Collection and transfusion of blood and blood components in the United States, 1992

BACKGROUND: Studies were conducted to measure the state of the United States' national blood resource in 1992 and changes therein from 1989. STUDY DESIGN AND METHODS: With data supplied by the American Red Cross and the American Association of Blood Banks, as well as data from a stratified random-sample survey of 3350 non-American Association of Blood Banks hospitals, statistical methods were applied to estimate national blood activities in 1992. RESULTS: The total US blood supply in 1992 was 13,794,000 units, a decrease of 3.1 percent from 1989. Some 11,307,000 red cell units were transfused to 3,772,000 patients, an average of 3.0 units per transfused patient. Preoperative autologous blood deposits totaled 1,117,000 units, a 70-percent increase over 1989. Of this number, 566,000 units (50.7%) were transfused, 5,000 (4.4%) transferred to the allogeneic supply, and 546,000 (48.9%) discarded. Of 436,000 directed-donation units, 136,000 (31.2%) were transfused, 57,000 (13.1%) transferred to allogeneic supply, and 243,000 (55.7%) discarded. The total allogeneic blood supply, including imports, decreased by 7.4 percent from 1989, and allogeneic blood transfusions, including those to children, decreased by 8.6 percent. Over 8,300,000 platelet units were transfused; of these, some 3,600,000 were apheresis platelets. In addition, 2,255,000 units of plasma and 939,000 units of cryoprecipitate were transfused. CONCLUSION: While the US blood supply was adequate for transfusion needs in 1992, blood collections and red cell transfusions had decreased substantially since 1989.     

Antihypertensive efficacy of metoprolol XL/Low dose chlorthalidone (6.25 mg) combination: a randomized,comparative study in Indian patients with mild-to-moderate essential hypertension

Objective

High blood pressure is one of the most important risk factors, directly responsible for increasing the cardiovascular morbidity and mortality. The primary objective was to evaluate the efficacy of metoprolol XL/chlorthalidone against metoprolol XL/hydrochlorothiazide with respect to mean fall in systolic and diastolic blood pressure. The secondary objective was to compare the response rates and to evaluate the tolerability of study medications in patients with mild-tomoderate essential hypertension.

Methods

Total 130 eligible patients (65: metoprolol XL 25 mg/chlorthalidone 6.25 mg; 65: metoprolol XL 25 mg/HCTZ 12.5 mg) were enrolled in this randomized, comparative, multicentric, 12-weeks study. Sixty-two patients from each group completed the study. After 4-weeks of treatment, non-responders from chlorthalidone 6.25 mg combination group were shifted to metoprolol XL 50 mg/chlorthalidone 12.5 mg and non-responders from HCTZ 12.5 mg combination group were escalated to metoprolol XL 50 mg/HCTZ 12.5 mg.

Results

The study treatment groups were comparable with respect to demography and baseline disease characteristics. Both the starting therapies were comparable with respect to mean fall in SBP (p = 0.788) and DBP (p = 0.939), and response rates (p = 1.0) after 4-weeks of therapy. Also both the step-up therapies showed similar mean fall in SBP (p = 0.277) and DBP (p = 0.507) at the end of 12-weeks. However, significantly more number of patients from chlorthalidone 12.5 mg/metoprolol XL 50 mg group responded to therapy as compared to that from HCTZ 12.5 mg/metoprolol XL 50 mg group (p = 0.045). All the reported adverse events were of mild-to-moderate intensity. There were no clinically significant trends in electrolytes (Na⁺, K⁺, Cl^-)and fasting blood sugar, evident across the treatment groups.

Conclusion

Chlorthalidone in combination with metoprolol XL is as effective and well tolerated as widely used combination of metoprolol XL/HCTZ, thus providing an alternative therapeutic option.     

Restraint and eating concern in North European and East Asian women with and without eating disorders in Australia and Singapore

OBJECTIVE: To investigate eating disorder psychopathology, restraint and eating concern in young women with and without an eating disorder from two different ethnic groups in Australia and Singapore. METHOD: The relationship of Eating Disorder Examination Questionnaire Global, Restraint and Eating Concern scores to cultural orientation and sociocultural factors was analysed in 154 women with and without an eating disorder. Participants were from the following backgrounds: North European Australian, East Asian Australian, Singaporean Chinese and North European expatriates in Singapore. RESULTS: Women with eating disorders had similar psychopathology across the cultural groups. Among controls, Singaporean Chinese reported significantly greater overall eating disorder psychopathology than other cultural groups and greater restraint than North European Australians/expatriates. Eating concern was not associated with cultural group overall or acculturation to Western culture. Dissatisfaction with family functioning, socioeconomic status and education level were not significantly associated with any of the eating disorder measures. CONCLUSION: In eating disorder psychopathology, the specific symptom of eating concern may transcend cultural influences.     

Prediction of the effect of erythromycin, diltiazem, and their metabolites, alone and in combination, on CYP3A4 inhibition

Predictive models of complex drug-drug interactions between multiple inhibitors and their metabolites have not been evaluated. The purpose of this study was to evaluate an interaction model for cytochrome P450 3A4 (CYP3A4) that incorporated the simultaneous reversible and irreversible inhibition by multiple inhibitors. Erythromycin (ERY) and diltiazem (DTZ), and their major metabolites, N-desmethylerythromycin (nd-ERY) and N-desmethyldiltiazem (nd-DTZ), were chosen to evaluate the model. k(inact) (rate constant for maximal inactivation), K(I) (inhibitor concentration at 50% maximal inactivation), and K(i) (reversible inhibition constant) were estimated for ERY, DTZ, nd-ERY, and nd-DTZ, respectively, using cDNA-expressed CYP3A4 and human liver microsomes under optimal experimental conditions. To evaluate the interaction model, combinations of inhibitors and metabolites were incubated at concentrations equal to K(I), (1/2)K(I), and 2K(I) of each inhibitor for specified durations in both enzyme systems. The models were further evaluated by the incubation of combinations of inhibitors with the substrate testosterone for 10 min. CYP3A4 inhibition in the presence of drug mixtures was predicted from the inhibition parameters determined for each drug or metabolite alone. The CYP3A4 activity in the presence of multiple inhibitors was well predicted by the model incorporating additive irreversible inhibition as modified by mutual competitive inhibition (percent mean error and percent mean absolute error ranged from -0.06 to 0.04 and from 0.03 to 0.09, respectively). In conclusion, the additive model predicted the combined effect of multiple inhibitors on CYP3A inhibition in vitro. However, simultaneous reversible and irreversible inhibition effects should be taken into account in a reaction mixture of substrate and multiple inhibitors of CYP3A4.     

Irbesartan-mediated reduction of renal and cardiac damage in insulin resistant JCR : LA-cp rats

Background and purpose:

Angiotensin II receptor antagonists (ARBs), originally developed for antihypertensive properties, have pleiotropic effects including direct vascular actions. We tested the hypothesis that the ARB irbesartan would be effective against micro- and macrovascular complications of the prediabetic metabolic syndrome using the obese, insulin-resistant JCR : LA-cp rat that exhibits micro- and macrovascular disease with ischaemic myocardial lesions and renal disease.

Experimental approach:

Obese male rats were treated with irbesartan (30 mg·kg⁻¹·day⁻¹, incorporated into chow) from 12 to 25 weeks of age.

Key results:

Irbesartan treatment caused no change in food intake or body weight. Fasting glycaemic control of the JCR : LA-cp rats was marginally improved, at the expense of increased plasma insulin levels (∼50%). Fasting plasma triglycerides were marginally reduced (∼25%), while cholesterol concentrations were unchanged. Elevated concentrations of adiponectin, monocyte chemotactic protein-1 and plasminogen activator inhibitor-1 were reduced along with severity of glomerular sclerosis. Macrovascular dysfunction (aortic hypercontractile response to noradrenergic stimulus and reduced endothelium-dependent relaxation) was improved and frequency of ischaemic myocardial lesions reduced (62%).

Conclusions and implications:

Irbesartan reduces markers of inflammation and prothombotic status, improves macrovascular function and reduces glomerular sclerosis and myocardial lesions in a model of the metabolic syndrome. Unlike pharmaceutical agents targeted on metabolic dysfunction, irbesartan reduced end-stage disease without major reduction of plasma lipids or insulin. The protective effects appear to be secondary to unknown intracellular mechanisms, probably involving signal transduction pathways. Understanding these would offer novel pharmaceutical approaches to protection against cardiovascular disease.     

Effective strategies for suicide prevention in New Zealand: a review of the evidence

A national suicide prevention strategy for New Zealand was developed in 2006. There is relatively little strong evidence for the efficacy of many existing suicide prevention initiatives, and this area has frequently been captured by strong claims about the effectiveness of programmes that have not been adequately evaluated. This paper provides a conceptual framework for classifying suicide prevention initiatives, reviews evidence for their effectiveness, and makes recommendations for initiatives to be undertaken as part of suicide prevention activities in New Zealand. The available evidence thus far suggests that the most promising interventions likely to be effective in reducing suicidal behaviours are medical practitioner and gatekeeper education, and restriction of access to lethal means of suicide. This evidence also suggests a clear agenda for research, which includes evaluating interventions and prevention programmes, developing model and demonstration projects, identifying meaningful outcome measures, and refining and identifying the critical elements of effective programmes.     

Collection and transfusion of blood in the United States, 1982-1988

Widespread concern about the safety of the national blood supply, particularly with respect to the human immunodeficiency virus (HIV), has reportedly affected the use of blood products to support patients. To examine these changes, we conducted national surveys of blood collection and transfusion in the United States in 1982, 1984, 1986, and 1987 and made a limited survey of these activities in 1988. Transfusions of whole blood and red cells reached a peak of 12.2 million units in 1986, then declined to 11.6 million units in 1987 and continued to decline in 1988. Transfusions of plasma declined from a peak of 2.3 million units in 1984 to 2.1 million units in 1987. Growth in the use of platelet transfusions (6.4 million units in 1987) also slowed; however, the proportion of platelets transfused as platelets from single donors grew from 11 percent in 1980 to 25 percent in 1987. Donations of autologous blood increased sharply, from less than 30,000 units in 1982 to 397,000 units in 1987, equivalent to 3 percent of the homologous-blood collections. The growth in collections of homologous blood slowed after 1982. The supply of homologous blood reached a peak of 13.4 million units in 1986 and did not grow between 1986 and 1988. These trends in red-cell, plasma, and platelet transfusions appear to have continued through 1988. We conclude that the unprecedented decline in transfusions of whole blood and red cells, coupled with the continued importation of packed red cells from Western Europe and the offsetting effect of autologous predeposits, forestalled serious shortages of blood that could have resulted from the decline in collections of homologous blood. We attribute these changes in blood collection and blood transfusion to the effects of the epidemic of HIV infection.