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Biomedical subjects

J Whitworth

Publications and source records attributed to J Whitworth.

69 records · Page 4Linked to original sources
PubMed1996

Sexual mixing patterns in Uganda: small-time urban/rural traders.

OBJECTIVE: To document the extent to which rural and urban-based male traders have sexual contacts away from their place of residence. METHODS: Fifty-one traders (46 who travel by bicycle and five others) kept daily diaries of all their journeys and sexual contacts for a total of 584 person-weeks. Twenty-five were resident in a trading town where HIV prevalence was about 40% and 26 lived up to 25 km away in rural areas where HIV prevalence was approximately 8%. RESULTS: A total of 2147 return trips were made (mean, 3.7 per week). Eighty per cent were between the trading town and the surrounding rural area. A total of 1377 sexual contacts were recorded (mean, 2.3 per week); 95% of the contacts of urban-based men occurred in the town, 3% in other urban areas and 2% in a rural area. For rural-based men 82% of sexual contacts took place in their home village, 14% in a neighbouring village, 2% in the trading town and 3% in other urban centres. CONCLUSION: Despite considerable economic interaction there is very little sexual mixing between the town and surrounding rural areas. This may explain why the high HIV prevalence found in some trading towns in Africa has not diffused out to rural areas.

Adult↗
PubMed1995

Impregnation by dentine bonding agents into instrumented root-face dentine.

OBJECTIVES: To examine the penetration of unfilled resin into instrumented root-face dentine, facilitated by five commercially available dentine bonding agents. METHODS: Upper third molar teeth were decoronated, and a given dentine bonding agent and resin composite applied to the instrumented root face, according to the manufacturer's instructions. A control specimen was similarly prepared but not dentine primer was applied prior to resin composite. The teeth were sectioned longitudinally and the sectioned surface demineralized and deproteinated. Specimens were examined by scanning electron microscopy (SEM) for resin tag length and density in different areas of the root face. RESULTS: Specimens treated with dentine bonding agent systems exhibited minimum resin penetration of peripheral root-face dentine and much longer penetration of resin tags in dentine above the pulp chamber. A possible 'hybrid' layer of resin-impregnated dentine was observed in all specimens where a dentine bonding agent system had been used but was not observed in control specimens. Resin tags were also more sparsely observed in control specimens. CONCLUSION: Resin tag penetration is superior in both density and length of penetration in dentine overlying and adjacent to the pulp chamber, with shorter and sparser penetration exhibited in peripheral root-face dentine. The possible clinical implications of these observations are discussed.

Adhesiveness↗
PubMed1992

Treatment of onchocerciasis with ivermectin in Sierra Leone.

Ivermectin chemotherapy is proving to be a major advance in the management of onchocerciasis. In this article, James Whitworth reviews the work done on onchocerciasis and ivermectin in Sierra Leone and examines the evidence that mass treatment might control the clinical features of the disease and its transmission in West Africa. Ivermectin is safe and effectively reduces microfilarial (mf) loads, with major improvement in some ocular manifestations o f disease. This alone makes mass distribution to communities at risk of blindness worthwhile, even though the impact on other clinical features is less clear cut. Repeated doses have a cumulative effect on adult worms, which may cause more reduction in transmission than hitherto thought likely.

Journal Article↗
PubMed1992

Identification and characterization of a parasite antigen in the circulating immune complexes of Onchocerca volvulus infected patients.

A PEG-ELISA was used to demonstrate parasite specific immune complexes in a significant proportion (25/26) of Onchocerca volvulus infection sera from Sierra Leone. The parasite antigen was detected using a peroxidase-conjugated rabbit serum raised to the bovine parasite O. gibsoni. Controls including European control serum, endemic control serum and Rh+ sera gave consistently low readings. Characterization of the parasite component in the immune complexes by Western blotting demonstrated a heat stable antigen of M(r) 46,000. This antigen was not present in the circulating immune complexes (CIC) prepared from patients with Wuchereria bancrofti infection, but a cross-reactive molecule of the same size was weakly recognized in the CIC of Loa loa and Mansonella perstans infected patients. No association between the level of parasite specific CIC and clinical disease was observed in the O. volvulus patients.

Animals↗
PubMed1991

Immunity to Onchocerca volvulus microfilariae in mice and the induction of cross-protection with O. lienalis.

Inbred CBA/Ca mice were vaccinated with Onchocerca volvulus or Onchocerca lienalis microfilariae (mf) and challenged 100 days later with the homologous or heterologous parasite. There was a major reduction in mf recoveries from immunised animals compared with controls when the sensitising and challenge infections were both of O. volvulus mf. Resistance was manifest within one week of challenge, and rose from an 87% reduction in recoveries on day 7 to a 96% reduction on day 15. Similar results were obtained for homologous sensitising and challenge infections with O. lienalis mf. Protection afforded by sensitisation with the heterologous parasite was also high, although the expression of resistance appeared to be delayed. Vaccination with O. lienalis mf led to a 45% level of cross-protection against O. volvulus at 7 days after challenge, which rose to 94% by day 15. Vaccination with O. volvulus mf stimulated cross-protection against O. lienalis at levels of 49% and 80% as measured 7 and 15 days after challenge. It is concluded that the mouse model may be of value in analysing immune responses directed against O. volvulus mf and that the cross-protection between Onchocerca species is an advantage that should be exploited in characterising the antigens involved.

Animals↗
PubMed1988

Isolation and in vitro translation of Onchocerca volvulus mRNA.

Adult Onchocerca volvulus recovered for excised nodules by dissection or treatment with collagenase have been used as a source of RNA for in vitro translation experiments. RNA was purified using either the hot phenol/SDS procedure or the guanidine isothiocyanate protocol. Immunoprecipitation experiments performed on in vitro products demonstrate a marked heterogeneity in responses by individed human infection sera. Further immunoprecipitation experiments demonstrate cross reactivity between O. volvulus and other filarial nematodes.

Animals↗
PubMed1986

Effects of heparin and defibrinotide on malignant hypertension in rats.

This study examines the effects of anticoagulant and antithrombotic drugs on blood pressure (BP), plasma renin activity (PRA) and renal glomerular and vascular lesions in rats following aortic ligation. Whole heparin, low molecular weight (LMW) heparin or defibrinotide was administered for 4 weeks to rats following complete aortic ligation between the renal arteries. BP and PRA in whole heparin treated rats were significantly lower than those in control rats (p less than 0.01, p less than 0.01). Renal morphology also revealed a reduced number of epithelial cell droplets (ECD) (the nature of which is unknown) in glomeruli and less severe vascular lesions (p less than 0.005, p less than 0.005). Decreased BP and PRA were seen in rats receiving LMW heparin, but the failure of LMW heparin to prevent vascular damage indicates that an increased anti-Xa activity or reduction of PRA is not enough to prevent these lesions in hypertensive rats. The rats receiving defibrinotide showed reduced BP only.

Animals↗
PubMed1985

Arteritis and venulitis in systemic lupus erythematosus resulting in massive lower intestinal haemorrhage.

A case of systemic lupus erythematosus with massive haemorrhage from the colon is described. Histological examination showed ulceration of the mucosa of the ascending colon with necrotizing vasculitis of the submucosal veins. Adjacent arteries were normal apart from one which had ruptured on the surface of an ulcer. This is the first clearly documented case of colonic venulitis in systemic lupus erythematosus and the differential diagnosis of gastrointestinal haemorrhage in this disease is discussed.

Adolescent↗
PubMed1977

Acute glomerulonephritis in children: a review of 153 cases.

Clinical experience with 153 cases of acute glomerulonephritis is recorded. Streptococcal impetigo was the major causative factor in this series. The acute fatality rate was 1.3% (two patients). Of the 151 survivors, 103 patients have been followed up for periods of six months to 11 years. None of these patients have shown any evidence of progression to chronic glomerulonephritis. In this series, as in others previously reported, acute glomerulonephritis in children appears to be self-limited in contrast to the illness in adults, where 25% to 40% of the cases progress to chronic glomerulonephritis. Unusual findings in this survey were ten patients with minimal or no urine abnormalities. Ten patients had normal serum complement values and three patients had well documented second attacks of poststreptococcal glomerulonephritis.

Acute Disease↗
PubMedDate not supplied

Ocular findings in HIV-1 positive and HIV-1 negative participants in a rural population-based cohort in Uganda.

PURPOSE: To report the ocular findings in HIV-1 seropositive individuals and HIV-negative controls in a population-based cohort in rural Uganda. METHODS: Participants were examined by an ophthalmologist, who was unaware of their HIV-status. RESULTS: 238 participants were examined, 43 were HIV-1 prevalent cases (infected prior to 1990); 62 were HIV-1 incident cases and 133 were HIV-negative controls. Eleven of the HIV-positive participants had AIDS, and a further 8 had a CD4 count of less than 200 cells/mm3. Bilateral low vision was recorded in 9 participants and cataracts were the main cause of bilateral low vision. The mean intra-ocular pressure (IOP) was 12.6 mm Hg, and no association was found between IOP and CD4 lymphocyte count. Although significantly more HIV positives had some sign of intraocular inflammation compared to the negatives (p = 0.02) there was no significant linear trend in the HIV positives with decreasing CD4 count. Overall, 11 (26%) prevalent, 6 (10%) incident cases and 8 (6%) HIV-negatives controls had some evidence of intraocular inflammation, however, only one person had reduced visual acuity attributable to these lesions. Punctate epithelial erosions and keratic precipitates in the anterior chamber were seen significantly more frequently in HIV-positives compared to the HIV-negative controls. Cotton wool spots were not seen. CONCLUSIONS: A substantial proportion of HIV-infected persons had ocular findings which may have been attributable to their infection, however in only one case did this result in reduced visual acuity. Although the ocular complications of AIDS seem to comprise a large extra element in the work load of tertiary care hospitals dealing with eye problems, on a population basis such cases are infrequent.

Adult↗
PubMedDate not supplied

Managing patient demographics.

The Harvard Community Health Plan commissioned a cross-functional project team to improve the accuracy of the members' data base because inaccurate patient phone numbers and addresses were a major obstacle for clinicians seeking to provide high-quality service to patients. Accurate demographic information is essential to enable clinicians to contact patients quickly regarding lab results or follow-up care. The team members applied a quality improvement problem-solving methodology that required them to focus on the few vital problems and to test problems using data analysis. As a result, the team saw firsthand that staff members were not to blame for the inaccurate demographic information; the problem was in the automated system that obtains, updates, and maintains the records.

Ambulatory Care Information Systems↗
PubMedDate not supplied

Cost-effectiveness analysis in the treatment of hypertension: a medical view.

The clinical benefits of anti-hypertensive treatment include reductions in stroke and myocardial infarction, heart failure, renal and ocular damage and possibly cognitive impairment. The cost-effectiveness of treatment generally falls within a range considered acceptable to funders of health care in developed countries, and has been shown to vary with age, gender and pre-treatment blood pressure. In a largely asymptomatic condition, small quality of life impairments resulting from treatment could offset these clinical and economic benefits, but evidence suggests that treatment is associated with slight improvements in quality of life. A limitation of these analyses is that the needs of developing countries are not met. The cost-effectiveness of anti-hypertensive treatment may be unattractive to developing countries when compared with interventions that achieve greater health gains per dollar spent.

Adult↗
PubMedDate not supplied

1999 World Health Organization-International Society of Hypertension Guidelines for the management of hypertension. Guidelines sub-committee of the World Health Organization.

The present Guidelines were prepared by the Guidelines Sub-Committee of the World Health Organization-International Society of Hypertension (WHO-ISH) Mild Hypertension Liaison Committee, the members of which are listed at the end of the text. These guidelines represent the fourth revision of the WHO-ISH Guidelines and were finalised after presentation and discussion at the 7th WHO-ISH Meeting on Hypertension, Fukuoka, Japan, 29th Sept-1st Oct, 1998. Previous versions of the Guidelines were published in Bull WHO 1993, 71:503-517 and J Hypertens 1993, 11:905-918.

Adult↗