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Biomedical subjects

J M Goddard

Publications and source records attributed to J M Goddard.

At least 37 records · Page 2Linked to original sources
PubMed1986

Onchocerciasis in Sierra Leone. I. Studies on the prevalence and transmission at Gbaiima village.

A longitudinal survey--parasitological, clinical, immunological and entomological--of onchocerciasis is being conducted in Gbaiima village in Sierra Leone. The estimated Annual Transmission Potential (ATP) is 5863. More than 80% of the annual transmission occurs between October and December. Four species of the Simulium damnosum complex are known to breed in a nearby river. The relative role of these species as vectors has yet to be determined. The total population (598 persons) aged one year and over were examined. Based on microfilarial and nodular rates the prevalence of onchocerciasis was 68.6%. In persons above 15 years of age this prevalence was 88.9%. Microfilarial and nodular rates were related to age. Severe skin lesions occurred in 1.0% of persons. 24 adults (7.5%) were blind (but the cause of the blindness was not determined).

Adolescent↗
PubMed1986

Surface components of Onchocerca volvulus.

A technique employing Sephadex G25 gel filtration has been developed for the rapid isolation and purification of live microfilariae of Onchocerca volvulus from subcutaneous nodules and skin samples. Microfilariae, adult worms and L3 larvae have been surface radiolabelled using the Iodogen technique. Two proteins have been characterised on the surface of uterine microfilariae: these have apparent molecular weights of 14,800 and 15,000. A MW 15,000 protein was the only molecule labelled on the surface of skin microfilariae. Ten proteins were labelled on adult male worms: these have molecular weights of 15,000, 17,500, 20,000, 22,000, 24,000, 29,000, 32,000, 37,000, 42,000, and 50,000. Some, if not all, of these proteins were also identified on female worms. Seven proteins were labelled on the surface of L3 larvae: these have molecular weights of 17,500, 48,000, 50,000, 52,000, 54,000, 57,000, and 105,000. Three of the adult surface proteins were precipitated by selected human infection serum: these are the MW 17,500, 32,000 and 42,000 molecules. The microfilarial surface proteins were not precipitated by human infection serum. The antiserum used in these experiments was shown by Western blot analysis to contain high levels of antibody with specificity for microfilarial and adult antigens. Indirect immunofluorescent assays showed these sera to contain antibody which bound to the surface of adult worms and eggs but not microfilariae. The possibility that skin microfilariae absorb host serum albumin was investigated: Western blot analysis and surface immunofluorescence assays using a specific anti-human albumin serum gave negative results. Fluorescent lectin binding studies revealed the presence of stage-specific carbohydrate moieties exposed on the surface of adult worms and eggs. Microfilariae do not have surface carbohydrate determinants.

Animals↗
PubMed1986

Isolation and characterization of Caenorhabditis elegans DNA sequences homologous to the v-abl oncogene.

DNA sequences homologous to the v-abl oncogene were isolated from a Caenorhabditis elegans genomic library by their ability to hybridize with a v-src probe. The DNA sequence of 2465 nucleotides of one clone was determined. This region corresponds to the 5' protein kinase domain of v-abl plus approximately equal to 375 base pairs toward the 3' end. Four potential introns were identified. The homology between the deduced amino acid sequence of the C. elegans clone and that of the 1.2-kilobase-pair protein kinase region of v-abl is 62%. The tyrosine residue corresponding to the tyrosine that is phosphorylated in the v-src protein is conserved in the C. elegans sequence. When 95 amino acids around this tyrosine were compared with the corresponding sequences of Drosophila c-abl, v-abl, and v-src, the identities were 83%, 79%, and 56%, respectively. Hybridization of the cloned DNA with C. elegans poly(A)+ RNA revealed a major transcript of 4.4 kilobases.

Amino Acid Sequence↗
PubMed1986

Postoperative nitrous oxide analgesia. Administration from air entrainment oxygen masks with a primary flow of Entonox.

Nitrous oxide is occasionally used as an analgesic agent in the postoperative period. The feasibility of administering a known concentration from an air entrainment oxygen mask, using a primary flow of Entonox, (50% oxygen/50% nitrous oxide) was investigated. Accurox (C.R. Bard Canada Inc.) blenders, disconnected from their facemasks, were studied using a primary flow of Entonox. An increase in air entrainment of approximately 13% was demonstrated. Concentrations of about 20% nitrous oxide in oxygen enriched air, appropriate for postoperative analgesia, can be produced, but the methods are extravagant in the use of Entonox and are likely to be slightly unreliable.

Air↗
PubMed1985

Expression of a cDNA sequence encoding human purine nucleoside phosphorylase in rodent and human cells.

A cDNA sequence which contains the entire coding region for human purine nucleoside phosphorylase (PNP) was recombined for selection and expression in mammalian cells. Plasmids containing either the simian virus 40 early promoter or the mouse metallothionein promoter positioned just upstream of the PNP coding sequence were constructed. These plasmids also contained the gene for a methotrexate-resistant dihydrofolate reductase, allowing for selection and amplification of positive transferrents after transfection of cells by the DNA-calcium phosphate coprecipitation technique. Expression of human PNP activity was readily detected in both mouse (L) and CHO cells by isoelectric focusing of cell extracts followed by histochemical staining for PNP activity. The simian virus 40 early promoter directed considerable expression of human PNP activity in CHO cells but only scant activity in mouse cells. The mouse metallothionein promoter was not successful in effecting human PNP expression in CHO cells but provided substantial human PNP activity in mouse cells and was inducible by incubation with zinc. HeLa cell transferrents were isolated and screened for the presence of transferred PNP cDNA sequences by Southern hybridization analysis. RNA transcripts derived from the transferred PNP cDNA were identified in one of these cell lines.

Animals↗
PubMed1985

Concentrations of oxygen delivered by air entrainment oxygen masks.

The air entrainment devices from oxygen masks of four manufacturers (Henleys Medical Supplies Ltd, Vickers Medical, Intersurgical Ltd, C R Bard International Ltd) were studied. All were found to deliver concentrations of oxygen close to those specified. The literature is reviewed and it is suggested that provision of a total flow in excess of 60 litres/minute is most likely to provide a constant inspired oxygen concentration, whichever nominal concentration or design of mask is selected and provided distal obstruction is avoided.

Humans↗
PubMed1984

Human purine nucleoside phosphorylase cDNA sequence and genomic clone characterization.

The isolation of a cDNA clone containing the complete coding region for human purine nucleoside phosphorylase (PNP) has been described previously. In this report we present the nucleotide sequence of this cDNA clone and compare the derived amino acid sequence, encoding a protein of 32 kilodaltons, with the published amino acid composition. Using a fragment of the cDNA clone as a probe, human PNP genomic clones from a bacteriophage lambda library have been isolated and the structural organization of the wild type PNP gene determined.

Base Sequence↗
PubMed1983

Cloning of human purine-nucleoside phosphorylase cDNA sequences by complementation in Escherichia coli.

We have obtained cDNA clones that contain the entire coding region of the human purine-nucleoside phosphorylase (PNP; EC 2.4.2.1) mRNA. The cDNA sequences were generated by reverse transcription of PNP-enriched mRNA obtained by immunoadsorption of HeLa cell polyribosomes with monospecific antibody to human PNP. cDNA molecules that were close in length to PNP mRNA were separated by agarose gel electrophoresis and inserted into the Pst I site of the plasmid pBR322. Plasmid DNA from the pooled clones was used to transform PNP-deficient Escherichia coli cells, and those transformants that phenotypically expressed PNP were isolated on selective media. The presence of human PNP in the selected bacterial cells was detected by immunoprecipitation with human PNP antibody.

Base Sequence↗
PubMed1982

Drosophila mitochondrial DNA: a novel gene order.

Part of the replication origin-containing A+T-rich region of the Drosophila yakuba mtDNA molecule and segments on either side of this region have been sequenced, and the genes within them identified. The data confirm that the small and large rRNA genes lie in tandem adjacent to that side of the A+T-rich region which is replicated first, and establish that a tRNAval gene lies between the two rRNA genes and that URF1 follows the large rRNA gene. The data further establish that the genes for tRNAile, tRNAgln, tRNAf-met and URF2 lie in the order given, on the opposite side of the A+T-rich region to the rRNA genes and, except for tRNAgln, are contained in the opposite strand to the rRNA, tRNAval and URF1 genes. This is in contrast to mammalian mtDNAs where all of these genes are located on the side of the replication origin which is replicated last, within the order tRNAphe, small (12S) rRNA, tRNAval, large (16S) rRNA, tRNAleu, URF1, tRNAile, tRNAgln, tRNAf-met and URF2, and, except tRNAgln, are all contained in the same (H) strand. In D. yakuba URF1 and URF2, the triplet AGA appears to specify an amino acid, which is again different from the situation found in mammalian mtDNAs, where AGA is used only as a rare termination codon.

Amino Acid Sequence↗
PubMed1982

Nucleotide sequence of Rattus norvegicus mitochondrial DNA that includes the genes for tRNAile, tRNAgln and tRNAf-met.

The nucleotide sequence of a segment of mtDNA from Rattus norvegicus (rat) which contains the genes for tRNAile, tRNAgln and tRNAf-met has been determined. A detailed comparison has been made between this sequence and the corresponding sequences of mouse, human and bovine mtDNAs with regard to the primary and secondary structure of the tRNA genes, the regions connecting the tRNA genes, and the regions flanking the tRNA genes which code for the carboxyl terminus of URF-1 and the amino terminus of URF-2. No differences were found in the nucleotide sequences of the genes for tRNAile, tRNAgln and tRNAf-met in mtDNAs from three different female lines of rats (SASCO-1, SASCO-2 and Wild-UT) that differ by substitutions of 0.8% to 1.8% of their total nucleotides.

Animals↗
PubMed1981

Nucleotide sequence variants of Rattus norvegicus mitochondrial DNA.

The mitochondrial DNA (mtDNA) molecules of different albino, domesticated rats (Rattus norvegicus) of the SASCO colony are of two kinds (SASCO-1 and SASCO-2) in regard to their sensitivity at certain sites to a number of restriction enzymes. MtDNA molecules from Utah wild R. norvegicus (Wild-UT) have sensitivities to restriction enzymes which differ at some sites from either SASCO-1 or SASCO-2 mtDNA molecules. Four single nucleotide differences were found among the HindIII F fragments (169 nucleotides) of SASCO-1, SASCO-2, and Wild-UT mtDNAs. Arguments are presented in favor of the interpretation that each variant nucleotide is the third nucleotide of the codon containing it, and that none of the four differences would result in a difference in the respective amino acid translated.

Animals↗