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Biomedical subjects

R Turner

Publications and source records attributed to R Turner.

At least 73 records · Page 4Linked to original sources
PubMed2000

An assessment of morbidity registers for coronary heart disease in primary care. ASSIST (ASSessment of Implementation STrategy) trial collaborative group.

BACKGROUND: Organised care delivered systematically to all patients with established coronary heart disease (CHD) can reduce their risk factors and improve their quality of life. Therefore, identifying all patients with established CHD in a general practice population is an important first step for delivering this effective healthcare. However, there is little information on how registers are compiled, the factors that predict inclusion on the register or the relationship between registration and level of care provided. AIM: To assess the completeness of morbidity registers for CHD in primary care, the factors that predict inclusion on the register, and the relationship between registration and level of care provided. METHOD: Observational study at baseline of 1979 patients aged 55 to 75 years with established CHD in 18 general practices recruited for a cluster randomised controlled trial. RESULTS: The proportion of CHD patients correctly identified on practice morbidity registers varied from 29.3% to 100%. Four factors were significantly and independently associated with being on a register: a relevant surgery contact since diagnosis (OR = 2.1, 95% CI = 1.6%-2.9%); a relevant repeat prescription since diagnosis (OR = 1.6, 95% CI = 1.1%-2.3%); a diagnosis of myocardial infarction (OR = 1.5, 95% CI = 1.2%-1.9%); and a revascularisation procedure (OR = 1.5, 95% CI = 1.1%-2.0%). Inclusion on a register was strongly associated with being adequately assessed (i.e. assessed for smoking status, blood pressure, and cholesterol) (OR = 1.8, 95% CI = 1.3%-2.3%) and with treatment with aspirin or a lipid-lowering agent (OR = 1.4 for each agent). CONCLUSION: A wide variation in registration levels between practices exists. There is evidence that practices using multiple methods of case detection achieve higher levels of registration. The association between registration and better care does not prove causality but an effective call-recall system is impossible without complete registration.

Aged↗
PubMed2000

Thromboembolism prophylaxis and incidence of thromboembolic complications after laparoscopic surgery.

UNLABELLED: The aim of this prospective study was to assess the clinical thrombo-embolic risk in laparoscopic digestive surgery. METHODS: The study prospectively included 2384 patients, who underwent laparoscopic surgery between June 1992 and June 1997. All patients received peri-operative low molecular weight heparin (LMWH) thromboprophylaxis. This regimen was administered until the patient resumed normal ambulatory activity. RESULTS: Eight cases (0.33%) of deep vein thrombosis (DVT) were observed, but no pulmonary embolism was noted. In 6 cases (5 cholecystectomies with reverse Trendelenburg position and 1 inguinal hernia repair), the pneumoperitoneum was more than 2 h, and in 2 cases (1 rectopexy and 1 sigmoid colectomy for diverticulitis), more than 3 h. In 6 out of the 8 cases, the diagnosis of DVT was established after cessation of LMWH delivery, after the patients were discharged home, and before post-operative day 10. CONCLUSION: During laparoscopic surgery, long operations and reverse Trendelenburg position are potentiating factors to DVT. Heparin prophylaxis for laparoscopic procedures should continue at least until discharge, and continued prophylaxis after discharge should only be considered in individual patients at continued high risk. We also recommend using graduated compression stockings, maintaining a relatively low insufflation pressure, keeping use of the reverse Trendelenburg position to a minimum, and intermittently releasing the pneumoperitoneum in longer procedures.

Adolescent↗
PubMed1999

Results from the low level mercury sorbent test at the Oak Ridge Y-12 Plant in Tennessee.

A mercury sorbent test was performed near the headwaters of the Upper East Fork Poplar Creek at the Oak Ridge Y-12 Plant in Tennessee. The sorbents SIR-200 (ResinTech), Keyle:X (SolmeteX), and GT-73 (Rohm and Haas) were the best materials tested for low level mercury removal. Each of these sorbents has a thiol-based active site. None of the tested sorbents reduced the mercury concentration to less than the existing 12 ng/l NPDES limit. For this small scale test, SIR-200, Keyle:X, and GT-73 reduced the mercury concentration to less than 51 ng/l, which is a regulatory treatment goal. The other sorbents tested, including granular activated carbon (Filtrasorb 300), did not reduce the mercury concentration below 51 ng/l at any tested flow up to 5 bed volumes per minute. Because of the cost and large volume of sorbent, a wastewater treatment plant for this stream would be prohibitively expensive to construct and maintain.

Absorption↗
PubMed1999

Plasma DNA microsatellites as tumor-specific markers and indicators of tumor progression in melanoma patients.

Multiple DNA microsatellites with frequent loss of heterozygosity (LOH) in melanomas have been demonstrated. The finding that free DNA is enriched in blood of melanoma patients prompted studies to determine whether tumor-specific DNA, such as DNA microsatellites exhibiting LOH, can be detected in blood and have clinical use. In this study, 57 advanced and 19 early clinically staged melanoma patients were assessed using 10 microsatellite markers on six chromosomes. Matched plasma and melanoma tissues from 40 patients showed significant concordance of LOH (P < 0.0001). The frequency of LOH microsatellite markers detected in plasma significantly increased in more advanced-staged patients. At locus D3S1293, LOH detection showed significant correlation to clinical disease progression (P = 0.02). Additionally, the combination of LOH microsatellite markers D9S157 and D3S1293 (P = 0.01), D9S157 and D1S228 (P = 0.05), and D11S925 and D3S1293 (P = 0.01) were significantly correlated to progression of different clinical stages of disease. These studies indicate that tumor-specific LOH markers in plasma have a potential clinical use as diagnostic and prognostic markers in melanoma patients.

Adult↗
PubMed1999

Functional magnetic resonance imaging in spontaneous attacks of SUNCT: short-lasting neuralgiform headache with conjunctival injection and tearing.

A 71-year-old woman presented with a short history of episodes of severe left-sided orbital and temporal pain in paroxysms lasting 60 to 90 seconds, and accompanied by ipsilateral lacrimation of the eye, rhinorrhea, and conjunctival injection. Results of clinical examination and structural imaging were normal and a clinical diagnosis of SUNCT (short-lasting unilateral neuralgiform pains with conjunctival injection and tearing) was made. The patient had a BOLD contrast-magnetic resonance imaging study in which significant activation was seen in the region of the ipsilateral hypothalamic gray, comparing the pain to pain-free state. The region of activation was the same in this patient as has been reported in acute attacks of cluster headache.

Aged↗
PubMed1999

The effect of slice order and thickness on fMRI activation data using multislice echo-planar imaging.

Multislice echo-planar imaging (EPI) is a commonly used technique for fMRI studies. Brain activation images acquired using fMRI are sensitive to T2* changes, reflecting the level of blood oxygenation (BOLD contrast), and may also contain an element of T1 contrast which detects blood flow changes in large vessels. If slice inflow (T1) effects are significant in multislice EPI, then as the order in which the slices are acquired is changed, differences in the activation maps are predicted. However, in experiments presented here using visual stimulation, the data demonstrate that highly consistent results can be achieved for repetition times (TR) of 6.0, 3.0, and 1.5 s. This suggests that, for whole-brain multislice EPI, fMRI activation is dominated by T2*, BOLD contrast. The thickness of the imaging slice is also an important parameter in these studies, having implications for spatial resolution, sensitivity, and acquisition time. In separate visual cortex experiments the effect on the values of the fMRI Z scores and the number of activated voxels is investigated as a function of slice thickness (from 1 to 8 mm). The maximum Z scores in the data are similar for all slice thicknesses and, after resampling to allow a direct comparison to be made, the volume of visual cortex detected as significantly activated increases with slice thickness.

Brain Mapping↗
PubMed1999

Genetic heterogeneity of autoimmune diabetes: age of presentation in adults is influenced by HLA DRB1 and DQB1 genotypes (UKPDS 43). UK Prospective Diabetes Study (UKPDS) Group.

AIMS/HYPOTHESIS: Juvenile-onset, insulin-dependent diabetes is associated with islet cell antibodies and with specific "high-risk" HLA-DRB1 and HLA-DQB1 genotypes. Patients with Type II (non-insulin-dependent) diabetes mellitus can have islet-related antibodies, but the genotypic associations at different ages of onset have not been evaluated. Our aim was to determine (i) the prevalence of DRB1 and DQB1 genotypes in patients at diagnosis of Type II diabetes at different ages from 25 to 65 years compared with the general population, and (ii) whether the presence of islet cell antibodies (ICA) or glutamic acid decarboxylase antibodies (GADA) or both by age is associated with different DRB1 and DQB1 genotypes. METHODS: The antibodies to islet cells and those to glutamic acid decarboxylase were measured in 1712 white Caucasian diabetic subjects at diagnosis of diabetes and they were genotyped for HLA DRB1*03 and DRB1*04 and the high-risk DRB1*04-DQB1* 0302 haplotype. To assess over-representation of high-risk alleles for Type I (insulin-dependent) diabetes mellitus, the prevalence of high-risk alleles in diabetic patients was expressed relative to the prevalence of low-risk alleles, non-DR3/non-DR4, that provided a reference denominator in both the diabetic patients and in 200 non-diabetic control subjects. The prevalence of ICA or GADA or both in patients with different HLA genotypes was assessed in those diagnosed in four age groups, 25-34 years, 35-44 years, 45-54 years and 55-65 years. RESULTS: In Type II diabetic patients presenting at ages 25-34, 35-44 and 45-54 years, there was an increased prevalence of DR3/DR4 compared with the general population with approximately 6.5-fold, 2.9-fold, 2.1-fold over-representation, respectively (p < 0.0001, < 0.01, < 0.05) but this was not found in those aged 55-65 years old. In the group aged 25-34 years, 32 % of patients with ICA or GADA or both had DRB1*03/DRB1*04-DQB1*0302 compared with 10% in those aged 55-65 years and expected 3% prevalence. Conversely, only 14% of those aged 25-34 years with antibodies had non-DR3/non-DR4, compared with 35 % in those aged 55-65 years. There was thus pronounced age heterogeneity in DRB1 and DQB1 predisposition to Type II diabetes. The antibodies displaced DRB1 or DQB1 genotypes in the multivariate model for requiring insulin therapy by 6 years of follow-up. CONCLUSION/HYPOTHESIS: The age of presentation of Type I diabetes in adulthood was in part dependent on the DRB1/DQB1 genotype. Islet cell antibodies and glutamic acid decarboxylase antibodies were strongly associated with DRB1*03/DRB1*04-DQB1*0302 in early adulthood but showed little relation with specific HLA genotypes after the age of 55 years.

Adult↗
PubMed1999

Sequence variants of the sarco(endo)plasmic reticulum Ca(2+)-transport ATPase 3 gene (SERCA3) in Caucasian type II diabetic patients (UK Prospective Diabetes Study 48).

AIMS/HYPOTHESIS: Type II (non-insulin-dependent) diabetes mellitus is a common heterogeneous metabolic disorder of largely unknown genetic aetiology. The sarco(endo)plasmic reticulum Ca(2+)-transport ATPase (SERCA) plays an important part in the glucose-activated beta-cell Ca(2+) signalling that regulates insulin secretion. Impaired function and expression of SERCA have been shown in islets of Langerhans from diabetic animal models and have also been associated with beta-cell apoptosis. Thus, the SERCA3 encoding gene is a plausible candidate for a primary pancreatic beta-cell defect. METHODS: In this study, the entire coding and the promoter regions of SERCA3 gene were screened by single-strand conformation polymorphism analysis in white Caucasian Type II diabetic patients. RESULTS: We found four rare missense mutations [Exon 4: Gln(108)-->His (CAG-->CAT), Exon 14: Val(648) -->Met (GTG-->ATG) and Arg(674)-->Cys (CGC--> TGC), and Exon 15: Ile(753)-->Leu (ATC-->CTC)]. The patients with Gln(108)-->His, Val(648)-->Met and Arg(674)-->Cys mutations, which may affect the E1P-E2P transition of SERCA3 during its enzyme cycle, had normal body weight with marked hyperglycaemia and beta-cell dysfunction. That is an unusual phenotype only found in 6 % of the Type II diabetic patients recruited for the UK Prospective Diabetes Study. In addition, five silent polymorphisms, six intron variants and two polymorphisms in the 3' untranslated region of exon 22 were found with similar frequency in diabetic and control subjects. CONCLUSION/INTERPRETATION: Our result suggests that in white Caucasians, the SERCA3 locus possibly contributes to the genetic susceptibility to Type II diabetes [Diabetologia (1999) 42: 1240-1243].

Calcium-Transporting ATPases↗
PubMed1999

The use of diagnostic laparoscopy supported by laparoscopic ultrasonography in the assessment of pancreatic cancer.

BACKGROUND: Pancreatic resection with curative intent is possible in a select minority of patients with carcinomas of the pancreatic head. Diagnostic laparoscopy supported by laparoscopic ultrasonography combines the proven benefits of staging laparoscopy with high-resolution intraoperative ultrasound, thus allowing the surgeon to perform a detailed assessment of the pancreatic cancer. METHODS: In a prospective study of 26 patients with obstructive jaundice from a carcinoma of the head of the pancreas, the curative resectability of tumors was assessed by ultrasound (26 cases), computerized tomography (26 cases), endoscopic ultrasound (16 cases), and a combination of diagnostic laparoscopy and laparoscopic ultrasound (26 cases). RESULTS: The findings of ultrasound and computerized tomography were comparable: 50% of patients were excluded from curative resection. Endoscopic ultrasound provided precise information on the primary tumors. The accuracy of the combined diagnostic laparoscopy and laparoscopic ultrasound, when compared with ultrasound, computerized tomography, and endoscopic ultrasound, was better with respect to minute peritoneal or hepatic metastasis: 80.7% (or a further 30.7%) of patients did not qualify for curative resection. CONCLUSIONS: Diagnostic laparoscopy supported by laparoscopic ultrasonography enables detection of previously unsuspected metastases; thus, needless laparotomy can be avoided. It should therefore be considered the first step in any potentially curative surgical procedure.

Endosonography↗
PubMed1999

Autopsy can be performed laparoscopically.

A case of laparoscopic autopsy for unexplained inpatient death is reported. The procedure is minimally invasive, easy to perform, accurate, and not disfiguring, rendering it easy to accept among mourning families.

Aged↗
PubMed1999

Beagle 2: a proposed exobiology lander for ESA's 2003 Mars Express mission.

The aim of the proposed Beagle 2 small lander for ESA's 2003 Mars Express mission is to search for organic material on and below the surface of Mars and to study the inorganic chemistry and mineralogy of the landing site. The lander will have a total mass of 60kg including entry, descent, and landing system. Experiments will be deployed on the surface using a robotic arm. It will use a mechanical mole and grinder to obtain samples from below the surface, under rocks, and inside rocks. Sample analysis by a mass spectrometer will include isotopic analysis. An optical microscope, an X-ray spectrometer and a Mossbauer spectrometer will conduct in-situ rock studies.

Equipment Design↗
PubMed1999

The use of the Rotterdam Symptom Checklist in palliative care.

The Rotterdam Symptom Checklist (RSCL), which measures both physical and psychological aspects of quality of life (QOL), was given to all new patients admitted to a palliative care unit who were thought capable of filling out a questionnaire as an outcome measure of symptom control. Assessments were obtained from 52 patients at baseline (week 1). This represented only 53% of the new patients admitted to the unit. Thirty-one patients completed a second questionnaire at week 2, and only 28 patients completed a third (week 3). In these selected patients, the median overall RSCL scores were 57, 52, and 49 at weeks 1, 2, and 3. There was a significant improvement in QOL scores across the three measurements with a significant difference between weeks 1 and 3 (P = 0.05) but not between weeks 1 and 2. Primarily because of the inability of many patients to complete the questionnaire and the high attrition rate, the appropriateness of this tool as a symptom control measure in palliative care patients is questioned.

Adult↗
PubMed1999

Small intestinal Na+,K+-adenosine triphosphatase activity and gene expression in experimental diabetes mellitus.

The Na+,K+-ATPase plays a key role in the absorption of electrolytes, water, and nutrients from the small intestine. The effect of streptozotocin-induced diabetes mellitus (STZ-DM) on the activity and expression of Na+,K+-ATPase in the rat small intestine was examined in the present study. Diabetes mellitus was induced by a single intraperitoneal injection of STZ (75 mg/kg) and control and STZ-DM rats were killed at day 30 (chronic diabetic state). Levels of Na+,K+-ATPase activity and numbers of sodium pumps were increased two- to threefold in the jejunum and ileum. Sodium pump kinetics were unaltered in STZ-DM. The levels of Na+,K+-ATPase alpha1 and beta1 isoform protein, corresponding mRNAs, and levels of transcription were increased in the jejunal and ileal mucosa of the chronically diabetic rat. The increases in Na+,K+-ATPase functional activity, protein expression, and mRNA were most marked at the level of the ileal mucosa. While a proximal to distal gradient in Na+,K+-ATPase activity and subunit isoform protein levels were observed in both control and diabetic rats, levels of subunit isoform mRNA abundance were similar in both regions of the small intestine in both groups of rats. The alterations in small intestinal Na+,K+-ATPase expression in the chronic diabetic state appear to involve alterations in transcriptional and posttranscriptional events and may likely represent an adaptive response that leads to increased Na+-coupled monosaccharide absorption in the context of a perceived state of nutrient depletion.

Animals↗
PubMed1999

Measuring cerebral blood flow using magnetic resonance imaging techniques.

Magnetic resonance imaging techniques measuring CBF have developed rapidly in the last decade, resulting in a wide range of available methods. The most successful approaches are based either on dynamic tracking of a bolus of a paramagnetic contrast agent (dynamic susceptibility contrast) or on arterial spin labeling. This review discusses their principles, possible pitfalls, and potential for absolute quantification and outlines clinical and neuroscientific applications.

Animals↗