Effect of arachidonic acid on duodenal enterocyte ATPases

Duodenal ion transport processes are supported by ATPase enzymes in basolateral membranes of the enterocyte. In vivo studies have shown that long term n-6 poly-unsaturated fatty acid (PUFA) supplementation in rats causes increases in intestinal Ca absorption, coupled with a higher total calcium balance and bone calcium content. The present in vitro study was undertaken to test the effect of arachidonic acid (AA), a highly unsaturated (and thus physiologically potent) member of the n-6 PUFA family, on ATPases in enterocyte basolateral membranes isolated with a sorbitol density gradient procedure. This paper presents results which show that AA inhibits Na+,K+-ATPase in a dose-dependent manner (-67% of basal activity at a concentration of 30 microg/ml, P < 0.005) but that this effect is not mediated by protein kinase C, as shown by the use of the protein kinase C blocker calphostin (0.5 microM). Indomethacin (IDM) at 0.1 mM, a cyclo-oxygenase blocker, could also not reverse the inhibitory effect of AA on Na+,K+-ATPase. Ca2+-ATPase, on the other hand, is not affected significantly (-10%, P > 0.05) by arachidonic acid at 30 microg/ml.     

The macroinvertebrate fauna of littoral and bottom substrata as a tool for biotypology of Frisian waters

During a biotypological research of surface waters in the province of Friesland, The Netherlands, the macroinvertebrate fauna was sampled, both from the littoral and bottom substrata. Results of this investigation in different types of water on 60 and 55 stations in 1981 and 1982, respectively, are presented. The species richness in the littoral samples exceeded that of the bottom samples, and the samples per station had relatively few species in common. Even in many cases the most abundant taxon was a different one in both samples of the same spot. With multivariate analysis of the data sets from bottom, littoral and total samples a fairly good resemblance was found between these data sets. It is concluded that the semi-quantitative processing of macroinvertebrate fauna data leads to reliable results. One can use one sample per station, wherein different substrata are combined. Distinct clusters were recognized in more extreme environmental conditions such as brackish and acid waters. With the help of the macroinvertebrate fauna the other types of water could not easily be differentiated.     

中国黑龙江水系茴鱼属一新纪录种(鲑形目,茴鱼科)

2006年10～11月,在黑龙江水系(中国境内)的乌苏里江、呼玛河、额木尔河等河流采集到茴鱼属鱼类标本,经鉴定为中国1新纪录种--下游黑龙江茴鱼Thymallus tugarinae.下游黑龙江茴鱼体色鲜艳,背部无或具少量黑色斑点,体侧具鲜艳橙色条纹,明显区别于属内其它物种.与同分布于黑龙江水系的黑龙江茴鱼T.grubii相比,两者在以下性状上存在明显区别:1)新纪录种体侧背部无或仅具少数黑色斑点,后者体侧具有大量黑色斑点;2)新纪录种背鳍鳍条数为23～26,后者为19～22;3)新纪录种体侧具多行间断开的鲜艳橙色条纹,后者无;4)新纪录种背鳍边缘红色带纹宽阔,后者狭窄;5)分布区不同,新纪录种仅分布于黑龙江中下游,后者仅分布于黑龙江中上游.     

Physiological profile of world-class high-altitude climbers

The functional characteristics of six world-class high-altitude mountaineers were assessed 2-12 mo after the last high-altitude climb. Each climber on one or several occasions had reached altitudes of 8,500 m or above without supplementary O2. Static and dynamic lung volumes and right and left echocardiographic measurements were found to be within normal limits of sedentary controls (SC). Muscle fiber distribution was 70% type I, 22% type IIa, and 7% type IIb. Mean muscle fiber cross-sectional area was significantly smaller than that of SC (-15%) and of long-distance runners (LDR, -51%). The number of capillaries per unit cross-sectional area was significantly greater than that of SC (+ 40%). Total mitochondrial volume was not significantly different from that of SC, but its subsarcolemmal component was equal to that of LDR. Average maximal O2 consumption was 60 +/- 6 ml X kg-1 X min-1, which is between the values of SC and LDR. Average maximal anaerobic power was 28 +/- 2.5 W X kg-1, which is equal to that of SC and 40% lower that that of competitive high jumpers. All subjects were characterized by resting hyperventilation both in normoxia and in moderate (inspired O2 partial pressure = 77 Torr) hypoxia resulting in higher oxyhemoglobin saturation levels in hypoxia. The ventilatory response to four tidal volumes of pure O2 was similar to that of SC. It is concluded that elite high-altitude climbers do not have physiological adaptations to high altitude that justify their unique performance.     

Effects of general,specific and combined warm-up on explosive muscular performance

The purpose of this study was to compare the acute effects of general, specific and combined warm-up (WU) on explosive performance. Healthy male (n = 10) subjects participated in six WU protocols in a crossover randomized study design. Protocols were: passive rest (PR; 15 min of passive rest), running (Run; 5 min of running at 70% of maximum heart rate), stretching (STR; 5 min of static stretching exercise), jumping [Jump; 5 min of jumping exercises – 3x8 countermovement jumps (CMJ) and 3x8 drop jumps from 60 cm (DJ60)], and combined (COM; protocols Run+STR+Jump combined). Immediately before and after each WU, subjects were assessed for explosive concentric-only (i.e. squat jump – SJ), slow stretch-shortening cycle (i.e. CMJ), fast stretch-shortening cycle (i.e. DJ60) and contact time (CT) muscle performance. PR significantly reduced SJ performance (p =0.007). Run increased SJ (p =0.0001) and CMJ (p =0.002). STR increased CMJ (p =0.048). Specific WU (i.e. Jump) increased SJ (p =0.001), CMJ (p =0.028) and DJ60 (p =0.006) performance. COM increased CMJ performance (p =0.006). Jump was superior in SJ performance vs. PR (p =0.001). Jump reduced (p =0.03) CT in DJ60. In conclusion, general, specific and combined WU increase slow stretch-shortening cycle (SSC) muscle performance, but only specific WU increases fast SSC muscle performance. Therefore, to increase fast SSC performance, specific fast SSC muscle actions must be included during the WU.     

2002年至2007年太原地区儿童细菌性腹泻病原菌分布及耐药分析

目的了解太原地区近6年儿童细菌性腹泻病原菌分布及耐药情况。方法对临床诊断细菌性腹泻病,便培养已分离到病原菌1080例作回顾性分析,分析其病原菌的分布及耐药情况。结果埃希菌属486株（45％）,居于首位,前5位的病原菌依次为埃希菌属、肠球菌属、酵母样真菌、志贺菌属、假单胞菌属。各年均以大肠埃希菌为主要检出菌,志贺菌逐年减少。年龄分布中,婴儿的构成比最高（44．4％）。埃希菌属、志贺菌属、假单胞菌属、沙门菌属、气单胞菌属此5种杆菌对13种抗生素的平均耐药率依次为舒普深、痢特灵、头孢他啶、庆大霉素、环丙沙星、头孢哌酮、头孢曲松、丁胺卡那、头孢噻肟、诺氟沙星、头孢呋辛、哌拉西林、头孢唑啉。从埃希菌属近6年的耐药性变迁资料可以看出,对13种抗生素的耐药率均有不同程度上升。结论传统的致病菌志贺菌属、沙门菌属较少,而肠球菌属、假单胞菌属、枸橼酸杆菌属、克雷伯杆菌属、肠杆菌属、酵母样真菌等条件致病菌肠炎占有相当比例。各种致病菌的耐药性增加,第三代头孢除头孢他啶的耐药率较低外,其余都较高。提示应严格掌握抗生素用药指证,合理选用抗生素。     

抗冻蛋白特征、作用机理与预测新进展

抗冻蛋白（antifreezeproteins,AFPs）可以通过抑制冰晶生长保护生物体免受低温冻害,具有重要的生物学意义和应用价值。现在在鱼类、节肢动物、植物及微生物中均发现有AFPs的存在。基于对已有研究文献和相关网络数据的系统调查统计,详细描述了AFPs数据的类别特征,并对其作用机理的研究历史和最新取得的突破性进展作了较为系统的阐述,并对AFPs预测所取得的成果作了介绍,还对AFPs研究的现状和未来研究方向作了讨论和展望。     

籼粳稻杂交衍生RIL系的苗期抗旱性评价

为鉴定籼粳稻杂交衍生系的苗期抗旱性,以课题组自育的高代抗逆品系ZD15为母本、籼稻品种IR29为父本,以及杂交衍生的重组自交系群体120份为试验材料,利用PEG-6000对各材料苗期进行干旱胁迫处理,测定根长、根冠比、地上部鲜重、地下部鲜重、地上部干重和地下部干重;利用PEG-6000对各材料芽期进行干旱胁迫处理,测定芽鞘长和芽长。采用主成分分析和隶属函数法对各材料的抗旱性进行综合评价,根据综合抗旱D值可将122份材料分成3类,D值在0.201～0.400之间的有33份,属于不抗旱材料;D值在0.401～0.600之间的有79份,属于中等抗旱材料;D值在0.601～0.800之间的有10份,属于抗旱材料。利用D值进行逐步回归分析,结果表明根长、根冠比、地上部鲜重、地下部鲜重、地上部干重、地下部干重、芽鞘长和芽长8个性状均可作为水稻苗期抗旱性的评价指标。本研究筛选出的抗旱材料,可作为育种中间材料进一步培育,或作为育种资源加以利用,以丰富本区水稻育种的资源库。