Functional characterization of Aquaporin-like genes in the human bed bug Cimex lectularius

AbstractThe bed bug Cimex lectularius is a blood-feeding re-emerging annoyance pest insect that has the ability to transmit Trypanosoma cruzi under experimental laboratory conditions. Aquaporins (AQPs) are water channel proteins that are essential in biological organisms. C. lectularius are constantly exposed to water-related stress, suggesting that AQPs may offer novel control avenues. We identified and cloned four AQPs from C. lectularius, assessed tissue and lifestage-specific expression, and characterized biochemical functions in vitro and in vivo. We identified an efficient water-specific AQP (ClAQP1), two aquaglyceroporins (ClGlp1 and ClGlp2) and a homolog of Drosophila melanogaster big brain (ClBib). ClGlp1 was only functional when co-expressed with the water-specific AQP. Simultaneous RNAi gene silencing of ClAQP1 and ClGlp1 significantly reduced water and urea excretion post blood feeding. The Bib homologue was enriched in embryos, exclusively expressed in ovaries, and when silenced, dramatically increased bug fecundity. Our data demonstrate that AQPs have critical roles in excretion, water homeostasis and reproduction in C. lectularius, and could be potential targets for control in this notorious pest.</jats:p

Duplication, concerted evolution and purifying selection drive the evolution of mosquito vitellogenin genes

<p>Abstract</p> <p>Background</p> <p>Mosquito vitellogenin (<it>Vtg</it>) genes belong to a small multiple gene family that encodes the major yolk protein precursors required for egg production. Multiple <it>Vtg </it>genes have been cloned and characterized from several mosquito species, but their origin and molecular evolution are poorly understood.</p> <p>Results</p> <p>Here we used <it>in silico </it>and molecular cloning techniques to identify and characterize the evolution of the <it>Vtg </it>gene family from the genera <it>Culex</it>, <it>Aedes/Ochlerotatus</it>, and <it>Anopheles</it>. We identified the probable ancestral <it>Vtg </it>gene among different mosquito species by its conserved association with a novel gene approximately one kilobase upstream of the start codon. Phylogenetic analysis indicated that the <it>Vtg </it>gene family arose by duplication events, but that the pattern of duplication was different in each mosquito genera. Signatures of purifying selection were detected in <it>Culex</it>, <it>Aedes </it>and <it>Anopheles</it>. Gene conversion is a major driver of concerted evolution in <it>Culex</it>, while unequal crossover is likely the major driver of concerted evolution in <it>Anopheles</it>. In <it>Aedes</it>, smaller fragments have undergone gene conversion events.</p> <p>Conclusions</p> <p>The study shows concerted evolution and purifying selection shaped the evolution of mosquito <it>Vtg </it>genes following gene duplication. Additionally, similar evolutionary patterns were observed in the <it>Vtg </it>genes from other invertebrate and vertebrate organisms, suggesting that duplication, concerted evolution and purifying selection may be the major evolutionary forces driving <it>Vtg </it>gene evolution across highly divergent taxa.</p

Twice-daily application of HIV microbicides alters the vaginal microbiota

Vaginal HIV microbicides offer great promise in preventing HIV transmission, but failures of phase 3 clinical trials, in which microbicide-treated subjects had an increased risk of HIV transmission, raised concerns about endpoints used to evaluate microbicide safety. A possible explanation for the increased transmission risk is that the agents shifted the vaginal bacterial community, resulting in loss of natural protection and enhanced HIV transmission susceptibility. We characterized vaginal microbiota, using pyrosequencing of bar-coded 16S rRNA gene fragments, in samples from 35 healthy, sexually abstinent female volunteer subjects (ages 18 to 50 years) with regular menses in a repeat phase 1 study of twice-daily application over 13.5 days of 1 of 3 gel products: a hydroxyethylcellulose (HEC)-based “universal” placebo (10 subjects), 6% cellulose sulfate (CS; 13 subjects), and 4% nonoxynol-9 (N-9; 12 subjects). We used mixed effects models inferred using Bayesian Markov chain Monte Carlo methods, which showed that treatment with active agents shifted the microbiota toward a community type lacking significant numbers of Lactobacillus spp. and dominated by strict anaerobes. This state of the vaginal microbiota was associated with a low or intermediate Nugent score and was not identical to bacterial vaginosis, an HIV transmission risk factor. The placebo arm contained a higher proportion of communities dominated by Lactobacillus spp., particularly L. crispatus, throughout treatment. The data suggest that molecular evaluation of microbicide effects on vaginal microbiota may be a critical endpoint that should be incorporated in early clinical assessment of microbicide candidates. IMPORTANCE Despite large prevention efforts, HIV transmission and acquisition rates remain unacceptably high. In developing countries, transmission mainly occurs through heterosexual intercourse, where women are significantly more vulnerable to infection than men. Vaginal microbicides are considered to be one of the most promising female-controlled products, in that women themselves insert the microbicides into the vagina to prevent HIV transmission during sexual intercourse. The failure of several microbicides in clinical trials has raised questions concerning the low in vivo efficacy of such anti-HIV molecules. This study was designed to gain insights into the failures of two microbicides by testing the hypothesis that the microbicides negatively affect a critical line of defense against HIV, the vaginal microbiota. The results suggest that in the early assessment of candidate microbicides, culture-independent evaluation of their effect on the vaginal microbiota should be considered and may constitute a critical endpoint

Microscopic Structure of High-Spin Vibrational Excitations in Superdeformed 190,192,194Hg

Microscopic RPA calculations based on the cranked shell model are performed to investigate the quadrupole and octupole correlations for excited superdeformed bands in 190Hg, 192Hg, and 194Hg. The K=2 octupole vibrations are predicted to be the lowest excitation modes at zero rotational frequency. At finite frequency, however, the interplay between rotation and vibrations produces different effects depending on neutron number: The lowest octupole phonon is rotationally aligned in 190Hg, is crossed by the aligned two-quasiparticle bands in 192Hg, and retains the K=2 octupole vibrational character up to the highest frequency in 194Hg. The gamma vibrations are predicted to be higher in energy and less collective than the octupole vibrations. From a comparison with the experimental dynamic moments of inertia, a new interpretation of the observed excited bands invoking the K=2 octupole vibrations is proposed, which suggests those octupole vibrations may be prevalent in SD Hg nuclei.Comment: 22 pages, REVTeX, 12 postscript figures are available on reques

Varizes colônicas idiopáticas: um relato de caso: Idiopathic colonic varices: a case report

As varizes colônicas são uma condição patológica rara, determinada como dilatações tortuosas do plexo vascular submucoso que, ao sofrerem rupturas espontâneas, provocam sangramento para o interior da luz intestinal, sendo diagnosticadas através de colonoscopia ao buscar a causa de sangramento gastrointestinal. Geralmente são vistas em associação com cirrose hepática, hipertensão portal ou oclusão da veia mesentérica. O presente estudo relata o caso de um paciente masculino, 46 anos, que deu entrada no Hospital Regional de Presidente Prudente – SP apresentando quadro de enterorragia, sendo diagnosticado com varizes de cólon

Paracoccidioidomicose acarretando Síndrome Colestática: relato de caso: Paracoccidioidomycosis causing Cholestatic Syndrome: a case report

Introdução: Síndrome Colestática engloba as doenças que acometem as vias biliares resultando em colestase, que é classificada em extra e intra-hepática. Uma causa rara de colestase extra-hepática é a causada pela paracoccidioidomicose, onde há a compressão externa da via biliar pelo comprometimento generalizado de linfonodos. Objetivo: Relatar caso em que uma síndrome colestática é causada por Paracoccidioidomicose, devido obstrução extrínseca da via biliar. Relato do caso: Paciente M. T. M., sexo masculino, 35 anos, procedente de região rural em Presidente Prudente, história de alcoolismo e uso de drogas, com queixa de dor de início insidioso em epigastro e irradiação para hipocôndrio direito, acompanhado de febre e inapetência e evoluindo com icterícia e colúria. Foi submetido a internação com suspeita inicialmente de coledocolitíase e após exames de imagem, compressão extrínseca da árvore biliar extra-hepática de provável etiologia neoplásica. No entanto, após a realização de biópsia foi confirmado diagnóstico de PCM cursando com quadro atípico de colestase. Discussão: A forma de manifestação pode dificultar o diagnóstico imediato de PCM, ao mimetizar outras doenças obstrutivas das vias biliares, mostrando, portanto, a importância como diagnóstico diferencial independentemente da faixa etária, principalmente por ser a principal causa de micose sistêmica no Brasil, ressaltando em especial a investigação em populações de zonas rurais endêmicas

Relato de caso: Tumor neuroendócrino de apêndice cecal: Case report: neuroendocrine Tumor of the cecal appendix

Os tumores neuroendócrinos são neoplasias raras que podem surgir em várias localizações. Os tumores neuroendócrinos do apêndice cecal são o terceiro tumor neuroendócrino mais frequente no trato gastrointestinal e aparecem principalmente em idades mais jovens. Na sua grande maioria são identificados através do estudo histopatológico na sequência de uma apendicectomia por suspeita de apendicite aguda. Em casos raros podem causar síndrome carcinoide. Atualmente, são utilizados os sistemas de classificação da Organização Mundial de Saúde e da European Neuroendocrine Tumor Society, os quais têm por base a taxa mitótica e/ou o índice proliferativo Ki-67. O tratamento de escolha dos tumores neuroendócrinos do apêndice cecal é a apendicectomia simples e em casos selecionados pode ser necessária a realização de colectomia direita. A apendicectomia simples é o tratamento cirúrgico de rotina e proporciona a cura na maioria dos casos. Os critérios propostos pela European Neuroendocrine Tumor Society para o tratamento desses tumores são de fácil reprodução mesmo os tumores de apêndice cecal sendo neoplasias relativamente raras, porém com um excelente prognóstico

Relato de caso tumor de celulas da granulosa juvenil de ovario : Case report ovarian juvenile granulosa cell tumor of the ovary

A neoplasia de ovário é uma doença rara na infância. O TCGJ (Tumor de Células da Granulosa Juvenil) é um tumor incomum nesta faixa etária, com bom prognóstico em estágios iniciais, porém com risco de evolução maligna metastática em quadros mais avançados e com diagnóstico tardio. O estudo relata o caso de uma paciente de 6 anos de idade com quadro de dor abdominal inespecífica e progressiva de um mês de evolução. Os estudos complementares demostraram uma massa suspeita em hipogástrio de provável origem anexial direita associada a liquido livre em cavidade abdominal. Após tratamento cirúrgico o estudo anatomopatológico e imunohistologico da peça demonstra um tumor de células da granulosa juvenil

Hemorragia digestiva baixa maciça como apresentação de linfoma primário do cólon: relato de caso e revisão de literatura: Lower gastrointestinal bleeding secondary to primary limphoma of the colon: case report and literature review

O linfoma primário do cólon é uma entidade rara, compreendendo menos de 0,5% de todos os tumores da região. A apresentação inicial do quadro é por vezes inespecífica, dificultando um diagnóstico precoce e levando a complicações como obstrução, perfuração intestinal e hemorragia. Apesar de infrequente, a hemorragia intestinal baixa por tumor linfoide do cólon pode se apresentar de forma maciça, com instabilidade hemodinâmica e oferecendo risco de morte. Várias são as opções diagnósticas e terapêuticas na urgência, incluindo terapia endoscópica, por radiologia intervencionista ou cirurgia

African tropical rainforest net carbon dioxide fluxes in the twentieth century

The African humid tropical biome constitutes the second largest rainforest region, significantly impacts global carbon cycling and climate, and has undergone major changes in functioning owing to climate and land-use change over the past century. We assess changes and trends in CO2 fluxes from 1901 to 2010 using nine land surface models forced with common driving data, and depict the inter-model variability as the uncertainty in fluxes. The biome is estimated to be a natural (no disturbance) net carbon sink (−0.02 kg C m−2 yr−1 or −0.04 Pg C yr−1, p < 0.05) with increasing strength fourfold in the second half of the century. The models were in close agreement on net CO2 flux at the beginning of the century (σ1901 = 0.02 kg C m−2 yr−1), but diverged exponentially throughout the century (σ2010 = 0.03 kg C m−2 yr−1). The increasing uncertainty is due to differences in sensitivity to increasing atmospheric CO2, but not increasing water stress, despite a decrease in precipitation and increase in air temperature. However, the largest uncertainties were associated with the most extreme drought events of the century. These results highlight the need to constrain modelled CO2 fluxes with increasing atmospheric CO2 concentrations and extreme climatic events, as the uncertainties will only amplify in the next century