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R Casey

Publications and source records attributed to R Casey.

At least 109 records · Page 6Linked to original sources

The molecular basis for the two different clinical presentations of classical pyruvate carboxylase deficiency.

Eight cases of isolated human pyruvate carboxylase deficiency were examined from seven families. Although all patients presented with a chronic lacticacidemia, two particular patients presented with the added features of hyperammonemia, citrullinemia, and hyperlysinemia. When cultured skin fibroblasts from these patients were examined for their ability to synthesize [3H]biotin-containing proteins, it was found that the two patients who presented with hyperammonemia, citrullinemia, and hyperlysinemia did not synthesise a protein of the correct subunit molecular weight (Mr = 125 K daltons) corresponding to pyruvate carboxylase. In addition, when skin fibroblast proteins were labeled with [35S]methionine, cross-reacting material (CRM) corresponding to pyruvate carboxylase was immunoprecipitated by antipyruvate carboxylase antiserum in most patients, but again the two patients with the atypical presentation showed no CRM. We propose that the different clinical presentation of human pyruvate carboxylase deficiency is a manifestation of two different mutations in the pyruvate carboxylase gene, one that results in the synthesis of a relatively inactive pyruvate carboxylase protein CRM(+ve) and one that results in the lack of expression of the gene in the form of a recognizable protein CRM(-ve).

Biotin↗

Effective depth of spermatogonia in man I. Measurement of scrotal thickness.

Dosimetry for sperm cells irradiated by high-energy betas requires precise knowledge of the effective depth of the spermatogonia, and hence the thickness of overlying tissues (scrotum plus tunics), because beta dose rate changes very rapidly with depth. Measurements were made on 25 volunteers and surgical patients by mechanical caliper during surgery (2), by ultrasound (14), or by both (9), all at 20 degrees C air temperature. The tunica albuginea (TA) measured 0.1 mm. The surgical results (TA excluded) were 2.0 mm, sigma = 0.3 mm (n = 11). The ultrasound results (TA included) were 2.2 mm, sigma = 0.6 mm (n = 23). There was no correlation of scrotal thickness with age (24-83 years) and only a very weak correlation (r = 0.3) with body mass. There was no decrease in scrotal thickness (at 20 degrees C) with further warming but there was an increase (to 3.3 mm from 2.3 mm) with chilling before measurement. Ultrasound is shown to be valid for such measurements.

Adult↗

The amino acid sequences of the tryptic peptides of cowpea chlorotic mottle virus protein.

The amino acid sequences of the major tryptic peptides from the coat protein of wild type cowpea chlorotic mottle virus are presented. The sequences have been determined by a combination of enzyme hydrolysis, mass spectrometry and Edman degradation, and the relative usefulness of mass spectrometry in this peptide sequence determination is discussed.

Amino Acid Sequence↗

Haemoglobin K Woolwich: a study of the family of a homozygote.

A family is described in which the proband is homozygous and several relatives are heterozygous for Hb K Woolwich (beta 130 [H10] Lys leads to Gln). These people are clinically and haematologically normal. The relationship between the presence of Hb K Woolwich and beta +-thalassaemia is discussed. The distribution of Hb K Woolwich in West Africa is discussed and it is seen to be closely associated with the Akan group.

Adolescent↗

Liver abnormalities in three patients with fetal alcohol syndrome.

Liver abnormalities were found in three patients with fetal alcohol syndrome. The histological appearance was different in each case. Thick, sclerotic central veins were seen in two of the three cases. One patient had features typical of congenital hepatic fibrosis and cystic disease of the kidneys. Findings in these patients indicate that some cases of congenital hepatic fibrosis might be caused by high maternal alcohol ingestion in pregnancy.

Adolescent↗

Immunoaffinity chromatography as a means of purifying legumin from Pisum (pea) seeds.

The potential of immunoaffinity chromatography as a means of purifying legumin from a wide range of Pisum (pea) types was assessed. The method required small amounts of highly purified legumin from a single Pisum type, and this was obtained by salting out with (NH4)2SO4 followed by zonal isoelectric precipitation, ion-exchange chromatography on DEAE-cellulose and sucrose-density-gradient centrifugation. Some physiocochemical properties of purified legumin were determined, a number of which (Strokes radius, subunit molecular weights, subunit N-terminal residues and subunit molar ratios) have not previously been reported for Pisum legumin. Examination of Pisum legumin by two-dimensional gel isoelectric focusing/electrophoresis indicated the existence of extensive subunit heterogeneity, and polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate showed apparent variation in the nature of this heterogeneity from one Pisum variety to another. Despite this variation, immunoaffinity chromatography on immobilized anti-legumin (which was prepared by affinity chromatography on the immubolized purified legumin from the single Pisum type) was shown to be a generally applicable method for the purification of undegraded legumin from a range of pisum types, including two primate lines.

Amino Acids↗

Difficulties and pitfalls in the interpretation of screening tests for the detection of inborn errors of metabolism.

A review of factors which may be responsible for false positive and false negative results in a screening program for the detection of inborn errors of metabolism is presented. Administration of medication, dietary therapy, chemical treatment of specimens, delay in analysis, hypersensitivity of procedures utilized, interfering metabolites and inadequate metabolic development or enzymatic maturation in the patient may all produce results resembling an actual inborn error of metabolism. Inadequate nutritional intake prior to procurement of specimen and loss of material during analytical procedures may produce false negative results. As well, certain less severe variants of inborn errors may present in an unusual manner or may only present during periods of stress to the patient. These factors are discussed in relation to the performance of a metabolic screening program. It is suggested that these progrms should be performed by specialized, central laboratories experienced in the complexities of detection of inborn errors of metabolism.

Anticonvulsants↗

Tryptic hydrolysis at asparagine residues in globin chains.

Commercially available Tos-PheCH2Cl-treated or untreated bovine trypsin (EC 3.4.21.4) is shown to catalyse minor tryptic hydrolysis at the carboxyl side of asparagine residues in globin chains. This activity is not removed by the purification of enzyme, using CM-cellulose chromatography and subsequent affinity chromatography on trypsin inhibitor columns, neither is it inhibited by Tos-PheCH2Cl treatment of the CM-cellulose purified enzyme. It is suggested that the ability to hydrolyse globin chains at asparagine residues may represent an inherent feature of the trypsin molecule.

Amino Acid Sequence↗

Residues 124 and 125 (H2 and H3) of the human haemoglobin delta-chain.

Residues 124 and 125 of the beta-chain of human haemoglobin are prolyl-prolyl. In the delta-chain, one of these positions is occupied by a glutaminyl, and there has been uncertainty as to which of the two residues is the prolyl and which the glutaminyl. The sequence has now been established to be delta124 Pro - 125 Gln.

Amino Acid Sequence↗