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1.
I Lee V E Gould J A Radosevich A Thor Y X Ma J Schlom S T Rosen 《Virchows Archiv. B, Cell pathology including molecular pathology》1987,53(3):146-152
We undertook an immunohistochemical analysis of human bronchopulmonary epithelial neoplasms and pleural mesotheliomas using a monoclonal antibody which recognizes ras oncogene products (p21ras). The monoclonal antibody, RAP-5, recognizes both unaltered and certain mutated p21ras. Formalin fixed and paraffin embedded tissue samples of 187 lung epithelial tumors and 27 pleural mesotheliomas were investigated; normal and bronchiectatic lungs were similarly studied. Normal lung and pleural tissue did not immunostain except for occasional type II pneumocytes. Reactive type II pneumocytes adjacent to carcinomas and bronchiectasis immunostained consistently. Twenty four/34 (71%) squamous carcinomas immunostained. Only 8/50 (16%) adenocarcinomas immunostained focally and weakly whereas 19/24 (79%) bronchioloalveolar carcinomas immunostained. Eleven/18 (61%) large cell carcinomas immunostained with variable intensity. Eleven/13 (85%) carcinoids, 6/7 (85%) well differentiated neuroendocrine carcinomas, and 18/21 (86%) intermediate cell neuroendocrine carcinomas immunostained while none of 20 small cell neuroendocrine carcinomas immunostained. Only a few mesotheliomas were immunostained focally. Two/14 (14%) epithelial type and 1/9 (11%) biphasic type mesotheliomas immunostained weakly; none of 4 spindle cell mesotheliomas immunostained. We conclude that while at least occasional cases of most types of pulmonary epithelial neoplasms express p21ras, the frequency and intensity of the expression are distinctly greater in certain tumor types such as squamous, bronchioloalveolar, and neuroendocrine neoplasm except for the small cell type. Contrary to these lung epithelial neoplasms, most mesotheliomas did not immunostain for p21ras. Whether the enhanced p21ras expression may point to a different mechanism of transformation or may merely reflect differentiation features remains undetermined. 相似文献
2.
Michael W. Shiflett Kristy L. Gould Tom V. Smulders Timothy J. DeVoogd 《Developmental neurobiology》2002,51(3):215-222
The hippocampal formation (HF) of food‐storing birds is larger than non‐storing species, and the size of the HF in food‐storing Black‐Capped Chickadees (Poecile atricapillus) varies seasonally. We examined whether the volume of the septum, a medial forebrain structure that shares reciprocal connections with the HF, demonstrates the same species and seasonal variation as has been shown in the HF. We compared septum volume in three parid species; non‐storing Blue Tits (Parus caeruleus) and Great Tits (Parus major), and food‐storing Black‐Capped Chickadees. We found the relative septum volume to be larger in chickadees than in the non‐storing species. We also compared septum and nucleus of the diagonal band (NDB) volume of Black‐Capped Chickadees at different times of the year. We found that the relative septum volume varies seasonally in food‐storing birds. The volume of the NDB does not vary seasonally. Due to the observed species and seasonal variation, the septum, like the hippocampal formation of food‐storing birds, may be specialized for some aspects of food‐storing and spatial memory. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 215–222, 2002 相似文献
3.
4.
Treatment of 4 adult male rhesus monkeys for 8-12 months with 100-400 micrograms of a GnRH antagonist/day by means of using osmotic minipumps led to suppressed serum concentrations of LH and testosterone followed by various degrees of recovery toward pretreatment values. The serum LH response to a challenge of native GnRH was reduced by 30-75% during antagonist treatment. The serum testosterone response to GnRH was exaggerated above the response in the pretreatment period, suggesting hypersensitivity of the testis to gonadotrophin. Antagonist administration under these conditions did not alter body weight or abolish ejaculatory response. Antagonist infusion caused a 96% decrease in sperm counts. Spermatozoa recovered during the final month of antagonist treatment showed a reduced ability to penetrate denuded hamster ova. Testicular biopsies performed at the end of antagonist treatment revealed persistent spermatogenesis. However, the cellularity of the seminiferous tubules was decreased below that of pretreatment biopsies. The results of this study suggest that the amount of testosterone needed to maintain normal spermatogenesis is greater than that needed to maintain electroejaculatory response in monkeys. 相似文献
5.
Kinetic characterization of yeast alcohol dehydrogenases. Amino acid residue 294 and substrate specificity 总被引:4,自引:0,他引:4
A J Ganzhorn D W Green A D Hershey R M Gould B V Plapp 《The Journal of biological chemistry》1987,262(8):3754-3761
A three-dimensional model of yeast alcohol dehydrogenase, based on the homologous horse liver enzyme, was used to compare the substrate binding pockets of the three isozymes (I, II, and III) from Saccharomyces cerevisiae and the enzyme from Schizosaccharomyces pombe. Isozyme I and the S. pombe enzyme have methionine at position 294 (numbered as in the liver enzyme, corresponding to 270 in yeast), whereas isozymes II and III have leucine. Otherwise the active sites of the S. cerevisiae enzymes are the same. All four wild-type enzymes were produced from the cloned genes. In addition, oligonucleotide-directed mutagenesis was used to change Met-294 in alcohol dehydrogenase I to leucine. The mechanisms for all five enzymes were predominantly ordered with ethanol (but partially random with butanol) at pH 7.3 and 30 degrees C. The wild-type alcohol dehydrogenases and the leucine mutant had similar kinetic constants, except that isozyme II had 10-20-fold smaller Michaelis and inhibition constants for ethanol. Thus, residue 294 is not responsible for this difference. Apparently, substitutions outside of the substrate binding pocket indirectly affect the interactions of the alcohol dehydrogenases with ethanol. Nevertheless, the substitution of methionine with leucine in the substrate binding site of alcohol dehydrogenase I produced a 7-10-fold increase in reactivity (V/Km) with butanol, pentanol, and hexanol. The higher activity is due to tighter binding of the longer chain alcohols and to more rapid hydrogen transfer. 相似文献
6.
Lipid metabolism in various regions of squid giant nerve fiber 总被引:3,自引:0,他引:3
The purpose of this investigation was to compare the incorporation of radioactivity from various precursors into lipids of different regions of squid giant nerve fiber systems including axoplasm, axon sheath, giant fiber lobes which contain stellate ganglion cell bodies, and the remaining ganglion including giant synapses. To identify the labeled lipids, stellate ganglia including giant fiber lobes and the remaining tissue were first incubated separately with [14C]glucose, [32P]phosphate, [14C]serine, [14C]acetate and [3H]myristate. The radioactivity from glucose, after conversion to glycerol and fatty acids, was incorporated into most lipids, including triacylglycerol, free fatty acids, cardiolipin, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, phosphatidylserine, sphingomyelin and ceramide 2-aminoethylphosphanate [corrected]. The radioactivity from serine was largely incorporated into phosphatidylserine and, to a lesser extent, into other phospholipids, mainly as the base component. The sphingoid bases of ceramide and sphingomyelin were also significantly labeled. Saturated and monounsaturated and, to a lesser extent, polyunsaturated fatty acids of these lipids were synthesized from acetate, glucose and myristate. Among the major lipids, cholesterol was not labeled by any of the radioactive compounds used. Ganglion residues incorporated the most radioactivity in total lipids from either [14C]glucose or [14C]serine, followed by giant fiber lobes and then sheath. Axoplasm incorporated the least. Among various lipids, phosphatidylethanolamine with shorter saturated fatty acids and phosphatidylglycerol contained the most radioactivity from glucose in all regions. Axoplasm was characterized by a higher proportion of glucose radioactivity in ceramide, sphingomyelin and phosphatidylglycerol. Axoplasm and sheath contained a higher proportion of serine radioactivity than did the other two regions in ceramide. Essentially no radioactivity from [14C]galactose was incorporated in any region. 相似文献
7.
M N Gould H Watanabe K Kamiya K H Clifton 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1987,51(6):1081-1090
Carcinogenesis is a multistage process consisting minimally of initiation and promotion/progression stages. Radiation and many environmental xenobiotics are potent initiating agents. We have shown that initiation of carcinogenesis in vivo by these agents is a common cellular event. In the irradiated thyroid (5 Gy) at least one in 20 cells is initiated. Initiation by both radiation and chemicals has also been shown to be a common cellular event in the mammary gland. Initiation therefore is most likely not the sole rate-limiting event in the carcinogenic process. The propensity of the initiated cell to express the malignant phenotype is modulated by many factors, including environmental chemicals and physiological and genetic factors. Scopal and abscopal physiological factors can either enhance or suppress the progression of initiated cells to a frank tumour. For example, prolactin enhances the rate of progression of radiation and chemically initiated mammary tumours while glucocorticoids suppress this progression. TSH enhances the progression of radiation-initiated thyroid tumours while a scopal factor associated with unirradiated thyroid cells suppresses progression of this tumour type. 相似文献
8.
Rhizobacteria of Cotton and Their Repression of Seedling Disease Pathogens 总被引:1,自引:0,他引:1
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During the 1983 field season, the rhizobacteria (including organisms from rhizosphere soil and the root rhizoplane) of cotton plants at one location in Mississippi were inventoried at different plant growth stages. Isolates (1,000) were identified to the genus level and characterized for repression of Pythium ultimum and Rhizoctonia solani. Cotton seedlings were initially colonized by bacteria of many different genera, and populations quickly reached 108 CFU/g of root tissue. As the season progressed, the bacterial populations declined as root mass increased and the roots became more woodlike in consistency. Fluorescent pseudomonads were the most numerous gram-negative rhizobacterial isolates of those that were randomly collected and identified, and they provided the largest number of isolates with fungal repressive activity. Several other gram-negative bacterial genera were recovered throughout the growing season, and some gram-positive bacteria were also isolated routinely, but at lower numbers. There was no correlation between the proportion of rhizobacterial isolates that possessed fungal repressive activity and the plant growth stage from which the isolates were obtained. Approximately twice as many bacterial isolates demonstrated fungal repression in the agar assay compared with the inplanta assay, and isolates were found more frequently with fungal repressive activity against P. ultimum than against R. solai. 相似文献
9.
Well differentiated and small cell neuroendocrine carcinomas of the lung. Two related but distinct clinicopathologic entities 总被引:2,自引:0,他引:2
W H Warren V A Memoli V E Gould 《Virchows Archiv. B, Cell pathology including molecular pathology》1988,55(5):299-310
Twenty-two resected pulmonary well differentiated neuroendocrine carcinomas (WDNC) were re-evaluated histologically as were 28 resected intermediate-small cell neuroendocrine carcinomas (IC-SCNC). WDNC were distinguishable from IC-SCNC by their consistently recognizable organoid architecture, and by the absence or limited extent of necrosis. Furthermore, WDNC could be subclassified into 3 subsets based upon the degrees of pleomorphism, local and vascular invasion, and stromal fibrosis, the mitotic count, and the extent of tumor necrosis. Whereas all those parameters were important in discriminating between WDNC and IC-SCNC, the quality of the organoid architecture, and the extent and pattern of necrosis emerged as the most significant. WDNC with the more aggressive histologic features (subset III) had, as a group, a distinctly worse clinical course that those displaying blander features (subsets I and II). Nevertheless, even subset III of WDNC had, as a group, a longer survival than similarly treated Stages I and II IC-SCNC. We conclude that the histologic spectrum of WDNC is broader than generally recognized. Moreover, 3 subsets of WDNC are definable based on conventional histologic criteria provided sufficient, well preserved samples are examined. Even the most aggressive subset of WDNC can be thus histologically discriminated from IC-SCNC, and, given comparable stages, has a better prognosis than the latter. 相似文献
10.
Agrobacterium tumefaciens is established as a vector for gene transfer in many dicotyledonous plants but is not accepted as a vector in monocotyledonous plants, especially in the important Gramineae. The use of Agrobacterium to transfer genes into monocot species could simplify the transformation and improvement of important crop plants. In this report we describe the use of Agrobacterium to transfer a gene into corn, the regeneration of plants, and detection of the transferred genes in the F1 progeny. Shoot apices of Zea mays L. variety Funk's G90 were cocultivated with A. tumefaciens EHA 1, which harbored the plasmid pGUS3 containing genes for kanamycin resistance (NPT II) and β-glucuronidase (GUS). Plants developed from these explants within 4 to 6 weeks. Fluorometric GUS assays of leaves and immature seeds from the plants exhibited low GUS activity. Both NOS and GUS gene fragments were amplified by polymerase chain reaction in the DNA isolated from the F1 generations of one of the original transformed plants. Southern analysis showed both GUS and NPT probes hybridized to DNA in several of the F1 progeny, demonstrating the incorporation of GUS and NPT II genes into high molecular weight DNA. These data establish successful gene transfer and sexual inheritance of the genes. 相似文献