540 research outputs found

    Adverse birth outcomes in United Republic of Tanzania--impact and prevention of maternal risk factors.

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    OBJECTIVE: To determine risk factors for poor birth outcome and their population attributable fractions. METHODS: 1688 women who attended for antenatal care were recruited into a prospective study of the effectiveness of syphilis screening and treatment. All women were screened and treated for syphilis and other reproductive tract infections (RTIs) during pregnancy and followed to delivery to measure the incidence of stillbirth, intrauterine growth retardation (IUGR), low birth weight (LBW) and preterm live birth. FINDINGS: At delivery, 2.7% of 1536 women experienced a stillbirth, 12% of live births were preterm and 8% were LBW. Stillbirth was independently associated with a past history of stillbirth, short maternal stature and anaemia. LBW was associated with short maternal stature, ethnicity, occupation, gravidity and maternal malaria whereas preterm birth was associated with occupation, age of sexual debut, untreated bacterial vaginosis and maternal malaria. IUGR was associated with gravidity, maternal malaria, short stature, and delivering a female infant. In the women who had been screened and treated for syphilis, in between 20 and 34% of women with each outcome was estimated to be attributable to malaria, and 63% of stillbirths were estimated as being attributable to maternal anaemia. Screening and treatment of RTIs was effective and no association was seen between treated RTIs and adverse pregnancy outcomes. CONCLUSION: Maternal malaria and anaemia continue to be significant causes of adverse pregnancy outcome in sub-Saharan Africa. Providing reproductive health services that include treatment of RTIs and prevention of malaria and maternal anaemia to reduce adverse birth outcomes remains a priority

    Single-cell RNAseq reveals seven classes of colonic sensory neuron.

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    OBJECTIVE: Integration of nutritional, microbial and inflammatory events along the gut-brain axis can alter bowel physiology and organism behaviour. Colonic sensory neurons activate reflex pathways and give rise to conscious sensation, but the diversity and division of function within these neurons is poorly understood. The identification of signalling pathways contributing to visceral sensation is constrained by a paucity of molecular markers. Here we address this by comprehensive transcriptomic profiling and unsupervised clustering of individual mouse colonic sensory neurons. DESIGN: Unbiased single-cell RNA-sequencing was performed on retrogradely traced mouse colonic sensory neurons isolated from both thoracolumbar (TL) and lumbosacral (LS) dorsal root ganglia associated with lumbar splanchnic and pelvic spinal pathways, respectively. Identified neuronal subtypes were validated by single-cell qRT-PCR, immunohistochemistry (IHC) and Ca2+-imaging. RESULTS: Transcriptomic profiling and unsupervised clustering of 314 colonic sensory neurons revealed seven neuronal subtypes. Of these, five neuronal subtypes accounted for 99% of TL neurons, with LS neurons almost exclusively populating the remaining two subtypes. We identify and classify neurons based on novel subtype-specific marker genes using single-cell qRT-PCR and IHC to validate subtypes derived from RNA-sequencing. Lastly, functional Ca2+-imaging was conducted on colonic sensory neurons to demonstrate subtype-selective differential agonist activation. CONCLUSIONS: We identify seven subtypes of colonic sensory neurons using unbiased single-cell RNA-sequencing and confirm translation of patterning to protein expression, describing sensory diversity encompassing all modalities of colonic neuronal sensitivity. These results provide a pathway to molecular interrogation of colonic sensory innervation in health and disease, together with identifying novel targets for drug development

    Potent and Broad Neutralization of HIV-1 by a Llama Antibody Elicited by Immunization

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    Llamas (Lama glama) naturally produce heavy chain–only antibodies (Abs) in addition to conventional Abs. The variable regions (VHH) in these heavy chain–only Abs demonstrate comparable affinity and specificity for antigens to conventional immunoglobulins despite their much smaller size. To date, immunizations in humans and animal models have yielded only Abs with limited ability to neutralize HIV-1. In this study, a VHH phagemid library generated from a llama that was multiply immunized with recombinant trimeric HIV-1 envelope proteins (Envs) was screened directly for HIV-1 neutralization. One VHH, L8CJ3 (J3), neutralized 96 of 100 tested HIV-1 strains, encompassing subtypes A, B, C, D, BC, AE, AG, AC, ACD, CD, and G. J3 also potently neutralized chimeric simian-HIV strains with HIV subtypes B and C Env. The sequence of J3 is highly divergent from previous anti–HIV-1 VHH and its own germline sequence. J3 achieves broad and potent neutralization of HIV-1 via interaction with the CD4-binding site of HIV-1 Env. This study may represent a new benchmark for immunogens to be included in B cell–based vaccines and supports the development of VHH as anti–HIV-1 microbicides

    CHEMICAL INTERACTIONS OF CITRATE, CALCIUM AND PHOSPHATE IN A CALCAREOUS SASKATCHEWAN SUBSOIL

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    The addition of citrate into biostimulatory amendment solutions for the in-situ bioremediation of petroleum hydrocarbons is a relatively new concept. Research has shown that addition of citrate in combination with phosphate can potentially decrease P sorption and thus increase P mobility and bioavailability. In this thesis, soil cores from a hydrocarbon-contaminated site were first characterized to determine soil characteristics. The soil cores had a high clay content with heterogeneous soil layers, leading to the hypothesis that preferential flow paths are likely dominant in transport onsite. As a manipulative experiment, soil Ca levels were modified via three treatments, Ca Saturated, Ca Depleted, and the control soil to ascertain the effect of Ca upon citrate and P retention. X-ray fluorescence (XRF) and x-ray diffraction (XRD) confirmed the change in total Ca levels as well as differences in mineralogy of the treated soils. In chapter three, phosphate adsorption isotherms and citrate desorption isotherm experiments were designed to quantify the relationships among soil Ca, P adsorption, and the concentration of citrate (0-50mM) at equilibrium conditions. The results demonstrated that high citrate levels (above 5mM) would allow less P to be adsorbed onto the soil surface. Phosphorus K-edge XANES were measured on soil samples treated with citrate and Ca to determine the relationship between chemical speciation and citrate interactions. The research led to the discovery that higher than expected (>5mM) levels of citrate were required to get a significant desorption in P; higher levels of soil Ca were correlated with more adsorbed P. In chapter four, kinetics experiments combined with a spectroscopic approach yielded a better understanding of the citrate-phosphate-calcium reaction dynamics. By using the Pseudo Second order model, all parameters from the kinetics experiments were highly correlated to model experimental values. The major finding of the kinetic study was that soil Ca level strongly influenced citrate desorption effectiveness. Overall this thesis showed that the connection between Ca, citrate, and P was important in determining rates and mechanisms of chemical interaction and to be able to build and apply a model to the system

    Production, characterization, and antigen specificity of recombinant 62-71-3, a candidate monoclonal antibody for rabies prophylaxis in humans

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    Rabies kills many people throughout the developing world every year. The murine monoclonal antibody (mAb) 62-71-3 was recently identified for its potential application in rabies postexposure prophylaxis (PEP). The purpose here was to establish a plant-based production system for a chimeric mouse-human version of mAb 62-71-3, to characterize the recombinant antibody and investigate at a molecular level its interaction with rabies virus glycoprotein. Chimeric 62-71-3 was successfully expressed in Nicotiana benthamiana. Glycosylation was analyzed by mass spectroscopy; functionality was confirmed by antigen ELISA, as well as rabies and pseudotype virus neutralization. Epitope characterization was performed using pseudotype virus expressing mutagenized rabies glycoproteins. Purified mAb demonstrated potent viral neutralization at 500 IU/mg. A critical role for antigenic site I of the glycoprotein, as well as for two specific amino acid residues (K226 and G229) within site I, was identified with regard to mAb 62-71-3 neutralization. Pseudotype viruses expressing glycoprotein from lyssaviruses known not to be neutralized by this antibody were the controls. The results provide the molecular rationale for developing 62-71-3 mAb for rabies PEP; they also establish the basis for developing an inexpensive plant-based antibody product to benefit low-income families in developing countries.—Both, L., van Dolleweerd, C., Wright, E., Banyard, A. C., Bulmer-Thomas, B., Selden, D., Altmann, F., Fooks, A. R., Ma, J. K.-C. Production, characterization, and antigen specificity of recombinant 62-71-3, a candidate monoclonal antibody for rabies prophylaxis in humans

    Population genomics of domestic and wild yeasts

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    The natural genetics of an organism is determined by the distribution of sequences of its genome. Here we present one- to four-fold, with some deeper, coverage of the genome sequences of over seventy isolates of the domesticated baker's yeast, _Saccharomyces cerevisiae_, and its closest relative, the wild _S. paradoxus_, which has never been associated with human activity. These were collected from numerous geographic locations and sources (including wild, clinical, baking, wine, laboratory and food spoilage). These sequences provide an unprecedented view of the population structure, natural (and artificial) selection and genome evolution in these species. Variation in gene content, SNPs, indels, copy numbers and transposable elements provide insights into the evolution of different lineages. Phenotypic variation broadly correlates with global genome-wide phylogenetic relationships however there is no correlation with source. _S. paradoxus_ populations are well delineated along geographic boundaries while the variation among worldwide _S. cerevisiae_ isolates show less differentiation and is comparable to a single _S. paradoxus_ population. Rather than one or two domestication events leading to the extant baker's yeasts, the population structure of _S. cerevisiae_ shows a few well defined geographically isolated lineages and many different mosaics of these lineages, supporting the notion that human influence provided the opportunity for outbreeding and production of new combinations of pre-existing variation

    Nuevas series del comercio exterior de México, 1870-1929

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    Editada en la Fundación Empresa PúblicaEl artículo se ocupa de reconstruir los valores anuales del comercio exterior de México en el período 1870-1929, la llamada era del capitalismo liberal. Además de las estadísticas oficiales de este país, utiliza las de sus principales socios comerciales: Estados Unidos, Gran Bretaña, Francia y Alemania. Evalúa la calidad y consistencia de las fuentes mexicanas y aplica criterios explícitos para rectificar las cifras oficiales y cubrir las brechas en la información disponible. Asimismo, propone una reagrupación de los valores del comercio que permite distinguir entre el intercambio de mercancías y los flujos de metálico. Como resultado, ofrece series completas del comercio de mercancías y de las transferencias de dinero en especie, así como un cálculo anual de la balanza comercial para todo el período.This paper provides a reconstruction of the yearly values of Mexico's foreign trade within the period 1870-1929, the era of liberal capitalism. It uses the Mexican official statistics as well as those published by Mexico's main trading partners: the United States, Great Britain, France, and Germany. The article assesses the quality and consistency of the Mexican sources and applies explicit criteria to rectify the official figures and to fill the gaps in the available information. It also proposes a new breakdown of trade values, which allows distinguishing between commodity trade and specie movements. As a result, the article provides with complete annual series of commodity trade and specie flows, as well as a yearly estimate of the trade balance throughout the period.Publicad

    Human visceral nociception: findings from translational studies in human tissue.

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    Peripheral sensitization of nociceptors during disease has long been recognized as a leading cause of inflammatory pain. However, a growing body of data generated over the last decade has led to the increased understanding that peripheral sensitization is also an important mechanism driving abdominal pain in highly prevalent functional bowel disorders, in particular, irritable bowel syndrome (IBS). As such, the development of drugs that target pain-sensing nerves innervating the bowel has the potential to be a successful analgesic strategy for the treatment of abdominal pain in both organic and functional gastrointestinal diseases. Despite the success of recent peripherally restricted approaches for the treatment of IBS, not all drugs that have shown efficacy in animal models of visceral pain have reduced pain end points in clinical trials of IBS patients, suggesting innate differences in the mechanisms of pain processing between rodents and humans and, in particular, how we model disease states. To address this gap in our understanding of peripheral nociception from the viscera and the body in general, several groups have developed experimental systems to study nociception in isolated human tissue and neurons, the findings of which we discuss in this review. Studies of human tissue identify a repertoire of human primary afferent subtypes comparable to rodent models including a nociceptor population, the targeting of which will shape future analgesic development efforts. Detailed mechanistic studies in human sensory neurons combined with unbiased RNA-sequencing approaches have revealed fundamental differences in not only receptor/channel expression but also peripheral pain pathways.Non
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