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Biomedical subjects

O Epstein

Publications and source records attributed to O Epstein.

At least 55 records · Page 3Linked to original sources
PubMed1987

Increased porphobilinogen deaminase activity in patients with malignant lymphoproliferative diseases. A helpful diagnostic test.

Patients with malignant lymphoproliferative diseases, ie, chronic lymphocytic leukemia and lymphoma, were found to have higher porphobilinogen deaminase (PBGD) activity in their peripheral lymphocytes than normal control subjects, patients with other malignant neoplasms, and patients with various infectious diseases. The specificity and sensitivity of the test were 99% and 87%, respectively. The sensitivity of the test was 100% in patients with chronic lymphocytic leukemia and 82% in patients with lymphoma. The diagnostic value of PBGD determinations was shown in a prospective study of a group of patients evaluated because of fever of unknown origin, anemia, or other constitutional symptoms with or without lymphadenopathy or a mediastinal mass. The positive and negative predictive values in these patients were 91% and 100%, respectively. Nearly all patients who were in remission had normal enzyme activity. Lymphocyte PBGD determinations also may be of value in determining when to terminate or reinitiate drug treatment.

Adult↗
PubMed1987

Vitamin E deficiency and its clinical significance in adults with primary biliary cirrhosis and other forms of chronic liver disease.

The vitamin E status of 146 adults with chronic liver disease was assessed by estimating both their serum vitamin E concentration and the ratio of serum vitamin E to serum cholesterol concentration. Low levels of vitamin E occurred most frequently in patients with primary biliary cirrhosis and other forms of chronic cholestatic liver disease. When a serum vitamin E concentration of 12.3 mumol/l (mean-2 SD of a control population) was taken as the lower limit of normal, 44% of patients with primary biliary cirrhosis and 32% with other chronic cholestatic liver disease had a reduced concentration, indicating a biochemical deficiency of vitamin E. If a vitamin E/total cholesterol ratio of 2.35 mumol/mmol was taken as the lower limit of normal, then 64% and 43% of patients with primary biliary cirrhosis and other chronic cholestatic liver disease, respectively, had a biochemical deficiency of vitamin E. Of the patients with chronic cholestasis and a serum bilirubin concentration greater than 100 mumol/l, 91% had a reduced vitamin E/cholesterol ratio. Twelve patients with primary biliary cirrhosis and severe vitamin E deficiency (serum vitamin E less than 5.0 mumol/l and a vitamin E/cholesterol ratio less than 1.0 mumol/mmol) underwent extensive neurological investigation. Five had a mild mixed sensorimotor peripheral neuropathy, which was not, however, typical of the neurological syndrome associated with vitamin E deficiency. In patients with severe biochemical deficiency of vitamin E (less than 5 mumol/l and less than 1 mumol/mmol total cholesterol), administration of large oral doses of vitamin E only increased serum concentrations to within the normal range in one patient; in the others even weekly parenteral administration over a 3-month period did not correct deficiency. In patients with less severe biochemical deficiency, the serum vitamin E concentration and vitamin E/total cholesterol ratio were restored to normal by oral or intramuscular supplements of the vitamin.

Cholestasis↗
PubMed1987

Hyperparathyroidism and low serum osteocalcin despite vitamin D replacement in primary biliary cirrhosis.

Thirty-six patients with primary biliary cirrhosis (PBC) receiving calcium and calciferol supplements (100,000 IU monthly by im injection) were investigated for their calcium, vitamin D, PTH, and osteocalcin status. The corrected plasma calcium concentrations in PBC patients were significantly greater than those in normal subjects. While the mean serum 25-hydroxycholecalciferol and 1,25-dihydroxyvitamin D concentrations in these patients were similar to those in normal subjects, the mean serum PTH concentration was significantly greater, and it was supranormal in 11 patients. Three patients had elevated corrected calcium concentrations; 1 of them had a concomitant increase in ionized calcium and a supranormal PTH level, and another had a high normal PTH. Ionized calcium concentrations were normal in the rest. Serum osteocalcin concentrations were significantly lower in the patients compared with those in normal subjects. These results indicate that PTH concentrations are frequently elevated in PBC patients despite adequate vitamin D supplementation and normal or even supranormal plasma calcium concentrations. Nonsuppression of PTH concentrations and autonomy of PTH secretion suggest that vitamin D deficiency and secondary hyperparathyroidism in such patients probably occur much earlier in the natural history of this disease than is currently realized. Persistent nonsuppressible hypersecretion of PTH probably contributes to the bone disease of primary biliary cirrhosis. The low osteocalcin concentrations probably reflect diminished osteoblastic activity, which may also contribute to osteopenia in these patients.

Adult↗
PubMed1986

Serum immunoreactive trypsin and pancreatic lipase in primary biliary cirrhosis.

Immunoreactive trypsin concentration and pancreatic lipase activity were measured in the sera of 33 patients with primary biliary cirrhosis. Immunoreactive trypsin was increased (above the normal range) in 16 (48%) and pancreatic lipase activity in 18 (55%) patients. Both enzymes were increased in 10 (30%) patients. Twenty four patients (73%) had an increase of either one or both enzymes. There was a significant correlation between immunoreactive trypsin and pancreatic lipase activity. This abnormality was not related to treatment with D-penicillamine, the age of the patients, the stage of the disease, or the severity of cholestasis. Thus most patients with primary biliary cirrhosis have increased pancreatic enzyme activity and immunoreactive trypsin concentration in their sera. These data are indicative of damage to the exocrine pancreas. The cause of this damage is as yet unknown.

Age Factors↗
PubMed1985

Effects of propranolol during pregnancy and development of rats. II. Adverse effects on development.

High doses of propranolol administered to rats during pregnancy and lactation cause inhibition of growth of the neonatal rats. Growth remains inhibited if drug treatment is continued after weaning. Cessation of drug administration after weaning leads to a nearly normal growth rate but a relatively long period elapses before normal weight is attained. The administration of large doses of propranolol to young growing rats also causes inhibition of growth. This inhibition is quickly reversed upon cessation of drug treatment.

Animals↗
PubMed1985

The influence of carbamazepine on the heme biosynthetic pathway.

Carbamazepine, a drug which is widely used in neurological diseases, has a porphyrogenic effect in chick embryo liver cells in culture. It increased the concentration of cellular porphyrins by 80-fold and delta-aminolevulinate synthase activity by 4-fold. The increase in the accumulation of porphyrins preceded that of ALAS activity. Measurements of the activities of aminolevulinate dehydrase, porphobilinogen deaminase, and uroporphyrinogen decarboxylase showed that C inhibits UROD up to nearly 50% and PBGD activity up to 20%, but does not affect the activity of ALAD. The pattern of accumulation of porphyrins, mainly uro- and heptacarboxylporphyrin, is compatible with an inhibition of UROD. We may, therefore, conclude that the porphyrogenic effect of C in monolayers of chick embryo liver cells is the result of its inhibitory effect on the activity of UROD.

5-Aminolevulinate Synthetase↗
PubMed1985

Inhibition of experimental porphyria with colchicine.

Colchicine at the concentrations of 5 X 10(-7) - 5 X 10(-6) M decreased significantly both delta-aminolevulinic acid synthase activity and accumulation of porphyrins in monolayers of chick embryo liver cells induced by allyl-isopropylacetamide, by 3,5-diethoxycarbonyl-1,4-dihydrocollidine or by phenobarbitone. No effect was noted in non-induced cells. In rats, colchicine 0.3 mg/kg, reduced significantly the allyl-isopropylacetamide induced increase in the activity of delta-aminolevulinic acid synthase in the liver and the concentration of urinary porphyrins while it did not affect these parameters in non-induced rats.

5-Aminolevulinate Synthetase↗
PubMed1985

Impairment of induction of delta-aminolevulinic acid synthase by gluconeogenic amino acids and carbohydrates in vitro.

This study was undertaken in a system of chick embryo liver cells incubated in Earle's Basal Salt Solution with hormones. Impairment of induction of delta-aminolevulinic acid synthase (ALAS) by allyl-isopropylacetamide (AIA) was observed in the presence of glucose. Fructose and various gluconeogenic substances including gluconeogenic amino acids had a similar effect. Leucine, which is purely ketogenic, did not influence induction of ALAS. SH-containing amino acids increased induction of ALAS by AIA. The glucose analogues 3-O-methylglucose and 2-deoxyglucose did not impair induction of ALAS by AIA. The inhibitory effect of glycerol, fructose, and glycine was not affected by 3-O-methylglucose but was reversed by 2-deoxyglucose. The results indicate that the salutary effects of proteins on acute attacks of hepatic porphyria are probably caused by their gluconeogenic properties and that glucose-6-phosphate, or metabolite of glucose-6-phosphate that is not in the glycolytic pathway, is the active agent that leads to the glucose-like effect.

3-O-Methylglucose↗
PubMed1985

Evidence of abnormality of lymphocyte uroporphyrinogen synthase in family members of patients with lymphoproliferative diseases.

Patients with active lymphoproliferative diseases (LPD) were shown to have high activity of lymphocyte uroporphyrinogen synthase (L-UROS), the enzyme which converts porphobilinogen to uroporphyrinogen. The mean L-UROS activity of 64 first-degree relatives of patients with LPD was significantly higher than that of a control group and 45% of these relatives had pathological values of L-UROS. L-UROS activity was also determined in the spouses of 2 patients and was pathologically elevated in both. The pattern of pathological values among family members may indicate the presence of a communicable agent.

Adult↗
PubMed1985

The porphyrogenic effects of calcium channel blocking drugs.

Treatment of monolayers of chick embryo hepatocytes with the calcium channel blocking drugs nifedipine and verapamil resulted in a decrease in the activity of uroporphyrinogen decarboxylase, an increase in the activity of delta-aminolaevulinate synthase and accumulation of porphyrins with uroporphyrin and heptacarboxylic porphyrin predominating. Diltiazem, another calcium channel blocking drug, did not affect uroporphyrinogen decarboxylase activity and had a slight effect only on the accumulation of porphyrins. Experiments with nifedipine and verapamil in the presence of various concentrations of calcium indicate that the porphyrogenic effect is apparently not related to blocking of calcium channels.

5-Aminolevulinate Synthetase↗
PubMed1984

The effects of metalloporphyrins, porphyrins and metals on the activity of delta-aminolevulinic acid synthase in monolayers of chick embryo liver cells.

The effect of various metals, porphyrins and metalloporphyrins on the activity of delta-aminolevulinate synthase (ALAS) was measured in monolayers of chick embryo liver cells in order to determine whether the metal moiety of heme or heme itself is the regulator of ALAS activity. Iron, magnesium, zinc, copper, manganese and nickel did not decrease ALAS activity in non-induced and in cells induced by allyl-isopropylacetamide (AIA). Cobalt decreased both non-induced and induced activity. Porphyrins inhibited ALAS, apparently only after having been converted into metalloporphyrins. Almost all the metalloporphyrins examined decreased ALAS activity. None of the substances, at the concentrations used, was toxic to the cells. These observations indicate that probably heme and not iron is the regulator of ALAS activity in monolayers of chick embryo liver cells.

5-Aminolevulinate Synthetase↗
PubMed1984

Bacteriuria and primary biliary cirrhosis.

Significant bacteriuria was found in 19% of 87 women with primary biliary cirrhosis, whereas in 89 women with other types of chronic liver disease bacteriuria was present in only 7%. In 74 women with rheumatoid arthritis 8% were bacteriuric. Midstream urine specimens obtained from 144 consecutive women with primary biliary cirrhosis attending hospital over a two year period showed that 50 (35%) developed bacteriuria during 12 months of follow up. Bacteriuria was unrelated to age, raised serum bilirubin, drug therapy or urinary pH but was more common in patients with late stage (fibrotic) disease as judged by histological criteria. Fifty seven per cent of bacteriuric primary biliary cirrhosis patients suffered more than one urinary infection. Fifty nine per cent of the 156 bacteriuric episodes were asymptomatic. The types of organism isolated, the antibiotic sensitivity patterns and cure rate were similar to those reported in bacteriuric women without other underlying disease. The reinfection rate (34%), however, was double that reported for bacteriuric episodes in 'problem' women with recurrent bacteriuria, indicating a special susceptibility to urinary infection. The most common isolates were E coli (70%), which did not show abnormal adhesiveness to uroepithelial or buccal cells of normal women, or to those of primary biliary cirrhosis patients. Patients with primary biliary cirrhosis have not been reported to be more susceptible to infection in general. Bacteriuria, however, was common throughout all clinical stages of primary biliary cirrhosis. Thus there may be a unique association between bacteriuria and primary biliary cirrhosis.

Adult↗