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Biomedical subjects

J Williams

Publications and source records attributed to J Williams.

At least 217 records · Page 12Linked to original sources
PubMed2000

A diagnostic EIA for detection of the prevalent SRSV strain in United Kingdom outbreaks of gastroenteritis.

Small round structured viruses (SRSVs) are the major cause of outbreaks of gastroenteritis in the UK. Diagnosis is problematic due to insensitive electron microscopy (EM) or technically demanding reverse transcription polymerase chain reaction (RT-PCR) techniques. We have studied outbreaks of non-bacterial gastroenteritis using an EIA based upon recombinant capsid protein from the currently prevalent circulating strain of SRSV (Lordsdale Genotype II) and compared its performance against EM and RT-PCR assays. Faecal specimens sent to the Bristol Public Health Laboratory for outbreak investigation from December 1996 to December 1997 were applied retrospectively to the SRSV EIA and results compared with the routine EM and RT-PCR that had been carried out prospectively. Overall, the three tests identified SRSVs in specimens from 70% of the outbreaks (213/305) investigated. Of the 213 total positive outbreaks, the EIA identified 71%, that compared favourably with EM (63%) and RT-PCR (84%). The Lordsdale Genotype II SRSV EIA provides a simple cost-effective assay that will for the first time make detection of currently circulating SRSV strains associated with UK outbreaks available to all routine laboratories. The EIA format makes the assay widely applicable to non-specialist laboratories, unlike the RT-PCR assay, and the improved sensitivity over EM will allow successful screening of UK outbreaks alongside commercial EIAs currently available for adenovirus, astrovirus and rotavirus. Furthermore, the assay will allow rapid identification of emerging SRSV strains.

Capsid↗
PubMed2000

Early deaths in childhood cancer.

BACKGROUND: Deaths prior to or shortly after the diagnosis of childhood cancer may reflect inadequacies in detection and appropriate referral for care. This study was performed to determine the extent of and factors associated with early death in childhood cancer. PROCEDURE: Patients with of primary cancer, aged <20 years at diagnosis, were identified from the SEER data (n = 23,470) from 1973 to 1995. Early deaths were defined as cases identified by 1) death certificate, 2) autopsy report, or 3) death within 1 month of initial diagnoses (n = 481). Cause of death was determined by ICD-8 and -9 codes. Age at diagnosis, year of diagnosis, morphology, site of disease, race, and gender were evaluated for association with early death. RESULTS: Age <1 year at diagnosis (6.2% early deaths), being diagnosed earlier in the observation period, and a diagnosis of a brain tumor, neuroblastoma, leukemia, or liver tumor were associated with increased early death. Gender and race were not associated with early death. Among the cases for whom the malignant diagnosis was made at the time of death (n = 119), the cause of death was nonmalignant for 36. For 22 of these cases the malignancy was an incidental finding and appeared not to contribute directly to the cause of death. Among these patients, 11 had neuroblastoma, 9 being <1 year of age. CONCLUSIONS: A decrease in the proportion of early deaths associated with childhood cancer has occurred during the past 2 decades. This decrease may reflect earlier diagnosis or improved imaging capabilities, surgical techniques, medical therapy, and supportive care. Awareness among pediatricians, general practitioners, and emergency physicians is warranted, with a focus on high-risk groups for early detection among childhood cancer patients.

Adolescent↗
PubMed2000

Plasma volume expansion for treatment of women with pre-eclampsia.

BACKGROUND: Plasma volume is reduced amongst women with pre-eclampsia. This association has led to the suggestion that expanding the plasma volume might improve maternal and uteroplacental circulation, and so potentially improve outcome for both the woman and her baby. OBJECTIVES: The aim of this review was to assess the effects of plasma volume expansion for the treatment of women with pre-eclampsia. SEARCH STRATEGY: The register of trials maintained by the Cochrane Pregnancy and Childbirth Group, and the Cochrane Controlled Trials Register Issue 1 1999 were searched for trials meeting the selection criteria. SELECTION CRITERIA: Randomised trials were included. Quasi-random designs were excluded. Participants were women with hypertension during pregnancy, with or without proteinuria. Women who were postpartum at trial entry were excluded. Interventions were any comparison of plasma volume expansion with no expansion, or of one plasma volume expander with another. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers. Discrepancies were resolved by discussion. There was no blinding of authorship or results. MAIN RESULTS: Three trials involving 61 women were included in this review. All compared a colloid solution with no plasma volume expansion. For every outcome reported, the confidence intervals are very wide and cross the no effect line. REVIEWER'S CONCLUSIONS: There is insufficient evidence for any reliable estimates of the effects of plasma volume expansion for women with pre-eclampsia.

Female↗
PubMed2000

Cognitive-behavioral stress management reduces distress and 24-hour urinary free cortisol output among symptomatic HIV-infected gay men.

BACKGROUND: Stress management interventions can reduce symptoms of distress as well as modulate certain immune system components in persons infected with human immunodeficiency virus (HIV). These effects may occur in parallel with reductions in hypothalamic-pituitary-adrenal (HPA) axis hormones such as cortisol, which has been related in other work to a down-regulation of immune system components relevant to HIV infection. The present study tested the effects of a multimodal cognitive-behavioral stress management (CBSM) intervention on 24-hour urinary free cortisol levels and distressed mood in symptomatic HIV+ gay men. METHODS: Symptomatic HIV-infected gay men who were randomized to either a 10-week group-based CBSM intervention or a 10-week wait-list period provided psychological responses and urine samples pre-post intervention. RESULTS: Of the 59 participants providing matched questionnaire data, men assigned to CBSM (n = 40) showed significantly lower posttreatment levels of self-reported depressed affect, anxiety, anger, and confusion than those in the wait-list control group (n = 19). Among the 47 men providing urine samples (34 CBSM, 13 controls), those assigned to CBSM revealed significantly less cortisol output as compared to controls. At the individual level, depressed mood decreases paralleled cortisol reductions over this period across the entire sample. CONCLUSION: A time-limited CBSM intervention reduced distress symptoms and urinary free cortisol output in symptomatic HIV+ gay men and greater reductions in some aspects of distress, especially depressed mood, paralleled greater decreases in cortisol over the intervention period. If persisting stressors and depressed mood contribute to chronic HPA axis activation in HIV-infected persons, then interventions such as CBSM, which teaches them to relax, alter cognitive appraisals, use new coping strategies, and access social support resources, may decrease distress and depressed mood and normalize HPA axis functioning.

Adult↗
PubMed2000

A comparison of optical coherence tomography and retinal nerve fiber layer photography for detection of nerve fiber layer damage in glaucoma.

PURPOSE: To compare optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness measurements with established methods for assessment of glaucomatous damage using RNFL photography and visual field testing. DESIGN: Cross-sectional study. PARTICIPANTS: Fifty-eight eyes of 58 healthy volunteer ocular hypertensive patients, glaucoma suspect patients, and glaucoma patients were included. METHODS: Optical coherence tomography 3.4-mm diameter circular scans were obtained within 3 months of RNFL photography and standard achromatic visual field testing. Three independent observers graded RNFL photographs using two standardized protocols. For each method, superior and inferior arcuate bundles were scored separately, and interobserver and intraobserver variation was measured. Standard achromatic visual field mean deviation in the superior and inferior hemifields was compared with RNFL damage as assessed by photography and OCT RNFL thickness measurements. MAIN OUTCOME MEASURES: Visual field mean deviation and severity of glaucomatous RNFL damage as assessed by photography. RESULTS: Optical coherence tomography RNFL thickness decreased with increasing RNFL damage as assessed by photography using both methods of photographic assessment. Standard achromatic perimetry mean deviation was significantly associated with OCT RNFL thickness (R(2) = 35%-43%) and RNFL photography severity score (R(2) = 18%-29%). CONCLUSIONS: These results suggest that the OCT shows promise for providing quantitative measures of RNFL thickness for diagnosing and monitoring glaucoma.

Adult↗
PubMed2000

Duplication of 1q in a child with down syndrome and myelodysplastic syndrome.

Cytogenetic analysis of bone marrow cells was performed on a 2-year-old African-American male with Down syndrome (DS) and myelodysplastic syndrome (MDS), specifically refractory anemia with excess blasts in transformation (RAEB-T). Chromosome analysis showed, in addition to the constitutional trisomy 21, a trisomy of chromosome 11 and a dup(1)(q23q31). This duplication of 1q is apparently a new chromosomal abnormality in a child with MDS. Partial trisomy of the long arm of chromosome 1 has been reported by several authors and appears to represent a nonrandom chromosomal anomaly in patients with MDS/acute myelogenous leukemia and DS.

Anemia, Refractory, with Excess of Blasts↗
PubMed2000

The last resort would be to go to the GP'. Understanding the perceptions and use of general practitioner services among people with HIV/AIDS.

In England and Wales, departments of Genito-Urinary Medicine have led the clinical response to HIV infection and AIDS (HIV/AIDS). They provide an open-access self-referral service on a basis of strict confidentiality. People with HIV/AIDS have been found to be reluctant to involve their general practitioner (GP) in their care. Previous research has not investigated their decisions about service use in the context of their broader strategies for coping with the multiple psychological and social challenges, which are posed by HIV/AIDS as a chronic, stigmatised condition. We report a depth-interview study of twenty people with HIV/AIDS in a low-prevalence nonmetropolitan urban area of England. Their health care choices were products of complex judgements. Five concerns predominated: expertise, security, rights to care, confidentiality and the maintenance of normality. Transfer to GP care signified a transition from essential wellness to essential illness and represented a loss of biographical continuity. Their other concerns express problems of information management, which are universal features of stigmatising conditions. These may be heightened in the case of locally provided services, where any leakage of discrediting information is likely to impact directly on everyday life. These concerns should be understood and respected in policy initiatives to develop services.

Confidentiality↗
PubMed2000

The nature of the effect of female gonadal hormone replacement therapy on cognitive function in post-menopausal women: a meta-analysis.

We reviewed epidemiological and experimental studies of female gonadal hormone replacement therapy (HRT) on cognitive function in post-menopausal women and carried out meta-analyses. In healthy ageing women, HRT has small and inconsistent effects that include enhancement of verbal memory, abstract reasoning and information processing. Epidemiological studies show larger effects than experimental studies, which is not related to sample size. Important confounds may be that women who start using HRT are healthier than women who do not. Also, controlling for socio-economic status diminishes the effect of HRT. The effects of HRT may depend on the age and type of menopause and the therapeutic intervention used, with the most widely used drug, Premarin, having least effect. However, the effects are independent of mood and climacteric symptom alleviation. There is a paucity of experimental studies that include healthy elderly women. The evidence for an estrogen deficiency in women with dementia and cognitive dysfunction is inconsistent. Nevertheless, epidemiological studies suggest that HRT protects against the development of clinically diagnosed Alzheimer's disease. However, poor recall of HRT use by patients and altered physician behaviour may have confounded the effects. Surprisingly, both healthy and demented women with low education seem to benefit most from HRT. Three recent controlled experimental studies using Premarin showed no effects of HRT in preventing further cognitive decline in women who already have Alzheimer's disease. Duration of treatment seems to play an important role, with beneficial effects declining-and even reversing-with longer treatment in women with Alzheimer's disease.Future research should further investigate the cognitive effect of different HRT preparations, serum estrogen levels, and the interactions of HRT with age, menopausal status and existing protective (e.g. education) and risk factors (e.g. smoking and apolipoprotein E genotype) for cognitive decline and Alzheimer's disease.

Age Factors↗
PubMed2000

A chicken leptin-specific radioimmunoassay.

Recombinant chicken leptin was used to produce an antiserum in order to develop a specific and sensitive radioimmunoassay (RIA) for chicken leptin in plasma and serum. We have used either murine or chicken leptin as tracer and competition curves were performed using recombinant chicken leptin. Variations in leptin plasma levels in different chicken strains and various nutritional states were correlated with the physiological status. Leptin plasma concentrations were regulated by the nutritional state with higher levels in the fed state as compared to the fasted state (3.36 +/- 0. 13 versus 2.78 +/- 0.11 ng/ml) and being dependent upon the age. Higher leptin levels were found in 22 week-old as compared to 15 week-old layer chickens (2.709 +/- 0.172 versus 1.478 +/- 0.102 ng/ml). We have also shown that the multispecies leptin RIA kit (LINCO Inc.) underestimated leptinemia compared to the chicken leptin- specific RIA reported here. In conclusion the RIA developed in the present study is specific to the chicken and thus may be considered as powerful tool for investigating the physiological significance of leptin in chickens.

Animals↗
PubMed2000

Reliability of adolescents' self-report of recent recreational injury.

PURPOSE: To assess the reliability of adolescents' self-report of recent recreational injury. METHOD: Identical written questionnaires were administered twice in a 3-week period to 75 randomly selected adolescents (aged 11-12 years and 15-16 years) in state primary and secondary schools in South Australia, Australia. The questionnaires sought information on injury sustained in the previous week. Parents of 60 of the adolescents were contacted in the same week as one of the questionnaire administrations, to verify their adolescent's most recent injury self-report. Intraclass and Pearson correlation coefficients provided evidence of agreement between responses, and stability of measure. RESULTS: There was high stability and good agreement between the parent and adolescent responses provided in the same week, suggesting that adolescents accurately reported recent recreational injury. The poor stability and low agreement between repeated adolescent responses over the 3-week period indicated not poor recall, but the changing nature of mostly minor recreational injury. These findings suggest that the nature of the injury reported in the first questionnaire had changed by the time of the second questionnaire administration, and that this was accurately reported. CONCLUSION: Confidence can be placed in adolescents' self-reports of recreational injury in the preceding week.

Adolescent↗
PubMed2000

Prevalence of adolescent injury from recreational exercise: an Australian perspective.

PURPOSE: To report the prevalence of recent adolescent recreational and sporting activities and associated injury. METHODS: Data were collected during three school terms in 1997 using a validated questionnaire administered once only to 3538 girls and boys aged 11-12 years and 15-16 years. These students comprised 97.5% of the students in these age ranges in randomly selected state and private schools in the Adelaide metropolitan area (South Australia). Participants identified up to three recreational and/or sporting activities in which they had participated in the previous week. Data were collected on the nature and extent of participation, and on associated injuries. Participation and injury reports were summarized descriptively in gender strata in the two adolescent age groups and stratum specific odds ratios were used to explore injury risk. RESULTS: Subjects reported participating in 8997 sporting and/or recreational activities in the preceding week (an average of 2.5 participations per student). Over 140 sports and recreational pursuits were represented, incorporating organized and nonorganized activities undertaken in teams, social groups, or alone. Approximately 25% of adolescents reported at least one recreational injury. Injuries were mostly minor, reflecting soft tissue trauma and skin abrasions. Organized group sport incurred the highest risk of injury. There were marked gender and year level differences in injury risk in a number of common activities. CONCLUSIONS: These findings support the need for ongoing education regarding injury prevention and management.

Adolescent↗
PubMed2000

Irradiation for intimal hyperplasia: implications for peripheral arterial bypass.

Irradiation has been shown to inhibit postangioplasty intimal hyperplasia ("restenosis") in unbranched tubes. It seems likely that irradiation will similarly be able to inhibit intimal hyperplasia after a surgical anastomosis at a biochemical and cellular level, but whether it will produce a clinically relevant or even clinically detectable difference is unproved. One possibility is that no clinical effect may occur; the search for a "cure" for intimal hyperplasia has been long and, as yet, unsuccessful. On the other hand, if a strong effect without insurmountable logistical problems could be produced, one major cause of bypass graft failure would be preventable. Not only would the incidence of late graft occlusion, need for reoperation, and limb loss be reduced, but, if patency of prosthetics could be sufficiently improved, the initial operation could be made much easier, faster, and perhaps safer.

Angioplasty, Balloon↗
PubMed2000

Glucose-insulin relationships and thyroid status of cockerels selected for high or low residual food consumption.

The plasma glucose-insulin relationships and thyroid status were investigated in two lines of adult cockerels divergently selected for high (R+) or low (R-) residual food consumption (RFC). For a given body weight, R+ birds had a 74% higher food intake than R- birds. Plasma glucose concentrations were significantly lower in the R+ line compared with the R- when fasted, whereas R+ birds exhibited a significantly lower plasma insulin concentration than R- birds either in fed or fasted state. After an overnight fast, R+ birds also exhibited a higher sensitivity to exogenous insulin in view of its more pronounced hypoglycaemic effect. After an oral glucose load, the glucose disposal of R+ cockerels was faster despite lower glucose-induced plasma insulin concentration. Whilst plasma triacylglycerol concentrations were lower in the R+ line when fed, plasma non-esterified fatty acid concentrations were higher in fasted R+ than R- cockerels (684 v. 522 mumol/l). Higher plasma triiodothyronine concentrations were observed in fed R+ compared with R- birds (3.0 v. 2.1 nmol/l respectively). The higher plasma concentrations of triiodothyronine associated with lower concentrations of insulin could account for the leanness and the elevated diet-induced thermogenesis previously observed in the R+ line.

Animal Feed↗
PubMed2000

Measurement of fidelity in psychiatric rehabilitation.

Until recently, most psychiatric rehabilitation models have been poorly defined and few have had systematic methods for measuring their implementation. We review the historical roots for the development of fidelity measures and describe recent applications in both research and practice.

Humans↗
PubMed2000

Cholesterol standardized plasma vitamin E levels are reduced in patients with severe angina pectoris.

Vitamin E, the major lipid soluble plasma antioxidant, has been reported to be reduced in patients with coronary atherosclerosis. We have measured the levels of plasma alpha-tocopherol (the predominant form of plasma vitamin E) in 128 patients with different reported degrees of angina. Patients with mild to moderate angina (grades I or II (CSS score)) (n = 64), and patients with severe angina (grades III and IV) (n = 64) were recruited from Cardiology Clinics in the U. K. Healthy controls (n = 33) and patients with hyperlipidaemia (n = 28) were also recruited. The groups of patients with angina did not differ significantly for mean age (58 +/- 1.0 years vs. 59 +/- 1.0 years, respectively); sex distribution (the M:F ratio was 48 : 16 and 46 : 18 for the respective groups); or prevalence of smoking (12% vs. 9%), or hypertension (19% vs. 33%). Total cholesterol levels were higher in the group with severe angina (5.9 +/- 0.16 mmol/l vs. 5.3 +/- 0.13 mmol/l P < 0.05). Absolute levels of plasma vitamin E were not significantly different between the angina subgroups (12.9 +/- 0.40 mg/l for the mild-moderate angina group vs. 12.5 +/- 0.51 mg/l for the severely affected group), but were positively correlated with plasma cholesterol concentrations in each case (P < 0.001). The ratio between plasma vitamin E: total cholesterol was significantly lower in the patients with severe angina (mean 2.20 +/- 0.09 mg/mmol) vs. a mean value of 2.46 +/- 0. 08 mg/m mol in the mildly affected group (P < 0.05). The plasma vitamin E: total cholesterol ratio in patients with severe angina was also significantly lower (P < 0.05) compared to either healthy controls with comparable total cholesterol levels (n = 33), or hypercholesterolaemic subjects (n = 28) without symptomatic coronary disease (mean ratios were 2.69 +/- 0.40 mg/mmol and 2.74 +/- 0.68 mg/mmol, respectively). Vitamin E has previously been demonstrated to protect endothelial function in the presence of hypercholesterolaemia, possibly by preserving nitric oxide bio-activity. It also inhibits LDL oxidation. Hence, a high plasma vitamin E: total cholesterol ratio may be associated with an amelioration of angina.

Adult↗
PubMed2000

Smoldering HTLV-1-induced T-cell lymphoma localized within the skin; a radiation-resistant tumor.

BACKGROUND: Human T-cell lymphotrophic virus type 1 (HTLV-1)-induced lymphoproliferative disease occurs in approximately 3-5% of people in endemic areas who have been HTLV-1 positive for decades. Lymphoproliferative disease may present as four subtypes, including an acute adult T-cell leukemia/lymphoma (ATLL), an aggressive HTLV-1 lymphoma, chronic ATLL, and smoldering ATLL. MATERIALS AND METHODS: A 72-year-old HTLV-1+ Haitian woman presented with a 2-year history of a cutaneous eruption localized to the right arm. The eruption had evolved into multinodular lesions over the past 6-7 months. Peripheral blood and cutaneous biopsy specimens were evaluated. Immunohistochemical studies for lymphoid markers were performed on the cutaneous biopsy material, and polymerase chain reaction (PCR) and Southern blot assay were evaluated for the presence and integration of HTLV-1 within the genome. RESULTS: The biopsy specimen showed a pleomorphic T-cell infiltrate with epidermotrophism, and an immunohistochemical phenotype showing CD3+, CD4+, CD8-, CD25, CD30-, HLDA-DR+ cells. PCR and Southern blot assay evaluation showed a single clonal integration of HTLV-1 provirus within a monoclonal tumor cell population. The patient had no abnormal lymphoid forms on peripheral smear at presentation, and no evidence of other organ involvement. CONCLUSIONS: Smoldering HTLV-1-induced lymphoma is uncommon even in endemic areas. In previously reported cases, the smoldering variant was accompanied by abnormal forms in the peripheral blood and/or by other signs of systemic disease. This case illustrates that smoldering disease may be localized to the skin with no detected morphologic abnormalities on peripheral smear.

Aged↗
PubMed2000

Characterisation of a DNA sequence element that directs Dictyostelium stalk cell-specific gene expression.

The ecmB gene of Dictyostelium is expressed at culmination both in the prestalk cells that enter the stalk tube and in ancillary stalk cell structures such as the basal disc. Stalk tube-specific expression is regulated by sequence elements within the cap-site proximal part of the promoter, the stalk tube (ST) promoter region. Dd-STATa, a member of the STAT transcription factor family, binds to elements present in the ST promoter-region and represses transcription prior to entry into the stalk tube. We have characterised an activatory DNA sequence element, that lies distal to the repressor elements and that is both necessary and sufficient for expression within the stalk tube. We have mapped this activator to a 28 nucleotide region (the 28-mer) within which we have identified a GA-containing sequence element that is required for efficient gene transcription. The Dd-STATa protein binds to the 28-mer in an in vitro binding assay, and binding is dependent upon the GA-containing sequence. However, the ecmB gene is expressed in a Dd-STATa null mutant, therefore Dd-STATa cannot be responsible for activating the 28-mer in vivo. Instead, we identified a distinct 28-mer binding activity in nuclear extracts from the Dd-STATa null mutant, the activity of this GA binding activity being largely masked in wild type extracts by the high affinity binding of the Dd-STATa protein. We suggest, that in addition to the long range repression exerted by binding to the two known repressor sites, Dd-STATa inhibits transcription by direct competition with this putative activator for binding to the GA sequence.

Animals↗