Distribution of HIV type 1 infection in childbearing women in California.

The incidence of acquired immunodeficiency syndrome (AIDS) is increasing among California heterosexuals and children. To assess human immunodeficiency virus (HIV)-1 infection in childbearing women, we conducted a blinded serosurvey of newborns. Dried blood specimens taken from 99% of California births during the third quarter of 1988 (n = 135,808) and linked only to maternal demographic categories were tested for HIV-1 antibody by enzyme immunoassay and confirmed by Western blot. Period prevalence of HIV-1 infection was 7.4 per 10,000 childbearing women. Prevalence was highest for Black women and was also elevated for Hispanic and San Francisco Bay Area women. Findings suggest that California Hispanic women will make up an increasing proportion of new AIDS cases.     

Body composition and fat distribution influence systemic hemodynamics in the absence of obesity: the HyperGEN Study

BACKGROUND: We have shown that increased cardiac output is related to both fat-free mass and fat mass in obesity. OBJECTIVE: We studied the association of body fat distribution and body composition with flow-resistance relations in overweight. DESIGN: We studied 521 overweight, nonobese participants in the Hypertension Genetic Epidemiology Network (HyperGEN) Study-a component of the National Heart, Lung, and Blood Institute Family Blood Pressure Program, designed to assess the genetic basis of hypertension. Participants had normal ventricular function and no cardiovascular disease: 261 with central fat distribution (CFD) (waist girth >88 cm in women and >102 cm in men) and 260 with peripheral fat distribution (PFD). Fat-free mass (FFM) and fat mass (FM) were measured by bioelectric impedance. Body composition was estimated as FM/FFM. Echocardiographic stroke volume (SV) and cardiac output (CO) were measured. RESULTS: Hypertension was present in 73% of the subjects with PFD and in 78% with CFD. Overweight with CFD was associated with greater FM/FFM in both normotensive and hypertensive participants. After FFM, age, sex, and race were controlled for, SV and CO were higher in subjects overweight with CFD than in those with PFD, whereas peripheral resistance was not significantly different. Differences in CO between CFD and PFD were reduced after further adjustment for FM. After the covariates were controlled for, hypertensive subjects had higher peripheral resistance and lower arterial compliance than did normotensive participants, but cardiac output was not significantly different. CONCLUSION: CFD is associated with more severe abnormalities in body composition and with higher CO independently of FFM in overweight, nonobese subjects.     

The effect of castration, thyroidectomy and haloperidol upon the turnover rates of dopamine and norepinephrine and the kinetic properties of tyrosine hydroxylase in discrete hypothalamic nuclei of the male rat

Adult male rats were either castrated, thyroidectomized, or treated with haloperidol and the rates of turnover of dopamine (DA) and norepinephrine (NE) in the median eminence (ME), the arcuate and dorsomedial nuclei of the hypothalamus were estimated from the rate of decay of DA and NE concentrations as determined by radioenzymatic assay following blockade of catecholamine synthesis byalpha-methyl-p-tyrosine. The ME of animals similarly prepared was also examined for changes in the total activity and kinetic properties of tyrosine hydroxylase (TH). Four days following the administration of haloperidol (400 μg/kg) or 10 days after castration, there was a significant increase in the rate of turnover of DA but not NE in the ME accompanied by an increase in the V_max but notK_m for substrate or cofactor of TH. Furthermore, the administration of haloperidol to hypophysectomized rats also significantly increased the TH activity in the ME, indicating that such changes may occur independently of any changes in serum prolactin levels. Ten days after thyroidectomy, or three weeks after treatment with propylthiouracil, there was a significant increase in the turnover rate of DA in both the ME and dorsomedial nucleus but not in the arcuate nucleus. No changes in the turnover rates of NE in anu of the three areas were observed following thyroidectomy. In the ME, the increase in turnover of DA was accompanied by an increase in the total TH activity (V_max) as well as a decrease inK_m for tetrahydrobiopterin but not tyrosine. From these results 4 conclusions were drawn: (1) following haloperidol, castration, and thyroidectomy there are increases in the activity of dopaminergic terminals within the ME; (2) castration, haloperidol and thyroidectomy may influence the activity of dopaminergic terminals within the ME by different mechanisms; (3) changes in tyrosine hydroxylase and turnover of catecholamines within the ME may occur independently of changes in prolactin levels; and (4) local recurrent afferent circuits may exist in the arcuate nucleus region of the hypothalamus.     

Usefulness of the TIMI risk score in predicting both short- and long-term outcomes in the Veterans Affairs Non-Q-Wave Myocardial Infarction Strategies In-Hospital (VANQWISH) Trial

We sought to test the validity and clinical utility of the Thrombolysis In Myocardial Infarction (TIMI) risk score for patients who have non-Q-wave myocardial infarction. A post hoc analysis of the Veterans Affairs Non-Q-Wave Infarction Strategies In-Hospital (VANQWISH) Trial was performed, wherein patients were assigned a TIMI risk score from which both 30-day and 12-month outcomes (death, nonfatal myocardial infarction, or urgent revascularization) were assessed. At 30 days, the TIMI risk score showed a close match between observed and predicted probabilities of events after adjustment for overall event rates. The event rate at 30 days was 6% for a score of 0 to 2, 10% for a score of 3, 13% for a score of 4, and 14% for a score of 5 to 7 (p = 0.003 and c statistic 0.59). Discriminative ability of the score was greater in the conservative group at 30 days (p = 0.0004, c statistic 0.67). The score remained modestly predictive of events at 1 year (c statistic 0.60). Conservative strategy patients had better 30-day outcomes than the invasive strategy patients if their score was 0 to 2 (odds ratio 0.24, 95% confidence interval 0.08 to 0.76). No significant difference in outcomes between strategies was detected for a score > or =3. The TIMI risk score provides moderate incremental prognostic information in high-risk patients, during both short- and long-term follow-up.     

Limitations of current risk-adjustment models in the era of coronary stenting

Background Several risk-adjustment models have been developed to compare outcomes of conventional coronary angioplasty across physicians and institutions. Yet the accuracy of these models in contemporary interventional practice—characterized by the widespread use of stents and novel adjuvant pharmacotherapies—has not been sufficiently studied. Methods The principal published predictive models for inhospital mortality after angioplasty were validated in 11,681 patients undergoing coronary stenting and 6475 patients undergoing balloon-only procedures in the Society for Cardiac Angiography and Interventions registry from July 1996 to December 1998. We examined the 2 components of model accuracy: discrimination, as determined by the c-index; and calibration, as measured by the Hosmer-Lemeshow statistic and predicted-versus-observed probability plots. Results The discriminative properties of the models were preserved in the validation cohort and did not differ statistically from one another (c-indexes 0.85-0.89). Hosmer-Lemeshow statistics, however, showed poor fit (P < .001), with all 3 models substantially overestimating the risk of adverse outcomes. Although recalibration of the models achieved satisfactory goodness of fit, laboratory-specific ratings differed depending on the model applied. Conclusions Predictive models developed in the era of conventional angioplasty cannot be applied directly to current interventional practice. Although recalibration restores model fit, application of different recalibrated models yields inconsistent assessment of laboratory performance. Development of new, widely generalizable models is warranted, but such models will require continued reassessment as medical technology evolves and practice patterns change. (Am Heart J 2003;145:683-92.)