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Biomedical subjects

D Cooper

Publications and source records attributed to D Cooper.

At least 37 records · Page 2Linked to original sources
PubMed1998

Improving the yield of blood cultures for patients with early Lyme disease.

This study was designed to improve the recovery of Borrelia burgdorferi from blood. With the techniques used, B. burgdorferi could be recovered from the blood of approximately 25% of patients with early Lyme disease associated with erythema migrans. Serum was a better source of culture material than whole blood. The volume of blood cultured correlated directly with yield, particularly for patients with a single erythema migrans lesion.

Adult↗
PubMed1998

Gay men who engage repeatedly in unprotected anal intercourse with casual partners: the Sydney Men and Sexual Health Study.

We set out to determine the frequency and correlates of gay men's repeated unprotected anal intercourse with casual partners (UAI-C), defined as UAI-C reported at each of 3 annual interviews. By May 1997, 659 men had completed 3 annual interviews for the Sydney Men and Sexual Health (SMASH) cohort study. For the 3 6-month periods prior to each interview, 127 men reported UAI-C during one period only; 45 reported it during 2 periods; and 20 men reported it during all 3 periods. These 20 men who had repeated UAI-C were compared with 497 men who had anal intercourse with casual partners but did not report on all 3 occasions that they had UAI-C. Logistic regression revealed that repeated UAI-C was associated with HIV-positive status, more casual partners, less favourable attitudes toward condoms and greater recreational drug use. Few gay men have repeated UAI-C but those who do run greater risk of HIV transmission.

Adult↗
PubMed1998

A survey of consultants treating upper aerodigestive tract cancer in the UK.

A study was undertaken to determine the current service provision for the treatment of upper aerodigestive tract (UAT) cancers in the UK. A postal questionnaire was sent to all consultant members of relevant specialist societies, with 1041 (74%) responding. Treatment of UAT cancer is widely dispersed with over 900 consultants from five major disciplines treating, on average, less than 10 cases per year. There were few regional or provider differences in the facilities and services available and in processes used for assessing patients. There is little systematic collection of data for audit or research and some consultants do not record stage. The involvement of other disciplines in the assessment process, use of joint clinics, counselling, specialist nursing and therapy services appears to be low. There is a need for rationalisation of head and neck cancer services; for more systematic collection of data for audit and research and for improvements in the use of joint clinics and support services.

Cancer Care Facilities↗
PubMed1997

Regulation of antigen-specific IgE, IgG1, and mast cell responses to ingested allergen by mucosal tolerance induction.

Mucosal administration of soluble protein Ags results in profound immunologic nonresponsiveness, characterized by reduced production of Th1 and Th2 cytokines and concomitant suppressed Ig production. It has been suggested that Th2 cells are required for the induction and maintenance of this tolerogenic state. In this study, we show that oral tolerance induction abrogates subsequent Th2-driven Ag-specific IgE and IgG1 responses, while intranasal tolerance induction only blocks the production of IgE, but not IgG1. Consistent with suppressed IgE serum levels, elevated IFN-gamma production was observed in the spleens of tolerized mice. Moreover, both oral and intranasal tolerance induction were found to inhibit intestinal mast cell responses upon subsequent priming and intragastric provocation. Transfer of total splenocytes or purified CD4+, but not CD8+, T cells from intranasally tolerized mice clearly suppressed ongoing Ag-specific IgE, but not IgG1, responses in primed recipients. In addition, coadministration of IFN-gamma-neutralizing Abs completely blocked the transfer of suppression to primed recipients. These results show that Th2 cells can be subjected to tolerance induction, by inducing cross-regulatory, IFN-gamma-producing CD4+ T cells. Moreover, our results point out differences in the regulation of T cell-dependent Ag-specific IgE and IgG1 responses.

Animals↗
PubMed1997

Changes in gravity inhibit lymphocyte locomotion through type I collagen.

Immunity relies on the circulation of lymphocytes through many different tissues including blood vessels, lymphatic channels, and lymphoid organs. The ability of lymphocytes to traverse the interstitium in both nonlymphoid and lymphoid tissues can be determined in vitro by assaying their capacity to locomote through Type I collagen. In an attempt to characterize potential causes of microgravity-induced immunosuppression, we investigated the effects of simulated microgravity on human lymphocyte function in vitro using a specialized rotating-wall vessel culture system developed at the Johnson Space Center. This very low shear culture system randomizes gravitational vectors and provides an in vitro approximation of microgravity. In the randomized gravity of the rotating-wall vessel culture system, peripheral blood lymphocytes did not locomote through Type I collagen, whereas static cultures supported normal movement. Although cells remained viable during the entire culture period, peripheral blood lymphocytes transferred to unit gravity (static culture) after 6 h in the rotating-wall vessel culture system were slow to recover and locomote into collagen matrix. After 72 h in the rotating-wall vessel culture system and an additional 72 h in static culture, peripheral blood lymphocytes did not recover their ability to locomote. Loss of locomotory activity in rotating-wall vessel cultures appears to be related to changes in the activation state of the lymphocytes and the expression of adhesion molecules. Culture in the rotating-wall vessel system blunted the ability of peripheral blood lymphocytes to respond to polyclonal activation with phytohemagglutinin. Locomotory response remained intact when peripheral blood lymphocytes were activated by anti-CD3 antibody and interleukin-2 prior to introduction into the rotating-wall vessel culture system. Thus, in addition to the systemic stress factors that may affect immunity, isolated lymphocytes respond to gravitational changes by ceasing locomotion through model interstitium. These in vitro investigations suggest that microgravity induces non-stress-related changes in cell function that may be critical to immunity. Preliminary analysis of locomotion in true microgravity revealed a substantial inhibition of cellular movement in Type I collagen. Thus, the rotating-wall vessel culture system provides a model for analyzing the microgravity-induced inhibition of lymphocyte locomotion and the investigation of the mechanisms related to lymphocyte movement.

Animals↗
PubMed1997

Women's health status and use of health services in a rapidly growing peri-urban area of South Africa.

Women's health in South Africa and particularly women living in peri-urban areas is being influenced by three major factors. These include the political transition that is occurring in the country, urbanization and the international interest in women's health. Changes in the delivery of health care to the population, and in particular to women are being planned. It is therefore important that data are available for the purpose of planning and evaluation of health services. This paper describes a household survey in which 661 women were interviewed. Socio-demographic patterns of women living in a rapidly urbanizing area were determined and related to health status, use of health services and knowledge of the services. Poverty appeared to be an overriding factor affecting the health of the population. One third of the women were living in unserviced shacks. There was a high rate of unemployment and those who were employed worked in low status jobs and earned very little. Rates of reported acute and chronic illness were lower than described elsewhere in similar household interview surveys. A third of the acute illnesses were due to respiratory disease. Reported rates of diabetes and hypertension were low indicating undiagnosed disease in the area. Being a member of an alliance household-a mixture of family, friends and lodgers-was the main predictor of acute illness. For chronic disease, age and increasing educational status were the main predictors. Knowledge of services apart from those for cervical cancer screening was good. The latter improved with increasing education, urbanization and being a member of an alliance household. As many of the women lived in unserviced areas and had little or no income the provision of infrastructural services and development programs are essential if their health is to be improved. The existing health services need to be developed to provide a comprehensive primary care service with special attention being paid to the health of women. The service should be close to their homes and be affordable. The information gathered in this survey will be used to plan services for women in the area and will act as baseline data for evaluation.

Acute Disease↗
PubMed1997

Profile of SB-204269, a mechanistically novel anticonvulsant drug, in rat models of focal and generalized epileptic seizures.

1. Earlier optimization of structure-activity relationships in a novel series of 4-(benzoylamino)-benzopyrans, led to the discovery of SB-204269 (trans-(+)-6-acetyl-4S-(4-fluorobenzoylamino)-3,4-dihydro-2, 2-dimethyl-2H-benzo[b]pyran-3R-ol, hemihydrate), a potent orally-active anticonvulsant in the mouse maximal electroshock seizure threshold (MEST) test. 2. Studies have now been undertaken to determine the effects of SB-204269 in a range of seizure models and tests of neurological deficits in rats. In addition, the compound has been evaluated in a series of in vitro mechanistic assays. 3. SB-204269 proved to be an orally-effective anticonvulsant agent, at doses (0.1-30 mg Kg-1) devoid of overt behavioural depressant properties, in models of both electrically (MEST and maximal electroshock (MEST)) and chemically (i.v. pentylenetetrazol (PTZ) infusion)-evoked tonic extension seizures. However, the compound did not inhibit PTZ-induced myoclonic seizures at doses up to 30 mg kg-1, p.o. 4. SB-204269 also selectively reduced focal electrographic seizure activity in an in vitro elevated K+ rat hippocampal slice model at concentrations (0.1-10 microM) that had no effect on normal synaptic activity and neuronal excitability. 5. In all of these seizure models, SB-204269 was equivalent or better than the clinically established antiepileptic drugs carbamazepine and lamotrigine, in terms of anticonvulsant potency and efficacy. 6. Unlike SB-204269, the corresponding trans 3S,4R enantiomer, SB-204268, did not produce marked anticonvulsant effects, an observation in accord with previous findings for other related pairs of trans enantiomers in the benzopyran series. 7. In the rat accelerating rotarod test, a sensitive paradigm for the detection of neurological deficits such as sedation and motor incoordination, SB-204269 was inactive even at doses as high as 200 mg kg-1, p.o. This was reflected in the excellent therapeutic index (minimum significantly effective dose in the rotarod test/ED50 in the MES test) for SB-204269 of > 31, as compared to equivalent values of only 7 and 13 for carbamazepine and lamotrigine, respectively. 8. At concentrations (> or = 10 microM) well above those required to produce anticonvulsant activity in vivo (i.e. 0.1 microM in brain), SB-204269 did not interact with many of the well known mechanistic targets for established antiepileptic drugs (e.g. Na+ channels or GABAergic neurotransmission). Subsequent studies have shown that the anticonvulsant properties of SB-204269 are likely to be mediated by a novel stereospecific binding site present in the CNS. 9. The overall efficacy profile in rodent seizure models, together with a minimal liability for inducing neurological impairment and an apparently unique mechanism of action, highlight the therapeutic potential of SB-204269 for the treatment of refractory partial and generalized tonic-clonic seizures.

Animals↗
PubMed1997

Bowel management outcomes in individuals with long-term spinal cord injuries.

Outcomes of bowel management were evaluated in 1993 among 221 British long-term spinal cord injury survivors who were followed-up as part of a longitudinal study of aging with spinal cord injury. Representing a population-based sample followed up by two regional spinal cord injury treatment centres - Stoke Mandeville Hospital in Aylesbury and the District General Hospital in Southport, England - all had been injured at least 20 years when the study was begun in 1990; all underwent comprehensive assessments and extensive interviewing at their centres in 1990 and 1993. When assessed in 1993, 42% of the entire sample reported constipation, 35% reported gastrointestinal pain, and 27% complained of bowel accidents. Physician examiners diagnosed significantly more hemorrhoids among those using primarily suppositories and enemas to manage their bowels (P < 0.05) and more constipation among persons with paraplegia (P < 0.05) and those using digital stimulation, manual evacuation, or increased abdominal pressure in their bowel programs. Fecal incontinence and diarrhea was diagnosed three times more often in participants with tetraplegia as in other neurological groupings. These and other findings suggest future research needs and directions relative to long-term bowel management for spinal cord injury survivors.

Aging↗
PubMed1997

Efficacy of a 2-mm spot size lens for the treatment of superficial vascular lesions with a flashlamp-pumped dye laser.

BACKGROUND: The flashlamp-pumped dye laser, using either a 3 or 5 mm spot size, is an excellent instrument for the treatment of port-wine stains and other superficial cutaneous vascular lesions. Problems exist with patient acceptance due to prominent and prolonged blue-black discoloration and the pain associated with the treatment. OBJECTIVE: To assess the effectiveness of a flashlamp-pumped dye laser equipped with a 2 mm spot size lens in the treatment of superficial vascular lesions. METHODS: Twenty-one patients with telangiectasias, cherry angiomas, and angiokeratomas were treated at a variety of fluences. RESULTS: Three of 21 patients had complete clearing of their superficial vascular lesions. An improvement of greater than 75% was noted by 11 patients, and six patients noted a 50%-75% improvement. One patient had less than 50% improvement. Less post-treatment discoloration and less pain were noted with the 2 mm spot size lens. CONCLUSIONS: The 2 mm spot size lens, used with the flashlamp-pumped dye laser is an effective instrument for the treatment of superficial cutaneous vascular lesions.

Adult↗
PubMed1997

Sexual negotiation in the AIDS era: negotiated safety revisited.

OBJECTIVE: To test the safety of the 'negotiated safety' strategy-the strategy of dispensing with condoms within HIV-seronegative concordant regular sexual relationships under certain conditions. METHOD: Data from recently recruited cohort of homosexually active men (Sydney Men and Sexual Health cohort, n = 1037) are used to revisit negotiated safety. The men were surveyed using a structured questionnaire and questions addressing their sexual relationships and practice their own and their regular partner's serostatus, agreements entered into by the men concerning sexual practice within and outside their regular relationship, and contextual and demographic variables. RESULTS: The findings indicate that a significant number of men used negotiated safety as an HIV prevention strategy. In the 6 months prior to interview, of the 181 men in seroconcordant HIV-negative regular relationships, 62% had engaged in unprotected anal intercourse within their relationship, and 91% (165 men) had not engaged in unprotected anal intercourse outside their relationship. Of these 165 men, 82% had negotiated agreements about sex outside their relationship. The safety of negotiation was dependent not only on seroconcordance but also on the presence of an agreement; 82% of the men who had not engaged in unprotected anal intercourse outside their regular relationship had entered into an agreement with their partner, whereas only 56% of those who had engaged in unprotected anal intercourse had an agreement. The safety of negotiation was also related to the nature of the safety agreement reached between the men and on the acceptability of condoms. Agreements between HIV-negative seroconcordant regular partners prohibiting anal intercourse with casual partners or any form of sex with a casual partner were typically complied with, and men who had such negotiated agreements were at low risk of HIV infection. CONCLUSIONS: The adoption of the strategy of negotiated safety among men in HIV-seronegative regular relationships may help such men sustain the safety of their sexual practice.

Adolescent↗
PubMed1997

Urbanisation and women's health in South Africa.

For many decades the migrant labor system and the influx control legislation in South Africa exacerbated male-dominant patterns of migration typical of Africa. In recent years, however, and especially following the easing of influx control legislation in 1986, migration in South Africa has increasingly involved women. This paper reports on a study conducted in Khayelitsha, Cape Town, which explored the relationship between urbanisation and the health of women. The objectives were to relate age, migration, length of stay in urban areas, employment status, and occupation to the health, including reproductive health, of women living in Khayelitsha. Interviews with 659 women (61 households had no senior woman) revealed that women enjoyed considerable social support through their neighbours, church organisations, and women's organisations. Women who lived in the most deprived section of Khayelitsha enjoyed more support from their neighbours but reported less satisfaction with the area in which they lived. Child-care support was poor and a considerable proportion of the women were disempowered by their male partners. More than 90 percent of the women had access to antenatal care. Recent immigrants had more pregnancies, were less aware of screening for cervical cancer, less likely to have had a Pap smear, less knowledgeable about where to have a Pap smear done, and less likely to have heard AIDS. More women were aware of AIDS (86%) than Pap smears (45%). More than half of those of childbearing age used contraception, mainly intramuscular hormones (76%). A significant proportion (53%) of the women reported that they had had their first pregnancy as teenagers and younger, less educated women were more likely to have had adolescent pregnancies. Policy makers are confronted by a compelling need to redress well-known urban-rural inequalities in health care in South Africa. Policy attention must also be given to the increasing urbanisation of women and the growing health care needs in urban areas.

Adult↗
PubMed1997

Gay youth and their precautionary sexual behaviors: the Sydney men and sexual health study.

Many commentators have positioned Western gay youth as a high-risk group for HIV infection and obscured important cultural, social, and contextual differences between populations. This study compares risk of HIV transmission factors among 216 young (under 25 years) and 822 older (25 years or over) homosexually active men, recruited through Sydney gay community and other sources. Bivariate and multivariate analyses of survey data that were collected by personal interviews consistently supported our hypothesis of no difference in HIV-related risk factors between young and older men. Although young men in this cohort were more likely to be of unknown serostatus, they were at least as knowledgeable, as attached to gay community, and as precautionary in their sexual behaviors with regular and casual male partners as their older counterparts. Safety campaigns targeting these young gay men should focus, for example, on their lower rates of HIV antibody testing and not be based on a false premise of hedonistic, uninformed, and disenfranchised youth.

AIDS Serodiagnosis↗