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Biomedical subjects

D Bourne

Publications and source records attributed to D Bourne.

At least 19 recordsLinked to original sources
PubMed2002

West Nile virus in livestock and wildlife.

WN virus is one of the most ubiquitous arboviruses occurring over a broad geographical range and in a wide diversity of vertebrate host and vector species. The virus appears to be maintained in endemic foci on the African continent and is transported annually to temperate climates to the north in Europe and to the south in South Africa. Reports of clinical disease due to natural WN virus infection in wild or domestic animals were much less common than reports of infection (virus isolation or antibody detection). Until recently, records of morbidity and mortality in wild birds were confined to a small number of cases and infections causing encephalitis, sometimes fatal, in horses were reported infrequently. In the period 1996-2001, there was an increase in outbreaks of illness due to WN virus in animals as well as humans. Within the traditional range of WN virus, encephalitis was reported in horses in Italy in 1998 and in France in 2000. The first report of disease and deaths caused by WN virus infection in domestic birds was reported in Israel in 1997-1999, involving hundreds of young geese. In 1999 WN virus reached North America and caused an outbreak of encephalitis in humans in the New York area at the same time as a number of cases of equine encephalitis and deaths in American crows and a variety of other bird species, both North American natives and exotics. Multi-state surveillance for WN virus has been in place since April 2000 and has resulted in the detection of WN virus in thousands of dead birds from an increasing number of species in North America, and also in several species of mammals. The surveillance system that has developed in North America because of the utility of testing dead birds for the rapid detection of WN virus presence has been a unique integration of public health and wildlife health agencies. It has been suggested that the recent upsurge in clinical WN virus infection in wild and domestic animals as well as in humans may be related to the emergence of one or more new strains of WN virus. Virus isolated in New York in 1999 was found to be identical to that from Israel. It was alarming for WN virus to so easily invade the United States and surprising that it became established so quickly in the temperature climate of New York. Its persistence and rapid expansion in the United States leave a number of unanswered questions. New disease characteristics and patterns have occurred and more are evolving as WN virus further invades the western hemisphere. Additional animal research is needed to answer these questions. Some of the research needs include bird migration as a mechanism of virus dispersal, vector and vertebrate host relationships, virus persistence mechanisms, laboratory diagnosis, viral pathogenesis, risk factor studies, vaccine development, and WN virus impact on wildlife (CDC 2001a). Determination of the primary reservoir host species that are involved in the epidemiology of WN virus and the suitable sentinel species for active surveillance are also important research areas.

Amphibians↗
PubMed2001

Flavor threshold for acetaldehyde in milk, chocolate milk, and spring water using solid phase microextraction gas chromatography for quantification.

The detection threshold of acetaldehyde was determined on whole, lowfat, and nonfat milks, chocolate-flavored milk, and spring water. Knowledge of the acetaldehyde threshold is important because acetaldehyde forms in milk during storage as a result of light oxidation. It is also a degradation product of poly(ethylene terephthalate) during melt processing, a relatively new packaging choice for milk and water. There was no significant difference in the acetaldehyde threshold in milk of various fat contents, with thresholds ranging from 3939 to 4040 ppb. Chocolate-flavored milk and spring water showed thresholds of 10048 and 167 ppb, respectively, which compares favorably with previous studies. Solid phase microextraction (SPME) was verified as an effective method for the recovery of acetaldehyde in all media with detection levels as low as 200 and 20 ppb in milk and water, respectively, when using a polydimethyl siloxane/Carboxen SPME fiber in static headspace at 45 degrees C for 15 min.

Acetaldehyde↗
PubMed1999

A retrospective cohort study of post mastectomy pain syndrome.

Post mastectomy pain syndrome is a condition which can occur following breast surgery and has until recently been regarded as uncommon. Recent reports have suggested that it may affect 20% or more of women following mastectomy. The symptoms are distressing and may be difficult to treat however treatment for neuropathic pain can be successful. This paper reports a retrospective cohort of consecutive mastectomy cases over a six year period in one region of whom 511 survivors were traced and eligible for survey. A total of 408 completed a questionnaire survey which revealed that 175 (43%) had ever suffered from postmastectomy pain syndrome and 119 (29%) reported current symptoms although the majority were decreasing in intensity. A striking finding was the very high cumulative prevalence in younger women (65%) decreasing to 26% in the over 70 year group. The details of the onset, frequency and intensity of symptoms are described along with their natural history. The age effect on the frequency of the syndrome influences the marital status, employment status, housing, and educational status of those who report typical symptoms. Body weight and height are also associated with the frequency of post mastectomy pain syndrome. Relationship between the frequency of post mastectomy pain syndrome and radiotherapy, chemotherapy and the use of tamoxifen are difficult to unravel because of the combinations of pre and post operative treatments received confounded by age. The implications of a much higher frequency of post mastectomy pain are discussed with regard to management and counselling. The high frequency of the syndrome in the younger women is important and possible explanations are explored.

Adult↗
PubMed1996

Surveillance for equity in cervical cytology screening.

BACKGROUND: The opportunistic basis on which screening has been conducted in South Africa has resulted in multiple rescreening of a small proportion of the population (which excludes most women at high risk) and low population coverage. There has consequently been a failure of screening to impact on the incidence of cervical cancer in most of the population. AIM: To propose the use of the ratio of smears showing cervical intra-epithelial neoplasia (CIN)III: smears showing signs of malignancy as an indicator for the surveillance of equity in cervical cytology screening, and to apply this indicator to an area of the Western Cape of South Africa. RESULTS: Marked inequity in screening is demonstrated between metropolitan and non-metropolitan area, and between different non-metropolitan districts. Inequity in screening between different age groups of women is also found, and this is associated with an inappropriately young age distribution of screening activity. CONCLUSIONS: The application of this indicator in the routine surveillance of screening activity may be useful in monitoring progress towards the implementation of more equitable screening programmes, and the validity of the indicator should be tested in other settings.

Adolescent↗
PubMed1996

Trends in cervical cancer mortality in South Africa.

BACKGROUND: Cervical cancer is an important cause of death throughout the world, especially in less developed countries. Reports of trends in cervical cancer mortality from less developed countries have been limited by poor data quality and inaccurate population estimates. This paper examines trends in cervical cancer mortality in South Africa from 1949 to 1990 and discusses the impact of cytology screening on these trends. METHODS: Analysis of national mortality statistics and reconstructed population data. RESULTS: The age-standardized mortality rates for Whites declined after the mid 1960s, while that for Coloureds rose, particularly before the 1970s. These trends were affected predominantly by trends among women in the 35-64 age range. CONCLUSIONS: The pattern of mortality in successive birth cohorts for Whites is consistent with a reduction in age-specific mortality following the advent of cytological screening. The same pattern is not evident in trends for Coloureds, among whom screening has apparently had a minor impact if any at all. The apparent lack of impact of screening in those groups of women most at risk of cervical cancer lends weight to demands for the implementation of equitable and rational screening programmes for cervical cancer in South Africa and internationally.

Adult↗
PubMed1996

Ouabain production by cultured adrenal cells.

The adrenal cortex releases a sodium pump inhibitor. The present studies tested whether this material was endogenous and identical to ouabain by 1) studying the production of ouabain in long term cultures of adrenocortical cells, 2) seeking evidence that ouabain might be taken up from exogenous sources by adrenocortical cells, 3) examining the release of adrenocortical cells loaded with exogenous ouabain, 4) attempting to stimulate ouabain steroidogenesis in cultured adrenocortical cells, and 5) performing further chemical analysis on ouabain immunoreactivity released by cultured adrenocortical cells. Our results indicate that ouabain immunoreactivity is present in conditioned medium from both murine Y-1 adrenocortical cultures and primary bovine adrenocortical cell (BAC) cultures. We also found that BACs bind and internalize [3H]ouabain. Bound [3H]ouabain is released from BACs by both receptor dissociation and cytoplasmic release of internalized [3H]ouabain. Only one isoform of membrane sodium, potassium-adenosine triphosphatase, alpha 1, was expressed in the adrenal. Authentic ouabain was not metabolized during membrane binding or while present intracellularly. Stimulation of steroidogenesis in Y-1 and BAC with 22R-hydroxycholesterol and 25-hydroxycholesterol was performed and confirmed increased steroidogenesis; however, there was no effect on ouabain immunoreactivity content or release. Comparison of the ouabain binding density in cultured BAC, hepatoma cells, and 3T3 fibroblasts indicated that adrenocortical cells have a high ouabain-binding capacity. HPLC studies of the ouabain immunoreactivity released by bovine adrenocortical cells indicated that essentially no authentic ouabain was secreted. The present studies confirm that both BAC and Y-1 cultures release a ouabain-like material that differs in structure from authentic plant ouabain and is not a product of cholesterol side-chain cleavage.

Adrenal Cortex↗
PubMed1995

A recent measles outbreak in Arkansas.

On a worldwide level, measles is a common infection, especially in developing countries. In the United States, however, the disease has become very uncommon secondary to the widespread use of immunizations. Because of this, many physicians have not had measles themselves, nor have they treated patients for the infection. This relative rarity may delay diagnosis and the institution of appropriate infection control measures, thus resulting in increased numbers of exposed persons. Until measles is eradicated, measures to ensure appropriate immunization and control outbreaks are essential. A recent small outbreak in Arkansas is reported here along with a review of the disease and the measures to control outbreaks.

Adult↗
PubMed1992

Workplace compliance with a no-smoking law: a randomized community intervention trial.

BACKGROUND: Compliance with state and local laws restricting smoking in public places and workplaces has not been systematically evaluated. METHODS: We assessed workplace compliance with a comprehensive no-smoking law adopted in Brookline, Mass, and tested whether mailing information to businesses increased awareness of and compliance with the law. We conducted a random sample telephone survey of 299 businesses (87% response rate). Self-reported compliance was validated by direct observations. RESULTS: One year after its adoption, the law was popular with businesses. The prevalence of smoking restrictions, smoking policies, and no-smoking signs was 80%, 59%, and 40%, respectively. One third of businesses banned smoking. Full compliance with the law was low, however, because few businesses posted a copy of their smoking policy as required. The mailing increased employers' awareness of the law. Employers sent the mailing also reported better compliance, but this was not confirmed by direct observations. CONCLUSIONS: The law was popular and contributed to a high prevalence of workplace smoking restrictions. Different interpretations of the law by policymakers and businesses seemed to explain why formal compliance was low. The mailing increased awareness of, but not compliance with, the law.

Administrative Personnel↗
PubMed1988

Morbidity patterns from general practice in Cape Town. A pilot study.

A pilot survey of morbidity patterns reflected in general practice was undertaken by a panel of physicians in Cape Town during 1984-1985. Acute upper respiratory tract infections, bronchitis and bronchiolitis were the commonest reasons for contact. A definite pattern of contacts by day of week was noted. The age distribution of the contacts closely matched that of the suburb in which the practice was situated.

Adolescent↗