稻茎毛眼水蝇幼虫田间分布型及抽样技术

根据14丘稻田稻茎毛眼水蝇幼虫调查资料．对其幼虫分布型进行了分析。结果表明;用I、CAm／m、Iσ四种聚集指标法测定,64．3％的田块呈随机分布．28．4%为均匀分布．7．3%为聚集分布。用Iwao平均拥挤度和Taylor幂法则测定．其田间分布型符合随机分布。用频次拟合法测验,50%的田块同时符合渡松、奈曼和负二项分布三种分布型;35．7%的田块同时符合2种分布型。根据该虫田间分布型的特点．制定了相应的序贯抽样技术。     

远交系小鼠胚胎干细胞系的建立及嵌合鼠的获得

ＥＳ细胞（ＥｍｂｒｙｏｎｉｃＳｔｅｍＣｅｌｌｓ）是来源于小鼠早期胚胎的多潜能干细胞,它可以在体外大量培养。并以单细胞的形式注射到早期胚胎里,发育为嵌合体。到目前为止,通常使用的１２９小鼠品系是来源于近交系（ｉｎｂｒｅｄ）小鼠的胚胎．与之相比,远交系小鼠应当具有较强的生命力和抗病能力。曾有人报道过建成了远交系小鼠胚胎干细胞系,但是尚没有见到获得嵌合鼠的报道。有人甚至认为：由于不同品系小鼠所具有的遗传背景不同,有的小鼠不能建成ＥＳ细胞系。最近,本实验室在这方面做了有益的探索,成功地建成了远交系小鼠胚胎干细胞系,并在这里报导首例用远交系小鼠胚胎干细胞系培育成功嵌合体小鼠。采用源于Ｓｗｉｓｓ小鼠远交群的昆明（ＫＭ）品系小鼠囊胚建成了三个小鼠胚胎干细胞系（ＫＥ１．ＫＥ２．ＫＥ５）。核型正常率均达到７０％以上。自第八代起分批冻存,复苏后,培养至第１２代,消化成单细胞,通过囊胚显微注射,将其注射到６１５品系小鼠胚胎。在幸存的幼鼠中获得了一只来源于ＫＥ１细胞的嵌合鼠（Ｔａｂｌｅ１）．其毛色表现为受体鼠（６１５）的白色中嵌合有供体鼠（ＫＭ）的黑褐色（ＰｌａｔｅＩ－Ａ）．嵌合鼠与受体鼠的杂交后代鼠中仍然出现了受体鼠的毛色类型（     

The efficiency of patch sampling for determination of relative tick burdens in comparison with total tick counts

Quanttative data on host tick burdens ar fundamental for the initiation of control strategies and effective management of wildlife populations, but the methods of live sampling employed for domestic animals are unsuitable for sampling wild animals. Despite advances in the use of destructive methods (the scrub and digestion techniques) to obtain measures of the total tick burden on wildlife, these methods are too involved for many field workers, who often need only measures of relative tick burden. Recently, patch sampling methods have been introduced whereby only certain predilection sites are sampled, the presumption being that the number of ticks collected gives an indiccation of the relative degree of infestation. We examined the validity of patch sampling as a measure of relative tick burden by comparing adult ticks collected from the ears, head, neck, foreleg and perianal region of impala (aepyceros melampus) with total tick burdens of the same animals derived from the digestion technique. Adult ticks from patch sampling were positively and significantly correlated with total adults and total ticks (larvae, nymphs, and adults) on impala, with ticks patch sampled from the neck showing the highest correlation with the total tick burden. Comparison of relative tick loads from patch sampling with absolute tick loads from digestion for three classes of impala (females, bachelor males and territorial males) gave qualitatively similar results. We conclude that, when measures of relative tick load are sufficient and destructive sampling is not feasible, patch sampling can provide reliable information on relative tick burdens that are positively correlated with the total tick burden.     

Enhanced early detection and enumeration of zebra mussel (Dreissena spp.) veligers using cross-polarized light microscopy

Zooplankton with calcareous skeletons are birefringent under cross-polarized light, and thus this technique can be quite useful, indeed sometimes almost essential, for the detection and enumemeration of these types of organisms in plankton samples. A simple and inexpensive application of this technique is described and illustrated with quantitative examples from research on the veligers of the zebra mussel Dreissena polymorpha (Pallas). The time required to detect veligers in plankton samples was decreased by an order of magnitude; the accuracy of counts was substantially improved (15% more than controls), and the time required for counts was greatly reduced (41% of control times). This technique is especially useful in situations in which veligers are difficult to find or see (e.g., at low densities, in samples cluttered with extraneous organisms or material) or when the investigator is inexperienced with plankton sampling and planktonic organisms. The major limitations are its inability to discriminate among various bivalve species that have planktonic larvae and the similar appearance of ostracods which also have calcareous shells. Expanded use of this technique should (1) increase our ability to use plankton sampling for the early detection of veligers during range expansion and reproductive cycles and (2) permit more accurate estimates of veliger abundance.     

一种水稻卷叶性状的遗传分析

对水稻卷叶品种流岗卷叶粳与4个平展叶品种及1个卷叶标志基因(rl3)系的杂交或回交后代进行了考察。结果表明,流岗卷叶粳的卷叶特性以单基因不完全显性方式遗传; 该基因与rl3基因不等位,当rl3位点处于隐性纯合时两者以累加方式发生互作。这一等位基因可作标志基因使用,暂定名为Rl(t)。 Abstract:Liugangjuanyejing is a rolled leaf mutant of rice.A genetic study on the rolled-leaf character was carried out by crossing it with four flat-leaf cultivars and a genetic marker line (with a rolled-leaf allele rl3).The results showed that this character was controlled by an incomplete dominant gene which was non-allelic to rl3 locus and that there existed additive effect between the two loci when the rl3 locus was homozygous recessiveness.This new rolled-leaf allele was provisionally named as Rl(t) and could be used as a genetic marker of rice.     

Cervex brush versus vaginal–cervical–endocervical (VCE) triple smear techniques in cervical sampling

Cervex brush versus vaginal–cervical–endocervical (VCE) triple smear techniques in cervical sampling
Cervex brush sampling was compared with the conventional triple vaginal–cervical–endocervical (VCE) smear technique. Nine hundred and fifty‐nine Cervex brush smears and 1064 VCE smears were studied. All smears with both methods were technically satisfactory for evaluation. Endocervical cells were found in 90.7% and metaplastic cells in 73.3% of Cervex brush samples and in 92.5% and 64.1% of VCE samples, respectively. There were significantly more metaplastic cells in smears from premenopausal women. Low grade squamous intraepithelial lesion (SIL) was found in three Cervex brush samples and in two VCE samples. High‐grade SIL was found only in one Cervex brush sample. Benign cellular changes were found in 142 Cervex brush samples and in 144 VCE samples. Sampling with the Cervex brush is efficient, simple and fast and gives high quality cervical smears for cytological evaluation.     

Effect of Calcitriol in Combination with Corticosterone, Interleukin-1β, and Transforming Growth Factor-β1 on Nerve Growth Factor Secretion in an Astroglial Cell Line

Abstract: In astrocytes, nerve growth factor (NGF) synthesis has been described to be stimulated by the cytokines interleukin-1β (IL-1β) and transforming growth factor-β1 (TGF-β1) and inhibited by corticosterone. As all three factors are present in the brain under certain conditions, we investigated the effect of their combined application on NGF secretion in the astroglial cell line RC7 and, in addition, studied the effect of calcitriol (1α,25-dihydroxyvitamin D₃). Calcitriol stimulated NGF secretion, whereas corticosterone reduced basal levels of NGF secretion as well as inhibited the NGF secretion induced by IL-1β, calcitriol, and TGF-β1. Calcitriol had an additive effect when applied together with IL-1β and a synergistic effect when applied with TGF-β1. Moreover, calcitriol not only counteracted the inhibitory effect of corticosterone on NGF secretion stimulated by TGF-β1 but even augmented it to a level more than threefold higher than that reached with TGF-β1 alone. Due to the trophic effect of NGF on basal forebrain cholinergic neurons, these findings might be of therapeutic relevance under conditions where cholinergic function is impaired and the endogenous levels of corticosterone, IL-1β, or TGF-β1 are elevated.     

广西九万山藓类植物区系分析及其对划分热带,亚热带分界线的意义

九万山位于广西北部的中央(25°10’～25°25’N,108°27’E),界于泛北极植物区和古热带植物区的交汇处。其主要植被为亚热带常绿阔叶林。最高海拔为1693m,最低处仅170m。经对1850号标本的鉴定,共计有藓类植物35科、101属和189种。本文分析了九万山的藓类植物区系成分,将其划分为 10种类型。其中东亚成分最为丰富(39.33％),热带、亚热带成分次之(38.20％),而温带成分居第三位(18.54％)。本文选择了九万山临近的五个地区加以比较。其中,金佛山与九万山藓类植物的属和种的相似性系数分别为60.68％和36.87％,神农架为57.29％和33.13％。尖峰岭为48.83％和22.29％,西双版纳为57.29％和29.63％。而我国东部的武夷山则为69.86％和39.57％,其相似性系数在相比较的五个山区中为最高。九万山区有4个特有属并明显受喜马拉雅的影响。特别值得注意的是,在九万山区藓类区系中约有7％的种类是典型的热带成分。根据定量和定性的分析,笔者认为九万山的藓类区系表现出由热带向亚热带过渡的特性,其分界线可能位于九万山的南侧。     

Establishment and characterization of a new,spontaneously immortalized,pancreatic ductal cell line from the Syrian golden hamster

Spontaneously immortal pancreatic cell lines are not available. By use of a defined culture medium, such a line (TAKA-1) was established from the Syrian golden hamster. Cytological, cytogenetic, molecular biological, enzymatic and receptor patterns as well as antigenicity were studied and were compared with those of the normal hamster pancreatic ductal cells in vivo. TAKA-1 cells grew exponentially in a monolayer on collagen gel in a defined medium but did not proliferate in soft agar. Ultrastructurally, the cells closely resembled the normal hamster pancreatic ductal cells. Similarities and dissimilarities were found between the normal ductal cells and TAKA-1 cells. Similarities included the presence of cytokeratin, carbonic anhydrase and some tumor-associated antigens. However, unlike the normal ductal cells, TAKA-1 cells expressed blood group A angigen and anti-vimentin, showed affinity to selected lectins, and an abnormality of chromosome 3, which is suggested to be associated with immortality. Moreover, unlike the hamster pancreatic ductal cancer cells but like the normal hamster pancreatic ductal cells, TAKA-1 cells did not have a c-Ki-ras mutation. EGF, TGF- and secretin, but not CCK or GRP, bound to the TAKA-1 cells. TAKA-1 cells produced TGF-, and their growth was stimulated by exogenous EGF in serum-free medium. This cell line presents a suitable model for biologic and pathologic study of the hamster pancreatic ductal cells in vitro.