不同剂量玛咖对力竭运动致大鼠运动性低血糖的保护作用

目的：探讨不同剂量玛咖对力竭运动致大鼠运动性低血糖的保护作用。方法：采用递增负荷力竭游泳训练的方法建立运动性低血糖动物模型。55只42 d龄雄性Wistar大鼠随机分为5组：①静止对照组（C组）,②运动对照组（M组）,③~⑤运动+低、中、高剂量玛咖组（LM I、LM Ⅱ,LM Ⅲ组）,每组10只（剔除不符合实验要求的大鼠5只）。每天灌胃（ig）1次,LM各组灌胃玛咖的剂量为0.2,0.4,1.2 g/kg体重,灌胃体积为5 ml/kg体重,C、M组灌胃等体积生理盐水。运动大鼠采用递增负荷力竭游泳训练42 d,42 d力竭游泳训练后,测定体重、力竭游泳时间,取血、肝脏及深层股四头肌检测相关生化指标。结果：与C组比较,M组体重、血糖水平、肌糖原与肝糖原含量、肝细胞磷酸烯醇式丙酮酸羧激酶（phosphoenol pyruvate carboxy kinase,PEPCK）表达、肝细胞阳性染色累计吸光度均值等均明显降低（P<0.05或P<0.01）;力竭游泳时间无明显差异;血乳酸含量明显升高（P<0.01）。与M组比较,LM各组体重、血糖水平、肌糖原与肝糖原含量、肝细胞PEPCK表达、肝细胞阳性染色累计吸光度均值等均明显升高（P<0.05或P<0.01）,力竭游泳时间明显延长（P<0.01）,血乳酸含量明显降低（P<0.01）。与LM I组比较,LMⅢ组体重无明显差异,LM Ⅲ组血糖水平、肌糖原与肝糖原含量、肝细胞PEPCK表达、肝细胞阳性染色累计吸光度均值等均明显升高（P<0.05）,力竭游泳时间明显延长,血乳酸含量明显降低（P<0.05）。结论：高剂量玛咖可有效抑制和延缓长时间、大负荷运动导致的运动性低血糖和运动性疲劳的发生与发展,其机制可能与优化肌糖原和肝糖原的储备量及上调糖异生限速酶PEPCK的表达,提高PEPCK活性,促进糖异生有关。     

Identification of target proteins of clinical immunity to Plasmodium falciparum in a region of low malaria transmission

The target molecules of antibodies against falciparum malaria remain largely unknown. Recently we have identified multiple proteins as targets of immunity against Plasmodium falciparum using African serum samples. To investigate whether potential targets of clinical immunity differ with transmission intensity, we assessed immune responses in residents of low malaria transmission region in Thailand. Malaria asymptomatic volunteers (Asy: n = 19) and symptomatic patients (Sym: n = 21) were enrolled into the study. Serum immunoreactivity to 186 wheat germ cell-free system (WGCFS)-synthesized recombinant P. falciparum asexual-blood stage proteins were determined by AlphaScreen, and subsequently compared between the study groups. Forty proteins were determined as immunoreactive with antibody responses to 35 proteins being higher in Asy group than in Sym group. Among the 35 proteins, antibodies to MSP3, MSPDBL1, RH2b, and MSP7 were significantly higher in Asy than Sym (unadjusted p < 0.005) suggesting these antigens may have a protective role in clinical malaria. MSP3 reactivity remained significantly different between Asy and Sym groups even after multiple comparison adjustments (adjusted p = 0.033). Interestingly, while our two preceding studies using African sera were conducted differently (e.g., cross-sectional vs. longitudinal design, observed clinical manifestation vs. functional activity), those studies similarly identified MSP3 and MSPDBL1 as potential targets of protective immunity. This study further provides a strong rationale for the application of WGCFS-based immunoprofiling to malaria vaccine candidate and biomarker discovery even in low or reduced malaria transmission settings.     

Hypolipemia,hypoglycemia, and inactivation of glycogen phosphorylase in Locusta migratoria

Feeding starved adult migratory locusts, Locusta migratoria, caused decreases of hemolymph lipid concentrations and of the percentage of active fat body glycogen phosphorylase which suggested that a molecule(s) from the neurosecretory system or the midgut may have been released to regulate metabolism. Fat body phosphorylase was also inactivated after insects were transferred from 0 to 25 ° C. In adults with elevated hemolymph lipid levels after the injection of small doses of corpus cardiacum extract (CC), feeding did not induce a decrease in hemolymph lipid concentrations. It appears that the processes initiated by feeding could not override the effects of the continued presence of adipokinetic hormone(s) (AKHs) in the hemolymph or their long-term effects. Aqueous, methanolic, or ethanolic extracts of brains or storage lobes (SL) of fed locust CC did not lead to decreases of hemolymph lipid concentrations. Bovine insulin was equally inactive when tested at doses which were previously reported to reduce lipid levels. Fractions of ethanolic brain extracts from 3-day-starved males collected after high-performance size-exclusion chromatography, however, produced hypoglycemic effects in fed males. Two biologically active fractions were found, one with high (≥ 10 kDa) and one with low molecular weight (approximately 1 kDa). © 1995 Wiley-Liss, Inc.     

Comparison of rates of fecal colonization with extended‐spectrum beta‐lactamase‐producing enterobacteria among patients in different wards,outpatients and medical students

Because asymptomatic carriage of extended‐spectrum beta‐lactamase (ESBL) producers is a risk factor for infection, data on colonization dynamics are important when planning infection control. This study investigated fecal colonization with ESBL producers among inpatients, outpatients and medical students and compares the characteristics of ESBL producers among these groups. Carriage rates were investigated in 5581 fecal samples; 4343 from inpatients (330, 1397, 619 and 1864 from adult ICUs [intensive care units], adult non‐ICUs, pediatric ICUs and pediatric non‐ICUs, respectively), 814 from outpatients and 424 from screening of medical students. ESBL producers were characterized by co‐resistance, integrons carried, and aminoglycoside resistance and ESBL genes. Dynamic regression models were built to identify relationships between combinations of time series of monthly antibiotic consumption, prevalence of carriers and infected subjects. Inpatients, ICU patients and adults showed higher prevalence than outpatients, non‐ICU patients or children (7.4%, 9.3% and 12.0% vs. 3.1%, 6.1% and 4.1%, respectively). Klebsiella pneumoniae was more frequent in ICU patients; dominance of CTX‐M‐15 producers was more marked in adult than in pediatric inpatients. ESBL carriage was shown to be a consequence of infection in adults in the time‐series analysis; antibiotic consumption had little effect. The epidemiology of colonization with ESBL producers differed between pediatric ICU, adult ICU and adult non‐ICU patients. In adults, carriage of ESBL producers seems to be the consequence of infection, especially in ICU patients; the main source of colonization is nosocomial acquisition. In contrast, children are less likely to acquire colonizer strains in hospitals; importation of ESBL producers by colonized children seems to be significant.     

The Metabolism of Purine and Pyrimidine Nucleotides in Rat Cortex During Insulin-Induced Hypoglycemia and Recovery

Brains of paralysed rats with insulin-induced hypoglycemia were frozen in situ after spontaneous EEG activity had been absent for 5 or 15 min (“coma”). Recovery (30 min) was achieved in a different group of rats by administering glucose after a 30-min coma period. Purine and pyrimidine nucleotides, nucleosides and free bases were determined in the cortical extracts by high pressure liquid chromatography (HPLC). The ATP values obtained with the HPLC method were in excellent agreement with those obtained using standard enzymatic/fluorometric techniques, while values for ADP and AMP obtained with the HPLC method were significantly lower. Comatose animals showed a severe (40-80%) reduction in the concentrations of all nucleoside triphosphates (ATP. GTP, UTP and CTP) and a simultaneous increase in the concentrations of all nucleoside di- and monophosphates, including that of IMP. The adenine nucleotide pool size decreased to 50% of control level. The concentrations of the nucleosides adenosine, inosine, and uridine increased 50- to 250-fold, while the concentrations of the purine bases, xanthine and hypoxanthine, rose 2- and 30-fold, respectively. There were no increases in the concentrations of adenine, guanine, or xanthosine. Following glucose administration there was a partial (ATP, UTP and CTP) or almost complete (GTP) recovery of the nucleoside triphosphate levels. During recovery, the levels of nucleosidc di- and monophosphates and of adenosine decreased to values close to control; the rise in the inosine level was only partially reversed, and the concentrations of hypoxanthine and xanthine rose further. The adenine nucleotide pool size was only partially restored (to 67% of control value). The adenine nucleotide pool size was not increased by i.p. injection of adenosine or adenine under control condition, or during the posthypoglycemic recovery period.     

Basal and stress-induced corticosterone levels of garden warblers,Sylvia borin,during migration

Summary Plasma levels of the metabolically and behaviorally active corticosteroid hormone, corticosterone, were studied in garden warblers in the laboratory and in the field during the autumnal migratory phase. Garden warblers showing nocturnal migratory activity in the laboratory had elevated levels of corticosterone at the end of the dark phase and low levels during daytime. When nocturnal migratory activity was experimentally disrupted by food deprivation and subsequent refeeding or after spontaneous termination of migratory activity this rhythm was absent. Garden warblers stopping over in the Sahara desert during autumnal migration had low levels of corticosterone. Levels were negatively correlated with fat stores and body mass in birds sampled throughout the day. These levels were generally lower than those associated with stress in response to repeated handling and blood sampling. The results suggest (1) the existence of diel changes in adrenocortical hormonal activity that could be involved in regulation of migration, and (2) that garden warblers carrying large fat depots are not stressed by prolonged flight or lack of appropiate feeding areas during migration over the desert.Abbreviations ACTH adrenocorticotrope hormone - cpm counts per minute - EtOH ethanol - RIA radioimmunoassay     

Postprandial Hypoglycemia in Patients after Gastric Bypass Surgery Is Mediated by Glucose-Induced IL-1β

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Impact of human disturbance in Japan on the distribution and diel activity pattern of terrestrial mammals

Human disturbance has been identified as a contributing factor to the worldwide changes in wildlife ecology. Particularly, the human disturbance forced wildlife from diurnal to nocturnal activity patterns. However, the impact of human disturbances on the spatiotemporal patterns small- and medium-sized terrestrial mammals is unknown. In this study, we then aimed to evaluate the impact of anthropogenic factors on spatial pattern and to clarify the differences in temporal patterns between human disturbed and undisturbed habitats. Our camera trap survey was conducted in northern Gifu Prefecture in central Japan from November 2019 to April 2021. We investigated the impact of human activity on relative abundance indices and the influence of the quantitative difference in human activities on diel activity patterns of 12 terrestrial mammals. In this study, the human population and bamboo forest category negatively affected the RAIs of sika deer and wild boars. Moreover, Asian black bears and wild boars showed crepuscular/nocturnal and cathemeral activity in the human undisturbed habitat, respectively, and nocturnal activity in the human disturbed habitat. Consequently, three large mammals avoided human activity temporally (Asian black bears), spatially (sika deer), and spatiotemporally (wild boars). On the other hand, there was no significant impact of human activity on the spatiotemporal patterns of other mammals. However, it is necessary for residents in the human disturbed habitat to be recognize the risk of human-wildlife conflicts.     

Timing of nocturnal autumn migratory departures in juvenile European robins (Erithacus rubecula) and endogenous and external factors

Many passerine medium distance nocturnal migrants take off from stopover sites not only at the beginning of the night, but also in the middle and at the end of the night. In this paper, we tested two explanations for this phenomenon: (1) that departure time is governed by fuel stores, and (2) that departure time is influenced by the weather. The relationship of temporal distribution of migratory nocturnal departures with body condition and weather factors was studied in juvenile European robins (Erithacus rubecula) during autumn migration. The study was done on the Courish Spit on the Baltic Sea in 1997–2003 by retrapping 74 ringed birds in high mist nets during nocturnal migratory departure. Departure time was not related to fuel stores at arrival and departure, stopover duration, fuel deposition rate or progress of the season. Nor did the local weather at departure influence departure time. A possible reason was a large variation in the behaviour of the birds. European robins which made 1-day stopovers arrived and departed during better weather conditions than birds that stopped over for longer periods. In the former cohort, a significant model with four predictors explained 55% of variation in departure time. It is assumed that weather at the night of departure and during the previous night influenced the time of take-offs in these birds. In robins which made long stopovers, departure time is probably governed by their individual endogenous circadian rhythms of activity, which are related to the environment in a complex way.     

Microhabitat use by foraging white-clawed crayfish (<Emphasis Type="Italic">Austropotamobius pallipes</Emphasis>) in stream pools in the NE Iberian Peninsula

The white-clawed crayfish (Austropotamobius pallipes) is an endangered species across most of its distribution range, and information on its ecological requirements is needed to implement effective conservation measures. Its habitat use has been studied in different areas and at various spatial scales. However, being a nocturnal species, there is scarce information on its habitat selection during foraging periods. In this work we analyse nocturnal habitat use of white-clawed crayfish in pools of a small stream in the northeastern Iberian Peninsula at two different scales: (1) microhabitat selection and (2) pool characteristics. Large crayfish showed a clear positive selection for deeper microhabitats, a selection pattern that was weaker for medium-sized crayfish and absent for small ones. On the other hand, crayfish of all sizes avoided cobble and boulder microhabitats and positively selected fine substrate and more exposed microhabitats. Crayfish abundance in pools was positively influenced by pool area, pool depth and the availability of fine substrates, especially silt. While studies on white-clawed crayfish habitat use have often stressed the importance of rough substrates as crayfish refuge, our results show that fine substrates are positively selected by foraging crayfish of all size classes and promoted active crayfish abundance in pools. These apparently contradictory results may be due to the differences in microhabitat preferences exhibited by active and inactive crayfish. Thus, our results help to better complete the picture of white-clawed crayfish habitat requirements.