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Biomedical subjects

J Levi

Publications and source records attributed to J Levi.

At least 109 records · Page 6Linked to original sources
PubMed1987

Biochemical changes associated with the osmotic fragility of young and mature erythrocytes caused by parathyroid hormone in relation to the uremic syndrome.

The effect of parathyroid hormone at concentrations found in uremic patients on erythrocytes (RBC) from newborn and adult rabbits was studied in relation to the fragility pattern in hypotonic salt solutions and the activities of Ca- and Mg-dependent ATPases. Median osmotic fragility of RBC from newborn rabbits was significantly lower than in mature rabbits. Parathyroid hormone (PTH) stimulated to a greater extent the mean osmotic fragility in RBC from newborn rabbits, than in those from adults. Similarly, the hormone stimulated to a much greater extent the Ca-ATPase but not the Mg-ATPase in RBC from the newborn rabbits, in comparison to those from adult rabbits. PTH, which is greatly elevated in the blood of patients with chronic renal failure, may be one cause of the anemia seen in these patients, and its effect, which is mediated by Ca-ATPase activity, is stronger on young RBC. There were significant morphological changes in the young RBC caused by PTH, as seen with scanning electron microscopy.

Aging↗
PubMed1987

Platelet count and thrombopoietic activity in patients with chronic renal failure.

The frequency of thrombocytopenia in patients with chronic renal failure (CRF) is controversial. This study was undertaken to investigate the platelet count in 55 patients with end-stage renal disease on maintenance hemodialysis and in 19 patients with CRF before hemodialysis had begun. In both groups platelet counts were similar and significantly reduced, 175,000 +/- 6,500 and 181,000 +/- 10,800 compared to 253,000 +/- 3,700/mm3 in the control (p less than 0.0001). 31% of hemodialysis patients had thrombocytopenia (platelet count less than 150,000/mm3). The megakaryocyte number in their bone marrow aspirate was not reduced. Primary renal disease, androgen treatment or parathyroidectomy did not affect the platelet count. Thrombopoietic activity using 75Se-selenomethionine incorporation into platelets measured in 7 thrombocytopenic patients was found to be reduced, 6.77 +/- 0.29 vs. 9.06 +/- 0.27 (X 10(-2)%: p less than 0.001). This study shows that the platelet count is reduced and mild thrombocytopenia is frequent in patients with CRF. A possible cause for the platelet count reduction is insufficient thrombopoietic activity.

Adolescent↗
PubMed1987

Effect of long-term aluminum administration on the renal structure of the rat.

Kidneys of patients on hemodialysis therapy often undergo structural changes leading to acquired cystic disease. A wide variety of chemical compounds are known to induce experimental renal cystic disease. Since aluminum intoxication has been implicated in the development of encephalopathy, osteomalacia and anemia in uremic patients, this study was designed to investigate whether aluminum administration to normal rats could induce renal morphological changes. Male Wistar rats were divided into three groups; Animals of the Low-dose aluminum (LDA) group received 0.2 mg/day of aluminum, animals of the high-dose aluminum (HDA) group received 2 mg/day of aluminum; the third group consisted of controls (C). Aluminum was injected intraperitoneally as aluminum chloride (6 days a week). 13 weeks later, the kidneys were removed and examined by light and electron microscopy. The findings on eight-microscopic examination were normal in all groups. Electron-microscopic examination was unremarkable in the C and LDA group. In HDA rats, ultrasections of the cortex and outer medulla showed changes in the proximal tubules with increased size and number of lysosomes, osmiophilic granular material inside the lysosomes, vacuolisation of organelles and mitochondrial damage of varying degree. No cystic changes were found.

Aluminum↗
PubMed1987

Effect of parathyroid hormone on the fragility and enzyme activities of red blood cells from young and mature rabbits.

The effect of parathyroid hormone on erythrocytes from newborn and adult rabbits was studied in relation to the fragility pattern in hypotonic salt solutions and the activities of Ca- and Mg-dependent ATPases. Median osmotic fragility of red blood cells from newborn rabbits was significantly higher than in red blood cells from mature rabbits. Parathyroid hormone increased the mean osmotic fragility of red blood cells from newborn and adult rabbits, but showed the greater effect on those from newborns. Similarly, the hormone stimulated to a much greater extent the Ca-ATPase, but not the Mg-ATPase in red blood cells from the newborn rabbits, in comparison with red blood cells from adult rabbits. Parathyroid hormone, which is greatly elevated in the blood of patients with chronic renal failure, may be one cause for the anaemia seen in these patients, and its effect, which is mediated by Ca-ATPase activity, is stronger on young red blood cells. Significant morphological changes in the young red blood cells, observed by scanning electron microscopy, were caused by parathyroid hormone.

Aging↗
PubMed1987

Phase I study of epirubicin given on a weekly schedule.

Epirubicin was studied in a phase I setting to find the maximum tolerated dose when given weekly for 3 of 4 weeks. Forty-one evaluable patients were treated in groups at doses increasing from 20 to 45 mg/m2. The highest dose level produced the maximum degree of myelosuppression (lowest neutrophil count, 1.9 X 10(9)/L; range, 0-3.7) recorded on Day 22. This was well-tolerated in this group of mainly pretreated patients. Nonhematologic side effects were minimal. This dose schedule allows a greater dose per unit time to be administered than other recommended schedules for epirubicin.

Adult↗
PubMed1987

Effect of verapamil on plasma parathyroid hormone.

The effects of the Ca antagonist, verapamil, on the behaviour of parathyroid hormone was studied in normal and uraemic male Wistar rats. Parathyroidectomy was by cautery. Acute uraemia was induced by bilateral nephrectomy, and moderate uraemia by s.c. injection of gentamicin (200 mg/kg). Ethylendiamine tetracetic acid (50 mg/kg X d) was injected subcutaneously. Parathyroid hormone was determined by radioimmunoassay. The degree of uraemia was determined from plasma urea levels. Renal failure resulted in a significant increase in plasma parathyroid hormone (mean +/- SEM, ng/l) (84 +/- 6, n = 10, in the control; 277 +/- 39, n = 7, in the moderate uraemics and 667 +/- 128, n = 6, in the acute uraemics). Injection of verapamil significantly increased plasma levels of parathyroid hormone, ranging from 21% in the controls to 62% in the moderate uraemia group. In the acute uraemics, parathyroid hormone levels were very high and verapamil did not cause any further elevation of the hormone in the blood. Parathyroidectomy significantly lowered plasma parathyroid hormone, and verapamil resulted in a mean increase of 29%. EDTA caused an increase of 64%, compared with the control group.

Acute Kidney Injury↗
PubMed1986

Pancreatic carcinoma is associated with delayed gastric emptying.

Fifteen patients with histologically confirmed pancreatic carcinoma, without evidence of gastroduodenal invasion or obstruction, were prospectively studied to determine the frequency of gastric emptying disorders as determined by a solid-phase gastric emptying study. Nine of these (60%) had gastric emptying curves more than two standard deviations below normal mean values. The majority of patients did not have symptoms of gastric stasis. Nausea and/or vomiting was present in 33% of patients with abnormal gastric emptying and in none of those with normal emptying. Abdominal and/or back pain was present in 8/9 with delayed gastric emptying and in 3/6 with normal emptying. Disordered gastric emptying did not correlate with tumor stage, histology, location, or hyperbilirubinemia. Delayed solid-food gastric emptying may be responsible for the nonspecific abdominal complaints that occur during the course of pancreatic carcinoma, although more frequently, gastroparesis exists on a subclinical level.

Adenocarcinoma↗
PubMed1986

Acute renal failure in a solitary kidney due to bacterial pyelonephritis.

Deterioration of renal function after acute bacterial pyelonephritis is rare. We report on 2 patients with a solitary functioning kidney in whom acute renal failure developed in the setting of acute bacterial pyelonephritis. Following antimicrobial treatment kidney function returned to baseline values. This finding suggests that patients with a solitary functioning kidney are more prone to have renal dysfunction after acute bacterial pyelonephritis.

Acute Kidney Injury↗
PubMed1986

Serum galactosyltransferase isoenzyme patterns of cancer patients with liver involvement.

The level of galactosyltransferase activity was measured in the serum of 220 patients with a variety of solid tumours. There was a significantly greater proportion of patients with elevated galactosyltransferase in the group with metastatic disease (43%) than for the group with localised disease (16%). Galactosyltransferase was elevated in 69% of patients with liver metastasis compared to 32% of patients with metastatic disease at sites other than liver and this difference was also significant. High resolution agarose isoelectric-focusing was used to determine the 'isoenzyme' pattern of serum galactosyltransferase of 6 patients with liver metastasis and 2 patients with primary hepatoma and these were compared to those of 6 patients with similar primary tumours without liver involvement. There were no qualitative differences in the patterns from the two groups. The average peak height for each of the 19 peaks of activity identified was generally higher in the group with liver involvement, except for those peaks known to contain little or no attached sialic acid. Liver involvement appears not to contribute in any specific way to the altered pattern of serum galactosyltransferase often seen in patients with solid tumours. The tumour rather than the liver is therefore the most likely source of these alterations.

Carcinoma, Hepatocellular↗
PubMed1986

Parathyroid hormone effect on the fragility of human young and old red blood cells in uremia.

Parathyroid hormone (PTH) is elevated in patients with chronic renal failure (CRF) and was suggested to be one of the factors responsible for the anemic syndrome of these patients because it raises the osmotic fragility of the red blood cells (RBC). In the present study, the youngest and oldest RBC were separated from circulating erythrocytes by high-speed centrifugation. The age distribution was described, and the effect of PTH on the different age groups was investigated. Median density (MD) and glutamic-oxaloacetic transaminase (GOT) activity were chosen as age markers. MD (1.0985 +/- 0.00087) and GOT activity (12.49 +/- 2.083 IU/g Hb) of the young uremic cells did not differ significantly from the values of young normal cells (1.0987 +/- 0.00046 and 10.36 +/- 1.174 IU/g Hb, respectively). The MD of the oldest cells, however, was lower (1.1048 +/- 0.00054) and GOT was higher (6.60 +/- 1.1019 IU/g Hb) in the uremic than in the control cells (1.1093 +/- 0.00175 and 3.77 +/- 0.233 IU/g Hb, respectively). These results indicate that the life span of RBC in uremics is shorter than normal and that an enrichment of circulating RBC by young cells occurs in uremic patients. The median osmotic fragility (MOF) of the young cells was lower in both uremic (0.376 +/- 0.006) and control patients (0.378 +/- 0.003) than the MOF of old cells (0.402 +/- 0.005 and 0.392 +/- 0.004, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Aspartate Aminotransferases↗
PubMed1986

Anterior uveitis, a presenting symptom in acute interstitial nephritis.

Two adult women with idiopathic acute interstitial nephritis (AIN) whose presenting symptom was anterior uveitis are described. On histologic examination of the renal biopsy, eosinophilic infiltrates and mononuclear cells were found. Immunofluorescence was negative. Immunological evaluation showed a slight decrease in the number of T cells with a normal subpopulation ratio. AIN responded to steroid treatment.

Acute Disease↗
PubMed1986

Combined tubular dysfunction in medullary cystic disease.

A patient with medullary cystic disease presented with a combined tubular dysfunction, including severe salt wasting, renal tubular acidosis types I and IV, and marked aldosterone resistance. High-dose mineralocorticoid treatment partially corrected the defect in potassium excretion and did not affect natriuresis. Plasma aldosterone level was more than 30 times the upper normal level and was decreased but not normalized by captopril administration and volume expansion. The severe hemodynamic and metabolic consequences of these defects were corrected by renal transplantation.

Acidosis, Renal Tubular↗
PubMed1986

Metabolic acidosis enhances 1,25(OH)2D3-induced intestinal absorption of calcium and phosphorus in rats.

The effect of metabolic acidosis on the intestinal absorption of calcium (Ca) and phosphorus (P), plasma vitamin D metabolites and urinary excretion of Ca in adult rats treated with a small dose of 1,25(OH)2D3 were investigated. The rats in the experimental group received 1.8% ammonium chloride (NH4Cl) and a commercial chow, and their pair-fed controls received 0.45% NaCl. Both groups were given subcutaneously 1,25(OH)2D3. Intestinal absorption of Ca and P was measured by gut sac uptake of 45Ca and 32P. In the acidotic rats, duodenal, jejunal and ileal 45Ca uptake as well as jejunal and ileal 32P uptake were significantly increased. Plasma 1,25(OH)2D, 25(OH)D and 24,25(OH)2D were similar in both groups. 1,25(OH)2D3 treatment induced a greater calciuria in acidotic rats and increased their fractional excretion (FE) of Ca. An additional experiment showed increased 45Ca uptake by duodenum at a pH of 7.0 compared to pH 7.4. The present study suggests that NH4Cl-induced metabolic acidosis may enhance the effect of 1,25(OH)2D3 on intestinal absorption of Ca and P in the rat. However, the data from the study cannot exclude the possibility that acidosis may have a direct, vitamin D-independent effect on the intestine.

Acidosis↗