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71.
Maloney  MD; Sauser  DD; Hanson  EC; Wood  VE; Thiel  AE 《Radiology》1988,167(1):187-190
Persistent pain and decreased range of motion are disabling complications of wrist trauma. Between 1978 and 1986, in ten patients with persistent pain following trauma, arthrography depicted changes characteristic of adhesive capsulitis. Adhesive capsulitis has been described in the shoulder, hip, and ankle, but little mention has been made of this entity in other joints. Confirmation of this diagnosis requires arthrography, since there are no characteristic findings on plain radiographs. Typical arthrographic findings include decreased capacity, small volar and styloid recesses, and adhesions preventing complete opacification of the joint. The arthrographic diagnosis allows proper institution of appropriate therapy.  相似文献   
72.
The effects of subcutaneous administration of three doses of human growth hormone-releasing factor (hGRF-44 NH2 or hGRF) at doses of 100, 300 and 600 micrograms were studied in six normal young men. GH responses obtained with 100 and 300 micrograms were negligible. In contrast, the 600 micrograms dose gave a profile of response comparable in timing and magnitude to that obtained with i.v. hGRF at maximal effect doses (20, 80, 100 micrograms). Plasma immunoreactive hGRF levels (IR-hGRF) were compared after s.c. and i.v. hGRF. Mean maximal plasma concentrations were comparable with s.c. 600 micrograms and i.v. 20 micrograms. Peaks occurred earlier with i.v. hGRF (5 min as opposed to 15 min): however, return to undetectable values was obtained between 90 and 120 min after s.c. or i.v. injections. These data suggest a great loss of the peptide between the subcutaneous space and blood, without delayed absorption. High variability in plasma IR-hGRF concentrations between the subjects after the same s.c. doses was observed.  相似文献   
73.
Metal ions are known to influence the cariogenicity of dental plaque. Inhibition of acid metabolism in plaque may be of importance in this respect. Metal ions inhibit the acidogenicity of dental plaque to a different extent and it has been suggested that an enzyme inhibition based on oxidation of thiol groups may explain this observation. The aim of the present study was to evaluate the significance of oxidation of thiol groups in the inhibition of acid production in plaque by silver, tin and zinc salts. Nine subjects with 3-d sucrose induced plaque received topical applications of the metal ions. Cysteine or gilutathione, which are known to reverse thiol oxidations, were then applied in one side of the mouth. Plaque pH measurements, in the presence of sucrose, were performed prior to and up to 2 h after treatment. The results showed that the acid production inhibited by the metal ions was reactivated by cysteine or glutathione. Iodoacetamide and ρ-chloromercuribenzoate were also shown to inhibit acid formation in dental plaque. The high affinity silver, tin and zinc have for SH groups, the observed inhibitory effect of these metals, the reactivation of the metabolism by monothiols and the fact that organic sulfhydryl reagents inhibit acid formation in plaque indicate that oxidation of thiol groups may be the mechanism by which these metals exert their effect.  相似文献   
74.
75.
In the review the modern insights on the role of expression of CD40 and CD40L and the role of their interaction on tumor cells growth are analyzed. Information about the structure and biologic properties of these molecules and their interaction is presented. The question on the role of CD40/CD40L interaction is highlighted in two aspects--the possibility of tumor growth inhibition and its stimulation. According to the mentioned aspects, immunologic mechanisms providing tumor growth inhibition (the role of dendritic cells, macrophages, monocytes, cytotoxic T-lymphocytes, natural killer cells etc.), and also the possibility of apoptotic events are discussed. Possibility of tumor growth stimulation upon the influence of CD40/CD40L interaction that could occur in some cases is analyzed as well. The data of literature about new approaches to immunotherapy of cancer based on CD40/CD40L interactionare summarized.  相似文献   
76.
Immunization of adult animals with the Ehrlich ascytic cancer cells homogenate three months prior to an experiment, did not affect either tumor transplantation or the progress of cancerogenesis induced by injection of 20-methylcholanthrene oil solution into the femoral muscle. All consequences of adult animal vaccination disappeared in 30-40 days following antigen administration. Quite different consequences were observed after immunization of the newborn mice. The same antigen (Ehrlich cancer cells homogenate) injected to newborn mice on days 1 and 3 after birth in a dose that failed to develop tolerance not only significantly increased the ascytic tumor transplantation threshold (by nearly 200 times for sarcoma 37 cells and by nearly 400 times for Ehrlich cancer cells) in adult animals but also led to almost 50% inhibition of cancerogenesis (induced by injection of 20-methylcholanthrene oil solution in the femoral muscle of mature mouse) after three and even after 12 months following immunization. The MTT-analysis did not reveal any noticeable differences in the number and activity of the cytotoxic lymphocytes in populations of splenocytes obtained from the intact mice (control) and from the adult animals which had been exposed to postnatal immunization (experiment).However, after a new vaccination such differences were found. In the populations of splenocytes obtained from control animals, the cytotoxic activity measured on day 10 after vaccination had increased 2.86-fold mainly at the expense of an increased number of effector cells. In the populations of splenocytes obtained from the experimental group of animals the activation was much greater (25.8-fold), being accomplished not only at the expense of an increased number of the effector cells, as observed in the control group, but also at the expense of their higher activity. The kinetic analysis of a mechanism of effector cells/target cells interaction has led to derive equations for estimation of the limiting rates of such interaction and of the equilibrium constants for interacting cells. Analysis of a generally accepted mechanism of the cytotoxic lymphocytes formation, with an account of the kinetic analysis data, has shown that a major reason of low antitumor resistance of animal organism is the negligible population of resting cells--the precursors of antitumor cytotoxic lymphocytes. Newborn mice vaccination does not produce any increase in the number of resting cells of the necessary type. This circumstance explains both, increase of the ascytic tumor transplantation threshold and increase of the resistance to 20-methylcholanthrene action in adulthood. Adult animal immunization does not possess such action. Analysis of the problem leads to the conclusion that the system of organism's antitumor resistance becomes effective only in those cases when, owing to antigen activation of resting cells, the concentration of cytotoxic lymphocytes rises to such an extent that the rate of tumor cell destruction becomes greater than the rate of target cells reproduction.  相似文献   
77.
78.
介入治疗激素性股骨头坏死的实验研究   总被引:2,自引:0,他引:2  
目的:探讨介入治疗激素性股骨头坏死的作用机制。方法:将24只兔子随机分为对照组、模型组、介入组。于介入前后行血管造影检查,并于治疗后8周,分别进行血液流变学、血脂及病理学观察。结果:介入组血管中断现象改善,终末小血管数目增我。全血粘度、血浆粘度,红细胞聚集指数、总胆固醇、甘油三脂,股骨头空骨陷窝率均明显低于模型组(P<0.05),软骨下区血管数目增多(P<0.01)。结论:介入、静脉注射治疗股骨头坏死,可以降低血脂,改善血液循环,通过改善股骨头血供,降低骨内压,促进坏死骨修复和新骨再生。  相似文献   
79.
80.
Meng  Q; Recio  L; Reilly  AA; Wong  BA; Bauer  M; Walker  VE 《Carcinogenesis》1998,19(6):1019-1027
1,3-Butadiene (BD) is an indirect alkylating agent that has greater cancer potency in the mouse than in the rat. The purpose of the present study was to compare the mutagenic potency of BD at the hprt locus of T- lymphocytes of exposed mice and rats and to determine whether mutations induced in this marker gene can be used as a quantitative indicator for species differences in susceptibility to cancer. To this end, experiments were conducted to define the effects of exposure duration and the time elapsed after exposures on the frequency of hprt mutations (Mf) in T-cells from female B6C3F1 mice and F344 rats of similar age (4- 5 weeks) when exposed to BD by inhalation. The accumulation of hprt mutations in T-cells from thymus was assessed in animals necropsied 2 weeks after exposure to 0 or 1250 ppm BD for 1 or 2 weeks, while the time course for the appearance of hprt mutant T-cells (i.e., the phenotypic expression and cell migration) in thymus and spleen was evaluated in animals necropsied at weekly/biweekly intervals up to 10 weeks after exposure for 2 weeks. At necropsy, T-cells were isolated from thymus and spleen and cultured in the presence of IL-2, concanavalin A, and 6-thioguanine (Walker and Skopek, Mutat. Res., 288, 151-162, 1993). BD exposures of 1 and 2 weeks led to mutagenic effects in mouse thymus, with the average Mfs being 3- and 5-fold greater than background values, respectively. In rat thymus, there was only a 1.7- fold increase in Mfs after 2 weeks of BD exposure. In the mutant expression experiment, hprt Mfs in thymus and spleen of both species increased for several weeks post-exposure and then declined. Hprt Mfs in thymus reached maximum levels at 2 weeks post-exposure in mice (Mfs = 11.3 +/- 2.4 x 10(-6)) and at 3 weeks post-exposure in rats (4.9 +/- 1.2 x 10(-6)), while hprt Mfs in spleen reached peak levels at 5 weeks post-exposure in mice (19.7 +/- 1.9 x 10(-6)) and 4 weeks post-exposure in rats (10.1 +/- 1.8 x 10(-6)). Background Mfs for mouse and rat thymus and spleen ranged from 1.6 +/- 0.3 x 10(-6) to 3.0 +/- 1.1 x 10(- 6). Statistical analyses of the hprt Mf data for spleen demonstrated that, under these exposure conditions, the mutagenic potency of BD (represented by the difference in the areas under the phenotypic expression curves of treated versus control animals) was 5-fold greater in mice than in rats. The magnitude of the species differences in mutagenic potency, observed after 2 weeks of BD exposure, resembles the species differences in metabolism more closely than the species differences in cancer potency.   相似文献   
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