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1

Increased transcription of Glutathione S-transferases in acaricide exposed scabies mites  

PubMed Central

Background Recent evidence suggests that Sarcoptes scabiei var. hominis mites collected from scabies endemic communities in northern Australia show increasing tolerance to 5% permethrin and oral ivermectin. Previous findings have implicated detoxification pathways in developing resistance to these acaricides. We investigated the contribution of Glutathione S-transferase (GST) enzymes to permethrin and ivermectin tolerance in scabies mites using biochemical and molecular approaches. Results Increased in vitro survival following permethrin exposure was observed in S. scabiei var. hominis compared to acaricide naïve mites (p < 0.0001). The addition of the GST inhibitor diethyl maleate restored in vitro permethrin susceptibility, confirming GST involvement in permethrin detoxification. Assay of GST enzymatic activity in mites demonstrated that S. scabiei var. hominis mites showed a two-fold increase in activity compared to naïve mites (p < 0.0001). Increased transcription of three different GST molecules was observed in permethrin resistant S. scabiei var. canis- mu 1 (p < 0.0001), delta 1 (p < 0.001), and delta 3 (p < 0.0001). mRNA levels of GST mu 1, delta 3 and P-glycoprotein also significantly increased in S. scabiei var. hominis mites collected from a recurrent crusted scabies patient over the course of ivermectin treatment. Conclusions These findings provide further support for the hypothesis that increased drug metabolism and efflux mediate permethrin and ivermectin resistance in scabies mites and highlight the threat of emerging acaricide resistance to the treatment of scabies worldwide. This is one of the first attempts to define specific genes involved in GST mediated acaricide resistance at the transcriptional level, and the first application of such studies to S. scabiei, a historically challenging ectoparasite. PMID:20482766

2010-01-01

2

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

3

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, ...

4

Scabies  

MedlinePLUS

... injured skin will also be infected by bacteria. Impetigo , a bacterial skin infection, may occur in skin ... you develop a bacterial skin infection (such as impetigo) in addition to the scabies infection, your doctor ...

5

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, ...

6

Scabies  

MedlinePLUS

... Epidemiology & Risk Factors Who gets it and how... Biology Stages of parasite development... Disease Signs and symptoms ... Information Scabies FAQs Workplace FAQs Epidemiology & Risk Factors Biology Disease Diagnosis Treatment Prevention & Control Resources for Health ...

7

Scabies  

MedlinePLUS

... survive more than 2-3 days away from human skin. This will kill the insects and eggs. If you find out you have scabies, you need to tell your sex partner(s) or anyone you have had close contact ...

8

Scabies.  

PubMed

Scabies infestation in humans is a complex interplay between mite, host, and host environment. New techniques for diagnosis, treatment, and eradication are constantly in flux due to varying presentations of scabetic eruptions, a dearth of especially sensitive and specific measures for diagnosis, resistances to pharmacologic therapy, and disparate regional resources. This review will provide an update on the clinical variations, detection methods, and management options. PMID:25577847

Rosamilia, Lorraine L

2014-09-01

9

Today's scabies.  

PubMed

In the past several years there has been a noticeable increase of scabies in the United States; the magnitude of this is not known. An expanding epidemic continues in most parts of the world. Scabies is frequently seen in many guises that may be difficult to diagnose: scabies in the clean, scabies incognito, nodular scabies, animal-transmitted scabies, scabies in infants, scabies with syphillis, and Norwegian scabies. If the diagnosis cannot be confirmed by identifying the mite, synthesis of suggestive features may establish the diagnosis. Recently adopted children from foreign countries, especially southeastern Asia, have had a high frequency of scabies, which may appear after the children arrive in the United States. Acute glomerulonephritis may develop in patients whose scabetic lesions are complicated by a Virulent nephritogenic streptococcal strain. PMID:1173898

Orkin, M

1975-08-25

10

Scabies Diagnosis  

MedlinePLUS

... message, please visit this page: About CDC.gov . Parasites - Scabies Parasites Home Share Compartir Diagnosis Diagnosis of a scabies ... Cases Publications Information For: Institutions Travelers Related Links Parasites A-Z Index Parasites Glossary Neglected Tropical Diseases ...

11

Scabies: Treatment  

MedlinePLUS

... message, please visit this page: About CDC.gov . Parasites - Scabies Parasites Home Share Compartir Treatment On This Page Suggested ... Cases Publications Information For: Institutions Travelers Related Links Parasites A-Z Index Parasites Glossary Neglected Tropical Diseases ...

12

Scabies: Disease Symptoms  

MedlinePLUS

... message, please visit this page: About CDC.gov . Parasites - Scabies Parasites Home Share Compartir Disease When a person is ... reaction) to the proteins and feces of the parasite. Severe itching (pruritus), especially at night, is the ...

13

Scabies: Prevention and Control  

MedlinePLUS

... message, please visit this page: About CDC.gov . Parasites - Scabies Parasites Home Share Compartir Prevention & Control When a person ... Cases Publications Information For: Institutions Travelers Related Links Parasites A-Z Index Parasites Glossary Neglected Tropical Diseases ...

14

Current treatments for scabies.  

PubMed

Scabies is a frequent interhuman ectoparasitic infection. Several treatments are available worldwide. There are local treatments: synthetic pyrethrins, benzyl benzoate, lindane, crotamiton. Recently a few studies were published concerning ivermectin, systemic antiparasitic agent use in onchocercosis treatment. We reviewed the literature with an evidence-based medicine method. We attempt to answer two questions in particular: what is the treatment of choice for common scabies in a patient otherwise in good health? What is the role of systemic ivermectin? We also report specific situations. Among local treatments, studies are heterogeneous according to products, countries, group of treated patients, with or without contact subjects, and the method of treatment application. There are very few high proof-level controlled studies. In France, a combination of benzyl benzoate 10% and sulfiram 2% is used most, according to professional consensus. The most studied product is the cream permethrin 5%, available in the USA and UK. Its efficacy seems slightly superior to lindane and less toxic. It is more efficient than crotamiton. There is no study comparing benzyl benzoate and permethrin. Concerning systemic ivermectin, five controlled studies showed its efficiency in common scabies. But its relative efficiency over local treatment has not been established. A few open studies showed its efficacy in institutional epidemic, profuse scabies and in HIV-positive patients. Local treatment of choice in common scabies remains to be determined among the four principal molecules. There is no study comparing permethrin or esdepallethrin to benzyl benzoate. In what cases should we prescribe crotamiton or lindane? Indication of ivermectin seems proved in common scabies and probably for HIV-positive patients. It remains to be determined if it should be prescribed in the first instance, be double or triple, be associated or not with local treatment. In case of keratotic scabies, ivermectin seems interesting with two applications within 1 week, and should be associated with local treatment (duration remains to be defined). Ivermectin is probably useful in institutional epidemic, and therapeutic attitude remains to be defined. Ivermectin seems to have little or no risk. Treatment must be adapted case-by-case, according to feasibility. It is still important to treat contacts, and modality of this treatment remains to be specified. PMID:12667233

Buffet, M; Dupin, N

2003-04-01

15

Scabies in the nursing home.  

PubMed

Scabies infection is antediluvian and ubiquitous both in developing and developed countries, yet often neglected. Scabies has a predilection to infect vulnerable subsets of population in crowding conditions, typically applicable to residents in the nursing home. The mite incites a unique immunological response from human hosts. Scabies does not manifest as a singular skin condition and may present atypically in older adults, the majority of nursing home residents, where delay has deleterious consequences. Further, pruritus or itching, the hallmark of scabies infection, is a common complaint from a variety of causes among older adults. Hence, the diagnosis is often delayed or missed. There are several pharmacological treatment options; long-term care practitioners need to understand the characteristics of each agent before selection. Even more relevant is the importance of nonpharmacological aspects of management, crucial in the success of averting spread or outbreaks in long-term care settings. PMID:25416848

Suwandhi, Pauline; Dharmarajan, T S

2015-01-01

16

Scabies: Frequently Asked Questions (FAQs)  

MedlinePLUS

... scabicide may be necessary. If I come in contact with a person who has scabies, should I ... page Get email updates Listen to audio/Podcast Contact Us: Centers for Disease Control and Prevention 1600 ...

17

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

18

Scabies: Workplace Frequently Asked Questions (FAQs)  

MedlinePLUS

... scabies and my job requires skin-to-skin contact with patients? Scabies usually is spread by prolonged ... page Get email updates Listen to audio/Podcast Contact Us: Centers for Disease Control and Prevention 1600 ...

19

Management of nosocomial scabies, an outbreak of occupational disease.  

PubMed

Background The optimal approach to managing institutional scabies outbreaks has yet to be defined. We report on outbreak managements are needed. Methods We report on a large outbreak of scabies in three acute care wards in a tertiary university teaching hospital in the Netherlands. Results The outbreak potentially effected 460 patients and 185 health care workers who had been exposed to the index patient. Conclusion Containment of an outbreak relies on a quick and strict implementation of appropriate infection control measures and should include simultaneous treatment of all infested persons and exposed contacts to prevent secondary spread and prolonged post-intervention surveillance. Am. J. Ind. Med. 58:577-582, 2015. © 2015 Wiley Periodicals, Inc. PMID:25777802

Jungbauer, Frank H W; Veenstra-Kyuchukova, Yanka K; Koeze, Jacqueline; KruijtSpanjer, Martijn R; Kardaun, Sylvia H

2015-05-01

20

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

21

Acaricidal activity of 9-oxo-10,11-dehydroageraphorone extracted from Eupatorium adenophorum in vitro.  

PubMed

The acaricidal activity of the 9-oxo-10,11-dehydroageraphorone (euptox A), a cadenine sesquiterpene from Eupatorium adenophorum (E. adenophorum) against Sarcoptes scabiei and Psoroptes cuniculi was tested in vitro. A complementary log-log (CLL) model was used to analyze the data of the toxicity tests in vitro. The results showed euptox A had strong toxicity against mites, killing all S. scabiei at 3 and 4 mg/ml (m/v) concentration, while 4 mg/ml euptox A was also found to kill all P. cuniculi within a 4 h period. Similarly, 2, 3 and 4 mg/ml concentration of euptox A had strong toxicity against S. scabiei, with median lethal time (LT50) values at 0.687, 0.526, 0.326 h, respectively. 3 mg/ml and 4 mg/ml showed strong acaricidal action against P. cuniculi; the LT50 values were 0.693 and 0.493 h, respectively. The median lethal concentration (LC50) values were 1.068 mg/ml for Scabies mite and 0.902 mg/ml for P. cuniculi in 2 h. The results indicate that euptox A has strong acaricidal activity and may exploit as novel drugs for the effective control of animal acariasis. PMID:24631419

Liao, Fei; Hu, Yanchun; Tan, Hui; Wu, Lei; Wang, Yunfei; Huang, Yue; Mo, Quan; Wei, Yahui

2014-05-01

22

Streptomyces scabies sp. nov., norn. rev.?  

Microsoft Academic Search

Revival of the name Streptomyces scabies is proposed for the predominant species causing common scab of potato. Common scab strains from the northeastern United States, Atlantic Canada, and Hungary were differentiated by a phenotypic analysis of 42 criteria from six atypical pathogen strains, three saprophytic streptomycetes isolated from scab lesions, and reference strains of Streptomyces griseus and Streptomyces tendae. The

D. H. LAMBERT; R. LORIA

1989-01-01

23

Streptomyces scabies 87-22 Possesses a Functional Tomatinase  

Microsoft Academic Search

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

Ryan F. Seipke; Rosemary Loria

2008-01-01

24

An elderly long-term care resident with crusted scabies  

PubMed Central

Crusted scabies is a highly contagious form of scabies. Altered immune response, nutritional deficiencies and modified host response are all risk factors for crusted scabies. The authors report a case involving a patient found to have a chronic maculopapular, erythematous rash with large hyperkeratotic, white and grey plaques on the soles of both feet. An ultimate diagnosis of crusted scabies was reached after a delay in diagnosis suspected to be caused by the similarity in appearance to more common skin conditions such as psoriasis. After topical permethrin was unsuccessful, intermittent dosing of oral ivermectin resulted in a rapid reduction in cutaneous plaques. PMID:25798153

Sandre, Matthew; Ralevski, Filip; Rau, Neil

2015-01-01

25

Efficacy of spinosad against acaricide-resistant and -susceptible Rhipicephalus (Boophilus) microplus and acaricide-susceptible Amblyomma americanum and Dermacentor variabilis  

Technology Transfer Automated Retrieval System (TEKTRAN)

Various acaricide-resistant strains of Rhipicephalus (Boophilus) microplus, representative of the major resistance mechanisms found in Mexico and Brazil were exposed to spinosad using the FAO-Larval Packet Test and FAO-Adult Immersion Test (AIT). Larvae of all strains tested were found to be suscep...

26

Scabies: more than just an irritation  

PubMed Central

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; Kemp, D; Walton, S; Currie, B

2004-01-01

27

Past, Present, and Future of Chemical Acaricides  

Technology Transfer Automated Retrieval System (TEKTRAN)

There have been many different acaricides and acaricide formulations used throughout the history of tick control. Originally, various mixtures of crude oil, lard, sulfur, and kerosene were used for dipping livestock. This was followed by Beaumont crude oil. Arsenical dips were introduced in 1911 and...

28

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

29

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

30

Caffeine, a naturally occurring acaricide.  

PubMed

Since caffeine is a plant alkaloid that has been described as a naturally occurring insecticide, its acaricidal effect on Dermatophagoides pteronyssinus (Dp) was investigated. Twelve cultures were established by adding 30 Dp to 200 mg of Tetramin fish food and brewer's yeast (8:2 ratio); six cultures were treated with 20 mg of finely ground caffeine. All 12 cultures were incubated at 75% relative humidity, 25 degrees C, and observed during 8 weeks. Live mites were then counted under a stereoscope, cultures were extracted, and supernatants were analyzed for Der p I and Der f I allergen content with a two-site monoclonal RIA. Live mite counts in untreated cultures varied from 146 to 274 (215 +/- 47.1), and in caffeine-treated cultures from 0 to 3 (1 +/- 1.2; p less than or equal to 0.0001). Der p I concentrations in untreated cultures varied from 588 to 9000 ng/gm (3138.3 +/- 2990.8 ng/gm), and in caffeine-treated cultures from 52 to 117 ng/gm (78 +/- 23.8 ng/gm; p less than or equal to 0.01). Der p I was not detected in the food media or caffeine; Der f I was not detected in any of the cultures. Results demonstrate that caffeine inhibits mite growth and allergen production. PMID:1991914

Russell, D W; Fernández-Caldas, E; Swanson, M C; Seleznick, M J; Trudeau, W L; Lockey, R F

1991-01-01

31

Characterization of Streptomyces scabies mutants deficient in melanin biosynthesis.  

PubMed

Streptomyces scabies, a causal agent of common scab, produces both melanin and a secondary metabolite called thaxtomin A. To establish a possible relation between melanin and thaxtomin A production in S. scabies, we carried out N-methyl-N'-nitro-N-nitrosoguanidine (NTG) mutagenesis and isolated 11 melanin-negative mutants of S. scabies EF-35. These mutants were characterized for thaxtomin A production, pathogenicity, sporulation, and stress resistance. Nine of these mutants showed a significant reduction in thaxtomin A production when compared with the wild strain. However, only a few mutants exhibited a reduced level of virulence or a loss in their ability to induce common scab symptoms on potato tubers. Other pleiotrophic effects, such as higher sensitivity to heavy metals and incapacity to sporulate under certain stress conditions, were also associated with a deficiency in melanin production. PMID:15644924

Beauséjour, Julie; Beaulieu, Carole

2004-09-01

32

Can house dust mite-triggered atopic dermatitis be alleviated using acaricides?  

PubMed

House dust mite (HDM) allergens are the most important triggers for atopic dermatitis. Reducing exposure to these allergens may alleviate clinical symptoms. Chemicals with acaricidal activity have been used to treat upholstered furniture, carpets and bedding with the aim to reduce HDM allergen exposure. These chemicals, by reducing HDM, can decrease the concentration of mite allergens in dust but improvements in clinical symptoms are not always apparent. Clinical improvement is more likely to occur if bedding has been treated rather than carpets and upholstery. Future control strategies should be aimed at treating bedding. Permethrin is a very efficient killer of mites. It is used topically to treat scabies and head lice and is impregnated in bed nets to prevent mosquito bites. Even when applied to the skin in high concentrations, it has a very low toxicity in humans and other mammals. Permethrin-impregnated bedding may prove to be the best control method in the treatment of HDM allergen-triggered atopic conditions. PMID:9274618

Cameron, M M

1997-07-01

33

Acaricide, Fungicide and Drug Interactions in Honey Bees (Apis mellifera)  

PubMed Central

Background Chemical analysis shows that honey bees (Apis mellifera) and hive products contain many pesticides derived from various sources. The most abundant pesticides are acaricides applied by beekeepers to control Varroa destructor. Beekeepers also apply antimicrobial drugs to control bacterial and microsporidial diseases. Fungicides may enter the hive when applied to nearby flowering crops. Acaricides, antimicrobial drugs and fungicides are not highly toxic to bees alone, but in combination there is potential for heightened toxicity due to interactive effects. Methodology/Principal Findings Laboratory bioassays based on mortality rates in adult worker bees demonstrated interactive effects among acaricides, as well as between acaricides and antimicrobial drugs and between acaricides and fungicides. Toxicity of the acaricide tau-fluvalinate increased in combination with other acaricides and most other compounds tested (15 of 17) while amitraz toxicity was mostly unchanged (1 of 15). The sterol biosynthesis inhibiting (SBI) fungicide prochloraz elevated the toxicity of the acaricides tau-fluvalinate, coumaphos and fenpyroximate, likely through inhibition of detoxicative cytochrome P450 monooxygenase activity. Four other SBI fungicides increased the toxicity of tau-fluvalinate in a dose-dependent manner, although possible evidence of P450 induction was observed at the lowest fungicide doses. Non-transitive interactions between some acaricides were observed. Sublethal amitraz pre-treatment increased the toxicity of the three P450-detoxified acaricides, but amitraz toxicity was not changed by sublethal treatment with the same three acaricides. A two-fold change in the toxicity of tau-fluvalinate was observed between years, suggesting a possible change in the genetic composition of the bees tested. Conclusions/Significance Interactions with acaricides in honey bees are similar to drug interactions in other animals in that P450-mediated detoxication appears to play an important role. Evidence of non-transivity, year-to-year variation and induction of detoxication enzymes indicates that pesticide interactions in bees may be as complex as drug interactions in mammals. PMID:23382869

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

2013-01-01

34

The incidence of molluscum contagiosum, scabies and lichen planus.  

PubMed Central

We aimed to describe the incidence of new episodes of molluscum contagiosum, scabies and lichen planus presenting to general practitioners in England and Wales. We examined data collected in a sentinel practice network (the Weekly Returns Service of the Royal College of General Practitioners) in which about half a million persons were observed each year over the period 1994-2003. The incidence of molluscum contagiosum in males was 243/100,000 person-years and in females 231; of scabies, males 351, females 437; of lichen planus, males 32, females 37. Incidence varied by year and age. Ninety per cent of molluscum contagiosum episodes were reported in children aged 0-14 years, where incidence in 2000 (midpoint of a 6-year period of stable incidence) was 1265/100,000 (95% CI 1240-1290). Scabies affected all ages and annual incidence ranged between 233 (95% CI 220-246) in 2003 and 470 (95% CI 452-488) in 2000. Lichen planus occurred chiefly in persons aged over 45 years: incidence (all ages) ranged between 27 (95% CI 23-31) in 2003 and 43 (95% CI 37-49) in 1998. The relative risk of female to male incidence (all ages) of molluscum contagiosum was 0.95 (95% CI 0.91-0.99); of scabies 1.25 (95% CI 1.21-1.28); and of lichen planus 1.19 (95% CI 1.08-1.13). PMID:16274495

Pannell, R. S.; Fleming, D. M.; Cross, K. W.

2005-01-01

35

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

36

Streptomyces scabies 87-22 possesses a functional tomatinase.  

PubMed

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 alpha-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 alpha-tomatine and not potato glycoalkaloids or xylans. Tomatinase-null mutants were more sensitive to alpha-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 alpha-tomatine is not present during vegetative growth. Severities of disease for tomato seedlings affected by S. scabies 87-22 wild-type and DeltatomA1 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

2008-12-01

37

Unusual production of 5-Nitroanthranilic acid by streptomyces scabies  

Microsoft Academic Search

Examination of non-phytotoxic extracts associated with the in vitro production of thaxtomin A by various Streptomyces scabies isolates consistently yielded a nitroaromatic compound that was characterized by spectral and synthetic means as 5-nitroanthranilic acid (2-amino-5-nitrobenzoic acid). Investigations examining its possible role in the biosynthesis of thaxtomin A were inconclusive.

R. R King; C. H Lawrence; L. A Calhoun

1998-01-01

38

Properties and actions of bridged diphenyl acaricides.  

PubMed Central

The properties and actions of the bridged diphenyl acaricides are discussed. These pesticides, which are more or less structurally related to DDT, were the first of the specific acaricides to be developed. They exhibit remarkable properties of specificity, being primarily toxic to phytophagous mites but of very low toxicity to most nontarget species, including insects, fish, birds, and mammals. Although many important facets of their broad mode of action are understood, virtually nothing is known of their primary mode of action or the underlying bases of their specificities. In most ways they are model compounds for integrated control and pest management activities and thus merit greater attention than they have received to elucidate the fundamentals underlying their unusual properties and actions. PMID:789071

March, R B

1976-01-01

39

Structural Mechanisms of Inactivation in Scabies Mite Serine Protease Paralogues  

SciTech Connect

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 {angstrom} and 2.0 {angstrom} 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.

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.; (Monash); (Queensland Inst. of Med. Rsrch.)

2009-08-07

40

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

41

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

42

Recommendation for the conservation of the name Streptomyces scabies. Request for an Opinion.  

PubMed

The primary streptomycete inciting common scab of potato was first legitimately described by Thaxter in 1892 as 'Oospora scabies', preserving the spelling of an epithet in use since 1846. The name Streptomyces scabies, dating to 1948, was revived in 1989, but changed to Streptomyces scabiei in 1997 to follow grammatical convention. Considering the long-established use and general recognition of 'scabies', it is proposed that the original epithet be conserved. PMID:17911322

Lambert, D H; Loria, R; Labeda, D P; Saddler, G S

2007-10-01

43

Risk factors for scabies among male soldiers in Pakistan: case-control study.  

PubMed

Being a preventable disease, good control of scabies can be achieved by identification of risk factors. During the 3-month period February 2006-April 2006 we carried out a case-control study on 200 patients with scabies and 200 controls to identify risk factors for scabies among male soldiers in Pakistan. We identified risk factors for the infestation using logisitic regression analysis. Itching in family/dormitory mates, infrequent bathing, infrequent changing of clothes, low education, sharing beds and being away from the barracks were identified as significant risk factors for scabies, while overcrowding, large family size and sharing of towels and hospitalisation were not. PMID:20214123

Raza, N; Qadir, S N R; Agha, H

2009-01-01

44

COMPARISON OF THE REPORDUCTIVE BIOLOGY BETWEEN ACARICIDE-RESISTANT AND ACARICIDE-SUSCEPTIBLE RHIPICEPHALUS (BOOPLILUS) MICROPLUS (ACARI:IXODIDAE)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The reproductive dynamics of an acaricide-susceptible strain (SUS) of Boophilus microplus were compared to strains of ticks resistant to organophosphate (OP), pyrethroid (P), or formamidine (F) acaricides to determine whether the acquisition of resistance caused a reduction in fitness. The SUS stra...

45

Preliminary study of effectiveness of aloe vera in scabies treatment.  

PubMed

In an open, non-comparative study carried out between August and December 2002 at the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria, 5 patients with scabies were successfully treated with crude gel of Aloe vera; thereafter the efficacy of the extract was compared with that of benzoate lotion among 30 patients. Sixteen patients were treated with Aloe vera and 14 patients had benzyl benzoate lotion. Itching was still present in 3 patients in the benzyl benzoate group and in 2 patients in the Aloe vera group after 2 courses of treatment. The scabietic lesions virtually disappeared in all of them. None of these patients had any noticeable side effects. It is concluded that Aloe vera gel is as effective as benzyl benzoate in the treatment of scabies. PMID:19274696

Oyelami, O A; Onayemi, A; Oyedeji, O A; Adeyemi, L A

2009-10-01

46

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

47

Elastosis Perforans Serpiginosa in Association with Scabies Mite  

PubMed Central

Elastosis perforans serpiginosa is a form of perforating dermatoses, which has a characteristic clinical presentation of grouped keratotic papules coalescing into serpiginous or annular configurations. The majority of elastosis perforans serpiginosa cases are idiopathic; however, various etiologies have been postulated for the pathogenesis of this syndrome. The authors present a unique case of elastosis perforans serpiginosa that developed focally secondary to a scabies mite. PMID:24155992

Frederickson, Julie; Griffith, Jack; Shitabata, Paul; Horowitz, David

2013-01-01

48

Pathogenicity of Streptomyces scabies on Potato Tubers cultured in vitro  

Microsoft Academic Search

IN potato breeding trials conducted here extensive investigations are required to determine the relative resistance of selected seedlings to the common scab disease caused by Streptomyces scabies (Thaxt.) Waksman and Henrici. The tissue-culture technique1,2 for establishing a ready source of aseptic tubers potentially offers a rapid and convenient method for indexing their resistance and for studies on the host-parasite interactions.

C. H. Lawrence; W. G. Barker

1963-01-01

49

Mutational analysis of the Streptomyces scabies esterase signal peptide  

Microsoft Academic Search

Ten site-directed mutations affecting the predicted 39-amino-acid signal peptide of the Streptomyces scabies esterase were used to examine start-codon usage and esterase secretion in S. lividans. The first of two in-frame AUG codons was preferred for translation initiation. Removal of 2 of the 4 positively charged\\u000a amino acids at the amino terminus of the signal peptide reduced esterase expression more

V. A. Hale; J. L. Schottel

1996-01-01

50

Pathogenicity of Streptomyces scabies Mutants Altered in Thaxtomin A Production.  

PubMed

ABSTRACT To investigate the role of thaxtomin A in the pathogenicity of Streptomyces scabies, mutants altered in thaxtomin A production were obtained by N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. Mutants of S. scabies EF-35 could be differentiated according to levels of thaxtomin production. Mutants M1, M8, and M19 produced 2 to 20 times less thaxtomin A in oat bran medium than did EF-35. M1 and M19 were deficient in tryptophan catabolism. Thaxtomin production was reduced by about 300 times in mutant M16, which was a glutamic acid auxotroph. No thaxtomin A was detected in M13 culture supernatant. This mutant had a normal growth rate, was prototrophic, and catabolized tryptophan. Pathogenicity of mutants was tested on radish and potato. Mutants M1, M8, and M19 were pathogenic but, in most cases, less virulent than EF-35. M13 and M16 were nonpathogenic. These results suggest that thaxtomin A is an important pathogenicity determinant in S. scabies. PMID:18944924

Goyer, C; Vachon, J; Beaulieu, C

1998-05-01

51

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

52

Acaricide residues in beeswax after conversion to organic beekeeping methods  

Microsoft Academic Search

Beekeepers interested in converting their honey farms to organic management must replace old combs with organic foundations.\\u000a The experiment described in this paper compares two methods of replacement of old combs, “fast” (5 combs per year) and “slow”\\u000a (2 combs per year), by measuring the levels of acaricide residues in the newly built combs. Tested acaricides were coumaphos\\u000a (Perizin and

Marco Lodesani; Cecilia Costa; Giorgia Serra; Roberto Colombo; Anna Gloria Sabatini

2008-01-01

53

Acaricidal effects of fenvalerate and cypermethrin against Rhipicephalus (Boophilus) annulatus.  

PubMed

The acaricidal effects of two most commonly used acaricides viz., fenvalerate and cypermethrin against Rhipicephalus (Boophilus) annulatus were studied using Adult Immersion Test (AIT). The LC50 values observed for fenvalerate and cypermethrin were 1570 ppm and 184 ppm respectively. The death of ticks was not an immediate process. Fenvalerate caused death only after 7 days while cypermethrin after 5 days of treatment. The eggs laid by treated ticks did not hatch at all concentrations tested. PMID:25382471

Ravindran, R; Ajith Kumar, K G; Suresh, N N; Amithamol, K K; Sunil, A R; Adarshkrishna, T P; Chithra, N D; Jyothimol, G; Ghosh, S; Juliet, S

2014-09-01

54

Scabies and Impetigo Prevalence and Risk Factors in Fiji: A National Survey  

PubMed Central

Background Scabies is recognised as a major public health problem in many countries, and is responsible for significant morbidity due to secondary bacterial infection of the skin causing impetigo, abscesses and cellulitis, that can in turn lead to serious systemic complications such as septicaemia, kidney disease and, potentially, rheumatic heart disease. Despite the apparent burden of disease in many countries, there have been few large-scale surveys of scabies prevalence or risk factors. We undertook a population-based survey in Fiji of scabies and impetigo to evaluate the magnitude of the problem and inform public health strategies. Methodology/Principal Findings A total of 75 communities, including villages and settlements in both urban and rural areas, were randomly selected from 305 communities across the four administrative divisions, and all residents in each location were invited to participate in skin examination by trained personnel. The study enrolled 10,887 participants. The prevalence of scabies was 23.6%, and when adjusted for age structure and geographic location based on census data, the estimated national prevalence was 18.5%. The prevalence was highest in children aged five to nine years (43.7%), followed by children aged less than five (36.5%), and there was also an indication of prevalence increasing again in older age. The prevalence of scabies was twice as high in iTaukei (indigenous) Fijians compared to Indo-Fijians. The prevalence of impetigo was 19.6%, with a peak in children aged five to nine years (34.2%). Scabies was very strongly associated with impetigo, with an estimated 93% population attributable risk. Conclusions As far as we are aware, this is the first national survey of scabies and impetigo ever conducted. We found that scabies occurs at high levels across all age groups, ethnicities, and geographical locations. Improved strategies are urgently needed to achieve control of scabies and its complications in endemic communities. PMID:25738499

Romani, Lucia; Koroivueta, Josefa; Steer, Andrew C.; Kama, Mike; Kaldor, John M.; Wand, Handan; Hamid, Mohammed; Whitfeld, Margot J.

2015-01-01

55

Dissecting the complete lipoprotein biogenesis pathway in Streptomyces scabies.  

PubMed

Following translocation, bacterial lipoproteins are lipidated by lipoprotein diacylglycerol transferase (Lgt) and cleaved of their signal peptides by lipoprotein signal peptidase (Lsp). In Gram-negative bacteria and mycobacteria, lipoproteins are further lipidated by lipoprotein N-acyl transferase (Lnt), to give triacylated lipoproteins. Streptomyces are unusual amongst Gram-positive bacteria because they export large numbers of lipoproteins via the twin arginine protein transport (Tat) pathway. Furthermore, some Streptomyces species encode two Lgt homologues and all Streptomyces species encode two homologues of Lnt. Here we characterize lipoprotein biogenesis in the plant pathogen Streptomyces scabies and report that lgt and lsp mutants are defective in growth and development while only moderately affected in virulence. Lipoproteins are lost from the membrane in an S. scabies lgt mutant but restored by expression of Streptomyces coelicolor lgt1 or lgt2 confirming that both encode functional Lgt enzymes. Furthermore, lipoproteins are N-acylated in Streptomyces with efficient N-acylation dependent on Lnt1 and Lnt2. However, deletion of lnt1 and lnt2 has no effect on growth, development or virulence. We thus present a detailed study of lipoprotein biogenesis in Streptomyces, the first study of Lnt function in a monoderm bacterium and the first study of bacterial lipoproteins as virulence factors in a plant pathogen. PMID:21477129

Widdick, David A; Hicks, Matthew G; Thompson, Benjamin J; Tschumi, Andreas; Chandra, Govind; Sutcliffe, Iain C; Brülle, Juliane K; Sander, Peter; Palmer, Tracy; Hutchings, Matthew I

2011-06-01

56

Infection of potato tubers by common scab (Streptomyces scabies) during brief periods when soil is drying  

Microsoft Academic Search

Plots of chitted and unchittedMajestic seed planted in soil naturally infested withStreptomyces scabies, were trickle irrigated to prevent infection except during 5, 10 or 15 days from when plants from unchitted seed began to form tubers.

D. H. Lapwood; T. F. Hering

1968-01-01

57

4-Nitrotrypophans associated with the in vitro production of thaxtomin A by Streptomyces scabies  

Microsoft Academic Search

Non-phytotoxic exudates associated with the in vitro production of thaxtomin A by Streptomyces scabies yielded two 4-nitrotryptophan derivatives, N-acetyl-4-nitrotryptophan and N-methyl-4-nitrotryptophan.

Russell R. King; C. Harold Lawrence

1995-01-01

58

Soil moisture and the infection of young potato tubers by Streptomyces scabies (common scab)  

Microsoft Academic Search

Majestic potatoes planted in soil naturally infested withStreptomyces scabies were trickle irrigated to prevent infection of the tubers except during consecutive 7-day periods in the first eight weeks when tubers were developing (28 May to 23 July).

D. H. Lapwood; T. F. Hering

1970-01-01

59

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

60

A Tractable Experimental Model for Study of Human and Animal Scabies  

PubMed Central

Background Scabies 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 has led to extreme levels of acute rheumatic fever and rheumatic heart disease in Australia's Indigenous communities. In addition, emerging resistance to currently available therapeutics emphasizes the need to identify potential targets for novel chemotherapeutic and/or immunological intervention. Scabies research has been severely limited by the availability of parasites, and scabies remains a truly neglected infectious disease. We report development of a tractable model for scabies in the pig, Sus domestica. Methodology/Principal Findings Over five years and involving ten independent cohorts, we have developed a protocol for continuous passage of Sarcoptes scabiei var. suis. To increase intensity and duration of infestation without generating animal welfare issues we have optimised an immunosuppression regimen utilising daily oral treatment with 0.2mg/kg dexamethasone. Only mild, controlled side effects are observed, and mange infection can be maintained indefinitely providing large mite numbers (>6000 mites/g skin) for molecular-based research on scabies. In pilot experiments we explore whether any adaptation of the mite population is reflected in genetic changes. Phylogenetic analysis was performed comparing sets of genetic data obtained from pig mites collected from naturally infected pigs with data from pig mites collected from the most recent cohort. Conclusions/Significance A reliable pig/scabies animal model will facilitate in vivo studies on host immune responses to scabies including the relations to the associated bacterial pathogenesis and more detailed studies of molecular evolution and host adaption. It is a most needed tool for the further investigation of this important and widespread parasitic disease. PMID:20668508

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

2010-01-01

61

Scabies among primary schoolchildren in Egypt: sociomedical environmental study in Kafr El-Sheikh administrative area  

PubMed Central

Background/objectives Scabies is a major global public health issue that might affect people from all socioeconomic levels. The primary contributing factors in contracting scabies seem to be poverty and overcrowded living conditions. Scabies often spreads among schoolchildren quite rapidly, owing to their close contact and overcrowding within the schools. However, limited information is available about its risk factors and the socioeconomic correlates among schoolchildren in Egypt. This study aimed to assess the prevalence of scabies and its risk factors among primary schoolchildren in Kafr El-Sheikh administrative area, Egypt. Methods This cross-sectional descriptive study was performed on primary schoolchildren in urban and rural areas of Kafr El-Sheikh administrative area. A predesigned questionnaire was used for data collection from the randomly selected 2,104 children, and clinical dermatological examination was done for them. Results Out of 2,104 children studied, there were 92 cases of scabies with a prevalence of 4.4%. The prevalence of scabies infestation in male students was 3.9%, while it was 4.8% in females, with no statistical significance. The results showed significant variations in the risk of scabies infestation by factors such as residence, paternal education and occupation, maternal education, sleeping with others, having animals at home, dealing with animals outside the house, type of building for living, family history of itchy rash, and sharing clothes with others. Conclusion In our community, scabies is still an important health problem affecting schoolchildren, especially in rural areas. It is characterized by a complex web of causation, particularly poor living conditions and low level of parents’ education.

Hegab, Doaa Salah; Kato, Abdullah Mahfouz; Kabbash, Ibrahim Ali; Dabish, Ghada Maged

2015-01-01

62

Relation of potato tuber growth and skin maturity to infection by common scab, Streptomyces scabies  

Microsoft Academic Search

Summary  Cut surfaces of tuber tissue of either resistant or susceptible varieties permitted abundant, macroscopically visible growth\\u000a ofS. scabies after being autoclaved or fumigated with propylene oxide. Sparse aerial mycelium developed on freshly cut, washed tuber surfaces.\\u000a In contrast, macroscopically visible growth ofS. scabies was prevented by intact skin surfaces of mature tubers which had been washed only, or autoclaved, or

W. J. Hooker; O. T. Page

1960-01-01

63

Phytotoxin Production and Aerial Mycelium Formation by Streptomyces scabies and S . acidiscabies in Vitro  

Microsoft Academic Search

  Culture conditions (pH, Ca2+, phosphate, and temperature) on phytotoxin production (thaxtomin A and concanamycins A and B) and aerial mycelium formation\\u000a were examined for two strains each of Streptomyces scabies and S. acidiscabies. Thaxtomin production decreased at pH 7.5 and increased at 15°C in S. scabies and increased at 30 mM phosphate in S. acidiscabies. Concanamycin production was stimulated by

Masahiro NATSUME; Mizuto TAKI; Nobuya TASHIRO; Hiroshi ABE

2001-01-01

64

Effect of potato suberin on Streptomyces scabies proteome.  

PubMed

Two-dimensional (2D) PAGE was used to detect proteins induced in Streptomyces scabies by potato suberin, a lipidic plant polymer. Nineteen up-regulated proteins were excised from 2D gels and analysed by N-terminal sequencing or tandem mass spectrometry (MS/MS). Four of the up-regulated proteins could be linked to the bacterial response to stress (AldH, GroES, TerD and LexA). Specific metabolic pathways seemed to be activated in the presence of suberin, as shown by the increased expression of specific transporters and of enzymes related not only to glycolysis, but also to nucleotide and amino acid metabolism. Suberin also appeared to influence secondary metabolism as it also caused the overproduction of the BldK proteins that are known to be involved in differentiation and secondary metabolism. PMID:19019004

Lauzier, Annie; Simao-Beaunoir, Anne-Marie; Bourassa, Sylvie; Poirier, Guy G; Talbot, Brian; Beaulieu, Carole

2008-11-01

65

Mutational analysis of the Streptomyces scabies esterase signal peptide.  

PubMed

Ten site-directed mutations affecting the predicted 39-amino-acid signal peptide of the Streptomyces scabies esterase were used to examine start-codon usage and esterase secretion in S. lividans. The first of two in-frame AUG codons was preferred for translation initiation. Removal of 2 of the 4 positively charged amino acids at the amino terminus of the signal peptide reduced esterase expression more than 100-fold; however, deletion of all 4 charged residues reduced expression by only 2- to 5-fold. Deletion of 4 or 8 amino acids from the hydrophobic core of the signal peptide reduced esterase production more than 200-fold, and a signal peptide processing site deletion completely disrupted esterase expression. For all constructs in which a mutation in the signal sequence decreased esterase production, esterase mRNA levels were also reduced, suggesting that a defect in secretion or processing affected esterase transcript abundance. PMID:8920191

Hale, V A; Schottel, J L

1996-03-01

66

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

67

Detection of living Sarcoptes scabiei larvae by reflectance mode confocal microscopy in the skin of a patient with crusted scabies  

NASA Astrophysics Data System (ADS)

Scabies is an intensely pruritic disorder induced by a delayed type hypersensitivity reaction to infestation of the skin by the mite Sarcoptes scabiei. The diagnosis of scabies is established clinically and confirmed by identifying mites or eggs by microscopic examination of scrapings from the skin or by surface microscopy using a dermatoscope. Reflectance-mode confocal microscopy is a novel technique used for noninvasive imaging of skin structures and lesions at a resolution compatible to that of conventional histology. Recently, the technique was employed for the confirmation of the clinical diagnosis of scabies. We demonstrate the first ever documentation of a larva moving freely inside the skin of a patient infected with scabies.

Levi, Assi; Mumcuoglu, Kosta Y.; Ingber, Arieh; Enk, Claes D.

2012-06-01

68

Genetic basis and impact of tick acaricide resistance  

Technology Transfer Automated Retrieval System (TEKTRAN)

Acaricide resistance in the cattle tick, Boophilus microplus, has been studied for the last 20 years from the toxicology, metabolic, and genomic points of view, however, only few methods for molecular detection of resistance have been developed. Despite the relatively poor sensitivity for resistance...

69

Monitoring of resistance or susceptibility of adults and larvae of Amblyomma cajennense (Acari: Ixodidae) to synthetic acaricides in Goiás, Brazil.  

PubMed

Amblyomma cajennense or the Cayenne tick is a three-host ixodid tick species of low parasitic specificity that is the principal vector of Brazilian spotted fever. The primary objective of this study was to evaluate the possible development of resistance by adult specimens of A. cajennense to deltamethrin, a synthetic pyrethroid insecticide and the principal miticide/acaricide commercially available in the region. The second objective was to monitor the susceptibility and/or resistance of larvae of this species to 12 synthetic acaricide formulations selected from the principal pesticides available in Goiás for the control of ticks. Unfed male and female adult specimens of A. cajennense were collected from leaves of bushes along a nature trail in the municipality of Caldas Novas, Goiás, Brazil. They were submitted to immersion in the highest recommended dose of deltamethrin and subsequently, were placed in contact with filter paper impregnated with the substance. The toxicological effects caused by the insecticide were observed every 6 h over a 36 h period. To obtain larvae, engorged females of A. cajennense were collected from naturally infested horses that had been free of acaricidal residue for at least 45 days, in farms situated in five different municipalities in the state (Caldas Novas, Hidrolândia, Goiás, Terezópolis and Goiânia). The larvae were exposed to different concentrations of 12 commercially available acaricidal formulations using the larval packet test (LPT) method. The control groups were treated with distilled water alone. The bioassays were performed in quadruplicate at a temperature of 27 °C, relative air humidity > 80% and 12 h light/dark cycles. The mean percentage of mortality MX was 72.6% in the adult specimens after 24 h of exposure to the dose of deltamethrin recommended by the manufacturer, characterizing a status of resistance. MX of 82, 89, 89.6 and 90% of the larvae were obtained, respectively, for deltamethrin, cypermethrin + piperonyl butoxide (PBO), amitraz and permethrin, characterizing a status of probable resistance of the larvae to these acaricides. No significant mortality was found in the control groups. PMID:20976616

Freitas, Edméia de Paula e Souza; Zapata, Marco Túlio Antônio Garcia; Fernandes, Fernando de Freitas

2011-02-01

70

GENETICALLY DISTINCT DOG-DERIVED AND HUMAN-DERIVED SARCOPTES SCABIEI IN SCABIES-ENDEMIC COMMUNITIES IN NORTHERN AUSTRALIA  

Microsoft Academic Search

Abstract. Overcrowding is a significant factor contributing to endemic infection with Sarcoptes scabiei in human and animal populations. However, since scabies mites from different host species are indistinguishable morphologi- cally, it is unclear whether people can be infected from scabies-infested animals. Molecular fingerprinting was done using three S. scabiei-specific single locus hypervariable microsatellite markers, with a combined total of 70

Shelley F. Walton; Jodie Low Choy; Annie Bonson; Antony Valle; James M Cbroom; David Taplin; Larry Arlian; John D. Mathews; Bart Currie; David J. Kemp

71

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

72

Acaricide resistance in cattle ticks and approaches to its management: the state of play.  

PubMed

Cattle ticks are an important constraint on livestock production, particularly in tropical and subtropical areas. Use of synthetic acaricides is the primary method of tick control; therefore, it would be imperative to develop strategies to preserve the efficacy of existing acaricides. This paper summarizes the status of acaricide resistance in cattle ticks from different parts of the world and reviews modes of action of currently used acaricides, mechanism of resistance development, contributory factors for the development and spread of resistance, management of resistant strains and strategies to prolong the effect of the available acaricides. Use of vaccines, synthetic and botanical acaricides and educating farmers about recommended tick control practices are discussed, along with the integration of currently available options for the management of drug resistance and, ultimately, the control of cattle ticks. PMID:24709006

Abbas, Rao Z; Zaman, Muhammad Arfan; Colwell, Douglas D; Gilleard, John; Iqbal, Zafar

2014-06-16

73

The Cellobiose Sensor CebR Is the Gatekeeper of Streptomyces scabies Pathogenicity  

PubMed Central

ABSTRACT A relatively small number of species in the large genus Streptomyces are pathogenic; the best characterized of these is Streptomyces scabies. The pathogenicity of S. scabies strains is dependent on the production of the nitrated diketopiperazine thaxtomin A, which is a potent plant cellulose synthesis inhibitor. Much is known about the genetic loci associated with plant virulence; however, the molecular mechanisms by which S. scabies triggers expression of thaxtomin biosynthetic genes, beyond the pathway-specific activator TxtR, are not well understood. In this study, we demonstrate that binding sites for the cellulose utilization repressor CebR occur and function within the thaxtomin biosynthetic cluster. This was an unexpected result, as CebR is devoted to primary metabolism and nutritive functions in nonpathogenic streptomycetes. In S. scabies, cellobiose and cellotriose inhibit the DNA-binding ability of CebR, leading to an increased expression of the thaxtomin biosynthetic and regulatory genes txtA, txtB, and txtR. Deletion of cebR results in constitutive thaxtomin A production and hypervirulence of S. scabies. The pathogenicity of S. scabies is thus under dual direct positive and negative transcriptional control where CebR is the cellobiose-sensing key that locks the expression of txtR, the key necessary to unlock the production of the phytotoxin. Interestingly, CebR-binding sites also lie upstream of and within the thaxtomin biosynthetic clusters in Streptomyces turgidiscabies and Streptomyces acidiscabies, suggesting that CebR is most likely an important regulator of virulence in these plant-pathogenic species as well. PMID:25714708

Francis, Isolde M.; Jourdan, Samuel; Fanara, Steven; Loria, Rosemary

2015-01-01

74

A Novel Clinical Grading Scale to Guide the Management of Crusted Scabies  

PubMed Central

Background Crusted scabies, or hyperinfestation with Sarcoptes scabiei, occurs in people with an inadequate immune response to the mite. In recent decades, data have emerged suggesting that treatment of crusted scabies with oral ivermectin combined with topical agents leads to lower mortality, but there are no generally accepted tools for describing disease severity. Here, we describe a clinical grading scale for crusted scabies and its utility in real world practice. Methodology/Principal Findings In 2002, Royal Darwin Hospital (RDH), a hospital in tropical Australia developed and began using a clinical grading scale to guide the treatment of crusted scabies. We conducted a retrospective observational study including all episodes of admission to RDH for crusted scabies during the period October 2002–December 2010 inclusive. Patients who were managed according to the grading scale were compared with those in whom the scale was not used at the time of admission but was calculated retrospectively. There were 49 admissions in 30 patients during the study period, of which 49 (100%) were in Indigenous Australians, 29 (59%) were male and the median age was 44.1 years. According to the grading scale, 8 (16%) episodes were mild, 24 (49%) were moderate, and 17 (35%) were severe. Readmission within the study period was significantly more likely with increasing disease severity, with an odds ratio (95% CI) of 12.8 (1.3–130) for severe disease compared with mild. The patients managed according to the grading scale (29 episodes) did not differ from those who were not (20 episodes), but they received fewer doses of ivermectin and had a shorter length of stay (11 vs. 16 days, p?=?0.02). Despite this the outcomes were no different, with no deaths in either group and a similar readmission rate. Conclusions/Significance Our grading scale is a useful tool for the assessment and management of crusted scabies. PMID:24069468

Tong, Steven Y. C.; Walton, Shelley F.; Currie, Bart J.

2013-01-01

75

Transcription and induction profiles of two esterase genes in susceptible and acaricide-resistant Tetranychus cinnabarinus  

Microsoft Academic Search

The carmine spider mite Tetranychus cinnabarinus is the most serious of crop mite pests in China. Their ability to rapidly develop resistance to acaricides has caused difficulty in controlling this mite. In this study, the molecular mechanism of acaricide resistance associated with esterase genes TCE1 and TCE2 was investigated in susceptible and acaricide-resistant strains of T. cinnabarinus. The quantitative real-time

Ya-ning Feng; Jin Yan; Wei Sun; Shu Zhao; Wen-Cai Lu; Ming Li; Lin He

2011-01-01

76

Prospective Study in a Porcine Model of Sarcoptes scabiei Indicates the Association of Th2 and Th17 Pathways with the Clinical Severity of Scabies  

PubMed Central

Background Understanding of scabies immunopathology has been hampered by the inability to undertake longitudinal studies in humans. Pigs are a useful animal model for scabies, and show clinical and immunologic changes similar to those in humans. Crusted scabies can be readily established in pigs by treatment with the glucocorticoid dexamethasone (Dex). Methodology/ Principal Findings Prospective study of 24 pigs in four groups: a) Scabies+/Dex+, b) Scabies+/Dex-, c) Scabies-/Dex+ and d) Scabies-/Dex-. Clinical symptoms were monitored. Histological profiling and transcriptional analysis of skin biopsies was undertaken to compare changes in cell infiltrates and representative cytokines. A range of clinical responses to Sarcoptes scabiei were observed in Dex treated and non-immunosuppressed pigs. An association was confirmed between disease severity and transcription of the Th2 cytokines IL-4 and IL-13, and up-regulation of the Th17 cytokines IL-17 and IL-23 in pigs with crusted scabies. Immunohistochemistry revealed marked infiltration of lymphocytes and mast cells, and strong staining for IL-17. Conclusions/ Significance While an allergic Th2 type response to scabies has been previously described, these results suggest that IL-17 related pathways may also contribute to immunopathology of crusted scabies. This may lead to new strategies to protect vulnerable subjects from contracting recurrent crusted scabies. PMID:25730203

Mounsey, Kate E.; Murray, Hugh C.; Bielefeldt-Ohmann, Helle; Pasay, Cielo; Holt, Deborah C.; Currie, Bart J.; Walton, Shelley F.; McCarthy, James S.

2015-01-01

77

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

78

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

79

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

80

Recommendation for the conservation of the name Streptomyces scabies. Request for an opinion.  

Technology Transfer Automated Retrieval System (TEKTRAN)

The taxonomic name of the pathogenic Streptomyces species that causes potato scab was changed in 1997 from Streptomyces scabies to Streptomyces scabiei in order to correct improper usage of Latin. The original species name had been in the literature since 1914 and this created confusion among resea...

81

Fatty Acid and Protein Profiles of Streptomyces scabies Strains Isolated in Eastern Canada  

Microsoft Academic Search

Fatty acid composition was assessed for 31 pathogenic and nonpathogenic strains phenotypically related to Streptomyces scabies and isolated in eastern Canada. The profiles of these strains consisted of 12 to 17 fatty acids, most of which were saturated is0 and anteiso acids. The 31 strains were clustered into two groups within a Euclidian distance of 25. Members in the first

ERIC PARADIS; CLAUDIA GOYER; NANCY C. HODGE; RICHARD HOGUE; ROBERT E. STALL; CAROLE BEAULIEU

1994-01-01

82

Thaxtomin A production and virulence are controlled by several bld gene global regulators in Streptomyces scabies.  

PubMed

Streptomyces scabies is the main causative agent of common scab disease, which leads to significant annual losses to potato growers worldwide. The main virulence factor produced by S. scabies is a phytotoxic secondary metabolite called thaxtomin A, which functions as a cellulose synthesis inhibitor. Thaxtomin A production is controlled by the cluster-situated regulator TxtR, which activates expression of the thaxtomin biosynthetic genes in response to cello-oligosaccharides. Here, we demonstrate that at least five additional regulatory genes are required for wild-type levels of thaxtomin A production and plant pathogenicity in S. scabies. These regulatory genes belong to the bld gene family of global regulators that control secondary metabolism or morphological differentiation in Streptomyces spp. Quantitative reverse-transcriptase polymerase chain reaction showed that expression of the thaxtomin biosynthetic genes was significantly downregulated in all five bld mutants and, in four of these mutants, this downregulation was attributed to the reduction in expression of txtR. Furthermore, all of the mutants displayed reduced expression of other known or predicted virulence genes, suggesting that the bld genes may function as global regulators of virulence gene expression in S. scabies. PMID:24678834

Bignell, Dawn R D; Francis, Isolde M; Fyans, Joanna K; Loria, Rosemary

2014-08-01

83

Hopanoids are not essential for growth of Streptomyces scabies 87-22.  

PubMed

Hopanoids are triterpenoic, pentacyclic compounds that are structurally similar to sterols, which are required for normal cell function in eukaryotes. Hopanoids are thought to be an important component of bacterial cell membranes because they control membrane fluidity and diminish passive diffusion of ions, and a few taxons modulate their hopanoid content in response to environmental stimuli. However, to our knowledge, mutational studies to assess the importance of hopanoids in bacterial physiology have never been performed. Genome sequencing of the potato scab pathogen, Streptomyces scabies 87-22, revealed a hopanoid biosynthetic gene cluster (HBGC) that is predicted to synthesize hopene and aminotrihydroxybacteriohopane products. Hopene was produced by fully sporulated cultures of S. scabies on solid ISP4 (International Streptomyces Project 4) medium as well as by submerged mycelia grown in liquid minimal medium. The elongated hopanoid aminotrihydroxybacteriohopane was not detected under either growth condition. Transcription of the S. scabies HBGC was upregulated during aerial growth, which suggests a link between hopanoid production and morphological development. Functional analysis of the S. scabies Delta hop615-1 and Delta hop615-7 mutant strains, the first hopanoid mutants created in any bacterial taxon, revealed that hopanoids are not required for normal growth or for tolerance of ethanol, osmotic and oxidative stress, high temperature, or low pH. This suggests that hopanoids are not essential for normal streptomycete physiology. PMID:19502399

Seipke, Ryan F; Loria, Rosemary

2009-08-01

84

Effects of inoculum density and cultivar resistance on common scab of potato and population dynamics of Streptomyces scabies  

Microsoft Academic Search

The interaction ofStreptomyces scabies, causal agent of common scab, and its potato host was examined under scab-conducive conditions in the greenhouse. Three potato\\u000a cultivars with different levels of resistance to common scab were inoculated with four levels of two rifampin-resistant strains\\u000a ofS. scabies. In general, scab severity increased linearly with an increase in log10 of the inoculum, but both cultivar

Anthony P. Keinath; Rosemary Loria

1991-01-01

85

Survival and behavioural response to acaricides of the coconut mite predator Neoseiulus baraki.  

PubMed

The coconut mite, Aceria guerreronis Keifer, is a major pest of coconut palm in the world. The control of this pest species is done through acaricide applications at short time intervals. However, the predators of this pest may also be affected by acaricides. Among the predators of A. guerreronis, Neoseiulus baraki (Athias-Henriot) has potential for biological control. The objective of this study was to assess the effect of acaricides on the survival and behavior of N. baraki. The survivorship of N. baraki was recorded in surface-impregnated arenas. Choice and no-choice behavioral bioassays were carried out using a video tracking system to assess the walking behavior of the predator under acaricide exposure. Although all acaricides negatively affected the survival of N. baraki, chlorfenapyr and azadirachtin caused lower effect than the other acaricides. No significant differences in walking behavior were observed under exposure to fenpyroximate, chlorfenapyr and chlorpyrifos on fully-contaminated arenas. Azadirachtin and chlorpyrifos caused repellence. Irritability was observed for all acaricides, except for abamectin. Chlorfenapyr was the most suitable product for managing the coconut mite because of its low effect on survival and behavior of N. baraki. PMID:23224672

Lima, Debora B; Melo, José W S; Guedes, Raul N C; Siqueira, Herbert A A; Pallini, Angelo; Gondim, Manoel G C

2013-07-01

86

Effect of amino acids on thaxtomin A biosynthesis by Streptomyces scabies.  

PubMed

The regulatory effect of amino acids on the production of thaxtomin A, a phytotoxin produced by Streptomyces scabies, was investigated. Tryptophan had an important inhibitory effect on the toxin biosynthesis in all five strains of S. scabies tested. Two other aromatic amino acids (tyrosine and phenylalanine) also inhibited thaxtomin A biosynthesis, while aliphatic amino acids did not cause an important decline in thaxtomin A production. Methylation of tryptophan prevented or reduced the inhibitory effect on thaxtomin A biosynthesis. In spite of the inhibitory action of tryptophan and phenylalanine on thaxtomin A production, incorporation of these radiolabeled molecules into thaxtomin A confirmed that they are metabolic precursors for the biosynthesis of the phytotoxin. PMID:12030709

Lauzier, Annie; Goyer, Claudia; Ruest, Luc; Brzezinski, Ryszard; Crawford, Don L; Beaulieu, Carole

2002-04-01

87

Cloning and Expression of a Gene from Streptomyces scabies Encoding a Putative Pathogenicity Factor  

Microsoft Academic Search

We cloned a 9.4-kb DNA fragment from Streptomyces scabies ATCC 41973 that allows the nonpathogen Strep- tomyces lividans 66 TK24 to necrotize and colonize potato tuber slices and produce scab-like symptoms on potato minitubers. Deletion analysis demonstrated that activity was conferred by a 1.6-kb DNA region. Se- quence analysis of a 2.4-kb DNA fragment spanning the DNA region necessary for

RAGHIDA A. BUKHALID; ROSEMARY LORIA

1997-01-01

88

Isolation and characterization of two types of actinophage infecting Streptomyces scabies  

Microsoft Academic Search

Two types of actinophages, ?S and ?L, were isolated from soil samples by usingStreptomyces scabies, a potato scab pathogen, as indicator strain. The phages were partially characterized according to their physicochemical\\u000a properties, plaques and particles morphology, and their host range; this varied from narrow (for ?S) to wide (for ?L). The\\u000a adsorption rate constants of the ?S and ?L were

El-S. A. El-Sayed; G. El-Didamony; K. Mansour

2001-01-01

89

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

Microsoft Academic Search

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

CYR LEZIN DOUMBOU; VLADIMIR AKIMOV; CAROLE BEAULIEU

1998-01-01

90

Cloning and sequencing of a secY homolog from Streptomyces scabies  

Microsoft Academic Search

The complete DNA sequence of the Streptomyces scabies (Ss) secY homolog and partial sequences of adjacent upstream and downstream open reading frames (ORFs) have been determined. The nucleotide sequence of a 2-kb region predicts a polypeptide of 437 amino acids in length with homology to the SecY protein family. The Ss secY homolog lies upstream from a sequence that has

Valerie A. Hale; Isabel O'Brien; Janet L. Schottel

1995-01-01

91

The twin arginine protein transport pathway exports multiple virulence proteins in the plant pathogen Streptomyces scabies.  

PubMed

Summary Streptomyces scabies is one of a group of organisms that causes the economically important disease potato scab. Analysis of the S. scabies genome sequence indicates that it is likely to secrete many proteins via the twin arginine protein transport (Tat) pathway, including several proteins whose coding sequences may have been acquired through horizontal gene transfer and share a common ancestor with proteins in other plant pathogens. Inactivation of the S. scabies Tat pathway resulted in pleiotropic phenotypes including slower growth rate and increased permeability of the cell envelope. Comparison of the extracellular proteome of the wild type and DeltatatC strains identified 73 predicted secretory proteins that were present in reduced amounts in the tatC mutant strain, and 47 Tat substrates were verified using a Tat reporter assay. The DeltatatC strain was almost completely avirulent on Arabidopsis seedlings and was delayed in attaching to the root tip relative to the wild-type strain. Genes encoding 14 candidate Tat substrates were individually inactivated, and seven of these mutants were reduced in virulence compared with the wild-type strain. We conclude that the Tat pathway secretes multiple proteins that are required for full virulence. PMID:20487278

Joshi, Madhumita V; Mann, Stefan G; Antelmann, Haike; Widdick, David A; Fyans, Joanna K; Chandra, Govind; Hutchings, Matthew I; Toth, Ian; Hecker, Michael; Loria, Rosemary; Palmer, Tracy

2010-07-01

92

Benzyl benzoate moist powder: investigation of acaricidal [correction of acarical] activity in cultures and reduction of dust mite allergens in carpets.  

PubMed

Despite advances in the understanding of dust mites, it remains difficult to control exposure to mite allergens, and it is particularly difficult to reduce mites in fitted carpets or sofas. Several chemicals have been demonstrated to kill mites or denature mite allergens, and some of these chemicals have been investigated in carpets. Benzyl benzoate (BB), which has been widely used to kill scabies mites and is known to kill mites of the genus Dermatophagoides, has been used as a method of treating carpets. The present article describes experiments in the laboratory and in houses in testing two preparations of BB, a moist powder and a foam. The moist powder is composed of two ingredients, a wetted "inert" cellulose, which is designed to act as a cleaning agent, and the active BB adsorbed onto silicates. The active powder kills 90% of mites in culture within 12 hours and 100% in 24 hours, whereas the cellulose is not acaricidal. The moist-powder preparation was highly effective at killing D. farinae and D. pteronyssinus mites in the laboratory. In carpets the moist powder, applied for 12 hours with repeated brushing, was demonstrated to reduce the concentrations of group I and group II dust mite allergens in dust recovered at 1 month. This decrease in concentration could, in part, be explained by a persistent increased recovery of dust caused by residual white powder. However, when the recovery of group II allergens was calculated as the total allergen recovered, the decrease was highly significant at 2 weeks and 4 weeks after treatment (p less than 0.001). Application of the powder to carpets for 4 hours or of the foam to sofas was less effective. After 2 months the effect on mite antigen in carpets was still present, but some increase was apparent, suggesting that repeat application after 2 or 3 months would be necessary to control mite-allergen levels. PMID:1740584

Hayden, M L; Rose, G; Diduch, K B; Domson, P; Chapman, M D; Heymann, P W; Platts-Mills, T A

1992-02-01

93

The AraC/XylS regulator TxtR modulates thaxtomin biosynthesis and virulence in Streptomyces scabies.  

PubMed

Streptomyces scabies is the best studied of those streptomycetes that cause an economically important disease known as potato scab. The phytotoxin thaxtomin is made exclusively by these pathogens and is required for virulence. Here we describe regulation of thaxtomin biosynthesis by TxtR, a member of the AraC/XylS family of transcriptional regulators. The txtR gene is imbedded in the thaxtomin biosynthetic pathway and is located on a conserved pathogenicity island in S. scabies, S. turgidiscabies and S. acidiscabies. Thaxtomin biosynthesis was abolished and virulence was almost eliminated in the txtR deletion mutant of S. scabies 87.22. Accumulation of thaxtomin biosynthetic gene (txtA, txtB, txtC, nos) transcripts was reduced compared with the wild-type S. scabies 87.22. NOS-dependent nitric oxide production by S. scabies was also reduced in the mutant. The TxtR protein bound cellobiose, an inducer of thaxtomin production, and transcription of txtR and thaxtomin biosynthetic genes was upregulated in response to cellobiose. TxtR is the first example of an AraC/XylS family protein regulated by cellobiose. Together, these data suggest that cellobiose, the smallest oligomer of cellulose, may signal the availability of expanding plant tissue, which is the site of action of thaxtomin. PMID:17919290

Joshi, Madhumita V; Bignell, Dawn R D; Johnson, Evan G; Sparks, Jed P; Gibson, Donna M; Loria, Rosemary

2007-11-01

94

Scabies outbreaks in residential care homes: factors associated with late recognition, burden and impact. A mixed methods study in England.  

PubMed

Scabies is an important public health problem in residential care homes. Delayed diagnosis contributes to outbreaks, which may be prolonged and difficult to control. We investigated factors influencing outbreak recognition, diagnosis and treatment, and staff experiences of outbreak control, identifying areas for intervention. We carried out a semi-structured survey of managers, affected residents and staff of seven care homes reporting suspected scabies outbreaks in southern England over a 6-month period. Attack rates ranged from 2% to 50%, and most cases had dementia (37/39, 95%). Cases were diagnosed clinically by GPs (59%) or home staff (41%), none by dermatologists. Most outbreaks were attributable to avoidably late diagnosis of the index case. Participants reported considerable challenges in managing scabies outbreaks, including late diagnosis and recognition of outbreaks; logistically difficult mass treatment; distressing treatment processes and high costs. This study demonstrates the need for improved support for care homes in detecting and managing these outbreaks. PMID:25195595

Hewitt, K A; Nalabanda, A; Cassell, J A

2015-05-01

95

Enhancing the acaricide effect of thymol on larvae of the cattle tick Rhipicephalus microplus (Acari: Ixodidae) by solubilization in ethanol.  

PubMed

The aim of the present work was to propose a new method of solubilizing thymol for use as an acaricide and to evaluate the resulting product's efficacy on Rhipicephalus microplus larvae. Two experiments were performed, both employing the larval packet test to evaluate the potential of the solutions formulated. In the first experiment, R. microplus larvae were exposed to three new formulations: formulation 1-distilled water (70%) + ethanol (30%) + thymol (10.0 mg/ml); formulation 2-distilled water (50%) + ethanol (50%) + thymol (10.0 mg/ml); and formulation 3-distilled water (55%) + ethanol (40%) + DMSO (5%) + thymol (10.0 mg/ml). A control was prepared for each formulation (same formulations except thymol), and another control group was formed where the larvae did not receive any treatment. From the results obtained in the first experiment, the formulation with the best performance and cost-benefit relation was chosen and was tested at concentrations of 2.5, 5.0 and 10.0 mg/ml on larvae of this tick. In the first experiment, the mortality of the groups treated with thymol was greater than 95% for all three formulations, with significant differences (p?acaricide activity on cattle tick larvae. PMID:21779863

Scoralik, Márcio Goldner; Daemon, Erik; de Oliveira Monteiro, Caio Márcio; Maturano, Ralph

2012-02-01

96

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

97

Cloning and expression of a gene from Streptomyces scabies encoding a putative pathogenicity factor.  

PubMed

We cloned a 9.4-kb DNA fragment from Streptomyces scabies ATCC 41973 that allows the nonpathogen Streptomyces lividans 66 TK24 to necrotize and colonize potato tuber slices and produce scab-like symptoms on potato minitubers. Deletion analysis demonstrated that activity was conferred by a 1.6-kb DNA region. Sequence analysis of a 2.4-kb DNA fragment spanning the DNA region necessary for activity revealed three open reading frames (ORFs). The deduced amino acid sequence of ORF1, designated ORFtnp, showed high levels of identity with the first 233 amino acids of the putative transposases of the IS1164 elements from Rhodococcus rhodochrous (71%) and Mycobacterium bovis (68%), members of the Staphylococcus aureus IS256 family of transposases. No significant homologies to ORF2 and ORF3 were found in the nucleic acid and protein databases. ORFtnp is located 5' of ORF3. ORF2 is incomplete and is located 3' of ORF3. Subcloning of the individual ORFs demonstrated that ORF3, designated nec1, is sufficient for necrotizing activity in S. lividans 66 TK24. S. lividans 66 TK24 expressing nec1 does not produce thaxtomin A but produces an unidentified extracellular water-soluble compound that causes necrosis on potato tuber discs. The G+C content of nec1 suggests that it has moved horizontally from another genus. Southern analysis of ORFtnp and nec1 demonstrate that these genes are physically linked in Streptomyces strains, including S. scabies and Streptomyces acidiscabies strains, that are pathogenic on potato and that produce the phytotoxin thaxtomin A. These data suggest that nec1 may have been mobilized into S. scabies through a transposition event mediated by ORFtnp. PMID:9401037

Bukhalid, R A; Loria, R

1997-12-01

98

Acaricide resistance and strategies to mitigate economic impact of the southern cattle fever tick (Rhipicephalus microplus) on livestock production systems in the Americas  

Technology Transfer Automated Retrieval System (TEKTRAN)

BACKGROUND: The southern cattle fever tick (SCFT), Rhipicephalus microplus, is considered the most economically important external parasite of livestock worldwide. SCFT populations resistant to acaricides complicate efforts to enhance the productivity of livestock. Here, acaricide resistance is summ...

99

EVALUATION OF EFFICACY AND SAFETY OF ACARICIDES FOR CONTROL OF THE AFRICAN TORTOISE TICK (AMBLYOMMA MARMOREUM) ON LEOPARD TORTOISES (GEOCHELONE PARDALIS)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nine acaricides (amitraz, carbaryl, chlorpyrifos, cyfluthrin, fipronil, lindane, permethrin, phenothrin and pyrethrins) were studied for the efficacy in killing the African tortoise tick (Amblyomma marmoreum). Only four of the acaricides (chlorpyrifos, cyfluthrin, lindane and permethrin) produced 1...

100

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

101

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

102

Amblyomma cajennense (Acari: Ixodidae) tick populations susceptible or resistant to acaricides in the Mexican Tropics.  

PubMed

The objectives of the present study were: (i) to identify the frequency of cattle farms with a cohabitation of Amblyomma cajennense and Rhipicephalus microplus, (ii) to determine the status of susceptibility or resistance to acaricides used in Veracruz, Mexico, on A. cajennense populations and (iii) to identify factors associated with A. cajennense resistant to acaricides. Fifty farms were visited to determine the presence of ticks (A. cajennense and R. microplus) and to collect engorged A. cajennense individuals. From these, 24 A. cajennense populations were evaluated in resistance bioassays using discriminating doses of acaricides. The acaricides tested were organophosphates (chlorpiriphos, coumaphos and diazinon), pyrethroids (flumethrin, deltamethrin and cypermethrin), amidines (amitraz) and fipronil (a broad spectrum N-phenylpyrazole insecticide). A. cajennense infesting bovines were identified in 86% (43/50) of the farms visited, and 100% of the farms sampled (43/43) had cohabitation between R. microplus and A. cajennense. Of the farm owners or managers surveyed, 87.5% could not distinguish the morphological difference between tick genera. Populations of A. cajennense were 100%, 91.7% and 12.5% resistant to diazinon, coumaphos and chlorpyriphos (organophosphates), respectively, and 12.5% to amitraz, as were those susceptible to flumethrin and fipronil. In conclusions, populations of A. cajennense showed a high frequency of resistance to the organophosphates tested and to amitraz. Factors associated with the resistance to acaricides in A. cajennense were not identified. PMID:23827041

Alonso-Díaz, M A; Fernández-Salas, A; Martínez-Ibáñez, F; Osorio-Miranda, J

2013-10-18

103

Mitigation of Resistance Through Mixtures of Traditional Pesticides, Anti-tick Vaccines, and New Acaricides Developed by the Pharmaceutical Industry  

Technology Transfer Automated Retrieval System (TEKTRAN)

Over the past 70 years, the southern cattle tick, Rhipicephalus (Boophilus) microplus, has developed resistance to every acaricide available for its control. Recently, populations of R. microplus have evolved simultaneous resistance to multiple classes of acaricides. These multi-resistant population...

104

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

105

Acaricide resistance status in Indian isolates of Hyalomma anatolicum.  

PubMed

The multi host tick, Hyalomma anatolicum, is the commonest Hyalomma species in India and cattle serves as the main host of this species. A study to evaluate the acaricide resistance of H. anatolicum to deltamethrin, cypermethrin and diazinon was conducted in 20 areas located in three agro climatic regions known to have abundance of the species. Results obtained by the "larval packet test" (LPT) showed a low grade resistance (level-I, RF <5) in the tick species to both deltamethrin and cypermethrin in 10 areas and higher grade resistance (level-II, RF <25) to deltamethrin in one area, where intensive use of synthetic pyrethroids are practiced for tick control. Low grade resistance to diazinon (level I) was recorded in six areas where organophosphates compounds are extensively used for agricultural practices allowing increased exposure of the moulting instars of the ticks to these chemicals. Biochemical analysis of the samples suggested involvement of esterase and alterations of acetylcholinesterase in the resistance mechanisms. PMID:22760859

Shyma, K P; Kumar, Sachin; Sharma, Anil Kumar; Ray, D D; Ghosh, S

2012-12-01

106

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

107

Selection and characterization of microorganisms utilizing thaxtomin A, a phytotoxin produced by streptomyces scabies  

PubMed

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 gamma 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; Akimov; Beaulieu

1998-11-01

108

The AraC/XylS regulator TxtR modulates Thaxtomin Biosynthesis and Virulence in Streptomyces scabies  

Technology Transfer Automated Retrieval System (TEKTRAN)

Streptomyces scabies is the best studied of those streptomycetes that cause an economically important disease known as potato scab. The phytotoxin thaxtomin is made exclusively by these pathogens and is required for virulence. Here we describe regulation of thaxtomin biosynthesis by TxtR, a member...

109

Streptomyces scabies 87-22 contains a coronafacic acid-like biosynthetic cluster that contributes to plant-microbe interactions.  

PubMed

Plant-pathogenic Streptomyces spp. cause scab disease on economically important root and tuber crops, the most important of which is potato. Key virulence determinants produced by these species include the cellulose synthesis inhibitor, thaxtomin A, and the secreted Nec1 protein that is required for colonization of the plant host. Recently, the genome sequence of Streptomyces scabies 87-22 was completed, and a biosynthetic cluster was identified that is predicted to synthesize a novel compound similar to coronafacic acid (CFA), a component of the virulence-associated coronatine phytotoxin produced by the plant-pathogenic bacterium Pseudomonas syringae. Southern analysis indicated that the cfa-like cluster in S. scabies 87-22 is likely conserved in other strains of S. scabies but is absent from two other pathogenic streptomycetes, S. turgidiscabies and S. acidiscabies. Transcriptional analyses demonstrated that the cluster is expressed during plant-microbe interactions and that expression requires a transcriptional regulator embedded in the cluster as well as the bldA tRNA. A knockout strain of the biosynthetic cluster displayed a reduced virulence phenotype on tobacco seedlings compared with the wild-type strain. Thus, the cfa-like biosynthetic cluster is a newly discovered locus in S. scabies that contributes to host-pathogen interactions. PMID:20064060

Bignell, Dawn R D; Seipke, Ryan F; Huguet-Tapia, José C; Chambers, Alan H; Parry, Ronald J; Loria, Rosemary

2010-02-01

110

Acaricidal activity of extracts from Adonis coerulea Maxim. against Psoroptes cuniculi in vitro and in vivo.  

PubMed

The acaricidal activity of Adonis coerulea extracts was investigated against Psoroptes cuniculi. The aqueous, methanol, acetic ether and petroleum ether extracts all showed marked acaricidal activity in vitro. Especially, the acetic ether extract possessed strong toxicity against mites in vitro with LT50 values 0.743 h, 2.730 h, 5.919 h and 22.536 h at concentrations of 500, 250, 125 and 62.5 mg/ml, respectively. At the same time, the acetic ether extract showed the best effectiveness topically to infested rabbits in vivo. After three times treatment, at the day 20, rabbits treated with A. coerulea extract were observed only small scabs or secretions in ear canal, but no mites. These findings suggested that as a potential insecticide, A. coerulea should be studied further to develop active components or a new acaricidal drug. PMID:23352106

Shang, Xiao-Fei; Miao, Xiao-Lou; Wang, Dong-Sheng; Li, Jian-Xi; Wang, Xue-Zhi; Yan, Zuo-Ting; Wang, Chun-Mei; Wang, Yu; He, Xi-Rui; Pan, Hu

2013-07-01

111

New nemadectin congeners with acaricidal and nematocidal activity from Streptomyces microflavus neau3 Y-3.  

PubMed

Two nemadectin congeners 1 and 2 were isolated from the fermentation broth of a mutant strain (Y-3) of Streptomyces microflavus neau3. Their structures were determined on the basis of extensive spectroscopic analysis and comparison with data from the literature. Compound 2 possessed a 5-membered ring lactone that is unprecedented among known milbemycins and avermectins. Both compounds 1 and 2 exhibited potent acaricidal activity and nematocidal activity. Especially, compound 2 demonstrated impressive acaricidal activity against adult mites with an IC50 of 2.3±0.9 ?g/mL and mite eggs with an IC50 of 17.5±2.1 ?g/mL and nematocidal activity against Caenorhabditis elegans with an IC50 of 0.7±0.2 ?g/mL, which are higher than those of nemadectin and the known commercial acaricide and nematocide milbemycin A3/A4. PMID:23992860

Yang, Ling-Yu; Wang, Ji-Dong; Zhang, Ji; Xue, Chang-Yan; Zhang, Hui; Wang, Xiang-Jing; Xiang, Wen-Sheng

2013-10-15

112

Acaricidal activity of five essential oils of Ocimum species on Rhipicephalus (Boophilus) microplus larvae.  

PubMed

The aim of this study was to evaluate the acaricidal activity on the cattle tick Rhipicephalus (Boophilus) microplus of essential oils from three Ocimum species. Acaricidal activity of five essential oils extracted from Ocimum gratissimum L. (three samples), O. urticaefolium Roth, and O. canum Sims was evaluated on 14- to 21-day-old Rhipicephalus microplus tick larvae using larval packet test bioassay. These essential oils were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS) showing great variations of their chemical compositions according to the botanical species and even within the O. gratissimum species; the acaricidal activity of their main compounds was also evaluated. The essential oils of O. urticaefolium and O. gratissimum collected in Cameroon were the most efficient with respective LC50 values of 0.90 and 0.98%. The two essential oils obtained from O. gratissimum collected in New Caledonia were partially active at a dilution of 5% while the essential oil of O. canum collected in Cameroon showed no acaricidal activity. The chemical analysis shows five different profiles. Whereas the essential oils of O. urticaefolium from Cameroon and O. gratissimum from New Caledonia contain high amounts of eugenol (33.0 and 22.3-61.0%, respectively), 1,8-cineole was the main component of the oil of an O. canum sample from Cameroon (70.2%); the samples of O. gratissimum oils from New Caledonia are also characterized by their high content of (Z)-?-ocimene (17.1-49.8%) while the essential oil of O. gratissimum collected in Cameroon is mainly constituted by two p-menthane derivatives: thymol (30.5%) and ?-terpinene (33.0%). Moreover, the essential oil of O. urticaefolium showed the presence of elemicin (18.1%) as original compound. The tests achieved with the main compounds confirmed the acaricidal activity of eugenol and thymol with residual activity until 0.50 and 1%, respectively, and revealed the acaricidal property of elemicin, which was the most efficient compound with 100 % of acaricidal activity at a dilution of 0.25% and could be a valuable acaricide for the control of the cattle tick R. microplus. PMID:25300420

Hüe, T; Cauquil, L; Fokou, J B Hzounda; Dongmo, P M Jazet; Bakarnga-Via, I; Menut, C

2015-01-01

113

Influence of long-term exposure to simulated acid rain on development, reproduction and acaricide susceptibility of the carmine spider mite, Tetranychus cinnabarinus  

PubMed Central

Development, reproduction and acaricide susceptibility of Tetranychus cinnabarinus (Boisduvals) (Acari: Tetranychidae) were investigated after long-term (about 40 generations) exposure to various levels of acid rain; pH 2.5, 3.0, 4.0, and 5.6. Deionized water (pH 6.8) served as a control. The mites were reared on eggplant leaves at 28°C, 80%RH and a photoperiod of 14:10 (L:D) in the laboratory. The results showed that the duration of the immature stage was significantly affected by acid rain exposure. The shortest duration (8.90 days) was recorded for populations exposed to pH 5.6 acid rain, while the longest duration (9.37 days) occurred after exposure to pH 2.5 acid rain. Compared with the control population, adult longevity was shortened with an increase in acidity. Similarly, the oviposition duration was also shortened by an increase in acidity. Statistically, female fecundity did not differ significantly between pH 5.6, pH 4.0 and control populations, but did differ significantly between the control population and those exposed to pH 2.5 and pH 3.0 acid rain. This suggested that the mite suffered reproductive defects after long-term exposure to acid rain with higher acidity (pH 2.5 and 3.0). The intrinsic rate of increase among different populations was not significantly affected, but the net reproductive rate of populations exposed to pH 2.5 and 3.0 acid rain was significantly less than pH4.0, 5.6, and control populations. Bioassay results showed that after long-term exposure to acid rain, susceptibility of the mites to two acaricides, dichlorvos and fenpropathrin, did not change significantly. PMID:19537978

Wang, Jin-Jun; Zhang, Jian-Ping; He, Lin; Zhao, Zhi-Mo

2006-01-01

114

[Treatment of scabies and Ascabiol(®) supply disruption: what about the pediatric population?].  

PubMed

Scabies is a disease in steady increase in Île-de-France region. Standard treatment, Ascabiol(®) (benzyl benzoate/sulfiram), is back-order for several months and its return remains uncertain. Facing this drug shortage, French Drug Agency (ANSM) has imported a drug from Germany, Antiscabiosum 10 % (benzyl benzoate), to treat patients having contraindications for other scabicides available in France (ivermectin, esdepallethrine). However, infants less than 1 year (<15 kg) and asthmatics infants have no alternative treatment. A multidisciplinary workgroup explored the various existing therapeutic alternatives in France and worldwide. From ANSM's recommendations and group's experience, a decision algorithm was proposed for treating patients. However, pediatric context implied the use of off-label drugs. Proposed treatments widely known by practitioners, prescriptions-types, dose, modalities of use and dispensation, and flyers to patients were realized to optimize treatment efficacy. PMID:24768069

Berthe-Aucejo, A; Prot-Labarthe, S; Pull, L; Lorrot, M; Touratier, S; Trout, H; Bourdon, O; Dehen, L; Bourrat, E

2014-06-01

115

ORGANIC BEEKEEPING AND ACARICIDE RESIDUES IN BEESWAX. RESEARCH IN THE LAZIO REGION (CENTRAL ITALY)  

Microsoft Academic Search

Summary The problem of acaricide residues in beeswax from organic beekeeping was investigated, through the analysis of different wax matrix: • some samples of certified organic wax resulted not completely free from residues; • cappings wax from conventional apiaries showed an average residue content of 0.7 mg\\/kg (maximum value 2.4); • brood combs from conventional apiaries treated with perizin and

Persano Oddo Livia; Pulcini Patrizio; Morgia Cinzia; Marinelli Enzo

116

Acaricide resistance of Rhipicephalus (Boophilus) microplus in State of Mato Grosso do Sul, Brazil  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study was performed to obtain an emerging view of the epidemiology of acaricide resistance in populations of R. microplus from Mato Grosso do Sul state in Brazil. Twenty four tick samples were collected from cities in the state where farmers reported concerns about resistance or failure of tick...

117

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 protein-coupled receptor / octopamine / thymol / tyramine 1. PLANT ESSENTIAL OILS-- AN INTRODUCTION

118

Effect of Various Acaricides on Hatchability of Eggs of Rhipicephalus (Boophilus) microplus  

PubMed Central

The effect of commonly used acaricides (amitraz, cypermethrin, deltamethrin, fenvalerate, and flumethrin) on the eggs of Rhipicephalus (Boophilus) microplus collected from Ludhiana, Punjab, was evaluated by egg hatch assay (EHA). The regression graph of probit hatchability and per cent inhibition of hatching (IH%) of eggs was plotted against log values of concentration of various acaricides. All concentrations of flumethrin and amitraz caused complete inhibition of hatching, whereas a hatchability of 31.0 ± 6.1, 40.0 ± 5.2 and 19.3 ± 1.7% was only recorded at the highest concentration of cypermethrin, deltamethrin, and fenvalerate, respectively. An increase in the concentration of the acaricide showed a significant effect on the IH% of eggs for cypermethrin (P < 0.01) and deltamethrin (P < 0.05) but was nonsignificant for fenvalerate. The slope of the regression curve of IH% was utilized for the calculation of the dose of various acaricides causing inhibition of hatching for 95% eggs (LC95) and the discriminating dose (DD). Results indicated that maximum DD was recorded for fenvalerate (2.136%), followed by cypermethrin (0.214%) and deltamethrin (0.118%). The results of the current study will be helpful in formulating effective control strategies against ticks. PMID:25057486

Haque, M.; Jyoti; Singh, N. K.; Rath, S. S.

2014-01-01

119

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

120

Scabies Treatment  

MedlinePLUS

... Chest & Lungs Chronic Conditions Developmental Disabilities Ear, Nose & Throat Emotional Problems Fever Genitals & Urinary Tract Head, Neck & Nervous System Obesity Skin Treatments View all Injuries & Emergencies Sports Injuries Vaccine Preventable Diseases Diphtheria Haemophilus ...

121

Relative resistance of the potato cultivar krantz to common scab caused by Streptomyces scabies as determined by cluster analysis  

Microsoft Academic Search

Twenty potato breeding selections and five potato cultivars (25 clones) were evaluated in replicated field plots for their\\u000a resistance to common scab caused byStreptomyces scabies, at Presque Isle, ME and Cranesville, WV in 1993. At harvest, all tubers in each plot were individually scored for the surface\\u000a area covered (0=0% to 5>75%) and for lesion type (0=no lesions to 5=pitted

Robert W. Goth; K. G. Haynes; R. J. Young; D. R. Wilson; F. I. Lauer

1995-01-01

122

Comparison of three methods for assessing varietal differences in resistance to common scab disease ( Streptomyces scabies ) of potato  

Microsoft Academic Search

Summary  Consistent varietal differences in scab severity were obtained when plants were grown in an open field or under a polythene\\u000a tunnel in soil naturally infested withStreptomyces scabies, or in a glasshouse in pots filled with artificially inoculated sand. It was concluded that the glasshouse pot-inoculation\\u000a technique would be the most suitable method to use in a breeding programme in which

R. E. Gunn; G. J. Jellis; P. J. Webb; N. C. Starling

1983-01-01

123

Disruption of sscR encoding a ?-butyrolactone autoregulator receptor in Streptomyces scabies NBRC 12914 affects production of secondary metabolites  

Microsoft Academic Search

We report the cloning and sequence analysis of a ?-butyrolactone autoregulator regulatory island that includes an sscR gene encoding the ?-butyrolactone autoregulator receptor from Streptomyces scabies NBRC 12914, a plant pathogenic strain. ?-Butyrolactone autoregulators trigger secondary metabolism, and sometimes morphological\\u000a differentiation in the Gram-positive genus Streptomyces through binding to a specific autoregulator receptor. This gene cluster showed close similarity to

S. Kitani; M. Hoshika; T. Nihira

2008-01-01

124

The ESX/type VII secretion system modulates development, but not virulence, of the plant pathogen Streptomyces scabies.  

PubMed

Streptomyces scabies is a model organism for the investigation of plant-microbe interactions in Gram-positive bacteria. Here, we investigate the type VII protein secretion system (T7SS) in S.?scabies; the T7SS is required for the virulence of other Gram-positive bacteria, including Mycobacterium tuberculosis and Staphylococcus aureus. The hallmarks of a functional T7SS are an EccC protein that forms an essential component of the secretion apparatus and two small, sequence-related substrate proteins, EsxA and EsxB. A putative transmembrane protein, EccD, may also be associated with T7S in Actinobacteria. In this study, we constructed strains of the plant pathogen S.?scabies carrying marked mutations in genes coding for EccC, EccD, EsxA and EsxB. Unexpectedly, we showed that all four mutant strains retain full virulence towards several plant hosts. However, disruption of the esxA or esxB, but not eccC or eccD, genes affects S.?scabies development, including a delay in sporulation, abnormal spore chains and resistance to lysis by the Streptomyces-specific phage ?C31. We further showed that these phenotypes are specific to the loss of the T7SS substrate proteins EsxA and EsxB, and are not observed when components of the T7SS secretion machinery are lacking. Taken together, these results imply an unexpected intracellular role for EsxA and EsxB. PMID:23009676

Fyans, Joanna K; Bignell, Dawn; Loria, Rosemary; Toth, Ian; Palmer, Tracy

2013-02-01

125

Long-term induction of defense gene expression in potato by pseudomonas sp. LBUM223 and streptomyces scabies.  

PubMed

Streptomyces scabies is a causal agent of common scab of potato, which generates necrotic tuber lesions. We have previously demonstrated that inoculation of potato plants with phenazine-1-carboxylic acid (PCA)- producing Pseudomonas sp. LBUM223 could significantly reduce common scab symptoms. In the present study, we investigated whether LBUM223 or an isogenic phzC- mutant not producing PCA could elicit an induced systemic resistance response in potato. The expression of eight defense-related genes (salicylic acid [SA]-related ChtA, PR-1b, PR-2, and PR-5; and jasmonic acid and ethylene-related LOX, PIN2, PAL-2, and ERF3) was quantified using newly developed TaqMan reverse-transcription quantitative polymerase chain reaction assays in 5- and 10-week-old potted potato plants. Although only wild-type LBUM223 was capable of significantly reducing common scab symptoms, the presence of both LBUM223 and its PCA-deficient mutant were equally able to upregulate the expression of LOX and PR-5. The presence of S. scabies overexpressed all SA-related genes. This indicates that (i) upregulation of potato defense-related genes by LBUM223 is unlikely to contribute to common scab's control and (ii) LBUM223's capacity to produce PCA is not involved in this upregulation. These results suggest that a direct interaction occurring between S. scabies and PCA-producing LBUM223 is more likely involved in controlling common scab development. PMID:24601985

Arseneault, Tanya; Pieterse, Corné M J; Gérin-Ouellet, Maxime; Goyer, Claudia; Filion, Martin

2014-09-01

126

Potential role of ATP-binding cassette transporters against acaricides in the brown dog tick Rhipicephalus sanguineus sensu lato.  

PubMed

ATP-binding cassette (ABC) transporters have been shown to be involved in pesticide detoxification in arthropod vectors and are thought to contribute to the development of drug resistance. Little is currently known about the role they play in ticks, which are among the more important vectors of human and animal pathogens. Here, the role of ABC transporters in the transport of fipronil and ivermectin acaricides in the tick Rhipicephalus sanguineus (Ixodida: Ixodidae) was investigated. Larvae were treated with acaricide alone and acaricide in combination with a sub-lethal dose of the ABC transporter inhibitor cyclosporine A. The LC50 doses and 95% confidence intervals (CIs) estimated by mortality data using probit analysis were 67.930?p.p.m. (95% CI 53.780-90.861) for fipronil and 3741?p.p.m. (95% CI 2857-4647) for ivermectin. The pre-exposure of larvae to a sub-lethal dose of cyclosporine A reduced the LC50 dose of fipronil to 4.808?p.p.m. (95% CI 0.715-9.527) and that of ivermectin to 167?p.p.m. (95% CI 15-449), which increased toxicity by about 14- and 22-fold, respectively. The comparison of mortality data for each separate acaricide concentration showed the synergic effect of cyclosporine A to be reduced at higher concentrations of acaricide. These results show for the first time a strong association between ABC transporters and acaricide detoxification in R.sanguineus s.l. PMID:25530472

Cafarchia, C; Porretta, D; Mastrantonio, V; Epis, S; Sassera, D; Iatta, R; Immediato, D; Ramos, R A N; Lia, R P; Dantas-Torres, F; Kramer, L; Urbanelli, S; Otranto, D

2015-03-01

127

The plant pathogen Streptomyces scabies 87-22 has a functional pyochelin biosynthetic pathway that is regulated by TetR- and AfsR-family proteins.  

PubMed

Siderophores are high-affinity iron-chelating compounds produced by bacteria for iron uptake that can act as important virulence determinants for both plant and animal pathogens. Genome sequencing of the plant pathogen Streptomyces scabies 87-22 revealed the presence of a putative pyochelin biosynthetic gene cluster (PBGC). Liquid chromatography (LC)-MS analyses of culture supernatants of S. scabies mutants, in which expression of the cluster is upregulated and which lack a key biosynthetic gene from the cluster, indicated that pyochelin is a product of the PBGC. LC-MS comparisons with authentic standards on a homochiral stationary phase confirmed that pyochelin and not enantio-pyochelin (ent-pyochelin) is produced by S. scabies. Transcription of the S. scabies PBGC occurs via ~19 kb and ~3 kb operons and transcription of the ~19 kb operon is regulated by TetR- and AfsR-family proteins encoded by the cluster. This is the first report, to our knowledge, of pyochelin production by a Gram-positive bacterium; interestingly regulation of pyochelin production is distinct from characterized PBGCs in Gram-negative bacteria. Though pyochelin-mediated iron acquisition by Pseudomonas aeruginosa is important for virulence, in planta bioassays failed to demonstrate that pyochelin production by S. scabies is required for development of disease symptoms on excised potato tuber tissue or radish seedlings. PMID:21757492

Seipke, Ryan F; Song, Lijiang; Bicz, Joanna; Laskaris, Paris; Yaxley, Alice M; Challis, Gregory L; Loria, Rosemary

2011-09-01

128

Insecticide/acaricide resistance in fleas and ticks infesting dogs and cats.  

PubMed

This review defines insecticide/acaricide resistance and describes the history, evolution, types, mechanisms, and detection of resistance as it applies to chemicals currently used against fleas and ticks of dogs and cats and summarizes resistance reported to date. We introduce the concept of refugia as it applies to flea and tick resistance and discuss strategies to minimize the impact and inevitable onset of resistance to newer classes of insecticides. Our purpose is to provide the veterinary practitioner with information needed to investigate suspected lack of efficacy, respond to lack of efficacy complaints from their clients, and evaluate the relative importance of resistance as they strive to relieve their patients and satisfy their clients when faced with flea and tick infestations that are difficult to resolve. We conclude that causality of suspected lack of insecticide/acaricide efficacy is most likely treatment deficiency, not resistance. PMID:24393426

Coles, Tad B; Dryden, Michael W

2014-01-01

129

Insecticide/acaricide resistance in fleas and ticks infesting dogs and cats  

PubMed Central

This review defines insecticide/acaricide resistance and describes the history, evolution, types, mechanisms, and detection of resistance as it applies to chemicals currently used against fleas and ticks of dogs and cats and summarizes resistance reported to date. We introduce the concept of refugia as it applies to flea and tick resistance and discuss strategies to minimize the impact and inevitable onset of resistance to newer classes of insecticides. Our purpose is to provide the veterinary practitioner with information needed to investigate suspected lack of efficacy, respond to lack of efficacy complaints from their clients, and evaluate the relative importance of resistance as they strive to relieve their patients and satisfy their clients when faced with flea and tick infestations that are difficult to resolve. We conclude that causality of suspected lack of insecticide/acaricide efficacy is most likely treatment deficiency, not resistance. PMID:24393426

2014-01-01

130

Determination of acaricides in honey by high-performance liquid chromatography with photodiode array detection.  

PubMed

Rapid analytical methods are described to control quality of honeys, concerning residues of acaricides applied in hives to prevent Varroa jacobsoni infestation. A liquid-liquid extraction with hexane-propanol-2-ammonia (60 ml:30 ml:0.28%) was used for the simultaneous analysis of coumaphos, bromopropylate, amitraz and fluvalinate. For thymol, one clean up on a solid-phase extraction C18 (500 mg, 6 ml) column was performed; for rotenone, a liquid extraction with dichloromethane was realised. Quantitative recoveries obtained with honey were satisfactory and were superior to 80%. All acaricides are identified by reversed-phase high-performance liquid chromatography with photodiode array detection. Quantification limits obtained were below maximal residue limits when these exist. PMID:12058901

Martel, Anne-Claire; Zeggane, Sarah

2002-04-19

131

Residual toxicity of some common acaricides in Brazil to the predacious mite Amblyseius brazilli  

Microsoft Academic Search

The direct toxicity of 5 common acaricides toAmblyseius brazilli\\u000a El-Banhawy was tested. Omethoate proved to be the most toxic and Chlorobenzilate the least toxic. LC50 were 1.2ppm, 220ppm, 720ppm and 1250ppm for Omethoate, Mexacarbate, Dicofol, Mitran and Chlorobenzilate respectively. The\\u000a indirect toxicity was also studied by providing the female predators with the phytophagous miteAponicus spinosus (Banks) previously treated by Chlorobenzilate

E. M. El-Banhawy

1976-01-01

132

Acaricide residues in laying hens naturally infested by red mite Dermanyssus gallinae.  

PubMed

In the poultry industry, control of the red mite D. gallinae primarily relies worldwide on acaricides registered for use in agriculture or for livestock, and those most widely used are carbamates, followed by amidines, pyrethroids and organophosphates. Due to the repeated use of acaricides--sometimes in high concentrations--to control infestation, red mites may become resistant, and acaricides may accumulate in chicken organs and tissues, and also in eggs. To highlight some situations of misuse/abuse of chemicals and of risk to human health, we investigated laying hens, destined to the slaughterhouse, for the presence of acaricide residues in their organs and tissues. We used 45 hens from which we collected a total of 225 samples from the following tissues and organs: skin, fat, liver, muscle, hearth, and kidney. In these samples we analyzed the residual contents of carbaryl and permethrin by LC-MS/MS.Ninety-one (40.4%) samples were positive to carbaryl and four samples (1.7%) were positive to permethrin. Concentrations of carbaryl exceeding the detection limit (0.005 ppm) were registered in the skin and fat of birds from two farms (p<0.01), although these concentrations remained below the maximum residue limit (MRLs) (0.05 ppm) (p<0.01). All organs/tissues of hens from a third farm were significantly more contaminated, with skin and muscle samples exceeding the MRL (0.05 ppm) (p<0.01) of carbaryl in force before its use was banned. Out of 45 chickens tested, 37 (82.2%) were found to be contaminated by carbaryl, and 4 (8.8%) by permethrin. The present study is the first report on the presence of pesticides banned by the EU (carbaryl) or not licensed for use (permethrin) in the organs and tissues of laying hens, which have been treated against red mites, and then slaughtered for human consumption at the end of their life cycle. PMID:22363736

Marangi, Marianna; Morelli, Vincenzo; Pati, Sandra; Camarda, Antonio; Cafiero, Maria Assunta; Giangaspero, Annunziata

2012-01-01

133

The toxicity of selected acaricides against five stored product mites under laboratory assay  

Microsoft Academic Search

In laboratory tests, the toxicity of acaricides targeted against house dust mites was tested on five species of stored product\\u000a mites (Acarus siro, Aleuroglyphus ovatus, Carpoglyphus lactis, Lepidoglyphus destructor, and Tyroborus lini). The formulations of benzyl-benzoate, benzyl-benzoate\\/permethrin\\/pyriproxyfen, and neem were diluted in water and applied\\u000a to filter paper in an unventilated chamber. The mortality of mites was observed after 24 h

Jitka Stará; Marta Nesvorna ´; Jan Hubert

134

Acaricide Residues in Laying Hens Naturally Infested by Red Mite Dermanyssus gallinae  

PubMed Central

In the poultry industry, control of the red mite D. gallinae primarily relies worldwide on acaricides registered for use in agriculture or for livestock, and those most widely used are carbamates, followed by amidines, pyrethroids and organophosphates. Due to the repeated use of acaricides - sometimes in high concentrations - to control infestation, red mites may become resistant, and acaricides may accumulate in chicken organs and tissues, and also in eggs. To highlight some situations of misuse/abuse of chemicals and of risk to human health, we investigated laying hens, destined to the slaughterhouse, for the presence of acaricide residues in their organs and tissues. We used 45 hens from which we collected a total of 225 samples from the following tissues and organs: skin, fat, liver, muscle, hearth, and kidney. In these samples we analyzed the residual contents of carbaryl and permethrin by LC-MS/MS. Ninety-one (40.4%) samples were positive to carbaryl and four samples (1.7%) were positive to permethrin. Concentrations of carbaryl exceeding the detection limit (0.005 ppm) were registered in the skin and fat of birds from two farms (p<0.01), although these concentrations remained below the maximum residue limit (MRLs) (0.05 ppm) (p<0.01). All organs/tissues of hens from a third farm were significantly more contaminated, with skin and muscle samples exceeding the MRL (0.05 ppm) (p<0.01) of carbaryl in force before its use was banned. Out of 45 chickens tested, 37 (82.2%) were found to be contaminated by carbaryl, and 4 (8.8%) by permethrin. The present study is the first report on the presence of pesticides banned by the EU (carbaryl) or not licensed for use (permethrin) in the organs and tissues of laying hens, which have been treated against red mites, and then slaughtered for human consumption at the end of their life cycle. PMID:22363736

Marangi, Marianna; Morelli, Vincenzo; Pati, Sandra; Camarda, Antonio; Cafiero, Maria Assunta; Giangaspero, Annunziata

2012-01-01

135

Repellents and acaricides as personal protection measures in the prevention of tick-borne diseases.  

PubMed

A number of preventive measures for the protection of humans against tick-borne diseases were evaluated. Measures involving the avoidance of tick bites with the use of protective clothing and insect repellents are the simplest and most effective. Repellents are applied directly to the skin or clothing and other fabrics, such as bednets, tents and anti-mosquito screens. Currently, DEET (N,N-diethyl-m-toluamide) is considered the most efficient arthropod repellent reference substance. The registered and recommended active repellent ingredients for skin and/or cloths application, among others, are: DEET, 1-methyl-propyl-2- (hydroxyethyl)-1-piperidinecarboxylate (picaridin), p-menthane-3,8-diol (PMD), ethyl butylactyloaminopropionate ( IR3535), 1S,2S-2-methylpiperidinyl-3-cyclohexene-1-carboxamide (SS220), racemic 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (AI3-37220) and synthethic pyrethroid - 3-phenoxybenzyl-cis-trans-3(2,2 dichlorovinyl)-2,2-dimethylcyclopropancarboxylate (permethrin) - an acaricide with repellent properties. To achieve the protection from tick bites by avoiding attachment and/or engorgement by the arthropod, acaricides with repellent properties, such as synthetic pyrethroid-permethrin are used. This pyrethroid is an acaricide of choice used for clothing impregnation, which is effective for personal protection against all three parasitic stages of western black-legged ticks. Products based on natural compounds, e.g. eugenol from Ocimum basilicum, 2-undecanone originally derived from wild tomato, geraniol - a natural product extracted from plants, and many others, represent an interesting alternative to common synthetic repellents and/or acaricides. PMID:23311778

Cisak, Ewa; Wójcik-Fatla, Angelina; Zaj?c, Violetta; Dutkiewicz, Jacek

2012-01-01

136

Effects of an acaricide on mite allergen levels in the homes of asthmatic children.  

PubMed

Previous study by the current authors has shown that treating homes with D'Allergen, an acaricidal agent, can reduce bronchial hyper-reactivity in asthmatic children with house dust mite allergy. In the present study, the effects of a single D'Allergen treatment on the levels of major dust mite allergens, Der p I and Der f I was evaluated, and the duration of its effectiveness in the environment determined. Twenty randomly selected homes were treated with the acaricide and ten remained untreated. Dust samples were collected from mattresses, upholstered sofas and carpets of these homes before and 1, 2 and 4 months after treatment. The samples were then assayed for Der p I and Der f I allergens using a sandwich enzyme immunoassay. The results showed that D'Allergen was effective in reducing dust mite allergen levels in all three niches by 1.5-22.3 times below baseline values. This effect, however, was only present for 2 months, and the dust mite allergen levels increased to those of the baseline by the fourth month after treatment. These results indicated that repeated applications of the acaricide were required at 2-3 monthly intervals to obtain optimal effectiveness. PMID:8942008

Chew, F T; Goh, D Y; Lee, B W

1996-10-01

137

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

138

Comparing the efficacy of oral ivermectin vs malathion 0.5% lotion for the treatment of scabies.  

PubMed

Scabies is found worldwide among people of all groups and ages. It is curable with scabicide medications. This study aimed to compare the efficacy and safety of oral ivermectin vs malathion 0.5% lotion for the treatment of scabies. In total, 148 patients with scabies were enrolled and randomized into two groups: the first group received a single dose of oral ivermectin 200 sg/kg body weight, and the second was treated with two applications of topical lindane lotion 1%, with a 1-week interval between applications. Treatment was evaluated at intervals of 2 and 4 weeks, and if there was treatment failure at the 2-week follow-up, treatment was repeated. A single dose of ivermectin provided a cure rate of 60.8% at the 2-week follow-up, which increased to 89.1% at the 4-week follow-up after repeating the treatment. Treatment with two applications oflindane lotion 1%, with a 1-week interval between them, was effective in 47.2% of patients at the 2-week follow-up, which increased to 72.9% at the 4-week follow-up after this treatment was repeated. A single dose of ivermectin was as effective as two applications of lindane lotion 1% at the 2-week follow-up. After repeat treatment, ivermectin was superior to lindane lotion 1% at the 4-week follow-up. The delay in clinical response with ivermectin suggests that it may not be effective against the parasite at all stages in the life cycle. PMID:25632646

Goldust, Mohamad; Rezaee, Elham; Raghifar, Ramin; Hemayat, Sevil

2014-01-01

139

Isolation and characterization of two types of actinophages infecting Streptomyces scabies MR13.  

PubMed

Two types of actinophages, phi S and phi L, were isolated from soil samples by using Streptomyces scabies MR13, a potato scab pathogen, as an indicator strain. The phages were partially characterized according to their physicochemical properties, plaques and particles morphology and their host-range. The host-range of these phages was narrow for phi S and wide for phi L. The adsorption rate constants of the phi S and phi L were 3.44 x 10(-9) and 3.18 x 10(-9) ml/min, and their burst sizes were 1.61 and 3.75 virions, respectively. One-step growth indicated that phi S and phi L have a latent period of 30 min followed by a rise period of 30 min. The temperate character of these phages was tested in other isolates of Streptomyces. Four of the phages (phi SS3, phi SS12, phi SS13 and phi SS17) were identified as temperate phages, since they were able to lysogenize SS3, SS12, SS13 and SS17. phi SS3, phi SS12 and phi SS13 were homoimmune, and they were heteroimmune with respect to phi SS17. The restriction barriers of lysogenic isolates (SS12, SS13 and SS17) interfered with the blockage of plaques formation by phages (phi SS12, phi SS13 or phi SS17) propagated on them, about 75% of lysogenic isolates had restriction systems. The exposure of the lysogenic isolates (SS12, SS13 and SS17) to UV-irradiation prevented the possible restriction barriers of these isolates, and these barriers could be overcome. PMID:12512256

el-Sayed, A el-S; el-Didamony, G; Mansour, K

2002-01-01

140

Isolation and characterization of two types of actinophage infecting Streptomyces scabies.  

PubMed

Two types of actinophages, phi S and phi L, were isolated from soil samples by using Streptomyces scabies, a potato scab pathogen, as indicator strain. The phages were partially characterized according to their physicochemical properties, plaques and particles morphology, and their host range; this varied from narrow (for phi S) to wide (for phi L). The adsorption rate constants of the phi S and phi L were 3.44 and 3.18 pL/min, and their burst sizes were 1.61 and 3.75 virions per mL, respectively. One-step growth indicated that phi S and phi L have a latent period of 1/2 h followed by a rise period of 1/2 h. The temperate character of these phages was tested in other isolates of Streptomyces. Four of the phages (phi SS3, phi SS12, phi SS13 and phi SS17) were identified as temperate phages, since they were able to lysogenize SS3, SS12, SS13 and SS17. phi SS3, phi SS12 and phi SS13 were homoimmune, and they were heteroimmune with respect to phi SS17. The restriction barriers of lysogenic isolates (SS12, SS13 and SS17) interfered with the blockage of plaque formation by phages (phi SS12, phi SS13 or phi SS17) propagated on them, about 75% of lysogenic isolates had restriction systems. The exposure of the lysogenic isolates (SS12, SS13 and SS17) to UV-irradiation prevented the possible restriction barriers of these isolates so that these barriers could be overcome. PMID:11898342

el-Sayed, el-S A; el-Didamony, G; Mansour, K

2001-01-01

141

RHIZOCTONIA SOLANI AND STREPTOMYCES SCABIES ON SPROUTS AND TUBERS OF POTATO GROWN IN ORGANIC AND INTEGRATED SYSTEMS, AND FUNGAL COMMUNITIES IN THE SOIL HABITAT  

Microsoft Academic Search

The health of sprouts and tubers of six potato cultivars was compared in or- ganic and integrated systems of cultivation in field experiments in 2002-2004. The study included analysis of the structure of fungal communities from both systems. There was much disease in all years. The incidence of sprout rot (Rhizoctonia solani) and common scab (Streptomyces scabies) was less in

L. Lenc

142

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

143

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

144

Regulation of Coronafacoyl Phytotoxin Production by the PAS-LuxR Family Regulator CfaR in the Common Scab Pathogen Streptomyces scabies  

PubMed Central

Potato common scab is an economically important crop disease that is characterized by the formation of superficial, raised or pitted lesions on the potato tuber surface. The most widely distributed causative agent of the disease is Streptomyces scabies, which produces the phytotoxic secondary metabolite thaxtomin A that serves as a key virulence factor for the organism. Recently, it was demonstrated that S. scabies can also produce the phytotoxic secondary metabolite coronafacoyl-L-isoleucine (CFA-L-Ile) as well as other related metabolites in minor amounts. The expression of the biosynthetic genes for CFA-L-Ile production is dependent on a PAS-LuxR family transcriptional regulator, CfaR, which is encoded within the phytotoxin biosynthetic gene cluster in S. scabies. In this study, we show that CfaR activates coronafacoyl phytotoxin production by binding to a single site located immediately upstream of the putative -35 hexanucleotide box within the promoter region for the biosynthetic genes. The binding activity of CfaR was shown to require both the LuxR and PAS domains, the latter of which is involved in protein homodimer formation. We also show that CFA-L-Ile production is greatly enhanced in S. scabies by overexpression of both cfaR and a downstream co-transcribed gene, orf1. Our results provide important insight into the regulation of coronafacoyl phytotoxin production, which is thought to contribute to the virulence phenotype of S. scabies. Furthermore, we provide evidence that CfaR is a novel member of the PAS-LuxR family of regulators, members of which are widely distributed among actinomycete bacteria. PMID:25826255

Cheng, Zhenlong; Bown, Luke; Tahlan, Kapil; Bignell, Dawn R. D.

2015-01-01

145

Regulation of Coronafacoyl Phytotoxin Production by the PAS-LuxR Family Regulator CfaR in the Common Scab Pathogen Streptomyces scabies.  

PubMed

Potato common scab is an economically important crop disease that is characterized by the formation of superficial, raised or pitted lesions on the potato tuber surface. The most widely distributed causative agent of the disease is Streptomyces scabies, which produces the phytotoxic secondary metabolite thaxtomin A that serves as a key virulence factor for the organism. Recently, it was demonstrated that S. scabies can also produce the phytotoxic secondary metabolite coronafacoyl-L-isoleucine (CFA-L-Ile) as well as other related metabolites in minor amounts. The expression of the biosynthetic genes for CFA-L-Ile production is dependent on a PAS-LuxR family transcriptional regulator, CfaR, which is encoded within the phytotoxin biosynthetic gene cluster in S. scabies. In this study, we show that CfaR activates coronafacoyl phytotoxin production by binding to a single site located immediately upstream of the putative -35 hexanucleotide box within the promoter region for the biosynthetic genes. The binding activity of CfaR was shown to require both the LuxR and PAS domains, the latter of which is involved in protein homodimer formation. We also show that CFA-L-Ile production is greatly enhanced in S. scabies by overexpression of both cfaR and a downstream co-transcribed gene, orf1. Our results provide important insight into the regulation of coronafacoyl phytotoxin production, which is thought to contribute to the virulence phenotype of S. scabies. Furthermore, we provide evidence that CfaR is a novel member of the PAS-LuxR family of regulators, members of which are widely distributed among actinomycete bacteria. PMID:25826255

Cheng, Zhenlong; Bown, Luke; Tahlan, Kapil; Bignell, Dawn R D

2015-01-01

146

Acaricidal activity of aqueous extract and synthesized silver nanoparticles from Manilkara zapota against Rhipicephalus (Boophilus) microplus.  

PubMed

Traditional parasite control is primarily based on the use of chemical acaricides, which unfortunately have many negative side effects. The aim of the present study was to evaluate the effect of plant synthesized silver nanoparticles (AgNPs) using aqueous leaf extract of Manilkara zapota to control Rhipicephalus (Boophilus) microplus. The synthesized AgNPs were characterized by UV-vis spectrum, scanning electron microscopy (SEM), Fourier transform infrared and X-ray diffraction. The UV-vis spectrum of the aqueous medium containing silver nanostructures showed a peak at 421 nm corresponding to the surface plasmon resonance band of AgNPs. SEM supports the biosynthesis and characterization of AgNPs with spherical and oval in shape and size of 70-140 nm. Acaricidal activity of aqueous leaf extract of M. zapota and synthesized AgNPs were carried out against R. (B.) microplus and the results showed the LC(50) values of 16.72 and 3.44 mg/L; r(2)=0.856 and 0.783), respectively. PMID:21906765

Rajakumar, G; Abdul Rahuman, A

2012-08-01

147

Rhipicephalus (Boophilus) microplus resistant to acaricides and ivermectin in cattle farms of Mexico.  

PubMed

Ticks and the diseases they transmit cause great economic losses to livestock in tropical countries. Non-chemical control alternatives include the use of resistant cattle breeds, biological control and vaccines. However, the most widely used method is the application of different chemical classes of acaricides and macrocyclic lactones. Populations of the cattle tick, Rhipicephalus (Boophilus) microplus, resistant to organophosphates (OP), synthetic pyrethroids (SP), amitraz and fipronil have been reported in Mexico. Macrocyclic lactones are the most sold antiparasitic drug in the Mexican veterinary market. Ivermectin-resistant populations of R. (B.) microplus have been reported in Brazil, Uruguay and especially in Mexico (Veracruz and Yucatan). Although ivermectin resistance levels in R. (B.) microplus from Mexico were generally low in most cases, some field populations of R. (B.) microplus exhibited high levels of ivermectin resistance. The CHPAT population showed a resistance ratio of 10.23 and 79.6 at lethal concentration of 50% and 99%, respectively. Many field populations of R. (B.) microplus are resistant to multiple classes of antiparasitic drugs, including organophosphates (chlorpyrifos, coumaphos and diazinon), pyrethroids (flumethrin, deltamethrin and cypermethrin), amitraz and ivermectin. This paper reports the current status of the resistance of R. (B.) microplus to acaricides, especially ivermectin, in Mexican cattle. PMID:25054487

Rodríguez-Vivas, Róger Iván; Pérez-Cogollo, Luis Carlos; Rosado-Aguilar, José Alberto; Ojeda-Chi, Melina Maribel; Trinidad-Martinez, Iris; Miller, Robert John; Li, Andrew Yongsheng; de León, Adalberto Pérez; Guerrero, Félix; Klafke, Guilherme

2014-01-01

148

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

149

Beauveria bassiana: Synergistic effect with acaricides against the tick Hyalomma anatolicum anatolicum (Acari: Ixodidae).  

PubMed

Owing to the need to combat the spread of chemical acaricide resistance in ticks, we evaluated the efficacy of a mixture of the entomopathogenic fungus Beauveria bassiana AT17 and acaricides for the control of Hyalomma anatolicum anatolicum in China. A mixture of B. bassiana AT17 at the concentration of 10(8)conidia/mL and the synthetic pyrethroid deltamethrin at concentrations of 2500, 250, 25, 5, 2.5, 0.5 and 0.25ppm was tested in vitro. The germination capability, vegetative growth, conidia production, and viability of B. bassiana AT17 were assessed and the efficacy of the mixture in killing engorged H. anatolicum anatolicum females was measured. High mortality rates were achieved when the entomopathogen was combined with different concentrations of deltamethrin. Neither B. bassiana AT17 nor deltamethrin alone at the same concentrations could cause the higher mortality rates seen with the combination. In addition the combination killed the ticks more rapidly than did either agent alone (3-5days more rapidly). Our results indicate that the mixture of B. bassiana AT17 and deltamethrin has potential as a new type of reagent for integrated control of H. anatolicum anatolicum. PMID:21440547

Sun, Ming; Ren, Qiaoyun; Liu, Zhijie; Guan, Guiquan; Gou, Huitian; Ma, Miling; Li, Youquan; Liu, Aihong; Yang, Jifei; Yin, Hong; Luo, Jianxun

2011-07-01

150

Acaricidal activity of extracts from Petiveria alliacea (Phytolaccaceae) against the cattle tick, Rhipicephalus (Boophilus) microplus (Acari: ixodidae).  

PubMed

The acaricidal activity of crude extracts and fractions from stems and leaves of Petiveria alliacea (Phytolaccaceae) was carried out on larvae and adults of the cattle tick Rhipicephalus (Boophilus) microplus using the larval immersion test (LIT) and adult immersion test (AIT), respectively. Methanolic extracts of stems and leaves of P. alliacea showed 100% mortality on the LIT bioassay. On the other hand, methanolic extracts of leaves and stem on the AIT test showed 26% and 86% of mortality, respectively, egg laying inhibition of 40% and 91%, respectively and hatchability inhibition of 26% and 17%, respectively. Purification of the active stem methanolic extract showed that the activity was present in the n-hexane non-polar fraction. Bioassay-guided purification of the n-hexane fraction produced 10 semi-purified fractions; fraction B had the highest activity against tick larvae (100% mortality). Gas chromatography-mass spectrometry demonstrated that the chemical composition of the active fraction B samples were mainly composed of benzyltrisulfide (BTS) and benzyldisulfide (BDS). These metabolites might be responsible for the acaricidal activity of stem extract of P. alliacea. However, further experiments to evaluate the acaricidal activity of BTS and BDS on larvae and adults of R. (B.) microplus are needed. Our results showed that P. alliacea is a promising biocontrol candidate as acaricide against R. (B.) microplus resistant strains. PMID:20042296

Rosado-Aguilar, J A; Aguilar-Caballero, A; Rodriguez-Vivas, R I; Borges-Argaez, R; Garcia-Vazquez, Z; Mendez-Gonzalez, M

2010-03-25

151

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

152

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

153

First report of fluazuron resistance in Rhipicephalus microplus: a field tick population resistant to six classes of acaricides.  

PubMed

The control of the cattle tick Rhipicephalus microplus is based mainly on the use of chemical acaricides, which has contributed to the emerging problem of selection of resistant tick populations. Currently, there are six main classes of acaricides commercially available in Brazil to control cattle ticks, with fluazuron, a tick growth regulator with acaricidal properties, being the only active ingredient with no previous reports of resistance. Ticks (designated the Jaguar strain) were collected in a beef cattle ranch located at Rio Grande do Sul state, Southern Brazil, after a complaint of fluazuron treatment failure. To characterise the resistance of this strain against acaricides, larval tests were performed and showed that the Jaguar strain was resistant to all of the drugs tested: cypermethrin (resistance ratio, RR=31.242), chlorpyriphos (RR=103.926), fipronil (RR=4.441), amitraz (RR=11.907) and ivermectin (3.081). A field trial was conducted to evaluate the efficacy of fluazuron treatment in heifers that had been experimentally infested with the Jaguar or a susceptible strain. Between 14 and 28 days after treatment, the average efficacy in cattle experimentally infested with the susceptible strain was 96%, while for the Jaguar strain the efficacy was zero. Additionally, the Jaguar strain response to fluazuron was evaluated in vitro using a modified adult immersion test (AIT) and the artificial feeding assay (AFA). With the AIT, 50 ppm of fluazuron inhibited 99% of larvae hatching in the susceptible strain (POA) and less than 50% in the Jaguar strain. Results of the AFA showed a larval hatching rate of 67% at 2.5 ppm of fluazuron with the Jaguar strain; conversely, only 3% of larvae of the susceptible strain hatched at the same fluazuron concentration. The results showed here demonstrated the first case of fluazuron resistance in R. microplus and the first tick population resistant to six classes of acaricides in Brazil. PMID:24560364

Reck, José; Klafke, Guilherme Marcondes; Webster, Anelise; Dall'Agnol, Bruno; Scheffer, Ramon; Souza, Ugo Araújo; Corassini, Vivian Bamberg; Vargas, Rafael; dos Santos, Julsan Silveira; Martins, João Ricardo de Souza

2014-03-17

154

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

155

Evaluation of the Efficacy of Acaricides Used to Control the Cattle Tick, Rhipicephalus microplus, in Dairy Herds Raised in the Brazilian Southwestern Amazon  

PubMed Central

The adult immersion test (AIT) was used to evaluate the efficacy of acaricide molecules used for control of Rhipicephalus microplus on 106 populations collected in five municipalities in the state of Rondônia in the Brazilian South Occidental Amazon region. The analysis of the data showed that the acaricide formulations had different efficacies on the tick populations surveyed. The synthetic pyrethroids (SPs) acaricides were the least effective (48.35–76.84%), followed by SP + organophosphate (OP) associations (68.91–81.47%) and amidine (51.35–100%). For the macrocyclic lactones (MLs), the milbemycin (94.84–100%) was the most effective, followed by spinosad (93.21–100%) and the avermectins (81.34–100%). The phenylpyrazole (PZ) group had similar efficacy (99.90%) to the MLs. Therefore, SP acaricides, including associations with OP, and formulations based on amidine presented low in vitro efficacy to control the R. microplus populations surveyed. PMID:21547224

Brito, Luciana G.; Barbieri, Fábio S.; Rocha, Rodrigo B.; Oliveira, Márcia C. S.; Ribeiro, Elisana Sales

2011-01-01

156

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

157

The development of resistance to organophosphorus compounds by Tetranychus (T.) urticae Koch and laboratory and field toxicological responses of Tetranychus (T.) Cinnabarinus (Boisduval) to some current acaricides  

E-print Network

THE DEVELOPMENT OF RESISTANCE TO ORGANOPHOSPHORUS CONPOUNDS BY TETRANYCHUS (T ) URTICAE KOCH AND 1 ABORATORY AND FIELD TOXICOLOGICAL RESPONSES OF TETRANYCHUS (T ) CINNABARINUS ( BOISDUVAL) TO SOKE CURRENT ACARICIDES A Thesis by SAUL E... TO ORGANOPHOSPHORUS COMPOUNDS BY TETRANYCHUS (T ) URTICAE KOCH AND LABORATORY AND FIELD TOXICOLOGICAL RESPONSES OF TETRANYCHUS (T ~ ) CINNABARINUS ( BOISDUVAL) TO SOME CURRENT ACARICIDES PC A R o o III Pc R O A Thesis by SAUL ED CONTRERAS G Approved...

Contreras Galvez, Saul Edgardo

1971-01-01

158

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

159

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

160

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

161

Effects of acaricides, pyrethroids and predator distributions on populations of Tetranychus urticae in apple orchards.  

PubMed

We sampled mites in three apple orchards in Nova Scotia, Canada, that had been inoculated with pyrethroid-resistant Typhlodromus pyri and had a history of Tetranychus urticae outbreaks. The objective of this study was to monitor populations of T. urticae and phytoseiid predators on the ground and in trees and to track dispersal between the two habitats. Pesticides were the chief cause of differences in mite dynamics between orchards. In two orchards, application of favourably selective acaricides (abamectin, clofentezine) in 2002, coupled with predation by T. pyri in trees and Neoseiulus fallacis in ground cover, decreased high T. urticae counts and suppressed Panonychus ulmi. By 2003 phytoseiids kept the tetranychids at low levels. In a third orchard, application of pyrethroids (cypermethrin, lambda-cyhalothrin), plus an unfavourably selective acaricide (pyridaben) in 2003, suppressed phytoseiids, allowing exponential increases of T. urticae in the ground cover and in tree canopies. By 2004 however, increasing numbers of T. pyri and application of clofentezine strongly reduced densities of T. urticae in tree canopies despite high numbers crawling up from the ground cover. Another influence on T. urticae dynamics was the distribution of the phytoseiids, T. pyri and N. fallacis. When harsh pesticides were avoided, T. pyri were numerous in tree canopies. Conversely, only a few N. fallacis were found there, even when they were present in the ground cover and on tree trunks. Low numbers were sometimes due to pyrethroid applications or to scarcity of prey. Another factor was likely the abundance of T. pyri, which not only competes with N. fallacis, but also feeds on its larvae and nymphs. The scarcity of a specialist predator of spider mites in trees means that control of T. urticae largely depends on T. pyri, a generalist predator that is not particularly effective in regulating T. urticae. PMID:18008172

Hardman, J M; Franklin, J L; Beaulieu, F; Bostanian, N J

2007-01-01

162

Eine Methode zur Prüfung von Wild und Primitivkartoffeln auf ihr Verhalten gegenüber dem Kartoffelschorf, Streptomyces scabies (Thaxter)Waksman etHenrici  

Microsoft Academic Search

1.Eine Methode zur Prüfung wilder und primitiver Kartoffelformen auf Resistenz gegen Kartoffelschorf (Streptomyces scabies) wird beschrieben.2.Die Methode basiert auf der hydroponischen Kultur von Kartoffelpflanzen in Glaszylindern unter Kurztagsbedingungen. Dadurch wird eine schnelle Knollenentwicklung hervorgerufen. Die gebildeten Knollen werden in einem frühen Entwicklungsstadium mit einer Schorfsporensuspension infiziert.3.6–8 Wochen nach Untersuchungsbeginn kann bereits das Verhalten der Kartoffelformen gegenüber Schorf bonitiert werden.4.Bis jetzt

D. Rothacker; M. Haussdörfer

1958-01-01

163

Involvement of the plant polymer Suberin and the disaccharide cellobiose in triggering thaxtomin A biosynthesis, a phytotoxin produced by the pathogenic agent streptomyces scabies.  

PubMed

Streptomyces scabies is a gram-positive soil bacterium recognized as the main causal agent of common scab. Pathogenicity in Streptomyces spp. depends on their capacity to synthesize phytotoxins called thaxtomins. Genes involved in biosynthesis of these secondary metabolites are known to be induced by cellobiose, a plant disaccharide. However, growth of S. scabies in a minimal medium containing cellobiose as a carbon source is very poor and only generates traces of thaxtomins. The effect of suberin, a lipid plant polymer, on thaxtomin A biosynthesis and the expression of genes involved in its biosynthetic pathway was analyzed. S. scabies was grown in a starch-containing minimal medium supplemented with cellobiose (0.5%), suberin (0.1%), or both. The presence of both cellobiose and suberin doubled bacterial growth and triggered thaxtomin A production, which correlated with the upregulation (up to 342-fold) of genes involved in thaxtomins synthesis. The addition of either suberin or cellobiose alone did not affect these parameters. Suberin appeared to stimulate the onset of secondary metabolism, which is a prerequisite to the production of molecules such as thaxtomin A, while cellobiose induced the biosynthesis of this secondary metabolite. PMID:19968554

Lerat, Sylvain; Simao-Beaunoir, Anne-Marie; Wu, Run; Beaudoin, Nathalie; Beaulieu, Carole

2010-01-01

164

Structure and biosynthesis of scabichelin, a novel tris-hydroxamate siderophore produced by the plant pathogen Streptomyces scabies 87.22.  

PubMed

Scabichelin and turgichelin, novel tris-hydroxamate siderophores, were isolated from Streptomyces antibioticus NBRC 13838/Streptomyces scabies JCM 7914 and Streptomyces turgidiscabies JCM 10429, respectively. The planar structures of scabichelin and turgichelin were elucidated by mass spectrometry, and 1- and 2-D NMR spectroscopic analyses of their gallium(III) complexes. The relative and absolute stereochemistry of the metabolites was determined by the modified Marfey's method in conjunction with computational modelling and NOESY NMR analysis of Ga-scabichelin and Ga-turgichelin. Genome sequence analysis of the plant pathogen Streptomyces scabies 87.22 identified a gene cluster containing a gene encoding a nonribosomal peptide synthetase (NRPS) that was predicted to direct the production of a pentapeptide with structural similarities to scabichelin and turgichelin. Comparative LC-MS/MS analyses of iron-deficient culture supernatants from wild type S. scabies 87.22 and a mutant in which the NRPS gene had been disrupted, and scabichelin purified from S. antibioticus, showed that scabichelin is the metabolic product of the cryptic gene cluster, strongly suggesting that it functions as a siderophore. PMID:23752895

Kodani, Shinya; Bicz, Joanna; Song, Lijiang; Deeth, Robert J; Ohnishi-Kameyama, Mayumi; Yoshida, Mitsuru; Ochi, Kozo; Challis, Gregory L

2013-07-28

165

Susceptibility of two bulb mites, Rhizoglyphus robini and R. setosus (Acarina: Acaridae), to some acaricides and insecticides  

Microsoft Academic Search

The susceptibility of two field-collected bulb mites,Rhizoglyphus robini andR. setosus to some organophosphorus, carbamates, pyrethroids and other compounds with acaricidal activity was evaluated. In general,R. setosus was more tolerant to these compounds thanR. robini. Among the 58 commercially formulated compounds tested,R. robini was susceptible to chlorpyrifos 22.5% EC, EPN 45% EC, ethion 46.5% EC, fenitrothion 50% EC, methamidophos 50% S,

JENG-SHONG CHEN; Kang-Chenlo

1989-01-01

166

Acaricidal activity of the essential oil from Tetradenia riparia (Lamiaceae) on the cattle tick Rhipicephalus ( Boophilus) microplus (Acari; Ixodidae)  

Microsoft Academic Search

Tetradenia riparia (Lamiaceae) is a well-known herbal medicine with a variety of useful properties, including its acaricidal effect. This experiment was carried out to study the bioacaricidal activity of T. riparia essential oil (EO) against engorged females of Rhipicephalus (Boophilus) microplus (Acari; Ixodidae). For this purpose, nine serial concentrations (12.50%, 6.25%, 3.75%, 1.80%, 0.90%, 0.45%, 0.22%, 0.11%, and 0.056% w\\/v)

Zilda Cristiani Gazim; Izabel Galhardo Demarchi; Maria Valdrinez Campana Lonardoni; Ana Carolina L. Amorim; Ana Maria C. Hovell; Claudia Moraes Rezende; Gilberto Alves Ferreira; Edson Luiz de Lima; Fábio Antunes de Cosmo; Diogenes Aparício Garcia Cortez

2011-01-01

167

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

168

Studies on the acaricidal mechanism of the active components from neem (Azadirachta indica) oil against Sarcoptes scabiei var. cuniculi.  

PubMed

Octadecanoic acid-3,4-tetrahydrofuran diester, isolated from neem (Azadirachta indica) oil, exhibited potent acaricidal activity against Sarcoptes scabiei var. cuniculi. In this paper, the acaricidal mechanism of octadecanoic acid-3,4-tetrahydrofuran diester against Sarcoptes scabiei var. cuniculi was evaluated based on pathologic histology and enzyme activities. The results showed that after compound treatment for 24h at a concentration of 20mg/mL, the lesions of mites were prominent under transmission electron microscopy. The lesions consisted of the lysis of dermis cell membranes and cell nuclear membranes, mitochondrial morphological abnormalities, the drop of spinal disorders, and mitochondrial vacuolization. The activity of superoxide dismutase (SOD), peroxidase (POD), glutathione-s-transferases (GSTs), and Ca(2+)-ATPase of mites significantly changed after treatment with octadecanoic acid-3,4-tetrahydrofuran diester compared with the control group. The activities of SOD, POD, and Ca(2+)-ATPase were significantly suppressed, whereas that of GSTs was activated. These results indicated that the mechanism of the acaricidal activity of octadecanoic acid-3,4-tetrahydrofuran diester was mainly achieved through interference with the energy metabolism of mites, thus resulting in insect death. PMID:24974121

Chen, Zhen-zhen; Deng, Yun-xia; Yin, Zhong-qiong; Wei, Qin; Li, Mei; Jia, Ren-yong; Xu, Jiao; Li, Li; Song, Xu; Liang, Xiao-xia; Shu, Gang; He, Chang-liang; Gu, Xiao-bin; Lv, Cheng; Yin, Lizi

2014-08-29

169

Toxicity of acaricides to Raoiella indica and their selectivity for its predator, Amblyseius largoensis (Acari: Tenuipalpidae: Phytoseiidae).  

PubMed

Raoiella indica Hirst (Acari: Tenuipalpidae) is considered a pest of coconut palm in Asia and the Middle East. This mite was recently introduced in the Americas, where it spread to several countries and expanded its range of hosts, causing heavy losses to coconut and banana production. The phytoseiid mite Amblyseius largoensis (Muma) is one of the predators most often encountered in coconut palms. Because the current prospects for the control of R. indica in the New World indicate the use of acaricides and the management of their natural enemies, the objective of this study was to evaluate the toxicity of selected acaricides to R. indica and the selectivity (i.e., toxicity to the predator relative to toxicity to the prey) for A. largoensis. Assays were performed by the immersion of banana leaf discs in acaricide solutions, followed by the placing of adult females of the pest or predator on the discs. Mortality of the mites was evaluated after 24 h, and the data obtained were subjected to probit analysis. Abamectin, fenpyroximate, milbemectin and spirodiclofen were the products most toxic to R. indica adults, whereas fenpyroximate and spirodiclofen were the most selective for A. largoensis. PMID:23229493

de Assis, Carla P O; de Morais, Elisângela G F; Gondim, Manoel G C

2013-07-01

170

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. PMID:25436226

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

171

Identification of potential plant extracts for anti-tick activity against acaricide resistant cattle ticks, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).  

PubMed

To develop an eco-friendly tick control method, seven plant extracts were prepared using 50 and 95 % ethanol and evaluated for acaricidal activity against cattle tick, Rhipicephalus (Boophilus) microplus. The adult immersion test was adopted for testing different extracts. Based on 72 h screening criterion, 95 % ethanolic extracts of Datura metel fruits and Argemone mexicana whole plant were found effective showing more than 50 % mortality of treated ticks. The 95 % ethanolic extracts of D. metel fruits and A. mexicana whole plant exhibited acaricidal and reproductive inhibitory effects on treated ticks. The LC90 values of D. metel and A. mexicana extracts were determined as 7.13 and 11.3 %, respectively. However, although both the extracts were found efficacious against deltamethrin-resistant IVRI-4 and multi-acaricide resistant IVRI-5 lines of R. (B.) microplus, they caused less mortality than treated ticks of the reference IVRI-I line. Phytochemical studies indicated the presence of alkaloids and glucosides in D. metel fruits and alkaloids, terpenoids, flavonoids and phenolics in A. mexicana whole plant extracts. The results indicated that these botanicals may play an important role in reducing the use of chemicals for tick control and possibly to manage resistant tick population in environment friendly manner. PMID:25717008

Ghosh, Srikanta; Tiwari, Shashi Shankar; Kumar, Bhanu; Srivastava, Sharad; Sharma, Anil Kumar; Kumar, Sachin; Bandyopadhyay, A; Julliet, Sanis; Kumar, Rajesh; Rawat, A K S

2015-05-01

172

Synthesis of 2-aryl-3,4-dihydroisoquinolin-2-ium bromides and their in vitro acaricidal activity against Psoroptes cuniculi.  

PubMed

By employing sanguinarine, a natural active quaternary isoquinoline alkaloid, as a model molecule, a series of structurally simple quaternary 2-aryl-3,4-dihydroisoquinolin-2-ium compounds were designed and synthesized and evaluated for in vitro acaricidal activity against P. cuniculi. A new approach towards the title compounds was developed with isochroman as starting material. The results showed that 22 of 24 tested compounds displayed the activity in varying degrees at 0.4 mg/mL. Fourteen compounds were significantly more effective than ivermectin, a standard acaricide, and 6-methoxy dihydrosanguinarine, a derivative of sanguinarine (p<0.05). And their comprehensive relative activity was 1.4 to 16.5 times than that of ivermectin and 1.5 to 18.8 times than that of 6-methoxy dihydrosanguinarine. The structure-activity relationship indicated that the introduction of a substituent to N-benzene ring, especially halogen atom and trifluoromethyl group, led to great improvement of the activity. The position of fluorine atom, methyl group and hydroxyl group made very significant effects on the activity. It was concluded that 2-aryl-3,4-dihydroisoquinolin-2-iums are very promising candidates for the development of new isoquinoline acaricidal agents. PMID:23221611

Ma, Yan-Ni; Yang, Xin-Juan; Pan, Le; Hou, Zhe; Geng, Hui-Ling; Song, Xiao-Ping; Zhou, Le; Miao, Fang

2013-01-01

173

The ability of Pseudomonas sp. LBUM 223 to produce phenazine-1-carboxylic acid affects the growth of Streptomyces scabies, the expression of thaxtomin biosynthesis genes and the biological control potential against common scab of potato.  

PubMed

Streptomyces scabies causes common scab, an economical disease affecting potato crops world-wide, for which no effective control measure exists. This pathogen produces the plant toxin thaxtomin A, which is involved in symptom development on potato tubers. A biological control approach that can limit S. scabies growth and repress thaxtomin production represents an attractive alternative to classical control strategies. Pseudomonas sp. LBUM 223 produces phenazine-1-carboxylic acid (PCA), an antibiotic that inhibits the growth of plant pathogens and contributes to the biological control of plant diseases. In this study, the involvement of LBUM 223's PCA-producing ability in the growth inhibition of S. scabies, repression of thaxtomin biosynthesis genes (txtA and txtC) and the biological control of common scab of potato was investigated using a mutant defective in PCA production (LBUM 223phzC(-) ). Streptomyces scabies growth was inhibited to a significantly lesser degree by LBUM 223phzC(-) than by the wild type. LBUM 223 also significantly repressed txtA and txtC expression in S. scabies and protected potato against disease, whereas LBUM 223phzC(-) did not. These results suggest that PCA production is central to the ability of LBUM 223 to limit pathogen growth, repress the expression of key pathogenicity genes and control common scab of potato. PMID:21073487

St-Onge, Renée; Gadkar, Vijay J; Arseneault, Tanya; Goyer, Claudia; Filion, Martin

2011-01-01

174

Window contamination on Expose-R  

NASA Astrophysics Data System (ADS)

Expose is a multi-user instrument for astrobiological and astrochemical experiments in space. Installed at the outer surface of the International Space Station, it enables investigators to study the impact of the open space environment on biological and biochemical test samples. Two Expose missions have been completed so far, designated as Expose-E (Rabbow et al. 2012) and Expose-R (Rabbow et al. this issue). One of the space-unique environmental factors offered by Expose is full-spectrum, ultraviolet (UV)-rich electromagnetic radiation from the Sun. This paper describes and analyses how on Expose-R, access of the test samples to Solar radiation degraded during space exposure in an unpredicted way. Several windows in front of the Sun-exposed test samples acquired a brown shade, resulting in a reduced transparency in visible light, UV and vacuum UV (VUV). Post-flight investigations revealed the discolouration to be caused by a homogenous film of cross-linked organic polymers at the inside of the windows. The chemical signature varied per sample carrier. No such films were found on windows from sealed, pressurized compartments, or on windows that had been kept out of the Sun. This suggests that volatile compounds originating from the interior of the Expose facility were cross-linked and photo-fixed by Solar irradiation at the rear side of the windows. The origin of the volatiles was not fully identified; most probably there was a variety of sources involved including the biological test samples, adhesives, plastics and printed circuit boards. The outer surface of the windows (pointing into space) was chemically impacted as well, with a probable effect on the transparency in VUV. The reported analysis of the window contamination on Expose-R is expected to help the interpretation of the scientific results and offers possibilities to mitigate this problem on future missions - in particular Expose-R2, the direct successor of Expose-R.

Demets, R.; Bertrand, M.; Bolkhovitinov, A.; Bryson, K.; Colas, C.; Cottin, H.; Dettmann, J.; Ehrenfreund, P.; Elsaesser, A.; Jaramillo, E.; Lebert, M.; van Papendrecht, G.; Pereira, C.; Rohr, T.; Saiagh, K.

2015-01-01

175

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

176

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

177

Acaricidal activity of spinosad and abamectin against two-spotted spider mites.  

PubMed

Spinosad is a bioinsecticide with a high degree of selective toxicity towards insects of different orders, but its toxicity towards the two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae) is under debate. In this study, we compared the acaricidal properties of spinosad with the commercial bioacaricide abamectin on the life stages of TSSM. Adulticide and ovicide bioassays were performed on a susceptible laboratory strain using direct spraying of leaf disks with five rates of spinosad (20, 25, 30, 35 and 40 mg/l), five rates of abamectin (0.125, 0.25, 0.5, 1 and 2.5 mg/l), sublethal concentrations or a combination of spinosad and abamectin. Both adulticidal and ovicidal effects of spinosad against T. urticae in the laboratory were apparent, based on morality rates of the adults, reduction of female fecundity and death of offspring. Abamectin was also found to significantly reduce female fecundity and killed offspring when applied directly on the eggs. Interestingly, sublethal concentrations of spinosad reduced female fecundity stronger than abamectin. When a mixture of spinosad and abamectin was applied at LC50, mortality was 74%, fecundity reduction was comparable to abamectin alone and egg hatching rate was lower than by either compound alone. In conclusion, spinosad was more harmful than abamectin for TSSM life stages and the combined application is recommended. PMID:17899400

Ismail, Manal S M; Soliman, Maha F M; El Naggar, Moustafa H; Ghallab, Mona M

2007-01-01

178

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

179

Ethyl Cinnamate Derivatives as Promising High-Efficient Acaricides against Psoroptes cuniculi: Synthesis, Bioactivity and Structure-Activity Relationship.  

PubMed

This paper reported the synthesis, structure-activity relationship (SAR) and acaricidal activity in vitro against Psoroptes cuniculi, a mange mite, of 25 ethyl cinnamate derivatives. All target compounds were synthesized and elucidated by means of MS, (1)H- and (13)C-NMR analysis. The results showed that 24 out of 25 tested compounds at 1.0?mg/mL demonstrated acaricidal activity in varying degrees. Among them, 6, 15, 26, 27 and 30 showed significant activity with median lethal concentration values (LC50) of 89.3, 119.0, 39.2, 29.8 and 41.2?µg/mL, respectively, which were 2.1- to 8.3-fold the activity of ivermectin (LC50=247.4?µg/mL), a standard drug in the treatment of Psoroptes cuniculi. Compared with ivermectin, with a median lethal time value (LT50) of 8.9?h, 27 and 30 showed smaller LT50 values of 7.9 and 1.3?h, respectively, whereas 6, 15 and 26 showed slightly larger LT50 values of 10.6, 11.0 and 10.4?h at 4.5?µmol/mL. SARs showed that the presence of o-NO2 or m-NO2 on the benzene ring significantly improved the activity, whereas the introduction of a hydroxy, methoxy, acetoxy, methylenedioxy, bromo or chloro group reduced the activity. (E)-Cinnamates were more effective than their (Z)-isomer. Nevertheless, the carbon-carbon double bond in the acrylic ester moiety was proven not to be essential to improve the activity of cinnamic acid esters. Thus, the results strongly indicate that cinnamate derivatives, especially their dihydro derivatives, should be promising candidates or lead compounds for the development of novel acaricides for the effective control of animal or human acariasis. PMID:25739666

Zhang, Bingyu; Lv, Chao; Li, Weibo; Cui, Zhiming; Chen, Dongdong; Cao, Fangjun; Miao, Fang; Zhou, Le

2015-04-01

180

Effectiveness of selected granular acaricide formulations in suppressing populations of Ixodes dammini (Acari: Ixodidae): short-term control of nymphs and larvae.  

PubMed

Applications of selected granular acaricide formulations to the shrub layer of forested habitats during the peak activity periods of Ixodes dammini Spielman, Clifford, Piesman & Corwin nymphs and larvae significantly reduced the abundance of these stages on Peromyscus leucopus. The granules effectively penetrated growing vegetation and suppressed populations of subadult ticks questing in the leaf litter. The use of granular acaricide formulations provides the only documented method of control of free-living I. dammini nymphs and larvae in dense vegetation. As such, this technique will serve as a major component of any integrated control program against this vector tick species. PMID:1941929

Schulze, T L; Taylor, G C; Jordan, R A; Bosler, E M; Shisler, J K

1991-09-01

181

The effectiveness of some commercial acaricides for control of certain mites of the Tetranychus telarius complex attacking cotton  

E-print Network

!s. deedlin ?s to be used in the toxicity tests sero 21 grown in flats as previously descriLed. @hen the plants attaineoi the proper size, they ?ere pulled from the flats, washed. to remove loose sand. , treated, with an acaricide of known concentration...& be very effective in controllini. ; manv species of spider mites but their extreme toxicity to man and animals make those compounds difficult to handle and somewh t undesirable. The most prevalent specie of cotton-infesting mites i 1 a- etrstvc u d...

Fernandez, Alberto Thomas

1959-01-01

182

Acaricidal and quantitative structure activity relationship of monoterpenes against the two-spotted spider mite, Tetranychus urticae  

Microsoft Academic Search

The acaricidal activity of 12 monoterpenes against the two-spotted spider mite, Tetranychus urticae Koch, was examined using fumigation and direct contact application methods. Cuminaldehyde and (?)-linalool showed the highest\\u000a fumigant toxicity with LC50 = 0.31 and 0.56 mg\\/l, respectively. The other monoterpenes exhibited a strong fumigant toxicity, the LC50 values ranging from 1.28 to 8.09 mg\\/l, except camphene, which was the least effective (LC50 = 61.45 mg\\/l).

Mohamed E. I. Badawy; Sailan A. A. El-Arami; Samir A. M. Abdelgaleil

2010-01-01

183

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

184

Tick control practices in Burkina Faso and acaricide resistance survey in Rhipicephalus (Boophilus) geigyi (Acari: Ixodidae).  

PubMed

Traditional systems account for 95 % of the livestock produced in Burkina Faso. Tick infestation hampers livestock productivity in this area. However, little information exists on tick-control practices used by livestock farmers. We interviewed 60 stockbreeders working in traditional farming systems to obtain the first data on tick-control practices. Sixteen farmers (27 %) did not use conventional practices: seven removed ticks by hand or plastered cattle with dung or engine oil; nine farmers treated cattle with crop pesticides. Forty-four farmers (73 %) used mainly synthetic pyrethroids (SP; either alphacypermethrin or deltamethrin in 20 and 18 farms, respectively) and occasionally amitraz (N = 6). Intervals between treatments varied significantly depending on the chemical used: most farmers using crop pesticides (100 %), amitraz (100 %) or alphacypermethrin (80 %) adjusted tick-control to tick-burden, whereas farmers using deltamethrin tended more to follow a tick-control schedule. Perception of tick-control effectiveness significantly varied among practices: tick-control failures were more frequently reported by farmers using alphacypermethrin (55 %) than by those using either other conventional acaricides (17 %) or crop pesticides (0 %). We investigated whether this could indicate actual development of SP-resistance in cattle ticks. First, using the larval packet test technique, we confirmed that the computation of LC50 and LC90 was repeatable and remained stable across generations of the Rhipicephalus (Boophilus) geigyi Houndé laboratory strain. We then collected from the field fully-engorged female R. geigyi to evaluate the SP-resistance relative to the Houndé reference strain. We did not detect any case of SP-resistance in the field-derived R. geigyi ticks. PMID:22968469

Adakal, Hassane; Stachurski, Frédéric; Chevillon, Christine

2013-04-01

185

EXPOSE-R cosmic radiation time profile  

NASA Astrophysics Data System (ADS)

The aim of the paper is to present the time profile of cosmic radiation exposure obtained by the radiation risks radiometer-dosimeter (R3DR) during the ESA exposition facility for EXPOSE-R mission (EXPOSE-R) in the EXPOSE-R facility outside the Russian Zvezda module of the International Space Station (ISS). Another aim is to make the obtained results available to other EXPOSE-R teams for use in their data analysis. R3DR is a low mass and small dimensions automated device, which measures solar radiation in four channels and in addition cosmic ionizing radiation. The main results of cosmic ionizing radiation measurements are: three different radiation sources were detected and quantified: galactic cosmic rays (GCR), energetic protons from the inner radiation belt (IRB) in the region of the South Atlantic anomaly and energetic electrons from the outer radiation belt (ORB). The highest daily averaged absorbed dose rate of 506 ?Gy day-1 came from IRB protons; GCR delivered much smaller daily absorbed dose rates of 81.4 ?Gy day-1 on average, and ORB source delivered on average a dose rate of 89 ?Gy day-1. The IRB and ORB daily averaged absorbed dose rates were higher than those observed during the ESA exposition facility for EXPOSE-E mission (EXPOSE-E), whereas the GCR rate was smaller than that measured during the EXPOSE-E mission. The reason for this difference is much less surrounding constructions shielding of the R3DR instrument in comparison with the R3DE instrument.

Dachev, Tsvetan; Horneck, Gerda; Häder, Donat-Peter; Schuster, Martin

2015-01-01

186

Biofunctional constituent isolated from Citrullus colocynthis fruits and structure-activity relationships of its analogues show acaricidal and insecticidal efficacy.  

PubMed

The acaricidal and insecticidal potential of the active constituent isolated from Citrullus colocynthis fruits and its structurally related analogues was evaluated by performing leaf disk, contact toxicity, and fumigant toxicity bioassays against Tetranychus urticae, Sitophilus oryzae, and Sitophilus zeamais adults. The active constituent of C. colocynthis fruits was isolated by chromatographic techniques and was identified as 4-methylquinoline on the basis of spectroscopic analyses. To investigate the structure-activity relationships, 4-methylquinoline and its structural analogues were tested against mites and two insect pests. On the basis of the LC50 values, 7,8-benzoquinoline was the most effective against T. urticae. Quinoline, 8-hydroxyquinoline, 2-methylquinoline, 4-methylquinoline, 6-methylquinoline, 8-methylquinoline, and 7,8-benzoquinoline showed high insecticidal activities against S. oryzae and S. zeamais regardless of the application method. These results indicate that introduction of a functional group into the quinoline skeleton and changing the position of the group have an important influence on the acaricidal and insecticidal activities. Furthermore, 4-methylquinoline isolated from C. colocynthis fruits, along with its structural analogues, could be effective natural pesticides for managing spider mites and stored grain weevils. PMID:25110971

Jeon, Ju-Hyun; Lee, Hoi-Seon

2014-08-27

187

Acaricidal activity against Panonychus citri of a ginkgolic acid from the external seed coat of Ginkgo biloba.  

PubMed

An acaricidal substance extracted from the external seed coat of Ginkgo biloba L. was identified by UV (ultraviolet), IR (infrared), EI-MS (electron impact ion source mass spectrometry), (1)H NMR (nuclear magnetic resonance) and (13)C NMR as 6-[(Z)-10-heptadecenyl]-2-hydroxybenzoic acid (compound 1). Laboratory bioassay on citrus red mite, Panonychus citri (Mcg), showed that compound 1 possessed the following properties. (i) Powerful contact toxicity with an LC(50) of 5.2 mg litre(-1) after 24 h that was similar to that of pyridaben (LC(50) = 3.4 mg litre(-1)) and significantly superior to that of omethoate (LC(50) = 122 mg litre(-1)). Furthermore, its LC(90) was 13.4 mg litre(-1) after 24 h, which is significantly superior to both pyridaben (LC(90) = 69.6 mg litre(-1)) and omethoate (LC(90) = 453 mg litre(-1)). (ii) Quick-acting acaricidal activity. At identical concentrations, compound 1 was much faster-acting than pyridaben or omethoate. (iii) Compound 1 had strong corrosive action on the cuticle of P. citri but no phytotoxicity to plants. PMID:16475219

Pan, Weigao; Luo, Peng; Fu, Ruobin; Gao, Ping; Long, Zhangfu; Xu, Feiyi; Xiao, Haibo; Liu, Shigui

2006-03-01

188

Food protective effect of acaricidal components isolated from anise seeds against the stored food mite, Tyrophagus putrescentiae (Schrank).  

PubMed

The acaricidal activity of anise seed-isolated anisaldehyde and commercially available components of anise seed was examined against Tyrophagus putrescentiae adults and compared with those of synthetic acaricides, benzyl benzoate, dibutyl phthalate, and N,N-diethyl-m-toluamide (DEET). On the basis of LD50 (50% lethal dose) values, the compound most toxic to T. putrescentiae adults was anisaldehyde (LD50, 0.96 microg/cm2), followed by benzyl benzoate (LD50, 11.3 microg/cm2), anethole (LD50, 12.3 microg/cm2), dibutyl phthalate (LD50, 13.3 microg/cm2), DEET (LD50, 13.5 microg/cm2), estragole (LD50, 17.4 microg/cm2), and myrcene (LD50, 56.2 microg/cm2). Anisaldehyde was about 11.8 and 14 times more toxic than benzyl benzoate and DEET against T. putrescentiae adults, respectively. The results suggested that anisaldehyde, anethole, estragole, and myrcene derived from anise seeds are useful as a lead compound to development new agents for selective control of the stored food mite. PMID:15954709

Lee, Hoi-Seon

2005-06-01

189

Laboratory assessment of acaricidal activity of Cymbopogon winterianus, Vitex negundo and Withania somnifera extracts against deltamethrin resistant Hyalomma anatolicum.  

PubMed

Larval packet test was used for detection of resistance levels against cypermethrin and deltamethrin, the most commonly used synthetic pyrethroids, in the multi-host tick Hyalomma anatolicum collected from district Moga, Punjab (India). Results indicated the presence of level I resistance against deltamethrin (RF = 2.81), whereas the tick isolate was susceptible to cypermethrin (RF = 0.2). The aqueous and ethanolic extracts of leaves of Cymbopogon winterianus, Vitex negundo and Withania somnifera along with roots of Vitex negundo were assessed for their acaricidal activity against the larvae of deltamethrin resistant H. anatolicum. The efficacy was assessed by measuring per cent larval mortality and determination of LC50 values. The various ethanolic extracts produced a concentration dependent increase in larval tick mortality, whereas the aqueous extracts exhibited a much lower mortality. The highest mortality (93.7 ± 0.66 %) was observed at the 5.0 % concentration of ethanolic extract of leaves of C. winterianus and the lowest LC50 value (0.011 %) was recorded for ethanolic extracts of leaves of V. negundo. The results indicated that these plant extracts have potential to be developed as herbal acaricides. PMID:24647800

Singh, Nirbhay Kumar; Jyoti; Vemu, Bhaskar; Nandi, Abhijit; Singh, Harkirat; Kumar, Rajender; Dumka, V K

2014-07-01

190

A survey of fipronil- and ivermectin-resistant Rhipicephalus (Boophilus) microplus collected in Northern Mexico and the options for the management of acaricide-resistant ticks with pesticides  

Technology Transfer Automated Retrieval System (TEKTRAN)

Six strains of Rhipicephalus (Boophilus) microplus collected from northern Mexico were surveyed for resistance to 5 classes of acaricide. All were resistant to permethrin. Two strains were resistant to amitraz and 3 were found to be resistant to coumaphos. Two strains were resistant to fipronil incl...

191

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

192

Acaricidal Treatment of White-Tailed Deer to Control Ixodes Scapularis (Acari: Ixodidae) in a New York Lyme Disease-Endemic Community  

Technology Transfer Automated Retrieval System (TEKTRAN)

The 4-Poster device for the topical treatment of white-tailed deer, Odocoileus virginianus (Zimmermann) against ticks using the acaricide amitraz was evaluated in a Lyme borreliosis endemic community in Connecticut. As part of a 5-year project from 1997 to 2002, 21–24 of the 4-Posters were distribut...

193

Topical Treatment of White-Tailed Deer with an Acaricide for the Control of Ixodes Scapularis (Acari: Ixodidae) in a Connecticut Lyme Borreliosis Hyperendemic Community  

Technology Transfer Automated Retrieval System (TEKTRAN)

The 4-Poster device for the topical treatment of white-tailed deer, Odocoileus virginianus (Zimmermann), against ticks using the acaricide amitraz, was evaluated in a Lyme borreliosis endemic community in Connecticut. As part of a 5-year project from 1997 to 2002, 21–24 of the 4-Posters were distrib...

194

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

195

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

196

Acaricidal activity of the essential oil from Tetradenia riparia (Lamiaceae) on the cattle tick Rhipicephalus (Boophilus) microplus (Acari; Ixodidae).  

PubMed

Tetradenia riparia (Lamiaceae) is a well-known herbal medicine with a variety of useful properties, including its acaricidal effect. This experiment was carried out to study the bioacaricidal activity of T. riparia essential oil (EO) against engorged females of Rhipicephalus (Boophilus) microplus (Acari; Ixodidae). For this purpose, nine serial concentrations (12.50%, 6.25%, 3.75%, 1.80%, 0.90%, 0.45%, 0.22%, 0.11%, and 0.056% w/v) of T. riparia were used for the adult immersion test (AIT). For the larval packet test (LPT), we used 14 serial concentrations (100.00%, 50.00%, 25.00%, 12.50%, 6.25%, 3.65%, 1.82%, 0.91%, 0.45%, 0.228%, 0.114%, 0.057%, 0.028%, and 0.014% w/v). The results for AIT showed 100.00% and 2.05% mortality, 19.00 and 90.20% for the total number of eggs, egg-laying inhibition of 0.00% and 90.20%, hatchability inhibition of 0.00% and 70.23%, and product effectiveness of 100.00% and 2.89%, respectively. The AIT indicated that the LC(50) and LC(99.9), calculated using the Probit test, were for mortality (%) 0.534g/mL (0.436-0.632) and 1.552g/mL (1.183-1.92); for total number of eggs were 0.449g/mL (0.339-0.558) and 1.76g/mL (1.27-2.248); and for hatchability inhibition were 0.114g/mL (0.0-0.31) and 2.462g/mL (1.501-3.422), respectively. Larvae between 14 and 21days old were fasted and placed in each envelope. Bioassays were performed at 27°±1°C, RH?80%. Larval mortality was observed 24h after treatment and showed 10.60-100% mortality in the LPT bioassay. The LPT showed that the LC(50) and LC(99.9) were 1.222g/mL (0.655-1.788) and 11.382g/mL (7.84-14.91), respectively. A positive correlation between T. riparia EO concentration and tick control, was observed by the strong acaricidal effects against R. (B.) microplus, and the mortality rate of ticks was dose-dependent. Our results showed that T. riparia is a promising candidate as an acaricide against resistant strains of R. (B.) microplus. PMID:21762693

Gazim, Zilda Cristiani; Demarchi, Izabel Galhardo; Lonardoni, Maria Valdrinez Campana; Amorim, Ana Carolina L; Hovell, Ana Maria C; Rezende, Claudia Moraes; Ferreira, Gilberto Alves; de Lima, Edson Luiz; de Cosmo, Fábio Antunes; Cortez, Diogenes Aparício Garcia

2011-10-01

197

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

198

Acaricidal properties of two extracts from Guiera senegalensis J.F. Gmel. (Combrataceae) against Hyalomma anatolicum (Acari: Ixodidae).  

PubMed

Laboratory test were carried out on eggs, larvae, nymphs and adults of Hyalomma anatolicum to determine the acaricidal activities of petroleum ether (PE) and crude ethanolic extracts (EE) from the leaves of Guiera senegalensis J.F. Gmel. (Combrataceae) using immersion method. Stock solutions, of 300 mg/ml (30%) of the each two extract, were prepared. Six two-fold serial dilutions each with three replicates were used. Both extracts, at the highest concentration 150 mg/ml (15%), induced 100% failure of hatching of the treated eggs. The concentrations of PE and EE that induced 50% inhibition of the hatchability (IC50) were 1.71 and 0.508%, respectively. In the larval immersion test (LIT), EE at 15% concentration caused complete mortality while the same concentration of PE resulted in 96% mortality. The mortalities increased with concentrations. There was a correlation between the mortalities and increased concentrations, the values of the linear correlation coefficient (r) for PE and EE were 0.93 and 0.79, and The LC50 and LC99 were 2.08 and 14.09, and 0.787 and 11.054, respectively. At the concentrations of 3.75%, 7.5% and 15%, PE inhibited the molting of the nymphs by 40, 55 and 65%, respectively, while EE induced 46.49, 64.3 and 71.4% inhibition, respectively. The effectiveness of the treatment against unfed adult females was assessed by measuring the feeding performance and egg production using adult immersion test (AIT). Although, there was no mortality in unfed adults, PE and EE inhibited feeding and egg-laying of the survived females by 35-100% and 6.16-100%, respectively. Our results indicated that G. senegalensis is a promising biocontrol candidate as an acaricidal agent against H. anatolicum. PMID:24315188

Osman, Ilham M; Mohammed, A S; Abdalla, A B

2014-01-31

199

Scabies (For Parents)  

MedlinePLUS

... allow bacteria to get into the injured skin. Impetigo , a bacterial skin infection, may affect skin that's ... also develops a bacterial skin infection (such as impetigo) and an antihistamine to help relieve the itching. ...

200

Travelers' Health: Scabies  

MedlinePLUS

... for Education Purposes and the Ebola Outbreak in West Africa Sun Exposure Swimming and Diving Travelers' Diarrhea Travelers ... in the American Tropics? Ebola Outbreak - Recently in West Africa? Ebola Outbreak - Going to West Africa? Traveler Survival ...

201

Scabies: Signs and Symptoms  

MedlinePLUS

... resources My account Patient education resources Awards, grants, scholarships State society resources Become a member Meetings and ... use criteria MOC Patient safety Awards, grants and scholarships CME transcripts About AAD Recognized Credit Basic Dermatology ...

202

Scabies: Tips for Managing  

MedlinePLUS

... resources My account Patient education resources Awards, grants, scholarships State society resources Become a member Meetings and ... use criteria MOC Patient safety Awards, grants and scholarships CME transcripts About AAD Recognized Credit Basic Dermatology ...

203

Control of tuber-borne black scurf [Rhizoctonia solani] and common scab [Streptomyces scabies] of potatoes with a combination of sodium hypochlorite and thiophanate-methyl preplanting seed tuber treatment  

Microsoft Academic Search

In a 2-year field experiment, preplanting seed tuber treatments with sodium hypochlorite solution (as NaOCl 500 ppm for 8 min), thiophanate-methyl (TPM; as Easout™, 50 g active ingredients\\/100 kg seed tubers), or a combination treatment with NaOCl followed by TPM were evaluated for control of black scurf, caused by Rhizoctonia solani Kühn, and common scab, caused by Streptomyces scabies (Thaxter)

Deena Errampalli; H. Winston Johnston

2001-01-01

204

Acaricidal effect and chemical composition of essential oils extracted from Cuminum cyminum , Pimenta dioica and Ocimum basilicum against the cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)  

Microsoft Academic Search

Acaricidal activity of essential oils extracted from cumin seeds (Cuminum cyminum), allspice berries (Pimenta dioica) and basil leaves (Ocimum basilicum) were tested on 10-day-old Rhipicephalus (Boophilus) microplus tick larvae using the LPT. Two-fold dilutions of the three essential oils were tested from a starting dilution of 20% down\\u000a to 1.25%. Results showed a high toxicological effect for cumin, producing 100%

Moises Martinez-Velazquez; Gustavo Adolfo Castillo-Herrera; Rodrigo Rosario-Cruz; Jose Miguel Flores-Fernandez; Julisa Lopez-Ramirez; Rodolfo Hernandez-Gutierrez; Eugenia del Carmen Lugo-Cervantes

2011-01-01

205

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

206

Acaricide and ivermectin resistance in a field population of Rhipicephalus microplus (Acari: Ixodidae) collected from red deer (Cervus elaphus) in the Mexican tropics.  

PubMed

In the Neotropics the control of tick infestations in red deer (Cervus elaphus) is achieved primarily through the use of acaricides and macrocyclic lactones. In Mexico, resistance to one or multiple classes of acaricides has been reported in Rhipicephalus microplus infesting cattle, but information on acaricide susceptibility in R. microplus infesting red deer is lacking. In this study we report the level of resistance to different classes of acaricides and ivermectin in R. microplus collected from red deer in the Mexican tropics. Engorged R. microplus females were collected from a red deer farm in Yucatan, Mexico. The larval packet test was used to detect resistance to the organophosphates (OPs) chlorpyrifos and coumaphos, synthetic pyrethroids (SPs) cypermethrin and permethrin, and the phenylpyrazol, fipronil. Resistance to the formamidine amitraz (Am), and ivermectin was ascertained using the larval immersion test. Data were subjected to probit analysis to determine lethal concentrations and resistance ratios to kill 50% (RR50) and 99% (RR99) of the tick population under evaluation in relation to susceptible reference strains. Additionally, allele specific polymerase chain reaction was used to detect the sodium channel F1550I mutation associated with SP resistance in R. microplus. The R. microplus population from red deer in Yucatan showed very high resistance to the two SPs evaluated (RRs>72.2 for cypermethrin; RR for permethrin resistance was so high a dose-response curve was not possible). All individual larvae tested to detect the sodium channel F1550I mutation associated with SP resistance in R. microplus were homozygous. The same tick population showed different levels of resistance to OPs (chlorpyrifos: RR50=1.55, RR99=0.63; coumaphos: RR50=6.8, RR99=5.9), fipronil (RR50=1.8, RR99=0.9), and amitraz (RR50=2.3, RR99=4.4). Resistance to ivermectin was regarded as moderate (RR50=7.1, RR99=5.0). This is the first report of R. microplus ticks collected from red deer in Mexico with different levels of resistance to four acaricide groups and ivermectin. PMID:24365245

Rodríguez-Vivas, R I; Miller, R J; Ojeda-Chi, M M; Rosado-Aguilar, J A; Trinidad-Martínez, I C; Pérez de León, A A

2014-02-24

207

In vitro acaricidal activity of neem (Azadirachta indica) seed extracts with known azadirachtin concentrations against Rhipicephalus microplus.  

PubMed

The effect of four extracts from neem seeds (Azadirachta indica) containing 2000, 5000, 9000 and 10,000 ppm of azadirachtin A (AZA), quantified by high-performance liquid chromatography (HPLC) and diluted to 1.25%; 2.5%; 5.0%; 10.0% and 12.8% was verified by in vitro tests with engorged females and larvae of the cattle tick Rhipicephalus microplus. The results from the bioassays with the engorged females showed that the main toxic effect of the extracts was reduction of the reproductive parameters, with a sharp drop in the number of eggs laid and the hatching rate, mainly when the extracts were diluted to 10.0% and 12.8%. The product effectiveness (PE) calculations for all the solutions tested showed that the AZA solution at 10,000 ppm (N10) was the most effective. However, statistical analysis of the PE data obtained for the proportional AZA concentrations in the different diluted extracts showed significance (P<0.05) of the effects included in the model (extract dilution, principle effect (classificatory) of the assay (extract) and the interaction between the two), indicating significant variations due to the dilution, the test and the interaction between the two factors in the tests with engorged females. For solutions N2, N5, and N9, it was not possible to estimate LC(90) values in the dilution range tested. The lowest LC(50) was observed for extract N5, and although extract N10 was the only extract for which the LC(90) could be estimated within the range tested, the LC(50) was higher than for N5 and N9. These results suggest that substances other than AZA present in the extracts influenced the efficacy, especially up to a certain LC range. In the tests with larvae, no mortality was observed, indicating zero effectiveness of all the extracts tested. The results of the tests with engorged females showed that the neem extracts had acaricide activity, inhibiting egg laying and the larval hatching rate. Complementary studies are necessary to develop new methods to isolate and/or identify other substances besides AZA contained in this plant, to enable using products made from it as acaricides. PMID:21536387

Giglioti, R; Forim, M R; Oliveira, H N; Chagas, A C S; Ferrezini, J; Brito, L G; Falcoski, T O R S; Albuquerque, L G; Oliveira, M C S

2011-09-27

208

In vitro acaricidal activity of Murraya koenigii (L.) Spreng (Rutaceae) extracts against synthetic pyrethroid-resistant Rhipicephalus (Boophilus) microplus.  

PubMed

Larval packet test was used for detection of resistance status against cypermethrin and deltamethrin, the most commonly used synthetic pyrethroids in Rhipicephalus (Boophilus) microplus collected from Faridkot district, Punjab (India). The slope of mortality, lethal concentration for 50 % (LC50) and resistance levels were determined from the regression graphs of probit mortality of ticks plotted against log values of increasing concentrations of cypermethrin and deltamethrin. Results indicated presence of resistance of levels I and II against cypermethrin (resistance factor (RF)?=?2.82) and deltamethrin (RF?=?8.44), respectively. Adult immersion test was used to assess the acaricidal activity of aqueous (MLAq), ethanol (MLE), chloroform (MLC), acetone (MLA) and hexane (MLH) extracts of leaves of Murraya koenigii against these synthetic pyrethroid (SP)-resistant engorged adult females of R. (B.) microplus by determination of per cent adult mortality, reproductive index (RI), per cent inhibition of oviposition (%IO) and hatching rate. The per cent mortality caused by various extracts at concentrations ranging from 0.625 to 10.0 % varied from 0.0 to 100.0 % with maximum per cent mortality of 10.0, 100.0, 70.0, 40.0 and 10.0 recorded against MLAq, MLE, MLC, MLA and MLH, respectively. Among all extracts, the highest acaricidal property against SP-resistant R. (B.) microplus was exhibited by the MLE as it showed the minimum LC50 [95 % confidence limit (CL)] values of 2.97 % (2.82-3.12 %), followed by MLC as 10.26 % (8.84-11.91 %) and MLA as 18.22 % (16.18-20.52 %). The average egg mass weight recorded in live ticks treated with various concentrations of different extracts was lower than the respective control group ticks and was significantly (p?

Singh, Nirbhay Kumar; Jyoti; Vemu, Bhaskar; Singh, Harkirat; Prerna, Mranalini; Daundkar, Prashant S; Sharma, S K; Dumka, V K

2015-04-01

209

Acaricidal activity of Cymbopogon winterianus, Vitex negundo and Withania somnifera against synthetic pyrethroid resistant Rhipicephalus (Boophilus) microplus.  

PubMed

Detection of resistance levels against cypermethrin and deltamethrin, the most commonly used synthetic pyrethroids (SPs) against Rhipicephalus (Boophilus) microplus collected from Moga, Punjab (India) was carried out using larval packet test. Results indicated the presence of resistance of level I and III against cypermethrin (resistance factors (RF) = 4.67) and deltamethrin (RF = 34.2), respectively. Adult immersion test was used to assess the acaricidal activity of aqueous and ethanolic extracts of leaves of Cymbopogon winterianus, Vitex negundo, and Withania somnifera along with roots of V. negundo against the SP resistant engorged females of R. (B.) microplus. The efficacy of various extracts was assessed by estimation of percent adult mortality, reproductive index (RI), percent inhibition of oviposition (%IO), and hatching rate. A concentration dependent increase in tick mortality was recorded which was more marked with various ethanolic extracts, and highest mortality was recorded in ticks treated with ethanolic extract of leaves of C. winterianus. The LC50 values were determined by applying regression equation analysis to the probit transformed data of mortality for various aqueous and ethanolic extracts. Acaricidal property was recorded to be higher in ethanolic extracts, and high activity was found with the ethanolic extract of leaves of C. winterianus with LC50 (95% CL) values of 0.46% (0.35-0.59%), followed by W. somnifera as 5.21% (4.45-6.09%) and V. negundo as 7.02% (4.58-10.74%). The egg mass weight of the live ticks treated with different concentrations of the various extract was significantly (p < 0.01) lower than that of control ticks; consequently, the RI and the %IO value of the treated ticks were reduced. Further, complete inhibition of hatching was recorded in eggs laid by ticks treated with ethanolic extracts of leaves of V. negundo and aqueous extracts of leaves of W. somnifera. The results of the current study indicate that extracts of C. winterianus, V. negundo, and W. somnifera can be used for the control of SP resistant ticks. PMID:24178747

Singh, Nirbhay Kumar; Jyoti; Vemu, Bhaskar; Nandi, Abhijit; Singh, Harkirat; Kumar, Rajender; Dumka, V K

2014-01-01

210

A new in vitro test to evaluate the resistance level against acaricides of the cattle tick, Rhipicephalus (Boophilus) microplus.  

PubMed

In this article we present a new bioassay to assess the resistance status of ticks to acaricides. The Larval Tarsal Test (LTT) is a sensitive, highly time-effective in vitro test. It allows the investigation of a large number of compounds and doses on the cattle tick Rhipicephalus (Boophilus) microplus in a short period of time. The ability of the LTT to assess the lethal concentration at 50% mortality (LC(50)) and resistance ratios (RRs) of a susceptible and a resistant R. microplus strain was compared with the FAO-recommended Larval Packet Test (LPT). Representative compounds of the carbamate, organophosphate (OP), synthetic pyrethroid (SP), formamidine (FOR), macrocyclic lactone and pyrazole classes were used for this comparison. The resistance status against OP, SP and FOR of the resistant R. microplus strain was confirmed in vivo. The LTT resulted in resistance ratios comparable to those obtained with the LPT. However, the lethal concentrations were up to 150-fold lower in the LTT than in the LPT. The advantage of the LTT is to simplify the methodology by avoiding the handling of larvae and using multi-well plates. The LTT is therefore a suitable test for the assessment of the level of resistance of R. microplus and is very promising to evaluate the resistance profile of field strains. Additionally, the LTT is also suitable to test other ixodid species. PMID:21741175

Lovis, L; Perret, J-L; Bouvier, J; Fellay, J-M; Kaminsky, R; Betschart, B; Sager, H

2011-12-15

211

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

212

Disruption of sscR encoding a gamma-butyrolactone autoregulator receptor in Streptomyces scabies NBRC 12914 affects production of secondary metabolites.  

PubMed

We report the cloning and sequence analysis of a gamma-butyrolactone autoregulator regulatory island that includes an sscR gene encoding the gamma-butyrolactone autoregulator receptor from Streptomyces scabies NBRC 12914, a plant pathogenic strain. gamma-Butyrolactone autoregulators trigger secondary metabolism, and sometimes morphological differentiation in the Gram-positive genus Streptomyces through binding to a specific autoregulator receptor. This gene cluster showed close similarity to other regulatory islands of Streptomyces origin that are responsible for the control of secondary metabolism. The recombinant SscR protein expressed in Escherichia coli prefers a gamma-butyrolactone autoregulator containing a long C-2 side chain and beta-hydroxyl group at the C-6 position. An inactivation experiment confirmed that this gamma-butyrolactone autoregulator receptor was involved in secondary metabolism but had no effects on the morphological differentiation. In the sscR-deleted mutant, the binding activity of the gamma-butyrolactone autoregulator was completely abolished, suggesting that its primary role is to detect the presence of an autoregulator in the environment. HPLC analysis of the culture broth showed that some peaks disappeared and new peaks that were not present in the broth of the wild-type strain appeared. PMID:18500630

Kitani, S; Hoshika, M; Nihira, T

2008-01-01

213

Acaricidal activity of essential oil from Lippia sidoides on unengorged larvae and nymphs of Rhipicephalus sanguineus (Acari: Ixodidae) and Amblyomma cajennense (Acari: Ixodidae).  

PubMed

The aims of this work were to identify the compounds and to investigate the acaricidal activity of the essential oil of Lippia sidoides for unengorged larvae and nymphs of Rhipicephalus sanguineus and Amblyomma cajennense. The oil was analyzed by gas chromatography and gas chromatography/mass spectrometry. In total, 22 compounds comprising 98.5% of the total peak area were identified. The major constituent of the essential oil was thymol (69.9%). The acaricidal activity against larvae and nymphs was assessed using a modified larval packet test. In all experiments, oils were tested at concentrations of 2.35, 4.70, 9.40 14.10 and 18.80 mg/mL. The mortalities of larvae and nymphs of R. sanguineus were 20.6, 47.8, 73.6, 99.5 and 99.0% and 12.0, 50.0, 76.3, 96.0 and 96.1%, respectively. For larvae and nymphs of A. cajennense the rates of mortality were 41.9, 63.3, 77.8, 82.5 and 100.0% and 0.0, 32.8, 64.8, 71.1 and 94.0%, respectively. The LC 90 values of the L. sidoides oil were 11.56 and 12.97 mg/mL for larvae and nymphs of R. sanguineus and 15.70 and 18.52 mg/mL for larvae and nymphs of A. cajennense, respectively. The essential oil from L. sidoides has acaricidal activity on unengorged larvae and nymphs of R. sanguineus and A. cajennense. PMID:24333789

Gomes, Geovany Amorim; Monteiro, Caio Márcio Oliveira; Julião, Lisieux de Santana; Maturano, Ralph; Senra, Tatiane Oliveira Souza; Zeringóta, Viviane; Calmon, Fernanda; Matos, Renata da Silva; Daemon, Erik; Carvalho, Mario Geraldo de

2014-02-01

214

The acaricidal efficacy of peracetic acid and deltamethrin against the fowl tick, Argas persicus, infesting laying hens.  

PubMed

The fowl tick, Argas persicus (Oken), is of veterinary importance as a parasite of poultry and wild birds. The antitick efficacy, in vitro and in vivo, of peracetic acid (PAA) and deltamethrin (DMT) was tested separately against A. persicus through the dipping technique. PAA (0.5 %) was highly efficient against soft tick larvae (A. persicus), resulting in 100 % mortality after 2 min. The lethal concentrations LC(50) and LC(95) were 0.310 and 0.503 %, respectively. The lethal time values LT(50) and LT(95) were 5.34 and 40.00 min, respectively, after treatment with PAA (0.25 %). Two minutes after exposure to DMT, LC(50) and LC(95) values were 0.033 and 0.052 % (33.204 and 51.527 mg/L), respectively. The LT(50) and LT(95) values were 27.03 and 305.46 min, respectively, after treatment with 0.025 % DMT (25 mg/L). After dipping in PAA (0.5 %), the chickens did not show respiratory signs or inflammation on the eyes and/or skin. By contrast, temporary coughing, sneezing, and ocular inflammations without dermatitis were observed in chickens dipped in DMT (0.05 % or 50 mg /L). Seven days posttreatment (PT), the reduction in the percentages of A. persicus infesting laying hens were 99.15 and 63.42 % after dipping in PAA and DMT, respectively. However, complete elimination of the number of ticks occurred after 28 days PT with DMT. PAA inhibits molting effectively (28 %) when compared with that of DMT (52 %). Results indicated that PAA is a more potent and promising acaricide against A. persicus (in vitro and in vivo) than DMT. PMID:23090722

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

2013-01-01

215

Evaluation of benzaldehyde derivatives from Morinda officinalis as anti-mite agents with dual function as acaricide and mite indicator  

PubMed Central

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS virus with 12–30% fatality rate. Despite severity of the disease, any medication or treatment for SFTS has not developed yet. One approach to prevent SFTS spreading is to control the arthropod vector carrying SFTS virus. We report that 2–methylbenzaldehyde analogues from M. officinalis have a dual function as acaricide against Dermatophagoides spp. and Haemaphysalis longicornis and indicator (color change) against Dermatophagoides spp. Based on the LD50 values, 2,4,5–trimethylbenzaldehyde (0.21, 0.19, and 0.68??g/cm3) had the highest fumigant activity against D. farinae, D. pteronyssinus, and H. longicornis, followed by 2,3–dimethylbenzaldehyde (0.46, 0.44, and 0.79??g/cm3), 2,4–dimethylbenzaldehyde (0.66, 0.59, and 0.95??g/cm3), 2,5–dimethylbenzaldehyde (0.65, 0.68, and 0.88??g/cm3), 2–methylbenzaldehyde (0.95, 0.87, and 1.28??g/cm3), 3–methylbenzaldehyde (0.99, 0.93, and 1.38??g/cm3), 4–methylbenzaldehyde (1.17, 1.15, and 3.67??g/cm3), and M. officinalis oil (7.05, 7.00, and 19.70??g/cm3). Furthermore, color alteration of Dermatophagoides spp. was shown to be induced, from colorless to dark brown, by the treatment of 2,3–dihydroxybenzaldehyde. These finding indicated that 2–methylbenzaldehyde analogues could be developed as functional agent associated with the arthropod vector of SFTS virus and allergen. PMID:25434408

Yang, Ji-Yeon; Kim, Min-Gi; Park, Jun-Hwan; Hong, Seong-Tshool; Lee, Hoi-Seon

2014-01-01

216

Use of polymerase chain reaction: Restriction fragment length polymorphism to detect acaricidal resistance to synthetic pyrethroids in Boophilus microplus ticks of South India  

PubMed Central

Background: Boophilus microplus is an important ectoparasite of livestock. Apart from transmitting diseases, heavy tick burden can decrease production and damage hides. The synthetic pyrethroids which are advantageous over other acaricides for treatment of this infestation are now losing their efficacy due to development of resistant strains of ticks. Materials and Methods: Boophilus microplus ticks with a previous history of acaricidal treatment especially synthetic pyrethroids (SP) such as cypermethrin, deltamethrin and flumethrin were randomly collected from different pockets of four Southern States of India namely Tamil Nadu, Kerala, Karnataka, Andhra Pradesh, and Puducherry from cattle. Deoxyribonucleic acid extracted from pooled adult B. microplus tick from each State was subjected to polymerase chain reaction-restriction fragment length polymorphism to detect point mutation in carboxyl esterase gene. Results: A product size of 372 bp was obtained for cattle tick samples collected from all over Southern States of India. Conclusions: B. microplus ticks found in Southern part of India are not resistant to commonly used SP. PMID:23961446

Cattavarayane, Mathivathani; Basith, Abdul; Latha, Bhaskaran Ravi

2013-01-01

217

Acaricidal effect and chemical composition of essential oils extracted from Cuminum cyminum, Pimenta dioica and Ocimum basilicum against the cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).  

PubMed

Acaricidal activity of essential oils extracted from cumin seeds (Cuminum cyminum), allspice berries (Pimenta dioica) and basil leaves (Ocimum basilicum) were tested on 10-day-old Rhipicephalus (Boophilus) microplus tick larvae using the LPT. Two-fold dilutions of the three essential oils were tested from a starting dilution of 20% down to 1.25%. Results showed a high toxicological effect for cumin, producing 100% mortality in all tested concentrations on R. microplus larvae. Similarly, allspice essential oil produced 100% mortality at all concentrations with the exception of a dramatic decrease at 1.25% concentration. Conversely, basil essential oil was not shown to be toxic against R. microplus larvae. The most common compounds detected by gas chromatography-mass spectrometry were as follows: cumin: cuminaldehyde (22.03%), ?-terpinene (15.69%) and 2-caren-10-al (12.89%); allspice: methyl eugenol (62.7%) and eugenol (8.3%); basil: linalool (30.61%) and estragole (20.04%). Results clearly indicate that C. cyminum and P. dioica essential oils can be used as an effective alternative for R. microplus tick control, and there is a high probability they can be used for other ticks affecting cattle in Mexico and throughout the world, thereby reducing the necessity for traditional and unfriendly synthetic acaricides. PMID:20865426

Martinez-Velazquez, Moises; Castillo-Herrera, Gustavo Adolfo; Rosario-Cruz, Rodrigo; Flores-Fernandez, Jose Miguel; Lopez-Ramirez, Julisa; Hernandez-Gutierrez, Rodolfo; Lugo-Cervantes, Eugenia del Carmen

2011-02-01

218

Effects of tick control by acaricide self-treatement of white-tailed deer on host-seeking tick infection prevalence and entomologic risk for Ixodes scapularis-borne pathogens  

Technology Transfer Automated Retrieval System (TEKTRAN)

We evaluated the effects of tick control by acaricide self-treatment of white-tailed deer on the infection prevalence and entomologic risk for three I. scapularis-borne bacteria in host-seeking ticks. Ticks were collected from vegetation in areas treated with the ‘4-Poster’ device and from control a...

219

Acaricide treatment prevents adrenocortical hyperplasia as a long-term stress reaction to psoroptic mange in cattle.  

PubMed

In cattle, infestation with Psoroptes ovis mites may cause severe dermatitis (psoroptic mange) which compromises the health and welfare of the animals and may lead to significant economic losses. To investigate yet undocumented effects of psoroptic mange mite infestations and how successful therapy promotes animal health, the present study examined alterations of the skin, lymph nodes and adrenal glands of P. ovis infested Fleckvieh (Simmental) bulls treated with either ivermectin long-acting injection (IVM LAI; IVOMEC(®) GOLD, Merial; 3.15% ivermectin w/v) or saline (n=16 each). Approximately 8 weeks subsequent to experimental infestation with P. ovis, the bulls had developed mange and were administered either IVM LAI or saline once at 1 mL/50 kg body weight by subcutaneous injection. Mite counts were conducted in weekly intervals for determination of efficacy of treatment, and following humane euthanasia of the animals 8 weeks after treatment, skin samples from affected (mangy or previously mangy) and unaffected areas, prescapular lymph nodes and adrenal glands were collected for gross and pathohistological examination. In addition, four age-matching, uninfested Simmental bulls were sampled as controls for comparison. No P. ovis mites were detected on any IVM LAI-treated bull after 28 days following treatment whereas saline-treated bulls maintained infestation throughout the study. At sampling (approximately 16 weeks after experimental infestation and 8 weeks following saline or IVM LAI treatment), saline-treated bulls displayed a severe, exsudative dermatitis with significantly increased skin thickness and inflammatory cell infiltration, significantly enlarged, hyperplastic prescapular lymph nodes, as well as significantly increased adrenal gland weights and volumes as compared to P. ovis-infested, IVM LAI-treated bulls and uninfested controls. Quantitative stereological analysis revealed that the adrenal gland enlargement in P. ovis-infested, saline-treated bulls was due to a selective increase of the volume of the zona fasciculata in the adrenal cortex. Compared to uninfested controls and P. ovis-infested, IVM LAI-treated bulls, the number of epithelial cells in the zona fasciculata was significantly increased in P. ovis-infested, saline-treated bulls, while the zona fasciculata cell volumes did not differ between the three groups of cattle. While the single point determination of serum cortisol concentrations did not reveal significant differences between the three groups of cattle at tissue sampling, the hyperplastic growth of the adrenal cortex in the P. ovis-infested, saline-treated bulls provides morphologic evidence that a chronic stress reaction is one consequence of mange mite infestations that can be prevented by efficacious acaricidal treatment. PMID:25468014

Blutke, A; Börjes, P; Herbach, N; Pfister, K; Hamel, D; Rehbein, S; Wanke, R

2015-01-15

220

Strategic applications of long-acting acaricides against Rhipicephalus (Boophilus) microplus in northwestern Argentina, with an analysis of tick distribution among cattle.  

PubMed

Strategic applications of long-acting acaricides for the control of Rhipicephalus (Boophilus) microplus in northwestern Argentina were evaluated for one year. In addition, tick distribution among cattle was analyzed to evaluate if partial selective treatment or culling the small proportion of most heavily infested animals were feasible options to control R. (B.) microplus. Two different treatments schemes based on two applications of fluazuron and one application of 3.15% ivermectin were performed. Treatments were made in late winter and spring so as to act on the small 1st spring generation of R. (B.) microplus, in order to preclude the rise of the larger autumn generation. The overall treatment effect was positively significant in both schemes. The number of ticks observed in the control group was significantly higher than in the treated groups on all post-treatment counts. Group 2 exhibited more than 80% of efficacy almost throughout the study period, whereas Group 1 exhibited an efficacy percentage higher than 80% in September, October, December, February, April and May, but not in November (73.4%), January (58.3%), March (45.2%) or June (53.4%). Absolute control was observed in Group 2 in the counts of September and October, and in Group 1 in the count of February. The control strategies evaluated in this work provide an acceptable control level with only three applications of acaricides; at the same time, they prevent the occurrence of the autumn peak of tick burdens, which is characteristic of R. (B.) microplus in northwestern Argentina. Tick distribution was markedly aggregated in all counts. Although ticks were not distributed evenly among calves, the individual composition of the most heavily infested group was not consistent throughout the study period. In addition, the level of aggregation varied with tick abundance. These results suggest that applying acaricides to a portion of the herd or culling the most infested individuals at a given moment of the year may not be proper methods to achieve a significant control of R. (B.) microplus in northwestern Argentina. PMID:25670006

Nava, Santiago; Mangold, Atilio J; Canevari, José T; Guglielmone, Alberto A

2015-03-15

221

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

222

Scabies: Who Gets and Causes  

MedlinePLUS

... resources My account Patient education resources Awards, grants, scholarships State society resources Become a member Meetings and ... use criteria MOC Patient safety Awards, grants and scholarships CME transcripts Basic Dermatology Curriculum Choosing Wisely Transplant ...

223

Scabies: Diagnosis, Treatment, and Outcome  

MedlinePLUS

... resources My account Patient education resources Awards, grants, scholarships State society resources Become a member Meetings and ... use criteria MOC Patient safety Awards, grants and scholarships CME transcripts About AAD Recognized Credit Basic Dermatology ...

224

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

225

Chemical characterization and acaricide potential of essential oil from aerial parts of Tagetes patula L. (Asteraceae) against engorged adult females of Rhipicephalus sanguineus (Latreille, 1806).  

PubMed

Rhipicephalus sanguineus, commonly known as the brown dog tick, is one of the most widely distributed species of tick. In dogs, it can cause anemia and provide the transmission of pathogenic microorganisms such as Babesia canis, Ehrlichia canis, Hepatozoon canis, Anaplasma platys, and Mycoplasma haemocanis. To man, it can transmit the intracellular parasites Rickettsia rickettsii and Rickettsia conorii, the causative agents of the Rocky Mountain spotted fever in the Americas and Mediterranean and spotted fever in Europe and North Africa. Its control is performed by applying synthetic formulations composed of pyrethroids; however, continued use of these products results in environmental damage and acquisition of resistance. Alternatively, studies with botanical insecticides have been increasingly recurrent. Therefore, this study aimed to test the efficacy of essential oil of Tagetes patula, a ruderal species widely described in the literature for its insecticidal properties, in engorged females of R. sanguineus by the adults immersion test (AIT) and impregnated paper disk test (IPDT). The essential oil used, through gas chromatography coupled to mass spectrometry, revealed the presence of 55 compounds, being the 4-vinyl guaiacol and gamma terpinene the majority ones. The AIT compared to the IPDT was more efficient in inhibiting oviposition of tick; however, the eggs laid by the females submitted to saturated atmosphere with essential oil, from IPDT, not hatched, interrupted their development cycle. Besides being a pioneer work, the results presented here contributes to new researches, aiming the incorporation of essential oil in an acaricide for use in the environment. PMID:23508761

Politi, Flávio Augusto Sanches; de Souza-Moreira, Tatiana Maria; Rodrigues, Edvânio Ramos; de Queiroz, Geisiany Maria; Figueira, Glyn Mara; Januário, Ana Helena; Berenger, Jean-Michel; Socolovschi, Cristina; Parola, Philippe; Pietro, Rosemeire Cristina Linhari Rodrigues

2013-06-01

226

New method using quantitative PCR to follow the tick blood meal and to assess the anti-feeding effect of topical acaricide against Rhipicephalus sanguineus on dogs.  

PubMed

A 28-day study was conducted to assess the dynamic of blood feeding by Rhipicephalus sanguineus ticks on dogs treated or not with a novel topical combination of fipronil, amitraz and (S)-methoprene. Dogs were infested weekly through exposure to ticks in crates for 4h. Ticks were then counted in the crates at 2h and 4h post dog exposure. Ticks were also counted and removed from the dogs at 2h, 4h, 6h, 12h and 24h post tick exposure. The inhibition of blood feeding was assessed by both tick quantification and designing and performing a quantitative PCR (qPCR) to detect the canine hydroxymethylbilane synthase (HMBS) gene in ticks. The percentage of repellency sensu lato based on the ticks collected in crates at 2h varied from 4.7% at day 28 to 48.3% at day 7. The immediate mortality rate of the ticks expelled at 2h varied from 1.5% at day 21 to 31.7% at day 7. The efficacy calculation showed that the acaricidal combination started to kill ticks in as little as 2h. The average efficacy reached 90.0% at 12h post crate challenges and 100% at 24h post exposure in crates. The inclusion of an internal amplification control was used to ensure that no significant template-derived PCR inhibition (? 6.2%) affected the overall results. The reduction of blood feeding was significant at 4h (>80.0%) and >99.0% at 24h post tick exposure in the crate. The high repellency rate and the lethal efficacy of CERTIFECT(®) resulted in significantly fewer live attached ticks, consequently reducing blood intake and fluid exchanges. PMID:24656063

Fourie, J J; Joubert, A; Labuschagné, M; Beugnet, F

2014-05-01

227

The novel isoxazoline ectoparasiticide fluralaner: selective inhibition of arthropod ?-aminobutyric acid- and L-glutamate-gated chloride channels and insecticidal/acaricidal activity.  

PubMed

Isoxazolines are a novel class of parasiticides that are potent inhibitors of ?-aminobutyric acid (GABA)-gated chloride channels (GABACls) and L-glutamate-gated chloride channels (GluCls). In this study, the effects of the isoxazoline drug fluralaner on insect and acarid GABACl (RDL) and GluCl and its parasiticidal potency were investigated. We report the identification and cDNA cloning of Rhipicephalus (R.) microplus RDL and GluCl genes, and their functional expression in Xenopus laevis oocytes. The generation of six clonal HEK293 cell lines expressing Rhipicephalus microplus RDL and GluCl, Ctenocephalides felis RDL-A285 and RDL-S285, as well as Drosophila melanogaster RDLCl-A302 and RDL-S302, combined with the development of a membrane potential fluorescence dye assay allowed the comparison of ion channel inhibition by fluralaner with that of established insecticides addressing RDL and GluCl as targets. In these assays fluralaner was several orders of magnitude more potent than picrotoxinin and dieldrin, and performed 5-236 fold better than fipronil on the arthropod RDLs, while a rat GABACl remained unaffected. Comparative studies showed that R. microplus RDL is 52-fold more sensitive than R. microplus GluCl to fluralaner inhibition, confirming that the GABA-gated chloride channel is the primary target of this new parasiticide. In agreement with the superior RDL on-target activity, fluralaner outperformed dieldrin and fipronil in insecticidal screens on cat fleas (Ctenocephalides felis), yellow fever mosquito larvae (Aedes aegypti) and sheep blowfly larvae (Lucilia cuprina), as well as in acaricidal screens on cattle tick (R. microplus) adult females, brown dog tick (Rhipicephalus sanguineus) adult females and Ornithodoros moubata nymphs. These findings highlight the potential of fluralaner as a novel ectoparasiticide. PMID:24365472

Gassel, Michael; Wolf, Christian; Noack, Sandra; Williams, Heike; Ilg, Thomas

2014-02-01

228

[Drug Exposed Infants and Their Families.  

ERIC Educational Resources Information Center

This bulletin issue addresses the theme of drug-exposed infants and the services required by these infants and their families. "Cocaine-Exposed Infants: Myths and Misunderstandings" (Barbara J. Myers and others) comments on the negative accounts of drug-exposed babies presented by mass media and reviews the mix of positive and negative findings…

Fenichel, Emily, Ed.

1992-01-01

229

The lead-exposed worker  

SciTech Connect

The lead standard established by the federal Occupational Safety and Health Administration in 1978 requires physicians and employers to follow very specific guidelines when treating lead-exposed workers. For example, if a worker's blood lead level is 2.90 {mu}mol/L of whole blood or greater, the worker must be removed from work, with full pay and retention of seniority, until the blood level falls below 1.95 {mu}mol/L. Physicians play a key role in the implementation of the lead standard; the standard specifies frequency of blood lead measurements, frequency and extent of medical monitoring, and medical removal from work. This article reviews the lead standard as it applies to physicians and makes recommendations about managing the worker with lead poisoning.

Rempel, D. (California Department of Health Services, Berkeley (USA))

1989-07-28

230

Insecticidal, acaricidal and repellent effects of DEET- and IR3535-impregnated bed nets using a novel long-lasting polymer-coating technique.  

PubMed

A novel long-lasting repellent-treated net (LLRTN) has been designed by binding the skin repellents N,N-diethyl-m-toluamide (DEET), or IR3535, onto the fibres of bed net fabric using a new polymer-coating technique. The repellent toxicological effectiveness and residual activity of a factory-based repellent-impregnated fabric has been evaluated by laboratory testing against adult Aedes aegypti mosquitoes and nymphal Ixodes ricinus ticks. By using this repellent-embedding impregnation technique, concentrations exceeding 10 g/m(2) could be achieved with one single polymer layer. Both DEET- and IR3535-impregnated fabrics revealed a dose-dependent insecticidal as well as acaricidal activity. One hundred percent knockdown times of DEET-treated bed nets ranged from 187.5 +/- 31.8 to 27.5 +/- 3.5 min against A. aegypti, and between 214 +/- 47 and 22.6 +/- 5 min against nymphal I. ricinus, linked to a DEET concentration of 1.08 and 10.58 g/m(2), respectively. With IR3535, A. aegypti produced dose-dependent 100% knockdown times varying from 87.5 +/- 10.6 to 57.5 +/- 3.5 min and between 131.4 +/- 6.5 and 33.8 +/- 5 min against nymphal I. ricinus, respectively, linked to concentrations between 1.59 and 10.02 g/m(2). One hundred percent repellency measured by complete landing and biting protection of impregnated fabric by using the arm-in-cage test could be achieved at DEET concentrations exceeding 3.7 to 3.9 g/m(2), and for IR3535 concentrations over 10 g/m(2). One hundred percent landing and biting protection could be preserved with DEET-treated fabrics for 29 weeks at an initial concentration of 4.66 g/m(2), 54 weeks at 8.8 g/m(2), 58 weeks at 9.96 g/m(2) and 61 weeks at 10.48 g/m(2) for DEET, and 23 weeks for IR3535-treated fabric at a concentration of 10.02 g/m(2). Unlike repellent-treated fabric, a brand of a commercially available long-lasting insecticide-treated net tested containing 500 mg permethrin/m(2) did not protect from mosquito bites. First results on bioactivity and long-lasting efficacy show that the new LLRTN technique is highly promising as a potential candidate for future malaria control strategies, especially in areas where pyrethroid resistance occurs. PMID:20162432

Faulde, Michael K; Albiez, Gunther; Nehring, Oliver

2010-03-01

231

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

232

Interphase Cytogenetics of Workers Exposed to Benzene  

E-print Network

Interphase Cytogenetics of Workers Exposed to Benzene Luoping Zhang,1 Nathaniel Rothman,2 Yunxia has been used to demonstrate that the benzene metabolites hydroquinone and 1,2,4-benzenetriol induce FISH procedure to perform cytogenetic analyses on the blood cells of 43 workers exposed to benzene

California at Berkeley, University of

233

Orbital debris as detected on exposed spacecraft  

Microsoft Academic Search

Spacecraft surfaces returned to the laboratory after being exposed to the low Earth orbit (LEO) environment have been examined by Scanning Electron Microscopy and Energy Dispersive X-ray (SEM\\/EDX) over the last two decades. Although many of these surfaces were not intended to be used as hypervelocity impact capture medium, meteoroid and orbital debris particles colliding with exposed surfaces are well

R. P. Bernhard; E. L. Christiansen; D. E. Kessler

1997-01-01

234

Eryptosis in lead-exposed workers.  

PubMed

Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8?g/dl) and non-exposed workers (4.2?g/dl). The exposure to lead produced an intoxication characterized by 88.3% less ?-aminolevulinic acid dehydratase (?ALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca(2+)]i and 1.6 times higher ?-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (<0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca(2+)], ?-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. PMID:25448684

Aguilar-Dorado, Itzel-Citlalli; Hernández, Gerardo; Quintanar-Escorza, Martha-Angelica; Maldonado-Vega, María; Rosas-Flores, Margarita; Calderón-Salinas, José-Víctor

2014-12-01

235

3 EXPOSE Missions - overview and lessons learned  

NASA Astrophysics Data System (ADS)

The International Space Station ISS provides a variety of external research platforms for experiments aiming at the utilization of space parameters like vacuum, temperature oscillation and in particular extraterrestrial short wavelength UV and ionizing radiation which cannot be simulated accurately in the laboratory. Three Missions, two past and one upcoming, will be presented. A family of astrobiological experimental ESA facilities called "EXPOSE" were and will be accommodated on these outside exposure platforms: on one of the external balconies of the European Columbus Module (EXPOSE-E) and on the URM-D platform on the Russian Zvezda Module (EXPOSE-R and EXPOSE-R2). Exobiological and radiation experiments, exposing chemical, biological and dosimetric samples to the harsh space environment are - and will be - accommodated on these facilities to increase our knowledge on the origin, evolution and distribution of life, on Earth and possibly beyond. The biological experiments investigate resistance and adaptation of organisms like bacteria, Achaea, fungi, lichens, plant seeds and small animals like mosquito larvae to extreme environmental conditions and underlying mechanisms like DNA repair. The organic chemical experiments analyse chemical reactions triggered by the extraterrestrial environment, especially short wavelength UV radiation, to better understand prebiotic chemistry. The facility is optimized to allow exposure of biological specimen and material samples under a variety of conditions, using optical filter systems. Environmental parameters like temperature and radiation are regularly recorded and down linked by telemetry. Two long term missions named according to their facility - EXPOSE-E and EXPOSE-R - are completed and a third mission is planned and currently prepared. Operations of all three missions including sample accommodation are performed by DLR. An overview of the two completed missions will be given including lessons learned as well as an outlook and short introduction to the next mission, EXPSOE-R2

Rabbow, E.; Willnekcer, R.; Reitz, G.; Aman, A.; Bman, B.; Cman, C.

2011-10-01

236

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...

237

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...

238

Helping Children Exposed to Domestic Violence  

MedlinePLUS

... withdrawal Depression or anxiety Loss of interest in school, friends or other things they enjoyed in the past Children and adolescents exposed to domestic violence should be evaluated by a trained mental health ...

239

Disposal of tritium-exposed metal hydrides  

SciTech Connect

A plan has been established for disposal of tritium-exposed metal hydrides used in Savannah River Site (SRS) tritium production or Materials Test Facility (MTF) R D operations. The recommended plan assumes that the first tritium-exposed metal hydrides will be disposed of after startup of the Solid Waste Disposal Facility (SWDF) Expansion Project in 1992, and thus the plan is consistent with the new disposal requiremkents that will be in effect for the SWDF Expansion Project. Process beds containing tritium-exposed metal hydride powder will be disposed of without removal of the powder from the bed; however, disposal of tritium-exposed metal hydride powder that has been removed from its process vessel is also addressed.

Nobile, A.; Motyka, T.

1991-01-01

240

Disposal of tritium-exposed metal hydrides  

SciTech Connect

A plan has been established for disposal of tritium-exposed metal hydrides used in Savannah River Site (SRS) tritium production or Materials Test Facility (MTF) R&D operations. The recommended plan assumes that the first tritium-exposed metal hydrides will be disposed of after startup of the Solid Waste Disposal Facility (SWDF) Expansion Project in 1992, and thus the plan is consistent with the new disposal requiremkents that will be in effect for the SWDF Expansion Project. Process beds containing tritium-exposed metal hydride powder will be disposed of without removal of the powder from the bed; however, disposal of tritium-exposed metal hydride powder that has been removed from its process vessel is also addressed.

Nobile, A.; Motyka, T.

1991-12-31

241

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

242

Anesthetic gases and occupationally exposed workers.  

PubMed

The aim of this study is to estimate whether the occupational exposure to low dose anesthetic gases could cause alterations of blood parameters in health care workers. 119 exposed subjects and 184 not exposed controls were included in the study. Each worker underwent the complete blood count test (CBC), proteinaemia, leukocyte count, serum lipids, liver and kidney blood markers. The liver blood markers show statistically significant differences in health care workers compared with controls (p<0.05), a statistically significant decrease in neutrophils and an increase of lymphocytes in health care workers compared with controls (p<0.05). The prevalence of values outside the range for GPT, GGT, total bilirubin, lymphocytes and neutrophils was statistically significant in health care workers compared with controls (p<0.05). The results suggest that occupational exposure to low dose anesthetic gases could influence some haematochemical hepatic and hematopoietic parameters in exposed health care workers. PMID:24374387

Casale, Teodorico; Caciari, Tiziana; Rosati, Maria Valeria; Gioffrè, Pier Agostino; Schifano, Maria Pia; Capozzella, Assunta; Pimpinella, Benedetta; Tomei, Gianfranco; Tomei, Francesco

2014-01-01

243

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

244

Cosmic radiation exposure of biological test systems during the EXPOSE-R mission  

NASA Astrophysics Data System (ADS)

In the frame of the EXPOSE-R mission outside the Russian Zvezda Module of the International Space Station (ISS) passive thermoluminescence dosimeters were applied to measure the radiation exposure of biological samples. The detectors were located beneath the sample carriers to determine the dose levels for maximum shielding. The dose measured beneath the sample carriers varied between 317 +/- 10 and 230 +/- 2 mGy, which amount to an average dose rate of 381 +/- 12 and 276 +/- 2 ?Gy d-1. These values are close to those assessed for the interior of the ISS and reflect the high shielding of the biological experiments within the EXPOSE-R facility. As a consequence of the high shielding (several g cm-2), the biological samples were predominantly exposed to galactic cosmic heavy ions and trapped protons in the Earth's radiation belts, whereas the trapped electrons did not reach the samples.

Berger, Thomas; Hajek, Michael; Bilski, Pawel

2015-01-01

245

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

246

DSC of sun-exposed chloroquine phosphate  

Microsoft Academic Search

Pharmaceutical intended for use in the tropics are required to maintain their stability under the most severe storage conditions. Chloroquine phosphate, a common antimalarial formulation, was exposed to the sun of the roof top under the extreme heat of the Saharan climate during the hot and dry season (February to June) at an average day temperature of 43°. The heat

G. Mulokozi; I. Edafiogho; A. M. Mulokozi; S. Diete-Spiff

1987-01-01

247

Cocaine Babies: Florida's Substance-Exposed Youth.  

ERIC Educational Resources Information Center

This report is designed to provide Florida's school personnel with assistance in working with students prenatally exposed to cocaine or other toxic substances. The report offers background data, practical strategies for teaching and learning, and resources for networking. The first chapter outlines statistics on the incidence of the problem of…

Harpring, Jayme

248

Exposing the Mathematical Wizard: Approximating Trigonometric Functions  

ERIC Educational Resources Information Center

For almost all students, what happens when they push buttons on their calculators is essentially magic, and the techniques used are seemingly pure wizardry. In this article, the author draws back the curtain to expose some of the mathematics behind computational wizardry and introduces some fundamental ideas that are accessible to precalculus…

Gordon, Sheldon P.

2011-01-01

249

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

250

Expose Mechanical Engineering Students to Biomechanics Topics  

ERIC Educational Resources Information Center

To adapt the focus of engineering education to emerging new industries and technologies nationwide and in the local area, a biomechanics module has been developed and incorporated into a mechanical engineering technical elective course to expose mechanical engineering students at ONU (Ohio Northern University) to the biomedical engineering topics.…

Shen, Hui

2011-01-01

251

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...

252

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

253

Lung function in workers exposed to polyvinyl chloride dust  

Microsoft Academic Search

Several reported studies on the effects of polyvinyl chloride (PVC) dust in animals and man have been conflicting. The present study of the ventilatory function of 509 male workers exposed to PVC dust was made in 1977. Altogether 104 men exposed to PVC dust only, 112 men exposed to non-chlorinated solvents only, and 293 men exposed to a mixture of

C P Chivers; C Lawrence-Jones; G M Paddle

1980-01-01

254

NEONATAL VISUAL INFORMATION PROCESSING IN COCAINE-EXPOSED AND NON-EXPOSED INFANTS  

PubMed Central

This study investigated early neonatal visual preferences in 267 poly drug exposed neonates (131 cocaine-exposed and 136 non-cocaine exposed) whose drug exposure was documented through interviews and urine and meconium drug screens. Infants were given four visual recognition memory tasks comparing looking time to familiarized stimuli of lattices and rectangular shapes to novel stimuli of a schematic face and curved hourglass and bull’s eye forms. Cocaine-exposed infants performed more poorly, after consideration of confounding factors, with a relationship of severity of cocaine exposure to lower novelty score found for both self-report and biologic measures of exposure, Findings support theories which link prenatal cocaine exposure to deficits in information processing entailing attentional and arousal organizational systems. Neonatal visual discrimination and attention tasks should be further explored as potentially sensitive behavioral indicators of teratologic effects. PMID:25717215

Singer, Lynn T.; Arendt, Robert; Fagan, Joseph; Minnes, Sonia; Salvator, Ann; Bolek, Tina; Becker, Michael

2014-01-01

255

Work ability in vibration-exposed workers  

PubMed Central

Background Hand–arm vibration exposure may cause hand–arm vibration syndrome (HAVS) including sensorineural disturbances. Aims To investigate which factors had the strongest impact on work ability in vibration-exposed workers. Methods A cross-sectional study in which vibration-exposed workers referred to a department of occupational and environmental medicine were compared with a randomized sample of unexposed subjects from the general population of the city of Gothenburg. All participants underwent a structured interview, answered several questionnaires and had a physical examination including measurements of hand and finger muscle strength and vibrotactile and thermal perception thresholds. Results The vibration-exposed group (47 subjects) showed significantly reduced sensitivity to cold and warmth in digit 2 bilaterally (P < 0.01) and in digit 5 in the left hand (P < 0.05) and to warmth in digit 5 in the right hand (P < 0.01), compared with the 18 referents. Similarly, tactilometry showed significantly raised vibration perception thresholds among the workers (P < 0.05). A strong relationship was found for the following multiple regression model: estimated work ability = 11.4 ? 0.1 × age ? 2.3 × current stress level ? 2.5 × current pain in hands/arms (multiple r = 0.68; P < 0.001). Conclusions Vibration-exposed workers showed raised vibrotactile and thermal perception thresholds, compared with unexposed referents. Multiple regression analysis indicated that stress disorders and muscle pain in hands/arms must also be considered when evaluating work ability among subjects with HAVS. PMID:25145484

Hagberg, M.

2014-01-01

256

Prosocial coping by youth exposed to violence  

Microsoft Academic Search

Chronic exposure to violence encourages youth to cope with challenges via a mixture of asocial, depressive and antisocial,\\u000a aggressive tactics rather than prosocially in ways that benefit self without harming others. Youth exposed to violence are,\\u000a therefore, not only at high risk for posttraumatic stress disorder (PTSD) but also for externalizing and internalizing behavior\\u000a problems, school dropout, teen pregnancy, substance

Elaine A. Blechman; Jean E. Dumas; Ronald J. Prinz

1994-01-01

257

Aphid acceptance of barley exposed to volatile phytochemicals differs between plants exposed in daylight and darkness.  

PubMed

It is well known that volatile cues from damaged plants may induce resistance in neighboring plants. Much less is known about the effects of volatile interaction between undamaged plants. In this study, barley plants, Hordeum vulgare cv. Kara, were exposed to volatiles from undamaged plants of barley cv. Alva or thistle Cirsium vulgare, and to the volatile phytochemicals, methyl salicylate or methyl jasmonate. Exposures were made either during natural daylight or darkness. Acceptance of exposed plants by the aphid Rhopalosiphum padi was assessed, as well as the expression of putative marker genes for the different treatments. Aphid acceptance of plants exposed to either barley or C. vulgare was significantly reduced, and an effect of the volatiles from undamaged plants was confirmed by the induction of pathogenesis-related protein, PR1a in exposed plants. However the effect on aphid acceptance was seen only when plants were exposed during darkness, whereas PR1a was induced only after treatment during daylight. Aphid acceptance of plants exposed to either methyl salicylate or methyl jasmonate was significantly reduced, but only when plants were exposed to the chemicals during daylight. AOS2 (allene oxide synthase) was induced by methyl jasmonate and BCI-4 (barley chemical inducible gene-4) by methyl salicylate in both daylight and darkness. It is concluded that (a) the effects on aphids of exposing barley to volatile phytochemicals was influenced by the presence or absence of light and (b) the response of barley to methyl salicylate/methyl jasmonate and to volatiles from undamaged plants differed at the gene and herbivore level. PMID:19516995

Glinwood, Robert; Gradin, Therese; Karpinska, Barbara; Ahmed, Elham; Jonsson, Llisbeth; Ninkovic, Velemir

2007-09-01

258

Aphid Acceptance of Barley Exposed to Volatile Phytochemicals Differs Between Plants Exposed in Daylight and Darkness  

PubMed Central

It is well known that volatile cues from damaged plants may induce resistance in neighboring plants. Much less is known about the effects of volatile interaction between undamaged plants. In this study, barley plants, Hordeum vulgare cv. Kara, were exposed to volatiles from undamaged plants of barley cv. Alva or thistle Cirsium vulgare, and to the volatile phytochemicals, methyl salicylate or methyl jasmonate. Exposures were made either during natural daylight or darkness. Acceptance of exposed plants by the aphid Rhopalosiphum padi was assessed, as well as the expression of putative marker genes for the different treatments. Aphid acceptance of plants exposed to either barley or C. vulgare was significantly reduced, and an effect of the volatiles from undamaged plants was confirmed by the induction of pathogenesis-related protein, PR1a in exposed plants. However the effect on aphid acceptance was seen only when plants were exposed during darkness, whereas PR1a was induced only after treatment during daylight. Aphid acceptance of plants exposed to either methyl salicylate or methyl jasmonate was significantly reduced, but only when plants were exposed to the chemicals during daylight. AOS2 (allene oxide synthase) was induced by methyl jasmonate and BCI-4 (barley chemical inducible gene-4) by methyl salicylate in both daylight and darkness. It is concluded that (a) the effects on aphids of exposing barley to volatile phytochemicals was influenced by the presence or absence of light and (b) the response of barley to methyl salicylate/methyl jasmonate and to volatiles from undamaged plants differed at the gene and herbivore level. PMID:19516995

Glinwood, Robert; Gradin, Therese; Karpinska, Barbara; Ahmed, Elham; Jonsson, Llisbeth

2007-01-01

259

Rescue of fish exposed to a lethal dose of pathogen, by signals from sublethally exposed survivors.  

PubMed

Rainbow trout (Oncorhynchus mykiss, Walbaum) were challenged intraperitoneally with a sublethal dose of Vibrio anguillarum VIB1 and allowed to recover. Then, after 7 days, naïve fish, (designated as 'bystander' fish) which had never been exposed to the pathogen, were introduced to the same tank. These swam with the adapted (recovered) fish for 7 days before both groups and a control (never exposed directly to the pathogen or to recovered fish) group were exposed to a lethal dose of VIB1. Mortality records were 100% in the control group within 3 days, 47% in the adapted group and 60% in the unchallenged bystander group, which swam with the adapted group. In both the latter groups, the time to death of the non-surviving fish was attenuated. This inter-animal communication of signals has previously been documented for animals exposed to ionizing radiation. Assays of tissues from control, challenged and 'bystander fish exposed to the pathogen showed that a signal as yet unidentified but similar to that seen in bystanders to irradiated fish was being produced. This signal caused a sharp and transient increase in intracellular calcium and a decrease in clonogenicity in a well-characterized reporter assay. PMID:25757731

Mothersill, Carmel; Austin, Dawn; Fernandez-Palomo, Cristian; Seymour, Colin; Auchinachie, Niall; Austin, Brian

2015-03-01

260

The PUR Experiment on the EXPOSE-R facility: biological dosimetry of solar extraterrestrial UV radiation  

NASA Astrophysics Data System (ADS)

The aim of our experiment Phage and Uracil Response was to extend the use of bacteriophage T7 and uracil biological dosimeters for measuring the biologically effective ultraviolet (UV) dose in the harsh extraterrestrial radiation conditions. The biological detectors were exposed in vacuum-tightly cases in the European Space Agency (ESA) astrobiological exposure facility attached to the external platform of Zvezda (EXPOSE-R). EXPOSE-R took off to the International Space Station (ISS) in November 2008 and was installed on the External platform of the Russian module Zvezda of the ISS in March 2009. Our goal was to determine the dose-effect relation for the formation of photoproducts (i.e. damage to phage DNA and uracil, respectively). The extraterrestrial solar UV radiation ranges over the whole spectrum from vacuum-UV (?<200 nm) to UVA (315 nm

Bérces, A.; Egyeki, M.; Fekete, A.; Horneck, G.; Kovács, G.; Panitz, C.

2015-01-01

261

Erythrocyte survival in sheep exposed to ozone  

SciTech Connect

Erythrocyte survival studies in the Dorset ewe using chromium 51 were performed. The purpose of the study was to determine if ozone exposure produces decreased cell survival which may be the result of premature erythrocyte aging. This strain of sheep has an erythrocyte glucose-6-phosphate dehydrogenase (G6PD) activity that is very low, being comparable to human A-variants with G6PD deficiency. Ozone exposure may produce hemolytic effects in G6PD deficients more readily than in erythrocytes with normal activity. A decrease in hematocrit was observed in the ozone exposed groups. With respect to red cell destruction, ozone does not appear to act immediately, but rather there appears to be a delayed effect. At 0.25 ppM ozone, the group reached the 50% remaining level an average of 1 day sooner than the control group. There was no significant difference between control and exposed groups at the 0.50 ppM and 0.70 ppM levels. Also, the results demonstrate a net decrease in hematocrit which is greater for 0.25 ppM ozone than any other exposure level. (RJC)

Moore, G.S.; Calabrese, E.J.; Labato, F.J.

1981-07-01

262

The ORGANIC Experiment on EXPOSE-R on the ISS: A Space Exposure Experiment  

NASA Astrophysics Data System (ADS)

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 on the multi-user facility EXPOSE-R onboard the ISS. The ORGANIC experiment monitored the chemical evolution, survival, destruction, and chemical modification of the samples. EXPOSE-R was mounted on the outside of the ISS from March 10, 2009 to January 21, 2011. The samples were returned to Earth and inspected in spring 2011. The 682-day 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 spectroscopy. Ground truth monitoring of additional sample carriers was performed through UV-VIS spectroscopy at regular intervals at NASA Ames Research Center. During the exposure on the ISS, 2 control sample carriers were exposed with a slight time shift in a planetary simulation chamber at the Microgravity User Support Center at DLR. Vacuum, UV radiation, and temperature fluctuations are simulated according to the telemetry data measured during flight. The spectroscopic measurements of these two carriers have been performed together with the returned flight samples. We report on the scientific experiment, the details of the ground control analysis, and preliminary flight sample results.

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

2013-06-01

263

7 CFR 27.33 - Exposing of samples for classification.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Exposing of samples for classification. 27...COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSIFICATION...Determinations § 27.33 Exposing of samples for classification. Classification...shall not proceed until the samples, after being...

2010-01-01

264

7 CFR 28.37 - Exposing of samples for classification.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Exposing of samples for classification. 28...COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING...Classification § 28.37 Exposing of samples for classification. Classification...shall not proceed until the samples, after being...

2010-01-01

265

An incidence survey of fibromyalgia in mold exposed patients  

Microsoft Academic Search

An incidence survey of fibromyalgia (FM) was done on mold exposed patients at Progressive Healthcare Group, Benson, AZ. Through a medical records audit, percentages of FM diagnosis were calculated for patients who had been exposed to toxigenic structural molds, those who had been exposed to chemicals, and those in the regular internal medicine practice population. Of those with mold exposure,

Jessica A Zagory; Michael R Gray

266

Acaricidal effect of a diatomaceous earth formulation against Tyrophagus putrescentiae (Astigmata: Acaridae) and its predator Cheyletus malaccensis (Prostigmata: Cheyletidae) in four grain commodities.  

PubMed

Laboratory bioassays were conducted to evaluate the effect of the diatomaceous earth (DE) formulation SilicoSec (Biofa GmbH, Münsingen, Germany), against two stored-product mite species, Tyrophagus putrescentiae (Shrank) and the predator Cheyletus malaccensis Oudemans. For this purpose, DE was applied in wheat, oat, rye, and maize, at the dose rates 0, 0.5, 1, and 2 g/kg grain. The mortality of the exposed mites was assessed after 24 h, 48 h, 7 d, and 14 d of exposure in the treated substrate. After this interval, the treated grains were checked for oviposition or progeny. The tests were conducted at 80% RH and at two temperatures, 20 and 25 degrees C. Generally, for both species, mortality was higher at 25 degrees C than at 20 degrees C. For T. putrescentiae, at both temperatures, the mortality in grains treated with the highest DE rate was 100% after only 24 h of exposure, with the exception of maize at 20 degrees C, where mortality was 91.7%. The mortality of C. malaccensis after 24 h of exposure to the treated grains, in the absence of prey, did not exceed 29% at any of the temperature- grain-dose combinations, whereas no mites were dead in rye and maize treated with 0.5 and 1 g of DE. Even after 14 d of exposure at the highest DE rate, mite mortality did not reach 100%. The presence of T. putrescentiae individuals as prey in the treated substrate enhanced C. malaccensis survival. Hence, after 14 d of exposure, the mortality of C. malaccensis, in wheat, oat, rye, and maize treated with the highest DE rate was 51.7, 59.7, 70, and 36.9, respectively. No progeny production was recorded in the treated substrate for T. putrescentiae; in contrast, oviposition and F1 progeny were recorded for C. malaccensis. Our results suggest that the use of C. malaccensis with low doses of DE may be an appealing integrated pest management (IPM) approach against T. putrescentiae, and probably against other stored-grain mite species. PMID:16573344

Palyvos, Nickolas E; Athanassiou, Christos G; Kavallieratos, Nickolas G

2006-02-01

267

First results of the ORGANIC experiment on EXPOSE-R on the ISS  

NASA Astrophysics Data System (ADS)

The ORGANIC experiment on EXPOSE-R spent 682 days outside the International Space Station, providing continuous exposure to the cosmic-, solar- and trapped-particle radiation background for fourteen samples: 11 polycyclic aromatic hydrocarbons (PAHs) and three fullerenes. The thin films of the ORGANIC experiment received, during space exposure, an irradiation dose of the order of 14 000 MJ m-2 over 2900 h of unshadowed solar illumination. Extensive analyses were performed on the returned samples and the results compared to ground control measurements. Analytical studies of the returned samples included spectral measurements from the vacuum ultraviolet to the infrared range and time-of-flight secondary ion mass spectrometry. Limited spectral changes were observed in most cases pointing to the stability of PAHs and fullerenes under space exposure conditions. Furthermore, the results of these experiments confirm the known trend in the stability of PAH species according to molecular structure: compact PAHs are more stable than non-compact PAHs, which are themselves more stable than PAHs containing heteroatoms, the last category being the most prone to degradation in the space environment. We estimate a depletion rate of the order of 85 +/- 5% over the 17 equivalent weeks of continuous unshadowed solar exposure in the most extreme case tetracene (smallest, non-compact PAH sample). The insignificant spectral changes (below 10%) measured for solid films of large or compact PAHs and fullerenes indicate a high stability under the range of space exposure conditions investigated on EXPOSE-R.

Bryson, K. L.; Salama, F.; Elsaesser, A.; Peeters, Z.; Ricco, A. J.; Foing, B. H.

2015-01-01

268

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

269

Exposed polyurethane seen as fire hazard  

SciTech Connect

Improperly exposed polyurethane insulation is a fire hazard. Recent fire tragedies underscore the importance of installing approved thermal barriers over the foam. Vendors warn of the need to follow building codes and manufacturer's guidelines, and stress the absence of hazards if this is done. Polyurethane foam requires a high temperature to ignite but, once ignited, flashes intensely. The foam smolders at lower temperatures, however, and gives off combustible gases. The risk is higher in warehouses and other buildings where the foam is often sprayed on the walls and left uncovered and in upholstered furniture. Lawsuits resulted over claims that the material is self-extinguishing. Vendors list commercially available thermal barriers and factors customers should consider before investing in foam. (DCK)

Weaver, M.

1982-11-29

270

Plasma prolactin concentrations in lead exposed workers.  

PubMed

Plasma Prolactin (Prl) Zinc protoporphyrin (Zpp) and blood lead concentrations (PbB) were measured in 76 exposed male workers. All of them were employed in small (not more than 30 persons) pewter factories and were randomly selected from those regularly controlled by the National Health Service, Occupational Health Unit of Brescia (USSL 41). Although all plasma Prl values were within the normal range, the mean value of the subgroup having Zpp and PbB higher than 40 micrograms/dl was significantly higher (+47%) than that observed in the group of workers having Zpp and PbB less than 40 micrograms/dl. The data indicate the possibility of a lead-induced Prl secretion dysfunction, probably mediated by a decrease in dopaminergic inhibitory control. PMID:3598878

Govoni, S; Battaini, F; Fernicola, C; Castelletti, L; Trabucchi, M

1987-01-01

271

Mortality among industrial workers exposed to formaldehyde  

SciTech Connect

A historical cohort study evaluated the mortality experience of 26,561 workers employed in 10 formaldehyde-producing or -using facilities. Approximately 600,000 person-years of follow-up accrued as workers were followed to January 1, 1980. Estimates of historical exposure to formaldehyde by job were developed by project industrial hygienists using monitoring data available from participating plants, comments from long-term workers, and comprehensive monitoring data specifically collected for this study. Mortality from all causes combined was about as expected (standardized mortality ratio (SMR) = 96) based on mortality rates of the general U.S. population. Significantly fewer deaths occurred from infective and parasitic diseases (SMR = 51) and from accidents (SMR = 72) than expected. Cancer overall was not related to formaldehyde exposure. Workers exposed to formaldehyde had slight excesses for Hodgkin's disease and cancers of the lung and prostate gland, but these excesses were not consistently related to duration of or average, cumulative, or peak formaldehyde exposure levels. Recent animal studies found nasal cancer among rats exposed to formaldehyde, but no excess of this tumor occurred in this study. Mortality from brain cancer and leukemia among these industrial workers was not excessive in contrast to reported excesses among professional groups (e.g., anatomists, embalmers, and pathologists) with exposure to formaldehyde. Although there was a deficit for cancer of the buccal cavity and pharynx, mortality from certain subsites, i.e., the nasopharynx and oropharynx, was elevated. These subsites did not, however, show a consistently rising risk with level of exposure. These data provide little evidence that mortality from cancer is associated with formaldehyde exposure at levels experienced by workers in this study.

Blair, A.; Stewart, P.; O'Berg, M.; Gaffey, W.; Walrath, J.; Ward, J.; Bales, R.; Kaplan, S.; Cubit, D.

1986-06-01

272

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

273

In vitro and in vivo acaricide action of juvenoid analogs produced from the chemical modification of Cymbopogon spp. and Corymbia citriodora essential oil on the cattle tick Rhipicephalus (Boophilus) microplus.  

PubMed

The present study aimed to evaluate the acaricidal action of the chemically modified essential oil of Cymbopogon spp. and Corymbia citriodora on Rhipicephalus (Boophilus) microplus. Citronellal was converted into N-butylcitronellylamine and in N-prop-2-inylcitronellylamine, analogs of juvenoids, by reductive amination using butylamine (N1 to N3) and propargylamine (N4 to N7). In vitro assays included the adult immersion, and larval packet tests. Engorged females were weighed in groups of 10 and tested in three replicates for six concentrations. They were immersed in the modified oils or control solution and incubated. In the larval packet test, the same substances and concentrations were evaluated in three replicates. In the in vivo test, six pastured heifers naturally infested with R. (B.) microplus were used per treatment: negative control, positive control (amitraz, Triatox(®)), original oil of C. citriodora at 1.5%, and modified oil containing 0.9% N-prop-2-inylcitronellylamine (N7). Ticks were counted in the right side of the body in 24 animals from day D-3 to D21. LC50 and LC90 were obtained by Probit analysis, while the in vivo results were log transformed and compared using the Tukey test. Among the nitrocellylamines tested in vitro, N6 was most effective on the engorged females (100% efficacy at 50mg/mL) and N7 on the larvae (100% efficacy at 6.25mg/mL). In the test with larvae, the original oil of C. citriodora was less effective than the counterpart modified oil (N7), proving that the chemical modification optimized its effect. In the in vivo test, no significant difference was observed between N7 and the negative control. The average numbers of ticks on the animals' right side were 32.8, 8.1, 37.9 and 35.4 for the negative control, positive control, original oil and N7, respectively. The chemical modification improved the efficacy in vitro, but it was not observed in vivo, perhaps due to the low stability of the amines under field conditions. The evaluation carried out here has not been previously studied, so this concept expands the horizon for research into chemically modified substances for parasite control and shed light on the challenges to find effective formulations and application methods. PMID:25085774

Chagas, Ana Carolina S; Domingues, Luciana F; Fantatto, Rafaela R; Giglioti, Rodrigo; Oliveira, Márcia C S; Oliveira, Daniela H; Mano, Renata A; Jacob, Raquel G

2014-09-15

274

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

275

The SPORES experiment of the EXPOSE-R mission: Bacillus subtilis spores in artificial meteorites  

NASA Astrophysics Data System (ADS)

The experiment SPORES `Spores in artificial meteorites' was part of European Space Agency's EXPOSE-R mission, which exposed chemical and biological samples for nearly 2 years (March 10, 2009 to February 21, 2011) to outer space, when attached to the outside of the Russian Zvezda module of the International Space Station. The overall objective of the SPORES experiment was to address the question whether the meteorite material offers enough protection against the harsh environment of space for spores to survive a long-term journey in space by experimentally mimicking the hypothetical scenario of Lithopanspermia, which assumes interplanetary transfer of life via impact-ejected rocks. For this purpose, spores of Bacillus subtilis 168 were exposed to selected parameters of outer space (solar ultraviolet (UV) radiation at ?>110 or >200 nm, space vacuum, galactic cosmic radiation and temperature fluctuations) either as a pure spore monolayer or mixed with different concentrations of artificial meteorite powder. Total fluence of solar UV radiation (100-400 nm) during the mission was 859 MJ m-2. After retrieval the viability of the samples was analysed. A Mission Ground Reference program was performed in parallel to the flight experiment. The results of SPORES demonstrate the high inactivating potential of extraterrestrial UV radiation as one of the most harmful factors of space, especially UV at ?>110 nm. The UV-induced inactivation is mainly caused by photodamaging of the DNA, as documented by the identification of the spore photoproduct 5,6-dihydro-5(?-thyminyl)thymine. The data disclose the limits of Lithopanspermia for spores located in the upper layers of impact-ejected rocks due to access of harmful extraterrestrial solar UV radiation.

Panitz, Corinna; Horneck, Gerda; Rabbow, Elke; Rettberg, Petra; Moeller, Ralf; Cadet, Jean; Douki, Thierry

2015-01-01

276

Biological monitoring of workers exposed to ethylbenzene and co-exposed to xylene  

Microsoft Academic Search

Objective: Ethylbenzene is an important constituent of widely used solvent mixtures in industry. The objective of the present study\\u000a was to provide information about biological monitoring of occupational exposure to ethylbenzene, and to review the biological\\u000a limit values corresponding to the threshold limit value of ethylbenzene. Methods: A total of 20 male workers who had been exposed to a mixture

J.-Y. Jang; P. O. Droz; S. Kim

2000-01-01

277

Neurotoxicity of Acrylamide in Exposed Workers  

PubMed Central

Acrylamide (ACR) is a water-soluble chemical used in different industrial and laboratory processes. ACR monomer is neurotoxic in humans and laboratory animals. Subchronic exposure to this chemical causes neuropathies, hands and feet numbness, gait abnormalities, muscle weakness, ataxia, skin and in some cases, cerebellar alterations. ACR neurotoxicity involves mostly the peripheral but also the central nervous system, because of damage to the nerve terminal through membrane fusion mechanisms and tubulovescicular alterations. Nevertheless, the exact action mechanism is not completely elucidated. In this paper we have reviewed the current literature on its neurotoxicity connected to work-related ACR exposure. We have analyzed not only the different pathogenetic hypotheses focusing on possible neuropathological targets, but also the critical behavior of ACR poisoning. In addition we have evaluated the ACR-exposed workers case studies. Despite all the amount of work which have being carried out on this topic more studies are necessary to fully understand the pathogenetic mechanisms, in order to propose suitable therapies. PMID:23985770

Pennisi, Manuela; Malaguarnera, Giulia; Puglisi, Valentina; Vinciguerra, Luisa; Vacante, Marco; Malaguarnera, Mariano

2013-01-01

278

Cytogenetic analyses of mice exposed to dichloromethane  

SciTech Connect

Chromosome damage was studied in female B6C3F1 mice exposed to dichloromethane (DCM) by subcutaneous or inhalation treatments. No increase in either the frequencies of sister chromatid exchanges (SCEs) or chromosome aberrations (CAs) in bone marrow cells was observed after a single subcutaneous injection of either 2,500 or 5,000 mg/kg DCM. Inhalation exposure to DCM for 10 days at doses of 4,000 or 8,000 ppm resulted in significant increases in frequencies of SCEs in lung cells and peripheral blood lymphocytes, CAs in lung and bone marrow cells, and micronuclei (MN) in peripheral blood erythrocytes. Lung cell CAs and blood erythrocyte MN reached frequencies of approximately two times control levels. Following a 3-month inhalation exposure to 2,000 ppm DCM, mice showed small but significant increases in lung cell SCEs and peripheral blood erythrocyte MN. These findings suggest that genotoxicity may play a role in the carcinogenicity of DCM in the lungs of B6C3F1 female mice.

Allen, J.; Kligerman, A.; Campbell, J.; Westbrook-Collins, B.; Erexson, G.

1990-01-01

279

Cytogenetic analyses of mice exposed to dichloromethane  

SciTech Connect

Chromosome damage was studied in female B6C3F1 mice exposed to dichloromethane (DCM) by subcutaneous or inhalation treatments. No increase in the frequency of either sister chromatid exchanges (SCEs) or chromosome aberrations (CAs) in bone marrow cells was observed after a single subcutaneous injection of 2,500 or 5,000 mg/kg DCM. Inhalation exposure to DCM for 10 days at concentrations of 4,000 or 8,000 ppm resulted in significant increases in frequencies of SCEs in lung cells and peripheral blood lymphocytes, CAs in lung and bone marrow cells, and micronuclei (MN) in peripheral blood erythrocytes. Lung cell CAs and blood erythrocyte MN reached frequencies of approximately two times control levels. Following a 3-month inhalation exposure to 2,000 ppm DCM, mice showed small but significant increases in lung cell SCEs and peripheral blood erythrocyte MN. These findings suggest that genotoxicity may play a role in the carcinogenicity of DCM in the lungs of B6C3F1 female mice.

Allen, J.; Kligerman, A.; Campbell, J.; Westbrook-Collins, B.; Erexson, G.; Kari, F.; Zeiger, E. (National Institute of Environmental Health Sciences, Research Triangle Park, NC (USA))

1990-01-01

280

Thyroid hormones in chronic heat exposed men  

NASA Astrophysics Data System (ADS)

Previous reports have indicated that thyroid gland activity, is depressed in the heat. Total thyroxine (T4) and triiodothyronine (T3) serum levels in 17 workers of the metal work shop at a plant near the Dead Sea and 8 workers in Beer Sheva, Israel were examined. The metal workshop of the plant near the Dead Sea is part of a large chemical plant. The one in Beer Sheva is part of a large construction company. Maintenance work, as well as metal work projects are performed in both workshops. During the work shifts, the workers of the Dead Sea plant were exposed to temperatures ranging from 30 36°C (May Oct.) and 14 21°C (Dec. Feb). In Beer Sheva the range was 25 32°C (June Sept.) and 10 17°C (Dec. Feb.). Total T4 was measured by competitive protein binding and total T3 by radioimmunoassay in blood drawn before work (0700) in July and January. In summer. T4 was higher and T3 was lower for both groups than in winter. The observed summer T3 decrease may result from depressed extrathyroidal conversion of T4 to T3. We conclude that the regulation of energy metabolism in hot climates may be related to extrathyroidal conversion of T4 to T3.

Gertner, A.; Israeli, R.; Lev, A.; Cassuto, Y.

1983-03-01

281

Degradation of HEPA filters exposed to DMSO  

SciTech Connect

Dimethyl sulfoxide (DMSO) sprays are being used to remove the high explosive (HE) from nuclear weapons in the process of their dismantlement. A boxed 50 cfm HEPA filter with an integral prefilter was exposed to DMSO vapor and aerosols that were generated by a spray nozzle to simulate conditions expected in the HE dissolution operation. After 198 hours of operation, the pressure drop of the filter had increased from 1.15 inches to 2.85 inches, and the efficiency for 0.3 {mu}m dioctyl sebacate (DOS) aerosols decreased from 99.992% to 98.6%. Most of the DMSO aerosols had collected as a liquid pool inside the boxed HEPA. The liquid was blown out of the filter exit with 100 cfm air flow at the end of the test. Since the filter still met the minimum allowed efficiency of 99.97% after 166 hours of exposure, we recommend replacing the filter every 160 hours of operation or sooner if the pressure drop increases by 50%. Examination of the filter showed that visible cracks appeared at the joints of the wooden frame and a portion of the sealant had pulled away from the frame. Since all of the DMSO will be trapped in the first HEPA filter, the second HEPA filter should not suffer from DMSO degradation. Thus the combined efficiency for the first filter (98.6%) and the second filter (99.97%) is 99.99996% for 0.3{mu}m particles. If the first filter is replaced prior to its degradation, each of the filters will have 99.97% efficiency, and the combined efficiency will be 99.999991%. The collection efficiency for DMSO/HE aerosols will be much higher because the particle size is much greater.

Bergman, W.; Wilson, K.; Larsen, G.; Lopez, R.; LeMay, J.

1994-07-11

282

Animal Cruelty by Children Exposed to Domestic Violence  

ERIC Educational Resources Information Center

Objective: The 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. Method: A…

Currie, Cheryl L.

2006-01-01

283

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

284

BIOMARKERS IN THE MOLECULAR EPIDEMIOLOGY OF BENZENE-EXPOSED WORKERS  

E-print Network

BIOMARKERS IN THE MOLECULAR EPIDEMIOLOGY OF BENZENE-EXPOSED WORKERS Martyn T. Smith Division from workers exposed to high levels of benzene. The goal of these studies is to develop and validate (1) biomarkers of exposure to benzene, such as albumin or hemoglobin adducts; (2) molecular markers

California at Berkeley, University of

285

Children Exposed to Community Violence: The Rationale for Early Intervention  

Microsoft Academic Search

Children are exposed to violence in their homes and communities at extraordinarily high rates. Given the alarming rates of exposure and its known impact on child developmental outcomes, crisis intervention geared at interrupting the negative effects of violence exposure are increasingly important. This review provides a rationale for the implementation of early and crisis intervention strategies for children exposed to

Steven J. Berkowitz

2003-01-01

286

Wheat flour exposed to ethanol yields dough with unexpected properties  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wheat flour may be exposed to ethanol solutions in such a way as to alter the subsequent transformation of the flour into dough. Here, a number of types of wheat flour were exposed to small amounts of ethanol solutions so as to be "wetted" but without the appearance of a separate liquid phase. The...

287

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

288

CEREBELLAR HISTOGENESIS IN RATS EXPOSED TO 2450 MHZ MICROWAVE RADIATION  

EPA Science Inventory

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 without any treatment, an...

289

METABOLISM OF BLOOD GLUCOSE IN COLD EXPOSED SHEEP  

E-print Network

METABOLISM OF BLOOD GLUCOSE IN COLD EXPOSED SHEEP T. TSUDA M. FUJITA K. AMBO Department of Animal of blood glucose metabolism and of glucogenic pre- cursors were measured in cold-exposed ewes. Material of Bergman (1963). Results and Discussion 1. Blood glucose metabolism U-14C-glucose was infused i

Paris-Sud XI, Université de

290

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

291

Comparative Study of the Phonology of Preschool Children Prenatally Exposed to Cocaine and Multiple Drugs and Non-Exposed Children.  

ERIC Educational Resources Information Center

This study compared phonological patterns in the speech of 25 children prenatally exposed to cocaine and multiple drugs and with 25 non-exposed children (all children ages 22 to 51 months). Prenatal exposure to drugs was associated with an increase in the use of phonological processes. Results suggest that these children's speech development is…

Madison, Charles L.; Johnson, Jeanne M.; Seikel, J. Anthony; Arnold, Marjorie; Schultheis, Leanne

1998-01-01

292

Comparative study of the phonology of preschool children prenatally exposed to cocaine and multiple drugs and non-exposed children  

Microsoft Academic Search

Cocaine and multiple drug abuse among young adults has spawned research interest in fetal exposure and the sequela of that exposure during the formative developmental years. Previous study of the language development of exposed children has not specifically addressed phonological acquisition. In the present study, the speech of 25 children prenatally exposed to cocaine and multiple drugs was analyzed and

Charles L Madison; Jeanne M Johnson; J. Anthony Seikel; Marjorie Arnold; Leanne Schultheis

1998-01-01

293

APPLICATION OF CONTACT ACARICIDE AGAINST VARROA MITES  

E-print Network

. The preparation was put in a sickle-like arrangement in empty cells in the central area of the combs. These combs/5 of the whole comb area had a sickle-like shape facing the bottom of the frame and occupied a position slightly against adult honey bees was also studied by marking sixty worker bees immediately after their emerging

Paris-Sud XI, Université de

294

The AMINO experiment: RNA stability under solar radiation studied on the EXPOSE-R facility of the International Space Station  

NASA Astrophysics Data System (ADS)

Careful examination of the present metabolism and in vitro selection of various catalytic RNAs strongly support the RNA world hypothesis as a crucial step of the origins and early life evolution. Small functional RNAs were exposed from 10 March 2009 to 21 January 2011 to space conditions on board the International Space Station in the EXPOSE-R mission. The aim of this study was to investigate the preservation or modification properties such as integrity of RNAs after space exposition. The exposition to the solar radiation has a strong degradation effect on the size distribution of RNA. Moreover, the comparison between the in-flight samples, exposed to the Sun and not exposed, indicates that the solar radiation degrades RNA bases.

Vergne, Jacques; Cottin, Hervé; da Silva, Laura; Brack, André; Chaput, Didier

2015-01-01

295

The differences in phenolic content in rivers exposed and non-exposed to anthropogenic contamination.  

PubMed

The purpose of the work was to determine the differences in a kind, number and concentrations of phenol, chlorophenols, chlorocatechols chlorinated methoxyphenols (chloroguaiacols, chlorosyringols) and 3,4,5-trichloroveratrole in the drainage of the Dzierzazna river, the flow non-exposed to anthropogenic contamination and in the Ner river, the flow exposed to anthropogenic pollution. The samples of water were collected in the Dzierzazna river in the Swoboda locality, the inflow of the Dzierzazna river - the Ciosenka river and, also, in the spring situated in Ciosny Sady locality. Water of the Ner river was collected in points near ?ód?, Konstantynów, Poddebice and Dabie towns. The compounds were condensed (adsorbed) and eluted with methylene chloride on octadecyl C18 layer in a Baker Separex system. The obtained eluent was separated using the method of gas chromatography and analysed using mass spectrometry technique. In samples collected from the drainage of the Dzierzazna river phenol, chlorophenols, guaiacol, trichloroguaiacol, tetrachloroguaiacol, trichlorosyringol and 3,4,5-trichloroveratole were determined. As no anthropogenic sources are situated within the drainage of the Dzierzazna river, we may suppose that most of the determined compounds are mainly of natural origin. No or trace concentrations of chlorinated methoxyphenols were noted in the water of the Ner river, but a higher number, and concentrations of chlorophenols and additionally chlorocatechols were determined in this flow. It is also apparent that changes in a number and concentrations of phenols in the water of the Ner river did not prove a seasonal character, which was typical of the Dzierzazna drainage waters. PMID:18048080

Micha?owicz, Jaromir; Bukowska, Bozena; Duda, Wirgiliusz

2008-03-01

296

Non-disjunction mutations in Drosophila exposed to magnetic fields  

NASA Astrophysics Data System (ADS)

The frequency of XO mutations in Drosophila melanogaster was significantly higher than normal in magnetic field exposed, immature males, than in exposed, mature males. Mutation levels increased with magnetic field strength. Intercellular rings of black magnetic particles were formed in the high magnetic flux region of dorsally exposed, early stage pupae and to a lesser degree in the abdomen of young adult females. Orientation of minute, chromosome associated, magnetic domains within the microenvironment of the developing organism was believed to alter oxidative processes within maturing X+ sperm which during fertilization were incompatible with and destructive to an Xw chromosome in the zygote.

Levengood, W. C.

1987-09-01

297

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...

298

RESPIRATORY DAMAGE IN CHILDREN EXPOSED TO URBAN POLLUTION  

EPA Science Inventory

Southwest Metropolitan Mexico City (SWMMC) children are chronically exposed to complex mixtures of air pollutants. In a cross-sectional arm of our study, we investigated the association between exposure to SWMMC atmosphere and nasal abnormalities, hyperinflation, and intersti...

299

Detail view of the exposed polychromatic aggregate ceiling designed and ...  

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

Detail view of the exposed polychromatic aggregate ceiling designed and cast by John Joseph Earley for the vehicular entrance portals to the courtyard - United States Department of Justice, Constitution Avenue between Ninth & Tenth Streets, Northwest, Washington, District of Columbia, DC

300

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...

301

Air Force Reservists Exposed to Agent Orange: Report  

MedlinePLUS

... enable JavaScript. Air Force Reservists Exposed to Agent Orange: Report The exposure came years after planes dropped ... had been used to spray the defoliant Agent Orange during the Vietnam War could have experienced "adverse ...

302

Mortality in an European cohort occupationally exposed to Epichlorohydrin (ECH)  

Microsoft Academic Search

Summary A study was undertaken on the mortality of workers exposed to ECH at four European sites with plants producing epichlorohydrin (ECH), epoxy resins, glycerin, and other speciality chemicals derived from ECH.

J. P. Tassignon; G. D. Bos; A. A. Craigen; B. Jacquet; H. L. Kueng; C. Lanouziere-Simon; C. Pierre

1983-01-01

303

19. FIRST FLOOR, NORTHEAST ROOM LOOKING EAST, DETAIL OF EXPOSED ...  

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

19. FIRST FLOOR, NORTHEAST ROOM LOOKING EAST, DETAIL OF EXPOSED LOG WALL AND RUBBLE FOUNDATION - Stiegel House, East side State Route 419, North of intersection of State Route 419 & State Route 897 (Heidelberg Township), Schaefferstown, Lebanon County, PA

304

20. EXTERIOR DETAIL VIEW OF EXPOSED REDWOOD PILE UNDER NORTHEAST ...  

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

20. EXTERIOR DETAIL VIEW OF EXPOSED REDWOOD PILE UNDER NORTHEAST WING ABUTMENT, LOOKING SOUTH TO NORTH - Rowdy Creek Bridge, Spanning Rowdy Creek at Fred Haight Drive, Smith River, Del Norte County, CA

305

7. FOUNDATIONS OF FLUME NO. 8, EXPOSED. SCE negative no. ...  

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

7. FOUNDATIONS OF FLUME NO. 8, EXPOSED. SCE negative no. 3077, January 26, 1916. Photograph by G. Haven Bishop. - Santa Ana River Hydroelectric System, Flumes & Tunnels below Sandbox, Redlands, San Bernardino County, CA

306

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...

307

Cytogenetic study of persons occupationally exposed to ethylene oxide.  

PubMed

Ten persons occupationally exposed to ethylene oxide (EO), used in the sterilization of medical instruments, were studied at a hospital. The estimated concentration to which they were exposed was 60-69 ppm, TWA. Peripheral blood samples from 10 workers and 10 controls of the same age and sex were taken to determine the frequency of sister-chromatid exchanges (SCE) and chromosomal aberrations (CA). The mean frequencies of SCE/cell (X = S) were 13.27 for the exposed workers and 6.05 for controls. Chromosome aberration frequencies in exposed individuals were significantly increased compared with controls. A significant relationship between the frequencies of SCE and CA and EO exposure was demonstrated. Blood chemistry parameters such as urea, creatinine, uric acid, lactic dehydrogenase, glutamic oxaloacetic and pyruvic transaminases, luteinizing gonadotropin and follicle stimulating gonadotropin and thyrotropin were also measured and found to be within the normal range. PMID:1371589

Lerda, D; Rizzi, R

1992-01-01

308

Epidemiologic study of workers exposed to titanium dioxide  

SciTech Connect

The objective of this study was to determine whether workers exposed to titanium dioxide (TiO/sub 2/) had significantly higher risks of lung cancer, chronic respiratory disease, pleural thickening/plaques, or pulmonary fibrosis than referent groups. A total of 1,576 employees exposed to TiO/sub 2/ were observed from 1956 through 1985 for cancer and chronic respiratory disease incidence, and from 1935 through 1983 for mortality. A cross-sectional sample of 398 employees was evaluated for chest roentgenogram abnormalities. Cohort analyses suggested that the risks of developing lung cancer and other fatal respiratory diseases were no higher for TiO/sub 2/-exposed employees than for the referent groups. Nested case-control analyses found no statistically significant associations between TiO/sub 2/ exposure and risk of lung cancer, chronic respiratory disease, and chest roentgenogram abnormalities. No cases of pulmonary fibrosis were observed among TiO/sub 2/-exposed employees.

Chen, J.L.; Fayerweather, W.E.

1988-12-01

309

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...

310

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...

311

Partially exposed polymer dispersed liquid crystals for boundary layer investigations  

NASA Technical Reports Server (NTRS)

A new configuration termed partially exposed polymer dispersed liquid crystal in which the liquid crystal microdroplets dispersed in a rigid polymer matrix are partially entrapped on the free surface of the thin film deposited on a glass substrate is reported. Optical transmission characteristics of the partially exposed polymer dispersed liquid crystal thin film in response to an air flow induced shear stress field reveal its potential as a sensor for gas flow and boundary layer investigations.

Parmar, Devendra S.; Singh, Jag J.

1992-01-01

312

Qualitative color vision impairment in toluene-exposed workers  

Microsoft Academic Search

Objective?: The aim of this study was to evaluate whether toluene, like many other organic solvents and solvent mixtures, could impair\\u000a color vision. Subjects and methods?: We investigated color vision impairment in three groups of workers, two groups occupationally exposed to toluene and a\\u000a nonexposed group. The first exposed group, group E1, comprised 41 workers (median value of toluene in

M. Zavali?; Z. Mandi?; R. Turk; A. Bogadi-Šare; D. Plavec; L. J. Skender

1998-01-01

313

Methamphetamine self-administration in rats developmentally exposed to lead  

E-print Network

METHAMPHETAMINE SELF-ADMINISTRATION IN RATS DEVELOPMENTALLY EXPOSED TO LEAD A Dissertation by ANGELICA ROCHA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of DOCTOR OF PHILOSOPHY May 2007 Major Subject: Psychology METHAMPHETAMINE SELF-ADMINISTRATION IN RATS DEVELOPMENTALLY EXPOSED TO LEAD A Dissertation by ANGELICA ROCHA Submitted to the Office...

Rocha, Angelica

2009-05-15

314

Visual evoked potentials in rotogravure printers exposed to toluene  

Microsoft Academic Search

Visual evoked potentials (VEPs) from stimulation by checkerboard pattern reversal were examined in 54 rotogravure printers exposed to toluene (all men, aged 22-64 years, duration of exposure 1-41 years). A control group consisted of 46 subjects (23 men and 23 women; aged 22-54 years). Compared with controls the exposed group showed more frequent responses with reduced reproducibility or absence of

P Urban; E Lukás

1990-01-01

315

Ozone exposed epithelial cells modify cocultured natural killer cells  

PubMed Central

Ozone (O3) causes significant adverse health effects worldwide. Nasal epithelial cells (NECs) are among the first sites within the respiratory system to be exposed to inhaled air pollutants. They recruit, activate, and interact with immune cells via soluble mediators and direct cell-cell contacts. Based on our recent observation demonstrating the presence of natural killer (NK) cells in nasal lavages, the goal of this study was to establish a coculture model of NECs and NK cells and examine how exposure to O3 modifies this interaction. Flow cytometry analysis was used to assess immunophenotypes of NK cells cocultured with either air- or O3-exposed NECs. Our data show that coculturing NK cells with O3-exposed NECs decreased intracellular interferon-? (IFN-?), enhanced, albeit not statistically significant, IL-4, and increased CD16 expression on NK cells compared with air controls. Additionally, the cytotoxicity potential of NK cells was reduced after coculturing with O3-exposed NECs. To determine whether soluble mediators released by O3-exposed NECs caused this shift, apical and basolateral supernatants of air- and O3-exposed NECs were used to stimulate NK cells. While the conditioned media of O3-exposed NECs alone did not reduce intracellular IFN-?, O3 enhanced the expression of NK cell ligands ULBP3 and MICA/B on NECs. Blocking ULBP3 and MICA/B reversed the effects of O3-exposed NECs on IFN-? production in NK cells. Taken together, these data showed that interactions between NECs and NK cells in the context of O3 exposure changes NK cell activity via direct cell-cell interactions and is dependent on ULBP3/MICA/B expressed on NECs. PMID:23241529

Müller, Loretta; Brighton, Luisa E.

2013-01-01

316

The AMINO experiment: methane photolysis under Solar VUV irradiation on the EXPOSE-R facility of the International Space Station  

NASA Astrophysics Data System (ADS)

The scientific aim of the present campaign is to study the whole chain of methane photo-degradation, as initiated by Solar vacuum-ultraviolet irradiation in Titan's atmosphere. For this purpose, the AMINO experiment on the EXPOSE-R mission has loaded closed cells for gas-phase photochemistry in space conditions. Two different gas mixtures have been exposed, named Titan 1 and Titan 2, involving both N2-CH4 gas mixtures, without and with CO2, respectively. CO2 is added as a source of reactive oxygen in the cells. The cell contents were analysed thanks to infrared absorption spectroscopy, gas chromatography and mass spectrometry. Methane consumption leads to the formation of saturated hydrocarbons, with no detectable influence of CO2. This successful campaign provides a first benchmark for characterizing the whole methane photochemical system in space conditions. A thin film of tholin-like compounds appears to form on the cell walls of the exposed cells.

Carrasco, Nathalie; Cottin, Hervé; Cloix, Mégane; Jérome, Murielle; Bénilan, Yves; Coll, Patrice; Gazeau, Marie-Claire; Raulin, François; Saiagh, Kafila; Chaput, Didier

2015-01-01

317

Presence of Cd?binding proteins in pre?exposed and not pre?exposed cadmium brine shrimp Artemia  

Microsoft Academic Search

The presence of metal binding proteins has been variously suggested as indicating involvement in uptake, storage, transport and elimination of toxic metals and in the routine metabolism of metals in mammals and a variety of marine invertebrates. This report describes results on the characterization of Cd?BPs obtained from cadmium pre?exposed and not pre?exposed Anemia. The effect of pre?exposure in the

M. Martínez; J. Del Ramo; A. Torreblanca; A. Pastor

1991-01-01

318

Assessment of oxidative stress in Rhamdia quelen exposed to agrichemicals.  

PubMed

Due to the proximity of crop and fish culture areas, some agrichemicals that could be harmful for fish could enter into fishponds by different ways, such as by leaching through rain. Rhamdia quelen (Teleostei) were exposed to sublethal concentrations of methyl parathion (MP), a glyphosate based herbicide (Gly), and tebuconazole (Teb). The liver of R. quelen exposed to MP and Teb showed enhanced levels of thiobarbituric acid reactive substances (TBARS), higher than in the control fish (56% and 59%, respectively). In contrast, Gly did not alter the TBARS generation. The protein carbonyl content increased only in fish exposed to Teb. Fish exposed to the three agrichemicals showed a significant decrease of catalase activity (52%, 48%, and 67%, respectively) and increased glutathione-S-transferase (57%, 46%, and 160%, respectively) activity. Fish exposed to MP, Gly, and Teb showed higher reduced glutathione (151%, 472%, and 130%, respectively, when compared with the control levels) and ascorbic acid concentrations (121%, 102%, and 184%, respectively),while the non-protein thiol content increased only in R. quelen exposed to tebuconazole. Fish exposed to MP and Teb showed several pathological changes in the liver, including hepatocyte degeneration and bile stagnation. The present work reports for the first time the toxicity of the pesticide MP and the fungicide Teb in R. quelen, and as in other works, suggests the relatively lower liver toxicity of Gly for fish. The data presented herein demonstrate that sublethal concentrations of MP and Teb cause changes in oxidative stress parameters as well as hepatic cell injuries in R. quelen, and that these parameters have the potential to be developed as bioindicators of exposure to these agrichemicals. PMID:20371099

Ferreira, Daiane; da Motta, Adriana Costa; Kreutz, Luiz Carlos; Toni, Cândida; Loro, Vânia Lucia; Barcellos, Leonardo José Gil

2010-05-01

319

Neurodevelopmental outcomes in HIV-exposed-uninfected children versus those not exposed to HIV.  

PubMed

Human immunodeficiency virus (HIV)-negative children born to HIV-infected mothers may exhibit differences in neurodevelopment (ND) compared to age- and gender-matched controls whose lives have not been affected by HIV. This could occur due to exposure to HIV and antiretroviral agents in utero and perinatally, or differences in the environment in which they grow up. This study assessed neurodevelopmental outcomes in HIV-exposed uninfected (HEU) and HIV-unexposed uninfected (HUU) children enrolled as controls in a multicenter ND study from Thailand and Cambodia. One hundred sixty HEU and 167 HUU children completed a neurodevelopmental assessment using the Beery Visual Motor Integration (VMI) test, Color Trails, Perdue Pegboard, and Child Behavior Checklist (CBCL). Thai children (n = 202) also completed the Wechsler Intelligence Scale (IQ) and Stanford-Binet II memory tests. In analyses adjusted for caregiver education, parent as caregiver, household income, age, and ethnicity, statistically significant lower scores were seen on verbal IQ (VIQ), full-scale IQ (FSIQ), and Binet Bead Memory among HEU compared to HUU. The mean (95% CI) differences were -6.13 (-10.3 to -1.96), p = 0.004; -4.57 (-8.80 to -0.35), p = 0.03; and -3.72 (-6.57 to -0.88), p = 0.01 for VIQ, FSIQ, and Binet Bead Memory, respectively. We observed no significant differences in performance IQ, other Binet memory domains, Color Trail, Perdue Pegboard, Beery VMI, or CBCL test scores. We conclude that HEU children evidence reductions in some neurodevelopmental outcomes compared to HUU; however, these differences are small and it remains unclear to what extent they have immediate and long-term clinical significance. PMID:24878112

Kerr, Stephen J; Puthanakit, Thanyawee; Vibol, Ung; Aurpibul, Linda; Vonthanak, Sophan; Kosalaraksa, Pope; Kanjanavanit, Suparat; Hansudewechakul, Rawiwan; Wongsawat, Jurai; Luesomboon, Wicharn; Ratanadilok, Kattiya; Prasitsuebsai, Wasana; Pruksakaew, Kanchana; van der Lugt, Jasper; Paul, Robert; Ananworanich, Jintanat; Valcour, Victor

2014-01-01

320

42 CFR 84.86 - Component parts exposed to oxygen pressures; minimum requirements.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Component parts exposed to oxygen pressures; minimum requirements. 84...84.86 Component parts exposed to oxygen pressures; minimum requirements...construction of component parts exposed to oxygen pressures above atmospheric pressure...

2010-10-01

321

42 CFR 84.86 - Component parts exposed to oxygen pressures; minimum requirements.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Component parts exposed to oxygen pressures; minimum requirements. 84...84.86 Component parts exposed to oxygen pressures; minimum requirements...construction of component parts exposed to oxygen pressures above atmospheric pressure...

2011-10-01

322

42 CFR 84.86 - Component parts exposed to oxygen pressures; minimum requirements.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Component parts exposed to oxygen pressures; minimum requirements. 84...84.86 Component parts exposed to oxygen pressures; minimum requirements...construction of component parts exposed to oxygen pressures above atmospheric pressure...

2014-10-01

323

42 CFR 84.86 - Component parts exposed to oxygen pressures; minimum requirements.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Component parts exposed to oxygen pressures; minimum requirements. 84...84.86 Component parts exposed to oxygen pressures; minimum requirements...construction of component parts exposed to oxygen pressures above atmospheric pressure...

2012-10-01

324

42 CFR 84.86 - Component parts exposed to oxygen pressures; minimum requirements.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Component parts exposed to oxygen pressures; minimum requirements. 84...84.86 Component parts exposed to oxygen pressures; minimum requirements...construction of component parts exposed to oxygen pressures above atmospheric pressure...

2013-10-01

325

75 FR 43184 - Transport of Laboratory Personnel Potentially Exposed to Infectious Agents From Fort Detrick...  

Federal Register 2010, 2011, 2012, 2013, 2014

...State Police. Based on the potentially exposed individual's condition...basis, and not provide the potentially exposed individual with the...extended stay of individuals potentially exposed to infectious agents...NIH Transportation EIS. Any adverse environmental effects...

2010-07-23

326

Martius graft for management of exposed vaginal prolapse mesh.  

PubMed

Although the use of vaginal mesh kits in treatment of pelvic organ prolapse (POP) has decreased the number of surgical failures, mesh exposure can occur. When conservative management fails, removing the exposed material is associated with the risk of recurrence of POP and could be challenging. We report a successful outcome of treatment of exposed mesh via use of a Martius bulbocavernosus fat pad. A 46-year-old woman had urinary incontinence and POP, which was treated using a vaginal mesh kit and tension-free vaginal tape. At 2 months after the procedure, the mesh was found to be exposed. After failed conservative management, use of a Martius graft was used, with preservation of the mesh. At 2-, 5-, and 10-month follow-up, the patient was completely asymptomatic and continent. This procedure may be a practical alternative in patients with synthetic mesh-induced vaginal erosion after failed conservative management. PMID:23295200

Al-Badr, Ahmed

2013-01-01

327

Asbestos content in lungs of occupationally and nonoccupationally exposed individuals  

SciTech Connect

Previous reports have indicated that a majority of the population has asbestos bodies within their lungs. These studies generally have been carried out using cohorts from urban environments. The present study compares the asbestos body levels from three unique cohorts: (1) a nonoccupationally exposed group from a large urban environment having a relatively low asbestos content, (2) patients with lung cancer from a nonurban setting, and (3) amosite asbestos workers, who worked and lived in a rural setting. The number of asbestos bodies in both the urban nonoccupationally exposed group and the patients with lung cancer was generally found to be low or below limits of detectability, with the exceptions being those persons in whom an occupational exposure was eventually found. The ferruginous body content of the occupationally exposed group varied considerably between individuals as well as between sites within the same individual.

Dodson, R.F.; Greenberg, S.D.; Williams, M.G. Jr.; Corn, C.J.; O'Sullivan, M.F.; Hurst, G.A.

1984-07-06

328

Semen quality in workers exposed to 2-ethoxyethanol.  

PubMed Central

To evaluate whether long term exposure to 2-ethoxyethanol (2EE) may affect semen quality, a cross sectional study was conducted among men exposed to 2EE used as a binder slurry in a metal castings process. Full shift breathing zone exposures to 2EE ranged from non-detectable to 24 ppm (geometric mean 6.6 ppm). Because of the potential for substantial absorption of 2EE through skin exposure, urine measurements of the metabolite of 2EE, 2-ethoxyacetic acid (2EAA) were conducted, showing levels of 2EAA ranging from non-detectable to 163 mg 2EAA/g creatinine. Only 37 exposed men (50% participation) and 39 non-exposed comparison (26% participation) from elsewhere in the plant provided a sperm sample. A questionnaire to determine personal habits, and medical and work histories, and a physical examination of the urogenital tract were also administered. The average sperm count per ejaculate among the workers exposed to 2EE was significantly lower than that of the unexposed group (113 v 154 million sperm per ejaculate respectively; p = 0.05) after consideration of abstinence, sample age, subjects' age, tobacco, alcohol and caffeine use, urogenital disorders, fever, and other illnesses. The mean sperm concentrations of the exposed and unexposed groups did not significantly differ from each other (44 and 53 million/ml respectively). No effect of exposure to 2EE on semen volume, sperm viability, motility, velocity, and normal morphology or testicular volume was detected, although some differences in the proportion of abnormal sperm shapes were observed. These data suggest that there may be an effect of 2EE on sperm count among these workers, although the possibility that other factors may be affecting the semen quality in both exposed and unexposed men in this population or that the results reflect bias introduced by the low participation rates cannot be excluded. PMID:2818974

Ratcliffe, J M; Schrader, S M; Clapp, D E; Halperin, W E; Turner, T W; Hornung, R W

1989-01-01

329

Survival of Spores of Trichoderma longibrachiatum in Space: data from the Space Experiment SPORES on EXPOSE-R  

NASA Astrophysics Data System (ADS)

In the space experiment `Spores in artificial meteorites' (SPORES), spores of the fungus Trichoderma longibrachiatum were exposed to low-Earth orbit for nearly 2 years on board the EXPOSE-R facility outside of the International Space Station. The environmental conditions tested in space were: space vacuum at 10-7-10-4 Pa or argon atmosphere at 105 Pa as inert gas atmosphere, solar extraterrestrial ultraviolet (UV) radiation at ? > 110 nm or ? > 200 nm with fluences up to 5.8 × 108 J m-2, cosmic radiation of a total dose range from 225 to 320 mGy, and temperature fluctuations from -25 to +50°C, applied isolated or in combination. Comparable control experiments were performed on ground. After retrieval, viability of spores was analysed by two methods: (i) ethidium bromide staining and (ii) test of germination capability. About 30% of the spores in vacuum survived the space travel, if shielded against insolation. However, in most cases no significant decrease was observed for spores exposed in addition to the full spectrum of solar UV irradiation. As the spores were exposed in clusters, the outer layers of spores may have shielded the inner part. The results give some information about the likelihood of lithopanspermia, the natural transfer of micro-organisms between planets. In addition to the parameters of outer space, sojourn time in space seems to be one of the limiting parameters.

Neuberger, Katja; Lux-Endrich, Astrid; Panitz, Corinna

2015-01-01

330

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

331

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

332

Organic samples produced by ion bombardment of ices for the EXPOSE-R2 mission on the International Space Station  

NASA Astrophysics Data System (ADS)

We describe the preparation and characterization (by UV-Vis-IR spectroscopy) of a set of organic samples, stable at room temperature and above, that are part of the experiment "Photochemistry on the Space Station (PSS)" planned to be enclosed in the EXPOSE-R2 mission, which will be conducted on the EXPOSE-R facility, outside the International Space Station (ISS). The organic materials are prepared in the Catania laboratory after 200 keV He+ irradiation of icy mixtures, namely N_2:CH_4:CO deposited at 16 K on MgF_2 windows furnished by European Space Agency. It is widely accepted that such kind of materials produced by energetic processing are representative of organic material in astrophysical environments such as, e.g., comets. Once expelled from comets these materials are exposed to solar radiation during their interplanetary journey before they eventually land on the Earth and other planetary objects where they might give a contribution to the chemical and pre-biotical evolution. In particular our residues contain different chemical groups, including triple CN bonds that are considered relevant to pre-biotic chemistry (e.g. Palumbo et al., 2000). Therefore the samples will be exposed, for several months, to the solar ultraviolet photons that are a major source of energy to initiate chemical evolution in the Solar System. This will allow analysis of their destruction and evaluation of their lifetime in the interplanetary medium. The samples have three different thicknesses (about 200, 130, 65 nm) that will allow the estimation of the depth profile of destruction (e.g., Baratta et al., 2002). This experiment overcomes the limits of ground tests which do not reproduce exactly the space parameters.

Baratta, G.; Chaput, D.; Cottin, H.; Fernandez Cascales, L.; Palumbo, M.; Strazzulla, G.

2014-07-01

333

Neurobehavioural effects among workers occupationally exposed to organophosphorous pesticides  

PubMed Central

Aims: To identify neurobehavioural deficits among workers exposed to organophosphorous (OP) pesticides in their occupation. Methods: This study was conducted during the period when pesticides were applied to cotton crops in the fields in Menoufiya Governorate, Egypt. Fifty two occupationally exposed male workers were compared to 50 unexposed male controls who were similar in age, socioeconomic class, and years of education (?12 years). All participants completed a questionnaire (assessing personal, occupational, and medical histories), general and neurological clinical examination, neurobehavioural test battery (including tests for verbal abstraction, problem solving, attention, memory, and visuomotor speed), personality assessment, and serological analysis for serum acetylcholinesterase. Results: After correcting for confounders of age and education, the exposed participants exhibited significantly lower performance than controls on six neurobehavioural tests (Similarities, Digit Symbol, Trailmaking part A and B, Letter Cancellation, Digit Span, and Benton Visual Retention). A longer duration of work with pesticides was associated with lower performance on most neurobehavioural tests after adjusting for multiple comparisons. Although serum acetylcholinesterase was significantly lower in the exposed than the control participants, it was not significantly correlated with either neurobehavioural performance or neurological abnormalities. Conclusions: Occupational exposure to OP pesticides was associated with deficits in a wider array of neurobehavioural functions than previously reported, perhaps because of higher exposure in this population. Moderate chronic OP exposure may not only affect visuomotor speed as reported previously, but also verbal abstraction, attention, and memory. PMID:12660376

Farahat, T; Abdelrasoul, G; Amr, M; Shebl, M; Farahat, F; Anger, W

2003-01-01

334

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...

335

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...

336

WATER RELATIONS OF DIFFERENTIALLY IRRIGATED COTTON EXPOSED TO OZONE  

EPA Science Inventory

This field study was conducted to test the hypothesis that plants chronically exposed to be sore susceptible to drought because typically inhibits root growth and increases shoot-root ratios implants. otton was grown in open-top chambers on Hanford coarse sandy loam in Riverside,...

337

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 ...

338

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

339

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

340

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

341

BEHAVIORAL AND AUTONOMIC THERMOREGULATION IN MICE EXPOSED TO MICROWAVE RADIATION  

EPA Science Inventory

Preferred ambient temperature (T) and breathing rate were measured in free-moving mice exposed to 2,450-MHz microwaves. A waveguide-exposure system was imposed with a longitudinal temperature gradient that permitted mice to select their preferred T. Breathing rate was determined ...

342

DNA BARCODING DNA barcoding exposes a case of mistaken identity  

E-print Network

DNA BARCODING DNA barcoding exposes a case of mistaken identity in the fern horticultural trade 93312, USA Abstract Using cheilanthoid ferns, we provide an example of how DNA barcoding approaches can identification errors in the international trade. Keywords: Cheilanthes, cheilanthoids, cultivated, DNA barcoding

343

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

344

Psychological distress of adolescents exposed to Hurricane Hugo  

Microsoft Academic Search

To ascertain the effects of a natural disaster on adolescents, 1482 South Carolina high school students who were exposed to Hurricane Hugo were surveyed 1 year after the disaster. Subjects completed a self-administered questionnaire measuring Hugo exposure, nonviolent and violent life events, social support, self-efficacy, and psychological distress. Results showed that the students reported minimal exposure to the hurricane and

Sally Brosz Hardin; Martin Weinrich; Sally Weinrich; Thomas L. Hardin; Carol Garrison

1994-01-01

345

Frequency discrimination in rats exposed to noise as juveniles.  

PubMed

Sound exposure during the early postnatal period can significantly influence the function of the auditory system in rats during adulthood. In the present study, rat pups (strain Long-Evans) were exposed to broad-band noise at 125dB SPL for 8, 12 or 25min on postnatal day 14 and then at the age of 3-5months their frequency discrimination at 4 and 16kHz was assessed using a modified method of the prepulse inhibition of the acoustic startle reflex. In all groups of exposed rats, an altered frequency discrimination of the tonal stimuli was observed, in comparison with controls, at 70dB SPL. A worsening of frequency discrimination was observed even in animals exposed for 8min, the auditory thresholds of which were almost identical to that of control animals. The individual auditory thresholds did not correlate with frequency discrimination. The difference in frequency discrimination between the exposed and control animals disappeared at 85-90dB SPL. Our data suggests that brief noise exposure during the critical period of development results in the altered frequency discrimination at moderate sound intensities in adult rats, which may appear even in individuals with normal hearing thresholds. PMID:25747769

Šuta, Daniel; Rybalko, Natalia; Shen, Da-Wei; Popelá?, Ji?í; Poon, Paul W F; Syka, Josef

2015-05-15

346

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

347

Detail, oblique view to northeast atop building 935 showing exposed ...  

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

Detail, oblique view to northeast atop building 935 showing exposed roof sections of buildings 934 (center) and 933 (left), 90 mm lens. - Travis Air Force Base, Nuclear Weapons Assembly Plant 3, W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

348

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 ...

349

Youth Exposed to Violence: The Role of Protective Factors  

ERIC Educational Resources Information Center

Using a sample of 174 inner-city urban high school students, this study examined the degree to which family and peer support would moderate the negative impact of exposure to violence on academic performance, symptoms of distress, and persistence intentions. Over 94% of the students reported having been exposed to at least one form of community…

Howard, Kimberly A. S.; Budge, Stephanie L.; McKay, Kevin M.

2010-01-01

350

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

351

FLOW CYTOMETRY ANALYSIS OF WHITE TAILED DEER EXPOSED TO BVDV  

Technology Transfer Automated Retrieval System (TEKTRAN)

Two groups of four deer each, 2 to 4 weeks in age, were exposed to one of two bovine viral diarrhea virus (BVDV) strains: type 1b or type 2a, originally isolated from two different whitetail deer in southeast South Dakota in the fall of 2003. Two control age-matched deer were also used. Flow cytomet...

352

Exposing Digital Forgeries From 3-D Lighting Environments  

E-print Network

that the amount of light striking a surface is proportional to the surface normal and the direction to a singleExposing Digital Forgeries From 3-D Lighting Environments Eric Kee 1 , Hany Farid 2 Department@cs.dartmouth.edu Abstract--When creating a photographic composite, it can be difficult to match lighting conditions. We

Farid, Hany

353

LINER MATERIALS EXPOSED TO HAZARDOUS AND TOXIC 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 ...

354

Clastogenic factors in the plasma of children exposed at Chernobyl  

Microsoft Academic Search

Clastogenic factors (CFs), as they were described previously in accidentally or therapeutically irradiated persons, in A-bomb survivors and in liquidators of the Chernobyl nuclear power plant, were also detected in the plasma of Chernobyl-exposed children. A high percentage of plasma ultrafiltrates from 170 children, immigrated to Israel in 1990, exerted clastogenic effects in test cultures set up with blood from

I Emerit; M Quastel; J Goldsmith; L Merkin; A Levy; L Cernjavski; A Alaoui-Youssefi; A Pogossian; E Riklis

1997-01-01

355

CUTICULAR LESIONS INDUCED IN GRASS SHRIMP EXPOSED TO HEXAVALENT CHROMIUM  

EPA Science Inventory

Adult grass shrimp were exposed to four concentrations (0.5, 1.0, 2.0 and 4.0 ppm) of hexavalent chromium for 38 days. At the end of the exposure period, over 50% of the surviving shrimp possessed cuticular lesions that had many of the gross characteristics of 'shell disease.' Th...

356

A pill to treat people exposed to radioactive materials  

ScienceCinema

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

2014-06-24

357

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

358

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

359

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...

360

18. William E. Barrett, Photographer, August 1975. EXPOSED VIEW OF ...  

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

18. William E. Barrett, Photographer, August 1975. EXPOSED VIEW OF LOWER PULLEYS OF LEFT-HAND MILL. LOWER LEFT IS BAND SAW PULLEY. UPPER LEFT IS TENSION WHEEL. LARGE PULLEY ON RIGHT IS DRIVE WHEEL FROM POWER SOURCE. - Meadow River Lumber Company, Highway 60, Rainelle, Greenbrier County, WV

361

Proteomic Profiling of Bladders from Mice Exposed with Sodium Arsenite  

EPA Science Inventory

Arsenic, an environmental contaminant, has been linked with cancer of the bladder in humans. To study the mode of action of arsenic, female CH3 mice were exposed to 85 ppm sodium arsenite in their drinking water for 30 days. Following the exposure a comparative proteomic analysis...

362

Out-of-Home Placement of Children Exposed to Violence  

ERIC Educational Resources Information Center

There is growing concern about the increasing number of children in the USA who are exposed to community violence and the need to remove some of them from their families. This study examines risk factors for out-of-home placement among a large pool of children and adolescents who were referred for general clinical assessment following exposure to…

Harpaz-Rotem, Ilan; Berkowitz, Steven; Marans, Steven; Murphy, Robert A.; Rosenheck, Robert A.

2008-01-01

363

EXPOSE. HCI-counseling for user interface design  

Microsoft Academic Search

EXPOSE is an expert system with the objective to provide user interface designers with empirical knowledge about common practice of the application domain, with software-ergonomic (HCI-) knowledge comprised from psychology and ergonomics research findings and with procedural knowledge about a principled approach (design rationale) to user interface design. The system provides the designer with a tool to describe the design

Peter Gorny

1995-01-01

364

Asbestos content in lungs of occupationally and nonoccupationally exposed individuals  

Microsoft Academic Search

Previous reports have indicated that a majority of the population has asbestos bodies within their lungs. These studies generally have been carried out using cohorts from urban environments. The present study compares the asbestos body levels from three unique cohorts: (1) a nonoccupationally exposed group from a large urban environment having a relatively low asbestos content, (2) patients with lung

R. F. Dodson; S. D. Greenberg; M. G. Jr. Williams; C. J. Corn; M. F. OSullivan; G. A. Hurst

1984-01-01

365

I-70 Two Lift Construction Exposed Aggregate Surface  

E-print Network

.3 6Unit Wt. 3.003.002.251.504.002.50Slump 30% Slag 30% Slag 25% F-Ash 25% F-Ash 752658752658752658 30% Slag 30% Slag 25% F-Ash 25% F-Ash 752658752658752658Cementitious SD Quart SD Quart Wyo Gran Wyo%Coarse Aggregate Mix Design #12;9 Possible Test Section · Exposed Aggregate · Grind Surface

366

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

367

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

368

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

369

18. INTERIOR OF ROOM 106 LOOKING SOUTHEAST. EXPOSED BEAM AT ...  

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

18. INTERIOR OF ROOM 106 LOOKING SOUTHEAST. EXPOSED BEAM AT CEILING IS PAINTED. FLOOR IS VINYL COMPOSITION TILE. WALLS AND CEILING ARE PAINTED GYPSUM BOARD. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

370

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

371

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

372

Elevation, looking SE. Concrete and steel bridge with exposed steel ...  

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

Elevation, looking SE. Concrete and steel bridge with exposed steel frame is the central of three bridges crossing Brush Street between east Baltimore and Piquette. The bridge links Old Lake Shore and Michigan Central Main Line on the western side to a New York Central siding on the eastern side - Railroad Overpass, East Milwaukee & Hastings Avenues, Detroit, Wayne County, MI

373

Exposed Ice in the Northern Mid-Latitudes of Mars  

NASA Technical Reports Server (NTRS)

Ice-Rich Layer: Polygonal features with dimensions of approximately 100 meters, bounded by cracks, are commonly observed on the martian northern plains. These features are generally attributed to thermal cracking of ice-rich sediments, in direct analogy to polygons in terrestrial polar regions. We mapped polygons in the northern mid-latitudes (30 to 65 N) using MOC and HiRISE images. Polygons are scattered across the northern plains, with a particular concentration in western Utopia Planitia. This region largely overlaps the Late Amazonian Astapus Colles unit, characterized by polygonal terrain and nested pits consistent with periglacial and thermokarst origins. Bright and Dark Polygonal Cracks: An examination of all MOC images (1997 through 2003) covering the study area demonstrated that, at latitudes of 55 to 65 N, most of the imaged polygons show bright bounding cracks. We interpret these bright cracks as exposed ice. Between 40 and 55 N, most of the imaged polygons show dark bounding cracks. These are interpreted as polygons from which the exposed ice has been removed by sublimation. The long-term stability limit for exposed ice, even in deep cracks, apparently lies near 55 N. Bright and Dark Spots: Many HiRISE and MOC frames showing polygons in the northern plains also show small numbers of bright and dark spots, particularly in western Utopia Planitia. Many of the spots are closely associated with collapse features suggestive of thermokarst. The spots range from tens to approximately 100 meters in diameter. The bright spots are interpreted as exposed ice, due to their prevalence on terrain mapped as ice rich. The dark spots are interpreted as former bright spots, which have darkened as the exposed ice is lost by sublimation. The bright spots may be the martian equivalents of pingos, ice-cored mounds found in periglacial regions on Earth. Terrestrial pingos from which the ice core has melted often collapse to form depressions similar to the martian dark spots. Future Observations: The SHARAD radar should be able to confirm the presence and measure the depth of the interpreted ice-rich layer that forms the Astapus Colles unit. If this layer is confirmed it will strengthen the interpretation of bright polygon cracks and bright spots as exposed ice. HiRISE images of the northern plains are showing unprecedented details of the polygonal cracks. Future HiRISE images that include bright spots, compared to MOC images taken years earlier, will illustrate the temporal stability of the spots. The CRISM spectrometer, with multiple spectral bands and a spatial resolution around 20 meters, should allow mineralogical identification of the material exposed in the polygonal bounding cracks and in the bright spots.

Allen, Carlton C.

2007-01-01

374

Nutritional Status among the Children of Age Group 5-14 Years in Selected Arsenic Exposed and Non-Exposed Areas of Bangladesh  

PubMed Central

Objective: To assess and compare the nutritional status of children aged 5-14 years in arsenic exposed and non- exposed areas. Materials and methods: It was a cross sectional study conducted on 600 children of age 5-14 years from arsenic exposed and non-exposed areas in Bangladesh. Designed questionnaire and check list were used for collection of data. To estimate BMI necessary anthropometric measurements of the studied children were done. Dietary intakes of the study children were assessed using 24-hours recall method. Results: The difference of socio-economic conditions between the children of exposed area and non-exposed area was not significant. On an average the body mass index was found to be significantly (p < 0.01) lower among the children of arsenic exposed area (49%) in comparison to that of children in non-exposed area (38%). Stunting (p < 0.01), wasting (p < 0.05) and underweight (p < 0.05) were significantly higher in exposed group in comparison to non-exposed group. No significant difference of nutrition intake was found between exposed and non-exposed children as well as thin and normal children. Conclusion: In this study children exposed to arsenic contaminated water were found to be suffered from lower nutritional status. PMID:25530768

Rezaul Karim, Mohammad; Ahmad, Sk. Akhtar

2014-01-01

375

Acaricides for controlling ticks on cattle and the problem of acaricide resistance  

Technology Transfer Automated Retrieval System (TEKTRAN)

Toward the end of the nineteenth century a complex of problems related to ticks and tick-borne diseases of cattle created a demand for methods to control ticks and reduce losses of cattle. The discovery and use of arsenical solutions in dipping vats for treating cattle to protect them against ticks ...

376

The AMINO experiment: a laboratory for astrochemistry and astrobiology on the EXPOSE-R facility of the International Space Station  

NASA Astrophysics Data System (ADS)

The study of the evolution of organic matter subjected to space conditions, and more specifically to Solar photons in the vacuum ultraviolet range (120-200 nm) has been undertaken in low-Earth orbit since the 1990s, and implemented on various space platforms. This paper describes a photochemistry experiment called AMINO, conducted during 22 months between 2009 and 2011 on the EXPOSE-R ESA facility, outside the International Space Station. Samples with relevance to astrobiology (connected to comets, carbonaceous meteorites and micrometeorites, the atmosphere of Titan and RNA world hypothesis) have been selected and exposed to space environment. They have been analysed after return to the Earth. This paper is not discussing the results of the experiment, but rather gives a general overview of the project, the details of the hardware used, its configuration and recent developments to enable long-duration exposure of gaseous samples in tight closed cells enabling for the first time to derive quantitative results from gaseous phase samples exposed in space.

Cottin, H.; Saiagh, K.; Guan, Y. Y.; Cloix, M.; Khalaf, D.; Macari, F.; Jérome, M.; Polienor, J.-M.; Bénilan, Y.; Coll, P.; Fray, N.; Gazeau, M.-C.; Raulin, F.; Stalport, F.; Carrasco, N.; Szopa, C.; Bertrand, M.; Chabin, A.; Westall, F.; Vergne, J.; Da Silva, L. A.; Maurel, M.-C.; Chaput, D.; Demets, R.

2015-01-01

377

Outcomes for Drug-Exposed Children Four Years Post-Adoption.  

ERIC Educational Resources Information Center

Prenatally drug-exposed and not drug-exposed children adopted as infants and older children were compared four years after adoption on a range of outcome indicators. Drug-exposed and not drug-exposed children were alike on most outcome indicators, and parental satisfaction with the adoption was high and equivalent for parents of both groups. (TJQ)

Barth, Richard P.; Needell, Barbara

1996-01-01

378

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

379

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

380

Trace metals in occupationally and nonoccupationally exposed individuals.  

PubMed Central

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

1975-01-01

381

Mechanisms of gas precipitation in plasma-exposed tungsten  

SciTech Connect

Precipitation in subsurface bubbles is a key process that governs how hydrogen isotopes migrate through and become trapped within plasma-exposed tungsten. We describe a continuum-scale model of hydrogen diffusion in plasma-exposed materials that includes the effects of precipitation. The model can account for bubble expansion via dislocation loop punching, using an accurate equation of state to determine the internal pressure. This information is used to predict amount of hydrogen trapped by bubbles, as well as the conditions where the bubbles become saturated. In an effort to validate the underlying assumptions, we compare our results with published positron annihilation and thermal desorption spectroscopy data, as well as our own measurements using the tritium plasma experiment (TPE).

R. D. Kolasinski; D. F. Cowgill; D. C. Donovan; M. Shimada

2012-05-01

382

Laser-induced fluorescence of space-exposed polyurethane  

NASA Technical Reports Server (NTRS)

The object of this work was to utilize laser-induced fluorescence technique to characterize several samples of space-exposed polyurethane. These samples were flown on the Long Duration Exposure Facility (LDEF), which was in a shuttle-like orbit for nearly 6 years. Because of our present work to develop laser-induced-fluorescence inspection techniques for polymers, space-exposed samples and controls were lent to us for evaluation. These samples had been attached to the outer surface of LDEF; therefore, they were subjected to thermal cycling, solar ultraviolet radiation, vacuum, and atomic oxygen. It is well documented that atomic oxygen and ultraviolet exposure have detrimental effects on many polymers. This was a unique opportunity to make measurements on material that had been naturally degraded by an unusual environment. During our past work, data have come from artificially degraded samples and generally have demonstrated a correlation between laser-induced fluorescence and tensile strength or elasticity.

Hill, Ralph H., Jr.

1993-01-01

383

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

384

Cancer mortality among workers exposed to zinc chromate paints.  

PubMed

To evaluate the carcinogenicity of chromium compounds among user industries, the proportionate mortality experience of spray painters exposed to zinc chromate primer paints and electroplaters exposed to chromic acid in the aircraft maintenance industry was examined. Compared to the mortality patterns of U.S. white males, no excess of cancer was found in the 48 deaths among electroplaters. Analysis of the 202 deaths among spray painters revealed a significant excess of cancer, primarily of the respiratory tract. The relative increase of respiratory cancer showed a positive gradient with the length of estimated exposure time, and was confined to painters whose interval from first employment to death was at least 20 years. The findings consistent with occupational exposure to chromium compounds, previously shown to be carcinogenic in manufacturing processes, but the effect of other paint constituents, tobacco smoking, or methodologic limitations could not be discounted. PMID:7354410

Dalager, N A; Mason, T J; Fraumeni, J F; Hoover, R; Payne, W W

1980-01-01

385

Hematological Changes in Fingerling Channel Catfish Exposed to Malachite Green  

Microsoft Academic Search

Fingerling channel catfish (Ictalurus punctatus) were exposed to 0.1 mg\\/l malachite green in 40-liter aquariums (fasted fish) and 500-liter troughs (fed fish). In both tests, neutrophilia at 1 and 3 days after treatment was the most drastic hematological change found. Other significant changes (P < 0.05) in the test with fed fish were increases in erythrocyte counts, hemoglobin concentrations, and

John M. Grizzle

1977-01-01

386

Lung Cancer in Railroad Workers Exposed to Diesel Exhaust  

Microsoft Academic Search

Diesel exhaust has been suspected to be a lung carcinogen. The assessment of this lung cancer risk has been limited by lack of studies of exposed workers followed for many years. In this study, we assessed lung cancer mortality in 54,973 U.S. railroad workers between 1959 and 1996 (38 years). By 1959, the U.S. railroad industry had largely converted from

Eric Garshick; Francine Laden; Jaime E. Hart; Bernard Rosner; Thomas J. Smith; Douglas W. Dockery; Frank E. Speizer

2004-01-01

387

Immunotoxicity Monitoring of Hospital Staff Occupationally Exposed to Cytostatic Drugs  

Microsoft Academic Search

The aim of our study was to investigate the immunotoxicity of occupational cytostatic drug exposure, and to assess the possible\\u000a effect of confounding factors, such as age and smoking. In this human study, the immunotoxic effect of antineoplastic drugs\\u000a was investigated among 306 nurses working in oncology chemotherapy units. Results were compared to 98 non-exposed women. The\\u000a immune status of

Anna Biró; Zoltán Fodor; Jen? Major; Anna Tompa

2011-01-01

388

Impact Features and Projectile Residues in Aerogel Exposed on Mir  

Microsoft Academic Search

Approximately 0.63 m2 of SiO2-based aerogel (0.02 g cm?3) was exposed for 18 months on the Mir Station to capture hypervelocity particles from both man-made and natural sources. Optical inspection revealed two major classes of hypervelocity impact features in the aerogel: (1) long, carrot-shaped tracks, well known from laboratory impact experiments, that exhibit a depth- (t) to-diameter (D) relationship of

F. Hörz; M. E. Zolensky; R. P. Bernhard; T. H. See; J. L. Warren

2000-01-01

389

Erythrocytes from ozone-exposed mice exhibit decreased deformability  

SciTech Connect

Injury from short-term exposure to ozone (O/sub 3/) was detected by a simple test of red blood cell (RBC) filterability. This test measures changes in the ability of the RBC to deform--as occurs during passage through small capillaries. Male CD-1 mice were exposed to 1.0, 0.7, or 0.3 ppm O/sub 3/ for 4 hr, and blood samples were obtained by heart puncture. RBCs were suspended in Tris-HCl buffer, pH 7.4, containing 10 mg/dl glucose. After incubation in air for up to 6 hr, the time required for 2 ml RBC suspension to pass through a 3-micron-pore-size polycarbonate filter was determined. A significant increase in the 6-hr filtration time for O/sub 3/-exposed (1.0 ppm) mice over unexposed mice and a lack of protection by vitamin E were shown. The increases in RBC filtration times for O/sub 3/-exposed mice appeared to be dose related. Ozone exposure (1.0 ppm) caused a significant increase in the hematocrit of both vitamin E-deficient and -supplemented mice. Vitamin E supplementation appeared to partially prevent this increase in hematocrit. Measurement of lipid peroxidation by the thiobarbituric acid (TBA) test revealed no detectable levels of TBA-reactive material in RBC from O/sub 3/-exposed mice. These results suggest that measurement of RBC filterability may be feasible as a clinical test for short-term injury from exposure to oxidant gases.

Morgan, D.L.; Dorsey, A.F.; Menzel, D.B.

1985-02-01

390

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

391

Toxicity of lunar dust assessed in inhalation-exposed rats.  

PubMed

Humans will again set foot on the moon. The moon is covered by a layer of fine dust, which can pose a respiratory hazard. We investigated the pulmonary toxicity of lunar dust in rats exposed to 0, 2.1, 6.8, 20.8 and 60.6?mg/m(3) of respirable-size lunar dust for 4?weeks (6?h/day, 5?days/week); the aerosols in the nose-only exposure chambers were generated from a jet-mill ground preparation of a lunar soil collected during the Apollo 14 mission. After 4?weeks of exposure to air or lunar dust, groups of five rats were euthanized 1 day, 1?week, 4?weeks or 13?weeks after the last exposure for assessment of pulmonary toxicity. Biomarkers of toxicity assessed in bronchoalveolar fluids showed concentration-dependent changes; biomarkers that showed treatment effects were total cell and neutrophil counts, total protein concentrations and cellular enzymes (lactate dehydrogenase, glutamyl transferase and aspartate transaminase). No statistically significant differences in these biomarkers were detected between rats exposed to air and those exposed to the two low concentrations of lunar dust. Dose-dependent histopathology, including inflammation, septal thickening, fibrosis and granulomas, in the lung was observed at the two higher exposure concentrations. No lesions were detected in rats exposed to ?6.8?mg/m(3). This 4-week exposure study in rats showed that 6.8?mg/m(3) was the highest no-observable-adverse-effect level (NOAEL). These results will be useful for assessing the health risk to humans of exposure to lunar dust, establishing human exposure limits and guiding the design of dust mitigation systems in lunar landers or habitats. PMID:24102467

Lam, Chiu-wing; Scully, Robert R; Zhang, Ye; Renne, Roger A; Hunter, Robert L; McCluskey, Richard A; Chen, Bean T; Castranova, Vincent; Driscoll, Kevin E; Gardner, Donald E; McClellan, Roger O; Cooper, Bonnie L; McKay, David S; Marshall, Linda; James, John T

2013-10-01

392

Pseudohyphal variations of yeasts exposed to specific space flight parameters.  

PubMed

Phenotypes of Saccharomyces cerevisiae and Rhodotorula rubra exposed to specific parameters of space flight, which were measured both quantitatively and qualitatively, produced variations in pseudohyphal formation. Both the length of the parent and branch psuedohyphal filaments varied according to specific wavelengths and energy levels of UV light exposures when phenotypic isolates were compared with the parent or ground control isolate of each yeast species. PMID:9881461

Volz, P A; Hunter, R L

1998-01-01

393

Biomarkers of genetic damage in humans exposed to benzene  

SciTech Connect

In order to study genetic damage caused by benzene, 44 workers exposed on average to 31 ppm benzene were compared to a control group matched for sex, age, and smoking. Blood samples were processed for the analysis of micronuclei in binucleated lymphocytes, and chromosome rearrangements and aneuploidy by standard methods and fluorescence in situ hybridization. Twenty-three exposed subjects and 22 controls were heterozygous for the red blood cell glycophorin A (GPA) M and N alleles, and were evaluated for the frequency of variant cells (V{sub f}). The GPA V{sub f} was twice as high in the benzene-exposed workers as in controls, with the major being NN (p<0.001). This increase was significantly associated with cumulative lifetime benzene exposure (p=0.032). Thus, benzene causes mutation at the GPA locus in the human bone marrow that are gene-duplicating in nature. Scoring and analysis of micronucleus levels, chromosome aberrations, and chromosomal damage using probes specific for chromosomes 7, 8, and 9 are currently in progress. A variety of metabolic and susceptibility markers are also being measured. These studies should provide a better understanding of the magnitude and nature of genetic damage produced by benzene in humans.

Smith, M.T.; Rothman, N.; Holland, N.T.; Hayes, R.B.; Zhang, L.; Kolachana, P. [Univ. of California, Berkeley, CA (United States); Haas, R. [Haz. Mat. Lab., Berkeley, CA (United States); Li, L.; Yin, S.N. [Chinese Academy Prevent. Med., Beijing (China); Wang, Y.Z. [Shanghai Hygiene/Anti-Epidemic Center, Shanghai (China); Quintana, P.J.E. [Univ. of British Columbia, Vancouver (Canada)

1994-12-31

394

Social play in juvenile rats prenatally exposed to alcohol.  

PubMed

Offspring of rat dams that consumed isocaloric liquid diets containing either 35% or 0% ethanol-derived calories (EDC) from gestation days 6-20 were tested for play-fighting behavior as juveniles. Offspring from a group of dams maintained on standard lab chow and water throughout gestation were also included. Animals were tested in pairs, with offspring from each of the three prenatal treatment conditions (35% EDC, 0% EDC, and lab chow) being paired with another same-sex animal from one of these three prenatal treatment groups. Although play-fighting in juveniles is normally sexually dimorphic, this normal pattern was absent in juveniles prenatally exposed to alcohol. Male alcohol-exposed offspring displayed feminized behavior while female alcohol-exposed offspring showed masculinized behavior. This reversal of the normal sexually dimorphic aspects of play suggests that some of the behavioral disturbances associated with prenatal alcohol exposure may result, in part, from an alcohol-induced disruption of the hormonal environment in which the fetus develops. PMID:3764769

Meyer, L S; Riley, E P

1986-08-01

395

Mechanical properties of MDCK II cells exposed to gold nanorods  

PubMed Central

Summary Background: The impact of gold nanoparticles on cell viability has been extensively studied in the past. Size, shape and surface functionalization including opsonization of gold particles ranging from a few nanometers to hundreds of nanometers are among the most crucial parameters that have been focussed on. Cytoxicity of nanomaterial has been assessed by common cytotoxicity assays targeting enzymatic activity such as LDH, MTT and ECIS. So far, however, less attention has been paid to the mechanical parameters of cells exposed to gold particles, which is an important reporter on the cellular response to external stimuli. Results: Mechanical properties of confluent MDCK II cells exposed to gold nanorods as a function of surface functionalization and concentration have been explored by atomic force microscopy and quartz crystal microbalance measurements in combination with fluorescence and dark-field microscopy. Conclusion: We found that cells exposed to CTAB coated gold nanorods display a concentration-dependent stiffening that cannot be explained by the presence of CTAB alone. The stiffening results presumably from endocytosis of particles removing excess membrane area from the cell’s surface. Another aspect could be the collapse of the plasma membrane on the actin cortex. Particles coated with PEG do not show a significant change in elastic properties. This observation is consistent with QCM measurements that show a considerable drop in frequency upon administration of CTAB coated rods suggesting an increase in acoustic load corresponding to a larger stiffness (storage modulus). PMID:25671166

Pietuch, Anna; Brückner, Bastian Rouven; Schneider, David; Tarantola, Marco; Rosman, Christina; Sönnichsen, Carsten

2015-01-01

396

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

397

Cardiac arrhythmia in refrigerator repairmen exposed to fluorocarbons.  

PubMed Central

A field study of 89 refrigerator repairmen was carried out to ascertain whether occupational exposure to fluorocarbons induces cardiac arrhythmia. The concentrations of fluorocarbons in the breathing zones and the heart activity were recorded simultaneously. Most cooling systems contained FC 12 or FC 22. The highest level recorded in one minute was 14,000 ppm and the highest time weighted level during eight hours was 280 ppm. Two types of arrhythmia were recorded, ectopic beats and sudden bradycardia. A within subject comparison design was applied and the main parameter was the difference in arrhythmia frequencies between exposed and unexposed periods. No appreciable differences between exposed and unexposed periods and no consistent dose effect relations were observed, although subjects in the medium exposure category showed a difference of borderline significance (Wilcoxon's test: p = 0.05, one tailed). The frequencies of arrhythmia when unexposed were somewhat higher than previously reported. Misclassification of the exposure and the possible confounding effect of physical workload and psychological strain may have obscured a causal relation and therefore a minor effect cannot be ruled out. The results do not support the notion that fluorocarbons induce cardiac arrhythmia in occupationally exposed refrigerator repairmen. PMID:2328227

Edling, C; Ohlson, C G; Ljungkvist, G; Oliv, A; Söderholm, B

1990-01-01

398

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

399

Expose-R experiment on effects of open space condition on survivorship in dormant stages of aquatic invertebrates  

NASA Astrophysics Data System (ADS)

Dormancy protects animals and plants in harsh environmental conditions from months up to hundred years. This phenomenon is perspective for space researches especially for interplanetary missions. Direct experiments in open space BYORYSK supported in principle the fact of survivorship of bacteria, fungi spores, seed of plants and crustacean dormant cysts. Even though the rate of survivorship in long-term treatments was low but good enough to conclude that biological invasion even to Mars is a real danger. As soon as the BYORYSK lunch was made of metal the possibility for resting stages to survive under UV treatment in vacuum without some protection was not clear. To test it an ESA and RSA equipment titled EXPOSE-R was applied. The EXPOSE-R facility was an external facility attached to the outside of the Zvezda Service Module in ISS in the end of November 2008. It had glace windows transparent for UV-radiation and possibility to measure temperature, space- and UV-radiation. Among a number of experiments requiring exposure to the open space environment it had a biological launch containing resting stages of terrestrial and aquatic organisms. These stages included dried ephippia of cladoceran Daphnia magna differentiated on size, dormant eggs of ostracode Eucypris ornate, cysts of fair-shrimp Streptocephalus torvicornis ( all from hemi desert Caspian area) and Artemis salina from salt lake Crimean populations. All dormant stages were kept in transparent to UV plastic bags placed in three layers. After about two years of exposing in open space dormant stages of 3 species A. salina, D. magna, S. torvicornis successfully survived at different scales but in second and third layers only . The highest level of survivorship was found in A. salina cysts. In preliminary land experiments that imitated land EXPOSE imitation of outside space station UV and vacuum conditions survivorship in resting eggs of D .magna, S. torvicornis and E. ornate was tested also. The total UV dose of 9,1x10 to the 4th KJ/m2 during this imitation was accomplished with a SOL 2000 sun simulator lamp. The final vacuum value achieved during EST was 10 to the minus 6 Pa. Temperature during the experiment fluctuated in the range 19-25 o C. All the species successfully survived but at higher scale in more deep (protected from direct affect of UV radiation) layers. The experiments gave direct confirmation that dried resting stages of aquatic organisms can be transported to other planets by space vehicles in harsh open space conditions that had both negative (interplanetary quarantine) and positive (outside Earth artificial ecosystem creation) sides. This study was supported by several national RFBR, international RFBR-Japan and travel grant from Malaysia grants.

Alekseev, Victor; Novikova, Nataliya; Levinskikh, Margarita; Sychev, Vladimir; Yusoff, Fatimah; Azuraidi, Osman

2012-07-01

400

Neurologic function among termiticide applicators exposed to chlorpyrifos.  

PubMed Central

Chlorpyrifos is a moderately toxic organophosphate pesticide. Houses and lawns in the United States receive a total of approximately 20 million annual chlorpyrifos treatments, and 82% of U.S. adults have detectable levels of a chlorpyrifos metabolite (3,5, 6-trichloro-2-pyridinol; TCP) in the urine. The U.S. Environmental Protection Agency has estimated that there are 5,000 yearly reported cases of accidental chlorpyrifos poisoning, and approximately one-fourth of these cases exhibit symptoms. Organophosphates affect the nervous system, but there are few epidemiologic data on chlorpyrifos neurotoxicity. We studied neurologic function in 191 current and former termiticide applicators who had an average of 2.4 years applying chlorpyrifos and 2.5 years applying other pesticides, and we compared them to 189 nonexposed controls. The average urinary TCP level for 65 recently exposed applicators was 629.5 microg/L, as compared to 4.5 microg/L for the general U.S. population. The exposed group did not differ significantly from the nonexposed group for any test in the clinical examination. Few significant differences were found in nerve conduction velocity, arm/hand tremor, vibrotactile sensitivity, vision, smell, visual/motor skills, or neurobehavioral skills. The exposed group did not perform as well as the nonexposed group in pegboard turning tests and some postural sway tests. The exposed subjects also reported significantly more symptoms, including memory problems, emotional states, fatigue, and loss of muscle strength; our more quantitative tests may not have been adequate to detect these symptoms. Eight men who reported past chlorpyrifos poisoning had a pattern of low performance on a number of tests, which is consistent with prior reports of chronic effects of organophosphate poisoning. Overall, the lack of exposure effects on the clinical examination was reassuring. The findings for self-reported symptoms raise some concern, as does the finding of low performance for those reporting prior poisoning. Although this was a relatively large study based on a well-defined target population, the workers we studied may not be representative of all exposed workers, and caution should be exercised in generalizing our results. PMID:10753086

Steenland, K; Dick, R B; Howell, R J; Chrislip, D W; Hines, C J; Reid, T M; Lehman, E; Laber, P; Krieg, E F; Knott, C

2000-01-01

401

Exposed Ice in the Northern Mid-Latitudes of Mars  

NASA Astrophysics Data System (ADS)

Ice-Rich Layer: Polygonal features with dimensions of approximately 100 meters, bounded by cracks, are commonly observed on the martian northern plains. These features are generally attributed to thermal cracking of ice-rich sediments, in direct analogy to polygons in terrestrial polar regions [1,2]. We mapped polygons in the northern mid-latitudes (30 to 65 N) using MOC and HiRISE images [3]. Polygons are scattered across the northern plains, with a particular concentration in western Utopia Planitia. This region largely overlaps the Late Amazonian Astapus Colles unit, characterized by polygonal terrain and nested pits consistent with periglacial and thermokarst origins [4]. Bright and Dark Polygonal Cracks: An examination of all MOC images (1997 through 2003) covering the study area demonstrated that, at latitudes of 55 to 65 N, most of the imaged polygons show bright bounding cracks. We interpret these bright cracks as exposed ice. Between 40 and 55 N, most of the imaged polygons show dark bounding cracks [5]. These are interpreted as polygons from which the exposed ice has been removed by sublimation. The long-term stability limit for exposed ice, even in deep cracks, apparently lies near 55 N. Bright and Dark Spots: Many HiRISE and MOC frames showing polygons in the northern plains also show small numbers of bright and dark spots, particularly in western Utopia Planitia. Many of the spots are closely associated with collapse features suggestive of thermokarst. The spots range from tens to approximately 100 meters in diameter. The bright spots are interpreted as exposed ice, due to their prevalence on terrain mapped as ice rich. The dark spots are interpreted as former bright spots, which have darkened as the exposed ice is lost by sublimation. The bright spots may be the martian equivalents of pingos, ice-cored mounds found in periglacial regions on Earth [6,7,8,9, 10]. Terrestrial pingos from which the ice core has melted often collapse to form depressions similar to the martian dark spots. Future Observations: The SHARAD radar should be able to confirm the presence and measure the depth of the interpreted ice-rich layer that forms the Astapus Colles unit. If this layer is confirmed it will strengthen the interpretation of bright polygon cracks and bright spots as exposed ice. HiRISE images of the northern plains are showing unprecedented details of the polygonal cracks. Future HiRISE images that include bright spots, compared to MOC images taken years earlier, will illustrate the temporal stability of the spots. The CRISM spectrometer, with multiple spectral bands and a spatial resolution around 20 meters, should allow mineralogical identification of the material exposed in the polygonal bounding cracks and in the bright spots. References: [1] Seibert N.M. and Kargel J.S. (2001) GRL, 28, 899-902. [2] Mangold N. et al. (2004) JGR, 109, E08001. [3] Kanner L.C. et al. (2004) LPS XXXV, Abstract #1982. [4] Tanaka K.L. et al. (2005) Map 2888, USGS. [5] Kanner L. (2004) Geology Comprehensives Paper, Carleton College (unpublished). [6] Soare R.J. et al. (2005) Icarus, 174, 373-382. [7] Osinski G.R. and Soare R.J. (2007) LPS XXXVIII, Abstract #1609. [8] Ferrand W.H. and Lane M.D. (2007) LPS XXXVIII, Abstract #1972. [9] Dundas C.M. et al. (2007) 7th Intl. Conf. Mars, Abstract #3214. [10] Allen C.C. and Kanner L.C. (2007) 7th Int. Conf. Mars, Abstract #3065.

Allen, C. C.

2007-12-01

402

Presence of Merkel cells in sun-exposed and not sun-exposed skin: a quantitative study  

Microsoft Academic Search

Merkel cells (MCs), the neuroendocrine cells of the skin cannot be identified with certainty using conventional light microscopic staining methods. Using immunoperoxidase microscopy with antibodies specific for cytokeratin 18, which has been established as a marker protein of MCs, we have evaluated the numbers of MCs per mm2 skin in normal and sun-damaged upper arm skin. The sun-exposed skin contained

I. Moll; U. Bladt; E. G. Jung

1990-01-01

403

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

404

Long term health and neurodevelopment in children exposed to antiepileptic drugs before birth  

PubMed Central

Objective: To investigate the frequency of neonatal and later childhood morbidity in children exposed to antiepileptic drugs in utero. Design: Retrospective population based study. Setting: Population of the Grampian region of Scotland. Participants: Mothers taking antiepileptic drugs in pregnancy between 1976 and 2000 were ascertained from hospital obstetric records and 149 (58% of those eligible) took part. They had 293 children whose health and neurodevelopment were assessed. Main outcome measures: Frequencies of neonatal withdrawal, congenital malformations, childhood onset medical problems, developmental delay, and behaviour disorders. Results: Neonatal withdrawal was seen in 20% of those exposed to antiepileptic drugs. Congenital malformations occurred in 14% of exposed pregnancies, compared with 5% of non-exposed sibs, and developmental delay in 24% of exposed children, compared with 11% of non-exposed sibs. After excluding cases with a family history of developmental delay, 19% of exposed children and 3% of non-exposed sibs had developmental delay, 31% of exposed children had either major malformations or developmental delay, 52% of exposed children had facial dysmorphism compared with 25% of those not exposed, 31% of exposed children had childhood medical problems (13% of non-exposed sibs), and 20% had behaviour disorders (5% of non-exposed). Conclusion: Prenatal antiepileptic drug exposure in the setting of maternal epilepsy is associated with developmental delay and later childhood morbidity in addition to congenital malformation. PMID:11950853

Dean, J; Hailey, H; Moore, S; Lloyd, D; Turnpenny, P; Little, J

2002-01-01

405

Modeling assemblies of biological cells exposed to electric fields.  

PubMed

Gap junctions are channels through the cell membrane that electrically connect the interiors of neighboring cells. Most cells are connected by gap junctions, and gaps play an important role in local intercellular communication by allowing for the exchange of certain substances between cells. Gap communication has been observed to change when cells are exposed to electromagnetic (EM) fields. In this work, we examine the behavior of cells connected by gap junctions when exposed to electric fields, in order to better understand the influence of the presence of gap junctions on cell behavior. This may provide insights into the interactions between biological cells and weak, low-frequency EM fields. Specifically, we model gaps in greater detail than is usually the case, and use the finite element method (FEM) to solve the resulting geometrically complex cell models. The responses of gap-connected cell configurations to both dc and time harmonic fields are investigated and compared with those of similarly shaped (equivalent) cells. To further assess the influence of the gap junctions, properties such as gap size, shape, and conductivity are varied. Our findings indicate that simple models, such as equivalent cells, are sufficient for describing the behavior of small gap-connected cell configurations exposed to dc electric fields. With larger configurations, some adjustments to the simple models are necessary to account for the presence of the gaps. The gap junctions complicate the frequency behavior of gap-connected cell assemblies. An equivalent cell exhibits low-pass behavior. Gaps effectively add a bandstop filter in series with the low-pass behavior, thus lowering the relaxation frequency. The characteristics of this bandstop filter change with changes to gap properties. Comparison of the FEM results to those obtained with simple models indicates that more complex models are required to represent gap-connected cells. PMID:9775540

Fear, E C; Stuchly, M A

1998-10-01

406

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

407

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

408

Preliminary results of SMM exposed aluminized Kapton and silvered Teflon  

NASA Technical Reports Server (NTRS)

Early Space Shuttle flights revealed that organic materials, such as those used in thermal control blankets and paints in the payload bay, were adversely affected in the low Earth orbit environment. Examination of eroded surfaces on these early flights and materials experiments performed on subsequent flights led to the conclusion that atomic oxygen present at Shuttle operating altitudes was responsible for surface degradation. The Solar Maximum Mission provided surfaces that had been exposed in real time to atomic oxygen and ultraviolet radiation. Preliminary results of studies of the microscopic surface effects on silvered Teflon and aluminized Kapton used for thermal control on the Solar Maximum Mission are presented.

Santos-Mason, B.

1985-01-01

409

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

410

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

411

Maximally exposed offsite individual location determination for NESHAPS compliance  

SciTech Connect

The Environmental Protection Agency (EPA) requires the use of the computer program CAP88 for demonstrating compliance with the National Emission Standard for Hazardous Air Pollutants (NESHAPS.) One of the inputs required for CAP88 is the location of the maximally exposed individual (MEI) by sector and distance. Distances to the MEI have been determined for 15 different potential release locations at SRS. These locations were compared with previous work and differences were analyzed. Additionally, SREL Conference Center was included as a potential offsite location since in the future it may be used as a dormitory. Worst sectors were then determined based on the distances.

Simpkins, A.A.

2000-03-13

412

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 < 0.01) increase in mean percent tail DNA, frequency of CA, and MN in PBL as well as in BEC as compared to controls. Pb in ambient air and B-Pb concentrations were found to be significantly higher (P < 0.01). The hematocrit, hemoglobin, and red blood cell values were significantly lowered in Pb-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

413

Oxidative stress in songbirds exposed to dietary methylmercury.  

PubMed

Long-term, sublethal methylmercury exposure can cause reproductive depression, immune suppression, endocrine disruption and other problems in birds. We used two biomarkers to detect oxidative stress in livers of zebra finches (Taeniopygia guttata) developmentally exposed to sublethal levels of dietary methylmercury (0.0, 0.3, 0.6, 1.2, or 2.4 ?g/g wet weight in diet). Our findings indicate that young adult finches exposed to environmentally relevant concentrations of mercury in ovo and through their diets, exhibited oxidative stress in their livers. We measured the ratio of the antioxidant glutathione in its reduced form (GSH) versus its oxidized form (GSSG) and the activity of the superoxide dismutase (SOD) enzyme suite. Blood total mercury served as a proxy for liver mercury concentration, and was on average 8.4 times the dietary dose (e.g., birds consuming 0.6 ?g/g had blood mercury levels of ~5 ?g/g on a wet weight basis). Consistent with what is known from large, aquatic bird species, there was a significant, negative relationship between GSH/GSSG ratios and tissue mercury concentrations, which is indicative of oxidative stress. This relationship was driven by a significant increase in the oxidized glutathione in the livers of birds with higher blood mercury levels. SOD activity was also found to have a significant, negative relationship with blood mercury. PMID:25519780

Henry, Katie A; Cristol, Daniel A; Varian-Ramos, Claire W; Bradley, Eric L

2015-04-01

414

Urinary nickel and prolactin in workers exposed to urban stressors.  

PubMed

The aim of our study is to verify whether the exposure to low Ni doses in urban air may have some effects on the prolactin values of outdoor workers exposed to urban pollutants. 334 workers have been included in the study and divided on the basis of gender, job, age, length of service and smoking habits. Each worker underwent urinary Ni and prolactin sampling. The t-test for independent samples, the Mann-Whitney U test for two mode variables (gender, smoking habit), the univariate ANOVA test and the Kruskal Wallis test for the variables in more than two modes (age, length of service and job duties) were performed on the total sample. Pearson's correlation coefficient (p two-tailed) among the parameters was evaluated both in the total sample and after the stratification by gender, smoking habit and job. Multiple linear regression was performed after taking account of the major confounding factors on the total sample and on the subcategories. The statistical tests showed a significant correlation between urinary Ni and prolactin both in the total sample and in the subcategories. We believe that the occupational exposure to low doses of Ni present in urban pollution may influence the prolactin values in exposed workers. PMID:24081300

Caciari, Tiziana; Rosati, Maria Valeria; Di Giorgio, Valeria; Casale, Teodorico; Pimpinella, Benedetta; Scala, Barbara; Giubilati, Roberto; Capozzella, Assunta; Tomei, Gianfranco; Tomei, Francesco

2013-10-01

415

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

416

Follow-up of infants prenatally exposed to cocaine.  

PubMed

Maternal cocaine use during pregnancy continues to be of great concern for health care professionals. Research in this area has increased as investigators examine the effects of prenatal cocaine exposure in the infant/young child. This paper will critically review the literature, identify the primary care needs of infants and young children with a known history of prenatal cocaine exposure, and present guidelines for the primary care practitioner to monitor the infant's physiologic and developmental sequelae during the first 3 years of life. Findings in the literature demonstrate inconsistencies in regard to the physiologic and developmental outcomes of infants/young children prenatally exposed to cocaine. Further research is warranted, as it is evident from studies that not all investigators are controlling for confounding variables such as poly-drug use, which is necessary in isolating cocaine's effects. Subtle effects, however, have been reported from well-controlled studies and, thus, particular attention needs to be paid to early identification and interventions by primary care practitioners to prevent negative health outcomes. The guidelines proposed assist the practitioner with a thorough and focused approach to assessing the physiologic and developmental effects that are currently known to occur in the infant/young child prenatally exposed to cocaine. PMID:16295162

Schiller, Cassandra; Allen, Pat Jackson

2005-01-01

417

Risk of spontaneous abortion in workers exposed to toluene.  

PubMed Central

Rates of spontaneous abortions were determined using a reproductive questionnaire administered by personal interview to 55 married women with 105 pregnancies. They were employed in an audio speaker factory and were exposed to high concentrations of toluene (mean 88, range 50-150 ppm). These rates of spontaneous abortion were compared with those among 31 women (68 pregnancies) who worked in other departments in the same factory and had little or no exposure to toluene (0-25 ppm), as well as with a community control group of women who underwent routine antenatal and postnatal care at public maternal health clinics (190 women with 444 pregnancies). Significantly higher rates for spontaneous abortions were noted in the group with high exposure to toluene (12.4 per 100 pregnancies) compared with those in the internal control group (2.9 per 100 pregnancies) and in the external control group (4.5 per 100 pregnancies). Among the exposed women, significant differences were also noted in the rates of spontaneous abortion before employment (2.9 per 100 pregnancies) and after employment in the factory (12.6 per 100 pregnancies). Almost all the women were nonsmokers and did not drink; other known risk factors such as maternal age at pregnancy, order of gravidity, and race were not likely to explain the results. Thus, specific exposure to toluene seems to be associated with a risk of foetal loss. PMID:1463682

Ng, T P; Foo, S C; Yoong, T

1992-01-01

418

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

419

Primary stress responses in Arabidopsis thaliana exposed to gamma radiation.  

PubMed

As the environment is inevitably exposed to ionizing radiation from natural and anthropogenic sources, it is important to evaluate gamma radiation induced stress responses in plants. The objective of this research is therefore to investigate radiation effects in Arabidopsis thaliana on individual and subcellular level by exposing 2-weeks-old seedlings for 7 days to total doses of 3.9 Gy, 6.7 Gy, 14.8 Gy and 58.8 Gy and evaluating growth, photosynthesis, chlorophyll a, chlorophyll b and carotenoid concentrations and antioxidative enzyme capacities. While the capacity of photosystem II (PSII measured as Fv/Fm) remained intact, plants started optimizing their photosynthetic process at the lower radiation doses by increasing the PSII efficiency (?PSII) and the maximal electron transport rate (ETRmax) and by decreasing the non-photochemical quenching (NPQ). At the highest radiation dose, photosynthetic parameters resembled those of control conditions. On subcellular level, roots showed increased superoxide dismutase (SOD) and ascorbate peroxidase (APX) capacities under gamma irradiation but catalase (CAT), syringaldazine peroxidase (SPX) and guaiacol peroxidase (GPX) activities, on the other hand, decreased. In the leaves no alterations were observed in SOD, CAT and SPX capacities, but GPX was highly affected. Based on these results it seems that roots are more sensitive for oxidative stress under gamma radiation exposure than leaves. PMID:24333636

Vanhoudt, Nathalie; Horemans, Nele; Wannijn, Jean; Nauts, Robin; Van Hees, May; Vandenhove, Hildegarde

2014-03-01

420

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

421

Gender-related behavior in women exposed prenatally to diethylstilbestrol.  

PubMed Central

Accumulating evidence in experimental animals over the past three decades suggests that mammalian brain development and differentiation of the central nervous system are influenced by perinatal exposure to sex hormones. Hence, changes in human behavioral patterns may be associated with prenatal exposure to estrogenic substances such as diethylstilbestrol (DES). This paper reviews relevant studies from a series of laboratories and finds that no clear-cut differences can be demonstrated to date between unexposed and DES-exposed women in gender-related behavior, although the physical and psychological impact of the problems associated with exposure to DES are well documented. If both prenatal and postnatal influences such as social, economic, and environmental factors are taken into consideration, individual variation is more apparent than differences in gender-related behavior between unexposed and DES-exposed women. In summary, gender-related behavior is determined by a complex array of interacting factors, and prenatal influences are only one of many developmental events. More studies are needed using larger populations with carefully controlled selection criteria to suggest a direct role of prenatal DES exposure on subsequent gender-related behavior. Images p208-a PMID:8404755

Newbold, R R

1993-01-01

422

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

423

Error-Related Negativities During Spelling Judgments Expose Orthographic Knowledge  

PubMed Central

In two experiments, we demonstrate that error-related negativities (ERNs) recorded during spelling decisions can expose individual differences in lexical knowledge. The first experiment found that the ERN was elicited during spelling decisions and that its magnitude was correlated with independent measures of subjects’ spelling knowledge. In the second experiment, we manipulated the phonology of misspelled stimuli and observed that ERN magnitudes were larger when misspelled words altered the phonology of their correctly spelled counterparts than when they preserved it. Thus, when an error is made in a decision about spelling, the brain processes indexed by the ERN reflect both phonological and orthographic input to the decision process. In both experiments, ERN effect sizes were correlated with assessments of lexical knowledge and reading, including offline spelling ability and spelling-mediated vocabulary knowledge. These results affirm the interdependent nature of orthographic, semantic, and phonological knowledge components while showing that spelling knowledge uniquely influences the ERN during spelling decisions. Finally, the study demonstrates the value of ERNs in exposing individual differences in lexical knowledge. PMID:24389506

Harris, Lindsay N.; Perfetti, Charles A.; Rickles, Benjamin

2014-01-01

424

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

425

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

426

Thyroid neoplasia in Marshall Islanders exposed to nuclear fallout  

SciTech Connect

We studied the risk of thyroid neoplasia in Marshall Islanders exposed to radioiodines in nuclear fallout from the 1954 BRAVO thermonuclear test. We screened 7266 Marshall Islanders for thyroid nodules; the islanders were from 14 atolls, including several southern atolls, which were the source of the best available unexposed comparison group. Using a retrospective cohort design, we determined the prevalence of thyroid nodularity in a subgroup of 2273 persons who were alive in 1954 and who therefore were potentially exposed to fallout from the BRAVO test. For those 12 atolls previously thought to be unexposed to fallout, the prevalence of thyroid nodules ranged from 0.9% to 10.6%. Using the distance of each atoll from the test site as a proxy for the radiation dose to the thyroid gland, a weighted linear regression showed an inverse linear relationship between distance and the age-adjusted prevalence of thyroid nodules. Distance was the strongest single predictor in logistic regression analysis. A new absolute risk estimate was calculated to be 1100 excess cases/Gy/y/1 X 10(6) persons (11.0 excess cases/rad/y/1 million persons), 33% higher than previous estimates. We conclude that an excess of thyroid nodules was not limited only to the two northern atolls but extended throughout the northern atolls; this suggests a linear dose-response relationship.

Hamilton, T.E.; van Belle, G.; LoGerfo, J.P.

1987-08-07

427

Asbestos-exposed populations: prevention, care, and compensation  

SciTech Connect

In Israel, the prevention and care of asbestos-associated diseases with latency periods of one to four decades (asbestosis, mesothelioma, increased frequency of cancer of the lung and other sites) are not satisfactory, and new national policies are required. Such policies have three major goals: (a) elimination or reduction of exposure to asbestos dust; (b) measures to promote cessation or drastic reduction of cigarette smoking among those currently or formerly exposed; and (c) equitable compensation for the consequences of past exposures. The practical elements of a program to achieve these three goals include (a) exposure standards and control technology; (b) identification of sources, routes, and levels of exposure and groups at risk; (c) compensation and job security; (d) medical monitoring and follow-up; (e) smoking cessation; (f) selective substitution of other substances for asbestos; and (g) establishment of a panel for policy supervision and the overseeing of compensation programs. Delay in implementation risks higher death rates for asbestosis and cancer among previously exposed workers, greater exposure among current workers, loss of experienced workers from the work force, and unnecessary hardship for families not adequately compensated.

Richter, E.D.; Tulchinsky, T.; Goldsmith, J.R.; Yaffe, Y.

1984-05-01

428

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

429

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

430

Characteristics and outcomes of drug-exposed and non drug-exposed children in kinship and non-relative foster care  

Microsoft Academic Search

This study describes the characteristics and outcomes of drug-exposed and non drug-exposed children in kinship and non-relative foster care. Outcomes included educational performance, emotional development, and problem behavior. Children were an average of 7.9 years old at the time of the study and were either 1.(a) non drug-exposed children placed with kin (n = 139),2.(b) drugexposed children placed with kin

Devon Brooks; Richard P. Barth

1998-01-01

431

Guidelines for Pregnant Women Who Have Been Exposed to Anthrax but Do Not Have Symptoms  

MedlinePLUS

... Who Have Been Exposed to Anthrax But Do Not Have Symptoms Recommend on Facebook Tweet Share Compartir ... have been exposed to anthrax, but who do not have symptoms of anthrax disease. For CDC guidelines ...

432

Biochemical Adaptations in Pseudomonas fluorescens Exposed to Nitric Oxide, an Endogenous Antibacterial Agent  

E-print Network

Biochemical Adaptations in Pseudomonas fluorescens Exposed to Nitric Oxide, an Endogenous supérieures Title of Thesis Titre de la thèse BIOCHEMICAL ADAPTATIONS IN PSEUDOMONAS FLUORESCENS EXPOSED. fluorescens engineers an elaborate metabolic network to generate ATP whilst withstanding the injurious effects

Appanna, Vasu

433

The Chernobyl Accident and Cognitive Functioning: A Study of Norwegian Adolescents Exposed In Utero  

Microsoft Academic Search

The results of investigations on the cognitive outcomes of adolescents exposed prenatally to radiation from Chernobyl are inconsistent. In 2005 through 2006, we assessed individuals exposed prenatally (N = 84) and controls (N = 94) using a broad neuropsychological test battery. Neuropsychological performance was significantly weaker in the 84 adolescents exposed prenatally compared to the 94 controls on measures of

Kristin Sverdvik Heiervang; Sarnoff Mednick; Kjetil Sundet

2010-01-01

434

Marital Relationship and Its Associated Factors in Veterans Exposed to High Dose Chemical Warfare Agents  

Microsoft Academic Search

Objective: The aim of this study was to determine the associates of marital relationship in mustard exposed veterans. Materials and Methods: Two hundred ninety two married Iranian mustard exposed veterans, who had been exposed to single high dose mustard gas in Iraq-Iran war, were assessed for marital adjustment with Revised Dyadic Adjustment Scale (RDAS). Census sampling was done. The patients'

Shervin Assari; Mohammad Reza Soroush; Hamid Reza; Khoddami Vishteh; Batol Mousavi; Mostafa Ghanei; Sima Karbalaeiesmaeili

2008-01-01

435

Whole-Cell Immobilization Using Cell Surface-Exposed Cellulose-Binding Domain  

E-print Network

Whole-Cell Immobilization Using Cell Surface-Exposed Cellulose-Binding Domain Aijun A. Wang,, Ashok coli with surface-exposed cellulose-binding domain (CBD) to cellulosic materials was investigated supports. Cells with surface-exposed CBD bound specifically and tightly to cellulose supports at a wide

Chen, Wilfred

436

Characterization of oxidized Al-1100 exposed to hygrothermic environments  

NASA Astrophysics Data System (ADS)

The oxides formed on Al-1100 by chromate conversion, chronic acid and sulfuric acid anodizing were characterized, prior to (as previously published) and after exposure to hygrothermic environments, by spectroscopic methods. The suitability of adhesive bonding and durability accomplished with silicone rubber were evaluated by shear bond strength and by the locus of failure using single lap joints and SEM/EDAX, respectively. Results from Auger/ESCA and IR have shown that in the exposed oxide layers the oxygen concentration increased due to water absorption, leading to transformation from oxide to hydroxide. In the case of chromic acid anodizing, which gave the optimal bonding performance, the reverse occurred regarding oxygen concentration while IR results showed water absorption.

Dodiuk, H.; Yaniv, A. E.; Fin, N.

1987-09-01

437

Ion irradiated graphite exposed to fusion-relevant deuterium plasma  

NASA Astrophysics Data System (ADS)

Graphite samples were irradiated with 5 MeV carbon ions to simulate the damage caused by collision cascades from neutron irradiation in a fusion environment. The ion irradiated graphite samples were then exposed to a deuterium plasma in the linear plasma device, MAGPIE, for a total ion fluence of ?1 × 1024 ions m-2. Raman and near edge X-ray absorption fine structure (NEXAFS) spectroscopy were used to characterize modifications to the graphitic structure. Ion irradiation was observed to decrease the graphitic content and induce disorder in the graphite. Subsequent plasma exposure decreased the graphitic content further. Structural and surface chemistry changes were observed to be greatest for the sample irradiated with the greatest fluence of MeV ions. D retention was measured using elastic recoil detection analysis and showed that ion irradiation increased the amount of retained deuterium in graphite by a factor of four.

Deslandes, Alec; Guenette, Mathew C.; Corr, Cormac S.; Karatchevtseva, Inna; Thomsen, Lars; Ionescu, Mihail; Lumpkin, Gregory R.; Riley, Daniel P.

2014-12-01

438

Pulmonary impairment in workers exposed to silicon carbide.  

PubMed Central

Two hundred and sixty seven workers employed in the manufacture of silicon carbide (SiC) were examined to determine the effects of exposure to contaminants (SiC, quartz, and SO2) in the workplace on pulmonary function. No exposure concentrations exceeded the current permissible limits. Ten subjects (3.7%) showed rounded opacities (profusion greater than or equal to 1/0). Two subjects employed only in the final stages of the production process and not exposed to crystalline silica showed opacities (profusion q1/0 and q2/1) on x ray film suggesting a role of SiC in the genesis of interstitial lung disease. Chest abnormalities on x ray film were correlated with cumulative exposure to dust and pulmonary function was affected by cumulative dust exposure, profusion of opacities, and smoking. It is concluded that the current standards do not provide adequate protection against pneumoconiosis and chronic pulmonary disease in this industry. PMID:1637708

Marcer, G; Bernardi, G; Bartolucci, G B; Mastrangelo, G; Belluco, U; Camposampiero, A; Saia, B

1992-01-01

439

Solderability of environmentally exposed Sn-plated surfaces  

SciTech Connect

Solderability of Class II environmentally exposed Ni-Sn plated Cu substrates was evaluated with 60Sn-40Pb solder. Tin thickness were 10, 50, and 150 {mu}in. The 10 {mu}in. plating gave the smallest solder meniscus rise. A general decrease in contact angle, or increase in wettability, was observed with increasing Sn plating. The environmental exposures retarded the wetting rate and increased the time to maximum wetting, particularly with only 10 {mu}in. of Sn. Although the solderability of the 50 and 150 {mu}in. surfaces were not significantly affected by the test conditions, an intermediate plating thickness of 100 {mu}in. is preferred for processing flexibility. 13 refs., 6 figs., 1 tab.

Hosking, F.M.; Sorensen, N.R.

1990-01-01

440

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

441

Construction of exposed indecomposable positive linear maps between matrix algebras  

E-print Network

We construct a large class of indecomposable positive linear maps from the $2\\times 2$ matrix algebra into the $4\\times 4$ matrix algebra, which generate exposed extreme rays of the convex cone of all positive maps. We show that extreme points of the dual faces for separable states arising from these maps are parametrized by the Riemann sphere, and the convex hulls of the extreme points arising from a circle parallel to the equator have the exactly same properties with the convex hull of the trigonometric moment curve studied from combinatorial topology. Any interior points of the dual faces are $2\\otimes 4$ boundary separable states with full ranks. We exhibit concrete examples of such states.

Kil-Chan Ha; Seung-Hyeok Kye

2014-10-21

442

Changes on radiographs of wives of workers exposed to asbestos  

SciTech Connect

Between January and March 1986, 117 wives of insulation workers exposed to asbestos were screened by means of chest radiography, pulmonary function testing, and a detailed questionnaire. The final study group included 93 women over 40 years of age. Eighteen of these (19.4%) demonstrated pleural changes consistent with asbestos exposure, including pleural plaque (88.9%), diaphragm plaque (27.8%), pleural calcification (16.6%), and diffuse pleural thickening (5.5%). In statistical correlation between the groups with normal and abnormal radiographs, the only factor that proved significant was the year of first exposure (the duration of the latent period). Finally, radiographs of the husbands were compared for 17 of the 18 wives with radiographic abnormalities. Fourteen of the husbands (82%) demonstrated more severe radiographic changes than their wives.

Sider, L.; Holland, E.A.; Davis, T.M. Jr.; Cugell, D.W.

1987-09-01

443

Thioethers in urine of sterilization personnel exposed to ethylene oxide.  

PubMed

Biological monitoring of exposure to ethylene oxide (EO) was carried out in 31 hospital workers in the sterilization facilities of five hospitals. The excretion of total thioethers was determined in the urine of sterilization workers. An occupational nonexposed group served as a control (n = 31). The air EO level was not monitored routinely, however, peak concentrations of EO up to 200 p.p.m. were detected mainly when the sterilization chambers were open. Our results show a significant difference in urinary thioether excretion between the exposed and control groups (P less than 0.001). Sterilization workers seem to absorb significant quantities of EO. We feel that other alternative and more sensitive methods for detecting thioether metabolites of EO should be carried out to confirm our results. PMID:1639877

Burgaz, S; Rezanko, R; Kara, S; Karakaya, A E

1992-06-01

444

Biological monitoring of a worker acutely exposed to MBOCA  

SciTech Connect

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 from a MBOCA and polymer mixing machine. The subsequent environmental and medical evaluation of this episode included serial urinary MBOCA samples from the worker over a 2 week period to allow the calculation of a biological half-life for this compound. This worker experienced a very high dose of MBOCA as judged by his urinary MBOCA levels (peak value of 1,700 ppb 4 hours after exposure). There were no acute symptoms or other laboratory abnormalities noted. The kinetic evaluation resulted in a biological half-life for MBOCA in urine of approximately 23 hours. Assuming a one-compartment model, approximately 94% of an initial MBOCA dose will be eliminated within four days. This is the first report of kinetic analysis on urinary MBOCA excretion in humans. This information suggests that biological monitoring of the urine MBOCA concentrations in exposed workers may miss peak levels following an acute exposure unless the analyses of the urinary MBOCA are performed in a timely fashion. Recommendations to the company included: (1) installation of a warning system or lock-out device on the mixing machine to prevent the opening of the MBOCA hose prior to the release of pressure; and (2) annual medical surveillance of this individual for bladder cancer with urinalysis and urine cytology.

Osorio, A.M.; Clapp, D.; Ward, E.; Wilson, H.K.; Cocker, J. (NIOSH, DSHEFS, Cincinnati, OH (USA))

1990-01-01

445

Water relations of differentially irrigated cotton exposed to ozone  

SciTech Connect

The field study was conducted to test the hypothesis that plants chronically exposed to O{sub 3} may be more susceptible to drought because O{sub 3} typically inhibits root growth and increases shoot-root ratios in plants. Cotton was grown in open-top chambers on Hanford coarse sandy loam in Riverside, CA. Plants were grown under three irrigation regimes: Optimum water for lint production (OW), suboptimum or moderate drought stress (SO), and severely drought stressed (SS) and were exposed to seasonal 12 h (0800-2000) O{sub 3} centrations of 0.015, 0.074, 0.094, or 0.111/microLL. Leaf xylem pressure potentials Psi(sub 1) and soil water content Theta(sub v) were measured weekly from June to October. Mean seasonal Psi(sub 1) increased from -1.89 MPa to -1.72 MPa in low to high O{sub 3} treatments, averaged across soil water regimes. Ozone had no effect on seasonal water use of cotton, but water use efficiency was significantly reduced by O{sub 3} in OW and SO, but not in SS treatments. Drought-stressed plants extracted proportionally greater amounts of water from deeper in the soil profile than OW cotton, and O{sub 3} had no apparent effect on this redistribution of roots in the soil. Since O{sub 3} had no apparent effect on the ability of drought-stressed cotton to maintain Psi(sub 1) and to increase root growth relative to shoot growth, this suggests that O{sub 3} may have little or no effect on the potential of cotton to adapt to or tolerate drought.

Temple, P.J.

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