VITAMIN A RECEPTORS: MULTIPLE SPECIES IN RETINA AND BRAIN AND POSSIBLE COMPARTMENTALIZATION IN RETINAL PHOTORECEPTORS

Abstract— As assessed by sucrose density gradient ultracentrifugation, bovine retinal cytosol exhibits 2S and 7S vitamin A binding species ('receptors'). Upon fractionation of the retina, outer segment photoreceptor units are enriched in 7S receptor whereas the outer segment poor layers of the retina have a decreased amount of 7S receptor. The 2S vitamin A receptor is found both in the photoreceptor fraction and in the rod-poor layers of the retina. The supernatant fraction of fetal retina demonstrates 2S binding but no 7S binding; a small 7S peak observed in adult pigment epithelial supernatant preparations is also not seen in the supernatant fraction of fetal pigment epithelial cells. The binding pattern in the newborn retina is similar to that in adult retina, i.e. extensive 7S as well as 2S binding. Adult bovine brain exhibits a large 7S receptor peak which is missing in fetal brain supernatant and virtually absent in newborn brain. The 7S receptor may thus be compartmentalized in retinal photoreceptors but is not unique to the retina since it is also observed in brain. The ontogenic patterns in the two tissues are different however.     

唾液中人类疱疹病毒7型的分离与培养

目的：了解人群中人类疱疹病毒7型（HHIV－7）的感染情况,并对HHV－7进行分离培养、鉴定。方法：以聚合酶链反应（PCR）检测唾液中的HHV－7,再以巢式PCR及酶切加鉴别;分离其中2例标本中的病毒,以人脐带血单个核细胞（HCBMC）进行培养,再通过DNA序列测定来鉴定培养结果。结果：检测120例唾液标本有97例阳性,PCR阳性结果示186bp处有一荧光带,经ECORI酶切后成为126bp和60bp两条荧光带,巢式PCR结果示94bp处有一荧光谱,HCBMC可用于HHV－7的传代培养,唾液中分离的HHV－7与培养结果所测得的病毒序列一致。与Berneman分离测得的JI株结果相似,结论：人的唾液中HHV－7检出率高,HHV－7可在HCBMC中增殖。     

SPHINGOLIPIDS AND PHOSPHOLIPIDS IN MICROSOMES AND MYELIN FROM NORMAL AND PATHOLOGICAL BRAINS

—Myelin and microsomes were separated from human cerebral white matter and cortex respectively using the technique of 15% caesium chloride and their sphingolipid and phospholipid contents estimated. Normal brains as well as cerebral material from cases of metachromatic leucodystrophy, Krabbe's disease and Tay-Sachs’disease were studied. Gangliosides were not present in normal myelin but were found in microsomes and in myelin from the pathological material. The ratio of cerebroside to sulphatide in myelin was 4 to 1 in normal, 1 to 20 in metachromatic and 7 to 1 in Krabbe's disease. The results in the human material are briefly discussed.     

SYNTHESIS AND BASE PAIRING PROPERTIES OF 9-DEAZAPURINE N7-NUCLEOSIDES IN OLIGONUCLEOTIDE DUPLEXES AND TRIPLEXES

The 9-deazaguanine N⁷-2′-deoxyribofuranoside (3) as well as the bromo and iodo derivatives 4a,b were synthesized and incorporated in oligonculeotide duplexes and triplexes. Their base pairing properties were investigated and compared with those of the parent purine N⁷-2′-deoxyribofuanosides.     

土人参的组织和单细胞培养及试管苗开花结实

以土人参的花梗、茎和叶片为外植体在ＭＳ培养基上诱导出愈伤组织,诱导率为７５％－９０％。愈伤组织经分化和生根培养再生了完整植株。由组织培养再生苗的幼茎诱导的愈伤组织建立悬浮系。由悬浮系分离的单细胞在２／３ＭＳ液体培养基中振荡培养或振荡培养３周后转入双层培养均再生了愈伤组织,再生率分别为０．２８％和０．４１％。愈伤组织在含有较低浓度６－ＢＡ的培养基上分化出苗。幼苗生长迅速,每３周扩增６．７倍,再生植株     

7-DEAZAPURIN-2,6-DIAMINE AND 7-DEAZAGUANINE: SYNTHESIS AND PROPERTY OF 7-SUBSTITUTED NUCLEOSIDES AND OLIGONUCLEOTIDES

The synthesis of 7-substituted 7-deazaguanine and 7-deazaadenine ribonucleosides 1–2, the incorporation of 3a–d into oligonucleotides, and the stability of the corresponding duplexes and base discrimination are described. The pK_a values of 3–4 are determined.     

大脑前额叶皮层与免疫机能的关系Ⅰ.损毁前额叶皮层对猕猴淋巴细胞免疫机能的影响

用临床细胞免疫学检测方法,对损毁大脑前额叶背外侧部皮层手术前、手术后７天和手术后３０天的猕猴外周血液淋巴细胞的４种免疫花环（Ｅｔ、Ｅａ、ＺＹＣ和ＭＥ花环）进行了跟踪监测,并与假手术组进行对照。结果表明：损毁大脑前额叶皮层后,其外周血活化Ｔ淋巴细胞花环率（Ｅａ）和Ｂ淋巴细胞的小鼠红细胞花环率（ＭＥ）均在手术后７天显著下降;直到手术后３０天仍显著低于手术前。而总Ｔ淋巴细胞花环率（Ｅｔ）和酵母多糖补体复合物花环率（ＺＹＣ）则在手术后７天显著下降,在手术后３０天又回复。这些结果提示：大脑前额叶皮层对机体免疫机能具有一定的调节联系作用,损毁大脑前额叶皮层后,可引起机体淋巴细胞免疫功能下降,其作用机理尚待进一步研究     

真菌菌丝体和发酵液的氨基酸分析比较

<正> 对云芝等7种真菌的菌丝体和发酵液分别测定17种氨基酸的含量,测定结果表明这些菌丝体中含有丰富的人体8种必需氨基酸,支链氨基酸及精氨酸,而芳香族氨基酸和含硫氨基酸却很低。7种真菌的菌丝体和它们的子实体,和三种食用蛋白(α-酪蛋白,卵白蛋白,大豆球蛋白)及4种粮食产品     

噬菌体T7基因6.5和6.7的克隆及其缺失变种的构建

 用适当的限制性内切酶,将噬菌体T7基因6.5和6.7从整个噬菌体T7基因组中分离出来,插入到质粒pBR322中去,转化E.Coli HMS174,筛选出这两个基因的成功克隆。运用同样手段,从整个噬菌体T7基因组中分离出含有部分基因6编码序列,而不含基因6.5和6.7编码序列的T7DNA片段,插入到pBR322的衍生质粒中去,转化Ecoli C1757,再用含有基因6和基因7的双突变噬菌体T7去感染这一转化菌,通过同源交叉而得到缺失基因6.5和6.7的噬菌体T7缺失变种。这种噬菌体只能在载有噬菌体T7基因6.5和6.7,或者只载有基因6.7质粒的寄主中增殖。通过噬菌体结构蛋白电泳分析证明,这种噬菌体丢失了野生型菌体T7所具有的两条结构蛋白带。     

芝田硫化叶菌ssh7a和ssh7b基因在大肠杆菌中的表达及重组蛋白的性质

极端嗜热古菌－－芝田硫化叶菌ＤＮＡ结合蛋白Ｓｓｈ７ａ和Ｓｓｈ７ｂ的编码基因（ｓｓ７α和ｓｓｈ７ь）在大肠杆菌中得到表达。量均达到细胞蛋白总量的１０％￣１５％。重组蛋白通过一个包括热处理步骤的简单纯化程序得到纯化。重组Ｓｓｈ７ａ和Ｓｓｈ７ｂ与松弛及负超螺旋ＤＮＡ的结合与天然Ｓｓｈ７蛋白无异,与天然Ｓｓｈ７相似,Ｓｓｈ７ａ在与ＤＮＡ结合时能免固定负超螺旋,每固定一个负超螺旋约需２２个Ｓｓｈ７ａ分子。这     

8-AZA-7-DEAZAADENINE AND 7-DEAZAGUANINE: SYNTHESIS AND PROPERTIES OF NUCLEOSIDES AND OLIGONUCLEOTIDES WITH NUCLEOBASES LINKED AT POSITION-8

The 8-aza-7-deazaadenine (pyrazolo[3,4-d]pyrimidin-4-amine) N⁸-(2′-deoxy-ribonucleoside) (2) and the 7-deazaguanine (pyrrolo[3,4-d]pyrimidine-2-amin-(3H)-4-one) C⁸-(2′-deoxyribonucleoside) (4) were synthesized and incorporated in oligonucleotides employing phosphoramidite chemistry. Oligonucleotides carrying compound 2 are able to form base pairs with the four canonical DNA constituents without significant structural discrimination. The nucleoside 4 was obtained from the corresponding ribonucleoside by deoxygenation. Oligonucleotides containing compound 4 showed similar base pairing properties as those with 2′-deoxyisoguanosine.     

长春和北京地区引起婴幼儿肺炎的3型与7型腺病毒的分子流行病学研究

对长春和北京地区连续12年(1976年冬至1988年春)引起小儿肺炎的3、7型腺病毒102株标本,进行了限制性内切酶核酸电泳图谱分析。56株7型腺病毒经BamHⅠ、BclⅠ、BglⅠ、XbaⅠ、SmaⅠ、HindⅢ分析后,表现为两个基因组型——Ad7 b和Ad7 d。46株3型腺病毒被Bg1 Ⅱ、BamHⅠ酶解后,表现为 3个基因组型——Ad 3Ⅰ、Ad 3Ⅱ、Ad 3Ⅲ。各基因组型的分布情况是:56株7型腺病毒中,43株为Ad 7 b(76.8％),流行于1976年冬至1986年春;13株是Ad 7 d(23.2％),出现于1982年,与Ad 7 b共同流行;1986年～1988年分析的5株病毒都是Ad 7d。43株3型腺病毒中,Ad3Ⅰ42株(91.0％),分布于12年中;Ad 3Ⅱ、Ad 3Ⅲ各2株,散在分布。此结果表明,国内这12年中引起小儿肺炎的3型腺病毒至少有3个基因组型,7型腺病毒至少有两个基因组型。Ad3Ⅰ和Ad7 b是流行优势基因组型。但自80年代初开始出现Ad7 d以来,有逐年增多的趋势,最近两年的标本又都是Ad7 d,很可能它将取代Ad7 b而成为流行的优势基因组型.     

阿特拉津降解菌株的分离和鉴定

从农药厂废水中分离到6株能以除草剂阿特拉津为唯一氮源生长的细菌,即假单胞菌（Pseudomonas spp,.)AD1,AD2和AD6,土壤杆菌（Agrobacterium sp.)AD4,黄单胞菌（Xanthomonas sp.)AD5,欧氏菌（Erwinia sp.)AD7,AD1菌株能使无机盐培养基中的0．3g/L阿特拉津在72h内降解99．9％,当以AD1,AD2,AD4,AD5,AD6和AD7菌株的总DNA为模板进行PCR扩增时,除AD2菌株以外,均得到了与献报道的假单胞菌ADP菌株的阿特拉津氯水解酶基因（atzA)同源的PCR产物。     

PROPYNYL GROUPS IN DUPLEX,HAIRPIN AND TRIPLEX DNA: 7-DEAZAPURINES AND 9-DEAZAPURINES

Oligonucleotides containing 7-deazapurines or 9-deazapurines with propynyl groups at the 7- or 9-position were prepared. The stabilizing effect of the propynyl group was studied on DNA duplexes, hairpins and triplexes.     

IDENTIFICATION AND PHYLOGENETIC IMPLICATIONS OF FATTY ACIDS AND STEROLS IN THREE GENERA OF AQUATIC PHYCOMYCETES

Allomyces macrogynus, A. arbuscula, A. javanicus, Allomyces male and female hybrid strains, Blastocladia ramosa and Monoblepharella sp. were examined for their fatty acid and sterol compositions by GLC and combined GLC/MS. All the organisms produce a range of fatty acids 12 to 20 carbon atoms in length. Palmitic, stearic, and arachidic acid represent the highest concentrations of saturated fatty acids; oleic, linoleic, and arachidonic acid the highest unsaturated fatty acids. B. ramosa synthesizes only two polyunsaturates, linoleic and linolenic, but Allomyces and Monoblepharella are capable of desaturation as far as arachidonic acid. Cholesterol is produced by all the isolates and is the dominant sterol in Allomyces. 24-Methyl and 24-ethyl derivatives of cholesterol are the dominant sterols of Monoblepharella. B. ramosa contains a more complex sterol mixture representing changes which occur in the formation of cholesterol from lanosterol: 24-dihydrolanosterol, 14α-methyl Δ⁸-cholestenol, Δ⁸⁽⁹⁾-cholestenol, 14α-methyl Δ⁷-cholestenol, Δ⁷-cholestenol and cholesterol. Δ⁷-cholestenol, 24-dihydrolanosterol, and 14α-methyl Δ⁸-choIestenol appear to be the major components. This is the first time that 14α-methyl Δ⁸ and 14α-methyl Δ⁷-cholestenol have been reported as naturally occurring sterols.     

三个新2,2—二甲基苯并二氢吡喃类化合物的分离与鉴定

从中药三叉苦(Evodia lepta(Spreng.)Merr.)的地上部分分离鉴定了4个化合物。通过光谱解析和结构沟通的方法确定了它们的结构。其中3个为新化合物,依次命名为leptin A(Ⅰ)、leptin B(Ⅱ)和leptin C(Ⅲ)。另外一个已知化合物为异吴茱萸酮酚(Ⅳ)。     

采后荔枝果实中氧化和过氧化作用的变化

采后的荔枝（Litchi chinensts)果实的果皮和果汁中的抗坏血酸及果汁的谷胱甘肽含量逐渐下降,果皮的谷胱甘肽甘肽含量先增多（采后3天）接着减少,超氧化物歧化酶活性随采后时间加长而降低,膜脂过氧化产物丙二醛及过氧化物酶活性显著增高,采收7天后果皮中丙二醛含量增加2倍,过氧化物酶活性增高6－7倍,超氧物歧化酶活性只为原来的44％,内源清除活性氧能力的减弱与膜脂过氧化产物的积累表明,荔枝果实的衰老与活性氧的伤害有关,过氧化物酶活性增高可作为果实衰老的一个指标。     

ALKYLATION OF RAT BRAIN NUCLEIC ACIDS BY N-METHYL-N-NITROSOUREA AND METHYL METHANESULPHONATE

Abstract— Alkylation of rat brain nucleic acids in vivo was measured after a single intravenous injection (1 mmol/kg body wt.) of N -[¹⁴C]methyl- N -nitrosourea and [¹⁴C]methyl methanesulphonate. The main product with both compounds was 7-methylguanine, The extents of methylation on this position in DNA and RNA were similar with methylnitrosourea but methyl methanesulphonate produced twice as much 7-methylguanine in DNA as in cytoplasmic RNA. Brain DNA from rats treated with labelled methylnitrosourea contained radioactive O ⁶-methylguanine, accounting for about 12 per cent of the radioactivity present as 7-methylguanine and cytoplasmic RNA contained about half this amount of O ⁶-methylguanine. Neither DNA nor cytoplasmic RNA from methyl methanesulphonatetreated rats contained any detectable O ⁶-methylguanine. Treatment with both compounds resulted in varying small amounts of methylation of other nucleic acid bases including 1-methyladenine, 3-methyladenine and 3-methylcytosine. The possible relevance of alkylation of brain nucleic acids to the induction of brain tumours is discussed.