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Biomedical subjects

C James

Publications and source records attributed to C James.

At least 127 records · Page 7Linked to original sources
PubMed1991

A double-blind trial of zinc supplementation in pregnancy.

A double-blind randomised trial of oral zinc supplementation was carried out during the last two trimesters of pregnancy. Fifty-six women at risk of delivering a small-for-gestational-age baby received either zinc supplement (22.5 mg daily) or placebo. Twenty-nine of the women were compliant. Zinc significantly reduced the incidence of intrauterine growth retardation, and most measured indices of labour and fetal health were better in the supplemented group. Larger studies are now needed to confirm a role for selective zinc supplementation in at-risk pregnancies.

Administration, Oral↗
PubMed1990

Measurement of protein biomass by Fourier transform infrared-photoacoustic spectroscopy.

A relatively new analytical technique, Fourier transform infrared-photoacoustic spectroscopy (FTIR-PAS), provides spectra of bacteria, fungi, and other microorganisms in solid states not suitable for conventional absorption spectroscopy. In this paper the feasibility of quantitative measurement of protein biomass on solid substrates by FTIR-PAS is examined and discussed. By measuring photoacoustic absorption bands from amide groups in the protein of microorganisms, the increase in biomass that occurs during growth was monitored directly and accurately. Incorporation of polyacrylonitrile into the sample as an internal standard was shown to be a convenient method for improving both the reliability and the range of detection by photoacoustic spectroscopy. Results of FTIR-PAS measurements of known quantities of microbial mass in simulated growth experiments suggest that the technique may be especially suitable for assays of microorganisms used in solid-state biosyntheses of drugs, hormones, and other biological agents.

Acoustics↗
PubMed1990

The eastern Cree bush-kit program evaluation; its usefulness.

In 1982 the Cree Board of Health and Social Services of James Bay in northern Quebec created the bush-kit program to provide hunters and trappers with the technical skills to handle medical problems in the bush. A formative evaluation of the program revealed a decrease in calls and in medical evacuations from the bush and high levels of satisfaction among the participants, health professionals and community leaders. However, specific service accessibility problems were identified at the time of the evaluation as indicated by participation rates of only 50% of the targeted hunters and trappers. These findings as well as discussions with bush-kit administrators led to subsequent improvements in the program and an increased participation rate the following year.

Community Health Workers↗
PubMed1990

Training perception of acute airflow obstruction.

Ten asthmatics selected for their tendency to experience frequent acute exacerbations were instructed in peak flow measurement. Each subject then recorded estimated peak flow (EPF) and measured peak flow (PF) at home twice daily. Data for up to 56 consecutive observations (4 weeks) per subject were analyzed. The correlation coefficient between EPF and PF following PF drops of 15% was .993 overall and was not significantly different following PF drops even greater than 25%. The absolute and proportional differences between PF and EPF were also not significantly affected by the magnitude of PF drop but decreased over time indicating improved accuracy of estimates with practice. Asthmatics can be trained to estimate accurately acute drops in airflow. Such ability has not been demonstrated in prior studies which utilized verbal symptom reports as indicators of subjective perception of airflow. Accurate perception would be a useful aid in achieving early recognition of acute exacerbations and in improving medication compliance. It is an adjunct to regular peak flow measurement, not a substitute for it.

Airway Obstruction↗
PubMed1989

Antimyosin imaging in acute transmural myocardial infarctions: results of a multicenter clinical trial.

Murine monoclonal antimyosin antibody has been shown experimentally to bind selectively to irreversibly damaged myocytes. To evaluate the safety and efficacy of monoclonal antimyosin for identifying acute transmural infarction, 50 patients with acute Q wave myocardial infarction were entered into a phase I/II multicenter trial involving three clinical sites. Indium-111 antimyosin was prepared from an instant kit formulation containing 0.5 mg of diethylene triamine pentaacetic acid (DTPA)-coupled Fab fragment (R11D10) and 1.2 to 2.4 mCi of indium-111. Average labeling efficiency was 92%. Antimyosin was injected 27 +/- 16 h after the onset of chest pain. Planar or tomographic imaging was performed 27 +/- 9 h after injection in all patients, and repeat imaging was done 24 h later in 39 patients. Of the 50 patients entered, 46 showed myocardial uptake of antimyosin (sensitivity 92%). Thirty-one of 39 planar scans performed at 24 h were diagnostic; 8 showed persistent blood pool activity that cleared by 48 h. Focal myocardial uptake of antimyosin corresponded to electrocardiographic infarct localization. No patient had an adverse reaction to antimyosin. In addition, 125 serum samples, including 21 collected greater than 42 days after injection, were tested for human antimouse antibodies, and all samples were assessed as having undetectable titers. Intensity of antimyosin uptake was correlated with infarct location and the presence or absence of collateral vessels. There was a significant correlation between faint uptake and inferoposterior infarct location. In 21 patients who had coronary angiography close to the time of antimyosin injection, there was a significant correlation between faint tracer uptake and closed infarct-related vessel with absent collateral flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

The identification, molecular cloning and characterisation of a gene from Phanerochaete chrysosporium that shows strong homology to the exo-cellobiohydrolase I gene from Trichoderma reesei.

We have identified a genomic DNA fragment from the lignin-degrading fungus Phanerochaete chrysosporium (P.c.) that hybridizes to a DNA probe encoding part of the exo-cellobiohydrolase I (CBHI) gene of Trichoderma reesei (T.r.). This fragment has been subcloned and its nucleotide sequence determined. We demonstrate that it could encode a 516 residue protein that shows strong homology with the known protein sequence of CBHI from T.r. Comparison of the two nucleotide sequences identifies two regions within the P.c. sequence that are not represented in T.r. Further inspection of these regions reveals sequences closely related to the conserved elements of filamentous fungal introns. We conclude that the P.c. genomic sequence contains the same number of introns (2) as found in T.r. but that these are located at different relative positions within the two genes. The transcript from the P.c. sequence is induced in the presence of cellulose but not by glucose and we therefore conclude that this sequence represents the first cellulase gene to have been described from this organism.

Amino Acid Sequence↗
PubMed1987

PAF binding sites. Characterization by [3H]52770 RP, a pyrrolo[1,2-c]thiazole derivative, in rabbit platelets.

52770 RP, the N-(3-chlorophenyl)-3-(3-pyridinyl)-1H,3H-pyrrolo[1,2-c]thiazole -7-carboxamide, displaces in a potent, specific and competitive manner [3H]PAF from its binding sites on rabbit platelets. Since 52770 RP is not structurally related to PAF and has low liposolubility with respect to PAF, it was selected as a potential radioligand for PAF receptor sites. [3H]52770 RP displayed high-affinity, specificity, as well as saturable and displaceable binding to a single class of recognition sites in intact platelets and crude platelet membranes. In these preparations, the values of binding parameters were, respectively, 8.5 and 7.6 nM for Kd, 0.2 pmol/5 X 10(7) platelets and 3.66 pmol/mg protein for Bmax and 0.96 and 0.91 for nH. Inasmuch as the (+)-52770 RP was 300-fold more potent than the (-)-isomer at displacing [3H]52770 RP in intact platelets, the studied binding site manifested stereospecific discrimination. A variety of pharmacological agents including pro- and anti-aggregant compounds did not exhibit affinity for [3H]52770 RP binding sites. In contrast, PAF, some of its active analogues and several recognized PAF antagonists (BN 52021, brotizolam, L-652,731, triazolam), displaced the [3H]52770 RP binding. Studies carried out using [3H]PAF demonstrated that 52770 RP was approximately 4- and 200-fold more potent than L-652,731 and BN 52021 respectively, as a PAF-receptor antagonist. In washed rabbit platelets, the rank order of potency (Ki) for several analogues of 52770 RP, to displace [3H]PAF from its binding sites, was highly correlated (r = 0.96) to their ability to antagonize [3H]52770 RP binding. In functional studies, 52770 RP antagonized not only the PAF-induced aggregation in washed rabbit platelets but also the hypotension evoked by PAF in the anesthetized rat. In this respect, it was 26 and 2 times more potent than L-652,731, respectively. In conclusion, [3H]52770 RP might represent a novel interesting tool for furthering our understanding of the role of PAF binding sites in pathophysiological processes.

Animals↗
PubMed1987

Induction of integrated adenovirus E1A and E1B genes in transformed human cells by phorbol ester tumor promoters.

The effect of phorbol esters on transcription of human type 5 adenovirus (Ad5) early region 1 (E1) genes was studied in two human cell lines (293 and KB16) that contain integrated viral DNA. In 293 cells 12-O-tetradecanoylphorbol-13-acetate (TPA), phorbol 12,13-dibutyrate and phorbol 12,13-didecanoate caused a 2- to 3-fold increase in cytoplasmic levels of E1 RNA within 90 min, whereas the nonpromoting TPA analogues 4-alpha-phorbol 12,13-didecanoate and phorbol, or the addition of serum to serum-starved cells, had no effect on E1 RNA. Stimulation by TPA was transient, and the concentrations of all E1 RNA species returned to basal levels by 5 h. The kinetics of E1 RNA accumulation in the presence of TPA were unaffected by cycloheximide, although levels of E1 RNA remained elevated in these conditions. The apparent molecular sizes of major RNA species synthesized from the E1A and E1B regions in 293 cells were the same as those seen early in productive infection by Ad5, and were not changed after induction by TPA. Nuclear run-on assays showed that E1 transcription, as well as transcription of c-fos, c-myc, and beta-actin was stimulated in 293 cells within 30 min of TPA exposure and returned to basal levels by 60 min. In contrast to the 293 cells, expression of Ad5 E1 genes in a second transformed human cell line, KB16, was not altered by TPA. These results show that the induction of Ad5 E1 genes by TPA does not require their presence on infecting genomes, but suggest that inducibility of integrated, functionally expressed E1 genes can be influenced by factors other than their primary sequence.

Adenovirus Early Proteins↗
PubMed1987

Synthesis and antisecretory and antiulcer activities of derivatives and analogues of 2-(2-pyridyl)tetrahydrothiophene-2-carbothioamide.

New thioamide derivatives of 2-(2-pyridyl)tetrahydrothiophene-2-carbothioamide (29) and related compounds (in which the tetrahydrothiophene ring was replaced by tetrahydrothiopyran, tetrahydrofuran, 1,3-dithiane, or 1,3-oxathiane and where the pyridine ring was replaced by other nitrogen heterocycles) were synthesized and tested for their antisecretory and antiulcer activities. These thioamides were prepared according to one of the following methods: reaction of an isothiocyanate with the carbanion of the corresponding cyclic precursor (for secondary thioamides); reaction of ammonia or an amine with the dithio ester prepared from the same precursor (for primary, secondary, and tertiary thioamides). These thioamides were evaluated by the Shay method to measure their antisecretory activity and by the stress-induced-ulcer method to test their antiulcer activity. Structure-activity relationships are discussed. N-Methyl-2-(2-pyridyl)tetrahydrothiophene-2-carbothioamide (R.P. 40749, 30) exhibited activities that were at least 10 times higher than those reported for cimetidine.

Animals↗