Medical biology最新文献_第5页

Cell interactions in the rat seminiferous epithelium with special reference to the cellular distribution of calmodulin. 大鼠精系上皮细胞间的相互作用与钙调蛋白的细胞分布。

Medical biology Pub Date : 1986-01-01

P Mali, M J Welsh, J Toppari, K K Vihko, M Parvinen

{"title":"Cell interactions in the rat seminiferous epithelium with special reference to the cellular distribution of calmodulin.","authors":"P Mali, M J Welsh, J Toppari, K K Vihko, M Parvinen","doi":"","DOIUrl":"","url":null,"abstract":"Spermatogenesis is dependent on stimulation by pituitary gonadotropins, FSH and LH. Targets for these hormones are Sertoli and Leydig cells, respectively. The effect of LH on spermatogenesis is mediated by testosterone. In addition to hormones, interactions between neighbouring cells seem to regulate spermatogenesis. This is reflected by cyclic secretion of several proteins by the seminiferous epithelium, of which plasminogen activator is a good example. While it is controlled by FSH a factor in preleptotene spermatocytes may also influence its cyclic secretion pattern. Both testosterone and FSH have a cyclic action in the seminiferous epithelium. The androgens seem to predominate in stages where spermiation, onset of meiosis and the highest rate of RNA transcription occur (VII-XI). FSH is most active in stages that contain meiotic divisions and early spermiogenesis (XIII-V), greatly stimulating the production of cyclic AMP. To investigate further the \"second messengers\" of FSH action in the seminiferous epithelium, the cellular distribution of calmodulin was analyzed using an indirect immunocytochemical method. In addition to their clear cyclic distribution in primary spermatocytes and in spermatids, Sertoli cells also showed a bright calmodulin immunofluorescence that was apparently cyclic. These observations suggest a local calmodulin and calcium regulation of spermatogenesis.","PeriodicalId":18313,"journal":{"name":"Medical biology","volume":"63 5-6","pages":"237-44"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14216369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Light and electron microscopic immunocytochemistry of proenkephalin-derived peptides in septal neurons. 中隔神经元前脑啡肽衍生肽的光镜和电镜免疫细胞化学。

Medical biology Pub Date : 1986-01-01

L Kivipelto, P Panula

引用次数: 0

Immunocytochemical studies on axonal transport in adrenergic and cholinergic nerves using cytofluorimetric scanning. 利用细胞荧光扫描研究肾上腺素能和胆碱能神经轴突运输的免疫细胞化学。

Medical biology Pub Date : 1986-01-01

A Dahlström, P A Larsson, M Goldstein, K Lundmark, A G Dahllöf, S Bööj

{"title":"Immunocytochemical studies on axonal transport in adrenergic and cholinergic nerves using cytofluorimetric scanning.","authors":"A Dahlström, P A Larsson, M Goldstein, K Lundmark, A G Dahllöf, S Bööj","doi":"","DOIUrl":"","url":null,"abstract":"The axonal transport of adrenergic and cholinergic axonal organelles in rat sciatic nerve has been studied using a cytofluorimetric scanning (CFS) technique. This technique gives quantitative data on material which accumulates in a nerve relative to a crush, as well as morphological and morphometrical information about the accumulated axons in the nerve. One important advantage is that several substances can be measured in the same nerve segment, thus reducing the number of animals needed. The substances must be made fluorescent, and in this study we have investigated noradrenaline (NA), using formaldehyde induced fluorescence, and dopamine beta-hydroxylase (DBH), tyrosine hydroxylase (TH), neuropeptide Y (NPY) and two cholinergic vesicle components (a transmembrane glycoprotein and synapsin I) using indirect immunofluorescence. The antisera used for labelling immunoreactive material (IR) were produced in rabbit or goat (DBH). In adrenergic axons NA, DBH-IR and TH-IR accumulated with time after crushing the nerve as described earlier with biochemical techniques. After reserpine, the amounts of amine granules transported distally in the sciatic nerve initially fell, but recovered during day 2 after reserpine. At day 4 the amount of NA and DBH-IR which was transported distally in the axons was supranormal, 160% and 140% of control, respectively, but the level of NPY-IR was not increased, even falling to subnormal at day 4, indicating different mechanisms for regulating the synthesis of DBH and NPY which are suggested to co-exist in axonal adrenergic large dense core vesicles. In cholinergic motor axons organelles, recognized by rabbit-anti-cholinergic synaptic vesicles-antiserum (RASVA) and by anti-synapsin I-antiserum, are transported distally at a rapid rate.(ABSTRACT TRUNCATED AT 250 WORDS)","PeriodicalId":18313,"journal":{"name":"Medical biology","volume":"64 2-3","pages":"49-56"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14012786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nucleic acid hybridization: from research tool to routine diagnostic method. 核酸杂交:从研究工具到常规诊断方法。

Medical biology Pub Date : 1986-01-01

A C Syvänen

{"title":"Nucleic acid hybridization: from research tool to routine diagnostic method.","authors":"A C Syvänen","doi":"","DOIUrl":"","url":null,"abstract":"The nucleic acid hybridization reaction is extremely specific and thus a valuable tool for the identification of genes or organism of interest. The increasing use of nucleic acid hybridization in applied fields like diagnostic medicine has led to the development of more convenient hybridization assays than those originally used in basic research. In conventional nucleic acid hybridization methods immobilized nucleic acids are detected on a filter by a radiolabelled probe. Sandwich hybridization is a simple test format for the analysis of unpurified biological material, but has the disadvantage of a slow reaction rate. Solution hybridization methods are fast and easy to perform provided that a method to separate the formed hybrids from the reaction mixture is available. In non-isotopic detection the nucleic acid probe is modified with a chemical group, which is identified with a labelled detector molecule after hybridization. The low sensitivity of detection is the main problem in nucleic acid hybridization methods. Procedures to amplify the detectable signal or the amount of detectable nucleic acid sequences are potential solutions to this problem. The new hybridization methods have successfully been used for some applications, but still need to be combined into well performing tests to be applicable to any desired purpose.","PeriodicalId":18313,"journal":{"name":"Medical biology","volume":"64 6","pages":"313-24"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14669168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Acceleration of p-aminohippurate excretion in immature rats by dexamethasone treatment. 地塞米松对未成熟大鼠对氨基马粪酸排泄的加速作用。

Medical biology Pub Date : 1986-01-01

H Bräunlich, A Köhler, I Schmidt

引用次数: 0

Expression of the cell adhesion molecules N-CAM and L1 in B16 melanoma cells. 细胞粘附分子N-CAM和L1在B16黑色素瘤细胞中的表达。

Medical biology Pub Date : 1986-01-01

D Linnemann, E Bock

引用次数: 0

Regulation of primate testicular function by GnRH analogues. GnRH类似物对灵长类动物睾丸功能的调节。

Medical biology Pub Date : 1986-01-01

G F Weinbauer, E Nieschlag

{"title":"Regulation of primate testicular function by GnRH analogues.","authors":"G F Weinbauer, E Nieschlag","doi":"","DOIUrl":"","url":null,"abstract":"The potential of GnRH analogues for regulating testicular function is reviewed. Our experiments showed that constant infusion of GnRH agonists effectively suppressed testicular function in monkeys. In men, however, spermatogenesis could not be suppressed to achieve azoospermia uniformly. GnRH antagonists, although at much higher dosages than agonists, caused a more rapid and uniform inhibition of testis function. Spermatogenesis was reversibly disrupted at the spermatogonial level. Concomitant testosterone supplementation, used to maintain libido and potency, attenuated the antitesticular effects of GnRH analogues. In monkeys testosterone appears to stimulate spermatogenesis directly on the testicular level, while evidence has been obtained that in rats testosterone can also stimulate the release and synthesis of FSH under antagonist mediated blockage of pituitary GnRH receptors. When extrapolating to human studies special care has to be exerted in the selection of testosterone substitution regimens. Although the agonistic and antagonistic analogues of GnRH ultimately exert their antireproductive effects via inhibition of gonadotropin secretion the antagonists may have the greater potential for male fertility regulation due to quicker pituitary and testicular suppression.","PeriodicalId":18313,"journal":{"name":"Medical biology","volume":"63 5-6","pages":"210-7"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14216492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Metabolism and transport of amino acids studied by immunocytochemistry. 免疫细胞化学研究氨基酸的代谢和转运。

Medical biology Pub Date : 1986-01-01

J Storm-Mathisen, O P Ottersen, T Fu-Long, V Gundersen, J H Laake, G Nordbø

{"title":"Metabolism and transport of amino acids studied by immunocytochemistry.","authors":"J Storm-Mathisen, O P Ottersen, T Fu-Long, V Gundersen, J H Laake, G Nordbø","doi":"","DOIUrl":"","url":null,"abstract":"The immunocytochemical method for demonstrating amino acids makes it possible to study accumulation and depletion of amino acids in individual tissue compartments resulting from experimental manipulations. We have incubated hippocampal slices in oxygenated Krebs solution, containing various additives, under basal conditions and during synaptic release of transmitters evoked by elevated K+ concentrations or by veratrine. Immunoreactivities for glutamate (Glu-LI), aspartate (Asp-LI), glutamine (Gln-LI), gamma-amino-butyrate (GABA-LI) and taurine (Tau-LI) have been demonstrated by specific antibodies after fixation of the slices in glutaraldehyde. Prolonged depolarisation depleted Glu-LI, Asp-LI and Gln-LI from nerve-ending-like structures. GABA-LI was less affected and Tau-LI not affected at all. The depletion of immunoreactivities could be prevented by metabolic precursors of transmitter amino acids, notably glutamine. This effect of glutamine was abolished by inhibiting glutaminase with diazooxonorleucine. Glu-LI, Asp-LI, GABA-LI and Gln-LI accumulated in astroglial cells during conditions of prolonged depolarization-induced release. The accumulation of GABA-LI in glia was strongly increased by inhibition of aminotransferases by aminooxyacetic acid. The described changes in Glu-LI were prevented by low Ca2+/high Mg2+, and promoted when the glial enzyme glutamine synthetase was inhibited by methionine sulfoximine. D-Aspartate, a metabolically inert competitive inhibitor/substrate for high affinity uptake of glutamate, inhibited the accumulation of Glu-LI in glia. The results confirm the biochemically derived theories on metabolic compartmentation in nervous tissue, and add knowledge on the dynamics of the cellular distribution of amino acids. They also indicate the possibilities offered by the present approach for studying metabolism and pharmacology at the cellular level.","PeriodicalId":18313,"journal":{"name":"Medical biology","volume":"64 2-3","pages":"127-32"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14012784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluation of the immunocytochemical method for amino acids. 氨基酸免疫细胞化学方法的评价。

Medical biology Pub Date : 1986-01-01

O P Ottersen, J Storm-Mathisen, S Madsen, S Skumlien, J Strømhaug

{"title":"Evaluation of the immunocytochemical method for amino acids.","authors":"O P Ottersen, J Storm-Mathisen, S Madsen, S Skumlien, J Strømhaug","doi":"","DOIUrl":"","url":null,"abstract":"Free amino acids can be coupled to proteins by glutaraldehyde. Rabbits immunised with a bovine serum albumin-glutaraldehyde-amino acid conjugate form antibodies that recognise similar conjugates with brain proteins in glutaraldehyde-fixed tissue. Antisera raised against conjugated GABA (gamma-aminobutyrate), glutamate, aspartate, taurine, glutamine, or glycine were tested against a variety of small molecular compounds that had been fixed by glutaraldehyde to brain protein and immobilised on cellulose ester filters for processing together with the brain sections. This system permitted closely similar conditions for testing and immunocytochemistry. After removing antibodies against the carrier used for immunisation and against cross reacting amino acid conjugates the antisera showed a high specificity. The specific nature of the antisera was corroborated by solid phase adsorption to the homologous antigens and by inhibition experiments with free amino acids and amino acid-glutaraldehyde fixation complexes. After transection of the striatonigral pathway the ipsilateral substantia nigra was almost depleted of GABA-like immunoreactivity; this observation lends additional support to the selectivity of the GABA antiserum. A semiquantitative relation was established between the concentration of amino acid before fixation in a model system and the subsequent intensity of immunostaining. Similar model experiments suggested that the conjugation of an amino acid to brain protein with glutaraldehyde, and the immunoreactivity of the conjugates, may be significantly inhibited in the presence of high concentrations of other amino compounds.","PeriodicalId":18313,"journal":{"name":"Medical biology","volume":"64 2-3","pages":"147-58"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14012785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Diethyldithiocarbamate, but not disulfiram, inhibits alloxan-induced dye accumulation of isolated mouse islet beta-cells. 二乙基二硫代氨基甲酸酯，而非双硫仑，抑制离体小鼠胰岛β细胞四氧嘧啶诱导的染料积累。

Medical biology Pub Date : 1986-01-01

L Norlund, K Grankvist, H A Hansson, R Norlund

引用次数: 0