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Biomedical subjects

R Kumar

Publications and source records attributed to R Kumar.

At least 1,423 records · Page 79Linked to original sources

Delayed onset of maternal affection after childbirth.

Information about perceptions of labour and delivery and about immediate emotional reactions to their newborn babies was obtained from two groups of primiparous women (n = 112 and n = 41) and from 40 multiparae. About 40 per cent of primiparae and 25 per cent of multiparae recalled that their predominant emotional reaction when holding their babies for the very first time had been one of indifference. Maternal affection was more likely to be lacking after delivery if the mother had had a forewater amniotomy and had, in addition, either experienced a painful and unpleasant labour or been given more than 125 mg of pethidine. Most mothers developed affection for their babies within a week of delivery and, in all groups of subjects, no longer term adverse effects were seen, such as post-natal depression or aggressive impulses directed at the baby. Three months post-natally it was, however, found that a mother was more likely to express feelings of dislike or indifference towards her baby if she was clinically depressed at the time.

Adult↗

Orthophosphate therapy decreases urinary calcium excretion and serum 1,25-dihydroxyvitamin D concentrations in idiopathic hypercalciuria.

Orthophosphate treatment of patients with idiopathic hypercalciuria reduces the urinary excretion of calcium. To examine the role of altered vitamin D metabolism in reducing the renal excretion of calcium, we studied 11 patients with idiopathic hypercalciuria before and after 2 weeks of treatment with oral neutral orthophosphate (2 g phosphorus/day). Variables measured were urine calcium and phosphorus and seseserum calcium, phosphorus, immunoreactive parathyroid hormone, and 1,25-dihydroxyvitamin D [1,25-(OH)2D]. Oral phosphate treatment significantly decreased urine calcium excretion [mean change (delta), -123 mg/24 h], increased urine phosphorus (mean delta, serum levels of 1,25-(OH)2D (mean delta, -22 pg/ml). Pretreatment levels of 1,25-(OH)2D were high when compared with levels in age-matched controls, whether assessed as the arithmetic mean (57 vs. 33 pg/ml; P < 0.025), the logarithmically normalized (42 vs. 27 pg/ml). Phosphate treatment decreased serum levels of 1,25-(OH)2D to a mean of 35 pg/ml (logarithmically normalized mean, 22 pg/ml; median, 21 pg/ml), values not significantly different from those of normal controls. Serum calcium and phosphorus concentrations were not changed by treatment. Serum immunoreactive parathyroid hormone values increased minimally within the normal range (mean delta, +2 microleq/ml; P <0.025). We conclude that the effect of oral phosphate therapy in decreasing urinary calcium excretion may involve the reduced synthesis of 1,25-(OH)2D, independent of altered parathyroid function.

Calcitriol↗

The effect of elevated prolactin levels on plasma 1,25-dihydroxyvitamin D and intestinal absorption of calcium.

Because of evidence in experimental animals that prolactin stimulates production of 1,25-dihydroxyvitamin D, we evaluated several indices of calcium metabolism in patients who had hyperprolactinemia due to functioning pituitary adenomas and in normal age-matched controls. Plasma levels of 1,25-dihydroxyvitamin D in hyperprolactinemic patients were in the normal range (15 to 24 pg/ml versus 15 5o 75 pg/ml in controls). Intestinal absorption of calcium, plasma levels of immunoreactive parathyroid hormone, and serum values for calcium, phosphorus, and alkaline phosphatase were similar in patients and controls. We conclude that prolactin probably has no effect on plasma 1,25-dihydroxyvitamin D levels or calcium metabolism in man.

Adenoma↗

Combined effect of hypoxia and cold on the phospholipid composition of lung surfactant in rats.

The phsopholipid composition of lung tissue and lung lavage in rats exposed to acute hypoxia, chronic hypoxia, and acute and chronic hypoxia associated with cold has been estimated and compared with controls. Different fractions of phospholipids were separated by thin layer chromatography. Results showed that acute hypoxia lowered phospholipids in lung lavage but superimposition of cold lowered phospholipids both in lung tissue and lavage. In chronic hypoxia, phospholipid contents of lung tissue and lavage decreased while the addition of cold showed no further reduction in lung tissue phospholipids; on the contrary phosphatidyl choline fraction of lung lavage increased. It is concluded that the effect of hypoxia alone in lowering surfactant is related to the duration of exposure. Cold with hypoxia lowers phospholipids in the acute stage; in the chronic stage; it does not further reduce phospholipids.

Animals↗

Alveolar macrophages and pulmonary surfactant of altitude-raised rats.

Alveolar macrophages and pulmonary surfactant were estimated in rates raised at high altitude (3500 m) and compared with control rats. Macrophages were obtained by washing the lungs with isotonic saline and counted in a haemocytometer to obtain the total number present. Proportions of two types of macrophages (precursor and mature) have been evaluated. Different fractions of phospholipids in lung lavage and lung tissue were separated by thin layer chromatography and estimated colorimetically. The results showed a reduction in the number of macrophages/g of lung with a corresponding a decrease in surfactant. The percentage of immature (precursor) macrophages was lower in high-altitude-raised rates. These changes observed in alveolar macrophages and lung surfactant could be due to an altered metabolism at high altitude.

Altitude↗

Multiple pulmonary nodules in leukemia.

A patient with acute myelogenous leukemia, in clinical remission following chemotherapy, presented with three unusual pulmonary nodules. Needle biopsy showed that these were leukemic cells in the interstitium of the lung.

Adult↗

The enterohepatic physiology of 24,25-dihydroxyvitamin D3.

Products of intravenously administered [3H]24,25-dihydroxyvitamin D3 are excreted in the bile of normocalcemic, vitamin D-replete rats. Within 3 and 24 hr, 7.3% +/- 1.4 and 18.5% +/- 1.4 (mean +/- S.D.) of the administered dose appears in the bile. Three hours after the instillation of the biliary products of [3H]24,25-dihydroxyvitamin D3 into the duodena of other rats. 7.6% +/- 2.05 of the administered dose appears in newly secreted bile; at 24 hr 21.1% +/- 7.8 of the instilled dose is present in newly secreted bile. These data suggest that products of 24,25-dihydroxyvitamin D3 are excreted in bile and undergo an enterohepatic circulation. The metabolites of 24,25-dihydroxyvitamin D3 excreted in bile are much more polar than the parent sterol as assessed by silicic acid chromatography and by high-performance liquid chromatographic techniques. The products are retained on DEAE-cellulose in the presence of methanol are eluted upon the addition of acetic acid to the eluting solvent. The data support the existence of a quantitatively important enterohepatic circulation of polar metabolites of [3H]24,25-dihydroxyvitamin E3; disturbances in this metabolic pathway could help explain the pathogenesis of hepatic and intestinal osteodystrophy.

24,25-Dihydroxyvitamin D 3↗

Repair of femoral and humeral fractures in adult cattle.

Humeral or femoral fractures in 4 adult bullocks were successfully repaired with Kuntschner clover leaf nails. Animals responded favorably to surgery and physiotherapy, including massage and planned exercise. Follow-up for 1 year revealed near-normal gait and restored utility. The significance of postoperative management, especially of physiotherapy, is stressed.

Animals↗