故土·家园·证据

小时候 乡愁是一枚小小的邮票 我在这头 母亲在那头 长大后 乡愁是一张窄窄的船票 我在这头 新娘在那头 后来呵 乡愁是一方矮矮的坟墓 我在外头 母亲却在里头 而现在 乡愁是一湾浅浅的海峡 我在这头 大陆在那头     

海蟾夏眠的代谢生理研究

许多两栖的脊椎动物在干早缺水或者食物不足时埋藏在泥土里休眠。例如,肺鱼能在泥茧里不取食与饮水而生存数年之久(Delaney等,1977),生活在沙漠地带的两栖类能埋藏在沙土里数月以躲避干旱,海蟾(Bufo marinus)能埋藏在沙里克服短时间的缺水,而以露在空气中的鼠孔进行呼吸(Boutilier等,1979)。 海蟾在失水时,经皮肤排出的二氧化碳减少;但是,失水而尚未埋藏在沙里的海蟾,     

稻-麦轮作系统土壤水解酶及氧化还原酶活性对开放式空气CO2浓度增高的响应

研究了FACE条件下(CO2浓度增加200μmol·mol^-1)水稻、小麦不同生育期0～10cm土层土壤脲酶、磷酸酶、芳基硫酸酯酶、脱氢酶活性的变化．结果表明,FACE条件下,土壤脲酶活性在冬小麦生育前期低于对照,在孕穗期高于对照;在水稻生育前期高于对照,在成熟期低于对照．磷酸单酯酶活性在冬小麦生育期高于对照;在水稻分蘖期高于对照,在生育后期(拔节期、抽穗期和成熟期)低于对照．芳基硫酸酯酶活性在小麦越冬期和孕穗期低于对照,在分蘖期和成熟期高于对照;在水稻生育期间均高于对照．脱氢酶活性在小麦和水稻的生育前期低于对照,在后期高于对照．     

雌激素受体α和β亚型在文昌鱼神经系统、哈氏窝和性腺中的定位

用兔抗人ER-α和ER-β多克隆抗体对文昌鱼神经系统、轮器哈氏窝和性腺进行免疫细胞化学的定位研究。结果揭示幼年和成年两性不同发育时期文昌鱼在这些部位分布ER-α和ER-β蛋白。ER-α定位在端脑、中脑、后脑和神经管中大多数神经细胞核,少数在胞质及其突起和神经纤维,ER-β则定位在细胞质或细胞膜上,少数在核内。ER-α免疫阳性物质主要分布在哈氏窝下层的上皮细胞核,少数在上层细胞质,β受体则在上层细胞核。在性腺,ER-α分布在卵巢中卵原细胞和小生长期卵母细胞胞质与核仁,生发泡(核)显免疫阴性,在大生长期卵母细胞核膜和核仁的免疫阳性显著增强,成熟期则在卵细胞生发泡表达;ER-β免疫阳性物质分布在卵原细胞和早期卵母细胞质以及成熟卵细胞的卵被膜检测到,生发泡显免疫阴性。在精巢,这两种ER亚型均定位在精原细胞、初级与次级精母细胞和足细胞质,精子细胞在胞核,精子显免疫阴性。另外,双染结果还揭示ER-α和ER-β在上述部位多数共存于同一细胞,少数在不同细胞表达,且在细胞定位有不同。首次发现这两种雌激素受体亚型在文昌鱼有广泛分布,它们介导雌激素对文昌鱼神经内分泌组织的调节作用。α和β受体在靶细胞定位的不同,提示两者在介导雌激素信号路线和基因转录机制可能有不同生理作用。     

微小RNA ame-miR-31a和ame-miR-13b在意大利蜜蜂哺育蜂和采集蜂脑部的表达差异

【目的】研究微小RNA ame-miR-31a和ame-miR-13b在意大利蜜蜂Apis mellifera ligustica哺育蜂和采集蜂脑部的表达情况,探索其在蜜蜂哺育蜂和采集蜂行为转变中的调节作用。【方法】利用qPCR分别检测ame-miR-31a和ame-miR-13b在意大利蜜蜂工蜂正常蜂群和同龄蜂群中哺育蜂和采集蜂脑部的表达量。【结果】不论在意大利蜜蜂工蜂正常蜂群中还是在同龄蜂群中,ame-miR-31a在哺育蜂脑部的表达量总是显著高于其在采集蜂脑部的表达量;在正常蜂群中,ame-miR-13b在采集蜂脑部的表达量显著高于其在哺育蜂脑部中的表达量;在同龄蜂群中,ame-miR-13b在年老哺育蜂脑部的表达量极显著高于其在同龄采集蜂脑部的表达量,在年轻哺育蜂脑部与同龄年轻采集蜂脑部的表达量差异不显著。【结论】ame-miR-13b在意大利蜜蜂哺育蜂和采集蜂脑部的表达没有明显规律,而ame-miR-31a总是在哺育蜂脑部高表达,提示ame-miR-31a在蜜蜂哺育蜂和采集蜂行为转变中可能发挥重要的调控作用。     

雌激素受体α和β亚型在文昌鱼神经系统、哈氏窝和性腺中的定位

用兔抗人ER-α和ER-β多克隆抗体对文昌鱼神经系统、轮器哈氏窝和性腺进行免疫细胞化学的定位研究。结果揭示幼年和成年两性不同发育时期文昌鱼在这些部位分布ER-α和ER-β蛋白。ER-α定位在端脑、中脑、后脑和神经管中大多数神经细胞核,少数在胞质及其突起和神经纤维,ER-β则定位在细胞质或细胞膜上,少数在核内。ER—α免疫阳性物质主要分布在哈氏窝下层的上皮细胞核,少数在上层细胞质,β受体则在上层细胞核。在性腺,ER-α分布在卵巢中卵原细胞和小生长期卵母细胞胞质与核仁,生发泡(核)显免疫阴性,在大生长期卵母细胞核膜和核仁的免疫阳性显著增强,成熟期则在卵细胞生发泡表达,ER-β免疫阳性物质分布在卵原细胞和早期卵母细胞质以及成熟卵细胞的卵被膜检测到,生发泡显免疫阴性。在精巢,这两种ER亚型均定位在精原细胞、初级与次级精母细胞和足细胞质,精子细胞在胞核,精子显免疫阴性。另外,双染结果还揭示ER-α和ER-β在上述部位多数共存于同一细胞,少数在不同细胞表达,且在细胞定位有不同。首次发现这两种雌激素受体亚型在文昌鱼有广泛分布,它们介导雌激素对文昌鱼神经内分泌组织的调节作用。α和β受体在靶细胞定位的不同,提示两者在介导雌激素信号路线和基因转录机制可能有不同生理作用。     

家蝇3种丝氨酸蛋白酶抑制剂(Serpin)基因在感染白色念珠菌后的表达

研究家蝇丝氨酸蛋白酶抑制剂（ Serpin ）基因 Sp2、Sp13、Sp16 在感染白色 念珠菌后的表达模式。利用白色念珠菌刺激家蝇幼虫,对收集的标本进行逆转录,以 GAPDH 为内参基因,通过qPCR技术检测3条 Serpin 基因在家蝇感染后不同时间点及不同组织中的表达特征,统计分析结果。结果表明,不同时间点感染组和对照组比较, Sp2 mRNA在3 h、6 h和48 h的表达量比对照组高; Sp13 mRNA在6 h的表达量比对照组高,在3 h和24 h时的表达量比对照组低; Sp16 mRNA在6 h、24 h和48 h时的表达量比对照组高,在36 h时的表达量比对照组低。不同组织中感染组和对照组比较, Sp2 mRNA在3 h时,在血淋巴和脂肪体中的表达量比对照组高,在马氏管、气管和肠道的表达量比对照组低;12 h时,在血淋巴中的表达量比对照组高,在马氏管和唾液腺中的表达量比对照组低;24 h时,在脂肪体中的表达量比对照组低;48 h时,在血淋巴中呈高表达,在唾液腺中的表达量比对照组低。 Sp13 mRNA在3 h时,在唾液腺和脂肪体中的表达量比对照组高,在马氏管、体壁、血淋巴和气管中的表达量比对照组低;12 h时,在血淋巴中呈高表达,在体壁和脂肪体中的表达量比对照组低;24 h时,在血淋巴、气管和唾液腺中的表达量比对照组高,在脂肪体中的表达量比对照组低;48 h时,在马氏管、血淋巴、气管和脂肪体中的表达量比对照组高,在体壁和唾液腺中的表达量比对照组低。 Sp16 mRNA在3 h时,在马氏管和气管中的表达量比对照组低;12 h时,在马氏管和脂肪体中其表达量比对照组低;24 h时,其表达量在马氏管中比对照组高,在脂肪体中比对照组低;48 h时,在血淋巴中呈高表达,而在马氏管中的表达量比对照组低。家蝇3种 Serpin基因在白色念珠菌感染后均呈现出差异性表达,推测 Serpin 基因在家蝇免疫调节中具有协同调节作用。     

Notch信号通路在先天免疫和炎症中的作用

Notch信号通路是高度保守的信号传导途径,在无脊椎动物和有脊椎动物中均有表达,并在发育过程中起着至关重要的作用。在免疫系统中,Notch信号通路在中枢和外周淋巴器官调节T和B细胞的发育。已有研究报道了其在淋巴细胞发育中的作用,但在髓系的发育和功能中作用鲜为人知,尤其在急、慢性炎症中。文章将描述Notch信号通路在先天免疫和炎症反应中起关键调节作用,探讨其在炎症性疾病发病机制和治疗中的潜在作用。     

猛禽中的巨人

世界屋脊西藏称得上鹫之天国:中国有5种鹫,在那儿就有3种分布(其它两种兀鹫,拟兀鹫又叫白背兀鹫,在中国只分布在云南,数量非常少;黑兀鹫在中国分布在江苏、云南、广西等地),而且喜马拉雅兀鹫和胡兀鹫差不多是世界屋脊青藏高原的特有种。秃鹫、喜马拉雅兀鹫和胡兀鹫在西藏都有相当的数量。这一点不仅在中国,就是在全世界也是少见的奇迹。     

三化螟生活习性新情况观察

<正> 资料记载,在广东省广州市、中山县以北地区,三化螟Tryporyza incertulas(Walker)均以老熟幼虫在稻根内越冬,稻草内的幼虫在第二年3月间干死而不能化蛹。笔者在调查中发现,在泉州地区三化螟幼虫可在稻根内越冬,     

Measurement of in situ rates of nitrification in sediment

A method has been developed for the measurement of nitrification rates in intact sediment cores without disturbing the concentration gradients of oxygen and ammonium. N-serve (2-chloro-6-trichloromethyl-pyridine), a specific inhibitor of the autotrophic ammonium oxidation, was injected into a 0–2 cm surface layer of the sediment (20 ppm) and added to the water column of sediment cores (5 ppm). N-serve in these concentrations was sufficient to inhibit nitrification, but did not change the rate of ammonium production or incorporation in sediment suspensions, which were incubated aerobically and anaerobically. The ammonium accumulation in cores injected with N-serve was thus equal to the amount of ammonium which was oxidized to nitrate in the control cores. Nitrification rates were in the range of 0–3 mmol N m^{–2 –1}     

Isolation of influenza viruses in different species of bird in Canada in 1978

As part of the international program on the ecology of influenza virus in animals sponsored by W.H.O., 357 influenza A viruses isolated from 2 293 cloacal samples collected from ducks and other bird species in Eastern Canada during the 1978 season were characterized antigenically. Seven hemagglutinin (Hsw 1, H2, H3, Hav2, Hav4, Hav6, Hav7) and six neuraminidase subtypes (N1, N2, Neq2, Nav1, Nav5, Nav6) in 18 different combinations were found. A comparison with viruses isolated during previous seasons indicates that subtypes do change from year-to-year and from place-to-place. Isolation of few viruses from passerine birds requires additional studies to determine if these species are truly infected with influenza virus in nature. This large reservoir of influenza A viruses circulating at the same time in ducks may well be involved in the appearance of new viruses in other species, including humans.     

Influence of kynurenines in pathogenesis of cataract formation in tryptophan-deficient regimen in Wistar rats

L-Tryptophan (Trp) is an essential amino acid and its deficiency is involved in various pathologies. In this present investigation an attempt was made to study the role of tryptophan and its metabolites in cataract formation in wistar rats. Rats were divided and maintained in 3 groups, Group A--control; Group B--marginal-tryptophan and Group C--Tryptophan-deficient diet for 3 months. Slit lamp microscope observations indicated lenticular opacities in Group-C (tryptophan-deficient) rats. In the rats that were maintained on tryptophan deficient diet, a decrease in protein content, kynurenines, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione-s-tranferase (GSTs) and tryptophan-fluorescence intensities and an increase in lipid peroxidation indicative of oxidative stress have been observed. The above changes were normalized in the rats on supplementation of 0.05% tryptophan (Group-B) in their diets. These results suggest that tryptophan-deficiency in the diet leads to an overall significant decrease in kynurenines and levels of antioxidant enzymes (except SOD) in ocular tissue with a concomitant lenticular opacification. The results suggest that diet with adequate tryptophan has protective influence and is of immense benefit in mitigating the changes that may otherwise contribute to the lenticular opacities.     

国内双歧杆菌制剂预防小儿继发性腹泻临床疗效的Meta分析

目的系统评价国内双歧杆菌制剂临床预防小儿继发性腹泻的效果。方法按照系统评价的要求检索CBMd isc、VIP、CNK I以及万方数据库等,获得18篇符合纳入标准的文献,共计患儿4050例,对其进行M eta分析,并评价M eta分析结果的稳定性和发表偏倚。结果异质性检验χ^2=34.60,P=0.007〈0.05,采用随机效应模型进行M eta分析,合并RR=0.41,95%C I为0.35～0.49,总体效应检验,Z=10.39,P〈0.00001,差异具有非常显著性,固定效应模型RR值和95%C I与随机效应模型完全一致,剔除小样本报道后的合并RR=0.42,95%C I为0.35～0.50,与剔除前的结果基本一致,且本研究的发表偏倚得到了很好地控制。结论从现有的临床证据来看,双歧杆菌制剂能降低小儿继发性腹泻的发生率,对预防小儿继发性腹泻起到了满意的效果。     

Role of clozapine in the occurrence of chromosomal abnormalities in human bone-marrow cells in vivo and in cultured lymphocytes in vitro

Summary Bone-marrow chromosomes were examined from 38 mentally and physically retarded and two psychiatric patients who were being treated with a variety of neuropharmacologic drugs. Twenty of these patients used clozapine (Leponex^®). The clastogenic effects of clozapine in vitro were studied in the lymphocyte cultures of three patients-one free of hematologic disease and two who 6 months earlier had had agranulocytosis attributed to the use of clozapine. The mean frequency of cytogenetic abnormalities in the bonemarrow cells of patients who used clozapine was significantly increased (P> 0.05). The two patients who had had agranulocytosis had a greater frequency of cytogenetic abnormalities in their cultured lymphocytes in vivo and in vitro than the patient free of hematologic disease. A clone with a 13/14 chromosome translocation was detected in one of the patients. As all patients received a number of drugs during the in vivo and in vitro studies no definite conclusions could be drawn regarding the role played by clozapine in the occurrence of chromosomal abnormalities.     

我国蝴蝶产业发展中亟待解决的几个问题

本文简略介绍了我国目前蝴蝶产业的背景情况和发展现状,着重阐述了该产业发展中亟待解决的目标与思路、政策与法律、科研与技术、人才与培养等一系列问题,并针地性提出了相应解决意见。     

Role of telomerase in reactivation of macrophage nuclei in heterokaryons

It was shown that the duration of stay of macrophages in the peritoneal cavity of mice and method of their isolation did not affect markedly their capacity for resumption of DNA synthesis in heterokaryons. This means that mouse macrophage undergo such changes during differentiation that reactivation of DNA synthesis in their nuclei is only possible after interaction of telomeres with telomerase, since it was already shown that telomerase was involved in reactivation of DNA synthesis in the macrophage nuclei. The results of experiments did not reveal differences in the length of telomeres in mouse macrophages and other somatic cells. This could depend on the significant length of mouse telomeres and, as a result, their shortening, sufficient for the inhibition of proliferation, is beyond the limits of sensitivity of the current methods. It is also possible that changes in DNA properties in the macrophages occurring during their differentiation depend on changes in the conformation of the telomere complex in these cells. Testing of this suggestion is relevant with respect to recent data that cell hybridization, specifically in the form of heterokaryons, may be essential in realization of the therapeutic effect caused by the introduction of cells during cell therapy.     

Involvement of gonadotropins in induction of luteolysis in pigs

In our previous study we have demonstrated that treatment of endometrial explants with LH increased 13,14-dihydro-15-ketoprostaglandin F(2alpha) (PGFM) accumulation in pigs. This was particularly visible on Days 14-16 of the estrous cycle. Action of gonadotropin in porcine endometrium appears to be mediated by LH/hCG receptors whose number is dependent on the day of the estrous cycle. In the current study i.v. infusion (1 hour) of hCG (200 IU) performed on Days 10 (n=4) and 12-14 (n=4) of the porcine estrous cycle did not affect plasma PGFM (ng/ml+/-SEM) concentrations. In contrast, administration of hCG on Days 15-17 produced, depending on plasma PGFM level before the infusion period, three different types of response: I. plasma PGFM surge of amplitude 0.62+/-0.15 was observed when the mean basal pre-infusion PGFM plasma level was 0.23+/-0.05 (n=6 gilts); II. the delayed PGFM surge of amplitude 0.62+/-0.15 was determined when basal pre-infusion PGFM level was 0.80+/-0.20 (n=6); and III. lack of PGFM response to hCG was found when basal pre-infusion PGFM level was 1.09+/-0.61 (n=6). Concentrations of plasma PGFM before and after saline infusion did not differ on Days 12-14 and 16 of the estrous cycle. In the next experiment blood samples were collected every 1 hour on Days 12-19 of the estrous cycle to determine concentrations of LH, PGFM and progesterone in four gilts. In particular gilts, plasma peaks of LH closely preceded surges of PGFM in 72.7, 84.6, 75.0 and 66.6 percent, respectively. The highest PGFM surges followed a decline in plasma progesterone concentration. We conclude that the increased PGF(2alpha) metabolite production after hCG infusion during the late luteal phase of the estrous cycle as well as the relationship between plasma LH and PGFM peaks suggest the LH involvement in the elevation of endometrial PGF(2alpha) secretion in pigs, and, in consequence, induction of luteolysis.     

Involvement of nitric oxide in inflammation of ovaries in gilts

NADPH-diaphorase (NADPH-d) and an inducible type of nitric oxide synthase (iNOS) were demonstrated in porcine ovaries after unilateral infusion of bacteria into the hilus of an ovary. In group I one ml of saline was infused into the hilus of each ovary from the 15th day to the 19th day of the estrous cycle. In group II one ml of bacterial suspension (10(9) colony forming units of Escherichia coli, Staphylococcus aureus and Corynebacterium pyogenes, in a proportion 1:1:1, respectively) in saline was infused into the hilus of one ovary on days corresponding to those of the control group (gr. I), whereas saline was infused into the contralateral ovary. The ovaries were collected on the 7th day of the next estrous cycle. In the bacteria-treated ovary, the activity of NADPH-d was higher in the endothelium of blood vessels, corpora lutea and follicular walls in comparison to that observed in the respective structures of the contralateral ovary. The highest activity of NADPH-d was found in the vascular endothelium in the bacteria-infused ovary. Vascular smooth muscle cells found in both ovaries of the bacteria-treated gilts were more intensely stained for NADPH-d than those in control animals. After bacteria administration, the intensity of NADPH-d reaction in all the structures of both ovaries in group II was higher than in control group. The strongest immunostaining for iNOS was observed in all structures of the bacteria-infused ovary. In the contralateral ovary, iNOS-immunoreactivity was weaker but still stronger than that in control group. The present results revealed that infusions of bacteria into the hilus of one ovary enhanced the activity of NADPH-d and immunoreactivity for iNOS in both porcine ovaries. However, the activity of both enzymes was higher in the bacteria-infused ovary than in the contralateral one. These data suggest that locally synthesized NO can mediate an inflammatory effect of bacteria in the porcine ovaries.     

Role of Musclin in the Pathogenesis of Hypertension in Rat

Musclin is a novel skeletal muscle-derived secretory factor found in the signal sequence trap of mouse skeletal muscle cDNAs. Musclin possesses a region homologous to the natriuretic peptide family. Thus, musclin is found to bind with the natriuretic peptide clearance receptors. However, the role of musclin in vascular regulation remains unclear. In this study, we aim to investigate the direct effect of musclin on vascular tone and to analyze its role in hypertension using the spontaneously hypertensive rats (SHR). In aortic strips isolated from SHR, musclin induced contractions in a dose-dependent manner. We found that the musclin-induced vasoconstriction was more marked in SHR than in normal rats (WKY). Moreover, this contraction was reduced by blockade of natriuretic peptide receptor C using the ab14355 antibody. Therefore, mediation of the natriuretic peptide receptor in musclin-induced vasoconstriction can be considered. In addition, similar to the natriuretic peptide receptor, expression of the musclin gene in blood vessels was higher in SHR than in WKY. Injection of musclin markedly increased the blood pressure in rats that can be inhibited by anti-musclin antibodies. Musclin-induced vasoconstriction was more pronounced in SHR than in WKY as in its expression. Taken together, these results suggest that musclin is involved in blood pressure regulation. The higher expression of musclin in hypertension indicates that musclin could be used as a new target for the treatment of hypertension in the future.