Evaluation of enzyme-linked immunosorbent assay using crude Leishmania and recombinant antigens as a diagnostic marker for canine visceral leishmaniasis

The performances of ELISA assays with different antigen preparations, such as Leishmania amazonensis or L. chagasi lysates and the recombinant antigens rK-39 and rK-26, were compared using sera or eluates from dried blood collected on filter paper to detect anti-Leishmania antibodies in dogs from a visceral leishmaniasis-endemic area in Brazil. Of 115 IFAT-reactive dogs at 1:40 titre, 106 (92.2%) were positive in parasitological exams (skin and/or spleen). These animals were compared to healthy animals (n = 25), negative for IFAT at a titre of 1:40 and parasitological exams. The sensitivities of crude and recombinant antigens were similar and remarkably high for both sera and eluates (97-100%). Specificity was higher than 96% for sera and eluates for different antigens, except for L. chagasi antigen using eluates (88%). Concordance values among the tests were higher either for sera or eluates (J = 0.95-1.00). High concordances were observed between sera and eluates tested with different antigens (kappa = 0.93-0.97). Crude and recombinant antigens identified different clinical phases of canine leishmaniasis. These results show that eluates could be used in canine surveys to identify L. chagasi infection. Recombinant antigens added little when compared to crude antigen in identifying positive dogs. Cross-reactivity with other diseases whose distribution often overlaps VL-endemic areas is a limitation of crude antigen use however.     

The use of multi-parameter flow cytometry to study the impact of limiting substrate, agitation intensity, and dilution rate on cell aggregation during Bacillus licheniformis CCMI 1034 aerobic continuous culture fermentations

The main objective of this work was to establish those factors either physical (power input) or chemical (limiting substrate or dilution rate) that enhance cell aggregation (biofilm or floc formation) and cell physiological state during aerobic continuous cultures of Bacillus licheniformis. Glucose-limited steady-state continuous cultures growing at a dilution rate between 0.64 and 0.87/h and 1,000 rpm (mean specific energy dissipation rate (epsilonT) = 6.5 W/kg), led to the formation of a thin biofilm on the vessel wall characterized by the presence of a high proportion of healthy cells in the broth (after aggregate disruption by sonication) defined as having intact polarized cytoplasmic membranes. An increased epsilonT (from 6.5 W/kg to 38 W/kg) was found to hinder cell aggregation under carbon limitation. The carbon recovery calculated from glucose indicated that additional extracellular polymer was being produced at dilution rates >0.87/h. B. licheniformis growth under nitrogen limitation led to floc formation which increased in size with dilution rate. Counter-intuitively the flocs became more substantial with an increase in epsilonT from 6.5 W/kg to 38 W/kg under nitrogen limitation. Indeed the best culture conditions for enhanced metabolically active cell aggregate formation was under nitrogen limitation at epsilonT = 6.5 W/kg (leading to floc formation), and under carbon limitation at a dilution rate of between 0.64 and 0.87/h, at epsilonT = 6.5 W/kg (leading to vessel wall biofilm formation). This information could be used to optimize culture conditions for improved cell aggregation and hence biomass separation, during thermophilic aerobic bioremediation processes.     

Downregulation of RKIP is associated with poor outcome and malignant progression in gliomas

Malignant gliomas are highly infiltrative and invasive tumors, which precludes the few treatment options available. Therefore, there is an urgent need to elucidate the molecular mechanisms underlying gliomas aggressive phenotype and poor prognosis. The Raf Kinase Inhibitory protein (RKIP), besides regulating important intracellular signaling cascades, was described to be associated with progression, metastasis and prognosis in several human neoplasms. Its role in the prognosis and tumourigenesis of gliomas remains unclear. In the present study, we found that RKIP protein is absent in a low frequency (10%, 20/193) of glioma tumors. Nevertheless, the absence of RKIP expression was an independent prognostic marker in glioma. Additionally, by in vitro downregulation of RKIP, we found that RKIP inhibition induces a higher viability and migration of the cells, having no effect on cellular proliferation and angiogenesis, as assessed by in vivo CAM assay. In conclusion, this is the largest series studied so far evaluating the expression levels of this important cancer suppressor protein in glioma tumors. Our results suggest that in a subset of tumors, the absence of RKIP associates with highly malignant behavior and poor survival of patients, which may be a useful biomarker for tailored treatment of glioma patients.     

Comparison of Overall Obesity and Body Fat Distribution in Predicting Risk of Mortality

Results of studies comparing overall obesity and abdominal adiposity or body fat distribution with risk of mortality have varied considerably. We compared the relative importance and joint association of overall obesity and body fat distribution in predicting risk of mortality. Participants included 5,799 men and 6,429 women aged 30–102 years enrolled in the third National Health and Nutrition Examination Survey who completed a baseline health examination during 1988–1994. During a 12‐year follow‐up (102,172 person‐years), 1,188 men and 925 women died. In multivariable‐adjusted analyses, waist‐to‐thigh ratio (WTR) in both sexes (P_trend <0.01 for both) and waist‐to‐hip ratio (WHR) in women (P_trend 0.001) were positively associated with mortality in middle‐aged adults (30–64 years), while BMI and waist circumference (WC) exhibited U‐ or J‐shaped associations. Risk of mortality increased with a higher WHR and WTR among normal weight (BMI 18.5–24.9 kg/m²) and obese (BMI ≥30.0 kg/m²) adults. In older adults (65–102 years), a higher BMI in both sexes (P_trend <0.05) and WC in men (P_trend 0.001) were associated with increased survival, while remaining measures of body fat distribution exhibited either no association or an inverse relation with mortality. In conclusion, ratio measures of body fat distribution are strongly and positively associated with mortality and offer additional prognostic information beyond BMI and WC in middle‐aged adults. A higher BMI in both sexes and WC in men were associated with increased survival in older adults, while a higher WHR or WTR either decreased or did not influence risk of death.     

Angiotensin (1–7) and its receptor Mas are expressed in the human testis: implications for male infertility

The presence of classical components of the renin-angiotensin system has been demonstrated in the male reproductive tract, mainly in the testes and epididymis. The objective of this study was to verify the localization of angiotensin (Ang)-(1–7) and its receptor Mas in human testis. The study included 12 men with previously proven fertility submitted to orchiectomy for prostate cancer and 20 infertile men submitted to testicular biopsy for infertility work-up, comprising a subgroup with obstructive azoospermia/normal spermatogenesis (n = 8) and another with non-obstructive azoospermia and severely impaired spermatogenesis (n = 12). Testicular tissue samples were processed by immunohistochemistry and real time polymerase chain reaction. Ang-(1–7) was strongly expressed in the interstitial compartment, mainly in Leydig cells, with similar intensity in all groups evaluated. The peptide was also detected in the seminiferous tubules, but with much less intensity compared to interstitial cells. The receptor Mas was equally distributed between interstitial and tubular compartments and was found in all layers of the normal seminiferous epithelium. However, neither Ang-(1–7) nor Mas were detected in the seminiferous tubules of samples with impaired spermatogenesis. The testicular samples of infertile men with impaired spermatogenesis (non-obstructive azoospermia) expressed Mas and ACE2 mRNA at lower concentrations (fold change = 0.06 and 0.04, respectively, P < 0.05) than samples with full spermatogenesis (obstructive azoospermia). This shows, for the first time, the immunolocalization of Ang-(1–7) and its receptor Mas in testes of fertile and infertile men, and suggests that this system may be altered when spermatogenesis is severely impaired.     

Degradation of keratinous materials by the plant pathogenic fungus <Emphasis Type="Italic">Myrothecium verrucaria</Emphasis>

In this paper it is described for the first time the capability of Myrothecium verrucaria to grow in submerged and solid state cultures using poultry feathers as the only substrate. The fungus produced a protease with an unusual keratinolytic activity among plant pathogenic fungi. Its crude protease hydrolyzed keratinous substrates at pH 9.0 and 40 °C in the following order: poultry feather keratin > sheep wool keratin > human nail keratin > human hair keratin. Protease activity was highly sensitive to phenylmethyl sulphonyl fluoride (PMSF) indicating that the enzyme belonged to the serine protease family.     

Prometaphase APCcdh1 activity prevents non-disjunction in mammalian oocytes

The first female meiotic division (meiosis I, MI) is uniquely prone to chromosome segregation errors through non-disjunction, resulting in trisomies and early pregnancy loss. Here, we show a fundamental difference in the control of mammalian meiosis that may underlie such susceptibility. It involves a reversal in the well-established timing of activation of the anaphase-promoting complex (APC) by its co-activators cdc20 and cdh1. APC(cdh1) was active first, during prometaphase I, and was needed in order to allow homologue congression, as loss of cdh1 speeded up MI, leading to premature chromosome segregation and a non-disjunction phenotype. APC(cdh1) targeted cdc20 for degradation, but did not target securin or cyclin B1. These were degraded later in MI through APC(cdc20), making cdc20 re-synthesis essential for successful meiotic progression. The switch from APC(cdh1) to APC(cdc20) activity was controlled by increasing CDK1 and cdh1 loss. These findings demonstrate a fundamentally different mechanism of control for the first meiotic division in mammalian oocytes that is not observed in meioses of other species.     

Removal of inorganic anions from drinking water supplies by membrane bio/processes

This paper is designed to provide an overview of the main membrane-assisted processes that can be used for the removal of toxic inorganic anions from drinking water supplies. The emphasis has been placed on integrated process solutions, including the emerging issue of membrane bioreactors. An attempt is made to compare critically recently reported results, reveal the best existing membrane technologies and identify the most promising integrated membrane bio/processes currently being under investigation. Selected examples are discussed in each case with respect to their advantages and limitations compared to conventional methods for removal of anionic pollutants. The use of membranes is particularly attractive for separating ions between two liquid phases (purified and concentrated water streams) because many of the difficulties associated with precipitation, coagulation or adsorption and phase separation can be avoided. Therefore, membrane technologies are already successfully used on large-scale for removal of inorganic anions such as nitrate, fluoride, arsenic species, etc. The concentrated brine discharge and/or treatment, however, can be problematic in many cases. Membrane bioreactors allow for complete depollution but water quality, insufficiently stable process operation, and economical reasons still limit their wider application in drinking water treatment. The development of more efficient membranes, the design of cost-effective operating conditions, especially long-term operations without or with minimal membrane inorganic and/or biological fouling, and reduction of the specific energy consumption requirements are the major challenges.     

Production of polyhydroxyalkanoates by mixed microbial cultures

Polyhydroxyalkanoates (PHAs) are biodegradable bioplastics formed from renewable resources, like sugars, with similar characteristics of polypropylene. These bioplastics are industrially produced by pure cultures using expensive pure substrates. These factors lead to a much higher selling price of PHAs compared to petroleum-based plastics, like polypropylene. The use of mixed cultures and cheap substrates (waste materials) can reduce costs of PHA production by more than 50%. Storage of PHAs by mixed populations occurs under transient conditions mainly caused by discontinuous feeding and variation in the electron donor/acceptor presence. In the last years the mechanisms of storage, metabolism and kinetics of mixed cultures have been studied. The maximum capacity of PHA storage and production rate is dependent on the substrate and on the operating conditions used. In this paper an overview and discussion of various mechanisms and processes for PHA production by mixed cultures is presented.