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S Thomas

Publications and source records attributed to S Thomas.

At least 73 records · Page 4Linked to original sources
PubMed2004

Surface enhanced Raman scattering of benzotriazole: a molecular orientational study.

Surface enhanced Raman scattering of benzotriazole in aqueous silver sol at pH approximately 9 has been investigated. The spectra of the molecule at various concentrations were recorded and the maximum enhancement was observed with a 10(-5) M solution. From the comparison of the surface enhanced Raman spectra with the conventional Raman spectra and applying "surface selection rule", it is inferred that the molecular ion interacts with the silver sol via the nitrogen atoms of the benzotriazole ring and the molecule assumes a near "end-on" orientation.

Argon↗
PubMed2004

Clinical outcomes of patients with impaired left ventricular ejection fraction undergoing autologous bone marrow transplantation: can we safely transplant patients with impaired ejection fraction?

Experience with autologous bone marrow transplantation (ABMT) in patients with impaired left ventricular ejection fraction (LVEF) or heart failure (HF) is limited. We identified 308 consecutive patients who underwent ABMT for Hodgkin's or non-Hodgkin's lymphoma at our institution (1996-2003). Patient characteristics, clinical course and overall survival were compared between patients with preserved ( > or = 50%) or impaired ( < 50%) LVEF. Of the 308 patients identified, 20 had baseline impaired LVEF (four with LVEF < or = 40%, all NYHA class I-II HF). None of the patients with post-ABMT echocardiogram had worsened LVEF (n = 7). Among the 20 patients with impaired LVEF, four patients had reversible cardiac complications post-ABMT (including worsening HF). The two deaths observed in the impaired LVEF group were both due to noncardiac causes. The 5-year survival was similar between patients with preserved and impaired LVEF (P = 0.43). Careful selection of patients with stable, mild-to-moderate HF and impaired LVEF for ABMT can achieve similar long-term survival. As medical care for HF and ABMT improves, the exclusion criteria for ABMT with regard to HF and impaired LVEF should be re-examined.

Adult↗
PubMed2004

Ocular manifestations of mosaic trisomy 22: a case report and review of the literature.

Mosaic trisomy 22 is rare, but can be compatible with prolonged life. Patients with mosaic trisomy 22 usually present with intrauterine growth retardation, mental retardation, failure to thrive, and craniofacial asymmetry. We report the case of a five-year-old boy who had a birth weight of 3.8 kg and normal developmental milestones. He presented with unilateral ocular manifestations of ptosis, double elevator palsy, high myopia, and choroidal coloboma involving the macula. Cytogenetic evaluation showed a low level of trisomy 22 in peripheral blood lymphocytes (1 in 100) and in cultured fibroblasts from a conjunctival biopsy of the affected eye (1 in 60). Our case demonstrates the value of chromosomal analysis of the tissues involved rather than just karyotyping of the blood lymphocytes to detect mosaicism in patients with localised and unilateral congenital malformations.

Abnormalities, Multiple↗
PubMed2004

Diabetes care in Dutch general practice: differences between Turkish immigrants and Dutch patients.

AIM: To compare the adherence to clinical guidelines by GPs as registered and glycaemic control in Turkish and Dutch type 2 diabetes patients. DESIGN: A retrospective cohort study. Search of general practice medical records for diabetes-related variables of Turkish and Dutch diabetes patients, stratified for age and gender. SETTING: Seventeen general practices (37 GPs) in the inner city of Rotterdam. SUBJECTS: 196 type 2 diabetes patients (106 Turkish and 90 Dutch), known with diabetes for at least 18 months, were followed for two years during the 1992-1997 period. MAIN OUTCOME MEASURES: 1) Level of care as registered in the medical records based on eight quantifiable criteria derived from the national guidelines for GPs; and 2) glycaemic control (fasting and non-fasting blood glucose levels). RESULTS: Turkish patients visited the GP for periodic control more often than Dutch patients. The other seven criteria were followed in an equal number of Turkish and Dutch patients. Turkish patients had a higher mean non-fasting plasma glucose level (12.9 mmol/l) than Dutch patients (10.8) (p=0.001) during the two-year follow-up. CONCLUSIONS: Although adherence to clinical guidelines as registered in Turkish and Dutch type 2 diabetes patients is comparable, Turkish patients have higher mean non-fasting plasma glucose level than their Dutch counterparts.

Adult↗
PubMed2004

'I was running away from death'- the pre-flight experiences of unaccompanied asylum seeking children in the UK.

OBJECTIVE: To collect information about the pre-flight experiences of unaccompanied asylum seeking children (UASC) in the UK to increase the understanding of support needed on arrival in the UK. METHODS: Retrospective social services case file and legal statement review and semi-structured in-depth interviews with 100 UASC. RESULTS: Nearly half of all UASC have experienced separation from or loss of parents and/or family members (47%), and a further 41% had personally experienced or witnessed violence. Sexual violence (such as rape) was reported by 24% of African girls. Many children reported complex journeys to the UK. CONCLUSIONS: UASC arrive in the UK with a variety of potentially traumatic experiences. Whilst research is starting to identify some of the experiences of UASC, further culturally appropriate research is needed to identify their health and social needs after arrival. Further research will help to identify the specific experiences of UASC, indicating where services should be improved to deal with their complex and diverse needs.

Adolescent↗
PubMed2004

A systematic review of case-control studies of human papillomavirus infection in laryngeal squamous cell carcinoma.

A role for human papillomavirus (HPV) has been suggested in laryngeal squamous cell carcinoma (LSCC). In order to quantitate the available evidence, we reviewed studies examining the risk of laryngeal cancer-associated HPV. PubMed was searched for case-control studies conducted worldwide and published in any language since 1966. Relevant papers were hand-searched and cross-referenced. Six studies met the inclusion criteria. The studies are heterogeneous in the methods used to harvest tissue samples and techniques for detecting the virus within the tissue. HPV-16 positivity among cases ranged from 2.7% to 46.9% and 0-5.7% among controls. Two studies showed a significantly increased risk of LSCC if HPV-16 was present (OR 18.5, 95% CI 2.2-154.8, OR 2.6, 95% CI 1.1-6.0). An increased risk was also observed for glottic versus supraglottic cancer in one study (OR 9.69, 95% CI 1.47-64.04). The direction of effect is towards an increase in risk of LSCC in people with evidence of HPV-16 infection. There is marked heterogeneity in the methods used to detect the virus and frequency with which it is detected. An adequately powered study using a reliable detection technique is required to confirm and quantify this risk and to examine effect modification.

Carcinoma, Squamous Cell↗
PubMed2004

Determinants of long-term highly active antiretroviral treatment efficacy.

OBJECTIVES: Predictors of the efficacy of highly active antiretroviral therapy (HAART) have been investigated in several studies. To increase current knowledge, the study aimed to acquire comprehensive data over an extended observation time, to obtain information on possible performance differences among individual drugs, and to identify factors with influence on the initial response to a HAART regimen and the sustainability of the response. METHODS: The data were obtained from a prospective, single University Medical School HIV cohort. Clinical, laboratory, and treatment parameters for 475 patients were collected over 4.5 years. HAART efficacy was determined by analysis of variance and multivariate survival analysis. RESULTS: The overall initial complete response (CR) (<500 HIV-1 RNA copies/mL) was 76.3%. Use of indinavir [odds ratio (OR)=2.747, P=0.0009] and the number of new nucleoside reverse transcriptase inhibitors (NRTIs) (OR=1.862, P=0.0017) were positively associated with CR, while initial peripheral blood HIV RNA concentration (OR=0.383, P<0.0001), use of saquinavir hard gel capsules (OR=0.531, P=0.0302), the number of successive HAART regimens (OR=0.631, P<0.0001), and the number of previously used NRTIs (OR=0.728, P=0.0081) were negatively associated with CR. Sustainability of CR was positively correlated with use of indinavir [hazard ratio of relapse (HR)=0.255, P<0.0001] and haemoglobin levels (HR=0.873, P=0.0124), but negatively correlated with initial HIV RNA concentration (HR=1.273, P=0.0003) and the number of previously used NRTIs (HR=1.587, P<0.0001). A higher number of consecutive HAART regimens was associated with a markedly reduced CR, but with only a slightly higher risk of relapse. CONCLUSIONS: The initial response to HAART, as well as long-term efficacy, depends strongly on a few fundamental parameters that can easily be assessed in a clinical setting. There is a need for effective suppression of HIV replication over decades, and these factors should be considered early in treatment planning to identify patients with an unfavourable profile of risk factors for treatment failure.

Antiretroviral Therapy, Highly Active↗
PubMed2004

Invasive pneumococcal disease in Jamaican children.

A 5-year retrospective review of cases of invasive pneumococcal disease admitted to the Bustamante Hospital for Children, Jamaica was conducted. A total of 111 cases were identified. The estimated incidence of invasive pneumococcal disease in Kingston and St Andrew was 21/100,000 children under the age of 10 years. The majority of cases (76%) were in the under-2-years age group. All four deaths were of infants. Pre-existing medical conditions included sickle cell disease, HIV and undernutrition. The rate of resistance to penicillin was 13.8%. Meningitis accounted for three of the four deaths identified and poor outcome was identified in 28% of cases of meningitis. We conclude that invasive pneumococcal disease causes significant morbidity and mortality in young Jamaican children. Strategies directed at preventing HIV infection and malnutrition and improving the care of children with sickle cell disease and HIV infection would significantly reduce disease incidence.

Anemia, Sickle Cell↗
PubMed2004

Influenza vaccination in asthmatic children: effects on quality of life and symptoms.

This study aimed to detect the effect of influenza vaccination on quality of life, symptomatology and spirometry in asthmatic children. A randomised double-blind placebo-controlled trial in 696 (296 in 1999-2000 and 400 in 2000-2001) asthmatic children aged 6-18 yrs, which were vaccinated with either vaccine or placebo, was performed. Children participated for only one influenza season. They recorded symptoms in a diary and reported when symptom scores reached a predefined severity level. If this occurred research nurses visited them twice, first to take a pharyngeal swab and spirometry, and a week later to assess quality of life over the past illness week. Compared with placebo, vaccination improved health-related quality of life in the weeks of illness related to influenza-positive swabs. However, no effect was found for respiratory symptoms recorded in the diaries during those weeks. Similarly, no differences were found for quality of life in all weeks of illness or for respiratory symptoms throughout the seasons. Influenza vaccination was found to have a moderately beneficial effect on quality of life in influenza-positive weeks of illness in children with asthma.

Adolescent↗
PubMed2004

A systematic review and economic evaluation of magnetic resonance cholangiopancreatography compared with diagnostic endoscopic retrograde cholangiopancreatography.

OBJECTIVES: To compare the clinical and cost-effectiveness of magnetic resonance cholangiopancreatography (MRCP) with diagnostic endoscopic retrograde cholangiopancreatography (ERCP) for the investigation of biliary obstruction. DATA SOURCES: Electronic bibliographic databases, the reference lists of relevant articles and various health services research-related resources. REVIEW METHODS: The data sources were searched and selected studies were assessed using quality criteria. In total, 28 prospective diagnostic studies were identified reporting several suspected conditions plus one of patient satisfaction. Analyses were then performed to establish sensitivities, specificities, likelihood ratios and confidence intervals. The relative cost-effectiveness of adopting MRCP scanning in the investigation of the biliary tree was undertaken using a probabilistic economic model. RESULTS: The median sensitivity for choledocholithiasis (13 studies) was 93% and the median specificity 94%. The median likelihood ratio for a positive value was 15.75 and for a negative value 0.08. Reported sensitivities for malignancy were somewhat lower, ranging from 81 to 86%, and specificities ranged from 92 to 100%. There was some evidence that MRCP is an accurate diagnostic test in comparison to ERCP, although the quality of studies was moderate. Claustrophobia prevented at least some patients from having MRCP in ten of the 28 studies. The other 18 studies did not mention claustrophobia. The probability of avoiding unnecessary diagnostic ERCP is estimated at 30%. These patients could avoid the unnecessary risk of complications and death associated with diagnostic ERCP, and substantial cost saving would be gained. The overall expected cost saving associated with MRCP is GBP149; the overall expected gain in quality-adjusted life-year is estimated at 0.011. CONCLUSIONS: There is some evidence that MRCP is an accurate investigation compared with diagnostic ERCP, although the values for malignancy compared with choledocholithiasis were somewhat lower. The quality of studies was moderate. The limited evidence on patient satisfaction showed that patients preferred MRCP to diagnostic ERCP. The estimated clinical and economic impacts of diagnostic MRCP versus diagnostic ERCP are very favourable. The baseline estimate is that MRCP may both reduce cost and result in improved quality of life outcomes compared with diagnostic ERCP. Further research is suggested to compare MRCP and diagnostic ERCP with final diagnosis and also with the full range of target conditions; to examine patient satisfaction and ways of reducing problems with claustrophobia; to look at protocols to help identify who could most benefit from MRCP or ERCP; to assess the relative need and urgency of patient access to magnetic resonance imaging services, and also to determine how demand would affect availability and potential cost savings.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed2003

Sensitive detection of GM1 lipid rafts and TCR partitioning in the T cell membrane.

The cholesterol-rich lipid rafts on T cell membrane play important role in the formation of T cell receptor (TCR) signalosome upon receptor ligation. Analytical studies on the kinetics of lipid rafts formation and recruitment of protein receptors to lipid rafts are still limited by the use of a large number of cells. Herein, we describe a strategy for detecting fine alterations in the amount and distribution of glycosphingolipid (GM1) lipid rafts, and in the formation of GM1-TCR complexes in detergent-insoluble and -soluble compartments of the T cell membrane from a relative low number of cells. Using this strategy, we found that the GM1 moiety was physically associated with TCR in both detergent-insoluble and -soluble fractions. Shortly after ligation of CD3/TCR complex with a soluble CD3- epsilon mAb, the TCR was found mainly in the detergent-soluble fraction of the T cell membrane.

Animals↗
PubMed2003

Inhaled insulin in diabetes mellitus.

BACKGROUND: Insulin therapy often relies on multiple daily injections of insulin. However this is a considerable burden to many people with diabetes and adherence to such an insulin regimen can be difficult to maintain, hence compromising optimal glycaemic control. Also, short acting injected insulin is absorbed more slowly than insulin released by the normal pancreas in response to a meal. Inhaled insulin has the potential to reduce the number of injections to perhaps one long-acting insulin per day, and provide a closer match to the natural state, by more rapid absorption from the lung. OBJECTIVES: To compare the efficacy, adverse effects and patient acceptability of inhaled versus injected insulin. SEARCH STRATEGY: A sensitive search strategy for randomised controlled or cross-over trials was combined with key terms for inhaled insulins. Databases searched were: The Cochrane Library, MEDLINE, PubMed, EMBASE, Science Citation Index, BIOSIS, Web of Science Proceedings, National Research Register UK, Current Controlled Trials, ClinicalTrials.gov, Conference Papers Index, LexisNexis, and web sites of the ADA and EASD were searched for recent meeting abstracts. Reference lists and journals were handsearched. There were no language restrictions on searching. Manufacturers of inhaled insulin were also contacted. Date of last search October 2002. SELECTION CRITERIA: Only randomised controlled trials with parallel groups or controlled cross-over trials, including type 1 or type 2 diabetic patients of any age treated with insulin, were considered eligible. The minimum trial duration considered was 10 weeks, as this is the time taken for glycated haemoglobin to reliably reflect changes in glycaemic control. DATA COLLECTION AND ANALYSIS: Trial selection and evaluation of study quality was performed independently by two reviewers. The quality of reporting of each trial was assessed according to a modification of the criteria outlined in Centre for Reviews and Dissemination (CRD) Report 4, Spitzer; and Jadad. MAIN RESULTS: Six randomised controlled trials were found and the overall number of participants was 1191. Three trials included patients with type 1 diabetes and three with type 2 diabetes. Three trials had a duration of 24 weeks, and three of 12 weeks. All were open label. There was insufficient information to determine the study quality. Results for HbA1c were similar for all trials, in that all showed comparable glycaemic control for inhaled insulin compared to an entirely subcutaneous regimen. All trials that reported patient satisfaction and quality of life showed that these were significantly greater in the inhaled insulin group. Overall there was no difference in total hypoglycaemic episodes between the groups, but one trial showed a statistically significant increase in severe hypoglycaemic episodes for the inhaled insulin group. No adverse pulmonary effects were observed in any of the studies, but longer follow-up will be required to be sure that there are no adverse side-effects. Cavets include: few studies published in full (so quality could not be assessed), and only two studies used the same basal regimen in both the inhaled and injected groups. REVIEWER'S CONCLUSIONS: Inhaled insulin taken before meals, in conjunction with an injected basal insulin, has been shown to maintain glycaemic control comparable to that of patients taking multiple daily injections. The key benefit appears to be that patient satisfaction and quality of life are significantly improved, presumably due to the reduced number of daily injections required. However, the patient satisfaction data is based on five trials, of which only two have been published in full; also the three trials containing quality of life data are all only published in abstract form at present. In addition, longer term pulmonary safety data are still needed. Also, the lower bioavailability, and hence higher doses of inhaled insulin required, may make it less cost-effective than injected insulin.

Administration, Inhalation↗
PubMed2003

Routine hospital admission versus out-patient or home care in children at diagnosis of type 1 diabetes mellitus.

BACKGROUND: In many places, children newly diagnosed with type 1 diabetes mellitus are admitted to hospital for metabolic stabilisation and training, even if they are not acutely ill. Out-patient or home based management of these children could avoid the stress associated with a hospital stay, could provide a more natural learning environment for the child and its family, and might reduce costs for both the health care system and the families. OBJECTIVES: To assess the effects of routine hospital admission compared to out-patient or home-based management in children newly diagnosed with type 1 diabetes who are not acutely ill, on metabolic control, wellbeing and self-efficacy of the patient and his/her family. SEARCH STRATEGY: We searched the Cochrane Library (including the Cochrane Controlled Trials Register), Medline, Embase, Cinahl, and the British Nursing Index. Additionally, we searched reference lists of relevant studies identified and contacted one of the trialists about further studies. Date of latest search: February 2003. SELECTION CRITERIA: Comparative studies of initial hospitalisation compared to home-based and/or out-patient management in children with newly diagnosed type 1 diabetes. DATA COLLECTION AND ANALYSIS: Studies were independently selected by two reviewers. Data extraction and quality assessment of trials were done independently by two reviewers. Any differences in opinion were resolved by discussion. Authors of included studies were contacted for missing information. Results were summarised descriptively, using tables and text. MAIN RESULTS: Six studies were included in the review, including a total of 237 children in the out-patient/home group. Two studies were randomised controlled trials, three were retrospective cohort studies, and one was a prospective cohort study. Except for one randomised controlled trial that included children in the intervention group who were initially hospitalised for a brief period, studies were of low quality. The one high quality trial identified suggested that home-based management of children with newly diagnosed type 1 diabetes may lead to slightly improved long term metabolic control (at two and three years follow-up). No differences between comparison groups were found in any of the psychosocial and behavioural variables assessed or in rates of acute diabetic complications within two years. Parental costs were found to be decreased, while health system costs were increased, leaving total social costs virtually unchanged. None of the other studies assessing metabolic control found a difference between the comparison groups. There seemed to be no differences in hospitalisations or acute diabetic complications between the out-patient/home groups and the hospital groups. Results with respect to psychosocial and behavioural variables were inconclusive, with only one study finding significant results on some selected subscales of tests used. In another study, the out-patient/home group did significantly better on the assessments of treatment adherence, familial relationship and sociability, but upon further analysis this only seemed to apply to selected socioeconomic subgroups, with no clear explanations offered. REVIEWER'S CONCLUSIONS: Due to the generally low quality or limited applicability of the studies identified, the results of this review are inconclusive. On the whole, the data seem to suggest that out-patient/home management of type 1 diabetes in children at diagnosis does not lead to any disadvantages in terms of metabolic control, acute diabetic complications and hospitalisations, psychosocial variables and behaviour, or total costs. Primary research, ideally a high quality randomised controlled trial, is required.

Adolescent↗
PubMed2003

Heat preconditioning prevents oxidative stress-induced damage in the intestine and lung following surgical manipulation.

BACKGROUND: The intestine is increasingly recognized as a primary effector of distant organ damage, such as lung, following abdominal surgery. Surgical manipulation of the intestine generates oxygen free radicals resulting in mucosal damage. Heat preconditioning has been proposed to prevent various stress-induced alterations in cells and tissues, including oxidative stress. This study examined the effect of heat preconditioning on oxidative stress-induced damage to the intestine and lung, following surgical manipulation. METHODS: Control rats and rats pretreated with heat were subjected to surgical manipulation by opening the abdominal wall and handling the intestine as done during laparotomy. Intestine and lung were assessed for damage by histology and markers of oxidative stress. RESULTS: Surgical manipulation resulted in ultrastructural changes in the intestine. Biochemical alterations in the enterocytes were evident, with increased xanthine oxidase activity resulting in production of superoxide anion and with a decrease in antioxidant status. Gut manipulation also resulted in neutrophil infiltration and oxidative stress in the lung as assessed by histology, myeloperoxidase activity, lipid peroxidation and antioxidant status. Heat conditioning before surgical manipulation had a protective effect against this intestinal and lung damage. CONCLUSION: This study suggests that mild whole-body hyperthermia before surgery might offer protection from postoperative complications.

Animals↗
PubMed2003

Chromosome 21 KIR channels in brain development.

Two KIR (K+ Inwardly Rectifying) channel genes have been identified on chromosome 21, in a region associated with important phenotypic features of trisomy 21, including mental retardation: KIR3.2 (GIRK2) and KIR4.2. We analysed the expression of these channel genes in developing human and mouse brains to determine the possible role of the corresponding channels in brain development and function. KIR3.2, which has been extensively studied in the mouse, was found to be expressed in the human cerebellum during development. The KIR4.2 channel is expressed later in development in both mice and humans. We compared the expression of these channels in terms of RNA and protein levels and discussed the potential synergy and consequences of the overexpression of these channels in Down's syndrome brain development.

Animals↗