Effects of long-term fixation on histological quality of undecalcified murine bones embedded in methylmethacrylate

While long-term fixation and storage of specimens is common and useful for many research projects, it is particularly important for space flight investigations where samples may not be returned to Earth for several months (International Space Station) or years (manned mission to Mars). We examined two critical challenges of space flight experimentation: the effect of long-term fixation on the quality of mouse bone preservation and the preservation of antigens and enzymes for both histochemical and immunohistochemical analyses, and how the animal/sample processing affects the preservation. We show that long-term fixation minimally affects standard histological staining, but that enzyme histochemistry and immunolabeling are greatly compromised. Further, we demonstrate that whole animal preservation is not as suitable as whole leg or stripped leg preservation for long-term fixation and all histological analyses. Overall, we recommend whole leg processing for long-term storage of bone specimens in fixative prior to embedding in plastic for histological examination.     

Microsatellite DNA markers for Lysiphlebus testaceipes

Microsatellite loci were isolated from the aphid parasitoid Lysiphlebus testaceipes (Hymenoptera: Braconidae). Ten loci were obtained from an enriched partial genomic library. Genetic diversity was analysed at seven of these loci and two natural populations, one on oleander and one on citrus. The observed number of alleles ranged from one to 17, and the observed heterozygosity ranged from 0.37 to 0.82. In both populations, no departure from Hardy–Weinberg equilibrium was detected except for one locus. The differentiation between the two populations was characterized by an F_ST of 0.09.     

Postzygotic isolation between the two European subspecies of the house mouse: estimates from fertility patterns in wild and laboratory-bred hybrids

We assessed the fertility (reproductive success, litter size, testis weight, spermatocyte-to-spermatid ratio) of F₁s and backcrosses between different wild-derived outbred and inbred strains of two mouse subspecies, Mus musculus domesticus and M. m. musculus . A significant proportion of the F₁ females between the outbred crosses did not reproduce, suggesting that female infertility was present. As the spermatocyte-to-spermatid ratio was correlated with testis weight, the latter was used to attribute a sterile vs. fertile phenotype to all males. Segregation proportions in the backcrosses of F₁ females yielded 11 (inbred) to 17% (outbred) sterile males, suggesting the contribution of two to three major genetic factors to hybrid male sterility. Only one direction of cross between the inbred strains produced sterile F₁ males, indicating that one factor was borne by the musculus X-chromosome. No such differences were observed between reciprocal crosses in the outbred strains. The involvement of the X chromosome in male sterility thus could not be assessed, but its contribution appears likely given the limited introgression of X-linked markers through the hybrid zone between the subspecies. However, we observed no sterile phenotypes in wild males from the hybrid zone, although testis weight tended to decrease in the centre of the transect.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 84 , 379–393.     

Monteiro's Storm‐petrel Oceanodroma monteiroi: a new species from the Azores

The existence of two seasonally distinct breeding populations of Oceanodroma storm‐petrels in the Azores islands was first documented in 1996. The discovery of morphological differences between the populations led to the suggestion that they may represent cryptic sibling species. Recent mtDNA and microsatellite analysis from storm‐petrel populations has considerably advanced our understanding of their taxonomic relationships. Here we present new information on the timing of breeding and moult of the two Azores populations, the extent of exchange of individuals between seasons, and diet from feather isotopes. We conclude that the hot‐season Azores population should be considered a new species for which we propose the name Oceanodroma monteiroi, Monteiro's Storm‐petrel. The species is both genetically distinct and genetically isolated from the sympatric cool‐season population of Madeiran Storm‐petrel Oceanodroma castro, and from all other populations of Oceanodroma castro in the Atlantic and Pacific Oceans examined to date. Differences in the vocalizations permit species recognition, and the extent of primary feather wear and stage of moult aids separation of the two species in the Azores, which is especially valuable during August when both attend the breeding colonies in large numbers. Feather carbon and nitrogen isotopes reveal that the diet of Monteiro's Storm‐petrel differs from that of the sympatric Madeiran Storm‐petrel during both breeding and non‐breeding seasons, and unlike the Madeiran Storm‐petrel, Monteiro's Storm‐petrel appears to maintain the same foraging environment during the summer and winter months, though it shows a dietary shift to higher trophic levels during the non‐breeding season. Monteiro's Storm‐petrel is thought to be confined to the Azores archipelago, where it is currently known to nest on just two small neighbouring islets. The total population size was estimated at 250–300 pairs in 1999.     

马鹿茸血酶解肽体内免疫功能及抗氧化功能关系的研究

本文分别选用由木瓜蛋白酶水解天山马鹿茸血获得的肽Ⅰ、肽Ⅱ以及原血为受试样品,研究天山马鹿茸血及其酶解肽对小鼠免疫功能和抗氧化功能的影响,其中肽Ⅰ、肽ⅡDH分别为18．1％、12．2％时,清除OH·能力最强,清除率为50．8％。分别测定了脏器指数,脾细胞增殖实验,血清中溶血素和抗体生成细胞的含量以及小鼠血清总抗氧化能力、SOD活力和MDA含量。结果表明：与对照组相比较,肽Ⅱ组能极显著提高小鼠体液和细胞免疫功能,加强小鼠的抗氧化功能（P〈0．01或P〈0．05）。此外,具有较强抗氧化活性的肽显示出了很强的免疫活性（P〈0．05）。     

Blood Biochemistry of Sea Turtles Captured in Gillnets in the Lower Cape Fear River,North Carolina,USA

ABSTRACT Mortality due to fisheries interactions has been implicated as a contributor to population decline for several species of sea turtle. The incidental capture of sea turtles in the coastal gillnet fisheries of North Carolina, USA, has received much attention in recent years, and mitigation measures to reduce sea turtle mortality due to gillnet entanglement are a high priority for managers and conservationists. Efforts to evaluate effects of gillnet entanglement on sea turtle populations are complicated by the lack of information on health status of turtles released alive from nets and postrelease mortality. We obtained blood samples from green (Chelonia mydas) and Kemp's ridley (Lepidochelys kempii) sea turtles captured in gillnets for 20–240 minutes to assess the impacts of gillnet entanglement on blood biochemistry and physiological status. We measured concentrations of lactate, corticosterone, ions (Na⁺, K⁺, Cl^-, P, Ca²⁺), enzymes (lactate dehydrogenase [LDH], creatine phosphokinase [CPK], aspartate aminotransferase [AST]), protein, and glucose in the blood and also performed physical examinations of turtles to document external indicators of health status (injuries, lethargy, muted reflexes). We evaluated the effects of entanglement time on blood biochemistry and to look for correlations between blood biochemistry and results of the physical examinations. We observed a significant increase in blood lactate, LDH, CPK, phosphorus, and glucose with increased entanglement time. Alterations in blood biochemistry were generally associated with a decline in health status as indicated by results of the physical examination. Although entanglement time plays an important role in determining the health status of sea turtles upon release from a gillnet, our results suggest that factors such as the depth and severity of entanglement may also have an effect on health status of turtles and the probability of postrelease survival. We were unable to set a maximum unattended gillnet soak time to minimize impacts on captured sea turtles, and therefore recommend that fisheries managers continue to enforce the net attendance regulations currently in place in the lower Cape Fear River, North Carolina, during the summer months.     

Drilling and crushing predation on scaphopods from the Miocene of the Netherlands

Klompmaker, A.A. 2011: Drilling and crushing predation on scaphopods from the Miocene of the Netherlands. Lethaia, Vol. 44, pp. 429–439. Reports on the predators of scaphopods are rare. This study records two types of predation traces on the Miocene dentaliid scaphopod Fissidentalium sp. from Langenboom in the Netherlands. The first type is demonstrated by naticid drillholes, located primarily on the middle (and thickest) part of the shell. Based on the examination of more than 700 specimens, the percentage of completely drilled scaphopods is low, at 1%. This is in line with the first graphical overview of drilling percentages on scaphopods through time. The second type of predation is found as jagged, arcuate margins at the functionally anterior end of a significant part of the scaphopod population. These breakages were not caused by pressure due to overburden, as experimental results indicate that such breakages form at right angles to the longitudinal axis of the shell. Reworking was also ruled out, mainly because the breakages were formed at the anterior end of the shell only. Rather, the damage is attributed to carnivorous decapods chipping/peeling with their claws or mandibles. The predation traces suggest that Fissidentalium sp. was a shallow burrower. □Scaphopoda, drillholes, predators, Miocene, the Netherlands, Langenboom     

急性心肌梗死患者冠脉搭桥术前中性粒细胞-淋巴细胞比率与围术期心肌损伤相关分析

目的：探讨急性心肌梗死患者冠脉搭桥（CABG）术前中性粒细胞．淋巴细胞比率（NLR）与围术期心肌损伤的关系,为,临床CABG围术期心肌保护提供参考依据。方法：选取2012年1月至2012年6月于首都医科大学附属北京安贞医院因急性心肌梗死接受冠脉搭桥手术（CABG）患者210例,收集术前血常规及术后肌钙蛋白I（cTnI）？Life酸激酶同工酶（CK-MB）,计算NLR;采用四分位法根据NLR水平将患者分为四组,比较各组cTnI及CK—MB峰值,多元逐步回归分析NLR与cTnI及CK-MB峰值的相关性。结果：随着NLR水平升高,高血压病史和射血分数〈50％患者比例逐渐增多;白细胞计数、术后CK-MB及cTnI峰值、术后血肌酐值均逐渐增加;多元逐步回归分析显示,NLR、WBC分别与cTnI峰值呈正相关（r=0．526,r=0．186,P〈0．05）。结论：术前NLR、WBC与cTnI峰值呈正相关,NLR可能是反应急性心肌梗死患者冠脉搭桥围术期心肌损伤的良好标志物。     

Repercussions of the COVID-19 pandemic on athletes: a cross-sectional study

The COVID-19 pandemic has presented significant challenges and implications for the sports community. Thus, this study aimed to describe the prevalence of COVID-19 in Brazilian athletes and identify the epidemiological, clinical, athletic, life and health factors associated with the disease in these individuals. A cross-sectional study was performed involving 414 athletes from 22 different sports using an online questionnaire from August to November 2020. The association between the athletes’ characteristics and COVID-19 was evaluated using a logistic regression model. The prevalence of COVID-19 was 8.5%, although only 40% of athletes reported having been tested. Being under 27 years of age (3-fold), having children (~5-fold), having a teammate test positive for COVID-19 (2.5-fold), and smoking (14-fold) were associated with a possible higher risk of disease. Almost 20% of athletes self-reported musculoskeletal injuries during the period of the pandemic that was studied. Athletes with a university education (P = 0.02), a profession other than sports (P < 0.001), those from a low-income family (P = 0.01), and public health system users (P = 0.04) were significantly less frequently tested for COVID-19, whereas international competitors, athletes who received a wage, and athletes who had a teammate who tested positive for COVID-19 were 2-, 3-, and 15-fold more likely to be tested for COVID-19, respectively. Approximately 26% of the athletes who tested negative or were untested reported more than three characteristic COVID-19 symptoms, and 11% of athletes who tested positive for COVID-19 were asymptomatic. The identification of modifiable (have children, smoking, and teammates positively tested) and non-modifiable (age under 27 years) factors related to COVID-19 in athletes can contribute to implementing surveillance programmes to decrease the incidence of COVID-19 in athletes and its negative impacts in sports.     

Physiological methods to study biofilm disinfection

This report reviews the development of a rapidin situ approach to study the physiological responses of bacteria within biofilms to disinfectants. One method utilized direct viable counts (DVC) to assess the disinfection efficacy when thin biofilms were exposed to chlorine or monochloramine. Results obtained using the DVC method were one log higher than plate count (PC) estimates of the surviving population after disinfection. Other methods incorporated the use of fluorogenic stains, a cryotomy technique to yield thin (5-m) sections of biofilm communities and examination by fluorescence microscopy. The fluorogenic stains used in this approach included 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), which indicates cellular electron transport activity and Rhodamine 123, which responds specifically to proton motive force. The use of these stains allowed the microscopic discrimination of physiologically active bacteria as well as heterogeneities of active cells within thicker biofilms. The results of experiments using these techniques with pure culture and binary population biofilms on stainless steel coupons indicated biocidal activity of chlorine-based disinfectants occurred initially at the bulk-fluid interface of the communities and progressed toward the substratum. This approach provided a unique opportunity to describe the spatial response of bacteria within biofilms to antimicrobial agents and address mechanisms explaining their comparative resistance to disinfection in a way that has not been possible using traditional approaches. Results obtained using this alternative approach were also consistently higher than PC data following disinfection. These observations suggest that traditional methods involving biofilm removal and bacterial enumeration by colony formation overestimate biocide efficacy. Hence the alternative approach described here more accurately indicates the ability of bacteria surviving disinfection to recover and grow as well as demonstrate spatial heterogeneities in cellular physiological activities within biofilms.