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Biomedical subjects

P Hill

Publications and source records attributed to P Hill.

At least 19 recordsLinked to original sources
PubMed1998

Population dose near the Semipalatinsk test site.

To determine the consequences of atmospheric atomic bomb tests for the population in the surroundings of the former nuclear weapons test site near Semipalatinsk in Kazakhstan, a pilot study was performed by an international cooperation between Kazakh, French, Czech and German institutions at two villages, Mostik and Maisk. Together with Kazakh scientists, eight experts from Europe carried out a field mission in September 1995 to assess, within the framework of a NATO supported project, the radiological situation as far as external doses, environmental contamination and body burden of man were concerned. A summary of the results obtained is presented. The actual radiological situation near the test site is characterized by fallout contaminations. Cs was found in upper soil layers in concentrations similar to those of the global fallout. Also Sr, Am and Co were observed. The resulting present dose to the population is low. Mean external doses from soil contamination for Maisk and Mostik (0.60-0.63 mSv/year) presently correspond to mean external doses in normal environments. Mean values of the annual internal doses observed in these two villages are below 2 microSv/year for 90Sr. For other radionuclides the internal doses are also negligible.

Biological Assay↗
PubMed1998

Helicobacter pylori in ectopic gastric mucosa in Meckel's diverticulum.

We report a case of a 25-year-old man who presented with a large rectal bleed and positive Meckel's scan followed by surgical excision of a Meckel's diverticulum. The diverticulum was lined by gastric body type mucosa showing evidence of active chronic gastritis associated with the presence of Helicobacter pylori organisms, these being identified immunohistochemically with a specific polyclonal antibody. We have reviewed another 21 cases of Meckel's diverticula removed at St Vincent's Hospital between 1984 and 1997: in nine of these cases the diverticulum was lined by ectopic gastric body type mucosa and in one of these there was an active chronic gastritis associated with Helicobacter pylori. There has been considerable controversy regarding both the presence and significance of Helicobacter organisms in Meckel's diverticula. This is the first study to use immunohistochemistry specifically to identify Helicobacter pylori within two cases of Meckel's diverticula. Both cases demonstrated an active chronic gastritis present within the gastric body type mucosa, thus suggesting that the organisms play a pathogenic role.

Adult↗
PubMed1998

The Escherichia coli chaperonin 60 (groEL) is a potent stimulator of osteoclast formation.

Chaperonins (cpns) are intracellular oligomeric protein complexes that fold and refold proteins in a catalytic manner and aid in the transmembrane transport of cellular proteins. We reported previously that the lipopolysaccharide-free recombinant cpn60 of Escherichia coli (groEL) is able to stimulate the breakdown of murine calvarial bone in culture and showed that such resorption is potently inhibited by an inhibitor of the enzyme cyclo-oxygenase and to a lesser extent by inhibitors of 5-lipoxygenase. In this study, we have investigated the effects of groEL on the resorptive activity and formation of osteoclasts in culture. In low density, osteoclast-containing cultures from neonatal rats incubated for 24 or 96 h on dentine discs, groEL (1-1000 ng/ml) stimulated resorption pit formation up to 4-fold, but this effect was essentially dependent on cell number. Using 12-day cultures of mouse bone marrow to assess osteoclast recruitment, groEL (1-1000 ng/ml) caused a dramatic dose-dependent stimulation of the formation of tartrate-resistant acid phosphatase-positive multinucleated cells and the resorption of the dentine on which bone marrow cells were cultured. Osteoclast formation elicited by groEL was almost completely abolished by indomethacin, an inhibitor of cyclo-oxygenase, but was unaffected by inhibitors of 5-lipoxygenase, suggesting that prostaglandins but not leukotrienes may mediate the action of groEL on osteoclastogenesis. It is possible that bacterial cpn60s such as groEL may play a role in the osteolysis associated with bone infections. Whether endogenous ("self") chaperonins have a role in other bone loss disorders, such as osteoporosis, is an intriguing possibility.

Acid Phosphatase↗
PubMed1997

Artificial insemination and in-vitro fertilization using donor spermatozoa: a report on 15 years of experience.

Donor insemination (DI) using cryopreserved semen commenced at The Royal Women's Hospital in 1976. Over the next 15 years we performed 5953 treatment cycles to achieve 816 pregnancies (13.7% per cycle) and 706 live births. In-vitro fertilization (IVF) using donor spermatozoa commenced in 1986. Over the next 5 years we performed 303 treatment cycles for 185 couples. Including subsequent transfer of cryopreserved embryos, a total of 33% of couples achieved a successful pregnancy by IVF. Statistical analysis indicated that, for DI pregnancies, the most important semen variable was the percentage post-thaw motility, whilst for normal fertilization in IVF it was the pre-freeze motility. These results may be explained by the compensatory effects of post-thaw processing of spermatozoa for IVF, but not for DI in our clinic.

Adolescent↗
PubMed1997

Public health in hospitals: new steps in old directions.

A pilot scheme of hospital epidemiologists in the Northern and Yorkshire region has provided an exciting opportunity to promote a public health perspective among hospital clinicians. Responsibilities and roles of the posts include the promotion of clinical effectiveness and evidence-based practice, epidemiological support for audit, research and clinical evaluation, liaison with primary care and public health colleagues in health authorities, and the development and implementation of clinical guidelines. Although the posts are not restricted to public health specialists, public health training and skills provide an excellent foundation from which to meet the challenges that arise from the posts. We discuss some of the lessons learnt by two public health doctors from the early steps in this new direction.

Career Mobility↗
PubMed1997

Effects of parity and weaning practices on breastfeeding duration.

The purpose of this project was to examine (a) patterns of breastfeeding and (b) duration with parity and breastfeeding experience, and (c) mothers' reasons for termination of breastfeeding. A convenience sample of 120 breastfeeding mothers was followed by home visits and telephone for 20 weeks after delivery. The sample consisted of 69 primiparas, 40 multiparas with previous breastfeeding experience, and 11 multiparas with no prior breastfeeding experience. Parity was not significantly associated with the continuation of breastfeeding but there was a trend toward a difference made by breastfeeding experience. Inadequate milk supply and employment were the two most common reasons reported for weaning. Implications for support in the workplace and for first-time breastfeeding mothers are discussed.

Adult↗
PubMed1997

Tachycardia-induced cardiomyopathy secondary to right ventricular outflow tract ventricular tachycardia: improvement of left ventricular systolic function after radiofrequency catheter ablation of the arrhythmia.

INTRODUCTION: Several reports describe development of cardiomyopathies secondary to supraventricular tachycardia. Few reports have described cardiomyopathies secondary to ventricular tachycardia. METHODS AND RESULTS: We describe a patient who presented with dilated cardiomyopathy and repetitive nonsustained monomorphic ventricular tachycardia. Cardiac catheterization showed hemodynamically insignificant coronary artery disease. Radiofrequency ablation of a right ventricular outflow tract ventricular tachycardia resulted in improvement of the left ventricular systolic function and resolution of heart failure symptoms. CONCLUSIONS: This report suggests that right ventricular outflow tract ventricular tachycardia may cause reversible tachycardia-induced cardiomyopathy.

Aged↗
PubMed1996

Effect of microwave heating on leaching of lead from old ceramic dinnerware.

When samples of pre-1950s U.S.-made ceramic dinnerware, purchased in antique shops and flea markets, were filled with 4% acetic acid or 0.5% citric acid and heated in a microwave oven for 2-5 min, lead was leached in amounts of up to 5 mg per dish. Concentrations of lead in the leachates were not significantly correlated with, and could not be predicted from, concentrations in leachates measured during 24-h room temperature acid leaching tests. Unsafe lead concentrations (>3 microg/ ml) were found in microwave leachates of dishes with uranium-containing glazes, with copper-containing glazes, and with floral over-the-glaze decals. This evidence suggests that use of such dishes to microwave common foods could result in the ingestion of dangerously large amounts of lead.

Acetic Acid↗
PubMed1996

Continuing professional education: a challenge for rural health practitioners.

Health professionals in rural and remote areas of Australia are disadvantaged when accessing continuing education. Their geographical isolation influences attendance at seminars, workshops and even informal discussions with colleagues. This paper describes the strategies adopted to meet the continuing education needs of a group of health professionals working in diabetes education and discusses how other specialist areas can provide similar educational opportunities. The education programs for isolated health professionals involved in diabetes care in South Australia were created by a team, and the resources of their associated institutions. Formal working agreements were established to achieve the aim of relevant continuing education for rural health professionals and to ensure ongoing ventures. All programs have been positively received, and evaluations identify the need to develop other, related subjects. Future developments will further utilise advances in technology to extend access and add to the current modes of education delivery. It is the intention of this group to continue to develop practice-based subjects capable of meeting rural health practitioners' needs and thus enhance the quality of care in rural and remote communities.

Diabetes Mellitus↗
PubMed1996

Leucocytoclastic vasculitis in a patient with azathioprine hypersensitivity.

We report the case of a 77-year-old man admitted nine days after being commenced on azathioprine with symptoms initially thought to be secondary to sepsis but in fact due to azathioprine hypersensitivity. He developed histologically proven cutaneous leucocytoclastic vasculitis following the re-introduction of azathioprine. We review the literature concerning adverse reactions to azathioprine and the problems of making the diagnosis as well as highlighting azathioprine as a novel cause of leucocytoclastic vasculitis.

Aged↗
PubMed1996

Effect of inhaled morphine on the development of breathlessness during exercise in patients with chronic lung disease.

BACKGROUND: Inhaled morphine has previously been shown to increase exercise endurance in patients with chronic lung disease. A similar study was performed to determine whether inhaled morphine reduces the sensation of breathlessness in this group of patients. METHODS: A randomised double blind study on the effect of nebulised morphine on both exercise induced breathlessness and maximum achievable power output using isotonic saline as a control was performed in 10 patients with stable chronic lung disease. Each subject performed a progressive exercise test (Jones' stage I) on an electrically braked cycle ergometer. The work load was increased by 10 watts per minute and subjects exercised to exhaustion. At the end of each minute of exercise patients were asked to rate their degree of breathlessness according to a modified Borg scale. All subjects were randomised to receive either inhaled morphine sulphate 1 mg/ml (5 ml) or isotonic saline (5 ml) by wet nebulisation. The effect of morphine and saline on the achieved exercise capacity and the development of breathlessness during exercise was tested on separate days. RESULTS: The mean dose of morphine inhaled was 1.24 mg. There was no difference in maximum power output achieved, minute ventilation at maximum power output, nor the degree of breathlessness at maximum power output between the groups treated with morphine and placebo. The degree of breathlessness was related to the power output achieved during exercise by a power function relationship (mean r: morphine = 0.86, saline = 0.87). However, there was a wide variation in the sensation for any given power output in both groups. There was no difference in the group mean slopes (morphine = 1.15, saline = 1.00) or intercepts (morphine = 0.07, saline = 0.15) in this relationship between the morphine and saline treatment groups. CONCLUSIONS: In patients with severe chronic lung disease inhaled morphine in the doses used in this study does not relieve exercise induced breathlessness nor does it increase maximum power output achieved during progressive exercise.

Administration, Inhalation↗
PubMed1996

Captopril preserves function and ultrastructure in experimental radiation nephropathy.

Captopril protects rat lung from radiation-induced pneumonitis and fibrosis and preserves function and survival in experimental radiation nephropathy. This study determined the structural benefit of captopril used preventively in radiation nephropathy. Twenty-eight Wag/RijMCW rats, divided in six groups, received 0 to 17 Gray total body irradiation followed by syngeneic bone marrow transplant. Captopril 0, 62.5, 125, 250, or 500 mg/l was given in the drinking water from the time of irradiation, and the rats were killed at 20 weeks. Using light and electron microscopy, kidneys of irradiated no-drug rats showed glomerular tuft capsular adhesions and hyalinization, focal tubular necrosis, severe interstitial fibrosis, and marked thickening and hyaline degeneration of the wall of interlobular arteries and arterioles, with intimal proliferation and periadventitial edema and inflammation. Lumens of the smaller arteries were often occluded. Significant collagen deposition was present in glomeruli, interstitium, and adventitia of interlobular arteries. Marked reduction of glomerular, tubular, vascular, and interstitial damage was seen in irradiated, captopril-treated animals, with only mild focal tubular interstitial injury and fibrosis seen. alpha smooth muscle actin-positive cells, probably myofibroblasts, were enhanced in the irradiated kidneys, and this expression was reduced in a dose-related fashion by captopril. There was also reduction in the arteriolar wall thickening, luminal occlusion, and collagen deposition in captopril-treated animals. The presence of elastin was not affected by radiation or drug treatment. Blood pressure and azotemia were lower and survival was higher in irradiated drug-treated rats compared with irradiated no-drug rats. We conclude that captopril exerts significant functional and structural protection against renal radiation injury. There was notable reduction in radiation-induced fibrosis in captopril-treated animals in this model, as in experimental lung radiation injury.

Angiotensin-Converting Enzyme Inhibitors↗