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Biomedical subjects

J R Edwards

Publications and source records attributed to J R Edwards.

At least 91 records · Page 5Linked to original sources
PubMed1990

The psychometric properties of the Bortner Type A Scale.

Recent evidence indicates that the relationship between Type A behaviour pattern (TABP) and coronary heart disease (CHD) is dependent upon the method of measuring TABP. This suggests that the psychometric properties of TABP measures should be carefully investigated. This article examines one widely used TABP measure, the Bortner Scale, using data from 1320 working adults divided into three random samples. The reliability of the Bortner Scale as an overall TABP index is unacceptably low. However, further analyses indicate that, rather than reflecting a single dimension, the Bortner Scale contains two independent dimensions, one reflecting speed and the other reflecting competitiveness. The speed dimension was negatively related to job satisfaction and, to a lesser extent, positively related to anxiety and somatic symptoms, whereas the competitiveness dimension was positively related to job satisfaction. Implications for the use of the Bortner Scale are discussed.

Adult↗
PubMed1989

Polymerase chain reaction compared with concurrent viral cultures for rapid identification of human immunodeficiency virus infection among high-risk infants and children.

To determine the usefulness of DNA amplification by polymerase chain reaction for the early identification of human immunodeficiency virus type 1 (HIV-1) infection in infants and children, we compared the polymerase chain reaction and concurrent viral cultures of peripheral blood mononuclear cells from 25 high-risk subjects aged 5 weeks to 8 years. In two separate primer pairs, HIV-1 proviral DNA gag sequences were successfully identified in cell lysates from seven patients, including two infants with previously indeterminate HIV-1 status on the basis of serologic and culture results. In the remaining 18 patients the polymerase chain reaction was negative for HIV-1. Simultaneously grown HIV-1 cultures concurred with polymerase chain reaction results for all patients. In an 18-month-old infant who had had a single HIV-1 positive culture at 1 month of age with four subsequent negative cultures, both polymerase chain reaction and HIV-1 culture were negative. Our data demonstrate the clinical applicability of polymerase chain reaction on crude cell lysates for the rapid, early, definitive detection of HIV-1 infection in high-risk infants and children.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Therapeutic activity of meropenem in experimental infections.

Meropenem and comparative antibiotics were evaluated in five models of infection. All antibiotics were administered parenterally; imipenem was used in combination with cilastatin but meropenem and other agents were given alone. Generalized infections in mice caused by Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, Serratia marcescens, Proteus mirabilis or Pseudomonas aeruginosa all responded to low doses of meropenem or imipenem. Immunocompromised mice infected with Ps. aeruginosa responded to slightly higher doses of meropenem or gentamicin but required four to seven times the dose of other agents. Those given a greater challenge of Ps. aeruginosa were treated most successfully by meropenem. Treatment with meropenem, imipenem or ceftazidime caused significant reductions of E. coli in the urinary bladder and kidneys of mice challenged per urethram. Infection with Ps. (Xanthomonas) maltophilia localized to the subcutaneous neck tissue of guinea pigs was also treated successfully. Lung infections caused by Ps. aeruginosa in guinea pigs were treated effectively by meropenem, imipenem, and ceftazidime at the dose of 10 mg/kg but only meropenem eradicated bacteria from all the tissues examined. These results demonstrate that meropenem has excellent antibacterial activity in vivo in both normal and immunocompromised animals and in some models of infection is superior to imipenem.

Animals↗
PubMed1989

In vitro antibacterial activity of SM-7338, a carbapenem antibiotic with stability to dehydropeptidase I.

SM-7338, a new carbapenem antibiotic, was demonstrated to have potent antibacterial activity against a broad spectrum of aerobes, including Staphylococcus aureus, beta-hemolytic streptococci, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria spp., members of the family Enterobacteriaceae, Pseudomonas spp., and gram-positive and gram-negative anaerobes in a collection of 1,102 unselected clinical isolates. At a concentration of 0.5 micrograms/ml, SM-7338 inhibited 90% of these strains. The spectrum of activity of ceftazidime and cefotaxime was more limited, and many of the Enterobacteriaceae and Pseudomonas spp. were resistant to these agents, piperacillin, or gentamicin. A collection of ofloxacin-resistant strains was inhibited by SM-7338 or imipenem at 4 micrograms/ml. SM-7338 was more active than metronidazole and clindamycin against anaerobes. Of the carbapenems, imipenem had greater activity against staphylococci but SM-7338 was much more active against Haemophilus, Branhamella, and Neisseria spp. and all genera of Enterobacteriaceae tested. The MIC of SM-7338 for 90% of these strains ranged from less than or equal to 0.008 to 0.13 micrograms/ml. When tested against 124 strains of Pseudomonas aeruginosa, SM-7338 inhibited 76% at 0.5 microgram/ml but imipenem inhibited only 15% at this concentration. Both carbapenems exhibited similar activities against Bacteroides spp., but SM-7338 was more active than imipenem against Clostridium spp. The MBC of SM-7338 was most commonly the same as or twice the MIC. SM-7338 and imipenem showed excellent activities against bacteria elaborating chromosome- or plasmid-mediated beta-lactamases, including those conferring resistance to broad-spectrum cephalosporins. The activity of SM-7338 was generally unaffected by the culture medium used, pH, 25% human serum, and inoculum size, but the susceptibility of Xanthomonas maltophilia was medium dependent.

Bacteria↗
PubMed1989

Hematologic disorders affecting the lungs.

Pulmonary involvement by hematologic disorders can occur through any number of mechanisms involving abnormalities of the fluid phase of hemostasis, quantitative or qualitative defects in the cellular components, and direct and indirect involvement of the malignancies derived from the hematopoietic system. Consideration of possible mechanisms through which the blood can alter pulmonary physiology and result in recognizable disorders, such as pulmonary hemorrhage, thromboembolism, fibrosis, or obstruction, can lead to more rapid and appropriate diagnosis. Further work aimed at diagnosis and management of hematologic disorders, prior to the development of pulmonary manifestations, will enable us to prevent the long-term sequelae. Intervention aimed at relieving the acute pulmonary symptoms followed by long-term management of the hematologic disease can result in significantly improved prognosis and quality of life for our patients who have manifested pulmonary symptoms secondary to a hematologic disease.

Anemia, Sickle Cell↗
PubMed1988

The impacts of positive psychological states on physical health: a review and theoretical framework.

While much research has focused on the impacts of negative psychological states, such as stress, on physical health, relatively little research has examined the effects of positive psychological states. We suggest this imbalance is attributable to inadequate theoretical and methodological development regarding the impacts of positive psychological states on health. This paper presents a framework by which positive psychological states may influence physical health. Following this, we review evidence pertaining to this framework. We conclude by discussing methodological issues associated with this relatively new area of inquiry.

Adaptation, Psychological↗
PubMed1988

Inherited progressive spinal myelinopathy in Murray Grey cattle.

In a breeding experiment conducted to determine the mode of inheritance of progressive spinal myelinopathy, semen from a Murray Grey bull which had previously sired affected calves was used to inseminate 120 cows. Female progeny were then inseminated with semen from the same bull. Of the 51 calves born, six (11.8%) had spinal cord lesions consistent with progressive spinal myelinopathy. From analysis of pedigrees and the results of the breeding experiment it was concluded that the condition was inherited as an autosomal recessive condition in Murray Grey cattle.

Animals↗
PubMed1988

Cefotetan: antibacterial activity against Staphylococcus aureus in the presence of human serum.

Cefotetan is a broad spectrum cephamycin antibiotic with a long serum half-life (3-4.5 h): this is explained, in part, by serum-protein-binding (SPB) of 88%. The rate of kill of Staphylococcus aureus by cefotetan was assessed in human serum or broth containing reducing concentrations of drug simulating those seen following a 1 g intravenous dose to man. Cefotetan was bactericidal in serum despite the assumed concentration of unbound drug never reaching the minimum inhibitory concentration (MIC) for the test strain. In a separate study, ceftriaxone (SPB 96%) was more active in broth (MIC 4 mg/1) than cefotetan (MIC 16 mg/1). In 100% serum the minimum bactericidal concentration (MBC) of ceftriaxone was 64 mg/1 whilst the MBC for cefotetan was 16 mg/1.

Blood Proteins↗
PubMed1988

Worldwide assessment of the activity of cefotetan against clinical isolates.

Data on the antibacterial activity of cefotetan collected since 1985 have been compiled into a computer database and an analysis of results on more than 100,000 clinical isolates presented. The studies were conducted in 285 hospitals located throughout Europe, South Africa, Australia and the USA. The results demonstrate the effectiveness of cefotetan as a broad spectrum agent with significant activity against clinically important aerobes and anaerobes. This is exemplified by the susceptibility to cefotetan of 92% of 14,315 strains of Staphylococcus aureus, 99% of 24,103 strains of Escherichia coli and 93% of 1,841 strains of Bacteroides fragilis.

Cefotetan↗
PubMed1986

Structural elucidation of a water-insoluble glucan produced by a cariogenic oral Streptococcus.

The structure of a water-insoluble polysaccharide produced by the D-glucosyl-transferase of Streptococcus mutans 6715 has been elucidated through periodate oxidation, Smith degradation, dextranase digestion, concanavalin A binding studies, and methylation combined with g.l.c.-m.s. analysis. These studies show that the D-glucan is comprised of 67% alpha-(1----3) linkages in a contiguous backbone with the remaining 33% as alpha-(1----6) linkages, possibly as linear residues extending from alpha-(1----6) branch points. Of the residues, 14% are branch points and the ratio of linear alpha-(1----3) residues in the backbone to alpha-(1----6) residues in the side chain was found to be 5:2. Dextranase digestion and Smith degradation both gave rise to a high-molecular-weight fraction that is only alpha-(1----3) linked.

Carbohydrate Conformation↗
PubMed1986

Survey of anthelmintic resistance in Western Australian sheep flocks. 1. Prevalence.

Between July 1981 and December 1983, 116 randomly selected sheep farms in the south west of Western Australian were surveyed for resistance to anthelmintics. A faecal worm egg count reduction test was carried out on each farm. Anthelmintics tested were thiabendazole (44 mg/kg) and levamisole (7.5 mg/kg) given by intra-ruminal injection and comparisons were made with an untreated group on each farm. Successful tests were carried out on 84 farms and 68% of these had resistant worms present. The prevalence of thiabendazole resistant populations was for H. contortus 18%; Teladorsagia, 41% and Trichostrongylus, 48% and for levamisole resistant populations H. contortus, 10%; Teladorsagia, 41%; Trichostrongylus, 24%, and Nematodirus, 10%. Multiple resistant populations were found on 17% of farms. Although the distribution of nematode genera varied between the 400 to 750 mm and the greater than 750 mm rainfall zones there was no significant difference in the prevalence of resistance between zones. About one third of resistant populations were severely resistant (less than 60% reduction). It is likely that resistant worms were present on many farms without causing clinical disease and continued anthelmintic selection pressure will result in further development of resistance.

Animals↗
PubMed1986

Survey of anthelmintic resistance in Western Australian sheep flocks. 2. Relationship with sheep management and parasite control practices.

Owners of 116 farms, whose flocks had been tested for anthelmintic resistance, were interviewed to determine their use of various sheep management and parasite control practices and their knowledge and adoption of recommended procedures for the prevention and control of resistance. Farmers knowledge of current recommendations related mainly to changing drenches and drench groups. Other aspects of the recommended program including reduction of drenching frequency and the use of alternative management strategies were not considered as important by farmers. For most questions a high proportion of farmers (greater than 20%) had no opinion. Associations between various strategies for nematode control and resistance of Trichostrongylus and Teladorsagia to thiabendazole and levamisole were examined. These relationships differed between anthelmintics and nematode genera. A number of factors were related to resistance of one or both nematode genera to one or both anthelmintic groups. These factors included flock size, percentage of ewes in the flock, cattle number, main sheep production activity, grazing strategy, frequency of drenching, changes in the frequency of drenching, number of summer drenches and the method of estimating dose rates. It was concluded that the methods employed to control anthelmintic resistance may vary with the nematode, its resistance status and the anthelmintic to which it is exposed. Modifications to the previously recommended program have been proposed which incorporate selection of the anthelmintic to be used following a test for anthelmintic resistance.

Animal Husbandry↗