Lambing and placental expulsion time after dexamethasone-induced parturition in Corriedale and Polwarth ewes

To study breed differences in ewes induced to parturition with dexamethasone (DXM), 15 Corriedale and 16 Polwarth ewes were injected with 15 mg of DXM four days before the expected lambing date (Days 144 and 145, respectively) in Experiment 1. Interval from treatment to parturition was twice as long for the Polwarth than for the Corriedale breed (57.9 vs 28.8 hours, P /= 0.05) and on the percentage of ewes retaining the placenta beyond 6 hours (18% vs 0%, P>/= 0.05). Birth weight of lambs was lower in the induced group (3.9 vs 4.5 kg, P相似文献   

Effect of prior ingestion of glucose or fructose on the performance of exercise of intermediate duration

The metabolic responses induced by the ingestion of a beverage containing glucose (G), fructose (F) or placebo (W) 30 min before exercise of high intensity and intermediate duration have been investigated; in these conditions the energy processes are mostly dependent on aerobic reactions. A group of 11 male recreational sportsmen ran on a treadmill, at an intensity corresponding to 82% of peak oxygen consumption, until exhaustion on three different occasions (after ingestion of a beverage containing 75 g of G, 75 g of F or W). Plasma glucose, insulin, and lactic acid concentrations were determined just prior to the ingestion of the beverages, 30 min afterwards and 10 and 30 min after completion of the exercise. The mean endurance time was 644 (SD 261) s after the ingestion of G, 611 (SD 227) s after the ingestion of F and 584 (SD 189) s after the ingestion of the W (P < 0.05 between G and W). No differences in the oxygen uptake, respiratory quotient or lactate concentrations between the three trials were observed. Both plasma glucose and insulin concentrations determined in samples obtained immediately before the onset of exercise were higher when G was ingested than when F (P < 0.05 andP < 0.05, respectively) or W (P < 0.001 and P < 0.005, respectively) were ingested. These findings would suggest that the ingestion of G prior to an effort of intermediate duration may improve physical performance.     

Persistence of Cell Division Synchrony in Spirogyra Insignis (Gamophyceae): Membrane Proteoglycans Transmitting Synchronizing Information Throughout Generations

Spirogyra insignis shows a long-term persistence of cell division synchrony in the absence of the synchronizing Zeitgeber, so that at least six generations are involved in the process. This tentatively suggests that a mechanism of transmission throughout generations of synchronizing information could maintain this synchrony. Apparently, a vital part of the molecular basis of this mechanism is a membrane proteoglycan complex. This complex could obtain temporal information from a synchronizing Zeitgeber and be transmitted to the progeny by distribution of plasma membrane between daughter cells.     

Fascioloides magna (Bassi, 1875) in feral swine from southern Texas.

Between 1971 and 1975, Fascioloides magna was found in 46 of 67 (69%) feral swine (Sus scrofa) in southern Texas. Flukes were recovered from swine in areas where F. magna commonly has been recovered from white-tailed deer and cattle. One to 12 flukes were recovered from each infected animal. Their presence was indicated by black hematin pigment on the liver and various other internal organs. Eggs were not detected in the gallbladder or feces of infected animals although mature flukes and eggs were recovered in the livers suggesting that, like cattle, feral swine can be infected but are aberrant hosts for the parasite and do not disseminate eggs.     

Characterization of the atypical Ppz/Hal3 phosphatase system from the pathogenic fungus Cryptococcus neoformans

Ppz Ser/Thr protein phosphatases (PPases) are found only in fungi and have been proposed as potential antifungal targets. In Saccharomyces cerevisiae Ppz1 (ScPpz1) is involved in regulation of monovalent cation homeostasis. ScPpz1 is inhibited by two regulatory proteins, Hal3 and Vhs3, which have moonlighting properties, contributing to the formation of an unusual heterotrimeric PPC decarboxylase (PPCDC) complex crucial for CoA biosynthesis. Here we report the functional characterization of CnPpz1 (CNAG_03673) and two possible Hal3‐like proteins, CnHal3a (CNAG_00909) and CnHal3b (CNAG_07348) from the pathogenic fungus Cryptococcus neoformans. Deletion of CnPpz1 or CnHal3b led to phenotypes unrelated to those observed in the equivalent S. cerevisiae mutants, and the CnHal3b‐deficient strain was less virulent. CnPpz1 is a functional PPase and partially replaced endogenous ScPpz1. Both CnHal3a and CnHal3b interact with ScPpz1 and CnPpz1 in vitro but do not inhibit their phosphatase activity. Consistently, when expressed in S. cerevisiae, they poorly reproduced the Ppz1‐regulatory properties of ScHal3. In contrast, both proteins were functional monogenic PPCDCs. The CnHal3b isoform was crystallized and, for the first time, the 3D‐structure of a fungal PPCDC elucidated. Therefore, our work provides the foundations for understanding the regulation and functional role of the Ppz1‐Hal3 system in this important pathogenic fungus.     

Population genetic analysis of the genes APOE, APOB(3'VNTR) and ACE in some black and Amerindian communities from Colombia

A population genetic study was carried out with the APOE, APOB and ACE loci in 17 Colombian human populations. Ten of them were Amerindian communities coming from the northeastern part of Colombia, Pacific region, Eastern Plains and Amazonia. Six were black populations from Providence Island, Caribbean and Pacific coasts. Finally, the Mestizo population of Bogota was studied as well. The APOE and ACE loci were in Hardy-Weinberg equilibrium, whereas the APOB locus was not studied in all populations. The genetic heterogeneity was substantially greater among the Amerindian populations (G(ST) = 0.059) than in the Afrocolombian populations (G(ST) = 0.009). Also the gene flow population pair estimates were so much higher among the Afrocolombian populations (Nm = 49.08 +/- 43.07) than among Amerindian populations (Nm = 9.66 +/- 18.04). Different phylogenetic and multivariant analyses showed that the Amerindian populations analyzed were clustered in three different arrays: one constituted by the Colombian northeastern and Pacific populations, the second one by the two Amazon populations (Coreguaje and Nukak) and the last one by the Yuco (the unique Caribbe-speaking population among those studied). The latter population was highly divergent from a genetic point of view from the remainder Amerindian populations studied. By using the Mantel test, the existence of a positive and significant correlation between the genetic and geographical distances found among Amerindian populations was demonstrated. This fact was not observed among the Afrocolombian populations. Nevertheless, an isolation-by-distance Slatkin analysis test did not show a significant clear structure of this special pattern among the Indian tribes studied.     

EVOLUTION OF MICROALGAE IN HIGHLY STRESSING ENVIRONMENTS: AN EXPERIMENTAL MODEL ANALYZING THE RAPID ADAPTATION OF DICTYOSPHAERIUM CHLORELLOIDES (CHLOROPHYCEAE) FROM SENSITIVITY TO RESISTANCE AGAINST 2,4,6‐TRINITROTOLUENE BY RARE PRESELECTIVE MUTATIONS1

The increasing rates of global extinction due to human activities necessitate studies of the ability of organisms to adapt to the new environmental conditions resulting from human disturbances. We investigated the evolutionary adaptation of a microalga to sudden environmental change resulting from exposure to novel toxic chemical residues. A laboratory strain of Dictyosphaerium chlorelloides (Naum.) Kom. and Perm. (Chlorophyceae) was exposed to increasing concentrations of the modern contaminant 2,4,6‐trinitrotoluene (TNT). When algal cultures were exposed to 30 mg·L ^{? 1} 1 Received 9 July 2001. Accepted 23 July 2002.
TNT, massive lysis of microalgal cells was observed. The key to understanding the evolution of microalgae in such a contaminated environment is to characterize the TNT‐resistant variants that appear after the massive lysis of the TNT‐sensitive cells. A fluctuation analysis demonstrated unequivocally that TNT did not facilitate the appearance of TNT‐resistant cells; rather it was found that TNT‐resistant cells appeared spontaneously by rare mutations under nonselective conditions, before exposure to TNT. The estimated mutation rate was 1.4 × 10 ^{? 5} mutants per cell division. Isolated resistant mutants exhibited a diminished fitness in the absence of TNT. Moreover, the gross photosynthetic rate of TNT‐resistant mutants was significantly lower than that of wild‐type cells. Competition experiments between resistant mutants and wild‐type cells showed that in small populations, the resistant mutants were driven to extinction. The balance between mutation rate and the rate of selective elimination determines the occurrence of about 36 TNT‐resistant mutants per million cells in each generation. These scarce resistant mutants are the guarantee of potential for adaptation.     

IL-11 and IL-11Rα immunolocalisation at primate implantation sites supports a role for IL-11 in placentation and fetal development

Embryo implantation, endometrial stromal cell decidualization and formation of a functional placenta are critical processes in the establishment and maintenance of pregnancy. Interleukin (IL)-11 signalling is essential for adequate decidualization in the mouse uterus and IL-11 promotes decidualization in the human. IL-11 action is mediated via binding to the specific IL-11 receptor α (IL-11Rα). The present study examined immunoreactive IL-11 and IL-11Rα in cycling rhesus monkey endometrium, at implantation sites in cynomolgus and rhesus monkeys and in human first trimester decidua and defined distinct spatial and temporal patterns. In cycling rhesus monkey endometrium, IL-11 and IL-11Rα increased in both basalis and functionalis regions during the secretory compared with the proliferative phase, with changing cellular locations in luminal and glandular epithelium and stroma. The patterns were similar overall to those previously described in human endometrium. Differences were seen in immunostaining during implantation in cynomologus and rhesus monkey. In the cynomolgus, very little staining for IL-11 or IL-11Rα was seen in syncytio- and cyto-trophoblast cells in the villi between days 12 and 150 of pregnancy although there was moderate staining in cytotrophoblast in the shell between days 12 and 17 and in subpopulations of cytotrophoblast cells invading the arteries at day 17. By contrast in the rhesus monkey between days 24 and 35 of pregnancy and in human first trimester placenta, cyto- and syncytio-trophoblast in the villi but not cytotrophoblast in the shell were positively stained. The most intense staining for both IL-11 and IL-11Rα was present within the decidua in the maternal component of implantation sites in all three primates but moderate staining was also present in maternal vascular smooth muscle and glands perivascular cells and epithelial plaques. These results are consistent with a role for IL-11 both during decidualization and placentation in primates.     

Neisseria gonorrhoeae Modulates Immunity by Polarizing Human Macrophages to a M2 Profile

Current data suggest that Neisseria gonorrhoeae is able to suppress the protective immune response at different levels, such as B and T lymphocytes and antigen-presenting cells. The present report is focused on gonococcus evasion mechanism on macrophages (MФ) and its impact in the subsequent immune response. In response to various signals MФ may undergo classical-M1 (M1-MФ) or alternative-M2 (M2-MФ) activation. Until now there are no reports of the gonococcus effects on human MФ polarization. We assessed the phagocytic ability of monocyte-derived MФ (MDM) upon gonococcal infection by immunofluorescence and gentamicin protection experiments. Then, we evaluated cytokine profile and M1/M2 specific-surface markers on MФ challenged with N. gonorrhoeae and their proliferative effect on T cells. Our findings lead us to suggest N. gonorrhoeae stimulates a M2-MФ phenotype in which some of the M2b and none of the M1-MФ-associated markers are induced. Interestingly, N. gonorrhoeae exposure leads to upregulation of a Programmed Death Ligand 1 (PD-L1), widely known as an immunosuppressive molecule. Moreover, functional results showed that N. gonorrhoeae-treated MФ are unable to induce proliferation of human T-cells, suggesting a more likely regulatory phenotype. Taken together, our data show that N. gonorroheae interferes with MФ polarization. This study has important implications for understanding the mechanisms of clearance versus long-term persistence of N. gonorroheae infection and might be applicable for the development of new therapeutic strategies.     

Accelerated hand bone mineral density loss is associated with progressive joint damage in hands and feet in recent-onset rheumatoid arthritis

Introduction

To investigate whether accelerated hand bone mineral density (BMD) loss is associated with progressive joint damage in hands and feet in the first year of rheumatoid arthritis (RA) and whether it is an independent predictor of subsequent progressive total joint damage after 4 years.

Methods

In 256 recent-onset RA patients, baseline and 1-year hand BMD was measured in metacarpals 2-4 by digital X-ray radiogrammetry. Joint damage in hands and feet were scored in random order according to the Sharp-van der Heijde method at baseline and yearly up to 4 years.

Results

68% of the patients had accelerated hand BMD loss (>-0.003 g/cm²) in the first year of RA. Hand BMD loss was associated with progressive joint damage after 1 year both in hands and feet with odds ratios (OR) (95% confidence intervals [CI]) of 5.3 (1.3-20.9) and 3.1 (1.0-9.7). In univariate analysis, hand BMD loss in the first year was a predictor of subsequent progressive total joint damage after 4 years with an OR (95% CI) of 3.1 (1.3-7.6). Multivariate analysis showed that only progressive joint damage in the first year and anti-citrullinated protein antibody positivity were independent predictors of long-term progressive joint damage.

Conclusions

In the first year of RA, accelerated hand BMD loss is associated with progressive joint damage in both hands and feet. Hand BMD loss in the first year of recent-onset RA predicts subsequent progressive total joint damage, however not independent of progressive joint damage in the first year.