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Biomedical subjects

M Smith

Publications and source records attributed to M Smith.

At least 1,315 records · Page 73Linked to original sources
PubMed1978

Reduction in urinary oxalate values by allopurinol.

A variety of substances have been used to prevent recurrence of stone disease. Recently there has been considerable interest in the ability of allopurinol to prevent stone recurrence. This article discusses the effect of allopurinol on the urinary oxalate in a group of stone formers. A significant reduction was obtained especially in subjects in whom the blood urate levels exceeded 300 mumol./L. Possible mechanisms explaining the mode of action of the drug are discussed.

Adult↗
PubMed1978

Identification and isolation of the yeast cytochrome c gene.

The iso-1-cytochrome c gene of yeast has been identified and cloned using a synthetic oligodeoxynucleotide as a hybridization probe. The oligomer d[pT-T-A-G-C-A-G-A-A--C-C-G-G] is complementary to a region near the N terminal coding region of the yeast cyc 1 gene. Of several yeast Eco RI fragments which hybridize to this probe, one is changed in size by a G leads to T mutation which eliminates an Eco RI site within the cyc 1 gene. Both the wild-type and the RI- mutant forms were cloned in lambda gt vectors. Maxam-Gilbert sequencing for 91 nucleotides into the coding region for iso-1-cytochrome c yielded a DNA sequence in perfect correspondence with the known protein sequence.

Base Sequence↗
PubMed1978

A series of hexahydro[1,4]oxazino[3,4-a]isoquinolines as potential neuroleptics.

The synthesis and stereochemistry of trans-N,N-diethyl-9,10-dimethoxy-1,3,4,6,7,11b-hexahydro[1,4]oxazino[3,4-a]isoquinoline-3-carboxamide hydrochloride (16) and a series of analogues are described. 16 and its (+) isomer had neuroleptic properties in the Sidman avoidance test in gerbils. A few closely related amides of the trans series were active but cis amides were inactive as neuroleptics.

Animals↗
PubMed1978

Location of the genes for human heavy chain immunoglobulin to chromosome 6.

Immunoglobulin synthesis was examined in 31 man-mouse hybrid clones produced by fusing RAG mouse cells with human lymphoid cells. Cells were grown in serum-free medium containing [(14)C]leucine and a (14)C-labeled amino acid mixture. Spent medium was dialyzed, concentrated, and subjected to radioimmunoelectrophoresis. Eighteen clones were found to produce material that gave a radiolabeled precipitin line with anti-human IgG (gamma-chain specific). Production of material which was indistinguishable on radioimmunoelectrophoresis from human Ig gamma heavy chain, was dependent on the presence in hybrid clones of human chromosome 6. The material was found to have the ion-exchange elution characteristics of human IgG. When radiolabeled spent medium from human lymphoid lines and from chromosome 6-positive hybrid clones was exposed to protein A-Sepharose and bound material eluted with 8 M urea was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis, three radiolabeled peaks occurred with molecular weights of approximately 55,000 (coinciding with that of Ig gamma heavy chain), 40,000 and 25,000 (coinciding with that of Ig light chains). No similar peaks were detected in experiments where spent medium from RAG cells was treated identically. These studies lead us to conclude that certain RAG-human lymphoid hybrid clones produce human IgG and that the structural genes for gamma heavy chains are located on human chromosome 6. These results also imply that the locus coding for human alpha,-antitrypsin (Pi) is located on chromosome 6.

Cell Line↗
PubMed1978

Enzymatic synthesis of oligodeoxyribonucleotides of defined sequence. Polynucleotide phosphorylase catalysed addition of deoxyribonucleotides to primers which are good or poor acceptors.

Analytical high-pressure anion-exchange chromatography on RPC-5 has been used to study the behaviour of a good primer, d(pT-T-A-G), and a poor primer, d(pT-T-T-T-T-T) in the E. coli polynucleotide phosphorylase-catalysed reactions of dADP, dCDP, dGDP and dTDP where the primer is extended, predominantly, by one or two nucleotides. The experiments provide some generalizations for obtaining optimal yields in preparative reactions. In the course of the experiments, examples of anomalous behaviour of oligonucleotides on RPC-5 were encountered and these are discussed.

Base Sequence↗
PubMed1978

Enzymatic synthesis of oligodeoxyribonucleotides of defined sequence. Polynucleotide phosphorylase catalysed synthesis using pyrimidine analog-containing deoxyribonucleoside 5'-diphosphates.

The E. coli polynucleotide phosphorylase-catalysed reaction of the deoxynucleoside 5'-diphosphates of 5-methyldeoxycytidine, N4-hydroxydeoxycytidine, deoxyuridine and 5-mercurideoxyuridine with the primers d(pT-T-A-G) and d(pT-T-T-T-T-T) have been studied under conditions where the primer is extended, predominantly, by one or two nucleotide residues. In experiments with 5-mercurideoxyuridine 5'-diphosphate, no 5-mercurideoxy-uridine-containing oligonucleotides were produced. The other three nucleotide analogs were found to be good substrates for E. coli PNPase and the conditions established for synthesis with these analogs will allow the construction of a number of biologically useful types of oligodeoxyribonucleotide.

Chromatography, High Pressure Liquid↗
PubMed1978

Behavioral effects of trace and subanesthetic halothane and nitrous oxide in man.

Using tests of complex reaction time and of immediate recall (digit span), the authors could not demonstrate that trace concentrations of halothane (to 0.02 per cent, or 200 parts per million) or halothane plus nitrous oxide (0.002 per cent plus 0.05 per cent, respectively) or nitrous oxide alone (0.4 per cent) affected mental function of male volunteers. However, subanesthetic concentrations of both nitrous oxide (20 to 30 per cent) and halothane (0.2 per cent) did impair mental function.

Adult↗
PubMed1978

The effect of allopurinol on urinary oxalate excretion in stone formers.

Allopurinol is a drug which could be valuable in the treatment of stone patients. In 29 subjects treated with 300 mg of the drug per day it has been found that there was a significant fall in urine oxalate excretion if the blood urate was above 330 mumol/l. In 10 subjects followed for 1 year the urine oxalate was significantly reduced and maintained at a lower level than the original.

Allopurinol↗
PubMed1978

Some psychological, educational and criminological variables related to recidivism in delinquent boys.

The HDHQ, 16 PF and PSI were administered to 315 detainees at Medomsley Detention Centre, Durham, along with tests of intelligence and attainment, and measures of previous criminal history. One hundred and ninety-one boys were subsequently reconvicted within two years of their release. They were found to have lower scores on reading and arithmetic tests, to show a greater degree of extrapunitive hostility and to score more highly on tests of social non-conformity. Recidivists had also begun their criminal careers at an earlier age than non-recidivists and had committed significantly more previous offences.

Achievement↗
PubMed1978

The natural history of periodontal disease in man. The rate of periodontal destruction before 40 years of age.

This longitudinal study of randomly selected Norwegian students and academicians has shown that 50% of the 17-year olds have lost no periodontal support, and the other 50% exhibited slight localized loss of attachment primarily on buccal surfaces of first molars and first bicuspids of both jaws. At 21 all students show one or more of these lesions as well as loss of attachment on interproximal surfaces. At 30 years of age the mean cumulative loss is still less than 1 mm. As they approach 40 years of age the mean individual loss of attachment is slightly above 1.5 mm or 10% of the total periodontal support, and the mean annual rate of attachment loss is 0.08 for interproximal surfaces and 0.1 mm for buccal surfaces. No case of juvenile periodontitis (periodontosis) or adult aggressive periodontitis were seen in this population. Seventy percent of the 15-year-old Sri Lankans have no or very little loss of periodontal support. However, approximately 30% exhibit localized lesions measuring between 2 and 9 mm and more than 1% have one or more root surfaces with 10 mm loss of attachment or more. In this age group the lesions occur at the interproximal and buccal aspects of lower central incisors and in first molars of both jaws. At 30 years of age the mean loss of attachment is 3.11 mm and approximately 25% of the tea laborers have lesions extending 10 mm or more below the cemento-enamel junction. As the Sri Lankan approaches 40 years of age the mean loss of attachment is 4.50 mm and the mean rate of progress of the lesion is 0.20 mm per year for buccal surfaces and 0.30 mm for interproximal surfaces. This study suggests that without interference the periodontal lesion progresses at a relatively even pace and that the progress is continuous.

Adolescent↗