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51.
PURPOSE: The clinical effect of high-dose-rate (HDR) interstitial brachytherapy combined with tumor resection was investigated in this retrospective study on patients with recurrent oral and oropharyngeal squamous cell carcinoma. PATIENTS AND METHODS: Oral and oropharyngeal squamous cell carcinoma in 38 patients were treated over a period of 7 years (1988-1994) by HDR interstitial brachytherapy using Gammamed 12i equipment. Pretreatment of patients in terms of irradiation and surgery differed (33 irradiated with a total dose between 60.0 and 75.6 Gy, including 8 patients with additional surgery; 1 patient with surgery alone, and 4 patients without any pretreatment). Indications for interstitial brachytherapy differed according to individual responses to treatment and medical histories. RESULTS: Interstitial brachytherapy was successful in the majority of patients, i.e. complete remission: 12, partial remission: 19, no change: 2, progression: 5. Local control and overall survival including patients with surgical treatment was 59% and 81% at 6 months and 47% and 49% after 12 months, respectively. CONCLUSION: Interstitial HDR brachytherapy with Iridium 192 is recommended in patients with local recurrences or second primary carcinomas after previous external radiotherapy in the head and neck region. Combination of interstitial brachytherapy and surgery is preferable for these patients.  相似文献   
52.
PURPOSE: To evaluate factors that lead to the diagnosis of hemochromatosis probands in a community hospital, including education of physicians about hemochromatosis and iron overload, specialty of physicians, diagnostic indicators of hemochromatosis, and clinical manifestations of hemochromatosis probands. PATIENTS AND METHODS: We conducted a hemochromatosis education program for health care personnel associated with a community hospital and the public during 1990 to 1994. Data on physicians who diagnosed probands, diagnostic indicators of hemochromatosis, and manifestations of hemochromatosis and associated illnesses were tabulated. Iron grades of all hospital liver biopsy specimens obtained from Caucasian subjects during 1990 to 1994 were also analyzed. RESULTS: We identified 162 hemochromatosis probands; 66.7% were diagnosed by physicians who participated in our education program. Primary care and internal medicine subspecialty physicians diagnosed 66.7% and 29.6% of probands, respectively, based on elevated serum iron parameters and hepatic enzyme concentrations (51.9% and 36.4% of probands, respectively). Iron overload occurred in 90.7%, and was associated with clinical manifestations in most. Of 844 hospital liver biopsy specimens from Caucasians, 8.5% had increased iron grades; 4.6% represented hemochromatosis. CONCLUSIONS: Physicians with current education readily diagnose hemochromatosis probands during routine health care delivery, but most probands identified in this manner have iron overload. Our results suggest that community physicians and hospitals could contribute substantially to hemochromatosis screening programs, permitting detection of more homozygotes before the development of iron overload.  相似文献   
53.
Two new oligosaccharides were prepared from heparin by its partial depolymerization using heparin lyase I (EC 4.2.2.7) in an attempt to prepare oligosaccharides having intact antithrombin III binding sites. The oligosaccharides were purified by chromatography on the basis of both size and charge and demonstrated a high level of purity by capillary electrophoresis. One- and two-dimensional 1H NMR spectroscopy at 500 MHz revealed the structure of each oligosaccharide. The octasaccharide and decasaccharide are DeltaUAp2S(1-->4)-alpha-DGlcNpS6S(1-->4)-alpha-L-IdoAp (1-->4)-alpha-D -GlcNpAc6S(1-->4)-betaD-GlcAp(1-->4)-alpha-D-GlcNpS 3S6S(1-->4)-alpha- L-IdoAp2S(1-->4)alpha-D-GlcNpS6S (where DeltaUAp is 4-deoxy-alpha-L-threo-hex-enopyranosyluronic acid, GlcNp is 2-amino-2-deoxy-glucopyranose, GlcAp is glucopyranosyluronic acid, S is sulfate and Ac is acetate) and DeltaUAp2S(1-->4)-alpha-D-GlcNpS6S(1-->4)-alpha-L-IdoAp++ +(1-->4)-alpha- D-GlcNpAc6S (1-->4)-beta-D-GlcAp(1-->4)-alpha-D-GlcNpS3S6S(1-->4)-alpha- L-IdoAp2S (1-->4)-alpha-D-GlcNpS6S(1-->4)-alpha-L-IdoAp2S(1-->4)-alpha -D-GlcNpS 6S, respectively. A hexasaccharide containing a similar structural motif to that found in the antithrombin III binding site and having greatly reduced anticoagulant activity was also isolated. The structure of the hexasaccharide is DeltaUAp2S(1-->4)-alpha-D-GlcNpAc6S(1-->4)-beta-D-GlcAp++ +(1-->4)-alpha- D-GlcNpS3S6S(1-->4)-alpha-L-IdoAp(1-->4)-alpha-D-GlcNpS6S . The octasaccharide and decasaccharide correspond to the predominant structural motif found in porcine intestinal mucosal heparin. Sufficient quantities of the decasaccharide were obtained to examine its interaction with antithrombin III using microtitration calorimetry. This decasaccharide bound to antithrombin III with similar avidity as heparin and showed comparable anticoagulant activity, as determined using an antithrombin III dependent anti-factor Xa assay. Interestingly, while both decasaccharide and heparin bound to antithrombin with nanomolar affinity, very little heat of binding was observed.  相似文献   
54.
Babesia odocoilei continuously cultured in white-tailed deer (Odocoileus virginianus) erythrocytes was examined by transmission and scanning electron microscopy. Merozoites, trophozoites, intermediate-stage forms, and dividing forms were observed. Merozoites possessed a single nucleus, inner membrane complex, rhoptries, free ribosomes, rough endoplasmic reticulum, and single membrane-bound vesicles. Trophozoites lacked an inner membrane complex and rhoptries. Intermediate stages were characterized by distinct segments of inner membrane complex. Dividing forms ranged from cells with an elongated nucleus to mature daughter cells joined by a ringlike structure. Babesia odocoilei was characterized by its close proximity to the erythrocyte membrane, membranous structures resembling feeding organelles, and reproduction via a method resembling budding sensu stricto.  相似文献   
55.
Recent studies have found lower red cell plasma membrane contents and composition of the long chain polyunsaturated essential fatty acid derivatives, particularly arachidonic acid and docosahexaenoic acid, in a subgroup of chronic schizophrenic patients. These fatty acids are particularly enriched in the brain. Red blood cell levels of fatty acids are influenced by diet, medications, and other factors. Cell plasma membrane compositions of arachidonic and docosahexaenoic acids were therefore examined in cultured skin fibroblasts from 12 schizophrenic patients, 8 of whom were drug-naive and in a first episode of psychosis, 6 bipolar patients, and 8 normal control subjects. Docosahexaenoic acid as well as total n-3 essential fatty acid contents were significantly lower in cell lines from schizophrenic patients than in cell lines from bipolar patients and normal subjects, with no difference between the latter two groups. Arachidonic acid levels did not differ across the groups. The essential fatty acid profile observed is consistent with deficient delta-4 desaturase activity in schizophrenic patients.  相似文献   
56.
Interferon-gamma (IFN-gamma) has the most potent immunomodulatory activity of all the interferons. This phase II-B study was performed to define time- and dose-dependent immunomodulatory effects mediated by IFN-gamma in a subset of patients with melanoma treated in the dose-seeking therapeutic trial conducted by the Eastern Cooperative Oncology Group E4687 (13). The effects of IFN-gamma (Genentech, San Francisco, CA) were evaluated for phenotype and function of peripheral blood lymphocytes obtained twice prestudy, and on days 2, 9, and 29 of IFN-gamma therapy for 50 patients. Early significant increases in CD4/CD8 ratio (p = 0.001) were noted, largely due to a rise in CD4+ and fall in CD8+ T-cell populations sustained through day 29 at only the lowest dosage. Increased natural killer cell (NK) activity (p = 0.001 on day 9; p = 0.01 on day 29) was accompanied by durable increases in circulating activated NK cells (CD56+DR+% p = 0.001, day 9; p = 0.001, day 29). After initial depression of CD56+ and CD16+ cells on day 2, the total percent of CD56+ and CD16+ cells increased significantly by day 29. Increases in NK cell activity were maximal at doses > or =0.1 mg. Monocyte CD14+ expression of DQ+ rose early (p = 0.011 and 0.001 on days 2 and 9), accompanied by elevation in CD14+DR+ cells that was less significant. Immunomodulatory effects of IFN-gamma reported in this trial have major implications for interpretation of past and current clinical trials, and the design of future trials. This is the first trial in which IFN-gamma has been shown to have significant effects on the T-cell compartment of the immune system.  相似文献   
57.
Coccidioides immitis, the primary pathogenic fungus that causes coccidioidomycosis, is most commonly found in the deserts of the southwestern United States and Central and South America. During the early 1990s, the incidence of coccidioidomycosis in California increased dramatically. Even though most infections are subclinical or self-limited, the outbreak is estimated to have cost more than $66 million in direct medical expenses and time lost from work in Kern County, California, alone. In addition to the financial loss, this pathogen causes serious and life-threatening disseminated infections, especially among the immunosuppressed, including AIDS patients. This article discusses factors that may be responsible for the increased incidence of coccidioidomycosis (e.g., climatic and demographic changes and the clinical problems of coccidioidomycosis in the immunocompromised) and new approaches to therapy and prevention.  相似文献   
58.
Despite current interest in the multi-dimensionality of culture and ethnicity there are few studies that have explored the role of discrimination with ethnocultural variables. In this study social identity theory was used as a framework to test the relation between discrimination and components of ethnic identity, and attitudes towards out-groups. A school-based survey in a large south-west metropolitan area in 1994 was undertaken with students (n=3071) of African-American, European-American, Mexican-American, and Vietnamese-American descent using multiple measures of ethnicity. Hierarchical multiple regression results indicated that two components of ethnic identity played different roles in the relation between discrimination and attitudes towards others. Consistent with social identity theory, results indicated that perception of more discrimination was predicted by high ethnic exploration, and having more negative attitudes towards out-groups. However, ethnic affirmation, which is a positive sense of belonging to one's ethnic group, was only indirectly related to discrimination through attitudes toward others. In fact, contrary to social identity theory, a stronger sense of belonging to one's group was associated with more positive attitudes toward out-groups. Results have important implications for race relations.  相似文献   
59.
Flora-bearing mice with targeted disruption of T cell receptor (TCR)-alpha or -beta genes spontaneously develop intestinal inflammation with features similar to ulcerative colitis in humans. TCR-alpha-deficient mice maintained germfree or colonized with a limited number of intestinal bacteria failed to develop inflammatory bowel disease (IBD)-like lesions. Evidently, inflammation in these mice does not develop spontaneously or result from a generalized antigenic stimulation, but rather requires induction by a heretofore unidentified specific stimulus. We describe the development of IBD-like lesions in germfree TCR-alpha-deficient mice monoassociated with the protozoan Cryptosporidium parvum. Lesions were seen in distal ileum, cecum, and colon and were most severe in the cecum. A prominent leukocytic infiltrate within the lamina propria was a common characteristic of the lesions observed in the C. parvum-infected germfree TCR-alpha-deficient mice. The leukocytic infiltrate was composed of aggregates of B220+ cells, the majority of which expressed surface IgD (ie, conventional B lymphocytes). It has been proposed that antigenic stimulation by a microorganism(s) is needed to initiate intestinal inflammation in TCR-alpha-deficient mice. Our results indicate that a single microbial species, C. parvum, is capable of triggering the development of IBD-like lesions in germfree TCR-alpha-deficient mice.  相似文献   
60.
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