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Biomedical subjects

B Wolf

Publications and source records attributed to B Wolf.

At least 307 records · Page 17Linked to original sources
PubMed1983

Cheirolumbar dysostosis: a phenotype of pseudohypoparathyroidism.

Cheirolumbar dysostosis is a skeletal dysplasia characterized by brachydactyly and stenosis of the lumbar vertebral canal. Our recent experience with a patient having these clinical features indicates that this condition may be a phenotype of pseudohypoparathyroidism, rather than a distinct entity.

Child↗
PubMed1983

Stain intensity of human nucleolus organizer region reflects incorporation of uridine into mature ribosomal RNA.

The stain intensity of the nucleolus organizer regions (NORs) of acrocentric chromosomes was correlated positively with incorporation of [3H]uridine into 18S rRNA and 28S rRNA from cultured diploid human skin fibroblasts. An analysis of these data from twins by a path model indicated that no other common genetic or environmental parameters were required to explain the relationship between NOR scores and uptake of [3H]uridine into mature rRNA species.

Adolescent↗
PubMed1983

Clinical heterogeneity in 80 home-reared children with cri du chat syndrome.

A population of 80 home-reared children with cri du chat syndrome was investigated to document the clinical heterogeneity of the syndrome and to analyze the factors influencing the severity of the phenotypic characteristics. When individuals with isolated deletions were compared with those possessing unbalanced translocations involving other chromosomes in addition to number 5, the latter group had a greater incidence of physical anomalies, more frequent hospitalizations, and a higher mortality. Chronic complaints in both groups included upper respiratory tract infection, otitis media, and a previously unrecognized association with gastrointestinal tract anomalies. In children with terminal deletions, there was a significant negative correlation between the size of the deletion and the individual's intelligence quotient. In addition, patients with larger deletions had more severe growth retardation, particularly with respect to the degree of microcephaly. The gradual progression with age of the characteristic facial features remained consistent regardless of differing racial backgrounds and the size of the deletion. Our findings delineate the variation in the clinical and karyotypic features of this syndrome.

Adolescent↗
PubMed1983

Phenotypic variation in biotinidase deficiency.

Biotinidase deficiency is the usual biochemical defect in biotin-responsive late-onset multiple carboxylase deficiency. We reviewed the clinical features of six patients with the enzyme deficiency and compared them with features described in the literature in children with late-onset MCD. In all of the reported probands, MCD was diagnosed because they had metabolic ketoacidosis and organic aciduria in addition to various neurologic and cutaneous symptoms, such as seizures, ataxia, skin rash, and alopecia. Although in several of our patients biotinidase deficiency was also diagnosed because they manifested a similar spectrum of findings, others never had ketoacidosis or organic aciduria. Thus the initial features of biotinidase deficiency usually include neurologic or cutaneous symptoms, whereas organic aciduria and MCD are delayed, secondary manifestations of the disease. These findings suggest that biotinidase deficiency should be considered in any infant or child with any of these neurologic or cutaneous findings, with or without ketoacidosis or organic aciduria. If the diagnosis cannot be excluded, such individuals should be given a therapeutic trial of pharmacologic doses of biotin.

Amidohydrolases↗
PubMed1983

Fatty liver and kidney syndrome in chickens as an animal model for Reye's syndrome.

Fatty liver and kidney syndrome (FLKS), a naturally occurring but experimentally reproducible disease in chickens, has several clinical, pathological, and biochemical features in common with Reye's syndrome. Because of this, it has been suggested that FLKS may serve as an animal model of Reye's syndrome. We have examined, therefore, various parameters characteristic of Reye's syndrome in chickens affected with FLKS to further delineate the similarities and differences between the two disorders. Plasma glucose concentrations were significantly lower in chickens affected with FLKS which may be caused by the significantly reduced activity of pyruvate carboxylase in all FLKS-affected animals. The activity of propionyl CoA carboxylase was low in only the most severely affected chickens, and beta-methylcrotonyl CoA carboxylase showed no difference when compared with controls. This may be due to variable sensitivities of the three carboxylases to marginal biotin deficiency which occurs with FLKS. Plasma ammonia concentrations and activities of glutamic oxaloacetic transaminase and glutamic pyruvic transaminase, however, were not elevated in the affected birds. Histological changes in the liver and kidney were noted in affected chickens, but these changes were not identical with those observed in Reye's syndrome. Although the mechanisms of nitrogen elimination in fowl differ from those in humans, failure to demonstrate hyperammonemia, elevated serum transaminase activities, or similar histological changes in tissues of affected birds indicates that FLKS is not an appropriate model for the study of Reye's syndrome.

Ammonia↗
PubMed1983

Three closely linked latent rabbit IgG allotype gene products: a1, d12, e14.

Rabbit latent allotypes in the serum are non-allelic immunoglobulin markers that are transiently expressed in low concentration. In this report we describe the isolation and characterization of a linked series of latent allotypes on the gamma-chain which were found in two rabbits. This latent allogroup contains the determinants a1, d12, e14, which corresponds to the known nominal haplotype I. The latent allogroup is only periodically expressed in the serum and transmitted in a non-Mendelian fashion. However, although only intermittently expressed, both a1 and e14 were found to be displayed in a polyclonal manner by isoelectric focusing. The a1 was associated with the Fab region, the d12 was associated with the hinge region, and the e14 was associated with the Fc region when the peptides were assayed after enzymatic cleavage. The non-allelic demonstration of these genetic markers indicates that each of the rabbits studied carries all the alternative genes for the major three allotypic loci in the gamma-chain. It is possible that other rabbits bear them as well, but they remain "silent" at any given time.

Animals↗
PubMed1983

[Automatic ultramicrotome drive for routine medical histology with the electron microscope].

In modern ultramicrotomes the thermic advance system has been replaced by a mechanical one. Earlier, conventional DC-voltage motors were used, but recently the step motor has become popular. In connection with such motors, the application of digital control elements is facilitated, thus increasing precision significantly. A further step towards improving the precision of the advance system is the application of microprocessors as intelligent and interacting control elements. The microprocessor can not only take over the function sensors, the function of regulation. This paper describes a working concept whereby the advance system does not, as usual, work freely, but in connection with a sensor which measures the advance, and first after a positive data comparison over the microprocessor, allows the cutting movement. The concept is not limited to ultramicrotomes but can also be applied to mechanical rotation microtomes.

Computers↗
PubMed1983

[Uric acid determination in dilute serum with an enzyme electrochemical and enzyme-free sensor].

The paper describes the development of electrochemical methods for analytical determination of uric acid basing on amperometric sensors: with an uricase enzyme electrode, termed "electrochemical-enzymatic" method; with an enzyme-free electrode by indication of the anodic oxidation of uric acid, termed "electrochemical" method. The comparison of analytical quality of both methods shows a sufficient specificity, precision, and accuracy. They show a good correlation with regard to the specific uricase-catalase reference method (UCM): yelectr./enz. = (0.943 xUCM + 19.8) mu mol/l; r = 0.9948 yelectr. = (0.964 xUCM + 6.31) mu mol/l; r = 0.9917 The analysis by the "electrochemical" method can be done with a higher frequency of samples per hour completely without need of enzyme. Both methods are principally suitable for an application in analytic biochemical laboratories.

Electrochemistry↗
PubMed1982

A simple method for the preparation of antibodies to the mitochondrial biotin-dependent carboxylases.

Heterologous antiserum to the 3 biotin-dependent carboxylases was prepared by selective removal of these enzymes from human liver on an avidin-sepharose column. A carboxylase-avidin-sepharose matrix was used as an antigen to produce anti-carboxylase antibodies. The resultant antisera can be used to purify the specific carboxylases, to prepare monoclonal antibodies to these enzymes or to study inherited carboxylase deficiencies and biotin-dependent intermediary metabolism.

Acetyl-CoA Carboxylase↗