Blood pressure and excretion of sodium, potassium, calcium and magnesium in 8- and 9-year old boys from 19 European centres

We have measured systolic and diastolic blood pressure and excretions of sodium, potassium, calcium and magnesium in groups of about 50 8- and 9-year-old boys from 19 European centres using standardized methods for the measurement of blood pressure and collection of urine, and by carrying out all analyses in one laboratory. Weight, height, pulse rate and environmental temperature were also studied. Mean systolic blood pressure ranged from 91 to 105 mm Hg and diastolic blood pressure from 51 to 66 mm Hg. Mean 24-h excretion of sodium was between 91 and 146 mmol/d, that of potassium between 29 and 60 mmol/d, that of calcium between 1.5 and 2.6 mmol/d and that of magnesium between 2.7 and 4.2 mmol/d. Mean sodium excretion tended to be lower and potassium excretion tended to be higher in the boys from the north-western parts of Europe. Relations between either systolic or diastolic blood pressure and electrolyte excretions were generally weak or absent. Most remarkable is that only the association between mean diastolic blood pressure and 24-h magnesium excretion (partial regression coefficient (b +/- s.e., -5.04 +/- 2.08 mm Hg/mmol/d) was statistically significant after adjusting for differences in creatinine excretion and environmental temperature. Mean systolic blood pressure was not significantly related with any of the variables measured. The partial regression coefficient (b +/- s.e.) for diastolic blood pressure on weight was 0.186 +/- 0.062 mm Hg/kg, on height 0.165 +/- 0.056 mm Hg/cm, on pulse rate 0.364 +/- 0.100 mm Hg/beats per min and on outside temperature -0.25 +/- 0.07 mm Hg/degrees C.     

A novel 37-Kd adhesive membrane protein from cloned murine bone marrow stromal cells and cloned murine hematopoietic progenitor cells

The adhesion of hematopoietic progenitor cells to bone marrow stromal cells is critical to hematopoiesis and involves multiple effector molecules. Stromal cell molecules that participate in this interaction were sought by analyzing the detergent-soluble membrane proteins of GBI/6 stromal cells that could be adsorbed by intact FDCP-1 progenitor cells. A single-chain protein from GBI/6 cells having an apparent molecular weight of 37 Kd was selectively adsorbed by FDCP-1 cells. This protein, designated p37, could be surface-radiolabeled and thus appeared to be exposed on the cell membrane. An apparently identical 37- Kd protein was expressed by three stromal cell lines, by Swiss 3T3 fibroblastic cells, and by FDCP-1 and FDCP-2 progenitor cells. p37 was selectively adsorbed from membrane lysates by a variety of murine hematopoietic cells, including erythrocytes, but not by human erythrocytes. Binding of p37 to cells was calcium-dependent, and was not affected by inhibitors of the hematopoietic homing receptor or the cell-binding or heparin-binding functions of fibronectin. It is proposed that p37 may be a novel adhesive molecule expressed on the surface of a variety of hematopoietic cells that could participate in both homotypic and heterotypic interactions of stromal and progenitor cells.     

Body composition of rural Beninese women in different seasons assessed by skinfold thickness and bioelectrical-impedance measurements and by a deuterium oxide dilution technique.

Body composition of 24 rural Beninese women was assessed in a pre- and a postharvest season by using skinfold-thickness measurements, bioelectrical-impedance analysis (BIA), and deuterium oxide (D2O) dilution. Fat mass assessed by D2O dilution was 12.3 +/- 3.3 kg; by skinfold-thickness measurements, 13.8 +/- 3.3 kg; and by BIA, 14.1 +/- 2.9 kg. Fat mass assessed by D2O was significantly lower (P less than 0.05) than fat mass assessed by the other two methods. Body weight in the postharvest season was 0.8 +/- 1.6 kg higher (P less than 0.05) than during the preharvest season. All three methods demonstrated that there were no significant changes in fat mass but that fat-free mass increased significantly (P less than 0.05) from pre- to postharvest season.