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71.
BACKGROUND: Equilibration of hemoglobin concentration after transfusion has been estimated to take about 24 hours, but some studies have shown that earlier measurements reflect steady-state values in persons who have not bled recently. This study was aimed at assessing the changes over time in hemoglobin concentration after transfusion in acutely anemic patients because of recent bleeding. STUDY DESIGN AND METHODS: Thirty-two normovolemic patients recovering from an acute bleeding episode who were no longer thought to be bleeding and who received a 2- unit red cell transfusion were studied. At baseline and 15, 30, 60, and 120 minutes and 24 hours after transfusion, hemoglobin concentration and hematocrit values were measured. RESULTS: The administration of 2 units of packed red cells elicited a 24-hour increase of 22.4 +/− 6.8 g per L in hemoglobin concentration. Hemoglobin values were not different at any of the defined posttransfusion times. Hematocrit levels experienced similar changes over time. Agreement between 15-minute and 24-hour values was excellent, as only 6 percent of patients exhibited a clinically significant difference (> 6 g/L) between the hemoglobin measurements. CONCLUSION: Hemoglobin and hematocrit values rapidly equilibrate after transfusion in normovolemic patients who are recovering from an acute bleeding episode. This fact would allow a rapid assessment of the effects of transfusion and of the recurrence of bleeding in patients remaining at risk.  相似文献   
72.
OBJECTIVES. The purposes of the study were to assess the potential impact of the North American Free Trade Agreement (NAFTA) on medical care in Mexico and to identify internal measures Mexico could take to increase the benefits and minimize the risks of free trade. METHODS. The dual nature of the health sector is examined; the Mexican, Canadian, and US health care systems are compared; and modes and consequences of international exchange of health services are analyzed. RESULTS. Four issues require immediate attention: accreditation of health care facilities, licensing and certification of professionals, technology assessment, and financial equity. CONCLUSIONS. NAFTA offers opportunities for positive developments in Mexico, provided risks can be anticipated and preventive measures can be taken to avoid negative impacts on the health system. Medical services, like other elements of the Mexican economy, must be modernized to respond to the demands of global competition. The Mexican National Academy of Medicine has recommended to the Mexican government (1) internal strengthening of the Mexican health care system to improve its ability to respond to the new conditions created by NAFTA and (2) a gradual process to facilitate equitable and mutually beneficial interactions among the three countries.  相似文献   
73.
OBJECTIVE: This study was carried out to compare the efficacy of lithium carbonate with that of valproate in acute mania and to determine whether pretreatment clinical characteristics, such as the presence of a mixed affective state, might predict a differential response to the two drugs. METHOD: Twenty-seven patients meeting DSM-III-R criteria for acute manic episodes underwent a 3-week, randomized, double-blind, parallel-groups trial of treatment with lithium carbonate or valproate. Symptom severity was measured by using the Schedule for Affective Disorders and Schizophrenia, change version (SADS-C), the Global Assessment Scale (GAS), and the Brief Psychiatric Rating Scale (BPRS). Drug effects were compared by using repeated measures analysis of variance (ANOVA). RESULTS: At the end of the study, nine of 14 patients treated with valproate and 12 of 13 patients treated with lithium had responded favorably, as measured by changes in the SADS-C mania, BPRS, and GAS scores. Elevated pretreatment SADS-C depression scores were associated with good response to valproate. ANOVA revealed a significant interaction between drug and mixed affective state with respect to treatment response. CONCLUSIONS: Lithium and valproate were both effective in improving manic symptoms, and lithium was slightly more efficacious overall. Unlike the case with lithium, favorable response to valproate was associated with high pretreatment depression scores. Therefore, treatment with valproate alone may be particularly effective in manic patients with mixed affective states.  相似文献   
74.
R J Blendon  L H Aiken  H E Freeman  C R Corey 《JAMA》1989,261(2):278-281
A 1986 national survey of use of health services shows a significant deficit in access to health care among black compared with white Americans. This gap was experienced by all income levels of black Americans. In addition, the study points to significant underuse by blacks of needed medical care. Moreover, blacks compared with whites are less likely to be satisfied with the qualitative ways their physicians treat them when they are ill, more dissatisfied with the care they receive when hospitalized, and more likely to believe that the duration of their hospitalizations is too short.  相似文献   
75.
The two major applications of whole post-implantation rat embryo culture (WEC) are as a test for teratogenicity in safety evaluation studies and as a tool in the investigation of mechanisms of teratogenesis. As a test system, WEC possesses many of the characteristics necessary for an in vitro screen. However, its use on a large scale is disqualified for reasons of cost and the demand for technical expertise to perform cultures and interpret findings, compared with other in vitro teratogenicity screens, although its use might be preferred when only a few compounds require testing. The major value of WEC lies in its use for studying mechanisms of teratogenesis. The opportunity to study the embryo in isolation and the versatility afforded by the technique offer considerable advantages in this context.  相似文献   
76.
BACKGROUND: Cyclosporin has been shown to facilitate renal vasoconstriction and to have an antinatriuretic effect. The existence of an interference of cyclosporin with the vasodilating properties of endothelium mediated by nitric oxide production could mediate these effects. On the other hand, the infusion of the nitric oxide precursor L-arginine has been shown to induce renal vasodilatation and to facilitate natriuresis in normal volunteers. We have investigated the renal effects of the administration of an infusion of L-arginine in renal transplant patients chronically treated with cyclosporin. To facilitate the analysis of the data the effects of the administration of a similar dose of cyclosporin on renal function during the infusion of a vehicle were also investigated during the administration of a vehicle of L-arginine. DESIGN: Ten male renal transplant patients, chronically treated with cyclosporin and with a stable renal function were studied during 2 consecutive days after the administration of the usual morning dose of cyclosporin. The first day they received an intravenous infusion of vehicle and the second the infusion of graded doses of L-arginine (50, 100, 150 mg/kg/h) during 3 consecutive h. RESULTS: The first day, after cyclosporin administration a significant fall (P < 0.01) was observed in natriuresis and kaliuresis in the absence of changes in renal plasma flow and glomerular filtration rate. After the administration of L-arginine significant (P < 0.01) increases of renal plasma flow, glomerular filtration rate, and natriuresis were seen. The increase in blood levels of cyclosporin after its administration did not differ between days 1 and 2. CONCLUSION: These results indicate that L-arginine facilitates renal vasodilatation and natriuresis in renal transplant patients. Furthermore, the observed increase in sodium excretion could indicate that L-arginine counteracts the antinatriuretic effect of cyclosporin.   相似文献   
77.
78.
OBJECTIVE: The American Psychiatric Association's DSM-IV Work Group on Late Luteal Phase Dysphoric Disorder (LLPDD) reanalyzed existing data from prospective, daily symptom ratings to evaluate the DSM-III-R criteria for LLPDD. The objectives were to 1) evaluate the individual symptoms presently required for the diagnosis and other symptoms, 2) determine the proportion of treatment-seeking women who meet the LLPDD criteria, and 3) explore the association between LLPDD and other mental disorders. METHOD: Data from over 1,000 women seeking evaluation for premenstrual complaints at five U.S. sites were examined. The data from 670 of these women were sufficiently complete to warrant evaluation by four different methods of assessing symptom change. RESULTS: Depending on the assessment method used, 14% to 45% of the women met the criteria for LLPDD. The current DSM-III-R symptoms were classified as positive for 7% to 54% of the women. Each of these symptoms was significantly more common among women with LLPDD regardless of the assessment method used. Five symptoms not presently included were also significantly more common. Women who had had mental disorders in the past, but not present, showed a significantly greater, but very small, relative risk of LLPDD. CONCLUSIONS: The variability in the frequency of LLPDD diagnosis according to method of assessing symptom change underscores the need for a uniform assessment method. The five additional symptoms with frequencies comparable to those of the DSM-III-R symptoms should be studied further for possible inclusion in the criteria.  相似文献   
79.
Atypical retinitis in patients with the acquired immunodeficiency syndrome   总被引:1,自引:0,他引:1  
We examined three patients with AIDS who had large, sharply demarcated areas of thinned retina consistent with inactive cytomegalovirus retinitis and who were not treated with ganciclovir. These lesions appeared identical to clinically inactive areas of cytomegalovirus retinitis after effective antiviral treatment. All patients were receiving azidothymidine or ribavirin, or both, which have activity against the human immunodeficiency virus and which may improve immune function. All patients also received oral acyclovir at doses ineffective against cytomegalovirus retinitis.  相似文献   
80.
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