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Biomedical subjects

B Wolf

Publications and source records attributed to B Wolf.

At least 325 records · Page 18Linked to original sources
PubMed1982

Biochemical characterization of propionyl CoA carboxylase deficiency: heterogeneity within a single genetic complementation group.

Liver tissues and fibroblasts from patients with propionic acidemia assigned to the pcc BC genetic complementation group have previously been shown to contain normal or near-normal quantities of structurally altered propionyl CoA carboxylases (PCC). Biochemical comparisons of PCCs from extracts of three livers and one placenta belonging to the pcc BC complementation group revealed that the Km values for the enzyme's major substrates, propionyl CoA, bicarbonate, and ATP, and its monovalent activator, potassium, were similar to those of normal PCC. PCC in extracts of one of the livers, however, had an altered isoelectric point (pI = 5.4) compared to that of PCC from normal and other PCC-deficient tissues (pK = 4.6-4.7). Thermostability in the presence of sucrose or ATP differed among several of the mutant PCCs, including the PCC with an altered pI, and from that of normal PCC. To confirm these results and to determine whether valid inferences may be derived from comparisons of mutant and normal PCC in crude extracts, PCC was purified from normal liver and from one of the PCC-deficient livers. The biochemical parameters of the purified carboxylases were similar to those observed in liver extracts. These studies furthermore confirmed that, whether purified or in extracts, PCC from the pcc BC group reflects structural mutations. Nevertheless, the abnormal enzyme structure appears to have no corresponding effect on the clinical features of the disorder in various affected individuals. Moreover, there is biochemical heterogeneity within the pcc BC complementation group that probably represents different interallelic gene mutations.

Acyl Coenzyme A↗
PubMed1982

Kinematic analysis of the role of the finger tendons.

In an earlier paper (Storace and Wolf, 1979), the functional anatomy of the finger was studied by considering the equilibrium of tendon forces and externally applied forces. The current work presents an alternative approach which studies the finger's functional anatomy from a kinematic viewpoint. This approach, based on measured tendon displacement, can be used to graphically display the criteria for which normal finger function will exist. Examples of the application of this procedure to normal and non-normal finger conditions are presented to demonstrate its utility.

Biomechanical Phenomena↗
PubMed1982

Age-related decrease in the activity of UDP-xylose:core protein xylosyltransferase in rat costal cartilage.

The activity of UDP-xylose:core protein xylosyltransferase (EC 2.4.2.26) in costal cartilage of young rats (3 months) and old rats (36 months) was measured. The enzyme activity in cartilage of young rats (mean +/- S.D.) is 3370 +/- 1440 Bq h-1 mg-1 DNA, which is about three times higher than that determined in cartilage of old rats (1090 +/- 520 Bq h-1 mg-1 protein). The amount of galactosamine-containing proteoglycosaminoglycans that are extractable with 4 M guanidinium chloride from cartilage is significantly higher in young rats (29.1 +/- 4.8 nmol GalN per mg cartilage wet weight) than in old animals (5.8 +/- 3.0 nmol GalN per mg cartilage wet weight). Thus, if xylosyltransferase activity is referred to the amount of galactosamine-containing proteoglycans in cartilage, nearly identical values are obtained (young rats, 80 +/- 30 Bq h-1 mumol-1 GalN; old rats, 85 +/- 35 Bq h-1 mumol-1 GalN). The results support the assumption that the synthesis of proteochondroitin sulfate is diminished in costal cartilage of old rats by a mechanism involving a reduced activity of xylosyltransferase.

Aging↗
PubMed1982

Magnesium and magnesium adenosine triphosphate activation of human propionyl CoA carboxylase and beta-methylcrotonyl CoA carboxylase.

Free magnesium and MgATP2- are required for activation of the mitochondrial enzymes pyruvate carboxylase, propionyl CoA carboxylase and beta-methylcrotonyl CoA carboxylase. Previous studies have demonstrated that free Mg2+ interacts with either a Mg2+- binding site or one of the two MgATP2- sites that are required for the allosteric activation of pyruvate carboxylase. We have shown that similar Mg2+ and MgATP2- interactions occur to activate propionyl CoA carboxylase and beta-methylcrotonyl CoA carboxylase. Thus, Mg2+ and MgATP2- activation, because it is common to structurally similar carboxylases, may constitute a general mode of carboxylase activation.

Adenosine Triphosphate↗
PubMed1981

Deficient acetyl CoA carboxylase activity in multiple carboxylase deficiency.

Multiple carboxylase deficiency has previously been characterized by deficient activity of three biotin-dependent enzymes: propionyl CoA carboxylase, pyruvate carboxylase and beta-methylcrotonyl CoA carboxylase. We have demonstrated that the activity of a fourth carboxylase, acetyl CoA carboxylase (ACC), is also deficient in fibroblasts from two patients with this disorder. Furthermore, ACC activity increased six- to eight-fold when cells from these patients were incubated in culture medium containing supplemental biotin. If the primary defect in multiple carboxylase deficiency is due to deficient activity of holocarboxylase synthetase, our results would indicate that there may be a common holocarboxylase synthetase, or at least a common subunit, for all the carboxylases. Finally, since ACC catalyzes the initial step in fatty acid biosynthesis, our results further suggest the importance of dietary supplementation with fatty acids in addition to treating these patients with pharmacologic doses of biotin.

Acetyl-CoA Carboxylase↗
PubMed1981

Spondylocostal dysostosis associated with anal and urogenital anomalies in a Mennonite sibship.

Spondylocostal dysostosis, anal atresia, and urogenital anomalies were observed in two male infants of a consanguineous Mennonite couple. A careful review of previously reported syndromes of severe vertebral abnormalities and/or imperforate anus suggests that our patients have a previously undescribed recessive disorder that should be included in the differential diagnosis of rib and vertebral anomaly syndromes.

Anus, Imperforate↗
PubMed1981

Propionyl coenzyme A carboxylase deficiency presenting as non-ketotic hyperglycinaemia.

A 4-month-old girl presented with myoclonic seizures and an electroencephalogram showing hypsarrhythmia. Hyperglycinuria and a cerebrospinal fluid to plasma glycine ratio of 0.2 suggested the diagnosis of non-ketotic hyperglycinaemia. Propionic acid and methyl citric acid were present in the urine, and propionyl coenzyme A carboxylase was deficient in leucocytes and fibroblasts. The ketotic and non-ketotic hyperglycinaemias cannot be differentiated by CSF: plasma glycine ratios.

Carboxy-Lyases↗
PubMed1981

Polar types of reported drug involvement among Israeli youth.

The predisposing factors lined to drug involvement may be different for various types of youth, although the outcome is the same. In this sense a bimodal curve of drug involvement would indicate two types of highly involved youth: on the one hand, those from high social status families where low parental control implies a tendency to seek involvement with their peers and solve their personal adjustment problems within the peer group. On the other hand, those from the lower social strata for whom low parental control also implies association with outside peer groups as an alternative to shaky and diffuse families and lack of involvement in school life. This study on the cannabis involvement of 776 boys and girls (aged 14-18), drawn from eight schools, is an attempt to identify and describe these polar types of drug-involved youth in more detail.

Adolescent↗
PubMed1981

Multiple carboxylase deficiency: clinical and biochemical improvement following neonatal biotin treatment.

Multiple carboxylase deficiency is characterized by deficient activities of three biotin-dependent enzymes, propionyl coenzyme A carboxylase, pyruvate carboxylase, and beta-methylcrotonyl coenzyme A carboxylase. A newborn infant was seen with metabolic ketoacidosis, hyperammonemia, organic aciduria, seizures, and coma. Multiple carboxylase deficiency was subsequently confirmed by enzyme activity determinations in his peripheral blood leukocytes and cultured skin fibroblasts. The infant's neurologic and metabolic status improved markedly within a few days of administration of pharmacologic doses of oral biotin. His EEG, which was distinctly abnormal, became normal; his extensive computed tomography scan changes resolved, with the exception of ventricular dilation, over the next two months. After two weeks of biotin treatment the excretion of abnormal organic acid metabolites was reduced and his carboxylase activities increased to the normal range. However, the activities of these enzymes increased only to 30% to 55% of normal in fibroblasts incubated in supplemental biotin. This partial correction of enzyme activity differs from that observed in other individuals with multiple carboxylase deficiency and suggests biochemical heterogeneity in this disorder. Prompt diagnosis and intervention can avert some of the pathologic complications of this biotin-responsive condition.

Biotin↗
PubMed1981

Biochemical characterization of biotin-responsive multiple carboxylase deficiency: heterogeneity within the bio genetic complementation group.

Three biotin-dependent enzymes, pyruvate carboxylase (PC), propionyl CoA carboxylase (PCC), and beta-methylcrotonyl CoA carboxylase (beta MCC), were biochemically characterized in fibroblasts from two patients with neonatal multiple carboxylase deficiency. Genetic complementation analyses indicated that both cell lines, designated lines 1 and 2, were deficient in the various carboxylase activities and belonged to the bio complementation group. The activities of the three carboxylases became normal when line 2 cells were incubated in medium supplemented with biotin (1 mg/l) for 24 hrs, whereas 4-6 days were required to achieve maximum activities of PC, PCC, and beta MCC (57%, 46%, and 29% of mean normal enzyme activity, respectively) in line 1 cells incubated in medium containing up to 10 mg/1 biotin. Furthermore, PC activity in line 2 continued to increase under apparent gluconeogenic conditions in culture, but not in line 1. Thermostability studies suggested that biotin stabilizes PC and beta MCC in both cell lines. PC in line 1 cells incubated with or without biotin was less stable than that in normal or line 2 cells, and the less than normal increase of enzyme activities in line 1, especially that of PC, may represent incomplete biotination. These results indicate that there is biochemical heterogeneity within the bio complementation group. Immunotitration with antibodies prepared against purified pig heart PCC demonstrated normal quantities of cross-reacting material in both lines and no differences in the amount of this material after incubation with supplemental biotin, despite the seven- to 20-fold increase in PCC activity. Thus, the increase in carboxylase activity in both bio lines appears to represent activation of rpe-existing apocarboxylase rather than de novo enzyme synthesis. The primary defect in this form of multiple carboxylase deficiency may be in a common holocarboxylase synthetase or in biotin transport. If the defect is in the synthetase, the differences noted between the two bio lines could be explained by a difference in the enzyme's Km for biotin.

Biotin↗
PubMed1981

Expression of cell-surface latent allotypes: latent specificities are synthesized only by cells that display the nominal allotype.

The association of latent and nominal allotypes at the cell surface of rabbit peripheral blood lymphocytes (PBL) was studied in animals from 2 closed group colonies. The specificity of the anti-allotype antibodies used in the mixed antiglobulin rosette test was confirmed by radioimmune assay and by testing PBL from latent allotype-free homozygotes. PBL from rabbits exhibiting latent group a and b allotypes were treated with pronase to bring the rosetting population down to less than 1 to 2%; latent and nominal cell-surface allotypes were then regenerated overnight in serum-free culture. Latent and nominal allotypes were detected in the same cell in 16 to 57% of the total allotype-bearing population. The remaining cells displayed only nominal allotype. This was observed in rabbits bearing latent a1, a2, a3, b4, b5, and b6. Rosette-inhibition data indicated that some of the group a latent and nominal allotypes were contiguously associated at the cell surface but that the group b latent and nominal markers were spaced further apart. In addition, in rabbits exhibiting 2 latent group b allotypes, both single and double latent cell surface expression was seen. Rabbits from the Philadelphia and N.I.H. internally derived colonies gave similar results.

Animals↗
PubMed1980

Immunological studies of propionyl CoA carboxylase in livers and fibroblasts of patients with propionic acidemia.

Antiserum prepared against homogeneous pig heart propionyl CoA carboxylase cross-reacted with human propionyl CoA carboxylase, and was used to demonstrate the presence of immunological cross-reacting material in extracts from the livers of three patients and from fibroblasts of four patients with propionic acidemia representing three major propionyl CoA carboxylase-deficient genetic complementation groups, pcc A, pcc C and bio. Since the quantity of cross-reacting material in the propionyl CoA carboxylase-deficient livers and enzyme-deficient fibroblast cell lines was comparable to that in normal tissues while showing less than five percent of the normal enzyme activity, these patients must synthesize normal or near-normal quantities of an enzymatically inactive propionyl CoA carboxylase protein. In addition, no appreciable change in the amount of cross-reacting material was found in the biotin-responsive bio fibroblasts after incubation with supplemental biotin despite a sixteen-fold increase in enzyme activity suggesting that the defect in the bio mutant involves the activation rather than the synthesis of a pre-existing normal apoenzyme.

Animals↗
PubMed1980

Evidence for two genetic complementation groups in pyruvate carboxylase-deficient human fibroblast cell lines.

We have examined genetic complementation in pyruvate carboxylase deficiency by comparing the enzyme activity in polyethylene glycol-induced heterokaryons with that in unfused mixtures of fibroblasts from three affected children. Complementation, manifested as a three- to sevenfold increase in pyruvate carboxylase activity, was observed in fusions between a biotin-responsive multiple carboxylase (pyruvate carboxylase, propionyl CoA carboxylase, and beta-methylcrotonyl CoA carboxylase) deficient fibroblast line and two other lines deficient only in pyruvate carboxylase activity. Kinetic analysis of complementing pyruvate carboxylase deficient lines, measured by the rate of restoration of enzyme activity as a function of time, revealed that maximum restoration was achieved within 10-24 hr after fusion. This profile is similar to those oberved for fusions between the multiple carboxylase deficient line and two lines deficient in propionyl CoA carboxylase activity that are known to represent different gene mutations. Although the patients with pyruvate carboxylase deficiency had similar clinica findings, our studies indicate that pyruvate carboxylase deficiency is genetically heterogeneous, with at least two distinct, probably intergenic, complementation groups.

Biotin↗