Histopathology of retained bovine fetal membranes

Placentomes were obtained from 20 cows with retained placenta (9 following normal birth, 5 after abortion and 6 with dystocia), and this material was examined by light microscopy. Histologic changes that were consistently seen in placentomes of cows with retained placenta after normal birth included vascular changes (edema, thrombosis and vasculitis) and the presence of numerous clumps of bacterialcolonies in the connective tissue of the caruncles and cotyledons. Only a few binucleate cells were seen in these cases. In placentomes obtained from cows with retained placenta after abortion, there were instances of focal necrosis of the fetal villi and the presence of variable numbers of binucleate cells. Vascular changes and numerous clumps of bacterial colonies in the caruncles and cotyledons were also noted. The changes in placentomes obtained from cows with retained placenta and dystocia included the presence of numerous binucleate cells, infiltration of polymorphonuclear cells in the connective tissue of both the fetal and maternal villi, vascular changes, and the presence of extensive necrosis and numerous clumps of bacterial colonies. Significant differences (P < 0.05) were encountered in the number of binucleate cells in the various groups. Binucleate cells appear to be involved in the process of placental separation in cows with retained placenta.     

Effect of high fluoride intake on haematological aspects of the mouse.

The effect of feeding adult Swiss albino mice of both sexes a diet supplemented with 0, 125, 250 and 500 parts/10(6) of fluoride for four and eight week periods on haemoglobin concentration (Hb), packed cell volume (PCV) and mean corpuscular haemoglobin concentration (MCHC) was investigated. Values of the three parameters were significantly lowered at both periods in the treated groups as compared with the controls. The extent of reduction in these values was, in general, dependent on the dose of supplemented dietary fluoride. Clinical symptoms were not observed before the end of the sixth week. However, appearance of the symptoms did not change the trend of variations in Hb, PCV and MCHC values. The reduced values could be the result of lowered haemoglobin synthesis and erythropoiesis. It was suggested that these haematological indices could serve to detect preclinical effects of high fluoride intake with an added dose of as low as 125 parts/10(6), or even less, for a period of four weeks or probably earlier.     

Synthesis,Design, and Biological Evaluation of Novel Diethylphenylcarbamothioylphosphonate

Russian Journal of Bioorganic Chemistry - The aim of this work was to synthesize a diethyl phenylcarbamothioyl phosphonate (EThmP) and evaluate its biological activities. ThmP has been prepared...     

When mental fatigue maybe characterized by Event Related Potential (P300) during virtual wheelchair navigation

The goal of this study is to investigate the influence of mental fatigue on the event related potential P300 features (maximum pick, minimum amplitude, latency and period) during virtual wheelchair navigation. For this purpose, an experimental environment was set up based on customizable environmental parameters (luminosity, number of obstacles and obstacles velocities). A correlation study between P300 and fatigue ratings was conducted. Finally, the best correlated features supplied three classification algorithms which are MLP (Multi Layer Perceptron), Linear Discriminate Analysis and Support Vector Machine. The results showed that the maximum feature over visual and temporal regions as well as period feature over frontal, fronto-central and visual regions were correlated with mental fatigue levels. In the other hand, minimum amplitude and latency features didn’t show any correlation. Among classification techniques, MLP showed the best performance although the differences between classification techniques are minimal. Those findings can help us in order to design suitable mental fatigue based wheelchair control.     

Field estimates of fitness costs of the pace‐of‐life in an endangered damselfly

Theory predicts that within‐population differences in the pace‐of‐life can lead to cohort splitting and produce marked intraspecific variation in body size. Although many studies showed that body size is positively correlated with fitness, many argue that selection for the larger body is counterbalanced by opposing physiological and ecological selective mechanisms that favour smaller body. When a population split into cohorts with different paces of life (slow or fast cohort), one would expect to detect the fitness–size relationship among and within cohorts, that is, (a) slower‐developing cohort has larger body size and higher fitness than faster‐developing cohort, and (b) larger individuals within each cohort show higher fitness than smaller individuals. Here, we test these hypotheses in capture–mark–recapture field surveys that assess body size, lifespan, survival and lifetime mating success in two consecutive generations of a partially bivoltine aquatic insect, Coenagrion mercuriale, where the spring cohort is slower‐developing than the autumn cohort. As expected, body size was larger in the slow‐developing cohort, which is consistent with the temperature‐size rule and also with the duration of development. Body size seasonal variation was greater in slow‐developing cohort most likely because of the higher variation in age at maturity. Concordant with theory, survival probability, lifespan and lifetime mating success were higher in the slow‐developing cohort. Moreover, individual body size was positively correlated with survival and mating success in both cohorts. Our study confirms the fitness costs of fast pace‐of‐life and the benefits of larger body size to adult fitness.     

Mapping the microtubule binding regions of calponin

The smooth muscle basic calponin interacts with F-actin and inhibits the actomyosin ATPase in a calmodulin or phosphorylation modulated manner. It also binds in vitro to microtubules and its acidic isoform, present in nonmuscle cells, and co-localizes with microfilaments and microtubules in cultured neurons. To assess the physiological significance and the molecular basis of the calponin-microtubule interaction, we have first studied the solution binding of recombinant acidic calponin to microtubules using quantitative cosedimentation analyses. We have also characterized, for the first time, the ability of both calponin isoforms to induce the inhibition of the microtubule-stimulated ATPase activity of the cytoskeletal, kinesin-related nonclaret dysjunctional motor protein (ncd) and the abolition of this effect by calcium calmodulin. This property makes calponin a potent inhibitor of all filament-activated motor ATPases and, therefore, a potential regulatory factor of many motor-based biological events. By combining the enzymatic measurements of the ncd-microtubules system with various in vitro binding assays employing proteolytic, recombinant and synthetic fragments of basic calponin, we further unambiguously identified the interaction of microtubules at two distinct calponin sites. One is inhibitory and resides in the segment 145-182, which also binds F-actin and calmodulin. The other one is noninhibitory, specific for microtubules, and is located on the COOH-terminal repeat-containing region 183-292. Finally, quantitative fluorescence studies of the binding of basic calponin to the skeletal pyrenyl F-actin in the presence of microtubules did not reveal a noticeable competition between the two sets of filaments for calponin. This result implies that calponin undergoes a concomitant binding to both F-actin and microtubules by interaction at the former site with actin and at the second site with microtubules. Thus, in the living cells, calponin could potentially behave as a cross-linking protein between the two major cytoskeletal filaments.     

Fast liquid chromatography-mass spectrometry glutathione measurement in whole blood: micromolar GSSG is a sample preparation artifact

We describe a new, fast (6 min) and reliable method to measure reduced or oxidized glutathione (GSH) or (GSSG) in whole blood. The method is based on a LC/MS measurement in positive electrospray ionization mode after a chromatographic separation on a specific column which does not need any counter-ion in the mobile phase, improving the sensitivity of detection. A 50 microl sample of whole blood is sufficient for analysis. We demonstrate that the lack of an alkylating agent during the sample preparation brings out an underestimation of GSH and an artefactual production of GSSG, corresponding to 2-3% of GSH. The simultaneous use of N-ethyl-maleimide and a strong deproteinising acid prevents these two drawbacks. This efficient and new method of preparation and analysis lets us show that, unexpectedly, GSH is stable in whole blood for some hours and that deproteinised samples can be stored without GSH loss for at least three weeks at -20 or -80 degrees C. The reference interval, measured on 22 volunteers, on blood samples collected either with heparin or with EDTA, is 1310 +/- 118 microM for GSH and 0.62 microM for GSSG. The within-run precision of this method, with gamma glutamyl-glutamic acid as an internal standard, evaluated in three successive series (n = 30), lies between 2.1 and 4.8% for a GSH level at 580 or 1150 microM. The one step sample preparation we propose seems well suited for GSH routine measurements in hospital laboratories and avoids any underestimation of GSH, a now well accepted biomarker of oxidative stress.     

Genotypic and Phenotypic Profiles of Enterotoxigenic <Emphasis Type="Italic">Escherichia coli</Emphasis> Associated with Acute Diarrhea in Tunis,Tunisia

No past studies of acute diarrhea in Tunisia have examined the phenotypic and genotypic profiles of enterotoxigenic Escherichia coli (ETEC) isolates. We determined 65 ETEC isolates derived from a total of 327 E. coli isolates collected from a previous study (acute diarrheal and healthy persons, children and adults n = 214) and 32 E. coli isolates derived from an acute diarrheal outbreak in Kabaria-Ennour city, Tunis. All E. coli isolates were screened by polymerase chain reaction (PCR) for ETEC virulence genes: sta (heat-stable toxin gene) and elt (heat-labile toxin gene). Seventy-two percent (47 of 65) of ETEC strains expressed the sta gene only, 21.5% (14 of 65) expressed the elt gene and 6.1% (4 of 65) expressed both genes. For the outbreak isolates, the elt gene was predominant (10 isolates out of 14). Ganylioside GM1 enzyme-linked immunosorbent assay (GM1-ELISA) was used to validate the PCR results and this was confirmed by dot blot assay. The same results were obtained. The most common colonization factors (CFs) were CFA/I (44.6%) and coli surface antigen 6 (CS6) (11%), and 44.6% of the isolates showed no association with either CFAs. Resistance of ETEC isolates to tetracycline (38.5%), streptomycin (26%), and beta-lactam agents (ticarcillin 26%, amoxicillin 24.6%, cephalotin 21.5%) was common. Regarding serotypes, the majority of ETEC isolates serotyped as O86:H(-) (n = 16), O128:H2 (n = 11), and O127:H21 (n = 10). Other serotypes found were O111:H(-) (n = 6) and O126: H(-) (n = 5). DNA macrorestriction fragment analysis by pulsed-field gel electrophoresis (PFGE) using the XbaI enzyme was conducted to investigate the epidemiological clonal relationship among ETEC isolates. Major patterns were identified among which some of outbreak ETEC isolates belonged. These data suggest that a proportion of acute diarrhea in Tunis represents the confluence of small epidemics by clonality-related ETEC isolates that are transiently introduced or that persist in our community.