body art a “hidden secret” thereby avoiding misdiagnosis. PMID:25177646

Mohammed, Faraz

2014-01-01

309

Erosion of graphite surface exposed to hot supersonic hydrogen gas  

NASA Technical Reports Server (NTRS)

A theoretical model based on laminar boundary layer flow equations is developed to predict the erosion rate of a graphite (AGCarb-101) surface exposed to a hot supersonic stream of hydrogen gas. The supersonic flow in the nozzle outside the boundary layer formed over the surface of the specimen is determined by assuming one-dimensional isentropic conditions. An overall surface reaction rate expression based on the experimental studies by Clarke and Fox is used to describe the interaction of hydrogen with graphite. A satisfactory agreement is found between the results of the computation, and the available experimental data. Some shortcomings of the model, and further possible improvements are discussed.

Sharma, O. P.

1972-01-01

310

Effective UV radiation dose in polyethylene exposed to weather  

NASA Astrophysics Data System (ADS)

In this work we quantified the effective UV radiation dose in orange and colorless polyethylene samples exposed to weather in the city of Aguascalientes, Ags. Mexico. The spectral distribution of solar radiation was calculated using SMART 2.9.5.; the samples absorption properties were measured using UV-Vis spectroscopy and the quantum yield was calculated using samples reflectance properties. The determining factor in the effective UV dose is the spectral distribution of solar radiation, although the chemical structure of materials is also important.

González-Mota, R.; Soto-Bernal, J. J.; Rosales-Candelas, I.; Calero Marín, S. P.; Vega-Durán, J. T.; Moreno-Virgen, R.

2009-09-01

311

Spectrum of alveolitis in quartz-exposed human subjects  

SciTech Connect

To characterize silica-induced alveolitis in human subjects, we studied 22 workers in the granite stone cutting industry of Quebec and compared results with those of 22 manual workers without quartz exposure (group 1). All were nonsmokers and were of comparable age. On the basis of chest roentgenogram, seven were without disease (group 2), nine had silicosis without coalescence/conglomeration (group 3), and six had silicosis with coalescence/conglomeration (group 4). The alveolitis in subsets of silica-exposed workers with distinct clinical stages of disease was found to have distinct biologic characteristics.

Begin, R.O.; Cantin, A.M.; Boileau, R.D.; Bisson, G.Y.

1987-12-01

312

Spectrum of alveolitis in quartz-exposed human subjects.  

PubMed

To characterize silica-induced alveolitis in human subjects, we studied 22 workers in the granite stone cutting industry of Quebec and compared results with those of 22 manual workers without quartz exposure (group 1). All were nonsmokers and were of comparable age. On the basis of chest roentgenogram, seven were without disease (group 2), nine had silicosis without coalescence/conglomeration (group 3), and six had silicosis with coalescence/conglomeration (group 4). The alveolitis in subsets of silica-exposed workers with distinct clinical stages of disease was found to have distinct biologic characteristics. PMID:2824136

Bégin, R O; Cantin, A M; Boileau, R D; Bisson, G Y

1987-12-01

313

Prevalence of metabolic syndrome in Chinese nickel-exposed workers.  

PubMed

The prevalence of metabolic syndrome (MS) was investigated in Chinese nickel-exposed workers. A total of 35 104 subjects were enrolled in this study. The age-adjusted prevalence of MS, BMI?25, diabetes, hypertension, and abnormal lipid was 13.9%, 29.5%, 12.8%, 27.5%, and 47.1%, respectively. The prevalence of BMI?25, hyperglycemia, and hypertension increased with the age of males and females, and was higher in males than in females (37.1% vs 21.5%, 15.9% vs 12.1%, 35.0% vs 24.3%, 54.3% vs 40.4%). PMID:24961859

Yang, Ai Min; Bai, Ya Na; Pu, Hong Quan; Zheng, Tong Zhang; Cheng, Ning; Li, Juan Sheng; Li, Hai Yan; Zhang, Ya Wei; Ding, Jiao; Su, Hui; Ren, Xiao Wei; Hu, Xiao Bin

2014-06-01

314

Scanning Tunneling Microscopy analysis of space-exposed polymer films  

NASA Technical Reports Server (NTRS)

The characterization of the surface of selected space-exposed polymer films by Scanning Tunneling Microscopy (STM) is reported. Principles of STM, an emerging new technique for materials analysis, are reviewed. The analysis of several films which received up to 5.8 years of low Earth orbital (LEO) exposure onboard the NASA Long Duration Exposure Facility (LDEF) is discussed. Specimens included FEP Teflon thermal blanket material, Kapton film, and several experimental polymer films. Ultraviolet and atomic oxygen-induced crazing and erosion are described. The intent of this paper is to demonstrate how STM is enhancing the understanding of LEO space environmental effects on polymer films.

Kalil, Carol R.; Young, Philip R.

1993-01-01

315

NMR relaxometry measurements of Fricke gel dosimeters exposed to neutrons  

NASA Astrophysics Data System (ADS)

Fricke infused gel matrices offer several features making them suitable for dosimetric applications; among these there are tissue equivalence, low cost and ease of preparation. Their nuclear magnetic resonance (NMR) relaxation properties can be used as a radiation detector for the dosimetry of beams used in cancer therapy. In recent years neutron capture therapy has been resumed for the treatment of various types of cancer and it requires three-dimensional mapping of the neutron fields. In this work, we investigated this particular application through NMR relaxometry and MR imaging of Fricke gels exposed to neutrons. We analyzed both the R1 and R2 relaxation rates, which relate to the longitudinal T1 and transversal T2 relaxation times. In particular, we found that the relaxation rate R2 does not depend on the neutron fluence, whereas the relaxation rate R1 increases linearly with the fluence. The magnetic resonance imaging acquisitions showed that T1-weighted images allow the characterization of samples exposed to different neutron fluences.

Marrale, Maurizio; Brai, Maria; Longo, Anna; Gallo, Salvatore; Tomarchio, Elio; Tranchina, Luigi; Gagliardo, Cesare; D'Errico, Francesco

2014-11-01

316

Exposing the cancer genome atlas as a SPARQL endpoint.  

PubMed

The Cancer Genome Atlas (TCGA) is a multidisciplinary, multi-institutional effort to characterize several types of cancer. Datasets from biomedical domains such as TCGA present a particularly challenging task for those interested in dynamically aggregating its results because the data sources are typically both heterogeneous and distributed. The Linked Data best practices offer a solution to integrate and discover data with those characteristics, namely through exposure of data as Web services supporting SPARQL, the Resource Description Framework query language. Most SPARQL endpoints, however, cannot easily be queried by data experts. Furthermore, exposing experimental data as SPARQL endpoints remains a challenging task because, in most cases, data must first be converted to Resource Description Framework triples. In line with those requirements, we have developed an infrastructure to expose clinical, demographic and molecular data elements generated by TCGA as a SPARQL endpoint by assigning elements to entities of the Simple Sloppy Semantic Database (S3DB) management model. All components of the infrastructure are available as independent Representational State Transfer (REST) Web services to encourage reusability, and a simple interface was developed to automatically assemble SPARQL queries by navigating a representation of the TCGA domain. A key feature of the proposed solution that greatly facilitates assembly of SPARQL queries is the distinction between the TCGA domain descriptors and data elements. Furthermore, the use of the S3DB management model as a mediator enables queries to both public and protected data without the need for prior submission to a single data source. PMID:20851208

Deus, Helena F; Veiga, Diogo F; Freire, Pablo R; Weinstein, John N; Mills, Gordon B; Almeida, Jonas S

2010-12-01

317

Role of exposed metal sites in hydrogen storage in MOFs.  

PubMed

The role of exposed metal sites in increasing the H2 storage performances in metal-organic frameworks (MOFs) has been investigated by means of IR spectrometry. Three MOFs have been considered: MOF-5, with unexposed metal sites, and HKUST-1 and CPO-27-Ni, with exposed Cu(2+) and Ni(2+), respectively. The onset temperature of spectroscopic features associated with adsorbed H2 correlates with the adsorption enthalpy obtained by the VTIR method and with the shift experienced by the H-H stretching frequency. This relationship can be ascribed to the different nature and accessibility of the metal sites. On the basis of a pure energetic evaluation, it was observed that the best performance was shown by CPO-27-Ni that exhibits also an initial adsorption enthalpy of -13.5 kJ mol(-1), the highest yet observed for a MOF. Unfortunately, upon comparison of the hydrogen amounts stored at high pressure, the hydrogen capacities in these conditions are mostly dependent on the surface area and total pore volume of the material. This means that if control of MOF surface area can benefit the total stored amounts, only the presence of a great number of strong adsorption sites can make the (P, T) storage conditions more economically favorable. These observations lead to the prediction that efficient H2 storage by physisorption can be obtained by increasing the surface density of strong adsorption sites. PMID:18533719

Vitillo, Jenny G; Regli, Laura; Chavan, Sachin; Ricchiardi, Gabriele; Spoto, Giuseppe; Dietzel, Pascal D C; Bordiga, Silvia; Zecchina, Adriano

2008-07-01

318

Assessment of genotoxic effects of lead in occupationally exposed workers.  

PubMed

The genotoxicological effects in 200 lead acid storage battery recycling and manufacturing industry workers in Hyderabad along with matched 200 controls were studied. The genetic damage was determined by comet, micronucleus (MN), and chromosomal aberration (CA) test in peripheral blood lymphocytes (PBL). The MN test was also carried out in buccal epithelial cells (BECs). Pb in ambient air, blood Pb (B-Pb) concentrations, and hematological parameters were measured. The superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA) formed were also studied. The results of the present study showed that there was a statistically significant (P?exposed workers in comparison to controls. SOD, GPx, and CAT levels were significantly decreased while GSH and MDA levels increased in exposed group when compared to control group. The present study suggests that environmental health standards should be enforced to control Pb contamination from battery industries to reduce human health risk. PMID:24906834

Chinde, Srinivas; Kumari, Monika; Devi, Kanapuram Rudrama; Murty, Upadhyayula Suryanarayana; Rahman, Mohammed Fazlur; Kumari, Srinivas Indu; Mahboob, Mohammed; Grover, Paramjit

2014-10-01

319

Increased gluconeogenesis in rats exposed to hyper-G stress  

NASA Technical Reports Server (NTRS)

The effect of gluconeogenesis on the levels of plasma glucose and liver glycogen was studied in rats exposed to hyper-G stress. Incorporation of lactate, alanine, or glycerol, labeled with C-14, into plasma glucose and liver glycogen was measured in rats centrifuged at 3.1 G for 0.25, 0.50, and 1.0-hr periods, and was compared to noncentrifuged controls injected with appropriate glycogen precursors. It was found that exposure to G-stress leads to increased incorporation from all three substrates into both plasma glucose and liver glycogen. These early incorporation increases were blocked upon pre-G administration of 5-methoxyindole-2-carboxylic acid, a gluconeogenesis inhibitor, or propanolol, a beta-adrenergic blocker, as well as by adrenodemedullation. Results indicate that the rapid rise in plasma glucose, as well as in liver glycogen in rats exposed to hyper-G stress is due to an increased rate of gluconeogenesis, and that epinephrine, released in response to hyper-G-induced activation of the sympathetic-adrenal system, plays a dominant role during the early stages of hyper-G stress.

Daligcon, B. C.; Oyama, J.; Hannak, K.

1985-01-01

320

HIV Exposed Infants: Rethinking care for a lifelong condition  

PubMed Central

Summary Each year over a million infants are born to HIV infected mothers though with scale up of prevention of mother to child transmission (PMTCT) interventions, only 210,000 of the 1.3 million infants born to mothers with HIV/AIDS in 2012 became infected. Current programmatic efforts directed at infants born to HIV-infected mothers are primarily focused on decreasing their risk of infection, but this emphasis on maternal interventions has meant follow-up of exposed infants has been poor. Programs are struggling to retain this population in care until the end of exposure, typically at the cessation of breastfeeding, between 12 and 24 months of age. But HIV exposure is a life-long condition that continues to impact the health and well-being of a child long after exposure has ended. A better understanding of the impact of HIV on exposed infants is needed and new programs and interventions must take into consideration the long-term health needs of this growing population. The introduction of lifelong treatment for all HIV-infected pregnant women is an opportunity to rethink how we provide services adapted for the long-term retention of mother-infant pairs. PMID:24361628

Sugandhi, N; Rodrigues, J; Kim, MH; Ahmed, S; Amzel, A; Tolle, M; Dzubien, E; Rivadeneira, E; Kellerman, S

2014-01-01

321

Neural Tube Defects In Mice Exposed To Tap Water  

PubMed Central

In May of 2006 we suddenly began to observe neural tube defects (NTDs) in embryos of untreated control mice. We hypothesized the mice were being exposed unknowingly to a teratogenic agent and investigated the cause. Our results suggested that NTDs were not resulting from bedding material, feed, strain or source of the mice. Additionally, mice were negative for routine and comprehensive screens of pathogens. To further test whether the NTDs resulted from infectious or genetic cause localized to our facility, we obtained three strains of timed pregnant mice from commercial suppliers located in 4 different states. All strains and sources of mice arrived in our laboratory with NTDs, implying that commercially available mice were possibly exposed to a teratogen prior to purchase. Our investigation eventually concluded that exposure to tap water was causing the NTDs. The incidence of NTDs was greatest in purchased mice provided tap water and lowest in purchased mice provided distilled deionized water (DDI). Providing mice DDI water for two generations (F2-DDI) eliminated the NTDs. When F2-DDI mice were provided tap water from three different urban areas prior to breeding, their offspring again developed NTDs. Increased length of exposure to tap water significantly increased the incidence of NTDs. These results indicate that a contaminant in municipal tap water is likely causing NTDs in mice. The unknown teratogen appears to have a wide geographic distribution but has not yet been identified. Water analysis is currently underway to identify candidate contaminants that might be responsible for the malformations. PMID:20549630

Mallela, Murali K; Werre, Stephen R; Hrubec, Terry C

2010-01-01

322

Exposing the cancer genome atlas as a SPARQL endpoint  

PubMed Central

The Cancer Genome Atlas (TCGA) is a multidisciplinary, multi-institutional effort to characterize several types of cancer. Datasets from biomedical domains such as TCGA present a particularly challenging task for those interested in dynamically aggregating its results because the data sources are typically both heterogeneous and distributed. The Linked Data best practices offer a solution to integrate and discover data with those characteristics, namely through exposure of data as Web services supporting SPARQL, the Resource Description Framework query language. Most SPARQL endpoints, however, cannot easily be queried by data experts. Furthermore, exposing experimental data as SPARQL endpoints remains a challenging task because, in most cases, data must first be converted to Resource Description Framework triples. In line with those requirements, we have developed an infrastructure to expose clinical, demographic and molecular data elements generated by TCGA as a SPARQL endpoint by assigning elements to entities of the Simple Sloppy Semantic Database (S3DB) management model. All components of the infrastructure are available as independent Representational State Transfer (REST) Web services to encourage reusability, and a simple interface was developed to automatically assemble SPARQL queries by navigating a representation of the TCGA domain. A key feature of the proposed solution that greatly facilitates assembly of SPARQL queries is the distinction between the TCGA domain descriptors and data elements. Furthermore, the use of the S3DB management model as a mediator enables queries to both public and protected data without the need for prior submission to a single data source. PMID:20851208

Deus, Helena F.; Veiga, Diogo F.; Freire, Pablo R.; Weinstein, John N.; Mills, Gordon B.; Almeida, Jonas S.

2011-01-01

323

Longitudinal study of children exposed to sulfur oxides  

SciTech Connect

This study is a longitudinal comparison of the health of children exposed to markedly different concentrations of sulfur dioxide and moderately different concentrations of particulate sulfate. The four groups of subjects lived in two areas of one smelter town and in two other towns, one of which was also a smelter town. In the area of highest pollution, children were intermittently exposed to high SO/sub 2/ levels (peak three-hour average concentration exceeded 2,500 micrograms/m3) and moderate particulate SO/sub 4/= levels (average concentration was 10.1 micrograms/m3). When the children were grouped by the four gradients of pollution observed, the prevalence of cough (measured by questionnaire) correlated significantly with pollution levels (trend chi-square = 5.6, p = 0.02). No significant differences in the incidence of cough or other symptoms occurred among the groups of subjects over three years, and pulmonary function and lung function growth over the study were roughly equal among all the groups. These results suggest that intermittent elevations in SO/sub 2/ concentration, in the presence of moderate particulate SO/sub 4/= concentration, produced evidence of bronchial irritation in the subjects, but no chronic effect on lung function or lung function growth was detected.

Dodge, R.; Solomon, P.; Moyers, J.; Hayes, C.

1985-05-01

324

HIV-exposed infants: rethinking care for a lifelong condition.  

PubMed

Each year over a million infants are born to HIV-infected mothers. With scale up of prevention of mother-to-child transmission (PMTCT) interventions, only 210?000 of the 1.3 million infants born to mothers with HIV/AIDS in 2012 became infected. Current programmatic efforts directed at infants born to HIV-infected mothers are primarily focused on decreasing their risk of infection, but an emphasis on maternal interventions has meant follow-up of exposed infants has been poor. Programs are struggling to retain this population in care until the end of exposure, typically at the cessation of breastfeeding, between 12 and 24 months of age. But HIV exposure is a life-long condition that continues to impact the health and well being of a child long after exposure has ended. A better understanding of the impact of HIV on exposed infants is needed and new programs and interventions must take into consideration the long-term health needs of this growing population. The introduction of lifelong treatment for all HIV-infected pregnant women is an opportunity to rethink how we provide services adapted for the long-term retention of mother-infant pairs. PMID:24361628

Sugandhi, Nandita; Rodrigues, Jessica; Kim, Maria; Ahmed, Saeed; Amzel, Anouk; Tolle, Mike; Dziuban, Eric J; Kellerman, Scott E; Rivadeneira, Emilia

2013-11-01

325

Behavioral modification of estuarine fish exposed to sulfur dioxide  

SciTech Connect

This study was designed to determine the avoidance responses of juvenile striped bass (Morone saxatilis) and Atlantic menhaden (Brevoortia tyrannus) exposed to sulfur dioxide (sulfite) at acclimation temperatures of 15, 20, 25, and 30/sup 0/C. Predictive models were developed and compared for each species at each acclimation temperature. Striped bass avoided 2.2, 2.3, 3.0, and 3.5 mg sulfite/l at 15, 20, 25, and 30/sup 0/C, respectively. Atlantic menhaden avoided 3.2, 3.6, 2.9, and 3.0 mg sulfite/l at acclimation temperatures of 15, 20, 25, and 30/sup 0/C, respectively. Acclimation temperature was an important factor influencing the avoidance response of each species exposed to sulfur dioxide. Striped bass avoided lower concentrations of sulfite than Atlantic menhaden at 15 and 20/sup 0/C. Both species avoided approximately the same concentration of sulfite at 25/sup 0/C. Atlantic menhaden avoided lower concentrations of sulfur dioxide than striped bass at 30/sup 0/C. 24 references, 2 figures, 3 tables.

Hall, L.W. Jr.; Burton, D.T.; Graves, W.C.; Margrey, S.L.

1984-01-01

326

Behavioral modification of estuarine fish exposed to sulfur dioxide.  

PubMed

This study was designed to determine the avoidance responses of juvenile striped bass (Morone saxatilis) and Atlantic menhaden (Brevoortia tyrannus) exposed to sulfur dioxide (sulfite) at acclimation temperatures of 15, 20, 25, and 30 degrees C. Predictive models were developed and compared for each species at each acclimation temperature. Striped bass avoided 2.2, 2.3, 3.0, and 3.5 mg sulfite/l at 15, 20, 25, and 30 degrees C, respectively. Atlantic menhaden avoided 3.2, 3.6, 2.9, and 3.0 mg sulfite/l at acclimation temperatures of 15, 20, 25, and 30 degrees C, respectively. Acclimation temperature was an important factor influencing the avoidance response of each species exposed to sulfur dioxide. Striped bass avoided lower concentrations of sulfite than Atlantic menhaden at 15 and 20 degrees C. Both species avoided approximately the same concentration of sulfite at 25 degrees C. Atlantic menhaden avoided lower concentrations of sulfur dioxide than striped bass at 30 degrees C. PMID:6492212

Hall, L W; Burton, D T; Graves, W C; Margrey, S L

1984-01-01

327

Characterization of Specimens Exposed in a Li Loop  

SciTech Connect

A monometallic V-4Cr-4Ti thermal convection loop was run for 2,350 h with a peak temperature of 700 C and Li flow rate of 2-3 cm/s. Specimens of V-4Cr-4Ti exposed in the hot and cold leg were tensile tested in vacuum at 500 C showing an increase in the 0.2% yield and ultimate tensile strengths and a decrease in the serration amplitude with decreasing exposure temperature in the loop. However, only minor changes in ductility were measured. With the higher temperature exposures, there was a decrease in Vickers hardness measured but little change in the grain size. Characterization of the microstructure after exposure at 627 C in the loop showed an increase in the density of Ti- and N-rich grain boundary and matrix precipitates near the specimen surface after exposure corresponding to an increase in the hardness in the near-surface region. Two-layer V/Y2O3 coatings on V-4Cr-4Ti substrates also were exposed in the loop and initial room temperature characterization has been conducted.

Unocic, Kinga A [ORNL] [ORNL; Lance, Michael J [ORNL] [ORNL; Pint, Bruce A [ORNL] [ORNL

2013-01-01

328

Endocrinologic studies in men exposed occupationally to carbon disulfide.  

PubMed

The effect of long-term occupational exposure to CS2 on various endocrinologic parameters was studied in 15 exposed men and 16 age-matched controls. Duration of exposure varied between 10 and 36 yr. The CS2 concentrations in the viscose rayon plant have been below the Finnish threshold limit value of 30 mg/m3 (10 ppm) under normal operating conditions for the past 10 yr. Before this the exposure was considerably greater. Of the various endocrinologic parameters, serum follicle stimulating hormone (FSH) and luteinizing hormone (LH) were significantly increased in the exposed group, seven workers having values above the reference limit. This was taken as a sign of primary gonadal insufficiency, which was considered only latent as serum testosterone values were unaffected. No changes were seen in serum prolactin values before or after stimulation with thyrotropin releasing hormone (TRH). No disturbance was seen in thyroid function as evaluated by serum thyroxine (T4), free thyroxine index (FT1), triiodothyronine (T3), and the thyrotropin response to TRH. Serum cortisol was also unchanged. These results may reflect high exposure during past decades rather than exposure to the present low CS2 concentrations. PMID:6793731

Wägar, G; Tolonen, M; Stenman, U H; Helpiö, E

1981-01-01

329

Cerebral blood flow in patients (PTS) exposed to neurotoxic chemicals  

SciTech Connect

Exposure to neurotoxic chemicals as pesticides, glues, solvents, etc. are known to induce neurologic and psychiatric symptomatology. We report on 72 pts, 33 young pts, 8 males, and 26 females, age 55 (7) yrs, 15 of them exposed to pesticides, and 37 to solvents. They were studied with quantitative and qualitative analysis of rCBF performed with 30 mCi of Xe-133 (Xe) by inhalation followed by 30 mCi of Tc-HMPAO given IV. Imaging was performed with a brain dedicated system, and distribution of rCBF was assessed with automatic ROI definition, and HMPAO normalized to maximal pixel activity in the brain. Results of Xe rCBF are expressed as mean and (S.D.) in ml/min/100g, and HMPAO as mean and (S.D.) uptake per ROI and compared with age-matched controls, 10 young and 20 elderly individuals, and also to a group of 36 elderly chronic fatigue pts (CFS), and 26 depression pts. CBF was diminished in young and elderly, 45 (7) and 40 (7) ml/min 100g, p<0.02 for both groups. Thus we conclude that pts exposed to chemicals present with diminished CBF, worse in elderly in the right dorsal frontal and parietal lobes, and in young, in left dorsal frontal and temporal lobes. These findings are significantly different from observations in pts and chronic fatigue and depression.

Heuser, G.; Mena, I.; Thomas, C. [Harbor-UCLA Medical Center, Torrance, CA (United States)] [and others

1994-05-01

330

Methicillin Resistant Staphylococcus aureus Carriage, Antibiotic Resistance and Molecular Pathogenicity among Healthy Individuals Exposed and Not Exposed to Hospital Environment  

PubMed Central

Background: Healthcare workers as well as healthy community-dwelling individuals may be colonised by methicillin-resistant Staphylococcus aureus (MRSA). Healthcare workers who carry MRSA may transmit it to patients, causing various nosocomial infections. Literature shows that the differences between MRSA isolated from healthcare settings and from community settings, with regard to multi-drug resistance (traditionally exhibited by the former) and possession of pvl genes (traditionally exhibited by the latter), is diminishing due to a large community reservoir and increasing influx of community harboured strains into the hospital. However, there is no literature on the current scenario in India. Aims and Objectives: This study examines the influence of exposure to hospital environment on MRSA carriage, antimicrobial resistance patterns of MRSA, and the presence of genes encoding five extracellular pathogenicity determinants (pvl, sea, seb, tsst-1 and hly a). Materials and Methods: Nasal, throat and palmar swabs were collected from 119 nursing students of the age group 18-23 years (exposed group) and 100 age matched pharmacy students (non-exposed group). S. aureus was identified and antibiogram obtained as per Clinical and Laboratory Standards Institute (CLSI) guidelines. MRSA was detected by cefoxitin disc diffusion test and by growth on oxacillin screen agar as per CLSI guidelines. Conventional PCR was performed for mecA, pvl, sea, seb, tsst-1 and hly a. Results: The differences in carrier rates, antibiotic resistance patterns and expression of extracellular pathogenicity determinants between MRSA isolates from the two study groups were not significant, and pvl was found in all the MRSA isolates. Conclusion: The nursing students carried MRSA strains similar to those carried by the non-exposed group. Our results suggest that healthcare workers could act as a link and transmit MRSA acquired from the community to patients.

Krishnamurthy, Veena; Renushri, Bhadravati Virupaksha; Nagaraj, Elkal Rajappa

2014-01-01

331

Cytogenetic analysis of an exposed-referent study: perchloroethylene-exposed dry cleaners compared to unexposed laundry workers  

PubMed Central

Background Significant numbers of people are exposed to tetrachloroethylene (perchloroethylene, PCE) every year, including workers in the dry cleaning industry. Adverse health effects have been associated with PCE exposure. However, investigations of possible cumulative cytogenetic damage resulting from PCE exposure are lacking. Methods Eighteen dry cleaning workers and 18 laundry workers (unexposed controls) provided a peripheral blood sample for cytogenetic analysis by whole chromosome painting. Pre-shift exhaled air on these same participants was collected and analyzed for PCE levels. The laundry workers were matched to the dry cleaners on race, age, and smoking status. The relationships between levels of cytological damage and exposures (including PCE levels in the shop and in workers' blood, packyears, cumulative alcohol consumption, and age) were compared with correlation coefficients and t-tests. Multiple linear regressions considered blood PCE, packyears, alcohol, and age. Results There were no significant differences between the PCE-exposed dry cleaners and the laundry workers for chromosome translocation frequencies, but PCE levels were significantly correlated with percentage of cells with acentric fragments (R2 = 0.488, p < 0.026). Conclusions There does not appear to be a strong effect in these dry cleaning workers of PCE exposure on persistent chromosome damage as measured by translocations. However, the correlation between frequencies of acentric fragments and PCE exposure level suggests that recent exposures to PCE may induce transient genetic damage. More heavily exposed participants and a larger sample size will be needed to determine whether PCE exposure induces significant levels of persistent chromosome damage. PMID:21392400

2011-01-01

332

Cytogenetic analysis of an exposed-referent study: perchloroethylene-exposed dry cleaners compared to unexposed laundry workers  

Microsoft Academic Search

Background  Significant numbers of people are exposed to tetrachloroethylene (perchloroethylene, PCE) every year, including workers in\\u000a the dry cleaning industry. Adverse health effects have been associated with PCE exposure. However, investigations of possible\\u000a cumulative cytogenetic damage resulting from PCE exposure are lacking.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Eighteen dry cleaning workers and 18 laundry workers (unexposed controls) provided a peripheral blood sample for cytogenetic\\u000a analysis by

James D Tucker; Karen J Sorensen; Avima M Ruder; Lauralynn Taylor McKernan; Christy L Forrester; Mary Ann Butler

2011-01-01

333

30 CFR 817.13 - Casing and sealing of exposed underground openings: General requirements.  

Code of Federal Regulations, 2010 CFR

...requirements. Each exploration hole, other drillhole or borehole, shaft, well, or other exposed underground opening...area and adjacent area. Each exploration hole, drill hole or borehole or well that is uncovered or exposed by mining...

2010-07-01

334

Biomarkers in humans exposed to polycyclic aromatic hydrocarbons  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAH) have been identified as a major source of carcinogenic risk in the coke-oven industry. This study evaluates following markers: personal exposure to PAH, DNA adducts, chromosomal aberrations and sister chromatid exchanges (SCE), glutathione S-transferase M1 (GSTM1) and N-acetyltransferase 2 (NAT2) polymorphisms. 23 top side coke-oven workers and 13 unexposed workers employed in the same plant at Kosice, Slovakia were studied. Personal monitors were used to measure carcinogenic PAH exposure during 8 h of working shift prior the collection of blood and urine samples. Personal exposure to eight carcinogenic PAHs ranged from 0.6 to 632 {mu}g/m{sup 3} and from 0.07 to 0.62 {mu}g/m{sup 3} for exposed and control groups, respectively. Based on the values of individual persons, the positive significant correlations were found between DNA adducts detected in WBC and LYM (Spearman r=0.451, p=0.044), between DNA adducts and SCE (r=0.363, p=0.034) and between AB.C. and SCE-H (SCE evaluated as the index of heterogeneity H-variance/mean: r=0.381, p=0.024). Using individual PAH exposure data the following significant correlations between exposure and biomarkers were found: WBC-DNA adducts (r=0.325;p=0.058);SCE-H (r=0.467, p=0.007). Groupwise comparison of the exposed and control groups (Mann-Whitney U-test) showed significantly increased values of SCE (6.71{+-}1.20 vs. 5.20 {+-}1.16, respectively) and DNA adducts in WBC and LYM (2.70{+-}0.74 vs 1.94{+-}0.51 adducts/10{sup 8} nucleotides; 2.46{+-}0.83 vs. 1.60{+-}0.32 adducts/10{sup 8}nucleotides, respectively). No influence of the smoking habits on the biomarkers was detectable in exposed or unexposed individuals. Multifactor analysis of variance taking into account confounding factors such as GSTM1, NAT2, diet and adjusting the data for age and smoking clearly showed the effect of exposure on DNA adducts, AB.C and SCE-H.

Binkova, B.; Topinka, J.; Mrackova, G. [Institute of Hygiene of Central Bohemia and Institute of Experimental Medicine, Prague (Czechoslovakia)] [and others

1997-10-01

335

Time Course of Sensory Eye Irritation in Humans Exposed to N-Butanol and 1-Octene  

Microsoft Academic Search

In this study, we investigated the time course effect of sensory eye irritation in 16 subjects exposed (i.e., eye only) to n-butanol and 1-octene. Half the subjects were exposed to n-butanol, and the remaining subjects were exposed to 1-octene. Each subject was studied on 5 different days; during each day each subject was exposed in three runs (i.e., run 1,

Anne Hempel-Jørgensen; S. K. Kjaergaard; L. Môlhave; H. K. Hudnell

1999-01-01

336

Children Exposed to Community Violence or War\\/Terrorism: Current Status and Research Directions—Introduction  

Microsoft Academic Search

This issue of Clinical Child and Family Psychology Review, “Children Exposed to Community Violence or War\\/Terrorism: Current Status and Research Directions,” addresses the current status of our knowledge as well as critical research needs in the area of children exposed to violence outside the family. Although much has been learned in recent years about children exposed to violence, significant research

Ronald J. Prinz; Margaret M. Feerick

2003-01-01

337

Neurocognitive Changes among Elderly Exposed to PCBs\\/PCDFs in Taiwan  

Microsoft Academic Search

BACKGROUND: In 1979 approximately 2,000 people were exposed to polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs) due to ingestion of contaminated cooking oil in Taiwan. Although a previous study has shown delayed developmental milestones and poorer neurocognitive functioning in children born to exposed mothers, it is unclear whether neurocogni- tive functioning was impaired in people who were directly exposed to

Kao-Chang Lin; Nai-Wen Guo; Pei-Chien Tsai; Chiu-Yueh Yang; YueLiang Leon Guo

2007-01-01

338

Oxidative status in rat kidney exposed to petroleum hydrocarbons  

PubMed Central

Objective: The study investigates the possible role of oxidative stress on renal tissues in association with petroleum hydrocarbon-induced nephrotoxicity. Materials and Methods: Rats of comparable weights were randomly distributed into 10 groups: Control and groups exposed to kerosene, petrol, and diesel via inhalation, contamination by food, and contamination by water. The exposure lasted for eight weeks. Results: Exposure to petroleum hydrocarbon led to significant rise in serum urea and creatinine, and renal tissue malondialdehyde. It also caused significant reduction in urinary urea and creatinine, and reduced glutathione, superoxide dismutase, and catalase activities of renal tissue homogenate. However, serum and urine concentrations of albumin and total protein were comparable in all groups. Conclusion: Results from this study shows that exposure to petroleum hydrocarbon led to renal dysfunction via oxidative stress, increasing lipid peroxidation and reducing the antioxidant defense mechanism. PMID:23633852

Azeez, Oyebisi M.; Akhigbe, Roland E.; Anigbogu, Chikodi N.

2013-01-01

339

Nanoindentation Study of Na-Geopolymers Exposed to High Temperatures  

NASA Astrophysics Data System (ADS)

This paper reports the usefulness of nanoindentation as a characterization and monitoring tool for studying thermal behaviour of Geopolymer materials. The influence of the manufacturing process of Na-Geopolymers in their micro-mechanical properties and thermal behaviour has been studied. Two types of metakaolin-based geopolymer panels with almost identical composition were prepared by injection and pouring methods. Micro-mechanical properties of the two samples exposed to high temperatures up to 1000 ºC were studied by nanoindentation technique, supplemented by X-ray diffraction (XRD), Nuclear magnetic resonance (NMR), Thermogravimetric analysis (TGA) and Microscopy. Remarkable differences in micro-mechanical properties and thermal behaviour between the two samples were found. Statistical nanoindentation has been successfully used to provide information about the micro-mechanical properties of different phases in the material and their volume distributions.

Beleña, I.; Zhu, W.

340

PTSD symptoms in young children exposed to intimate partner violence.  

PubMed

Intimate partner violence (IPV) places infants and young children at risk for development of trauma symptoms. However, this is an understudied consequence of IPV because young children pose particular difficulties for assessment of trauma symptoms. The authors collected maternal reports on mothers' and children's posttraumatic stress disorder (PTSD) symptoms and IPV yearly, from ages 1 to 7. Approximately half of the children exposed to IPV at each time period developed some trauma symptoms, and frequency of IPV witnessed was associated with PTSD symptoms. Maternal and child PTSD symptoms were correlated, suggesting that young children may be particularly vulnerable to relational PTSD due to their close physical and emotional relationship with their parents. PMID:23420836

Levendosky, Alytia A; Bogat, G Anne; Martinez-Torteya, Cecilia

2013-02-01

341

Reproductive adaptation in Drosophila exposed to oxygen-enriched atmospheres  

NASA Technical Reports Server (NTRS)

Ten successive generations of a Drosophila melanogaster population were exposed to an atmospheric mix of 50% oxygen/50% nitrogen at standard pressure. This atmospheric mix has been shown to be toxic to this species and causes significantly shortened life span. By the fifth generation, survivorship and life span for the first 25-30 days were identical to control populations and total life span was shorter by only a few days. Egg-laying rates were stable in the experimental populations but below those of the controls. Hatching success was identical between experimental and control populations. Even though the egg-laying rates were lower in 50% oxygen, it was concluded that the population had adapted and could maintain a stable population in these conditions. The near-normal life spans, normal hatching rates, and overall population stability, exhibited following five generations of adaptation, were considered sufficient to allow continued reproduction in spite of a reduced egg-laying rate.

Kloek, G.; Winkle, L.

1979-01-01

342

Acute physiological responses of squirrel monkeys exposed to hyperdynamic environments  

NASA Technical Reports Server (NTRS)

Physiological and behavioral responses to a hyperdynamic environment were examined in four adult male squirrel monkeys. After baseline monitoring at 1 G, monkeys were exposed to one of three conditions: (1) +2 Gz for 60 minutes, (2) +2.9 Gz max for 8 minutes (simulating Space Shuttle launch), or (3) +1.7 Gz max for 19 minutes (simulating Space Shuttle reentry). During all experimental conditions, heart rate rose, and colonic temperature began to decline within the first ten minutes of centrifugation and decreased by as much as 2 C in some instances. Behaviorally, during centrifugation, the monkeys seemed to exhibit drowsiness and fall asleep, an observation not made during the control period. It is concluded that primates are susceptible to acute hyperdynamic field exposure.

Fuller, C. A.

1984-01-01

343

Agent Orange: management of patients exposed in Vietnam.  

PubMed

Since the Vietnam War ended in 1975, numerous studies have been conducted to determine if an association exists between Agent Orange exposure and certain disabling conditions specifically cancer. Although a definite causal relationship has not yet been established, sufficient data associate Agent Orange with certain conditions. Because of their advancing age similar to other baby boomers, Vietnam veterans are at a higher risk of developing malignancies. However, their exposure to Agent Orange also may increase their risk for cancer and other associated diseases. This article examines the latest findings of scientific research sponsored by the Department of Veterans Affairs and discusses the importance of well-informed oncology nurses when providing care for patients with cancer exposed to Agent Orange. PMID:12793339

Beaulieu, Anne; Fessele, Kristen

2003-01-01

344

Laboratory animal allergy: a clinical survey of an exposed population.  

PubMed Central

A clinical survey of workers exposed to laboratory animals in a pharmaceutical company was designed to discover the prevalence and severity of symptoms of laboratory animal allergy (LAA). The overall prevalence of the condition was 30%, and two distinguishable LAA syndromes, termed regional and progressive LAA, were found. The first is characterised by rhinitis with negative skin prick tests. The second consists of rhinitis leading progressively to asthma with positive prick tests. Prick tests were useful diagnostically only in the latter. Atopes were shown not to be at special risk of developing LAA, but if they did so were more likely to progress to asthma. The implications for selection and management policy are outlined and specific measures for the further study of LAA are proposed. PMID:7470403

Slovak, A J; Hill, R N

1981-01-01

345

Health effects among refrigeration repair workers exposed to fluorocarbons.  

PubMed Central

Refrigeration repair workers may be intermittently exposed to fluorocarbons and their thermal decomposition products. A case of peripheral neuropathy (distal axonopathy) in a commercial refrigeration repairman prompted an epidemiological investigation of the health of refrigeration repair workers. No additional cases of peripheral neuropathy were identified among the 27 refrigeration repair workers studied. A reference group of 14 non-refrigeration repair workers was also studied. No differences were noted between groups for the ulnar (motor and sensory), median (motor and sensory), peroneal, sural, or tibial nerve conduction velocities. Refrigeration repair workers reported palpitations and lightheadedness significantly more often than workers in the reference group. No clinical neurological or electroneurophysiological abnormalities were detected in eight refrigeration repair workers followed up for three years during continuous employment. PMID:3004555

Campbell, D D; Lockey, J E; Petajan, J; Gunter, B J; Rom, W N

1986-01-01

346

Mortality among benzene-exposed workers in China  

SciTech Connect

A large cohort of 74,828 benzene-exposed and 35,805 nonexposed workers employed between 1972 and 1987 in 12 cities in China was followed to determine mortality from all causes. Mortality was slightly increased among workers with greater cumulative exposure to benzene (p{sub trend} <0.05), but this excess was largely due to cancer deaths (p{sub trend} <0.01). Deaths due to lymphatic and hematopoietic malignancies (p{sub trend} = 0.01) and lung cancer (P{sub trend} = 0.01) increased with increasing cumulative exposure to benzene. Investigations continue to relate benzene exposure to specific lymphatic and hematopoietic malignancies and other causes of death. 25 refs., 2 tabs.

Hayes, R.B.; Dosemeci, M.; Wacholder, S. [National Institutes of Health, Bethesda, MD (United States)] [and others

1996-12-01

347

Lack of exposed ice inside lunar south pole Shackleton Crater.  

PubMed

The inside of Shackleton Crater at the lunar south pole is permanently shadowed; it has been inferred to hold water-ice deposits. The Terrain Camera (TC), a 10-meter-resolution stereo camera onboard the Selenological and Engineering Explorer (SELENE) spacecraft, succeeded in imaging the inside of the crater, which was faintly lit by sunlight scattered from the upper inner wall near the rim. The estimated temperature of the crater floor, based on the crater shape model derived from the TC data, is less than approximately 90 kelvin, cold enough to hold water-ice. However, at the TC's spatial resolution, the derived albedo indicates that exposed relatively pure water-ice deposits are not on the crater floor. Water-ice may be disseminated and mixed with soil over a small percentage of the area or may not exist at all. PMID:18948501

Haruyama, Junichi; Ohtake, Makiko; Matsunaga, Tsuneo; Morota, Tomokatsu; Honda, Chikatoshi; Yokota, Yasuhiro; Pieters, Carle M; Hara, Seiichi; Hioki, Kazuyuki; Saiki, Kazuto; Miyamoto, Hideaki; Iwasaki, Akira; Abe, Masanao; Ogawa, Yoshiko; Takeda, Hiroshi; Shirao, Motomaro; Yamaji, Atsushi; Josset, Jean-Luc

2008-11-01

348

Susceptible-infected-recovered and susceptible-exposed-infected models  

NASA Astrophysics Data System (ADS)

Two stochastic epidemic lattice models, the susceptible-infected-recovered and the susceptible-exposed-infected models, are studied on a Cayley tree of coordination number k. The spreading of the disease in the former is found to occur when the infection probability b is larger than bc = k/2(k - 1). In the latter, which is equivalent to a dynamic site percolation model, the spreading occurs when the infection probability p is greater than pc = 1/(k - 1). We set up and solve the time evolution equations for both models and determine the final and time-dependent properties, including the epidemic curve. We show that the two models are closely related by revealing that their relevant properties are exactly mapped into each other when p = b/[k - (k - 1)b]. These include the cluster size distribution and the density of individuals of each type, quantities that have been determined in closed forms.

Tomé, Tânia; de Oliveira, Mário J.

2011-03-01

349

Integrated biomarker responses in zebrafish exposed to sulfonamides.  

PubMed

Dispersed pharmaceuticals such as sulfonamides pose a threat to aquatic ecosystems. We evaluated potential biomarkers of sulfonamide exposure using an extended zebrafish (Danio rerio) toxicity test. The tested sulfonamides induced obvious effects on spontaneous swimming activity and heartbeat rate in zebrafish. Glutathione S-transferase (GST) and malondialdehyde (MDA) were examined to reflect the biomarker response of zebrafish exposed to three sulfonamides (sulfamethoxazole, sulfadiazine (SDZ) and sulfadimidine). Both GST and MDA showed time-dependent responses to sulfonamide exposure. GST activity was significantly increased after exposure to sulfonamides for 3 days, while MDA concentration reached a maximum during the first day and then declined. These results suggest that MDA may be a more sensitive biomarker of sulfonamide toxicity than GST. These investigations demonstrated that SDZ was a typical inducer of metabolic enzymes, suggesting that it poses a potential ecotoxicological risk to aquatic ecosystems. PMID:25136777

Lin, Tao; Yu, Shilin; Chen, Yanqiu; Chen, Wei

2014-09-01

350

DNA damage in Wistar rats exposed to dithiocarbamate pesticide mancozeb.  

PubMed

Pesticides are used in large amounts in agriculture and the evaluation of their toxic effects is of major concern to public and environmental health. The aim of the present study was to investigate the genotoxic potential of a commercial formulation of the fungicide mancozeb by the micronucleus test in bone marrow and the comet assay in total blood of Wistar rats. Adult male Wistar rats were treated with a solution of mancozeb at a concentration of 40 mg/kg/day, administered intraperitoneally for 18 consecutive days, and compared to a control group. The results indicate that mancozeb induced significantly higher DNA damage as detected by the comet assay and increased the frequency of micronuclei. The results show that mancozeb is genotoxic and may adversely affect the DNA integrity of exposed organisms. PMID:25152054

Goldoni, A; Klauck, C R; Da Silva, S T; Da Silva, M D; Ardenghi, P G; Da Silva, L B

2014-01-01

351

Neurobehavioral changes among shipyard painters exposed to solvents  

SciTech Connect

Painters in three shipyards, exposed to a wide variety of solvents, were examined. A short battery of performance tests, a detailed occupational history, and a special questionnaire to assess acute (prenarcotic, transitory) and chronic (persistent) neurologic symptoms was administered. The results of the neurobehavioral performance tests demonstrated decrements in central nervous system function in painters when compared with a control group matched for age, sex, race, and education. The prevalence of reported acute neurological symptoms among painters was increased significantly compared to other occupational groups in the same yards; for chronic, persistent symptoms the difference was not statistically significant. Performance test scores were significantly, negatively correlated with chronic symptoms but not with acute symptoms. No significant correlations between performance test scores and duration of solvent exposure or between symptoms and duration of solvent exposure were observed. The reversibility of such symptoms and of decrements in central nervous system function after cessation of exposure is still uncertain.

Valciukas, J.A.; Lilis, R.; Singer, R.M.; Glickman, L.; Nicholson, W.J.

1985-01-01

352

Nickel-exposed workers in China: a cohort study.  

PubMed

There are more than 50 000 workers in Jinchuan Group Co, Ltd (JNMC). Since all staff in JNMC are eligible for a medical examination every two years, only 23 484 nickel-exposed subjects who participated in medical examination were included in this study. Their data, collected from June 22, 2011 to September 28, 2012, in a comprehensive epidemiological survey and during medical examinations, permitted an extensive evaluation of the relation between metal exposure, gene, epigenetics and risk of human diseases. Their lifestyle investigation showed that the overall prevalence of current smokers, alcohol drinkers, and tea drinkers was 39.1%, 19.7%, and 55.2%, respectively. The prevalence of hypertension, allergic rhinitis and cholecystitis , the top 3 prevalent diseases, was 11.7%, 11.0%, and 8.9%, respectively. PMID:24709102

Bai, Ya Na; Yang, Ai Min; Yagn, Ai Min; Pu, Hong Quan; He, Jie; Cheng, Ning; Zheng, Tong Zhang; Dai, Min; Zhang, Ya Wei; Bassing, Bryan A; Wang, Qiu Ying

2014-03-01

353

Chromosome Aberration in Human Blood Lymphocytes Exposed to Energetic Protons  

NASA Technical Reports Server (NTRS)

During space flight, astronauts are exposed to a space radiation consisting of high-energy protons, high charge and energy (HZE) nuclei, as well as secondary particles that are generated when the primary particles penetrate the spacecraft shielding. Secondary particles have a higher LET value than primary protons and therefore expected to have a higher relative biological effectiveness (RBE). To investigate this theory, we exposed human peripheral blood lymphocytes to protons with energies of 250 MeV, 800MeV, 2 GeV, or 2.5 GeV. LET values for these protons ranged from 0.4 to 0.2 keV/micrometer. and doses ranged from 0.2 to 3 Gy. Over this energy the probability of nuclear reaction leading to secondary radiation, and the multiplicity of reaction produces such as neutrons and mesons increases substantially. The effect of aluminum and polyethylene shielding was also assessed using the 2 GeV and 2.5GeV proton beams. After exposure lymphocytes were stimulated to divide and chromosomes were collected from cells in the first G2 and metaphase cell cycle after exposure using a chemical induced premature chromosome condensation (PCC) technique. Dose response data for chromosome damage was analyzed using the fluorescence in situ hybridization (FISH) chromosome painting technique. Selected samples were also analyzed with multicolor FISH (mFISH) and multicolor banding FISH (mBAND) techniques. Data indicates that the dose response for simple-type exchanges is similar for proton and gamma exposure, whereas protons induce higher yields of complex exchanges that are LET dependent. RBE values will be presented for each proton energy, and the effects of shielding and possible cytogenetic signatures of proton exposure will be discussed.

Hada, M.; George, Kerry A.; Cucinotta, F. A.

2008-01-01

354

Damage assessment in CFRP laminates exposed to impact fatigue loading  

NASA Astrophysics Data System (ADS)

Demand for advanced engineering composites in the aerospace industry is increasing continuously. Lately, carbon fibre reinforced polymers (CFRPs) became one of the most important structural materials in the industry due to a combination of characteristics such as: excellent stiffness, high strength-to-weight ratio, and ease of manufacture according to application. In service, aerospace composite components and structures are exposed to various transient loads, some of which can propagate in them as cyclic impacts. A typical example is an effect of the wind gusts during flight. This type of loading is known as impact fatigue (IF); it is a repetition of low-energy impacts. Such loads can cause various types of damage in composites: fibre breaking, transverse matrix cracking, de-bonding between fibres and matrix and delamination resulting in reduction of residual stiffness and loss of functionality. Furthermore, this damage is often sub-surface, which reinforces the need for more regular inspection. The effects of IF are of major importance due its detrimental effect on the structural integrity of components that can be generated after relatively few impacts at low force levels compared to those in a standard fatigue regime. This study utilises an innovative testing system with the capability of subjecting specimens to a series of repetitive impacts. The primary subject of this paper is to assess the damaging effect of IF on the behaviour of drilled CFRP specimens, exposed to such loading. A detailed damage analysis is implemented utilising an X-ray micro computed tomography system. The main findings suggested that at early stages of life damage is governed by o degree splits along the length of the specimens resulting in a 20% reduction of stiffness. The final failure damage scenario indicated that transverse crasks in the 90 degree plies are the main reason for complete delamination which can be translated to a 50% stiffness reduction.

Tsigkourakos, George; Silberschmidt, Vadim V.; Ashcroft, I. A.

2011-07-01

355

Dry heat exposures of surface exposed and embedded Bacillus spores  

NASA Astrophysics Data System (ADS)

Dry heat microbial reduction (DHMR) is the primary technique used to reduce the microbial load of spacecraft and component parts. Often, manufacturing procedures require heating flight hardware to high temperatures for purposes other than planetary protection DHMR. The existing specifications, however, do not allow for additional planetary protection bioburden reduction credit if the hardware is exposed without controlled relative humidity. The intent of this study was to provide adequate data on the DHMR technique to support modification of four aspects of current requirements; expansion of acceptable time and temperature combinations used for spacecraft dry heat microbial reduction processes above 125° C, determining the effect that humidity has on spore lethality as a function of temperature, understanding the lethality for spores with exceptionally high thermal resistance and to investigate the extended exposure requirement for materials that might contain embedded microorganisms. Spores from two bacterial species were tested, B. atrophaeus ATCC 9372 and B. sp. ATCC 29669, under three conditions encompassing 5 temperature points. Embedded experiments utilized a silicone rubber polymer that is commonly used on robotic spacecraft, and surface exposed experiments were performed under both ambient and vacuum-controlled humidity conditions. The results obtained support the use of DHMR protocols that extend the maximum temperature range from 125° C to 170° C, with either controlled or ambient humidity. If implemented, this will give projects bioburden reduction credit for shorter treatments at extended temperatures, and allow spacecraft to be processed in more readily available and less expensive facilities that do not have humidity control, with significant cost and schedule benefits. The study also demonstrated that the required heating time for materials presumed to have embedded bioburden is conservative.

Schubert, Wayne

356

Chromosome aberrations in human blood lymphocytes exposed to energetic protons  

NASA Astrophysics Data System (ADS)

During space flight, astronauts are exposed to space radiation consisting of high-energy protons, high charge and energy (HZE) nuclei, as well as secondary particles that are generated when the primary particles penetrate the spacecraft shielding. Secondary particles have a higher LET value than primary protons and are therefore expected to have a higher relative biological effectiveness (RBE). To investigate this theory, we exposed human peripheral blood lymphocytes to protons with energies of 250 MeV, 800MeV, 2 GeV, or 2.5 GeV. LET values for these protons ranged from 0.4 to 0.2 keV/µm. and doses ranged from 0.2 to 3 Gy. Over this energy range the probability of nuclear reaction leading to secondary radiation, and the multiplicity of reaction products such as neutrons and mesons increases substantially. The effect of aluminum and polyethylene shielding was also assessed using the 2 GeV and 2.5GeV proton beams. After exposure lymphocytes were stimulated to divide and chromosomes were collected from cells in the first G2 and metaphase cell cycle after exposure using a chemical induced premature chromosome condensation (PCC) technique. Dose response data for chromosome damage was analyzed using the fluorescence in situ hybridization (FISH) chromosome painting technique. Selected samples were also analyzed with multicolor FISH (mFISH) and multicolor banding FISH (mBAND) techniques. Data indicates that the dose response for simple-type exchanges is similar for proton and gamma exposure, whereas protons induce higher yields of complex exchanges that are energy dependent. RBE values will be presented for each proton energy, and the effects of shielding and possible cytogenetic signatures of proton exposure will be discussed.

Hada, Megumi; George, Ms Kerry; Cucinotta, Francis A.

357

Fish exposed to BP oil spill 'swim slower' Study finds the speed of mahi-mahi exposed to BP's Gulf of  

E-print Network

Fish exposed to BP oil spill 'swim slower' Study finds the speed of mahi-mahi exposed to BP's Gulf of Mexico oil spill has fallen 37pc The 87-day-long spill dumped an estimated 4.9m barrels of oil in the gulf shortly after the spill, which oil company BP disputed. "The study does not provide any evidence

Grosell, Martin

358

Direct Assessment of Cumulative Aryl Hydrocarbon Receptor Agonist Activity in Sera from Experimentally Exposed Mice and Environmentally Exposed Humans  

PubMed Central

Background Aryl hydrocarbon receptor (AhR) ligands adversely affect many biological processes. However, assessment of the significance of human exposures is hampered by an incomplete understanding of how complex mixtures affect AhR activation/inactivation. Objectives These studies used biological readouts to provide a broader context for estimating human risk than that obtained with serum extraction and gas chromatography/mass spectroscopy (GC/MS)-based assays alone. Methods AhR agonist activity was quantified in sera from dioxin-treated mice, commercial human sources, and polychlorinated biphenyl (PCB)–exposed Faroe Islanders using an AhR-driven reporter cell line. To validate relationships between serum AhR agonist levels and biological outcomes, AhR agonist activity in mouse sera correlated with toxic end points. AhR agonist activity in unmanipulated (“neat”) human sera was compared with these biologically relevant doses and with GC/MS-assayed PCB levels. Results Mouse serum AhR agonist activity correlated with injected dioxin dose, thymic atrophy, and heptomegaly, validating the use of neat serum to assess AhR agonist activity. AhR agonist activity in sera from Faroe Islanders varied widely, was associated with the frequency of recent pilot whale dinners, but did not correlate with levels of PCBs quantified by GC/MS. Surprisingly, significant “baseline” AhR activity was found in commercial human sera. Conclusions An AhR reporter assay revealed cumulative levels of AhR activation potential in neat serum, whereas extraction may preclude detection of important non-dioxin-like biological activity. Significant levels of AhR agonist activity in commercial sera and in Faroe Islander sera, compared with that from experimentally exposed mice, suggest human exposures that are biologically relevant in both populations. PMID:20435556

Schlezinger, Jennifer J.; Bernard, Pamela L.; Haas, Amelia; Grandjean, Philippe; Weihe, Pal; Sherr, David H.

2010-01-01

359

Mutagenesis in bacterial spores exposed to space and simulated martian conditions: data from the EXPOSE-E spaceflight experiment PROTECT.  

PubMed

As part of the PROTECT experiment of the EXPOSE-E mission on board the International Space Station (ISS), the mutagenic efficiency of space was studied in spores of Bacillus subtilis 168. After 1.5 years' exposure to selected parameters of outer space or simulated martian conditions, the rates of induced mutations to rifampicin resistance (Rif(R)) and sporulation deficiency (Spo(-)) were quantified. In all flight samples, both mutations, Rif(R) and Spo(-), were induced and their rates increased by several orders of magnitude. Extraterrestrial solar UV radiation (>110?nm) as well as simulated martian UV radiation (>200?nm) led to the most pronounced increase (up to nearly 4 orders of magnitude); however, mutations were also induced in flight samples shielded from insolation, which were exposed to the same conditions except solar irradiation. Nucleotide sequencing located the Rif(R) mutations in the rpoB gene encoding the ?-subunit of RNA polymerase. Mutations isolated from flight and parallel mission ground reference (MGR) samples were exclusively localized to Cluster I. The 21 Rif(R) mutations isolated from the flight experiment showed all a C to T transition and were all localized to one hotspot: H482Y. In mutants isolated from the MGR, the spectrum was wider with predicted amino acid changes at residues Q469K/L/R, H482D/P/R/Y, and S487L. The data show the unique mutagenic power of space and martian surface conditions as a consequence of DNA injuries induced by solar UV radiation and space vacuum or the low pressure of Mars. PMID:22680692

Moeller, Ralf; Reitz, Günther; Nicholson The Protect Team, Wayne L; Horneck, Gerda

2012-05-01

360

Pulmonary nodules in workers exposed to urban stressor  

SciTech Connect

By multilayer spiral low-dose computed tomography (LD-CT) of the chest this study assesses the early detection of lung lesions on a sample of 100 traffic policemen of a big Italian city professionally exposed to urban pollutants and 100 controls non-occupationally exposed to urban pollutants matched by sex, age, length of service and cigarette smoking habit. Exposure to urban pollutants in traffic policemen was characterized using the annual average concentrations of PM{sub 10}, NO{sub 2} and benzene in the period 1998-2008 measured by fixed monitoring stations located in different areas of the city. A significant and increasing number of suspicious lung nodules with diameters between 5 and 10 mm was observed: in traffic policemen (including smokers and non-smokers) vs. controls (including smokers and non-smokers); in total smokers (including traffic policemen and controls) vs. total non-smokers (traffic policemen and controls); in smoker traffic policemen vs. smoker controls and vs. non-smoker traffic policemen; in non-smoker traffic policemen vs. non-smoker controls. The RR of finding cases with at least one lung nodule with diameters between 5 and 10 mm in traffic policemen (including smokers and non-smokers) compared to controls (including smokers and non-smokers) is 1.94 (CI 1.13-3.31); in total smokers vs. non-smokers the RR is 1.96 (CI 1.20-3.19). The comparison between the interaction exposure and smoking shows an increase in smoker traffic policemen than in smoker controls (RR=2.14; CI 1.02-4.52). The RR for smoker traffic policemen was higher than in non-smoker traffic policemen (RR=2.09; CI 1.19-3.66). The results of our study show that: (1) while smoker workers have a higher risk for developing solid suspicious lung nodules, the simple routinely exposure to urban pollutants is unable to produce the same kind of increased risk; (2) the interaction of smoking and exposure to urban pollutants greatly increases the risk for the development of solid suspicious lung nodules. In conclusion, the use of chest LD-CT in workers at risk helps identify suspicious solid lung nodules at early stage.

Sancini, A. [University of Rome 'Sapienza', Department of Occupational Medicine, Viale Regina Elena 336, 00161 Rome (Italy)] [University of Rome 'Sapienza', Department of Occupational Medicine, Viale Regina Elena 336, 00161 Rome (Italy); Fioravanti, M. [University of Rome 'Sapienza', Department of Psychiatric Science and Psychological Medicine, Piazzale Aldo Moro 5, 00185 Rome (Italy)] [University of Rome 'Sapienza', Department of Psychiatric Science and Psychological Medicine, Piazzale Aldo Moro 5, 00185 Rome (Italy); Ciarrocca, M.; Palermo, P.; Fiaschetti, M.; Schifano, M.P. [University of Rome 'Sapienza', Department of Occupational Medicine, Viale Regina Elena 336, 00161 Rome (Italy)] [University of Rome 'Sapienza', Department of Occupational Medicine, Viale Regina Elena 336, 00161 Rome (Italy); Tomei, G. [University of Rome 'Sapienza', Department of Psychiatric Science and Psychological Medicine, Piazzale Aldo Moro 5, 00185 Rome (Italy)] [University of Rome 'Sapienza', Department of Psychiatric Science and Psychological Medicine, Piazzale Aldo Moro 5, 00185 Rome (Italy); Tomei, F., E-mail: francesco.tomei@uniroma1.it [University of Rome 'Sapienza', Department of Occupational Medicine, Viale Regina Elena 336, 00161 Rome (Italy)

2010-07-15

361

Cancer mortality among electric utility workers exposed to polychlorinated biphenyls.  

PubMed Central

OBJECTIVES: To assess whether excess mortality from cancer, malignant melanoma of the skin, and cancers of the brain and liver in particular, is associated with long term occupational exposure to polychlorinated biphenyls (PCBs). METHODS: An epidemiological study of mortality was conducted among 138,905 men employed for at least six months between 1950 and 1986 at five electrical power companies in the United States. Exposures were assessed by panels composed of workers, hygienists, and managers at each company, who considered tasks performed by workers in 28 job categories and estimated weekly exposures in hours for each job. Poisson regression was used to examine mortality in relation to exposure to electrical insulating fluids containing PCBs, controlling for demographic and occupational factors. RESULTS: Neither all cause nor total cancer mortality was related to cumulative exposure to PCB insulating fluids. Mortality from malignant melanoma increased with exposure; rate ratios (RRs) relative to unexposed men for melanoma were 1.23 (95% confidence interval (95% CI) 0.56 to 2.52), 1.71 (0.68 to 4.28) and 1.93 (0.52 to 7.14) for men with < 2000, > 2000-10,000, and > 10,000 hours of cumulative exposure to PCB insulating fluids, respectively, without consideration of latency. Lagging exposure by 20 years yielded RRs of 1.29 (0.76 to 2.18), 2.56 (1.09 to 5.97), and 4.81 (1.49 to 15.50) for the same exposure levels. Mortality from brain cancer was modestly increased among men with < 2000 hours (RR 1.61, 95% CI 0.86 to 3.01) and > 2000-10,000 hours exposure (RR 1.79, 95% CI 0.81 to 3.95), but there were no deaths from brain cancer among the most highly exposed men. A lag of five years yielded slightly increased RRs. Mortality from liver cancer was not associated with exposure to PCB insulating fluids. CONCLUSIONS: This study was larger and provided more detailed information on exposure than past investigations of workers exposed to PCBs. The results suggest that PCBs cause cancer, with malignant melanoma being of particular concern in this industry. PMID:9404319

Loomis, D; Browning, S R; Schenck, A P; Gregory, E; Savitz, D A

1997-01-01

362

Multipili attachment of bacteria with helixlike pili exposed to stress  

NASA Astrophysics Data System (ADS)

A number of biomechanical properties of various types of pili expressed by Escherichia coli, predominantly their force-versus-elongation behavior, have previously been assessed in detail on a single pilus level. In vivo, however, bacteria bind in general to host cells by a multitude of pili, which presumably provides them with adhesion properties that differs from those of single pili. Based upon the previously assessed biomechanical properties of individual pili, this work presents a theoretical analysis of the adhesion properties of multipili-attaching bacteria expressing helixlike pili exposed to an external force. Expressions for the adhesion lifetime of dual- and multipili-attaching bacteria are derived and their validity is verified by Monte Carlo simulations. It is demonstrated that the adhesion lifetime of a multipili-binding bacterium depends to a large degree on the cooperativity of the attaching pili, which, in turn, depends strongly on their internal biomechanical properties, in particular their helixlike structure and its ability to elongate, which, in turn, depends on the intrinsic properties of the bonds, e.g., their lengths and activation energies. It is shown, for example, that a decrease in the length of a layer-to-layer bond in the rod of P pili, expressed by E. coli, by 50% leads to a decrease in the adhesion lifetime of a bacterium attaching by ten pili and exposed to a force of 500 pN by three orders of magnitude. The results indicate moreover that the intrinsic properties of the rod for this particular type of pili are optimized for multipili attachment under a broad range of external forces and presumably also to its in vivo environment. For example, P pili seems to be optimized to withstand a force exposure during ~3 s, which correspond to the time it takes for a bolus to pass a bacterium attached to the ureteral wall. Even though the results presented in this work apply quantitatively to one type of pilus, they are assumed to apply qualitatively to all helixlike pili systems expressing slip bonds.

Björnham, Oscar; Axner, Ove

2009-06-01

363

9 CFR 430.4 - Control of Listeria monocytogenes in post-lethality exposed ready-to-eat products.  

... Control of Listeria monocytogenes in post-lethality exposed ready-to-eat products... Control of Listeria monocytogenes in post-lethality exposed ready-to-eat products...hazard that an establishment producing post-lethality exposed RTE products...

2014-01-01

364

9 CFR 430.4 - Control of Listeria monocytogenes in post-lethality exposed ready-to-eat products.  

Code of Federal Regulations, 2010 CFR

... Control of Listeria monocytogenes in post-lethality exposed ready-to-eat products... Control of Listeria monocytogenes in post-lethality exposed ready-to-eat products...hazard that an establishment producing post-lethality exposed RTE products...

2010-01-01

365

9 CFR 430.4 - Control of Listeria monocytogenes in post-lethality exposed ready-to-eat products.  

Code of Federal Regulations, 2011 CFR

... Control of Listeria monocytogenes in post-lethality exposed ready-to-eat products... Control of Listeria monocytogenes in post-lethality exposed ready-to-eat products...hazard that an establishment producing post-lethality exposed RTE products...

2011-01-01

366

Security Conference in Europe Exposes Rifts between US, Allies  

NSDL National Science Digital Library

A high-level security conference in Munich this weekend exposed rifts between the US and its European allies on the issues of a US missile defense system and the deployment of a "rapid reaction" European Union force. The US missile defense system took center stage over the weekend as Secretary of Defense Donald Rumsfeld announced the Bush administration's plan to go ahead with development and deployment, unilaterally if necessary. Deliberately dropping "national" or "US" from his references to the system, Rumsfeld offered to develop it with European allies and extend its protection to their countries as well. Nonetheless, the European response was guarded and cautiously negative. German Chancellor Gerhard Schroeder warned the US against "overly hasty and early determinations" about deploying missile defenses. The reaction of Russia was more pointed, referring to the possible development of a new arms race that could extend even into outer space (the Bush administration is considering a laser defense system) and the system's violation of the 1972 Anti-Ballistic Missile Treaty. Rumsfeld dismissed European fears as unfounded and suggested that the relationship with Russia needed to be renegotiated on the ground of current threats, rather than outdated cold war assumptions. In the meantime, talks at the conference also revealed some US concern over current European Union plans to develop a "rapid reaction" force that could operate independently of NATO. Turkey's opposition to such a force, combined with the US's concerns, may help to ultimately kill the project.

Charbonneau, David D.

2001-01-01

367

Radiological survey of men exposed to asbestos in naval dockyards  

PubMed Central

Harries, P. G., Mackenzie, F. A. F., Sheers, G., Kemp, J. H., Oliver, T. P., and Wright, D. S. (1972).Brit. J. industr. Med.,29, 274-279. Radiological survey of men exposed to asbestos in naval dockyards. Asbestos related abnormalities were found in 3% of a 10% sample population in radiological surveys of the naval dockyards at Portsmouth, Chatham, and Rosyth. The prevalence of these abnormalities was related to the type of occupation and duration of exposure to asbestos. The results confirm the findings of an earlier survey at Devonport dockyard. No association between smoking, or the amount smoked, and the incidence of parenchymal or pleural disease due to asbestos was detected. Pleural abnormalities were found 10 times more frequently than parenchymal disease, and concern is felt over the uncertainty of the prognosis in men with pleural abnormalities, especially as 37 men have developed pleural mesothelioma at Devonport since 1965. More work is required to establish the true significance of pleural abnormalities caused by asbestos and to explore possible methods of treatment. PMID:5044599

Harries, P. G.; Mackenzie, F. A. F.; Sheers, G.; Kemp, J. H.; Oliver, T. P.; Wright, D. S.

1972-01-01

368

Identifying redundancy and exposing provenance in crowdsourced data analysis.  

PubMed

We present a system that lets analysts use paid crowd workers to explore data sets and helps analysts interactively examine and build upon workers' insights. We take advantage of the fact that, for many types of data, independent crowd workers can readily perform basic analysis tasks like examining views and generating explanations for trends and patterns. However, workers operating in parallel can often generate redundant explanations. Moreover, because workers have different competencies and domain knowledge, some responses are likely to be more plausible than others. To efficiently utilize the crowd's work, analysts must be able to quickly identify and consolidate redundant responses and determine which explanations are the most plausible. In this paper, we demonstrate several crowd-assisted techniques to help analysts make better use of crowdsourced explanations: (1) We explore crowd-assisted strategies that utilize multiple workers to detect redundant explanations. We introduce color clustering with representative selection--a strategy in which multiple workers cluster explanations and we automatically select the most-representative result--and show that it generates clusterings that are as good as those produced by experts. (2) We capture explanation provenance by introducing highlighting tasks and capturing workers' browsing behavior via an embedded web browser, and refine that provenance information via source-review tasks. We expose this information in an explanation-management interface that allows analysts to interactively filter and sort responses, select the most plausible explanations, and decide which to explore further. PMID:24051786

Willett, Wesley; Ginosar, Shiry; Steinitz, Avital; Hartmann, Björn; Agrawala, Maneesh

2013-12-01

369

Lung injury in mice and rats acutely exposed to beryllium  

SciTech Connect

The effect of lung injury, in rats and mice, exposed to an aerosol of beryllium sulfate (BE) for one hour, through nose-only inhalation, was evaluated by the methods of bronchoalveolar lavage (BAL) and lung cell kinetics. The BAL in rats, sacrificed over a 21 day period following exposure, showed lactate dehydrogenase (LDH) and alkaline phosphatase (Alk Pase) activities as the most sensitive indicators of lung damage. LDH activity peaked at day 8 while Alk Pase activity peaked at day 5, both being 30 times greater than comparable control values. Acid phosphatase activity and albumin levels were also increased, but not to the same extent as LDH and Alk Pase. The BAL of mice showed LDH activity as the most sensitive indicator of lung damage, with a maximum response 3 times greater than controls at day 5. In another series of experiments, animals were treated with three agents capable of inducing fibrosis: beryllium sulfate, bleomycin, and butylated hydroxytoluene (BHT). Cy A completely inhibited the fibrogenic effects of BHT in mice, as measured through total lung hydroxyproline content. Bleomycin-induced fibrosis was significantly reduced by Cy A treatment in rats, but showed no effect in mice. Additionally, the effect of iron salt administration to rats decreased the intravenous LD/sub 50/ dose, and significantly reduced the inhalation toxicity, of beryllium sulfate. The protective mechanism of iron salt administration, through the induction of ferritin synthesis, is postulated.

Sendelbach, L.E. Jr.

1985-01-01

370

The efficiency of photovoltaic cells exposed to pulsed laser light  

NASA Technical Reports Server (NTRS)

Future space missions may use laser power beaming systems with a free electron laser (FEL) to transmit light to a photovoltaic array receiver. To investigate the efficiency of solar cells with pulsed laser light, several types of GaAs, Si, CuInSe2, and GaSb cells were tested with the simulated pulse format of the induction and radio frequency (RF) FEL. The induction pulse format was simulated with an 800-watt average power copper vapor laser and the RF format with a frequency-doubled mode-locked Nd:YAG laser. Averaged current vs bias voltage measurements for each cell were taken at various optical power levels and the efficiency measured at the maximum power point. Experimental results show that the conversion efficiency for the cells tested is highly dependent on cell minority carrier lifetime, the width and frequency of the pulses, load impedance, and the average incident power. Three main effects were found to decrease the efficiency of solar cells exposed to simulated FEL illumination: cell series resistance, LC 'ringing', and output inductance. Improvements in efficiency were achieved by modifying the frequency response of the cell to match the spectral energy content of the laser pulse with external passive components.

Lowe, R. A.; Landis, G. A.; Jenkins, P.

1993-01-01

371

Heterogeneous ice nucleation of mineral dust particles exposed to ozone  

NASA Astrophysics Data System (ADS)

Deposition and immersion mode ice nucleation studies of kaolinite (Ka) and Arizona Test Dust (ATD) particles exposed to ozone at 430 ppbv, 1.4 and 4.3 ppmv for approximately 2 hours in a stainless steel aerosol tank are presented. The polydisperse particles used have a mode mobility diameter of 800 nm for Ka and 400 nm for ATD. The portable ice nucleation chamber (PINC) and immersion chamber (IMCA-ZINC) were used to study deposition and immersion mode ice nucleation respectively. Both instruments sampled through a particle impactor with a diameter cut-off size of 1 ?m. Preliminary results indicate that ice nucleation can be enhanced or inhibited depending on ozone concentration used for the ageing process with higher concentrations suppressing ice nucleation in both immersion and deposition modes. Additionally, Ka and ATD respond differently to the ageing process and to the different modes of ice nucleation. Ozone surface coverage and initial uptake coefficients are presented for the low exposure studies to explain the ice nucleation behavior observed. Ice Active Surface Site Densities (IASSD) are presented as a means of comparison and parameterization of the data to predict potential atmospheric ice nuclei (IN) concentrations.

Kanji, Zamin A.; Welti, André; Chou, Cédric; Stetzer, Olaf; Lohmann, Ulrike

2013-05-01

372

Temperature and adrenocortical responses in rhesus monkeys exposed to microwaves  

SciTech Connect

To determine if the endocrine response to microwave exposure was similar in a primate to that reported for other animals, rectal temperature and plasma levels of cortisol, thyroxine (T4), and growth hormone (GH) were measured in rhesus monkeys exposed to 1.29-GHz microwave radiation. Exposures were carried out under far-field conditions with the monkey restrained in a chair. Incident power densities of 0, 20, 28, and 38 mW/sq cm were used, with corresponding specific absorption rates of 0, 2.1, 3.0, and 4.1 W/kg. Blood samples were taken hourly via an indwelling jugular venous catheter over a 24-h period before, during, and after an 8-h exposure. Rectal temperature increased an average of 0.5, 0.7, and 1.7 C for the three intensities used. No changes in T4 or GH were observed. Cortisol levels were increased during exposure to 38 mW/sq cm. It was concluded that the temperature and adrenocortical responses to microwave exposure of the rhesus monkey are similar to the corresponding responses of other animals.

Lotz, W.G.; Podgorski, R.P.

1982-12-01

373

Immunomodulatory effects of nanocurcumin in arsenic-exposed rats.  

PubMed

We evaluated whether the nanoformulation of curcumin could be more effective than free curcumin against arsenic-induced immune dysfunction in rats. Curcumin was encapsulated in polylactic-co-glycolic acid (PLGA). Nanocurcumin (CUR-NP) exhibited a spherical shape with the mean particle size of 130.8 nm. Rats were randomly divided into five groups of six each. Group I was kept as the control. In Group II, rats were exposed to sodium arsenite (25 ppm) daily through drinking water for 42 days. Groups III, IV and V were treated with arsenic as in Group II, however, they were administered with nanoparticle, curcumin (100 mg/kg bw) and CUR-NP (100 mg/kg bw), respectively, by oral gavage during the last 14 days of arsenic exposure. At term, serum and spleen were collected. Immune dysfunction was evaluated by assessing cellular and humoral immunities. Arsenic significantly decreased the splenic lymphocyte proliferation in response to the antigen -- Keyhole Limpet Hemocyanin (KLH) and mitogen -- concanavalin-A. Arsenic reduced both the delayed type hypersensitivity response and secondary antibody (IgG) response to KLH. It also reduced the lipopolysaccharide-stimulated nitric oxide production in splenic lymphocytes. Free curcumin and CUR-NP treatment significantly attenuated these arsenic-mediated effects. However, the magnitude of the effects indicates that CUR-NP has better ameliorative potential than free curcumin at the equivalent dose level. PMID:23747587

Sankar, Palanisamy; Telang, Avinash Gopal; Suresh, Subramaniyam; Kesavan, Manickam; Kannan, Kandasamy; Kalaivanan, Ramya; Sarkar, Souvendra Nath

2013-09-01

374

Peripheral blood effects in benzene-exposed workers.  

PubMed

The hematotoxic effects of benzene exposure may be important in the occurrence of subsequent health effects. We sought to provide further information on peripheral blood effects by studying 928 workers in five factories in and around Shanghai, China exposed to a wide range of benzene concentrations. Specifically, we sought to investigate which blood indices are more strongly related to benzene exposure and which concentration levels of benzene result in peripheral blood changes. Lifestyle habits and demographic information was obtained via questionnaire, and potentially important genetic influences were determined by assessing single nucleotide polymorphisms in four genes (NQO1, MPO, CYP2E1, GSTT1). Weekly benzene exposure estimated from individual monitoring results ranged from 0.07 to 872 mg/m(3) with a median value of 7.4 mg/m(3). Twelve peripheral blood indices were examined. Stronger effects on peripheral blood were seen for red cell indices such as anemia and macrocytosis, albeit at higher (>10 ppm) exposure levels. The most sensitive parameters to benzene appeared to be neutrophils and the mean platelet volume (MPV), where effects were seen for benzene air concentrations of 7.8-8.2 ppm. Toluene exposure is a potential confounder for some peripheral blood effects, pointing to the need to scrutinize levels of both compounds in the occupational environment. PMID:20034484

Robert Schnatter, A; Kerzic, Patrick J; Zhou, Yimei; Chen, Min; Nicolich, Mark J; Lavelle, Karlene; Armstrong, Thomas W; Bird, Michael G; Lin, Lv; Fu, Hua; Irons, Richard D

2010-03-19

375

Toxicogenomic profiling of chemically exposed humans in risk assessment  

PubMed Central

Gene-environment interactions contribute to complex disease development. The environmental contribution, in particular low-level and prevalent environmental exposures, may constitute much of the risk and contribute substantially to disease. Systematic risk evaluation of the majority of human chemical exposures, has not been conducted and is a goal of regulatory agencies in the U.S. and worldwide. With the recent recognition that toxicological approaches more predictive of effects in humans are required for risk assessment, in vitro human cell line data as well as animal data are being used to identify toxicity mechanisms that can be translated into biomarkers relevant to human exposure studies. In this review, we discuss how data from toxicogenomic studies of exposed human populations can inform risk assessment, by generating biomarkers of exposure, early effect, and/or susceptibility, elucidating mechanisms of action underlying exposure-related disease, and detecting response at low doses. Good experimental design incorporating precise, individual exposure measurements, phenotypic anchors (pre-disease or traditional toxicological markers), and a range of relevant exposure levels, is necessary. Further, toxicogenomic studies need to be designed with sufficient power to detect true effects of the exposure. As more studies are performed and incorporated into databases such as the Comparative Toxicogenomics Database (CTD) and Chemical Effects in Biological Systems (CEBS), data can be mined for classification of newly tested chemicals (hazard identification), and, for investigating the dose-response, inter-relationship among, genes, environment and disease in a systems biology approach (risk characterization). PMID:20382258

McHale, Cliona M.; Zhang, Luoping; Hubbard, Alan E.; Smith, Martyn T.

2010-01-01

376

Cancer mortality among petroleum-solvent-exposed Oklahoma dry cleaners  

SciTech Connect

This study assesses the solvent specific influence on the proportionate mortality occurring among white males with exposures to petroleum solvents, averaging 10.5 years, and were without known exposure to synthetic solvents. No excess in overall cancer mortality, or in any major noncancer cause of death was found. The proportionate mortality ration (PMR) for All malignant neoplasms was 1.04 and was independent of latency and years of exposure. No excess in overall cancer deaths was found to occur in cohort members dying before age 65. A significant excess in respiratory system cancer was detected, with all excesses occurring among those who died at age 65 and older. No relationship was noted to years of latency or years of exposure. A PMR of 1.96 for pancreatic cancer was noted with three of nine deaths occurring among men younger than age 65. Consistent elevations if PMRs were seen for all categories of duration of exposure greater than 5-9 years. No pancreatic cancer deaths occurred with less than 20 years of latency. Excesses found for kidney cancer among the entire cohort were lost when only petroleum solvent exposed white males were analyzed. The power to detect an excess or deficit in overall or site-specific cancer deaths was adequate at relative risk of four or less for most cancer sites of interest.

Petrone, R.L.

1987-01-01

377

Immunological studies on mice exposed subacutely to methyl isocyanate  

SciTech Connect

The immunotoxicity of methyl isocyanate (MIC) was evaluated in female B6C3F1 mice exposed via inhalation to 0, 1, or 3 ppm for 6 hr per day on 4 consecutive days. The antibody response to sheep erythrocytes and natural killer cell activity were found to be unaffected by MIC exposure. Although lymphoproliferative responses to mitogens were moderately suppressed by MIC, the differences were not statistically significant. The response of splenic lymphocytes to allogeneic leukocytes in a mixed leukocyte response (MLR) was suppressed in a dose-related fashion and was significantly different from the control response at the 3 ppm level. This effect was thought to be secondary and a result of general toxicity rather than a direct effect of MIC on the immune system. Furthermore, resistance to the infectious agents Listeria monocytogenes, mouse malaria parasite, and influenza virus, or to transplantable tumor cells was not compromised by MIC exposure. Thus, the immune system does not appear to be a primary target for MIC toxicity.

Tucker, A.N.; Bucher, J.R.; Germolec, D.R.; Silver, M.T.; Vore, S.J.; Luster, M.I.

1987-06-01

378

Coating concrete secondary containment structures exposed to agrichemicals  

SciTech Connect

Concrete has traditionally been the material of choice for building secondary containment structures because it is relatively inexpensive and has structural properties which make it ideal for supporting the loads of vehicles and large tanks. However, concrete`s chemical properties make it susceptible to corrosion by some common fertilizers. Though fairly impervious to water movement, concrete is easily penetrated by vapors and solvents. It is also prone to cracking. For these reasons, the Environmental Protection Agency (EPA) believes that concrete alone may not provide an effective barrier to pesticide movement and has proposed that concrete in pesticide secondary containment structures be sealed or coated to reduce its permeability. Some state secondary containment regulations require that concrete exposed to fertilizers and pesticides be sealed or protected with a coating. Lacking guidelines, some retailers have used penetrating sealants to satisfy the law, even though these products provide little protection from chemical attack nor do they prevent pesticide egress. Other retailers who have applied thick film coatings which were properly selected have had disastrous results because the application was poorly done. Consequently, much skepticism exists regarding the performance and benefit of protective coatings.

Broder, M.F.; Nguyen, D.T.

1995-06-01

379

Exposing Middle School Students to Remote Sensing in Alaska  

NASA Astrophysics Data System (ADS)

The need for attracting young minds to scientific research at an early stage is already recognized. Efforts are underway by major organizations to inspire the next generation of scientists. To be effective, there is a need to exploit the potential of the World Wide Web and bring it to a status that printed media have already reached. We find series of theme oriented books for children but websites with such stories are few and scattered. NASA's efforts in generating remote sensing based web stories such as the 'Adventures of Amelia the Pigeon' and 'Echo the Bat' are very good examples and starting points for generating more theme based material for children. 'Alaska: A Bird's Eye View' is a web-based story, specifically designed for grade 5-8 students. The story that is told by a Canada Goose exposes children to the truths of the remote State of Alaska and to the potential of satellite remote sensing. Examples on use remote sensing for monitoring volcanoes and sea ice edge dynamics are related to children in simple and effective ways. The topic of global climate change and its effect on marine animals has also been introduced to children.

Prakash, A.

2003-12-01

380

Reproductive effects in birds exposed to pesticides and industrial chemicals  

SciTech Connect

Environmental contamination by agricultural chemicals and industrial waste disposal results in adverse effects on reproduction of exposed birds. The diversity of pollutants results in physiological effects at several levels, including direct effects on breeding adults as well as developmental effects on embryos. The effects on embryos include mortality or reduced hatchability, failure of chicks to thrive (wasting syndrome), and teratological effects producing skeletal abnormalities and impaired differentiation of the reproductive and nervous systems through mechanisms of hormonal mimicking of estrogens. The range of chemical effects on adult birds covers acute mortality, sublethal stress, reduced fertility, suppression of egg formation, eggshell thinning, and impaired incubation and chick rearing behaviors. The types of pollutants shown to cause reproductive effects include organochlorine pesticides and industrial pollutants, organophosphate pesticides, petroleum hydrocarbons, heavy metals, and in a fewer number of reports, herbicides, and fungicides. o,p`-DDT, polychlorinated biphenyls (PCBs), and mixtures of organochlorines have been identified as environmental estrogens affecting populations of gulls breeding in polluted {open_quotes}hot spots{close_quotes} in southern California, the Great Lakes, and Puget Sound. Estrogenic organochlorines represent an important class of toxicants to birds because differentiation of the avian reproductive system is estrogen dependent. 85 refs.

Fry, D.M. [Univ. of California, Davis, CA (United States)

1995-10-01

381

Model for a dune field with exposed water table  

E-print Network

Aeolian transport in coastal areas can be significantly affected by the presence of an exposed water table. In some dune fields, such as in Len\\c{c}\\'ois Maranhenses, northeastern Brazil, the water table oscillates in response to seasonal changes of rainfall and rates of evapotranspiration, rising above the ground during the wet season and sinking below in the dry period. A quantitative understanding of dune mobility in an environment with varying groundwater level is essential for coastal management as well as for the study of long-term evolution of many dune fields. Here we apply a model for aeolian dunes to study the genesis of coastal dune fields in presence of an oscillating water table. We find that the morphology of the field depends on the time cycle, $T_{\\mathrm{w}}$, of the water table and the maximum height, $H_{\\mathrm{w}}$, of its oscillation. Our calculations show that long chains of barchanoids alternating with interdune ponds such as found at Len\\c{c}\\'ois Maranhenses arise when $T_{\\mathrm{w}}$ is of the order of the dune turnover time, whereas $H_{\\mathrm{w}}$ dictates the growth rate of dune height with distance downwind. We reproduce quantitatively the morphology and size of dunes at Len\\c{c}\\'ois Maranhenses, as well as the total relative area between dunes.

Marco Cesar M. de M. Luna; Eric J. R. Parteli; Hans J. Herrmann

2011-09-01

382

Environmental change exposes beneficial epistatic interactions in a catalytic RNA.  

PubMed

Natural selection drives populations of individuals towards local peaks in a fitness landscape. These peaks are created by the interactions between individual mutations. Fitness landscapes may change as an environment changes. In a previous contribution, we discovered a variant of the Azoarcus group I ribozyme that represents a local peak in the RNA fitness landscape. The genotype at this peak is distinguished from the wild-type by four point mutations. We here report ribozyme fitness data derived from constructing all possible combinations of these point mutations. We find that these mutations interact epistatically. Importantly, we show that these epistatic interactions change qualitatively in the three different environments that we studied. We find examples where the relative fitness of a ribozyme can change from neutral or negative in one environment, to positive in another. We also show that the fitness effect of a specific GC-AU base pair switch is dependent on both the environment and the genetic context. Moreover, the mutations that we study improve activity at the cost of decreased structural stability. Environmental change is ubiquitous in nature. Our results suggest that such change can facilitate adaptive evolution by exposing new peaks of a fitness landscape. They highlight a prominent role for genotype-environment interactions in doing so. PMID:22719036

Hayden, Eric J; Wagner, Andreas

2012-09-01

383

Environmental change exposes beneficial epistatic interactions in a catalytic RNA  

PubMed Central

Natural selection drives populations of individuals towards local peaks in a fitness landscape. These peaks are created by the interactions between individual mutations. Fitness landscapes may change as an environment changes. In a previous contribution, we discovered a variant of the Azoarcus group I ribozyme that represents a local peak in the RNA fitness landscape. The genotype at this peak is distinguished from the wild-type by four point mutations. We here report ribozyme fitness data derived from constructing all possible combinations of these point mutations. We find that these mutations interact epistatically. Importantly, we show that these epistatic interactions change qualitatively in the three different environments that we studied. We find examples where the relative fitness of a ribozyme can change from neutral or negative in one environment, to positive in another. We also show that the fitness effect of a specific GC–AU base pair switch is dependent on both the environment and the genetic context. Moreover, the mutations that we study improve activity at the cost of decreased structural stability. Environmental change is ubiquitous in nature. Our results suggest that such change can facilitate adaptive evolution by exposing new peaks of a fitness landscape. They highlight a prominent role for genotype–environment interactions in doing so. PMID:22719036

Hayden, Eric J.; Wagner, Andreas

2012-01-01

384

Phospholipid peroxidation in tumor promoter-exposed mouse skin.  

PubMed

We have investigated lipid peroxidation in the skin of CD1 mice following single or repeated topical applications of the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). A substantial accumulation of hydroxyphospholipids, to levels 3-5 times control values, followed exposure to two or more TPA treatments (24-72 h intervals), whereas single applications were ineffective. Sodium borohydride reduction increased the yield of product by approximately 50%, suggesting the additional presence of phospholipid hydroperoxides in the oxidized lipids. Straight phase HPLC analysis of the constituent hydroxy fatty acids, followed by gas chromatography/mass spectrometry, revealed that oxidized derivatives of linoleic acid, including 9- and 13-hydroxyoctadecadienoic acids (9- and 13-HODE), were the primary products. Stereochemical analysis showed ratios of S to R stereoisomers of 1.3 for 13-HODE and 1.27 for 9-HODE, which implied that TPA-induced peroxidation was primarily due to free radical oxidation, although a partial contribution of enzyme (lipoxygenase) activity is possible. The TPA-induced peroxidation was greater in the epidermis than in the dermis. Pre-exposure of mouse skin to the anti-inflammatory agent fluocinolone acetonide, antioxidants and enzyme (phospholipase A2 and lipoxygenase) inhibitors lowered the peroxidation response to subsequent exposure to TPA. Phospholipid peroxidation products may be useful markers of oxygen radical production in TPA-exposed mouse skin with possible relevance to tumor promotion. PMID:8001259

Beckman, J K; Bagheri, F; Ji, C; Blair, I A; Marnett, L J

1994-12-01

385

Antenatal Atazanavir: A Retrospective Analysis of Pregnancies Exposed to Atazanavir  

PubMed Central

Introduction. There are few data regarding the tolerability, safety, or efficacy of antenatal atazanavir. We report our clinical experience of atazanavir use in pregnancy. Methods. A retrospective medical records review of atazanavir-exposed pregnancies in 12 London centres between 2004 and 2010. Results. There were 145 pregnancies in 135 women: 89 conceived whilst taking atazanavir-based combination antiretroviral therapy (cART), “preconception” atazanavir exposure; 27 started atazanavir-based cART as “first-line” during the pregnancy; and 29 “switched” to an atazanavir-based regimen from another cART regimen during pregnancy. Gastrointestinal intolerance requiring atazanavir cessation occurred in five pregnancies. Self-limiting, new-onset transaminitis was most common in first-line use, occurring in 11.0%. Atazanavir was commenced in five switch pregnancies in the presence of transaminitis, two of which discontinued atazanavir with persistent transaminitis. HIV-VL < 50 copies/mL was achieved in 89.3% preconception, 56.5% first-line, and 72.0% switch exposures. Singleton preterm delivery (<37 weeks) occurred in 11.7% preconception, 9.1% first-line, and 7.7% switch exposures. Four infants required phototherapy. There was one mother-to-child transmission in a poorly adherent woman. Conclusions. These data suggest that atazanavir is well tolerated and can be safely prescribed as a component of combination antiretroviral therapy in pregnancy. PMID:25328370

Samuel, Miriam; Bradshaw, Daniel; Perry, Melissa; Chan, Sum Yee; Dhairyawan, Rageshri; Byrne, Laura; Smith, Katherine; Zhou, Judith; Short, Charlotte Eve; Naftalin, Claire; Offodile, Ngozi; Mandalia, Sundhiya; Roedling, Sherie; Shah, Rimi; Brook, Gary; Poulton, Mary; Rodgers, Mette; Sarner, Liat; Noble, Heather; Hay, Philip; Anderson, Jane; Natha, Macky; Hawkins, David; Taylor, Graham; de Ruiter, Annemiek

2014-01-01

386

WASTE CHARACTERIZATION OF POLYMERIC COMPONENTS EXPOSED TO TRITIUM GAS  

SciTech Connect

A recent independent review led to uncertainty about the technical basis for characterizing the residual amount of tritium in polymer components used in the Savannah River Site Tritium Facilities that are sent for waste disposal. A review of a paper published in the open literature firmly establishes the basis of the currently used characterization, 10 Ci/cc. Information provided in that paper about exposure experiments performed at the DOE Mound Laboratory allows the calculation of the currently used characterization. These experiments involved exposure of high density polyethylene (HD-PE) to initially 1 atm tritium gas. In addition, a review of recent research at the Savannah River Site not only further substantiates this characterization, but also establishes its use for ultra-high molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, a trade name is Teflon{reg_sign}), and Vespel{reg_sign} polyimide. 10 Ci/cc tritium is a representative characterization for any type of polymer components exposed at ambient temperature and at approximately 1 atm. tritium gas.

Clark, E

2008-02-15

387

Measuring exposed magnetic fields of welders in working time.  

PubMed

The assessment of the occupational electromagnetic field exposure of welders is of great importance, especially in shielded-arc welding, which uses relatively high electric currents of up to several hundred amperes. In the present study, we measured the magnetic field exposure level of welders in the course of working. A 3-axis Hall magnetometer was attached to a subject's wrist in order to place the sensor probe at the closest position to the magnetic source (a cable from the current source). Data was acquired every 5 s from the beginning of the work time. The maximum exposed field was 0.35-3.35 mT (Mean ± SD: 1.55 ± 0.93 mT, N=17) and the average value per day was 0.04-0.12 mT (Mean ± SD: 0.07 ± 0.02 mT, N=17). We also conducted a finite element method-based analysis of human hand tissue for the electromagnetic field dosimetry. In addition, the magnetic field associated with grinders, an air hammer, and a drill using electromagnetic anchorage were measured; however, the magnetic fields were much lower than those generated in the welding process. These results agreed well with the results of the electromagnetic field dosimetry (1.49 mT at the wrist position), and the calculated eddy current (4.28 mA/m(2)) was much lower than the well-known guideline thresholds for electrical nerve or muscular stimulation. PMID:21670555

Yamaguchi-Sekino, Sachiko; Ojima, Jun; Sekino, Masaki; Hojo, Minoru; Saito, Hiroyuki; Okuno, Tsutomu

2011-01-01

388

Intraspecific diet shift in Talitrus saltator inhabiting exposed sandy beaches  

NASA Astrophysics Data System (ADS)

Talitrid amphipods are the most abundant herbivores on exposed sandy beaches. Despite their important role as trophic intermediates between macrophytes and higher levels (i.e. insect and bird) of beach food webs, very little information is available on their feeding patterns. The main aim of this study was to investigate intraspecific differences in the feeding behaviour of Talitrus saltator. We tested the hypotheses that: (1) adult females and males showed different isotope signatures and therefore relied on different sources of food; and (2) patterns of variation of isotope signatures of juveniles differed from those of adult specimens, evidencing a diet shift during the development. We used stable isotope signatures and tested for differences upon the level on the shore, times of the year and beaches experiencing similar morpho-dynamic and environmental conditions. Finally, we investigated the trophic significance of macrophyte detritus in the diet of males, females and juveniles. Results showed that adult males had a more variable diet than females and juveniles (inferred from ? 13C and ? 15N values). Dual-isotope graphs suggested that Sargassum muticum and Cystoseira baccata wrack could be among the main food sources for both juvenile and adult stage.

Olabarria, Celia; Incera, Mónica; Garrido, Josefina; Rodil, Iván F.; Rossi, Francesca

2009-09-01

389

Photoactivation of corticosteroids in UVB-exposed skin.  

PubMed

The photodegradation of flumethasone (FM) and fluocinolone acetonide (FC) was studied in solution and in the pig skin. Both glucocorticosteroids applied to the pig skin were unstable under UVB light. The photoproducts formed in the skin were the lumi-, photolumi- and andro-derivatives for FM, the same found in vitro. Instead, FC hydroperoxide formed in solution was not found in the skin: the reactivity and oxidative ability of this photoproduct towards biological substrates (lipids, proteins) seems the reason of the lack of its detection in the ex vivo model. In fact, it demonstrated to quickly oxidize amino acids and peptides, and to react with BSA both in the dark and under irradiation. Moreover, the presence in the irradiated pig skin of the FC andro-derivative, which usually forms in H-donating environment, seems consistent with the mechanism of Norrish I fragmentation followed by H-abstraction, likely from the surrounding biological substrates. These findings indicate that photoreactivity of these compounds may take place in the skin of patients exposing themselves to sunlight and is a warning about possible skin damage as a result of that. Furthermore, photolability of these drugs in the skin might cause loss of their therapeutic activity. PMID:21324709

Miolo, G; Caffieri, S; Dalzoppo, D; Gallocchio, F; Fasani, E; Beyersbergen van Henegouwen, G M J

2011-04-01

390

Shorebird use of an exposed sandy beach in southern California  

NASA Astrophysics Data System (ADS)

Frequent morning surveys of birds were conducted on 1 km of beach in southern California to investigate shorebird use of an exposed sandy beach. The overall mean abundance (98.6 individuals km -1), estimated biomass (9.6 kg km -1), and species richness (5.5 species km -1) of shorebirds observed were very high for a sandy beach in the temperate zone. Eight species, sanderling ( Calidris alba), semipalmated plover ( Charadrius semipalmatus), marbled godwit ( Limosa fedoa), black-bellied plover ( Pluvialis squatarola), western sandpiper ( Calidris mauri), willet ( Catoptrophorus semipalmatus), surfbird ( Aphriza virgata), and whimbrel ( Numenius phaeopus), occurred in overall mean abundances >1 bird km -1 and accounted for 97% of the abundance and biomass of shorebirds. Sanderlings were the most abundant shorebird every year (64% of individuals and 35% of the biomass). Different species of abundant shorebirds exhibited distinct patterns of use of beach habitat, including fall, spring, and winter peaks in abundance. Temporal variation in shorebird use on seasonal and interannual scales was associated with migration patterns, and also with habitat availability and condition. Seasonal variation in monthly mean abundance and estimated biomass of shorebirds varied over more than an order of magnitude and followed a similar pattern in each year, reaching maxima in the fall or winter (161-280 individuals km -1 and 15.4-23.9 kg km -1) and minima in May or June (3-11 individuals km -1 and 0.8-2.2 kg km -1). A minor peak in shorebird abundance and biomass coinciding with spring migration was observed in April of most years. The number of species of shorebirds observed in individual surveys ranged from 0 to 11 species km -1 and was positively and significantly correlated with abundance. Monthly mean species richness and the total species observed monthly followed similar seasonal patterns, ranging from annual maxima of 7.4-9.1 and 12-17 species km -1 between August and October to minima of 0.8-2.1 and 2-8 species km -1, respectively, during June. In contrast, species turnover was lowest (1.1-1.7) in October and November, and generally highest (2-4) during early summer (June). The amount of sandy intertidal habitat available to shorebirds on the transect was estimated using sand elevations and predicted tide heights. In the fall and winter, the abundance of shorebirds was significantly and positively correlated with tide height, possibly reflecting feeding opportunities and high tide refuge effects during the highest tides. In the spring when sand levels were low, the abundance of shorebirds was negatively correlated with tide height. Prey availability, beach condition and the local availability, and condition of alternative foraging habitats may influence those relationships. Interannual variations in shorebird use and beach condition were observed in the course of the study. During an El Nino Southern Oscillation (ENSO) event (1997-1998), the extent of sandy habitat was greatly reduced and intertidal habitat was mostly converted to rocky substrate. The overall abundance of shorebirds and the mean abundance of some common species (e.g. sanderling) were depressed, and an uncommon species (surfbird, A. virgata) was unusually abundant during the ENSO event. In summary, the results suggest that sandy beaches are important habitat for many species of shorebirds, particularly in areas where alternative coastal foraging habitats, such as coastal wetlands, have become scarce. Understanding the dynamics of and threats to exposed sandy beaches may be increasingly important for shorebird conservation in many coastal regions.

Hubbard, David M.; Dugan, Jenifer E.

2003-10-01

391

[Lacrimation disorders in workers chronically exposed to petroleum derivatives].  

PubMed

Lacrimal fluid plays a very significant role in maintaining proper functions of conjuctivas, cornea and eyelids. The fluid is secreted by the main lacrimal gland and additional glands. It produces the so called preocular lacrimal film. A number of clinical tests, such as Chirmer's tests I and II, break-up-time (BUT), lysozyme, and flow tests are used in quantitative and qualitative analyses, as well as in the determination of the lacrimal film stability. The aim of work was to utilize these in assessing the lacrimal secretion and the lacrimal film stability in workers chronically exposed to petroleum derivatives. Fifty three workers from departments of acetobenzene, benzene and butadiene, phenol and acetone, sewage waters, asphalt oxidas, polyethylene and polypropylene, were eligible for the study (group I). During previous examinations, acquired disorders in colour perception were diagnosed in all the subjects by means of the Mansuella-Fansworth 100-Hue test. The age range was 25 to 56 years, with a mediane of 44.1 years +/- 6.5. Mean duration of employment was 22 years (SD +/- 8.25). The control group (group II) was composed of 28 men aged between 24 and 60 years with a median of 42.7 years +/- 6.3, never employed under conditions of exposure to toxic chemicals. On the right eye of each subject Schirmer's test was performed after instilling into the conjunctival sac 1-2 drops of Alcain solution according to Whitcher. Five min following anesthesia of the conjunctival sac, a standardised belt of blotting-paper with colour dampness markers Vidisic (Dr Mann Pharma GMBH, Germany) was placed in the vicinity of the external angle of the eye. After 5 min the degree of the belt dampness was measured in millimetres. After 30 min the break-up-time test was performed on the left eye. Fluorescein was released to conjunctival sac from a sterile belt of blotting-paper (Haag-Strait Co.). A slit lamp with cobalt filter was used to calculate time (in sec) that elapsed between opening of the lid slit and the first symptom of breaking-up the lacrimal film. The results obtained were presented in the form of arithmetic means and standard deviation values +/- SD. Schirmer's test was 13.40 +/- 7.43 mm in group 1, and 22.54 +/- 8.25 mm in the control group, mean values differed significantly, p < 0.01. Lacrimal film break-up-time was 16.30 +/- 6.19 sec in group 1, and 31.48 +/- 7.96 sec in the control group, mean values differed significantly, p < 0.01. In persons chronically exposed to petroleum derivatives, statistically significant decrease in lacrimal secretion, as well as shortening of lacrimal film break-up-time were found when compared with the control group. PMID:10399714

Go?, R; Jarmak, A; Korzycka, D; Nowicz, B; Zdzieszy?ska, M; Góralczyk, M; Sztarba?a, T; Jurowski, P; Gruntmeyer, M; Kapica, A

1999-01-01

392

Exposing SAMOS Data and Vocabularies within the Semantic Web  

NASA Astrophysics Data System (ADS)

As part of the Ocean Data Interoperability Platform (ODIP), we at the Center for Ocean-Atmospheric Prediction Studies (COAPS) will present the development process for the exposure of quality-controlled data and core vocabularies managed by the Shipboard Automated Meteorological Oceanographic System (SAMOS) initiative using Semantic Web technologies. Participants in the SAMOS initiative collect continuous navigational (position, course, heading, speed), meteorological (winds, pressure, temperature, humidity, radiation), and near-surface oceanographic (sea temperature, salinity) parameters while at sea. One-minute interval observations are packaged and transmitted back to COAPS via daily emails, where they undergo standardized formatting and quality control. The authors will present methods used to expose these daily datasets. The Semantic Web, a vision of the World Wide Web Consortium, focuses on extending the principles of the web from connecting documents to connecting data. The creation of a web of Linked Data that can be used across different applications in a machine-readable way is the ultimate goal. The Resource Description Framework (RDF) is the standard language and format used in the Semantic Web. RDF pages may be queried using the SPARQL Protocol and RDF Query Language (SPARQL). The authors will showcase the development of RDF resources that map SAMOS vocabularies to internationally served vocabularies such as those found in the Natural Environment Research Council (NERC) Vocabulary Server. Each individual SAMOS vocabulary term (data parameter and quality control flag) will be described in an RDF resource page. These RDF resources will define each SAMOS vocabulary term and provide a link to the mapped vocabulary term (or multiple terms) served externally. Along with enhanced retrieval by parameter, time, and location, we will be able to add additional parameters with the confidence that they follow an international standard. The production of RDF resources that link daily SAMOS data to descriptors such as parameters, time and location information, quality assurance reports, and cruise tracks will also be described. The data is housed on a Thematic Real-time Environmental Distributed Data Services (THREDDS) data server, so these RDF resources will enable enhanced retrieval by any of the linked descriptors. We will showcase our collaboration with the Rolling Deck to Repository (R2R) program to develop SPARQL endpoints that distribute SAMOS content. R2R packages and transmits data on a per cruise basis, so an immediate result of the SAMOS exposure will be the narrowing of the gap between expedition type data (e.g. R2R cruises) and SAMOS observatory type data. The authors will present the development of RDF resources that will collectively expose shipboard data, vocabularies, and quality assurance reports in an overall structure which will serve as the basis for a COAPS SPARQL endpoint, enabling easier programmatic access to SAMOS data.

Dockery, Nkemdirim; Elya, Jocelyn; Smith, Shawn

2014-05-01

393

Serum Matrix Metalloproteinase Levels in Patients Exposed to Sulfur Mustard  

PubMed Central

Background: Matrix metalloproteinases (MMPs) are a group of endopeptidases which comprised of various types. These proteolytic enzymes are zinc-dependent and play role in degradation of extracellular matrix (ECM). Various types of cells such as macrophages, fibroblasts, neutrophils, synovial cells and some epithelial cells secrete MMPs. According to previous studies on bronchiolitis and respiratory tract lesions in these patients and unknown pathophysiology mechanism up to date, this cross–sectional study was performed. Objectives: The aim of this study was to compare the serum MMP level in patients with chemical injuries and normal people and also determine the role of these parameters in pulmonary disorders . Materials and Methods: In this cross–sectional study, 25 Iranian patients exposed to the sulfur mustard and 25 unexposed participants as the control group were enrolled. Serum samples were collected from two groups and stored at -70?C until the measurement of MMPs and TIMPs. ELISA kit was used for measurement of MMP and TIMP based on the kit's instruction. For validations in measurement, all samples were analyzed duplicate and in some cases triplicate. Results: The mean level of MMP-9 in serum of chemically-injured group was 1592.42 and this amount in normal group was 679.72 .So there was a significant difference between two groups (P = 0.001) and the mean level of MMP-8 in serum of patients group was 49.10 and in normal group was 35.53. Then there was no significant difference between two groups (P = 0.197). The mean levels of MMP-1 and MMP-2 was not significantly different (P value > 0.05) in the patient and normal groups. And also the mean levels of TIMP-1 and TIMP-2 was not significantly different (P > 0.05) in the patients and normal groups. Conclusions: In summary, serum MMPs in chemically-injured has shown no significant difference with normal people except for the MMP-9. PMID:24829780

Shohrati, Majid; Haji Hosseini, Reza; Esfandiari, Malek Ashtar; Najafian, Nastaran; Najafian, Bita; Golbedagh, Abbas

2014-01-01

394

Distal airway remodeling in rats chronically exposed to ozone  

SciTech Connect

The morphologic changes in the centriacinar region of lungs from 14 rats exposed to either filtered air (8) or 0.95 ppm ozone (6) 8 hours daily for 90 days were examined morphologically and morphometrically. Rats were killed with an overdose of sodium pentobarbital administered intraperitoneally, the trachea cannulated, and thoracic viscera and lungs removed from the chest. Lungs were fixed via intratracheal instillation of a paraformaldehyde/glutaraldehyde cacodylate buffered fixative at 30 cm water pressure. Lung volumes were determined by weight displacement and the left lung lobe was sectioned transversely into 12 slabs. Three slabs from the cranial, middle, and caudal thirds of the lobe were embedded in paraffin and studied by light microscopy. With these sections, we estimated the volume of proximal bronchiole, terminal bronchiole, respiratory bronchiole, and combined alveolar duct/sac within the lung. Bronchioles dissected from preselected regions of the right middle lobe were studied by transmission electron microscopy. Dissected terminal airways were sectioned in a longitudinal plane through their midlumen. From these dissected airways, 4 subregions of the centriacinus were then examined: (1) terminal bronchiole, (2) respiratory bronchiole, (3) centriacinar alveolar duct wall, and (4) centriacinar alveolar septa. The results of this study showed that after chronic ozone exposure, there was a 13 to 21% decrease in terminal bronchiole luminal diameter but no significant change in total terminal bronchiole volume. Analysis of measured volume and diameter changes in the terminal bronchiole, coupled with volume increases in respiratory bronchiole, support the conclusion that respiratory bronchiole (RB) is formed from the centriacinar alveolar duct.

Barr, B.C.; Hyde, D.M.; Plopper, C.G.; Dungworth, D.L.

1988-04-01

395

Chronic liver injury in phenoxy herbicide-exposed Vietnam veterans.  

PubMed

Reports of hepatotoxic injury in Vietnam veterans exposed to phenoxy herbicides (mainly, 2,4-D and 2,4,5-T) initiated a retrospective cohort study of veterans self-reporting exposure to Agent Orange (AO) while serving in Vietnam from 1962 to 1971. Historical, medical, and laboratory information was obtained in a subcohort of 100 randomly selected veterans from a pool of 350 registrants. An occupational work exposure ranking system was designed to estimate individual exposure to phenoxy herbicide and its contaminant, dioxin (TCDD). Job classifications were determined by military job codes. Military application of the herbicides used in Vietnam were derived from the National Research Council Report based on the Herbs tapes. Health examination included tests of body systems affected by TCDD and similar agents, e.g., hemopoietic system, cholesterol/lipid metabolism, hepatic function, and skin lesions. Skin rash was utilized as a marker disease, since no case of true chloracne was found among the cohort. The cohort was divided into those with (R) and without (NR) a reported rash during or after the Vietnam tour. The R group had higher frequency (31%) of abnormal liver studies of all types than the NR group (18%). Of the 14 Vietnam veterans with persistent serum transaminase elevations, 86% reported a rash. Abnormal liver functions correlated with herbicide exposure index in both groups, but was more prominent in the R group. Study of the exposure index components showed that the liver abnormalities were related to the months of exposure and not to job classification or exposure rank. Viral hepatitis and alcoholism among both groups accounted for the association between liver abnormalities and cumulative exposure to AO. These data provide strong supportive evidence that chronic liver abnormalities among Vietnam veterans applying to the AO Registry are mainly due to viral or alcoholic causality and not to herbicides and their TCDD contaminant. PMID:1425508

Tamburro, C H

1992-10-01

396

Cloning assay thresholds on cells exposed to ultrafast laser pulses  

NASA Astrophysics Data System (ADS)

The influence of the peak power, laser wavelength and the pulse duration of near infrared ultrashort laser pulses on the reproduction behavior of Chinese hamster ovary (CHO) cells has been studied. In particular, we determined the cloning efficiency of single cell pairs after exposure to ultrashort laser pulses with an intensity in the range of GW/cm2 and TW/cm2. A total of more than 3500 non- labeled cells were exposed to a highly focused scanning beam of a multiphoton laser microscope with 60 microsecond(s) pixel dwell time per scan. The beam was provided by a tunable argon ion laser pumped mode-locked 76 MHz Titanium:Sapphire laser as well as by a compact solid-state laser based system (Vitesse) at a fixed wavelength of 800 nm. Pulse duration (tau) was varied in the range of 100 fs to 4 ps by out-of- cavity pulse-stretching units consisting of SF14 prisms and blazed gratings. Within an optical (laser power) window CHO cells could be scanned for hours without severe impact on reproduction behavior, morphology and vitality. Ultrastructural studies reveal that mitochondria are the major targets of intense destructive laser pulses. Above certain laser power P thresholds, CHO cells started to delay or failed to undergo cell division and, in part, to develop uncontrolled cell growth (giant cell formation). The damage followed a P2/(tau) relation which is typical for a two- photon excitation process. Therefore, cell damage was found to be more pronounced at shorter pulses. Due to the same P2/(tau) relation for the efficiency of fluorescence excitation, two-photon microscopy of living cells does not require extremely short femtosecond laser pulses nor pulse compression units. Picosecond as well as femtosecond lasers can be used as efficient light sources in safe two photon fluorescence microscopy. Only in three photon fluorescence microscopy, femtosecond laser pulses are advantageous over picosecond pulses.

Koenig, Karsten; Riemann, Iris; Fischer, Peter; Becker, Thomas P.; Oehring, Hartmut; Halbhuber, Karl-Juergen

1999-06-01

397

Cloning assay thresholds on cells exposed to ultrafast laser pulses  

NASA Astrophysics Data System (ADS)

The influence of the peak power, laser wavelength and the pulse duration of near infrared (NIR) ultrashort laser pulses on the reproduction behavior of Chinese hamster ovary (CHO) cells has been studied. In particular we determined the cloning efficiency of single cell pairs after exposure to ultrashort laser pulses with an intensity in the range of GW/cm2 and TW/cm2. A total of more than 3500 non- labeled cells were exposed to a highly focused scanning beam of a multiphoton laser microscope with 60 microsecond pixel dwell time per scan. The beam was provided by a tunable argon ion laser pumped mode-locked 76 MHz Titanium:Sapphire laser as well as by a compact solid-state laser based system (Vitesse) at a fixed wavelength of 800 nm. Pulse duration (tau) was varied in the range of 100 fs to 4 ps by out-of-cavity pulse- stretching units consisting of SF14 prisms and blazed gratings. Within an optical (laser power) window CHO cells could be scanned for hours without severe impact on reproduction behavior, morphology and vitality. Ultrastructural studies reveal that mitochondria are the major targets of intense destructive laser pulses. Above certain laser power P thresholds, CHO cells started to delay or failed to undergo cell division and, in part, to develop uncontrolled cell growth (giant cell formation). The damage followed a P2/(tau) relation which is typical for a two-photon excitation process. Therefore, cell damage was found to be more pronounced at shorter pulses. Due to the same P2/(tau) relation for the efficiency of fluorescence excitation, two- photon microscopy of living cells does not require extremely short femtosecond laser pulses nor pulse compression units. Picosecond as well as femtosecond layers can be used as efficient light sources in safe two photon fluorescence microscopy. Only in three photon fluorescence microscopy, femtosecond laser pulses are advantageous over picosecond pulses.

Koenig, Karsten; Riemann, Iris; Fischer, Peter; Becker, Thomas P.; Oehring, Hartmut; Halbhuber, Karl-Juergen

1999-06-01

398

Ethnic minority health in Vietnam: a review exposing horizontal inequity  

PubMed Central

Background Equity in health is a pressing concern and reaching disadvantaged populations is necessary to close the inequity gap. To date, the discourse has predominately focussed on reaching the poor. At the same time and in addition to wealth, other structural determinants that influence health outcomes exist, one of which is ethnicity. Inequities based on group belongings are recognised as ‘horizontal’, as opposed to the more commonly used notion of ‘vertical’ inequity based on individual characteristics. Objective The aim of the present review is to highlight ethnicity as a source of horizontal inequity in health and to expose mechanisms that cause and maintain this inequity in Vietnam. Design Through a systematic search of available academic and grey literature, 49 publications were selected for review. Information was extracted on: a) quantitative measures of health inequities based on ethnicity and b) qualitative descriptions explaining potential reasons for ethnicity-based health inequities. Results Five main areas were identified: health-care-seeking and utilization, maternal and child health, nutrition, infectious diseases, and oral health and hygiene. Evidence suggests the presence of severe health inequity in health along ethnic lines in all these areas. Research evidence also offers explanations derived from both external and internal group dynamics to this inequity. It is reported that government policies and programs appear to be lacking in culturally adaptation and sensitivity, and examples of bad attitudes and discrimination from health staff toward minority persons were identified. In addition, traditions and patriarchal structures within ethnic minority groups were seen to contribute to the maintenance of harmful health behaviors within these groups. Conclusion Better understandings of the scope and pathways of horizontal inequities are required to address ethnic inequities in health. Awareness of ethnicity as a determinant of health, not only as a covariate of poverty or living area, needs to be improved, and research needs to be designed with this in mind. PMID:23462107

Malqvist, Mats; Hoa, Dinh Thi Phuong; Liem, Nguyen Thanh; Thorson, Anna; Thomsen, Sarah

2013-01-01

399

Polyamines and polyamine biosynthesis in cells exposed to hyperthermia  

SciTech Connect

The issue of how polyamines act to sensitize cultured cells to the lethal effects of hyperthermia was investigated using Chinese hamster cells which were induced to express thermotolerance. Intracellular levels of these naturally occurring polycations were manipulated in certain situations by treating whole cells with methylglyoxal bis-(guanylhydrazone), an inhibitor of the S-adenosyl-L-methionine decarboxylases. Exogenous spermine as low as 100 ..mu..M in the culture media dramatically sensitized cells expressing thermotolerance to the lethal effects of subsequent 42/sup 0/C exposures. When thermotolerance was differentially induced in cultures exposed to 42.4/sup 0/C by varying the rate of heating from 37 to 42.4/sup 0/C, the most resistant cells and the highest levels of intracellular spermidine and spermine. This finding was explainable in part by the observation that the putrescine-dependent S-adenosyl-L-methionine decarboxylase activity was minimally affected in cells expressng the greatest degree of thermotolerance. When this enzyme activity was inhibited by drug, lowered intracellular polyamine levels did not correspond with subsequent survival responses to heat. Interestingly, cultures treated with methylglyoxal bis-(guanylhydrazone) 24 hr previous to heat exposure showed a reduced capacity to express rate of heating-induced thermotolerance. Together, these results demonstrate that the polyamines, especially spermidine and spermine, enhance hyperthermia-induced cell killing by some mechanism involving the plasma membrane. Further, our data suggest that methylglyoxal bis-(guanylhydrazone) can act to affect thermal responses by a mechanism(s) other than modification of intracellular polyamine levels.

Gerner, E.W.; Stickney, D.G.; Herman, T.S.; Fuller, D.J.

1983-02-01

400

Fluctuations of an Exposed ?-Helix Involved in Lipoxygenase Substrate Recognition  

PubMed Central

The second helix in lipoxygenases adapts to permit substrate access to the active site, but details of this process are varied and poorly understood. We therefore examined the dynamics of helix 2 in solutions of spin-labeled soybean lipoxygenase-1 and spin relaxation at 60 K of the spin-labels by catalytic iron. Helix 2 in soybean lipoxygenase structures is surface-exposed and contains one turn of ?-helix, centrally located. A site-directed spin-label scan of 18 of the 21 helix 2 residues, and electron paramagnetic resonance, showed that the ?-helical segment became unusually mobile, on a nanosecond time scale, under conditions favoring substrate binding (pH 9 and lipid addition), while segments before and after had relatively unchanged dynamics. Backbone dynamics of residues in the ?-helical segment appeared to be correlated, at pH 9. Samples also were frozen to examine the polarity and proticity of the local environments, the effect of the local environment on intrinsic relaxation, and dipolar relaxation by two symmetries of catalytic iron. The average hyperfine tensor component, Azz, of four ?-helix residues decreased by 1.75 G, with an increase in pH from 7 to 9, while it remained unaffected for nearby buried residues. Power saturation data suggested the change in polarity specific to the ?-helix altered the intrinsic relaxation rates. Different symmetries of iron contributed to distance-dependent magnetic relaxation. We interpret these data to mean that a ?-helix in the second helix of plant lipoxygenases is highly dynamic and is the site where lipid chains penetrate to inner helices that outline the substrate pocket. PMID:25036469

2014-01-01

401

Respiratory epithelial cell lines exposed to anoxia produced inflammatory mediator  

PubMed Central

Human epithelial cell lines were utilized to examine the effects of anoxia on cellular growth and metabolism. Three normal human epithelial cells lines (A549, NHBE, and BEAS-2B) as well as a cystic fibrosis cell line (IB3-1) and its mutation corrected cell line (C38) were grown in the presence and absence of oxygen for varying periods of time. Interleukin-8 (IL-8) levels were measured by enzyme-linked immunosorbent assay technique. Cellular metabolism and proliferation were assayed by determining mitochondrial oxidative burst activity by tetrazolium compound reduction. The viability of cells was indirectly measured by lactate dehydrogenase release. A549, NHBE, and BEAS-2B cells cultured in the absence of oxygen showed a progressive decrease in metabolic activity and cell proliferation after one to three days. There was a concomitant increase in IL-8 production. Cell lines from cystic fibrosis (CF) patients did not show a similar detrimental effect of anoxia. However, the IL-8 level was significantly increased only in IB3-1 cells exposed to anoxia after two days. Anoxia appears to affect certain airway epithelial cell lines uniquely with decreased cellular proliferation and a concomitant increased production of a cytokine with neutrophilic chemotactic activity. The increased ability of the CF cell line to respond to anoxia with increased secretion of inflammatory cytokines may contribute to the inflammatory damage seen in CF bronchial airway. This study indicates the need to use different cell lines in in vitro studies investigating the role of epithelial cells in airway inflammation and the effects of environmental influences. PMID:23301190

Shahriary, Cyrus M.; Nussbaum, Eliezer

2012-01-01

402

Transcriptomic profiling in Silurana tropicalis testes exposed to finasteride.  

PubMed

Investigations of endocrine disrupting chemicals found in aquatic ecosystems with estrogenic and androgenic modes of action have increased over the past two decades due to a surge of evidence of adverse effects in wildlife. Chemicals that disrupt androgen signalling and steroidogenesis can result in an imbalanced conversion of testosterone (T) into 17?-estradiol (E2) and other androgens such as 5?-dihydrotestosterone (5?-DHT). Therefore, a better understanding of how chemicals perturb these pathways is warranted. In this study, the brain, liver, and testes of Silurana tropicalis were exposed ex vivo to the human drug finasteride, a potent steroid 5?-reductase inhibitor and a model compound to study the inhibition of the conversion of T into 5?-DHT. These experiments were conducted (1) to determine organ specific changes in sex steroid production after treatment, and (2) to elucidate the transcriptomic response to finasteride in testicular tissue. Enzyme-linked immunosorbent assays were used to measure hormone levels in media following finasteride incubation for 6 h. Finasteride significantly increased T levels in the media of liver and testis tissue, but did not induce any changes in E2 and 5?-DHT production. Gene expression analysis was performed in frog testes and data revealed that finasteride treatment significantly altered 1,434 gene probes. Gene networks associated with male reproduction such as meiosis, hormone biosynthesis, sperm entry, gonadotropin releasing hormone were affected by finasteride exposure as well as other pathways such as oxysterol synthesis, apoptosis, and epigenetic regulation. For example, this study suggests that the mode of action by which finasteride induces cellular damage in testicular tissue as reported by others, is via oxidative stress in testes. This data also suggests that 5-reductase inhibition disrupts the expression of genes related to reproduction. It is proposed that androgen-disrupting chemicals may mediate their action via 5-reductases and that the effects of environmental pollutants are not limited to the androgen receptor signalling. PMID:24530632

Bissegger, Sonja; Martyniuk, Christopher J; Langlois, Valérie S

2014-07-01

403

Dating and quantification of erosion processes based on exposed roots  

NASA Astrophysics Data System (ADS)

Soil erosion is a key driver of land degradation and heavily affects sustainable land management in various environments worldwide. An appropriate quantification of rates of soil erosion and a localization of hotspots are therefore critical, as sediment loss has been demonstrated to have drastic consequences on soil productivity and fertility. A consistent body of evidence also exists for a causal linkage between global changes and the temporal frequency and magnitude of erosion, and thus calls for an improved understanding of dynamics and rates of soil erosion for an appropriate management of landscapes and for the planning of preventive or countermeasures. Conventional measurement techniques to infer erosion rates are limited in their temporal resolution or extent. Long-term erosion rates in larger basins have been analyzed with cosmogenic nuclides, but with lower spatial and limited temporal resolutions, thus limiting the possibility to infer micro-geomorphic and climatic controls on the timing, amount and localization of erosion. If based on exposed tree roots, rates of erosion can be inferred with up to seasonal resolution, over decades to centuries of the past and for larger surfaces with homogenous hydrological response units. Root-based erosion rates, thus, constitute a valuable alternative to empirical or physically-based approaches, especially in ungauged basins, but will be controlled by individual or a few extreme events, so that average annual rates of erosion might be highly skewed. In this contribution, we review the contribution made by this biomarker to the understanding of erosion processes and related landform evolution. We report on recent progress in root-based erosion research, illustrate possibilities, caveats and limitations of reconstructed rates, and conclude with a call for further research on various aspects of root-erosion research and for work in new geographic regions.

Stoffel, Markus; Corona, Christophe; Ballesteros-Cánovas, Juan Antonio; Bodoque, José Maria

2013-08-01

404

EXPOSE, an astrobiological exposure facility on the international space station - from proposal to flight.  

PubMed

Following an European Space Agency announcement of opportunity in 1996 for "Externally mounted payloads for 1st utilization phase" on the International Space Station (ISS), scientists working in the fields of astrobiology proposed experiments aiming at longterm exposure of a variety of chemical compounds and extremely resistant microorganisms to the hostile space environment. The ESA exposure facility EXPOSE was built and an operations' concept was prepared. The EXPOSE experiments were developed through an intensive pre-flight experiment verification test program. 12 years later, two sets of astrobiological experiments in two EXPOSE facilities have been successfully launched to the ISS for external exposure for up to 1.5 years. EXPOSE-E, now installed at the balcony of the European Columbus module, was launched in February 2008, while EXPOSE-R took off to the ISS in November 2008 and was installed on the external URM-D platform of the Russian Zvezda module in March 2009. PMID:19629743

Rabbow, Elke; Horneck, Gerda; Rettberg, Petra; Schott, Jobst-Ulrich; Panitz, Corinna; L'Afflitto, Andrea; von Heise-Rotenburg, Ralf; Willnecker, Reiner; Baglioni, Pietro; Hatton, Jason; Dettmann, Jan; Demets, René; Reitz, Günther

2009-12-01

405

Analysis of 13 32P-DNA Postlabeling Studies on Occupational Cohorts Exposed to Air Pollution  

Microsoft Academic Search

Industrial and urban workers may be exposed to significant levels of air pollutants resulting from the incomplete combustion of organic matter. The authors performed a meta-analysis of 13 DNA-adduct studies ( 32 P-DNA postlabeling technique) on occupational cohorts exposed to air pollution. The association between levels of DNA adducts and air pollution exposure was significant both in heavily exposed industrial

M. Peluso; M. Ceppi; A. Munnia; R. Puntoni; S. Parodi

2001-01-01

406

Behavioral Outcome of Preschoolers Exposed Prenatally to Cocaine: Role of Maternal Behavioral Health  

Microsoft Academic Search

Objective: To examine the impact of prenatal cocaine exposure and maternal behavioral health (recent drug use and psychological functioning) on child behavior at age 5 years. Method: In this longitudinal investigation, maternal report of child behavior was assessed using the Achen- bach Child Behavior Checklist (CBCL) in 140 cocaine-exposed and 181 noncocaine-exposed (61 alcohol, to- bacco, and\\/or marijuana-exposed, and 120

Veronica H. Accornero; Connie E. Morrow; Emmalee S. Bandstra; Arnise L. Johnson; James C. Anthony

2002-01-01

407

Polymorphic trial in oxidative damage of arsenic exposed Vietnamese  

SciTech Connect

Arsenic causes DNA damage and changes the cellular capacity for DNA repair. Genes in the base excision repair (BER) pathway influence the generation and repair of oxidative lesions. Single nucleotide polymorphisms (SNPs) in human 8-oxoguanine DNA glycosylase (hOGG1) Ser326Cys; apurinic/apyrimidinic endonuclease (APE1) Asp148Glu; X-ray and repair and cross-complementing group 1 (XRCC1) Arg280His and Arg399Gln in the BER genes were analyzed, and the relationship between these 4 SNPs and the urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations of 100 Vietnamese population exposed to arsenic was investigated. Individuals with hOGG1 326Cys/Cys showed significantly higher urinary 8-OHdG concentrations than did those with 326 Ser/Cys and Ser/Ser. As for APE1 Asp148Glu, heterozygous subjects showed significantly higher urinary 8-OHdG concentrations than did those homozygous for Asp/Asp. Moreover, global ethnic comparison of the allelic frequencies of the 4SNPs was performed in 10 population and previous reported data. The mutant allele frequencies of hOGG1 Ser326Cys in the Asian populations were higher than those in the African and Caucasian populations. As for APE1 Asp148Glu, Caucasians showed higher mutant frequencies than those shown by African and Asian populations. Among Asian populations, the Bangladeshi population showed relatively higher mutant allele frequencies of the APE1 Asp148Glu polymorphism. This study is the first to demonstrate the existence of genetic heterogeneity in a worldwide distribution of SNPs (hOGG1 Ser326Cys, APE1 Asp148Glu, XRCC1 Arg280His, and XRCC1 Arg399Gln) in the BER genes. - Highlights: > We showed that hOGG1 and APE1 are associated with urinary 8-OHdG concentrations. > We showed the existence of inter-ethnic differences in hOGG1 and APE1 polymorphism. > These polymorphisms is a genetic marker of susceptibility to oxidative stress.

Fujihara, Junko [Department of Legal Medicine, Faculty of Medicine, Shimane University, Izumo, Shimane (Japan); Soejima, Mikiko [Department of Forensic Medicine and Human Genetics, Kurume University School of Medicine, Kurume, Fukuoka (Japan); Yasuda, Toshihiro [Division of Medical Genetics and Biochemistry, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Fukui (Japan); Koda, Yoshiro [Department of Forensic Medicine and Human Genetics, Kurume University School of Medicine, Kurume, Fukuoka (Japan); Kunito, Takashi [Department of Environmental Sciences, Faculty of Science, Shinshu University, Matsumoto, Nagano (Japan); Iwata, Hisato; Tanabe, Shinsuke [Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama Ehime (Japan); Takeshita, Haruo, E-mail: htakeshi@med.shimane-u.ac.jp [Department of Legal Medicine, Faculty of Medicine, Shimane University, Izumo, Shimane (Japan)

2011-10-15

408

What's exposed? Mapping elements at risk from space  

NASA Astrophysics Data System (ADS)

The world has suffered from severe natural disasters over the last decennium. The earthquake in Haiti in 2010 or the typhoon "Haiyan" hitting the Philippines in 2013 are among the most prominent examples in recent years. Especially in developing countries, knowledge on amount, location or type of the exposed elements or people is often not given. (Geo)-data are mostly inaccurate, generalized, not up-to-date or even not available at all. Thus, fast and effective disaster management is often delayed until necessary geo-data allow an assessment of effected people, buildings, infrastructure and their respective locations. In the last decade, Earth observation data and methods have developed a product portfolio from low resolution land cover datasets to high resolution spatially accurate building inventories to classify elements at risk or even assess indirectly population densities. This presentation will give an overview on the current available products and EO-based capabilities from global to local scale. On global to regional scale, remote sensing derived geo-products help to approximate the inventory of elements at risk in their spatial extent and abundance by mapping and modelling approaches of land cover or related spatial attributes such as night-time illumination or fractions of impervious surfaces. The capabilities and limitations for mapping physical exposure will be discussed in detail using the example of DLR's 'Global Urban Footprint' initiative. On local scale, the potential of remote sensing particularly lies in the generation of spatially and thematically accurate building inventories for the detailed analysis of the building stock's physical exposure. Even vulnerability-related indicators can be derived. Indicators such as building footprint, height, shape characteristics, roof materials, location, and construction age and structure type have already been combined with civil engineering approaches to assess building stability for large areas. Especially last generation optical sensors - often in combination with digital surface models - featuring very high geometric resolutions are perceived as advantageous for operational applications, especially for small to medium scale urban areas. With regard to user-oriented product generation in the FP-7project SENSUM, a multi-scale and multi-source reference database has been set up to systematically screen available products - global to local ones - with regard to data availability in data-rich and data-poor countries. Thus, the higher ranking goal in this presentation is to provide a systematic overview on EO-based data sets and their individual capabilities and limitations with respect to spatial, temporal and thematic details to support decision-making in before, during and after natural disasters.

Taubenböck, Hannes; Klotz, Martin; Geiß, Christian

2014-05-01

409

Biomarker responses in river otters experimentally exposed to oil contamination.  

PubMed

Investigations in Prince William Sound (Alaska, USA) following the Exxon Valdez oil spill (EVOS) revealed that river otters (Lontra canadensis) on oiled shores had lower body mass and elevated values of biomarkers, than did otters living on nonoiled shores. In addition, otters from oiled areas selected different habitats, had larger home ranges, and less diverse diets than animals living in nonoiled areas. These differences between river otters from oiled shores and those from nonoiled areas strongly suggested that oil contamination had an effect on physiological and behavioral responses of otters. In this study, we explored the effects of crude oil contamination on river otters experimentally. We hypothesized that exposure to oil would result in elevated values of biomarkers, indicating induced physiological stress. Fifteen wild-caught male river otters were exposed to two levels of weathered crude oil (i.e., control, 5 ppm/day/kg body mass, and 50 ppm/day/kg body mass) under controlled conditions in captivity at the Alaska Sealife Center in Seward (Alaska, USA). Responses of captive river otters to oil ingestion provided mixed results in relation to our hypotheses. Although hemoglobin (Hb, and associated red blood cells) and white blood cells, and possibly interleukin-6 immunoreactive responded in the expected manner, other parameters did not. Aspartate aminotransferase, alanine aminotransferase, and haptoglobin (Hp), did not increase in response to oiling or decreased during rehabilitation. Conversely, principle-component analysis identified values of alkaline phosphatase as responding to oil ingestion in river otters. Our results suggested that opposing processes were concurring in the oiled otters. Elevated production of Hp in response to tissue damage by hydrocarbons likely occurred at the same time with increased removal of Hp-Hb complex from the serum, producing an undetermined pattern in the secretion of Hp. Thus, the use of individual biomarkers as indicators of exposure to pollutants may lead to erroneous conclusions because interactions in vivo can be complicated and act in opposite directions. Additionally, the biomarkers used in investigating effects of oiling on live animals usually are related to the heme molecule. Because of the opposing processes that may occur within an animal, data from a suite of heme-related biomarkers may produce results that are difficult to interpret. Therefore, we advocate the exploration and development of other biomarkers that will be independent from the heme cycle and provide additional information to the effect of oiling on live mammals. PMID:11504223

Ben-David, M; Duffy, L K; Bowyer, R T

2001-07-01

410

Recently Exposed Fumarole Fields Near Mullet Island, Imperial County, California  

NASA Astrophysics Data System (ADS)

New field observations, lidar measurements, aerial imaging and preliminary laboratory measurements of mud samples are reported of three formerly submerged fumarole fields in the Salton Trough near Mullet Island in southeastern California, USA. The fumarole fields have recently been exposed as the Salton Sea level has dropped. The largest of the three fields visited in January 2011 is irregular in outline with a marked northeast elongation. It is roughly 400 meters long and 120 meters wide. The field consists of approximately one hundred warm to boiling hot (100° C) mud volcanoes (0.1 - 2 m in height), several hundred mud pots, and countless CO2 gas vents. Unusual shaped mud volcanoes in the form of vertical tubes with central vents were observed in many places. Lidar measurements were obtained in the time period Nov 9-13, 2010 using an Optech Orion 200M lidar from an elevation 800 m AGL. They reveal that the terrain immediately surrounding the two fields that are above water level reside on a low (~0.5 m high) gently sloping mound about 500 m across that shows no evidence of lineaments indicative of surface faulting. With other geothermal features, the fumaroles define a well-defined line marking the probable trace of the Calipatria fault. Although the precise locations is uncertain, it appears to define a straight line 4 km long between the Davis-Schrimpf mud volcanoes and Mullet Island. Mullet Island is one of five late Quaternary rhyolitic volcanic necks in the immediate area of the fumaroles. The Calipatria fault is subparallel to the San Andreas and Imperial faults and only one of many verified or suspected faults (including cross faults) in the complex tectonic setting of the Salton Trough. Mud from several volcanoes was analyzed using scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). One sample contained boussingaultite, (NH4)2Mg(SO4)2.6(H2O), a rare mineral that is known to sublime under fumarolic conditions, possibly by ammoniation of hydrated MgSO4. As the Salton Sea level continues to drop, the third fumarole field is expected to surface in the next couple of years. It is also likely that as more land emerges, many of the CO2 gas seeps currently under water will begin to for mud volcanoes and mud pots, most of them along the same NW trending axis as the others. At about the same time a land bridge will form to Mullet Island, the first in about 60 years.

Lynch, D. K.; Hudnut, K.; Adams, P.; Bernstein, L.

2011-12-01

411

Toxicological outcomes in rats exposed to inhaled ethanol during gestation.  

PubMed

Recent legislation has encouraged replacing petroleum-based fuels with renewable alternatives including ethanol, which is typically blended with gasoline in the United States at concentrations up to 10%, with allowances for concentrations up to 85% for some vehicles. Efforts to increase the amount of ethanol in gasoline have prompted concerns about the potential toxicity of inhaled ethanol vapors from these fuels. The well-known sensitivity of the developing nervous and immune systems to ingested ethanol, and the lack of information about its toxicity by inhalation prompted the present work on its potential developmental effects in a rat model. Pregnant Long-Evans rats were exposed for 6.5h/day on days 9-20 of gestation to clean air or ethanol vapor at concentrations of 5000, 10,000, or 21,000ppm, which resulted in estimated peak blood ethanol concentrations (BECs) of 2.3, 6.7, and 192mg/dL, respectively. No overt toxicity in the dams was observed. Ethanol did not affect litter size or weight, or postnatal weight gain in the pups. Motor activity was normal in offspring through postnatal day (PND) 29. On PND 62, the 5000 and 21,000ppm groups were more active than controls. On PND 29 and 62, offspring were tested with a functional observational battery, which revealed small changes in the neuromuscular and sensorimotor domains that were not systematically related to dose. Cell-mediated and humoral immunity were not affected by ethanol exposure in 6-week-old offspring. Systolic blood pressure was increased by 10,000ppm ethanol in males at PND 90 but not at PND 180. No differences in lipoprotein profile, liver function, or kidney function were observed. In summary, prenatal exposure to inhaled ethanol caused some mild changes in physiological and behavioral development in offspring that were not clearly related to inhaled concentration or BEC, and did not produce detectable changes in immune function. This low toxicity of inhaled ethanol may result from the slow rise in BEC by the inhalation route. PMID:25092052

Beasley, Tracey E; Evansky, Paul A; Martin, Sheppard A; McDaniel, Katherine L; Moser, Virginia C; Luebke, Robert W; Norwood, Joel; Rogers, John M; B Copeland, Carey; Bushnell, Philip J

2014-01-01

412

Mortality patterns among workers exposed to acrylamide: 1994 follow up  

PubMed Central

OBJECTIVE: To update the mortality experience of a cohort of 8508 workers with potential exposure to acrylamide at three plants in the United States from 1984-94. METHODS: Analyses of standardised mortality ratios (SMR) with national and local rates and relative risk (RR) regression modelling were performed to assess site specific cancer risks by demographic and work history factors, and exposure indicators for acrylamide and muriatic acid. RESULTS: For the 1925-94 study period, excess and deficit overall mortality risks were found for cancer sites of interest: brain and other central nervous system (CNS) (SMR 0.65, 95% confidence interval (95% CI) 0.36 to 1.09), thyroid gland (SMR 2.11, 95% CI 0.44 to 6.17), testis and other male genital organs (SMR 0.28, 95% CI 0.01 to 1.59), and cancer of the respiratory system (SMR 1.10, 95% CI 0.99 to 1.22); however, none was significant or associated with exposure to acrylamide. A previously reported excess mortality risk of cancer of the respiratory system at one plant remained increased among workers with potential exposure to muriatic acid (RR 1.50, 95% CI 0.86 to 2.59), but was only slightly increased among workers exposed or unexposed to acrylamide. In an exploratory exposure-response analysis of rectal, oesophageal, pancreatic, and kidney cancer, we found increased SMRs for some categories of exposure to acrylamide, but little evidence of an exposure-response relation. A significant 2.26-fold risk (95% CI 1.03 to 4.29) was found for pancreatic cancer among workers with cumulative exposure to acrylamide > 0.30 mg/m3.years; however, no consistent exposure-response relations were detected with the exposure measures considered when RR regression models were adjusted for time since first exposure to acrylamide. CONCLUSION: The contribution of 1115 additional deaths and nearly 60,000 person-years over the 11 year follow up period corroborate the original cohort study findings of little evidence for a causal relation between exposure to acrylamide and mortality from any cancer sites, including those of initial interest. This is the most definitive study of the human carcinogenic potential of exposure to acrylamide conducted to date.   PMID:10448327

Marsh, G. M.; Lucas, L. J.; Youk, A. O.; Schall, L. C.

1999-01-01

413

Avermectins: novel insecticides, acaricides and nematicides from a soil microorganism  

Microsoft Academic Search

Summary The avermectins, streptomycete-derived macrocyclic lactones originally isolated as antiparasitic agents, have also demonstrated high potencies in laboratory evaluations against insect pests in several orders, phytophagous mites and the plant-parasitic nematode,Meloidogyne. Studies suggest that the avermectins' mechanism of toxicity is fundamentally different from those associated with current natural and synthetic pesticides.

I. Putter; J. G. Mac Connell; F. A. Preiser; A. A. Haidri; S. S. Ristich; R. A. Dybas

1981-01-01

414

Posttraumatic Stress in Children and Adolescents Exposed to Family Violence: II. Treatment  

Microsoft Academic Search

Interventions for youth exposed to family violence recently have incorporated a trauma focus with the objective of reducing posttraumatic stress disorder symptoms along with alleviating other wide-ranging childhood disorders. This article describes generally agreed-upon treatment components for youth exposed to violence in the home (specifically, children who are physically abused or witnesses to interparental violence), including reexposure interventions, education about

Katrina A. Vickerman; Gayla Margolin

2007-01-01

415

Elevated Trace Element Concentrations in Southern Toads, Bufo terrestris, Exposed to Coal Combustion Waste  

E-print Network

Elevated Trace Element Concentrations in Southern Toads, Bufo terrestris, Exposed to Coal, and behavioral abnormalities in amphibians to coal combustion wastes (coal ash). Few studies, however, have determined trace element concentrations in amphibians exposed to coal ash. In the current study we compare

Hopkins, William A.

416

Detrimental Effects Associated with Trace Element Uptake in Lake Chubsuckers (Erimyzon sucetta) Exposed to Polluted Sediments  

E-print Network

February 2000 Abstract. Lake chubsuckers (Erimyzon sucetta) were exposed to coal ash­polluted sedimentsDetrimental Effects Associated with Trace Element Uptake in Lake Chubsuckers (Erimyzon sucetta) Exposed to Polluted Sediments W. A. Hopkins,1,2 J. W. Snodgrass,1,3 J. H. Roe,1 B. P. Jackson,1 J. C

Hopkins, William A.

417

9 CFR 73.8 - Cattle infected or exposed during transit.  

Code of Federal Regulations, 2010 CFR

...false Cattle infected or exposed during transit. 73.8 Section 73.8 Animals...8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined...en route. Should healthy cattle in transit from a State not quarantined by...

2010-01-01

418

Fish Embryos Exposed to Oil From BP Spill Develop Deformities, a Study Finds  

E-print Network

Fish Embryos Exposed to Oil From BP Spill Develop Deformities, a Study Finds By MICHAEL WINESMARCH no evidence that the oil spill had reduced fish populations. "The oil concentrations used in these lab 24, 2014 Embryos of tuna and amberjack that were exposed to crude oil collected from the Deepwater

Grosell, Martin

419

Chronic toxicity of the bromoxynil formulation Buctril ® to Daphnia magna exposed continuously and intermittently  

Microsoft Academic Search

Two chronic toxicity tests were conducted in which Daphnia magna were either continuously or intermittently exposed to bromoxynil octanoate (BO; as Buctril®) for 28 d. In the intermittent exposure test, daphnids were exposed to daily pulses of BO with 24-h mean concentrations equal to those in the continuous exposure test, and the peak concentrations were three times the 24-h mean

Kevin J. Buhl; Steven J. Hamilton; James C. Schmulbach

1993-01-01

420

SYSTEMS FOR EXPOSING MICE TO 2,450-MHZ ELECTROMAGNETIC FIELDS  

EPA Science Inventory

Two systems for exposing mice to 2,450-MHz electromagnetic fields are described. In a waveguide system, four mice were placed in a Styrofoam cage and exposed dorsally to circularly polarized electromagnetic fields. The temperature and humidity in the mouse holder were kept consta...