Search PubMed⌕ Search

Biomedical subjects

S Bennett

Publications and source records attributed to S Bennett.

At least 19 recordsLinked to original sources
PubMed2000

Antibacterial mesh sling: a prospective outcome analysis.

OBJECTIVES: To prospectively assess the outcome results of the Gore-Tex antibacterial mesh sling in women with pelvic prolapse and stress incontinence. METHODS: Between July 1997 and November 1998, 30 women with stress incontinence and vaginal prolapse underwent vaginal reconstruction with the antibacterial mesh sling. All patients had documented stress incontinence by preoperative urodynamic evaluation. Postoperatively, we conducted an outcome analysis on the basis of the results from a self-reported satisfaction questionnaire, a detailed pelvic examination, a cough stress test, and the Q-tip test. Urodynamic studies were performed on patients with persistent stress incontinence or urge symptoms. Cystoscopy was performed on patients suspected of having urethral erosion. RESULTS: Complete follow-up was available for all 30 patients. Of the group, 12 (40.0%) of 30 underwent implantation of the antibacterial mesh sling alone and 18 (60.0%) underwent additional prolapse repair. The mean follow-up was 18 months (range 9 to 24); mean age was 58 years (range 29 to 87). Stress incontinence was cured in 28 (93.3%) of 30 patients. De novo urge incontinence developed in 1 (5.2%) of 18 patients; urge symptoms persisted in 5 (41.7%) of 12 patients. The postoperative mean Valsalva Q-tip angle was 15 degrees (range 0 degrees to 25 degrees ). The incidence of urethral obstruction and erosion was zero. The mean postoperative pain score was 3 of 10 (range 0 to 6), and the mean satisfaction score was 9 of 10 (range 7 to 10). The mean time to discharge was 21 hours (range 6 to 29). All 30 women (100%) were willing to undergo surgery again. CONCLUSIONS: The safety profile of the Gore-Tex antibacterial mesh is better than that of the conventional Gore-Tex sling. When meticulous surgical technique is used, excellent short-term results can be achieved in the correction of female stress incontinence.

Adult↗
PubMed2000

The response of providers to capitation payment: a case-study from Thailand.

Those designing payment systems for health care in low and middle income countries are increasingly looking to capitation payment, in order to avoid the cost inflation experienced with fee-for-service payment. However, there is virtually no documentation of the experience of introducing capitation payment, or of its effects. This paper draws on several research studies to explore responses by health care providers at both the market and facility level to the introduction of capitation payment, in the context of a new compulsory insurance scheme for workers in Thailand. The paper ends by identifying lessons for both Thailand itself and for other countries.

Capitation Fee↗
PubMed2000

Synthesis and evaluation of C-9 modified N-acetylneuraminic acid derivatives as substrates for N-acetylneuraminic acid aldolase.

Several C-9 modified N-acetylneuraminic acid derivatives have been synthesised and evaluated as substrates of N-acetylneuraminic acid aldolase. Simple C-9 acyl or ether modified derivatives of N-acetylneuraminic acid were found to be accepted as substrates by the enzyme, albeit being transformed more slowly than Neu5Ac itself. 1H NMR spectroscopy was used to evaluate the extent of the enzyme catalysed transformation of these compounds. Interestingly, the chain-extended Neu5Ac derivative 16 is not a substrate for N-acetylneuraminate lyase and behaves as an inhibitor of the enzyme.

Bacterial Proteins↗
PubMed2000

Implicit learning differences: a question of developmental level?

A. S. Reber's (1992) proposition that the implicit learning system should demonstrate invariance of intellectual level (IQ) was examined by comparing 20 children with intellectual disability (mean mental age [MA] = approximately 5.8 years) with 20 intellectually gifted children (mean MA = approximately 12.4 years) of similar chronological age (CA; approximately 9.5 years). Implicit learning was assessed using a task involving covariation of 2 incidental cues. Explicit learning was assessed using a task of similar logical structure. Contrary to the IQ-invariance proposition, implicit learning as well as explicit learning varied with intellectual level. A secondary aim was to distinguish the contributions of CA, IQ, and MA to implicit learning. This was done by combining the samples of children in the present study with 2 samples of younger and older children of average ability from a study by M. Maybery, M. Taylor, and A. O'Brien-Malone (1995). Analyses showed that MA is critical to implicit learning.

Association Learning↗
PubMed2000

Theory and practice in sport psychology and motor behaviour needs to be constrained by integrative modelling of brain and behaviour.

Because of advances in technology, the non-invasive study of the human brain has enhanced the knowledge base within the neurosciences, resulting in an increased impact on the psychological study of human behaviour. We argue that application of this knowledge base should be considered in theoretical modelling within sport psychology and motor behaviour alongside existing ideas. We propose that interventions founded on current theoretical and empirical understanding in both psychology and the neurosciences may ultimately lead to greater benefits for athletes during practice and performance. As vehicles for exploring the arguments of a greater integration of psychology and neurosciences research, imagery and perception-action within the sport psychology and motor behaviour domains will serve as exemplars. Current neuroscience evidence will be discussed in relation to theoretical developments; the implications for sport scientists will be considered.

Behavior↗
PubMed2000

Serological prevalence of herpes simplex virus type 2 amongst GUM clinic attenders in a district general hospital setting.

Our objective was to determine the seroprevalence of herpes simplex virus (HSV) type 2 infection amongst genitourinary medicine (GUM) clinic attenders at a district general hospital using a commercially available enzyme immunoassay (EIA). In a prospective study, heterosexual patients attending the Department of GUM at Trafford General Hospital attending with a new clinical problem and having a blood sample taken for routine syphilis serology had the same sample tested for HSV type 2 antibodies. The prevalence of HSV type 2 seropositivity amongst participants was 9.9% (24/242) for men and 18.7% (46/246) for women. With respect to undiagnosed, asymptomatic infection the seroprevalence was 8.6% and 17% respectively. For those attenders locally resident the seroprevalence was 10.1% and 17.5% respectively, and undiagnosed, asymptomatic infection 8.5% and 17.1% respectively. Although seroprevalence figures in this study are lower than the only previous report in the UK, these results, nevertheless, show that seropositivity is not confined to large urban centres. Patients attending GUM clinics are likely to have high rates of undiagnosed HSV type 2 infection.

Antibodies, Viral↗
PubMed2000

Health risk in agricultural villages practicing wastewater irrigation in central Mexico: perspectives for protection.

9,435 individuals participated in a cross-sectional survey in the irrigation districts of the Mezquital Valley (central Mexico). Exposure groups were: 848 households irrigating with untreated wastewater, 544 households irrigating with the effluent from a series of interconnected reservoirs, and 928 households farming with natural rainfall. The unit of analysis was the individual, and the health outcomes included diarrhoeal diseases and Ascaris lumbricoides infection. Water quality was assessed using faecal coliforms (FC) and nematode eggs, as suggested by (WHO, 1989) for the safe use of wastewater in agriculture. Children from households irrigating with untreated wastewater (10(8) FC/100 mL and 135 nematode eggs/L) had a 33% higher risk of diarrhoeal diseases and a fivefold increase in risk of A. lumbricoides infection (OR = 5.71) compared to children from the control group, farming with rainfall. The risk of A. lumbricoides infection in older individuals was even higher (OR = 13.18). The final analysis showed that drinking unboiled water and cultivating vegetables crops were both associated with a higher risk of diarrheal diseases (OR = 1.45 and 2.00); individuals infected with A. lumbricoides infection came mostly from landless households with poorer dwellings and low standards of sanitation (OR = 2.20, 2.23, 1.72 and 1.43, respectively). These results are discussed in the context of health protection measures and policy recommendations.

Adolescent↗
PubMed1999

Newborns develop a Th1-type immune response to Mycobacterium bovis bacillus Calmette-Guérin vaccination.

Data obtained in animals indicate that neonatal immune responses are biased toward Th2. This could reduce the efficacy of vaccines against viral and mycobacterial diseases. The ability of human newborns to develop a Th1 immune response upon immunization has not been studied. Since the vaccine Mycobacterium bovis bacillus Calmette-Guérin (BCG) triggers a Th1-type response in adults, we investigated whether it induces a similar response in newborns and whether age at vaccination influences immunogenicity. We found that BCG vaccination at birth induces a memory Th1-type response of similar magnitude to that when given later in life. This study demonstrates that human newborns can be immunized against pathogens controlled by a Th1 immune response.

Antigens, Bacterial↗
PubMed1999

Elevated expression of FGF-2 does not cause prostate cancer progression in LNCaP cells.

BACKGROUND: Androgen-independent (AI) prostate cancer (CaP) resulting from progression of disease is untreatable. Such progression may relate to upregulation and autocrinicity of growth factor expression. We studied one candidate growth factor, basic fibroblast growth factor (FGF-2). METHODS: LNCaP cells made autocrine for FGF-2 by stable transfection with FGF-2 were examined for cancer progression, measured by 1) altered response to androgen, 2) ability to grow more quickly when cocultured with bone cells in vitro or to form tumors when coinoculated with bone cells in vivo, or 3) increase in metastatic ability. RESULTS: Stably transfected lines differed in FGF-2 protein expression. LNCaP-HF (high production of FGF-2) expressed more FGF-2 than LNCaP-LF (low production of FGF-2); controls were negative. In vitro, compared with LNCaPs, LNCaP-HF cells showed a slightly increased growth rate, reduced proliferation in response to androgen but not to estrogen or progesterone, and a decreased proliferative response to epidermal growth factor (EGF) and FGF-2. Although giving a slightly faster take rate, LNCaP-HF cells without Matrigel only formed small, fast-regressing tumors in male nude mice, and with Matrigel, did not differ from LNCaPs in growth rate or tumor size. No metastases occurred. No tumors grew in females. Mixed growth of FGF-2 transfectants with human fetal osteoblasts failed to cross-stimulate in vitro, or to allow tumor formation in vivo. CONCLUSIONS: Although FGF-2 is overexpressed in AI CaPs, our experiments show that upregulation of FGF-2 expression is not sufficient to cause androgen independence, tumorigenicity, or metastases production (i.e., prostate cancer progression) in LNCaP cells.

Animals↗
PubMed1999

Thymic microenvironment and NZB mice: the abnormal thymic microenvironment of New Zealand mice correlates with immunopathology.

There are distinct microenvironmental abnormalities of thymic architecture in several murine models of SLE defined using immunohistochemistry and a panel of mAb dissected at thymic epithelial markers. To address the issue of the relationship between the thymic microenvironment and autoimmunity, we studied backcross (NZB x NZW) F1 x NZW mice in which 50% of offspring develop nephritis associated with proteinuria and anti-DNA antibodies. We reasoned that if thymic abnormalities are associated with development of disease, the correlation of abnormalities with lupus-like disease in individual backcross mice will form the foundation for identification of the mechanisms involved. In parallel, we directed a genetic linkage analysis, using markers previously shown to be linked to nephritis and IgG autoantibody production, to determine if such loci were similarly associated with microenvironmental changes. Our data demonstrate that all (NZB x NZW) F1 x NZW backcross mice with disease have microenvironmental defects. Although the microenvironmental defects are not sufficient for development of autoimmune disease, the severity of thymic abnormalities correlates with titers of IgG autoantibodies to DNA and with proteinuria. Consistent with past studies of (NZB x NZW) F1 x NZW mice, genetic markers on proximal chromosome 17 (near MHC) and distal chromosome 4 showed trends for linkage with nephritis. Although the markers chosen only covered about 10-15% of the genome, the results demonstrated trends for linkage with thymic medullary abnormalities for loci on distal chromosome 4 and distal chromosome 1. We believe it will be important to define the biochemical nature of the molecules recognized by these mAbs to understand the relationships between thymic architecture and immunopathology.

Animals↗
PubMed1999

Timing a one-handed catch. I. Effects of telestereoscopic viewing.

The aim of this study was to examine the role of binocular and monocular information sources in specifying time-to-contact. More specifically, it was investigated whether the timing of the one-handed catch is consistent with a binocular tau-function strategy. Subjects (n=8) were required to time their grasp to catch a ball approaching with a constant spatial trajectory. The ball approached at three different constant velocities (1.5, 2.0 and 2.5 m/s). Vergence and disparity were manipulated through subjects wearing a telestereoscope to increase the effective interocular separation, under both binocular and monocular viewing. Subjects performed 24 trials in each of the four conditions. Subjects' started the opening of the hand earlier in the binocular telestereoscope condition when a ball approached with velocity of 1. 5 m/s. They then closed the hand earlier in the binocular telestereoscope condition at all ball approach velocities. There were no effects of telestereoscope on the timing of hand opening and closing under monocular viewing. This finding suggests the use of the binocular information in timing the grasp. However, there were effects of approach velocity under all conditions of monocular and binocular viewing. Subjects' closed the hand earlier as a function of increasing approach velocity. Together, the effects of the telestereoscope and approach velocity indicate that timing of the one-handed catch is not consistent with the use of a binocular "tau-function" variable. Rather, it is concluded that multiple sources of monocular and binocular information contribute to the regulation of timing.

Female↗
PubMed1999

Profit, payment and pharmaceutical practices: perspectives from hospitals in Bangkok.

Means by which to improve the quality of care offered in the private sector have received increasing interest. This paper considers the influences upon hospital physician prescribing practices. It presents data on drug management practices and prescribing patterns in a sample of private for-profit, private non-profit and public hospitals in Bangkok. Clear differences emerge in prescription patterns between the different groups of hospitals: public hospitals exhibit greater use of essential drugs and generic prescribing than either group of private hospital, and prescriptions at private for-profit hospitals tended to have more essential drugs and drugs prescribed by generic name than non-profit hospitals. Prescribing patterns in public hospitals are probably largely explained by national government policy on pharmaceutical procurement. In contrast, prescribing patterns in private for-profit hospitals appear heavily influenced by pressure upon management to contain costs, in circumstances where high drug costs cannot be passed on to purchasers. Hence hospital management have developed policies encouraging the use of generic drugs and essential drugs. These same financial pressures also explain some less desirable forms of behaviour in private for-profit hospitals such as prescribing courses of antibiotic treatment of extremely short duration. Possible measures which government may take to encourage appropriate prescribing within private hospitals are discussed.

Data Collection↗
PubMed1999

Manipulating visual informational constraints during practice enhances the acquisition of catching skill in children.

Previous motor learning studies examining the effects of practicing to catch one-handed under varying informational constraints on subsequent skill acquisition are equivocal, perhaps due to the use of relatively inexperienced adult participants. Ecological theory predicts that directing the learner's search for information in the perceptual-motor workspace can enhance skill acquisition. This study manipulated visual informational constraints on novice children (ages 9-10 years) learning to catch one-handed. A crossover transfer design was implemented in which one group acted as controls while two other groups practiced either without visual restrictions before transferring to full vision, or vice versa. The data indicated that learners forced to seek additional information sources under restricted viewing conditions demonstrated a greater positive, accumulative residual effect on acquiring a catching skill. The findings contradict current work on the specificity of practice hypothesis and suggest that varying visual informational constraints to encourage exploratory practice may represent a significant pedagogical approach to motor learning in sport.

Child↗
PubMed1999

Simple sample size calculation for cluster-randomized trials.

BACKGROUND: Cluster-randomized trials, in which health interventions are allocated randomly to intact clusters or communities rather than to individual subjects, are increasingly being used to evaluate disease control strategies both in industrialized and in developing countries. Sample size computations for such trials need to take into account between-cluster variation, but field epidemiologists find it difficult to obtain simple guidance on such procedures. METHODS: In this paper, we provide simple formulae for sample size determination for both unmatched and pair-matched trials. Outcomes considered include rates per person-year, proportions and means. For simplicity, formulae are expressed in terms of the coefficient of variation (SD/mean) of cluster rates, proportions or means. Guidance is also given on the estimation of this value, with or without the use of prior data on between-cluster variation. CASE STUDIES: The methods are illustrated using two case studies: an unmatched trial of the impact of impregnated bednets on child mortality in Kenya, and a pair-matched trial of improved sexually-transmitted disease (STD) treatment services for HIV prevention in Tanzania.

Child, Preschool↗
PubMed1999

Patient satisfaction in Bangkok: the impact of hospital ownership and patient payment status.

INTRODUCTION: Patient satisfaction with care received is an important dimension of evaluation that is examined only rarely in developing countries. Evidence about how satisfaction differs according to type of provider or patient payment status is extremely limited. OBJECTIVE: To (i) compare patient perceptions of quality of inpatient and outpatient care in hospitals of different ownership and (ii) explore how patient payment status affected patient perception of quality. METHODS: Inpatient and outpatient satisfaction surveys were implemented in nine purposively selected hospitals: three public, three private for-profit and three private non-profit. RESULTS: Clear and significant differences emerged in patient satisfaction between groups of hospitals with different ownership. Non-profit hospitals were most highly rated for both inpatient and outpatient care. For inpatient care public hospitals had higher levels of satisfaction amongst clientele than private for-profit hospitals. For example 76% of inpatients at public hospitals said they would recommend the facility to others compared with 59% of inpatients at private for-profit hospitals. This pattern was reversed for outpatient care, where public hospitals received lower ratings than private for-profit ones. Patients under the Social Security Scheme, who are paid for on a capitation basis, consistently gave lower ratings to certain aspects of outpatient care than other patients. For inpatient care, patterns by payment status were inconsistent and insignificant. CONCLUSIONS: The survey confirms, to some extent, the stereotypes about quality of care in hospitals of different ownership. The results on payment status are intriguing but warrant further research.

Adolescent↗