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Biomedical subjects

R Lowe

Publications and source records attributed to R Lowe.

At least 19 recordsLinked to original sources
PubMed1996

Molecular cloning of an avian anti-Müllerian hormone homologue.

Anti-Müllerian hormone (AMH) is responsible for regression of the Müllerian ducts in males during embryonic development. This peptide hormone of the transforming growth factor-beta family is also believed to play a broader role in sex determination, affecting differentiation and morphogenesis of the testes. Accordingly, in mammals, AMH is produced at much higher levels in male fetuses than in female fetuses. In contrast, in birds, both male and female embryonic gonads produce AMH at high levels, although in males it is still responsible for regression of the Müllerian ducts. Its persistent expression by the embryonic ovaries and its role in female sex determination in birds is not understood. We have cloned an avian homologue to AMH. Avian AMH cDNA encodes a 644 amino acid protein that is 42% identical to human AMH overall with increased identity at the carboxyl terminus. Similarities to human AMH include motifs of sequence identity, a conserved putative plasmin cleavage site and cysteine alignments, and similar genomic intron/exon structure. Antibodies to recombinant avian AMH cross-react with recombinant human AMH and were used to show that avian AMH is glycosylated as has been shown for the human form. The avian AMH gene is transcribed in both male and female gonads but not in liver, heart, kidney or muscle.

Amino Acid Sequence↗
PubMed1996

Occupational health nurses and occupational hygiene: a study of South African nurses' attitudes.

The objectives of this study were to assess the current occupational hygiene practices of occupational health nurses and to assess their attitudes to the identification and initial quantification of workplace hazards. A questionnaire was mailed to all occupational health nurses registered with the South African Society of Occupational Health Nurses. Responses were obtained from 221 (53.7%). Responders and non-responders did not differ on key characteristics. Only 14 (6%) of the respondents performed occupational hygiene tasks as part of their routine work and only 31 (14%) volunteered hazard identification and quantification as tasks that would significantly improve practice. Nevertheless, when asked directly, 120 (54%) agreed that occupational hygiene fell into the ambit of occupational health nursing. Over 70% were positive about receiving theoretical and practical hygiene training. Constraints to greater hazard identification included limited time and resources and concern about intruding into the domains of other practitioners. Sufficient numbers of occupational health nurses were interested in identifying hazards in the workplace for training courses to be planned and offered now; however, restraints to practice need to be clarified and removed for these new skills to be used effectively.

Attitude of Health Personnel↗
PubMed1995

Traumatic spinal cord injury and psychological impact: a cross-sectional analysis of coping strategies.

Many studies have suggested a relationship between coping strategies used to deal with stressors and levels of psychological well-being. To explore this further the current study examined such relationships in people who have sustained a spinal cord injury. Measures of psychological impact and coping strategies were taken from those in their sixth week post-injury (N = 41) and those between four and seven years post-injury (N = 30). The results were analysed using stepwise multiple regression. This provided a number of models containing coping strategies that accounted for a certain proportion of the variance in each of the psychological impact variables. While the results help to identify specific coping strategies associated with better adjustment, they also highlight the need to adopt a longitudinal approach in the investigation of psychological responses to spinal cord injury.

Activities of Daily Living↗
PubMed1994

Tumors expressing the cytosine deaminase suicide gene can be eliminated in vivo with 5-fluorocytosine and induce protective immunity to wild type tumor.

Successful expression of the cytosine deaminase (CD) suicide gene in vivo is demonstrated in three weakly immunogenic murine tumor models: the 102 and 205 fibrosarcomas and the 38 adenocarcinoma. Normal mammalian cells do not contain cytosine deaminase, but tumor cells transduced with retroviral vectors containing the CD gene metabolize the relatively nontoxic prodrug 5-fluorocytosine to the highly toxic 5-fluorouracil. In vitro cells expressing the CD gene are killed by 5-fluorocytosine while unmodified cells are not. When injected into syngeneic mice, CD+ tumors can also be eliminated in vivo by systemic treatment with 5-fluorocytosine without significant toxicity to the host. Animals whose CD+ tumors were eliminated with prodrug treatment resist subsequent rechallenge with unmodified wild type tumor. This posttreatment immunity appears to be tumor specific. Applications of the CD system in gene therapy models are discussed.

Animals↗
PubMed1994

Swapping over roles.

Explore the source record for details and available documents.

Adaptation, Psychological↗
PubMed1993

[10 years of nosocomial infections at the Santo Tomás Hospital].

The incidence of nosocomial urinary tract infections (UTI) in the medical services of Santo Tomás Hospital from 1980 to 1985 was 56% in Neurology Section, 73% in cardiology and 74% in nephrology. These percentages declined, with epidemiological surveillance, to 21%, 31% and 53% respectively, for the period between 1986 and 1990. In the surgical services the incidence of nosocomial UTI was 85% in urology and 15% in general surgery, from 1980 to 1985. The incidence remained unchanged in urology (81%) and general surgery (17%) despite epidemiological surveillance, but decreased in neurosurgery (from 55% to 37%) for the period between 1986 and 1990. Between 1985 and 1990, Staphyloccocus aureus was the most frequently isolated bacterium from surgical wounds (34%) and from patients with intravenous catheters (23%). Pseudomonas aeruginosa was the most frequently isolated bacterium in nosocomial UTI (26%) and respiratory tract infections (45%) and in patients with nosocomial septicemia, it was a species of Klebsiella.

Cross Infection↗
PubMed1992

The proposed death certificate for South Africa. Part I. Death certificate description.

An altered 'Cause of Death' certificate is proposed. The major changes involve the use of the international format for certification of death and provision for collection of extra data, i.e. estimated age at death, sex, population group and, where relevant, the mass of an infant at birth. The new format will facilitate improved data collection and the certificate will stand international comparison.

Data Collection↗
PubMed1992

The proposed death certificate for South Africa. Part II. Feasibility study.

The proposed new death certificate was tested in urban and rural hospitals and among general practitioners. Of the 471 death certificates returned, 70% were correctly completed. The underlying cause of death was identifiable in 86.6% of cases. The accuracy of cause of death statements was analysed in greater detail. Some items on the proposed form were not clear and needed improvement, i.e. instructions to mark an applicable answer and refer to instructions on the reverse page. The participants completed a questionnaire to assess and comment on the new form. A refined version thereof was prepared as a result of this study.

Cause of Death↗
PubMed1992

Comparative efficacy of contact lens disinfection solutions.

Using the D value method of analysis, we evaluated the relative antimicrobial effectiveness of eight contact lens disinfection solutions against a standard population of challenge organisms as defined in the Microbiological Guidelines proposed by the Food and Drug Administration (FDA). Six bacteria (Escherichia coli, Staphylococcus aureus, S. epidermidis, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Serratia marcescens) and two fungi (Aspergillus fumigatus, Candida albicans) were investigated. The disinfectants included hydrogen peroxide (AOSept, MiraSept, Oxysept), chlorine-based solutions (Aerotab and Softab), soaking solutions containing synthetic, high molecular weight preservatives (ReNu and Opti-Free) and a thimerosal preserved soaking solution (Hydrocare Cleaning and Soaking Solution). The one-step hydrogen peroxide system (AOSept) was evaluated both with and without the catalytic disk. To facilitate comparison of the disinfecting solutions, we defined a new measure of performance, namely "power" of solution. This has an advantage over the "safety factor" because the solution power is independent of the size of the initial inoculum. Because different approaches to analysis may yield a wide range of D values for one set of survival data we call for adoption of a standardized approach. Our results suggest that one of the chlorine-based solutions fails to meet the FDA recommendations for bacterial challenge. Most solutions performed poorly against mycotic challenge. However, when used over longer disinfecting periods, 3% hydrogen peroxide and the Hydrocare solution gave adequate performance against fungi.

Bacteria↗
PubMed1991

Case report: systemic lupus erythematosus (SLE) serositis mimicking acute cholecystitis.

Systemic lupus erythematosus (SLE) is a well recognized cause of an acute abdomen. What is less well recognized is that the underlying pathology can be varied. The computed tomography (CT) and ultrasound appearances of the gall-bladder in a case of SLE serositis are shown. The imaging findings were strongly suggestive of primary gall-bladder disease although at laparotomy the gall-bladder showed serosal inflammation only.

Acute Disease↗
PubMed1991

Effect of hydrogel lens wear on tear film stability.

Noninvasive break-up time (NIBUT) of the tears was measured in a controlled, randomized, double-masked study to assess: (1) the stability of the prelens tear film during wear of new high and low water content lenses and (2) the stability of the precorneal tear film following lens removal after 1 h of wear. The prelens tear film NIBUT of 6 subjects was found to be relatively constant over a 1-h wearing period, averaging 6.1 +/- 1.1 s (mean +/- SEM). These values were significantly (Scheffe's S test, p less than 0.05) lower than those recorded for the precorneal tear film before lens insertion (33.5 +/- 10.6; mean +/- SEM), although 85% of prelens tear film NIBUT's were greater than the 3-s average interblink period reported previously for soft lens wearers. After lens removal, precorneal tear film NIBUT was reduced significantly compared to prewear levels (Scheffe's S test, p less than 0.05) for up to 15 min. Application of the monomolecular growth model to the NIBUT recovery data revealed a half-time for recovery of 6.0 min, with recovery 95% complete 25.8 min after lens removal. Lens type was not a significant factor in tear film stability, either during wear or after lens removal. The basis for reduced precorneal tear film NIBUT after lens removal is unknown; however, a disruption of the mucin layer coating the corneal epithelium is the most likely mechanism. Indeed, the technique of measuring precorneal tear film NIBUT after lens removal may be a useful determinant of the extent to which contact lens wear disrupts the precorneal mucin layer, providing an indication of the susceptibility of the cornea to a variety of complications.

Blinking↗