Search PubMed⌕ Search

Biomedical subjects

O Sperling

Publications and source records attributed to O Sperling.

At least 109 records · Page 6Linked to original sources
PubMed1979

De novo synthesis of purine nucleotides and metabolic availability of phosphoribosylpyrophosphate in leukemic leukocytes.

Among normal peripheral blood leukocytes, lymphocytes were found to contain most of the de novo purine synthesizing capacity. The rate of purine synthesis de novo was accelerated in leukocytes from patients with acute and chronic myelocytic leukemias, chronic monocytic leukemia, myelofibrosis and plasma cell leukemia, but was normal in most patients with chronic lymphocytic leukemia. The rate of de novo purine synthesis exhibited positive correlation with the percentage of immature cells in the leukocyte population. The metabolic availability of phosphoribosylpyrophosphate (PRPP) exhibited positive correlation with the state of de novo purine synthesis. These finding suggest that the accelerated rate of de novo purine synthesis and the increased metabolic availability of PRPP are characteristic properties of the immature leukemic granulocyte.

Humans↗
PubMed1979

Inborn hypouricemia due to isolated renal tubular defect.

Inborn hypouricemia due to isolated renal tubular defect is a rare disorder. Thus far eight documented families with this condition have been reported. In reviewing the data on these families, hyperuricosuria was found to be a constant associate of the hypouricemia, and hypercalciuria, mainly of the absorptive type, was frequently associated. Urolithiasis appears to be common. The mode of inheritance of this hypouricemia was autosomal, probably recessive. The magnitude of renal urate clearance and the effects on it of probenecid and pyrazinamide suggest the inborn renal hypouricemia to be of two types, due to defective re-secretory tubular urate reabsorption and to total defective tubular urate reabsorption. The question of the renal tubular abnormality for urate transport being the primary defect or secondary to an abnormal metabolite is discussed.

Adult↗
PubMed1978

Regulation of de novo purine synthesis in chick liver slices. Role of phosphoribosylpyrophosphate availability and of salvage purine nucleotide synthesis.

The differences between the uricotelic chick and the ureotelic rat, in the regulation of purine synthesis de novo, were studied in intact liver tissue. Chick liver, in comparison with rat liver, was found to contain a high activity of purine synthesis de novo, a high content and availability of 5-phosphoribosyl 1-pyrophosphate (PP-rib-P), comparable activity of PP-rib-P synthetase, and low activity of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and of adenine phosphoribosyltransferase (APRT). The results suggest that the intensive activity of the pathway of purine synthesis de novo in the chick liver is mediated by the high PP-rib-P concentration, which may be due at least in part to the relative partial deficiency of HGPRT.

Adenine↗
PubMed1978

Some regulatory properties of purine biosynthesis de novo in long-term cultures of epithelial-like rat liver cells.

De novo synthesis of purine nucleotides and some regulatory properties of this pathway were studied in cultured epithelial-like rat liver cells. It was found that the physiological 5-phosphoribosyl 1-pyrophosphate (P-Rib-PP) concentration in these cells is limited for purine synthesis de novo. Increase of P-Rib-PP availability, achieved by activation of P-Rib-PP synthetase at high Pi concentration, resulted in acceleration of purine synthesis. The effects of increasing cellular ribose 5-phosphate (Rib-5-P) availability, by methylene blue-induced acceleration of the oxidative pentose phosphate pathway, on P-Rib-PP availability and on the rate of the novo purine synthesis were also studied. It was found that at the Pi concentration prevailing in the tissue at extracellular physiological Pi concentration, Rib-5-P availability is saturating for P-Rib-PP generation and therefore also for purine synthesis.

Animals↗
PubMed1978

Urine xanthine oxidase activity in urinary tract infection.

Xanthine oxidase (XO) activity was found to be negligible in sterile human urines (less than 480 units, as presently defined, per litre). Significant XO activity was found in all urines containing more than 10(5) bacteria/ml, except for urines infected with Staphylococcus aureus, in which XO activity ranged from 347 to 714 units per litre. Plasma XO is not transferred to the urine, as demonstrated by the negligible XO activity found in sterile urines from patients with raised plasma XO activity. Determination of urinary XO activity is a suitable procedure for the detection of urinary tract infection.

Bacteriuria↗
PubMed1978

Overproduction disease in man due to enzyme feedback resistance mutation. Purine overproduction in gout due to excessive activity of mutant feedback-resistant phosphoribosylpyrophosphate synthetase.

Physiologically superactive phosphoribosylpyrophosphate (PRPP) synthetase, due to feedback resistance mutation, was found in a family with excessive purine production, gout and uric acid lithiasis. The superactivity of the mutant enzyme was manifest in the propositus' erythrocytes and cultured fibroblasts, in increased generation, content and metabolic availability of PRPP, leading in the fibroblasts to acceleration of the rate of purine synthesis de novo. One of the propositus' two siblings was similarly affected, but the propositus' father, his second brother and four sons, were all clinically and biochemically normal. The mother was clinically normal and normouricemic, but hyperuricosuric. Cultured fibroblasts from her skin exhibited variability in PRPP content and availability and in the rate of purine synthesis de novo. The mother's cultures were found to contain a mosaicism of two cell populations, one with normal and the other with mutant PRPP synthetase, indicating an X-linked pattern of inheritance of the PRPP synthetase abnormality in this gouty family.

Adolescent↗
PubMed1978

Familial hypouricemia due to isolated renal tubular abnormality.

A family with genetic hypouricemia due to isolated renal tubular abnormality in urate handling is reported. Urinary urate excretion was decreased by 61% following administration of pyrazinamide, and increased by 25% following administration of probenecid. The response to these drug suggest genotype heterogeneity of renal hypouricemia in man.

Chromosome Aberrations↗
PubMed1977

Effect of methoxyflurane anesthesia on serum uric acid in man.

Serum uric acid levels were significantly increased on the first and third postoperative days following methoxyflurane anesthesia in subjects undergoing various surgical procedures. The increment on each of these days was significantly correlated with the duration of the anesthesia. No such changes were found following halothane or nitrous oxide-oxygen and relaxant anesthesia.

Halothane↗