Nitric oxide heme interactions in nitrophorin from Cimex lectularius

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Christmann, R.; Auerbach, H., E-mail: auerbach@physik.uni-kl.de [University of Kaiserslautern, Department of Physics (Germany); Berry, R. E.; Walker, F. A. [The University of Arizona, Department of Chemistry and Biochemistry (United States); Schünemann, V. [University of Kaiserslautern, Department of Physics (Germany)

2016-12-15

The nitrophorin from the bedbug Cimex lectularius (cNP) is a nitric oxide (NO) carrying protein. Like the nitrophorins (rNPs) from the kissing bug Rhodnius prolixus, cNP forms a stable heme Fe(III)-NO complex, where the NO can be stored reversibly for a long period of time. In both cases, the NPs are found in the salivary glands of blood-sucking bugs. The insects use the nitrophorins to transport the NO to the victim’s tissues, resulting in vasodilation and reduced blood coagulation. However, the structure of cNP is significantly different to those of the rNPs from Rhodnius prolixus. Furthermore, the cNP can bind a second NO molecule to the proximal heme cysteine when present at higher concentrations. High field Mössbauer spectroscopy on {sup 57}Fe enriched cNP complexed with NO shows reduction of the heme iron and formation of a ferrous nitric oxide (Fe(II)-NO) complex. Density functional theory calculations reproduce the experimental Mössbauer parameters and confirm this observation.

Chronic Prurigo: An Unusual Presentation of Hodgkin Lymphoma

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Shireen Dumont

2018-05-01

Full Text Available Background: Prurigo nodularis is a condition of unknown origin defined by papulonodular eruption and intense pruritus. Hodgkin lymphoma often presents nonspecific initial symptoms. An association between systemic malignancy and cutaneous manifestations has long been documented. We report a case of prurigo nodularis as a first presentation of Hodgkin lymphoma. Case: A 35-year-old woman presented with a 2-year history of pruritus. Previously diagnosed with bedbugs, the pruritus persisted even after insect eradication, with the appearance of papulonodular lesions consistent with chronic prurigo. The pruritus and the pain were refractory to all treatments. She had no past medical history or clinical, radiological, or laboratory findings. A lymphadenopathy was revealed 2 years after onset of the symptoms. Lymph node biopsy showed a nodular sclerosis Hodgkin lymphoma. The patient was initiated on chemotherapy and the skin lesions decreased. Conclusion: This case report of chronic prurigo as the first manifestation of a systemic malignancy reminds us of the importance of a systematic diagnostic approach to this kind of patients initially and throughout time, especially if the symptoms do not respond to treatment. Our case may question the role of imaging examinations in the management and follow-up of a persistent prurigo nodularis.

Riboflavin Provisioning Underlies Wolbachia’s Fitness Contribution to Its Insect Host

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Moriyama, Minoru; Nikoh, Naruo; Hosokawa, Takahiro

2015-01-01

ABSTRACT Endosymbiotic bacteria of the genus Wolbachia represent the most successful symbiotic bacteria in the terrestrial ecosystem. The success of Wolbachia has been ascribed to its remarkable phenotypic effects on host reproduction, such as cytoplasmic incompatibility, whereby maternally inherited bacteria can spread in their host populations at the expense of their host’s fitness. Meanwhile, recent theoretical as well as empirical studies have unveiled that weak and/or conditional positive fitness effects may significantly facilitate invasion and spread of Wolbachia infections in host populations. Here, we report a previously unrecognized nutritional aspect, the provision of riboflavin (vitamin B2), that potentially underpins the Wolbachia-mediated fitness benefit to insect hosts. A comparative genomic survey for synthetic capability of B vitamins revealed that only the synthesis pathway for riboflavin is highly conserved among diverse insect-associated Wolbachia strains, while the synthesis pathways for other B vitamins were either incomplete or absent. Molecular phylogenetic and genomic analyses of riboflavin synthesis genes from diverse Wolbachia strains revealed that, in general, their phylogenetic relationships are concordant with Wolbachia’s genomic phylogeny, suggesting that the riboflavin synthesis genes have been stably maintained in the course of Wolbachia evolution. In rearing experiments with bedbugs (Cimex lectularius) on blood meals in which B vitamin contents were manipulated, we demonstrated that Wolbachia’s riboflavin provisioning significantly contributes to growth, survival, and reproduction of the insect host. These results provide a physiological basis upon which Wolbachia-mediated positive fitness consequences are manifested and shed new light on the ecological and evolutionary relevance of Wolbachia infections. PMID:26556278

Risky health environments: women sex workers' struggles to find safe, secure and non-exploitative housing in Canada's poorest postal code.

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Lazarus, L; Chettiar, J; Deering, K; Nabess, R; Shannon, K

2011-12-01

This study explored low-income and transitional housing environments of women sex workers and their role in shaping agency and power in negotiating safety and sexual risk reduction in Vancouver, Canada. A series of 12 focus group discussions were conducted with 73 women currently involved in street-based sex work. These women were purposively sampled for a range of experiences living in low-income housing environments, including homeless shelters, transitional housing, and co-ed and women-only single-room occupancy (SRO) hotels. Drawing on the risk environment framework and theoretical constructs of gender, agency and power, analyses demonstrate that women continue to be vulnerable to violence and sexual and economic exploitation and have reduced ability to negotiate risk reduction resulting from the physical, structural and social environments of current dominant male-centred housing models. Within the physical environment, women described inhabitable housing conditions in SROs with infestations of bedbugs and rats, leading women to even more transitional housing options such as shelters and couch-surfing. In many cases, this resulted in their economic exploitation and increased sexual risk. Within the structural environment, enforcement of curfews and guest policies forced women to accept risky clients to meet curfew, or work outdoors where their ability to negotiate safety and condom use were limited. Certain policies promoted women's agency and mitigated their ability to reduce risks when selling sex. These included flexible curfews and being able to bring clients home. The social environments of co-ed single-room occupancy hotels resulted in repeated violence by male residents and discrimination by male building staff. Women-only shelters and SROs facilitated 'enabling environments' where women developed support systems with other working women that resulted in safer work practices. The narratives expressed in this study reveal the critical need for public

Surveillance study of vector species on board passenger ships, Risk factors related to infestations

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Hatzoglou Chrissi

2008-03-01

Full Text Available Abstract Background Passenger ships provide conditions suitable for the survival and growth of pest populations. Arthropods and rodents can gain access directly from the ships' open spaces, can be carried in shiploads, or can be found on humans or animals as ectoparasites. Vectors on board ships may contaminate stored foods, transmit illness on board, or, introduce diseases in new areas. Pest species, ship areas facilitating infestations, and different risk factors related to infestations were identified in 21 ferries. Methods 486 traps for insects and rodents were placed in 21 ferries. Archives of Public Health Authorities were reviewed to identify complaints regarding the presence of pest species on board ferries from 1994 to 2004. A detail questionnaire was used to collect data on ship characteristics and pest control practices. Results Eighteen ferries were infested with flies (85.7%, 11 with cockroaches (52.3%, three with bedbugs, and one with fleas. Other species had been found on board were ants, spiders, butterflies, beetles, and a lizard. A total of 431 Blattella germanica species were captured in 28 (9.96% traps, and 84.2% of them were nymphs. One ship was highly infested. Cockroach infestation was negatively associated with ferries in which Hazard Analysis Critical Control Point system was applied to ensure food safety on board (Relative Risk, RR = 0.23, p = 0.03, and positively associated with ferries in which cockroaches were observed by crew (RR = 4.09, p = 0.007, no cockroach monitoring log was kept (RR = 5.00, p = 0.02, and pesticide sprays for domestic use were applied by crew (RR = 4.00, p = 0.05. Cockroach infested ships had higher age (p = 0.03. Neither rats nor mice were found on any ship, but three ferries had been infested with a rodent in the past. Conclusion Integrated pest control programs should include continuing monitoring for a variety of pest species in different ship locations; pest control measures should be more

RISKY HEALTH ENVIRONMENTS:WOMEN SEX WORKERS’ STRUGGLES TO FIND SAFE, SECURE AND NON-EXPLOITATIVE HOUSING IN CANADA’S POOREST POSTAL CODE

Science.gov (United States)

Lazarus, L; Chettiar, J; Deering, K; Nabess, R; Shannon, K

2011-01-01

This study explored low-income and transitional housing environments of women sex workers and their role in shaping agency and power in negotiating safety and sexual risk reduction in Vancouver, Canada. A series of 12 focus group discussions were conducted with 73 women currently involved in street-based sex work. These women were purposively sampled for a range of experiences living in low-income housing environments, including homeless shelters, transitional housing, and co-ed and women-only single room occupancy (SRO) hotels. Drawing on the risk environment framework and theoretical constructs of gender, agency and power, analyses demonstrate that women continue to be vulnerable to violence and sexual and economic exploitation and have reduced ability to negotiate risk reduction resulting from the physical, structural and social environments of current dominant male-centred housing models. Within the physical environment, women described inhabitable housing conditions in SROs with infestations of bedbugs and rats, leading women to even more transitional housing options such as shelters and couch-surfing. In many cases, this resulted in their economic exploitation and increased sexual risk. Within the structural environment, enforcement of curfews and guest policies forced women to accept risky clients to meet curfew, or work outdoors where their ability to negotiate safety and condom use were limited. Certain policies promoted women’s agency and mitigated their ability to reduce risks when selling sex. These included flexible curfews and being able to bring clients home. The social environments of co-ed single-room occupancy hotels resulted in repeated violence by male residents and discrimination by male building staff. Women-only shelters and SROs facilitated ‘enabling environments’ where women developed support systems with other working women that resulted in safer work practices. The narratives expressed in this study reveal the critical need for

Biological characterization, habits, naturals enemy and populational fluctuation of Aconophora elongatiformis Dietrich in Tecoma Stans (L.) Juss. Ex Hbk

International Nuclear Information System (INIS)

Pinzon F, Olga Patricia; Quintero C, Paola Fernanda

2001-01-01

The ornamental trees complete a very important environmental function for the quality of the inhabitants' life in the urban areas, when offering momentous benefits as the subduing of the climate, regulation of CO 2 in the atmosphere and the scenic beauty. Thanks to the interest of the District Administration, in Bogota, in the last four years, the urban plantation of trees acquired a preponderant paper that became apparent during the biggest plantation of trees program and maintenance of green areas that it has been carried out in the history of the capital; day by day they get more importance, and they are recognized by the citizenship like fundamental values of its environment. Previously to this program, the attention received were minimum or were remembered soon after the surprising devastating consequences of phyto sanitary problems: the grooved cochineal of the acacia, the louse plant of the cypress and the bedbug of the Urapan in whose cases the ignorance of basic aspects of the biology, natural control and the harmful populations' behavior, it has forced to generally apply measured of chemical type to try to reduce the high levels population. The importance that have, the green areas in the city, it favors a continuous pursuit that allows to deepen in the knowledge of the main risk factors, current problems and potentials of the species, types and consequences of the damages and the intra and inter relationships of the arthropofauna of the urban vegetation, their relationship with the plants, as well as the incidence of biotic and abiotic in the tree phonologic behavior and in the fluctuation of the populations of this individuals in order to coming closer to the understanding of the dynamics of the populations of arthropods harmful, in such a way that is possible to design kind handling strategies with the environment, having in consideration in integrated form the conditions under the attack of arthropods harmful

Hypoxylon pulicicidum sp. nov. (Ascomycota, Xylariales, a pantropical insecticide-producing endophyte.

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Gerald F Bills

Full Text Available BACKGROUND: Nodulisporic acids (NAs are indole diterpene fungal metabolites exhibiting potent systemic efficacy against blood-feeding arthropods, e.g., bedbugs, fleas and ticks, via binding to arthropod specific glutamate-gated chloride channels. Intensive medicinal chemistry efforts employing a nodulisporic acid A template have led to the development of N-tert-butyl nodulisporamide as a product candidate for a once monthly treatment of fleas and ticks on companion animals. The source of the NAs is a monophyletic lineage of asexual endophytic fungal strains that is widely distributed in the tropics, tentatively identified as a Nodulisporium species and hypothesized to be the asexual state of a Hypoxylon species. METHODS AND RESULTS: Inferences from GenBank sequences indicated that multiple researchers have encountered similar Nodulisporium endophytes in tropical plants and in air samples. Ascomata-derived cultures from a wood-inhabiting fungus, from Martinique and closely resembling Hypoxylon investiens, belonged to the same monophyletic clade as the NAs-producing endophytes. The hypothesis that the Martinique Hypoxylon collections were the sexual state of the NAs-producing endophytes was tested by mass spectrometric analysis of NAs, multi-gene phylogenetic analysis, and phenotypic comparisons of the conidial states. We established that the Martinique Hypoxylon strains produced an ample spectrum of NAs and were conspecific with the pantropical Nodulisporium endophytes, yet were distinct from H. investiens. A new species, H. pulicicidum, is proposed to accommodate this widespread organism. CONCLUSIONS AND SIGNIFICANCE: Knowledge of the life cycle of H. pulicicidum will facilitate an understanding of the role of insecticidal compounds produced by the fungus, the significance of its infections in living plants and how it colonizes dead wood. The case of H. pulicicidum exemplifies how life cycle studies can consolidate disparate observations of a

More Pitfalls with Sperm Viability Staining and a Viability-Based Stress Test to Characterize Sperm Quality

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Barbara A. Eckel

2017-12-01

Full Text Available Sperm viability (SV, the proportion of live sperm in a sample, is a widely applied measure of sperm quality but few studies test its robustness. At least three reasons make SV problematic as a surrogate for sperm quality. First, reviewing the ecological literature revealed that previously identified methodological pitfalls have not been overcome, including low cross-study standardization of protocols, inadequate statistical treatment, and unaccounted for within-sample heterogeneity. Second, SV is affected by biological variation such as between species, reproductive organs, or sperm age cohorts. Third, the proportion of live sperm extracted from males appears more related to male than to sperm quality in the sense of the future performance of sperm. We propose an alternative method to assess sperm quality by characterizing the temporal decrease of SV in a stressor medium and illustrate in two species, the common bedbug (Cimex lectularius and the fruit fly (Drosophila melanogaster how some common methodological pitfalls may be circumvented. Our data empirically support the well-known but little-considered facts that (i non-blind measurements may alter SV and (ii that SV frequently have non-significant repeatability within one sample. (iii Cross-sectional sampling of ejaculates showed that this heterogeneity even masked a biological pattern—the sperm stratification within males. We show (iv that this shortcoming can be overcome by following the temporal decline of SV of a sperm subsample in a stress test. Finally, (v comparing the staining pattern of sperm between Cimex and Drosophila, we found that in the latter, the visibility of sperm is substantially delayed (30 min when sperm density is high. We show that this delay in stained sperm visibility was, however, not biased toward dead or live sperm. To measure sperm quality, we advocate analyzing the temporal decline in SV in a stressor medium over current protocols that use SV per se and

Riboflavin Provisioning Underlies Wolbachia's Fitness Contribution to Its Insect Host.

Science.gov (United States)

Moriyama, Minoru; Nikoh, Naruo; Hosokawa, Takahiro; Fukatsu, Takema

2015-11-10

Endosymbiotic bacteria of the genus Wolbachia represent the most successful symbiotic bacteria in the terrestrial ecosystem. The success of Wolbachia has been ascribed to its remarkable phenotypic effects on host reproduction, such as cytoplasmic incompatibility, whereby maternally inherited bacteria can spread in their host populations at the expense of their host's fitness. Meanwhile, recent theoretical as well as empirical studies have unveiled that weak and/or conditional positive fitness effects may significantly facilitate invasion and spread of Wolbachia infections in host populations. Here, we report a previously unrecognized nutritional aspect, the provision of riboflavin (vitamin B2), that potentially underpins the Wolbachia-mediated fitness benefit to insect hosts. A comparative genomic survey for synthetic capability of B vitamins revealed that only the synthesis pathway for riboflavin is highly conserved among diverse insect-associated Wolbachia strains, while the synthesis pathways for other B vitamins were either incomplete or absent. Molecular phylogenetic and genomic analyses of riboflavin synthesis genes from diverse Wolbachia strains revealed that, in general, their phylogenetic relationships are concordant with Wolbachia's genomic phylogeny, suggesting that the riboflavin synthesis genes have been stably maintained in the course of Wolbachia evolution. In rearing experiments with bedbugs (Cimex lectularius) on blood meals in which B vitamin contents were manipulated, we demonstrated that Wolbachia's riboflavin provisioning significantly contributes to growth, survival, and reproduction of the insect host. These results provide a physiological basis upon which Wolbachia-mediated positive fitness consequences are manifested and shed new light on the ecological and evolutionary relevance of Wolbachia infections. Conventionally, Wolbachia has been regarded as a parasitic bacterial endosymbiont that manipulates the host insect's reproduction in a

You can't burn the house down because of one bedbug: a qualitative study of changing gender norms in the prevention of violence against women and girls in an urban informal settlement in India.

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Daruwalla, Nayreen; Hate, Ketaki; Pinto, Preethi; Ambavkar, Gauri; Kakad, Bhaskar; Osrin, David

2017-01-01

Background : The contribution of structural inequalities and societal legitimisation to violence against women, which 30% of women in India survive each year, is widely accepted. There is a consensus that interventions should aim to change gender norms, particularly through community mobilisation. How this should be done is less clear. Methods : We did a qualitative study in a large informal settlement in Mumbai, an environment that characterises 41% of households. After reviewing the anonymised records of consultations with 1653 survivors of violence, we conducted 5 focus group discussions and 13 individual interviews with 71 women and men representing a range of age groups and communities. We based the interviews on fictitious biographical vignettes to elicit responses and develop an understanding of social norms. We wondered whether, in trying to change norms, we might exploit the disjunction between descriptive norms (beliefs about what others actually do) and injunctive norms (beliefs about what others think one ought to do), focusing program activities on evidence that descriptive norms are changing. Results : We found that descriptive and injunctive norms were relatively similar with regard to femininity, masculinity, the need for marriage and childbearing, resistance to separation and divorce, and disapproval of friendships between women and men. Some constraints on women's dress and mobility were relaxing, but there were more substantial differences between descriptive and injunctive norms around women's education, control of income and finances, and premarital sexual relationships. Conclusions : Programmatically, we hope to exploit these areas of mismatch in the context of injunctive norms generally inimical to violence against women. We propose that an under-appreciated strategy is expansion of the reference group: induction of relatively isolated women and men into broader social groups whose descriptive and injunctive norms do not tolerate violence.

You can’t burn the house down because of one bedbug: a qualitative study of changing gender norms in the prevention of violence against women and girls in an urban informal settlement in India [version 2; referees: 2 approved

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Nayreen Daruwalla

2017-11-01

Full Text Available Background: The contribution of structural inequalities and societal legitimisation to violence against women, which 30% of women in India survive each year, is widely accepted. There is a consensus that interventions should aim to change gender norms, particularly through community mobilisation. How this should be done is less clear. Methods: We did a qualitative study in a large informal settlement in Mumbai, an environment that characterises 41% of households. After reviewing the anonymised records of consultations with 1653 survivors of violence, we conducted 5 focus group discussions and 13 individual interviews with 71 women and men representing a range of age groups and communities. We based the interviews on fictitious biographical vignettes to elicit responses and develop an understanding of social norms. We wondered whether, in trying to change norms, we might exploit the disjunction between descriptive norms (beliefs about what others actually do and injunctive norms (beliefs about what others think one ought to do, focusing program activities on evidence that descriptive norms are changing. Results: We found that descriptive and injunctive norms were relatively similar with regard to femininity, masculinity, the need for marriage and childbearing, resistance to separation and divorce, and disapproval of friendships between women and men. Some constraints on women’s dress and mobility were relaxing, but there were more substantial differences between descriptive and injunctive norms around women’s education, control of income and finances, and premarital sexual relationships. Conclusions: Programmatically, we hope to exploit these areas of mismatch in the context of injunctive norms generally inimical to violence against women. We propose that an under-appreciated strategy is expansion of the reference group: induction of relatively isolated women and men into broader social groups whose descriptive and injunctive norms do not tolerate violence