人胃癌不同周期细胞膜表面ConA受体的分布与侧向运动

本文研究了人胃低分化粘液性腺癌细胞MGC 80-3不同周期时相中ConA受体的分布与侧向运动。MGc 80-3细胞经同步化培养,用F-ConA标记。被标记细胞中G_1、S和G_2期呈不连续的分布,但它们之间又存在显著的差异。M期呈较均匀的强荧光分布(与其它时相细胞比较)。荧光漂白恢复方法测定ConA受体复合物侧向运动表明:各个周期时相之间不仅运动方式不同,而且运动速率也有显著差异。M期与G_1期主要表现出扩散型运动;而S期与G_2期表现为流动型运动。G_1期的扩散系数大干M期的;S期的流动速率大于G_2期的。但可动分子百分比以G_2期最高。这些结果表明了ConA受体的动力学性质。它受到细胞周期的调节。     

小鼠精母细胞联会复合体RNA组分的电镜研究

本文运用常规染色和Bernhard染色方法对切片标本中小鼠粗线期精母细胞联会复合体(SC)的超微结构和电镜细胞化学特点进行了研究。经常规染色后,可见SC由侧生组分(LE)、中央组分(CE)和L-C纤维组成;SC宽约210nm,LE宽约60nm,中央间隔区宽约90nm。在Bernhard染色标本中,SC的LE、CE和L-C纤维着色较深,说明其中含有RNA;SC各结构组分的宽度和形态特点与常规染色标本中的基本一致。本文讨论了SC中存在有RNA等问题。     

New Mechanism of Melanosomes Transport into Hair of Lambs of Different Breeds and Genotypes

By light microscopic investigation of skin and wool specimens of newborn lambs, we discovered a previously unknown mechanism for melanosomes transport in the process of dermal papilla melanocytes regular mitosis and migration into the hair shaft. This mechanism plays a great role in hair pigmentation especially in dominant (E^D/E^D) and recessive (A^a/A^a) black lambs of all investigated breeds. The rate of pigment cell mitosis, proliferation, and migration differs greatly in lambs of investigated color genotypes. In black genotypes the rate of melanocyte mitosis is very high and is approximately the same as in the hair bulb matrix cells, whereas in brown and red genotypes this rate is much lower. Melanocyte mitosis in the light red and tan groups was not found.     

应用酶联免疫吸附试验检测不同类型乙型肝炎中激活补体类HBsAg循环免疫复合物

本文以抗人C_(?)的羊IgG为包被抗体,以HRP-HBs抗体为指示抗体,建立了可检测激活补体类HBsAg循环免疫复合物(HBsAg/C3-CIC)的C_3捕捉法酶联免疫吸附试验。检测了236例六种类型临床诊断为乙型肝炎的病人血清标本,其阳性率分别为:无症状携带者(ASC)12.9％(4/31),急性肝炎(AH)36.7％(22/60),慢性迁延性肝炎(CPH)33.3％(7/21),慢性活动性肝炎(CAH)59.6％(34/57),重型肝炎(SH)77.8％(14/18),肝炎后肝硬化(PLC)67.3％(33/49),阳性率与肝损严重程度明显相关(P<0.01)。认为HBs-Ag/C3-CIC可能在乙型肝炎病毒引起的慢性活动性肝炎、重型肝炎和肝炎后肝硬化的发病过程中起重要作用,并可作为乙型肝炎的诊断、临床分型和预后判断的指标之一。     

Two different sets of cis elements regulate scute to establish two different sensory patterns

Summary We have analysed the role of the achaete-scute gene complex in the development of the pattern of campaniform sensilla on the wing blade of Drosophila. We show that the complete pattern results from the superimposition of two independent subpatterns, one of which depends on the achaete gene and the other on scute. The scute subpattern comprises several clusters of sensilla, most of which seem to require the presence of control regions located upstream of the transcribed region. This is in contrast with the pattern of scute-dependent bristles, most of which depends on control elements located downstream of the transcribed region.     

Interactions Between Calonectria crotalariae and Heterodera glycines on Soybean

The interactions of Heterodera glycines at four egg inoculum levels (0, 100, 1,000, and 10,000 per pot) and three cyst levels (0, 100, and 200 per pot) and Calonectria crotalariae at 500, 5,000, and 50,000 microsclerotia per pot were evaluated on soybean. At the two lowest nematode egg levels, the presence of C. crotalariae did not affect nematode reproduction. At 10,000 eggs per pot, however, nematode reproduction was increased significantly at each microsclerotial level. The increase in nematode reproduction was stepwise at 500 and 5,000 microsclerotia per pot but declined at 50,000 microsclerotia per pot. Similar results were obtained when cysts rather than eggs were used as nematode inoculum. The nematode x fungus interaction significantly affected 60-day plant growth parameters of both Lee 74 and Centennial soybean. The nematode x fungus interaction was antagonistic to plant roots and significantly influenced root injury ratings. The presence of C. crotalariae in tissues of stock plants or plants used as race differentials did not alter the analysis of this population as race 3.     

Regionally selective alterations in enzymatic activities and metabolic fluxes during thiamin deficiency

To further elucidate the molecular basis of the selective damage to various brain regions by thiamin deficiency, changes in enzymatic activities were compared to carbohydrate flux through various pathways from vulnerable (mammillary bodies and inferior colliculi) and nonvulnerable (cochlear nuclei) regions after 11 or 14 days of pyrithiamin-induced thiamin deficiency. After 11 days,large decreases (–43 to –59%) in transketolase (TK) occurred in all 3 regions; 2-ketoglutarate dehydrogenase (KGDHC) declined (–45%), but only in mammillary bodies; pyruvate dehydrogenase (PDHC) was unaffected. By day 14, TK remained reduced by 58%–66%; KGDHC was now reduced in all regions (–48 to –55%); PDHC was also reduced (–32%), but only in the mammillary bodies. Thus, the enzyme changes did not parallel the pathological vulnerability of these regions to thiamin deficiency.¹⁴CO₂ production from¹⁴C-glucose labeled in various positions was utilized to assess metabolic flux. After 14 days, CO₂ production in the vulnerable regions declined severely (–46 to 70%) and approximately twice as much as those in the cochlear nucleus. Also by day 14, the ratio of enzymatic activity to metabolic flux increased as much as 56% in the vulnerable regions, but decreased 18 to 30% in the cochlear nuclei. These differences reflect a greater decrease in flux than enzyme activities in the two vulnerable regions. Thus, selective cellular responses to thiamin deficiency can be demonstrated ex vivo, and these changes can be directly related to alterations in metabolic flux. Since they cannot be related to enzymatic alterations in the three regions, factors other than decreases in the activity of these TPP-dependent enzymes must underlie selective vulnerability in this model of thiamin deficiency.Abbreviations KGDHC 2-ketoglutarate dehydrogenase complex EC 1.2.4.2., EC 2.3.1.61, EC 1.6.4.3. - PDHC pyruvate dehydrogenase complex EC 1.2.4.2., EC 2.3.1.12, EC 1.6.4.3 - TK transketolase (EC 2.2.1.1) - TPP thiamin pyrophosphate     

The effect of glucose on the expression of extracellular protein genes by Staphylococcus aureus strain V8

The bacteria from overnight cultures (20 h) of S. aureus V8 and exp negative mutant K6812-1, grown, aerobically, in 3% (w/v) Tryptone Soya Broth, at 37 degrees C, were resuspended in fresh medium, in the case of the parent strain +/- 1% (w/v) glucose, without change in bacterial density. During a 6 h incubation period there was an approximate doubling of bacterial density, to the same level, in each case. However, exoprotein production by the mutant was only 20% that of the parent whilst the addition of glucose to the V8 strain resulted in a tenfold reduction in the exoprotein formed. SDS-polyacrylamide gel electrophoresis showed that the exoprotein patterns of both organisms after 6 h incubation were the same as those observed in the overnight cultures whilst the presence of 1% (w/v) extra glucose changed the pattern produced by the parent to one similar to that of the mutant. The results showed that conditions which lead to the rapid formation of glucose catabolites produced an effect consistent with the inhibition of the activity of the exp gene product.     

Regulation of the spatial order of cortical microtubules in developing guard cells ofAllium

The organization of microtubules (MTs) in the cortex of cells at interphase is an important element in morphogenesis. Mechanisms controlling the initiation of MTs and their spatial ordering, however, are largely unknown. Our recent study concerning the generation of a radial array of MTs in stomatal guard cells inAllium showed that the MTs initiate in a cortical MT-organizing zone adjacent to the ventral wall separating the two young guard cells (Marc, Mineyuki and Palevitz, 1989, Planta179, 516, 530). In an attempt to detect MT-ordering mechanisms separate from the sites of MT initiation, we now employ various drugs to manipulate the geometry and integrity of the ventral wall and thereby also the associated MT-organizing zone. In the presence of cytochalasin D the ventral wall is tilted away from its normal mid-longitudinal anticlinal alignment, while treatments with the herbicide chloroisopropyl-N-phenylcarbamate (CIPC) induce the formation of a branched ventral wall. Nonetheless, in either case the MTs still form a radial array, although this is asymmetric as it is centered in accordance with the misaligned or branched ventral wall. Since the MTs maintain their original course undisturbed as they extend beyond the abnormal ventral wall, there is no evidence for the presence of an inherent MT-ordering mechanism at locations remote from MT-initiation sites. Following treatments with caffeine, which abolishes the formation of the ventral wall, the MTs revert to a transversely oriented cylindrical array as in normal epidermal cells. Thus the presence of the ventral wall, and presumably also the associated MT-organizing zone, is essential for the establishment of the radial array. The MT-organizing zone is therefore involved not only in the initiation of MTs, but also in determining their spatial order throughout the cell cortex. We thank Drs. Richard J. Cyr and Yoshi Mineyuki for providing valueable suggestions during the course of this work, and Ms. Elizabeth Bruce printing some of the figures. This research was supported by Funds from the National Science Foundation grants DCB-8703292 to B.A.P. and DCB-8803286 to B.A.P. and J.M.