大鼠侧脑室注射神经降压素对血压的作用

雄性Ｓｐｒａｇｕｅ－Ｄａｗｌｅｙ大鼠,用乌拉坦腹腔麻醉,在侧脑室注射神经降压素（ＮＴ）（１０,２０μｇ）可引起血压升高或降低,心率减慢,预先ｉｃｖ ａ１受体阻断剂哌唑嗪,可阻断ＮＴ的中枢升压反应,预先ｉｃｖ Ｍ受体阻断剂硫酸阿托品,可阻断ＮＴ的中枢降压反应,预先ｉｃｖ Ｈ１受体阻断剂扑尔敏或Ｈ２受体阻断剂甲氰咪胍,对ＮＴ的中枢心血管效应均无明显影响。实验结果表明：脑中ＮＴ升高可使血压升高或降低;在     

侧脑室注射血管紧张素Ⅱ对大鼠血压和缰核内神经元电活动的影响

实验观察了侧脑室注射（ｉｃｖ）及缰核（ｈａｂｅｎｕｌａ ｎｕｃｌｅｕｓ）内微电泳血管紧张素Ⅱ（ＡⅡ）与「Ｓａｒ＾１,Ｔｈｒ＾３」－ＡⅡ（ＳＴ－ＡⅡ,ＡⅡ拮抗剂）对正常和诮激性高血压（ｓｔｒｅｓｓ－ｉｎｄｕｃｅｄ ｈｙｐｅｒｔｅｎｓｉｏｎ ＳＩＨ）大鼠血压及内外侧缰核（ＭＨｂ、ＬＨｂ）内心血管神经元入电活动的影响。结果如下：ｉｃｖ ＡⅡ或ＳＴ－ＡⅡ,正常鼠和ＳＩＨ大鼠血压均升高或降低,ＳＩＨ鼠较正常     

延髓头端腹外侧区─交感缩血管神经系统介导岛皮层升压反应

乌拉坦麻醉、箭毒制动的大鼠在人工呼吸维持下，将谷氨酸钠（Ｇｌｕ）注入岛皮层引起血压升高、心率加快；而岛皮层周围区注入Ｇｌｕ或岛皮层内注入生理盐水对血压和心率无明显影响。双侧延髓头端腹外侧区（ＲＶＬ）内分别注入酚妥拉明、心得安或阿托品均可削弱兴奋岛皮层引起的升压反应，ｉ．ｖ．酚妥拉明也有这削弱的效应，但ｉ．ｖ．心得安或甲基阿托品则无明显作用。上述结果表明岛皮层引起的升压反应是由ＲＶＬ（α－，β－和Ｍ－受体）－交感缩血管神经系统介导的。     

组胺H_1受体激动剂PEA抑制胃酸分泌效应的中枢机制

本文分析了中枢注射ＰＥＡ抑制胃酸分泌效应的脑内过程。雄性Ｗｉｓｔａｒ大鼠,摘除双侧肾上腺,用３７℃的生理盐水通过恒流泵进行连续胃液流。第三脑室给药,观察其对五肽促胃液素（１６０μｇ／ｋｇ,ｓ．ｃ．）诱导的胃酸分泌的影响。结果如下：（１）预先脑室注射抗ＣＲＦ血清（２．５μｌ,１：２００００）可阻断１ＯμｇＰＥＡ的中枢抑酸效应;（２）分别脑室给予ＣＲＦ（１．０和２．０μｇ）和β－内啡肽（０．９４和１．２５μｇ）均明显抑制胃酸分泌;（３）预先注射纳洛酮（５．０μｇ,ｉ,ｃ．ｖ,）可取消ＣＲＦ（１．０μｇ）的中枢抑酸效应,而预先注射抗ＣＲＦ血清（２．５μｌ）对β－内啡肽（０．９４μｇ）的中枢抑酸效应无明显影响。结果提示：ＰＥＡ可能首先引起ＣＲＦ释放,后者再刺激内源性阿片肽释放,从而导致迷走介导的胃酸分泌抑制效应。     

脑室注射GABA对小鼠盐酸诱导型胃溃疡的抑制效应

小白鼠脑室注射ＧＡＢＡ（２、４、６μｍｏｌ）对盐酸诱导型胃溃疡产生一种明显的剂量－效应依赖的抑制效应，腹腔注射ＧＡＢＡ（１００μｍｏｌ）对盐酸诱导型胃溃疡无影响，荷包牡丹碱（ｉ．ｃ．ｖ．０．２μｍｏｌ）、β－氯苯氨丁酸（ｉ．ｃ．ｖ．４μｍｏｌ）或荷包牡丹碱（ｉ．ｃ．ｖ０．２μｍｏｌ）加β－氯苯氯丁酸（ｉ．ｃ．ｖ．４μｍｏｌ）对盐酸诱导型胃溃疡均无影响，但荷包牡丹碱（ｉ．ｃ．ｖ．０．２μｍｏｌ）可以     

脑内P物质在谷氨酸兴奋腹内侧核引起的升压反应中之作用

目的：分析谷氨酸兴奋下兵脑腹内侧核（NVM）引起升压反应的机制。方法：大鼠脑内或静脉注射不同药物,记录血压和心率的变化。结果：①L－谷氨酸（Glu)兴奋NVM、P物质（SP）注入背内侧核（NDM）室旁核（NPV）或延髓头端腹外侧区（RVL）均引起升压反应;②NVM升压反应可被双侧NDM、NPV或PVL内预先注射[D-Pro^2,D-Phe^7,D-Trp^9]-P物质（SP拮抗剂）衰减,但RVL内注射阿托品无此效应;③酚妥拉明（i.v.）也能使NVM升压反应减小,而心得安或甲基阿托品（i.v.）对该升压反应无影响。结论：兴奋NVM可通过NDM（SP受体）,作用于NPV（SP受体）升压区和RVL（SP受体）－交感缩血管神经系统产生升压反应。心交感和心迷走神经不参与该反应。     

柑橘抗寒育种早期鉴定的一种指标

以５个抗寒性不同的柑橘品种或杂交后代：“山金柑”（ＦｏｒｔｕｎｅｌａｈｉｎｄｓｉＳｗｉｎｇｌｅ）、“伏令夏橙”（ＣｉｔｒｕｓｓｉｎｅｎｓｉｓＯｓｂ．ｃｖ．Ｖａｌｅｎｃｉａ）、“伏令夏橙”＋“宁波金柑”（Ｃ．ｓｉｎｅｎｓｉｓｃｖ．Ｖａｌｅｎｃｉａ＋Ｆ．ｃｒａｓｉｆｏｌｉａＳｗｉｎｇ．ｃｖ．Ｍｅｉｗａ）、“Ｐａｇｅ”橘柚（Ｃ．ｒｅｔｉｃｕｌａｔａＢｌａｎｃｏ×Ｃ．ｇｒａｎｄｉｓＯｓｂ．ｃｖ．Ｐａｇｅ）、“Ｍｕｒｃｏｔ”橘橙（Ｃ．ｒｅｔｉｃｕｌａｔａＢｌａｎｃｏ×Ｃ．ｓｉｎｅｎｓｉｓＯｓｂ．ｃｖ．Ｍｕｒｃｏｔ）为材料,研究了低温锻炼期间柑橘原生质体抗寒性的变化及其田间植株的冬季抗寒性,表明离体原生质体抗寒性与田间植株抗寒性之间有显著的正相关,因而前者可以作为衡量后者的指标。     

延髓头端腹外侧区—交感缩血管神经系统介导岛皮层升压反应

乌拉坦麻醇、箭毒制动的大鼠在人工呼吸维持下,将谷氨酸钠注入岛皮层引起血压升高,心率加快,而岛素层周围区注入Ｇｌｕ或岛皮层内注入生理盐水对血压和心率无明显影响,双侧延髓头端腹外侧工内分别注入酚妥拉明,心得安或阿托品均可有弱兴奋岛皮层引起的和或压反应,ｉ．ｖ．酚妥拉明也有这削弱的效应,但ｉ．ｖ。心得安或甲基阿托品则无明显作用,上述表明岛皮层引起的和或压反应是由ＲＶＬ（α－,β－和Ｍ－受体）－交感缩血管     

脑内血管紧张素Ⅱ系统在穹窿下器升压反应中的作用

文献报道脑内存在血管紧张素Ⅱ系统。与此一致,本工作用氨基甲酸乙脂麻醉、箭毒制动、人工呼吸的大鼠观察到：（１）穹窿下器（ＳＦＯ）、室旁核（ＮＰＶ）或ＮＰＶ的投射区：延髓头端腹外侧区（ＲＶＬＭ）、导水管周围灰质（ＰＡＧ）、蓝斑（ＬＣ）内注入血管紧张素Ⅱ（ＡⅡ）均引起升压反应;（２）ＳＦＯ升压反应可被双侧ＮＰＶ或ＲＶＬＭ内预先注入［Ｓａｒ１,Ｔｈｒ８］ＡⅡ（ＳＴＡⅡ,ＡⅡ拮抗剂）明显衰减,ＮＰＶ升压反应也可被ＲＶＬＭ内注入ＳＴＡⅡ削弱;（３）双侧ＰＡＧ用ＳＴＡⅡ预处理后,ＡⅡ引起的ＮＰＶ或ＳＦＯ升压反应均明显减小;（４）ＮＰＶ升压反应还可被双侧ＬＣ内预先注射ＳＴＡⅡ衰减,但ＳＦＯ升压反应不受影响。结合我们以往工作曾显示兴奋ＰＡＧ或ＬＣ均可作用于ＲＶＬＭ引起升压反应,目前的结果表明：ＳＦＯ内的ＡⅡ能神经元通过ＮＰＶ内ＡⅡ能神经元,不仅可直接作用于ＲＶＬＭ引起升压反应,而且还可间接通过ＰＡＧ作用于ＲＶＬＭ起升压作用,但ＬＣ不参与ＳＦＯ升压反应。     

侧脑室内注射五肽胃泌素对大鼠血压和心率的影响

以动脉血压和心率作为指标,在氨基甲酸乙酯麻醉、三碘季铵酚制动、呼吸机控制呼吸的ＳＤ大鼠上,观察到侧脑室内注射五肽胃泌素（Ｇ５,４μｇ）后动脉血压升高,３ｍｉｎ时达峰值,由给药前的１２．２±１．５ｋＰａ增至１４．６±１．６ｋＰａ;心率增加,其最大值由给药前的４３５±５３．９次／ｍｉｎ,增至４７１．６±５３．２次／ｍｉｎ。而侧脑室注射生理盐水（ｐＨ和容积与Ｇ５相同）或静脉注射同剂量的Ｇ５,对上述指标均无影响。侧脑预先注射α受体阻断剂酚妥拉明（１０μｇ）,可部分桔抗Ｇ５对血压和心率的增加效应;而侧脑室预先注射β受体阻断剂心得安（４μｇ）或侧脑室预先注射Ｍ受体阻断剂阿托品（４μｇ）对Ｇ５的血压和心率增加效应均无影响。结果表明：Ｇ５具有中枢性升高动脉血压和心率的作用,此作用可能部分由脑内α受体介导。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.