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101.
A continuous fluorometric assay for tryptophan hydroxylase activity based on the different spectral characteristics of tryptophan and 5-hydroxytryptophan is presented. Hydroxylation of tryptophan at the 5-position results in a large increase in the fluorescence of the molecule. The assay selectively monitors the fluorescence yield of 5-hydroxytryptophan by exciting the reaction mix at 300 nm. The rate of increase of the emission signal was found to be directly proportional to the enzyme concentration. Inner filter effects due to quinonoid dihydropterin accumulation were eliminated by the inclusion of a thiol reductant. Activity measured using this assay method was found to be the same as that determined by established discontinuous HPLC assay methods. The application of the assay to routine activity measurements and to steady-state determinations with the substrates tryptophan and tetrahydropterin is described.  相似文献   
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Teniposide (VM26) has been claimed to be active with a moderate toxicity in elderly patients affected by small-cell lung cancer (SCLC). Twenty-two patients with SCLC older than 65 years received VM26 as first-line chemotherapy at a dose of 60 mg/m2 on 5 consecutive days every 3 weeks. Age distribution ranged from 67 to 80 years (median 72 years). Fourteen patients were men and eight were women. Twelve patients had limited disease (LD) and ten extensive disease (ED). One patient (LD) had a complete response, and four (3 LD, 1 ED) achieved a partial response for an overall response rate of 22.7% (95% CI 6-40%). The most frequent toxicity was myelosuppression: 20 and 15% of patients had grade 3 leukopenia and thrombocytopenia, respectively. Our results seem to suggest that VM26 by this schedule is moderately effective in elderly patients with SCLC, and it cannot be recommended as a routine treatment.  相似文献   
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BACKGROUND: Chronic myelogenous leukemia (CML) is an indolent but ultimately fatal disease. Because the natural history of CML varies and quality of life with CML may be excellent until shortly before death, deciding whether and when to pursue unrelated donor bone marrow transplantation is often difficult. OBJECTIVE: To compare early transplantation, delayed transplantation, and no transplantation for patients with chronic-phase CML on the basis of discounted, quality-adjusted life expectancy. DESIGN: A markov model comparing different strategies was constructed. This model considers patient age, quality of life, risk aversion, and the competing risks for CML progression and transplant toxicity. SETTING: Therapeutic decision at the time of diagnosis of CML. PATIENTS: The base case is a 35-year-old patient with intermediate-prognosis CML. Younger and older patients with better and worse prognoses are also evaluated. INTERVENTION: Early transplantation, delayed transplantation, and no transplantation. MEASUREMENTS: Quality-adjusted, discounted life expectancy. RESULTS: For patients with newly diagnosed CML, transplantation within the first year provides the greatest quality-adjusted expected survival, although this benefit decreases with increasing patient age. For a 35-year-old patient with intermediate-prognosis CML, transplantation within the first year results in 53 more discounted, quality-adjusted years of life expectancy than does no transplantation. This finding is robust even with varying baseline assumptions. CONCLUSIONS: These results support the use of early unrelated donor bone marrow transplantation for most patients with CML.  相似文献   
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A 68-year-old man experienced systemic pruritus since he was 63 years old, and systemic sclerosis and skin pigmentation were observed when he was 64. When he developed dyspnea the same year, he was admitted and SSc was diagnosed on the basis of the clinical and skin biopsy findings, lung fibrosis on X-P and TBLB findings. At 65, his dyspnea reappeared along with elevated blood pressure, acute renal failure and lung congestion, and he was diagnosed as having a scleroderma renal crisis (SRC) from the clinical and renal biopsy findings. Hemodialysis was started because he showed mental disturbance, and this and other acute symptoms were subsequently reduced. As he showed no recovery from his renal failure, the patient has been maintained on hemodialysis for over four years now. In the meantime, his sclerosis has improved and antinuclear antibody almost disappeared. Hemodialysis appears to be the most likely reason for his improvement, although spontaneous remission, D-penicillamine and angiotensin converting enzyme (ACE) inhibitor therapy may also have contributed, considering the short period and the small amount of drugs given until improvement.  相似文献   
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