Inuntreatedserum of three patients with multiple myeloma, concentrations of inorganicphosphate ranged from 130 to 270 mg/L as measured with a chromogenic assay based on the interaction of phosphate ion with ammonium molybdate in the presence of ferrous sulfate. There were no clinical features of hyperphosphatemia, and values for total calcium concentration in serum remained within normal limits throughout. Subsequent investigations demonstrated that this hyperphosphatemia was spurious and was caused by high concentrations of the paraprotein interfering with the chromogenic assay. Because thistype ofassay,adaptedfor automated systems, is now widely used in clinical laboratones, we call attention to this limitation to avoid confusion in clinical evaluationsof patientswithmultiplemyeloma.

A premature infant with severe enteroviral infection was treated with Maalox for gastric bleeding. Bezoars formed, which were shown to contain high concentrations of magnesium. An association between antacid administration and bezoar formation in neonates has been previously suggested but has not until now been clearly documented.

Thirty women in their third trimester of pregnancy (37-42 weeks), 40 women during and 72 h after labour and 18 non-pregnant controls were studied for changes in serum and mononuclear cell cation content, and their relationship to cervical effacement and intensity of pain as measured by plasma beta endorphin concentrations during labour. Serum magnesium fell from 0.95 +/- 0.01 (mean +/- SEM) to 0.84 +/- 0.02 mmol/litre at late pregnancy and further to 0.76 +/- 0.01 during labour (P < 0.001); serum potassium fell from 4.25 +/- 0.05 to 3.79 +/- 0.06 mmol/litre (P < 0.0001) during labour; and serum calcium fell from 2.40 +/- 0.02 to 2.28 +/- 0.01 mmol/litre at late pregnancy (P < 0.001) and further to 2.25 +/- 0.02 mmol/litre during labour (P < 0.001). Mononuclear cell magnesium content rose from 4.5 +/- 0.3 to 5.6 +/- 0.04 fmol/cell (P < 0.02); potassium content rose from 37.7 +/- 2.0 to 50.9 +/- 3.0 fmol/cell (P < 0.001); and calcium content rose from 4.4 +/- 0.4 to 7.6 +/- 1.1 fmol/cell (P < 0.105). On the other hand, mononuclear cell sodium content fell from 7.2 +/- 0.5 to 3.8 +/- 0.3 fmol/cell (P < 0.001). Plasma beta endorphin concentrations increased with increasing degrees of effacement, as did intracellular Na, whereas intracellular Mg and K showed an inverse trend. A significant correlation was found between intracellular cation and beta endorphin levels (r = -0.98, Mg; -0.99, K; 0.83, Na). These changes are probably due either to intercompartmental cation shifts or possibly to endometrial ischaemia and damage during labour.

Seventy-six patients with established atherosclerotic disease were treated daily with either 250 μg of chromium orally as chromium chloride or a placebo for a period of 7 to 16 months (mean, 11.1 months). Serum chromium increased from 2.69 ± 0.09 to 12.12 ± 0.77 nmol/L (mean ± SE, P < .005). Serum triglycerides were lower (1.68 ± 0.11 and 2.10 ± 0.14 mmol/L, respectively; P < .02) in the chromium-treated patients than in the patients who received placebo, and serum high-density lipoprotein (HDL) increased (from 0.94 ± 0.05 to 1.14 ± 0.07 mmol/L, P < .005) in the patients who received chromium. There was no change in serum cholesterol or blood glucose during the study.

Thirty-three rabbits on a cholesterol-enriched diet were randomized into 6 groups and treated with daily injections of either water, 20 micrograms of potassium chromate or 1, 5, 10 or 20 micrograms of chromium chloride, respectively, for 135 days with a 2- to 10-fold increase in serum chromium. There was a marked reduction in the percentage of aortic intimal surface covered by plaque, in aortic weight and cholesterol content in the treated animals. Rabbits treated with 20 micrograms of chromium chloride showed a better response than those treated with either 10 or 20 micrograms of potassium chromate.

Serum creatinine, blood urea nitrogen and creatine phosphokinase were measured in 32 women during the last 3 weeks of pregnancy and, in a further 39 women, during and after labor. The serum creatinine increased from 61.9±0.9 to 69.8±1.8 µmol/l (mean±SEM) (P<0.05) in the third stage of labor and returned to normal by 72 h after delivery. The muscle creatine phosphokinase increased from 54±7 to 77±9.9 units (P<0.05) during the third stage and remained high (87±13.3 units) 72 h later. We conclude that these changes are due to muscle contraction and injury during delivery.

Sixteen patients (mean age 68 years) with mild to moderate hypertension were treated with either diltiazem or hydrochlorothiazide for 6 weeks, followed by enalapril for a further 6 weeks. A second group of 40 patients (mean age 71 years) was treated with either hydrochlorothiazide or enalapril for 12 weeks; nonresponders received both drugs for 8 weeks. Treatment with hydrochlorothiazide or enalapril resulted in a lowering of systolic and diastolic blood pressures, but diastolic pressure was lower in patients treated with enalapril (89 ± 2 and 82 ± 2 mm Hg, respectively; p < 0.05). Treatment with diltiazem resulted in a decrease in diastolic pressure only. Treatment with hydrochlorothiazide resulted in a 17% decrease in serum potassium (p < 0.05), which returned to normal when enalapril was substituted. Hydrochlorothiazide also produced a 23% decrease in mononuclear cell sodium content at 4 weeks (p < 0.01), with a further 15% decrease at 12 weeks (p < 0.05). Mononuclear cell potassium and magnesium also decreased at 12 weeks by 18 and 16%, respectively (p < 0.05). All these effects were reversed when enalapril was substituted. A similar pattern of events was seen with diltiazem, which was again reversed with enalapril. Finally, there was no relation between changes in mononuclear cell sodium or other cation content and changes in blood pressure.

The effect of acute stress, with and without pain, on serum and mononuclear cell cation content was studied in 205 healthy women in their last trimester of pregnancy or during normal labour, in patients with acute medical conditions in which pain was or was not present, in acute surgical conditions, and immediately prior to elective surgery. In all subjects there was a fall in serum sodium, potassium, magnesium and calcium concentrations during stress, with an apparent shift into the intracellular space. An inverse correlation was present between the severity of pain and the fall in serum cations.

1. Two hours of exposure to heat stress, resulted in hyperthermia in rabbits (Oryctolagus cuniculus). 2. This was accompanied by a severe hypocapnia, partly compensated for by a significant decrease in bicarbonate (HCO3-) concentration. 3. The severest hyperthermia (Tb = 43.5 degrees) was followed by a sharp decreased in both PaCO2 (to 20.2 torr) and HCO3- (to 9.2 mM/l), resulting in extreme metabolic acidosis (pH = 7.290). 4. The significant increase in serum osmolality (27%) is interpreted by the cumulative effect of increased electrolyte and metabolite concentrations. 5. The elevation in blood BUN, creatinine, globulin and GOT levels point to a possible damage to muscle cells by hypothermia. 6. The stable cholesterol and alkaline phosphatase levels, suggest that liver tissue was not damaged. 7. The dramatic increase in glucose from 103.8 to 348.8 mg%, and the significant increase (from 22.0 to 39.9 mg%) in BUN, suggest a possible disability of the cells to metabolize carbohydrates, accompanied by a progressive proteolysis as an alternative process for energy production. 8. The data suggest that the emergence of muscle cell damage, severe hyperglycemia and acidosis under heat stress, precedes and amplifies the deteriorating effects of high Tb in heat stressed rabbits, which often lead to mortality.

1.1. The time course of changes in the osmolality and composition of plasma and urine in response to water restriction was studied under laboratory conditions in the green toad (Bufo viridis).2.2. On soil containing 11–13% water (ca 5 atm.), the osmolality of both fluids rises, mainly due to urea accumulation, reaching ca 1000 mOsm in 10 weeks; urine remains hyposmotic to plasma.3.3. The rate of urea accumulation and maximum value reached is related to soil water potential.4.4. The rise in plasma urea concentration is due, initially, to the retention and recycling of urine urea and later, additionally, to an increased rate of urea synthesis. The process is biphasic; a surge in the first week is followed by an interval of 7–10 days before the rate increases for the second time.5.5. Plasma urea and urine potassium increase more or less simultaneously with a decrease in muscle dry weight.6.6. Together, these suggest that a major source of additional urea-nitrogen is from catabolised skeletal muscle.

Plasma beta-endorphin (BE) levels (8.6 +/- 0.8 pmol/l) (mean +/- SE) were lower in the third trimester than in non-pregnant controls (14.8 +/- 1.1 pmol/l) (P less than 0.001), increased during labor, to 29.3 +/- 4.4 pmol/l (P less than 0.005) and decreased, 72 h after delivery, to 3.5 +/- 0.4 pmol/l (P less than 0.001). BE levels were found to correlate significantly with uterine muscle contraction (r = 0.966, P less than 0.05) and with cervical effacement (r = 0.974, P less than 0.05) during labor.

Two hundred and fifty patients admitted with acute myocardial infarction were treated with a continuous infusion of magnesium sulfate for 24 h (a total of 46 mmol of elemental magnesium). Only 1 patient had ventricular fibrillation; no patient had sustained ventricular tachycardia requiring cardioversion. Twenty-five patients had short runs of non-sustained ventricular tachycardia and did not need cardioversion. In 6 further patients, the infusion had to be discontinued because of a drop in blood pressure. The in-hospital mortality for the group was 3.4%.

We describe a rapid, single-step procedure for the isolation of human lymphocytes from whole blood, suitable for a routine clinical laboratory. Lymphocyte content of sodium, potassium, magnesium and calcium were measured simultaneously in a group of controls and found to fall within expected ranges. Expression of results per mg protein produced less inter-individual variation than per unit cell. In order to examine another, physiologically different but normal population, women during pregnancy were also studied. The cation content of lymphocytes expressed per mg protein was significantly lower than for controls due to a 44% increase in protein content per cell.

The aim of this study was to characterize the dynamic changes in uterine fluid composition and acid-base status during shell calcification in the chicken. Uterine eggs at timed intervals were manually aborted and the accompanying fluid collected and analyzed for composition of osmolytes, enzymes, and acid-base parameters. Blood samples were analyzed for comparison. No considerable change in blood gases took place in relation to residence time of the calcifying egg in the uterus. A significant acidosis occurred at latter stages. Only minor changes were revealed in plasma osmotic and biochemical composition throughout egg calcification. In contrast, major changes were revealed in uterine fluid composition and acid-base status during calcification. The most prominent phenomenon was the sharp increase in CO2 partial pressure, from 82.2 Torr at 0 h to 132.8 Torr at 10 h. As bicarbonate concentration remained almost stable, fluid pH dropped from 7.412 to 7.250 within this stage. Uterine fluid sodium and chloride concentrations and osmolality dropped significantly in the course of calcification, whereas potassium concentration significantly increased. A sharp increase in glucose, calcium, and magnesium concentrations was measured in the early stages of calcification. These findings are discussed in relation to existing models for transport mechanisms of the uterine epithelial tissue. The comprehensive picture that emerges from the present study should enable future application in establishing a self-contained culturing system in vitro for studies of embryonic development.

Sir.—Leslie et al1recently reported clinically significant differences between capillary and venous bilirubin values. We, too, have compared such paired samples2and have also found significant differences, albeit in exactly the opposite direction, ie, higher values in capillary blood as opposed to the finding of Leslie et al that capillary blood levels underestimate venous levels. As our study differed as to both patient population and methodology, we wish to add our comments. In contrast to the study by Leslie et al, our study was limited only to clinically icteric infants who did not receive phototherapy. Simultaneously drawn paired samples of capillary and venous blood were obtained in random order from 20 infants and analyzed blindly by the Astra-8 (Beckman Instrument Corp Inc, Brea, Calif) autoanalyzer. The mean bilirubin level of the total capillary group was not significantly different than the mean of the venous sample group:

Osmoregulatory and volume-regulatory responses of heat-acclimated pigeons (Columba livia) were studied during normal hydration and dehydration combined with heat exposure. Dehydrated heat-exposed pigeons (exposure to 50 degrees C following 48 h of water deprivation; 16-18% mass loss) could recover 97% of their initial body mass within 30 min of free drinking at the end of heat exposure. At the end of heat exposure, body temperature increased by 3 degrees C and hematocrit increased by 12.5%. Serum electrolyte and protein concentrations increased by 33-53% (P less than 0.001). Serum osmolality reached an outstanding mean value of 436.7 +/- 28.5 mosmol/kg (n = 11), 30.5% higher than the normal mean value. Serum glutamic-pyruvic transaminase and glutamic-oxaloacetic transaminase concentrations did not change during dehydration, suggesting no impairment in circulatory function. Blood urea nitrogen increased sixfold, indicating a total shutdown of the kidney. Relative plasma volume was maintained during dehydration at the expense of extravascular spaces and with a decreased vascular permeability as indicated by the increase in Evans blue-labeled albumin half-life (control, 104 +/- 53 min; dehydration, approaching infinity). Altogether, extracellular fluid volume and intracellular fluid volume contributed 53 and 47% of the evaporative water loss, respectively. It is concluded that plasma volume regulation may play an important role in the effective thermoregulatory responses of heat-exposed dehydrated pigeons. This regulation is achieved by preferential shifts of body water reserves among the various body water compartments coinciding with a remarkable tolerance to high osmotic pressures.

A model utilizing human umbilical cord blood was used to screen for hypoglycemia in a simulated neonatal situation. The aims of the study were to assess the effect of increasing Hct concentration on Dextrostix readings, and to determine whether plasma samples, in contrast to conventional whole blood samples, were acceptable for Dextrostix determinations in selected cases. Dextrostix readings were determined on 65 whole blood samples of varying Hct, and on plasma specimens, 48 of which were paired with whole blood samples. The results were compared with plasma true glucose values. Plasma Dextrostix readings correlated well with true glucose values throughout the entire Hct range (r = .94, slope = 1.16). Whole blood Dextrostix readings, on the other hand, were Hct-dependent and, with increasing Hct values, became falsely low. As a result, a Hct values greater than 70%, whole blood Dextrostix readings were less than 50% of the true glucose value (r = .94, slope = 0.45). Plasma Dextrostix determinations may offer an accurate means of screening for neonatal hypoglycemia in asymptomatic infants with high Hct, pending laboratory glucose results.

215 patients admitted with acute myocardial infarction were prospectively evaluated for prognostic factors. When lymphocyte potassium concentration increased by up to twofold of normal, a high lymphocyte magnesium concentration was associated with a good prognosis. However, when the increase in lymphocyte potassium concentration was greater than twofold, the presence of a high lymphocyte magnesium made no difference to mortality. Age, the female sex, anterior wall infarction, high serum enzymes, heart failure, diabetes mellitus in females and serious arrhythmias were all bad prognostic signs.