温度对溶藻弧菌HY9901株致病性相关蛋白的调控

将溶藻弧菌HY9901株置于15℃、20℃、28℃、37℃四个温度下培养,18h时分别测定细菌含量,胞外蛋白酶（Extracelluar protease, ECPase）表达量以及胞外产物（Extracellular product, ECP）对动物的致死性。结果表明,随着温度升高, 菌液浓度、ECPase的活性以及ECP对小鼠和红笛鲷的致死率先升高后下降。28℃培养的细菌浓度、ECPase的活性以及ECP对小鼠和红笛鲷的致死率均为最大。用聚丙烯酰胺凝胶电泳（SDS-PAGE）分析不同温度培养下细菌的ECP和外膜蛋白(Outer membrane protein, OMP),结果显示,不同温度培养的溶藻弧菌ECP和OMP电泳图谱不同。溶藻弧菌主要ECP的分子量为70kD和62kD。ECP 70kD在20℃时的表达量最大,而28℃时ECP 62 kD的蛋白浓度最高。45kD OMP随着温度升高,其合成量增大,28℃时达最大值;而40kD和34kD OMP则随着温度的升高而减弱。通过研究电泳纯化的ECP 62kD和ECP 70kD的酶活性和致死试验,证明ECP 62kD具有很强的酶活性和毒性, 而ECP 70kD仅具有弱的酶活性和毒性。     

高寒地区根田鼠的体温调节与蒸发失水

对栖息于青藏高原地区的草食性小型哺乳动物根田鼠的代谢率、热传导、体温和蒸发失水等生理生态特征随环境温度的变化进行了测定,结果表明：根田鼠代谢水平较高,热传导率也较高,但体温相对较低;蒸发失水在体温调节中占十分重要的地位;这些特点对于栖居于日温差较大,年温差相对较小的环境中具重要的适应意义,说明动物在长期适应进化过程中,面临的主要选择压力是寒冷。结合同域分布的其它物种的生理生态特征,提出了高寒地区草食性小型兽拥有较高的代谢水平,较高的热传导率和相对较低的体温的观点。     

大绒鼠体温调节和产热特征

大绒鼠为横断山脉地区小型哺乳动物的典型代表; 其体温仅能在15～30℃范围内维持稳定; 在热中性区内, 最低静止代谢率为2.71±0.13 ml O₂/g.h, 为其体重预期值的203.2±10.13%; F-值 {(RMR/Me)/(Cm/ C'} 为0.99±0.05; 在 25℃的NSTmax为 5.18±0.19)ml O₂/g.h; BAT 重量为0.33±0.05 g, 为体重的0.84%, BAT细胞线粒体的产热活性较高;肝脏也具有较强的产热活性。大绒鼠的产热特征和体温调节模式很可能反映了横断山地区小型啮齿动物的特征。     

倭蜂猴静止代谢率和体温调节的研究

通过研究倭蜂猴在不同环境温度下的静止代谢率和体温调节特征发现；倭蜂猴（Ｎｙｃｔｉｃｅｂｕｓ ｐｙｇｍａｅｃｕｓ）的ＲＭＲ为０．４９８±０．０３９６０２ｍｌ／ｈｒ．ｇ，仅为预期值的６３．７％；热中性区不明显，实测 下临界温度为３０℃；平均最低热传导为０． ０８０４±０． ００２１０２ｍｌ／ｈｒ． ｓ．℃；在室温下平均体温为３３． ８ ±０．１８℃；在冷压下体温变化较大，温调指数为０．５３５；在高温时主要以高体温和分泌唾液进行体温调节。显示典型热带原猴类动物热能代谢特征。     

REGULATION OF HAEMOPOIESIS IN ALTERED GRAVITY

(1) The aetiology of one of the most striking physiological changes occurring during space-flight, the loss of red blood cells, remains unknown, and its precise time-pattern in flight has not yet been studied. (2) It is suggested that the changes during space-flight responsible for loss of red blood cells in man are (a) loss of plasma volume resulting from disappearance of hydrostatic pressure in the circulation during weightlessness and (b) reduced energy expended in maintenance of form, posture and locomotion resulting from elimination of the usual gravitational load on the muscles. Quadrupeds, like rats, would be expected to suffer minimal blood shifts in weightlessness and therefore have an unchanged plasma volume. However, since in weightlessness the activity-related energy expenditure by the muscles is reduced, the accompanying reduced oxygen demand by the tissues would cause a reduction in erythropoietin levels and so in the production of red blood cells, and a progressive lowering of the total red blood cell mass toward a new steady-state level. (3) Loss of plasma volume alone does not explain the observed loss of red blood cells in astronauts because, in the three manned Skylab missions, as the duration of the missions increased, loss of red blood cell mass decreased, whereas loss of plasma volume increased. This discrepancy is, however, well accounted for by the above hypothesis by taking into consideration the increased level of exercise of the astronauts as the duration of the mission increased. (4) Though water submersion of human subjects does mimic the effects of weightlessness, such effects were overriden in sea mammals because of adaptation to other factors associated with a life in the sea. (5) From the presented analysis of haemopoietic changes observed in spaceflight, an experiment can be designed for a future flight to uncover the causes and mechanisms of these changes and provide a basis for developing protective measures. Thus, the space environment can be used as an investigative tool to enhance the knowledge of the function of the haemopoietic system, which is a major homeostatic system of man and other vertebrates.     

COMPETITION BETWEEN HERMIT HUMMINGBIRDS PHAETHORNINAE AND INSECTS FOR NECTAR IN A COSTA RICAN RAIN FOREST

Hummingbirds in the tropical rainforests of southwestern Costa Rica face intense competition from stingless bees Trigona that steal nectar from hummingbird flowers. Here we document both interference and exploitative competition between bees and hummingbirds at scarlet, hummingbird pollinated flowers of Passiflora vitifolia. Aggressive stingless bees prevented Long-tailed Hermit Hummingbirds Phaethornis superciliosus from feeding at nearly one-third of the passion flowers approached. In exclusion experiments, bees and hummingbirds each removed most of the nectar from treated flowers. Experimental exclusion of bees also increased hummingbird use of both natural and artificial flowers.     

REGULATION OF THE 24H BODY TEMPERATURE RHYTHM OF WOMEN IN LUTEAL PHASE: ROLE OF GONADAL STEROIDS AND PROSTAGLANDINS

An investigation into whether the rise in the 24h body temperature rhythm observed in the luteal menstrual phase is antagonized by the administration of prostaglandin synthesis inhibitors has been made. Intravaginal body temperature was monitored continuously for 24 h, once in the follicular and twice in the luteal phase. In the luteal phase, women were studied both without and with the simultaneous administration of a prostaglandin synthesis inhibitor (lysine acetylsalicylate; 1.8 g every 6 h orally). The progesterone/estradiol ratio (measured at 17:00h each day) was related to mesor (r=0.825; P<0.001), acrophase (r=0.682; P<0.02), and amplitude (r=?0.731; P<0.001) of the 24h body temperature rhythm. Luteal phase elevation of the progesterone/estradiol ratio was associated with a 0.32±0.07°C increase in mesor (P<0.01), a 0.11±0.02°C decrease in amplitude (P<0.001), and a 34.8±11.6 min delay in acrophase (P<0.03) of the 24h body temperature rhythm. Prostaglandin synthesis inhibitors did not counteract these modifications. The present data shows that the modifications of the circadian parameters of the 24h body temperature rhythm observed during the luteal phase of the menstrual cycle are strictly related to modifications of the progesterone/estradiol ratio, and presumably independent of prostaglandin synthesis.     

THE REGULATION OF PYRUVATE DEHYDROGENASE IN BRAIN IN VIVO

—The activity of pyruvate dehydrogenase in the brains of mice frozen in liquid nitrogen was 14·0 nmol/min per mg protein. It rose to 23·8 nmol/min per mg protein after incubation of the brain homogenate with 10mm -MgCl₂ to activate (dephosphorylate) the enzyme, indicating that approx 60% of the enzyme was originally in the active form. Treatment with amobarbital or pentobarbital halved the proportion of pyruvate dehydrogenase in the active form. The proportion of pyruvate dehydrogenase in the active form increased during ischemia, activation being complete within one min. Anesthesia with amobarbital slowed the activation during ischemia but did not alter the total amount of pyruvate dehydrogenase activity. The concentration of ATP, the ATP/ADP ratio and the adenylate energy charge increased as the proportion of pyruvate dehydrogenase in the active form decreased during barbiturate anesthesia, and they decreased as the proportion of pyruvate dehydrogenase in the active form increased during ischemia. After treatment with insulin, the proportion of pyruvate dehydrogenase in the active form increased by 30%. but the energy charge did not change. Treatment of mice with ether, morphine, ethanol, or diazepam did not change the proportion of pyruvate dehydrogenase in the active form although these treatments have been reported to alter pyruvate oxidation in brain in vivo. Treatments which altered pyruvate oxidation in the brain did not consistently alter the proportion of pyruvate dehydrogenase in the active form, unless they also altered energy charge.     

MUSCARINIC REGULATION OF cAMP IN MOUSE NEUROBLASTOMA

The neurotransmitter acetylcholine regulates cAMP concentrations in mouse neuroblastoma cells (clone NS20). In these cells, the action of acetylcholine appears to be specific: it does not alter basal concentrations of cAMP, but prevents the elevation of cAMP which is mediated by either adenosine or prostaglandin E₁. The receptor for acetylcholine which is involved in this phenomenon has been identified as muscarinic. Pilocarpine and carbamylcholine, but not acetate or choline, will substitute for acetylcholine. Furthermore, the action of 10 μM-carbbamylcholine is blocked by ≥ nM concentrations of atropine, isopropamide or 3-quinuclidinylbenzilate, but not by mM concentrations of d-tubocurarine or hexamethonium. Of eight cholinergic antagonists tested, decamethonium and succinylcholine were the only two which were able to substitute for acetylcholine. These two antagonists are known to cause depolarization of post-synaptic cells. Decamethonium and succinylcholine appear to interact with the same muscarinic receptor, as their actions are also blockèd by low concentrations of 3-quinuclidinylbenzilate. In addition to these two depolarizing antagonists, the ionophores, valinomycin, A23187 and X537A, were also found to prevent elevation of cAMP concentrations. The involvement of specific membrane depolarization as being the active agent by which acetylcholine inhibits elevation of cAMP concentrations is discussed.     

SURROGACY: DONOR CONCEPTION REGULATION IN JAPAN

As of 2008, surrogacy is legal and openly practised in various places; Japan, however, has no regulations or laws regarding surrogacy. This paper reports the situation of surrogacy in Japan and in five other regions (the USA, the UK, Taiwan, Korea and France) to clarify the pros and cons of prohibiting surrogacy, along with the problems and issues relating to surrogacy compensation. Not only in a country such as France that completely prohibits surrogacy within the country, but also in a country such as the UK that allows non‐commercial surrogacy, infertile couples travel overseas for the purpose of surrogacy. In addition, some couples might seek underground surrogacy if the government prohibits surrogacy. If an intended parent couple and a surrogate make an agreement among themselves and then a problem occurs, they cannot ask for support from professionals or bring a case to court, as can be observed in South Korea and Taiwan. We also conclude that there is little difference between commercial surrogacy and non‐commercial surrogacy in the absence of a clear definition of ‘reasonable expenses.’ In the UK, the law does not allow surrogates to receive compensation. However, in reality, there may be little difference between the amounts paid to surrogates for profit in the US and those paid to surrogates for reasonable expenses in the UK. We conclude that the issue of surrogacy demands further discussion in Japan.     

内分泌细胞中溶酶体对激素分泌调节的作用

本实验用外源性雄激素引起垂体促性腺激素细胞和睾丸间质细胞分泌抑制,对这两种细胞中的溶酶体及分泌吞噬和自体吞噬活动进行了超微结构形态观察和半定量分析。实验中应用了CMP酶细胞化学技术和免疫胶体金技术。研究结果显示,在分泌受抑制状态下,垂体促性腺激素细胞中溶酶体增多,分泌吞噬活动加强;与此同时,睾丸间质细胞也表现溶酶体增多、自体吞噬活动加强。这些结果不仅再次证明在分泌蛋白质激素细胞中溶酶体以分泌吞噬的方式参与了激素分泌调节,更重要的是初步证明在分泌类固醇激素细胞的分泌调节中,也有溶酶体的参与,其形式是自体吞噬作用。细胞通过自体吞噬作用得以在短时间内清除一部分合成激素的细胞器和其中的激素,这可能是分泌类固醇激素的细胞及时有效地调整激素分泌量的一项重要机制,与分泌蛋白质激素细胞的分泌吞噬有着相同的意义。