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51.
Intimal hyperplasia is induced by therapeutic vascular interventions and often results in clinically important narrowing of the vascular lumen. Examination of the role of TGF-beta 1 in a rat carotid artery injury model confirmed the presence of a previously reported increase in TGF-beta 1 mRNA in the media of injured arteries. Administration of neutralizing anti- TGF-beta 1 antibodies significantly (P < 0.05) reduced the size of the intimal lesions that developed after carotid balloon injury. A control antibody had no effect. The intimal/medial area ratio was also reduced in the anti-TGF-beta 1 group relative to controls (P < 0.01). Immunohistochemical staining showed that two TGF-beta 1-induced extracellular matrix components, EDA + fibronectin and versican, were greatly increased in the untreated neointimal lesions, but were almost completely absent from the lesions of the anti-TGF-beta 1-treated animals. We conclude that TGF-beta 1 is causally involved in the development of intimal hyperplasia, and that anti-TGF-beta 1 agents may be useful in achieving at least partial control of this condition. 相似文献
52.
53.
Hyperglycemia before ischemia worsens cerebral outcome. The aim of this study was to determine the cerebral effects of giving glucose with or without insulin after asphyxial cardiac arrest. Rats underwent 8 min of asphyxial cardiac arrest. After arrest, Group 1 received NaCl; Group 2, insulin; Group 3, glucose; and Group 4, glucose plus insulin, all intravenously. Neurological deficit (ND) scores were 14+/-10%, 22+/-12%, 12+/-10% and 2+/-2% in Groups 1-4, respectively, 72 h after reperfusion. Overall histological damage (HD) scores were 4, 2, 3 and 1, respectively. Group 4 fared significantly better than group 1 on both scores. Glucose after asphyxial cardiac arrest in rats produces no increased brain damage while glucose plus insulin improves cerebral outcome. 相似文献
54.
GP Xue JS Johnson DJ Smyth LM Dierens X Wang GD Simpson KS Gobius JH Aylward 《Canadian Metallurgical Quarterly》1996,45(1-2):120-126
Temperature-regulated expression of recombinant proteins in the tac promoter (Ptac) system was investigated. Expression levels of fungal xylanase and cellulase from N. patriciarum in E. coli strains containing the natural lacI gene under the control of the Ptac markedly increased with increasing cultivation temperature in the absence of a chemical inducer. The specific activities (units per milligram protein of crude enzyme) of the fungal xylanase and cellulase produced from recombinant E. coli strain pop2136 grown at 42 degrees C were about 4.5 times higher than those of the cells grown at 23 degrees C and were even slightly higher when compared with cells grown in the presence of the inducer isopropyl beta-D-thiogalactopyranoside. The xylanase expression level in the temperature-regulated Ptac system was about 35% of total cellular protein. However, this system can not be applied to E. coli strains containing lacIq, which confers over production of the lac repressor, for high-level expression of recombinant proteins. In comparison with the lambda PL system, the Ptac-based xylanase plasmid in E. coli pop2136 gave a considerably higher specific activity of the xylanase than did the best lambda PL-based construct using the same thermal induction procedure. The high-level expression of the xylanase using the temperature-regulated Ptac system was also obtained in 10-litre fermentation studies using a fed-batch process. These results unambiguously demonstrated that the temperature-modulated Ptac system can be used for overproduction of some non-toxic recombinant proteins. 相似文献
55.
56.
The objective of this study was to address the question of whether or not psychosocial screening should be focused on "high-risk" populations. A cross-sectional survey of mothers of young children was conducted in various clinics: 758 in teaching clinics, 444 in private practices, and 202 at a military clinic. The self-administered questionnaire covered demographic factors, problems in mothers family of origin, maternal depression, and substance abuse. Mothers in the teaching clinics were younger and had less education and lower incomes than mothers in private practices, with intermediate levels in the military clinic. However, a substantial proportion of mothers seen in all sites reported psychosocial problems. Approximately 20% of mothers in all sites reported a family history of alcoholism. Positive screens for maternal depression ranged from about 15% to 35%. Binge drinking was reported by 10% to 20% at different sites. Psychosocial problems were common even among families seen in "low-risk" settings. Focusing screening only on high-risk clinics would miss many families with psychosocial problems. 相似文献
57.
Medico-demographic processes and socio-hygienic characteristics of the population of a large city, both at an individual and familial levels, as well as territorial characteristics of residence, should be taken into consideration when developing measures for medicosocial care of the population. Analysis of the attitude of 380 city families to the activities, personality, and professional skills of local therapists and pediatricians and to the idea of primary health care rendered by a physician of a general profile demonstrated an increased activity of the families in the "physician-patient" system and confirmed the necessity of improving medicosocial care of a city family, expansion of prophylactic work with the population with due consideration for factors which have an impact on population health. 相似文献
58.
Molecular computation of solutions to combinatorial problems 总被引:9,自引:0,他引:9
LM Adleman 《Canadian Metallurgical Quarterly》1994,266(5187):1021-1024
The tools of molecular biology were used to solve an instance of the directed Hamiltonian path problem. A small graph was encoded in molecules of DNA, and the "operations" of the computation were performed with standard protocols and enzymes. This experiment demonstrates the feasibility of carrying out computations at the molecular level. 相似文献
59.
LM Williams 《Canadian Metallurgical Quarterly》1995,8(4):649-673
This study provides evidence that some adults who claim to have recovered memories of sexual abuse recall actual events that occurred in childhood. One hundred twenty-nine women with documented histories of sexual victimization in childhood were interviewed and asked about abuse history. Seventeen years following the initial report of the abuse, 80 of the women recalled the victimization. One in 10 women (16% of those who recalled the abuse) reported that at some time in the past they had forgotten about the abuse. Those with a prior period of forgetting--the women with "recovered memories"--were younger at the time of abuse and were less likely to have received support from their mothers than the women who reported that they had always remembered their victimization. The women who had recovered memories and those who had always remembered had the same number of discrepancies when their accounts of the abuse were compared to the reports from the early 1970s. 相似文献
60.
JR McFarlane LM Foulds A Pisciotta DM Robertson DM de Kretser 《Canadian Metallurgical Quarterly》1996,134(4):481-489
BACKGROUND: The aim of this morphological investigation was to obtain more information about the structural and cellular mechanisms of interalveolar pore formation in postnatal lung development. Assuming that alveolar pore formation is related to the general thinning of interalveolar walls observed in the postnatal period, we have focused our attention on the topographical relationship between epithelial cells and connective tissue in the septum. Thereby we tried to formulate a uniform concept of pore formation. METHODS: After fixation with glutaraldehyde and osmiumtetroxide, tissue blocks of rat lungs aged 44 days were embedded in Epon. Serial sections were obtained in order to analyse precisely pores and supposed sites of pore formation (type II cells and thin spots in transsections of interalveolar walls). RESULTS: We made the following observations: there are pores with or without type II cells in the neighbourhood, and "pre-pores" with either fully transseptal granular pneumocytes, or thin spots in the interalveolar wall consisting of one or two layers of type I cell epithelium or of type II and type I cells without intervening connective tissue. CONCLUSIONS: From these findings we deduce that there is a general principle of interalveolar pore formation which consists in the formation of transseptal interepithelial cell contacts (i.e., between cells of type II and type I or type I and type I), promoted by the thinning of interalveolar walls in the stage of microvascular maturation. Within the zone of contact the cells thin out and give way to form an interalveolar opening. 相似文献