A prospective study of bone loss in African-American and white women--a clinical research center study

Although bone loss occurs universally with age, the incidence of age-related osteoporotic fractures varies widely among ethnic groups. In the U.S., age-adjusted hip fracture incidence is 50% lower in African-American than in white women. Adult African-American women also have higher bone mass, but it is not known whether this difference is entirely due to higher peak bone mass or also results from slower rates of bone loss. Rates of bone loss were measured prospectively in 122 white and 121 African-American healthy, nonobese, pre- and postmenopausal women. Bone density was measured at 6-month intervals over a mean of 3-4 yr using single and dual photon absorptiometry of the forearm (cortical bone) and spine (trabecular bone). Similar rates of premenopausal bone loss were documented in both white and African-American women. However, in early menopause, bone loss was faster in the white women in the forearm (-2.4%/yr in whites vs. -1.2%/yr in African-Americans; P = 0.045), with a similar trend in the spine (-2.2%/yr in whites vs. -1.3/yr in African-Americans; P = 0.27). In women more than 5 yr postmenopause, the rates of bone loss did not differ by ethnic group. Our results indicate that the higher bone mass in African-American women is largely due to the attainment of a greater peak bone mass by early adulthood. However, slower rates of bone loss in the early postmenopausal period may also contribute to the higher bone density of older African-American women. Although bone loss occurs in both groups, there are ethnic differences in bone loss rates which indicate that data derived from white women cannot be simply extrapolated to nonwhite populations. Ethnic group-specific data on the determinants of bone homeostasis are needed.     

Treatment of venous thromboembolism

This review provides meta-analytic data of studies aiming at improved treatment of deep vein thrombosis and pulmonary embolism. The introduction of low molecular weight heparin has considerably ameliorated the initial treatment of deep vein thrombosis, and should now be regarded as the treatment of choice for most patients with deep vein thrombosis. Oral anticoagulant treatment is presently considered safe and effective for the long-term treatment of venous thromboembolism, provided that the INR is maintained at 2.0-3.0. However, the optimal duration as well as the optimal intensity of anticoagulation have still to be determined. Patients with submassive pulmonary embolism should presently be treated with adjusted dose unfractionated heparin and coumarins. Studies determining the efficacy and safety of low molecular weight heparin in this condition deserve priority. Thrombolytic therapy should be restricted to patients with massive pulmonary embolism, unless safer methods of thrombolysis have been developed. Surgical embolectomy and catheter fragmentation of emboli seem alternative options but deserve further investigations.     

Affected-sib-pair mapping of a novel susceptibility gene to insulin-dependent diabetes mellitus (IDDM8) on chromosome 6q25-q27

Affected-sib-pair analyses were performed using 104 Caucasian families to map genes that predispose to insulin-dependent diabetes mellitus (IDDM). We have obtained linkage evidence for D6S446 (maximum lod score [MLS] = 2.8) and for D6S264 (MLS = 2.0) on 6q25-q27. Together with a previously reported data set, linkage can be firmly established (MLS = 3.4 for D6S264), and the disease locus has been designated IDDM8. With analysis of independent families, we confirmed linkage evidence for the previously identified IDDM3 (15q) and DDM7 (2q). We also typed additional markers in the regions containing IDDM3, IDDM4, IDDM5, and IDDM8. Preliminary linkage evidence for a novel region on chromosome 4q (D4S1566) has been found in 47 Florida families (P < .03). We also found evidence of linkage for two regions previously identified as potential linkages in the Florida subset: D3S1303 on 3q (P < .04) and D7S486 on 7q (P < .03). We could not confirm linkage with eight other regions (D1S191, D1S412, D4S1604, D8S264, D8S556, D10S193, D13S158, and D18S64) previously identified as potential linkages.     

Effect of twist on the longitudinal field loss for an in situ superconductor

The effect of twist on the full penetration loss of an in situ superconductor is calculated for the case of a longitudinal applied magnetic field. An increase in hysteresis with increasing twist is predicted due to a large anisotropy in the critical current density. The anisotropy results from the fact that the critical current density along the length of a filament in the in situ material is determined by the filament, while along the thickness it is determined by the proximity effect in the matrix surrounding the filament. From the measurements of Braginski and Wagner the ratio of these critical current densities is calculated to be about 70, which is in order of magnitude agreement with the value previously found from transverse field measurement.     

Serial soluble interleukin 2 receptor levels in rheumatoid arthritis: differences in response to glucocorticoid treatment and chrysotherapy

OBJECTIVE: To analyze the changes in soluble interleukin 2 receptor (sIL-2R) levels following treatment of patients with rheumatoid arthritis (RA). METHODS: Serial measurements of sIL-2R levels were made over 24 weeks in 40 patients with RA, treated with intramuscular (im) gold plus 3 im injections of either 120 mg methylprednisolone acetate or placebo. RESULTS: sIL-2R levels were reduced in the glucocorticoid treated group in contrast to the gold only group, where levels initially increased. At 24 weeks, mean sIL-2R levels did not significantly differ from pretreatment levels in either group, despite improvements in clinical measures. CONCLUSIONS: In our study, sIL-2R levels do not correlate with short term clinical measures of disease activity. Their significance for longer term prognostic use remains to be determined.     

Feasibility of contour mapping epidemiological data with missing values

Data of epidemiologic interest often occur as spatial information during each of several time periods. In most cases data are available from a set of regions or localities which can be viewed as points in a plane. Although contour mapping is useful for displaying these data, the lack of data for all data points in a region may lead to erroneous interpretation. In this paper we use stimulation to investigate the impact of missing data points for contour mapping using two distinct simulated spatial-time distributions for epidemiologic variables. A model for the occurrence of malaria in localities randomly distributed in one region is chosen as the prototype for data generation.