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Biomedical subjects

J Williams

Publications and source records attributed to J Williams.

At least 55 records · Page 3Linked to original sources
PubMed2005

Pseudocholinesterase polymorphism in an Irish population.

BACKGROUND: Pseudocholinesterase polymorphism, as an example of pharmacogenetics with important clinical implications, has been widely studied and documented. However, data on a sample Irish population is lacking. We sought to provide this. METHOD: In an assay involving Ellman's reaction, pseudocholinesterase activity, alone and with dibucaine or fluoride as an inhibitor, was quantified using propionylthiocholine iodide as substrate. RESULTS: Pseudocholinesterase activities of 1.13-12.71 U/ml (mean +/- SD 6.74 +/- 2.04 U/ml) showed a normal distribution among our 116 healthy, non-medicated volunteers, aged 11-80 years (30.7 +/- 10.5 years) and weighing 46-114.6 kg (66.8 +/- 11.4 kg). However, dibucaine numbers from an inhibition study yielded a trimodal pattern consistent with the hypothesis of two allelic genes. Using an established nomenclature, 92 (79.3%) of our volunteers were homozygous for the usual form of the enzyme (E1uE1u). Of the 13 genotyped as E1uE1a, it is possible that 3 were misclassified and are probably E1kE1a. Only one volunteer was homozygous for the atypical form of the enzyme, with activity of 1.13 U/ml and dibucaine and fluoride number of 18.2 and 82.8, respectively. CONCLUSION: The continuous variation in pseudocholinesterase activity and the trimodal pattern of dibucaine numbers are both in accord with observations in other population groups. Although dibucaine number yields a trimodal pattern, its use could lead to misclassification of some E1kE1a as E1uE1a.

Journal Article↗
PubMed2005

Management of heart failure in primary care after implementation of the National Service Framework for Coronary Heart Disease: a cross-sectional study.

OBJECTIVES: To compare the management of heart failure with the standards set out in the National Service Framework for Coronary Heart Disease. STUDY DESIGN: A cross-sectional study in 26 general practices, with a combined list size of 256,188, that are members of the Kent, Surrey and Sussex Primary Care Research Network. METHODS: Information was extracted on the management of 2129 patients with heart failure, of whom 2097 were aged 45 years and over. RESULTS: The prevalence of heart failure was 8.3 per 1000. Prevalence rates increased with age, from 0.2 per 1000 in people aged under 35 years of age to 125 per 1000 in those aged 85 years and over. Coronary heart disease (present in 47%) was the most common comorbid condition in men with heart failure, whereas hypertension (present in 46%) was the most common condition in women. Recording of cardiovascular risk factors was generally higher in younger patients than in older patients, and in men than in women. Blood pressure (92% of men and 90% of women) and smoking status (84% of men and 77% of women) were generally the best-recorded cardiovascular risk factors. Blood electrolytes were recorded in about 83% of men and 75% of women. Only 17% of men and 11% of women with heart failure had a record of undergoing an echocardiogram. Use of angiotensin-converting enzyme (ACE) inhibitors or antagonists was 76% in men with heart failure and 68% in women; lowest rates were seen in older patients. Uptake of influenza immunization was generally high, at 85% in men and 84% in women. CONCLUSIONS: The use of ACE inhibitors in patients with heart failure was higher than in some previous studies. However, many patients have no documentation in their computerized medical records of having undergone key investigations, such as echocardiography.

Adult↗
PubMed2005

Voluntary counseling and HIV testing for pregnant women in the Kassena-Nankana district of northern Ghana: is couple counseling the way forward?

This study reports the results of a cross-sectional questionnaire survey undertaken in the Kassena-Nankana district of Ghana to assess the perception and attitude of 270 antenatal clinic attendants towards voluntary counseling and HIV testing. It was found that although 92.6% (95% CI 88.8-95.4) of respondents indicated a willingness to get tested, only 51% (95% CI 45.0-57.2) considered HIV testing for pregnant women to be useful. Most (93.6%) indicated they would like their husbands (partners) to know the result of the test and 52.2% indicated that their husbands would be willing to accompany them to antenatal clinic (ANC) at least once during the pregnancy. The perception of the usefulness of HIV testing (OR = 8.5, 95% CI 1.8-40.0), the willingness to disclose test result to the husband (OR = 13.3, 95% CI 4.0-44.5) and perceived willingness of husband to accompany wife to antenatal clinic (OR = 5.2, 95% CI 1.4-19.8) were found to be independent predictors of a woman's willingness to get tested. The willingness to disclose test result to husband (OR 3.2, 95% CI 1.1-10.5) and knowledge of at least one mode of MTCT HIV transmission (OR = 2.1, 95% CI 1.2-3.6) were found to be independent predictors of a woman's perception that getting tested was useful. The results suggest that for pregnant women in this district, the willingness to get tested for HIV does not equate with the perception of the test's usefulness, and that spouses are likely to exert strong influence on the attitude of pregnant women towards VCT. Couple counseling facilitated through couple-friendly ANC services should be explored as strategy for the intended VCT program in this district.

Adult↗
PubMed2005

Gabapentin is effective in the treatment of cancer-related neuropathic pain: a prospective, open-label study.

BACKGROUND: Gabapentin has been evaluated in the treatment of nonmalignant neuropathic pain, however, there is little direct evidence evaluating its efficacy in cancer-related neuropathic pain. OBJECTIVE: This study evaluated the effectiveness of gabapentin to treat cancer-related neuropathic pain. DESIGN: This was an open-label study. Two parallel groups of patients were recruited with either treatment-related (radiotherapy, surgery, chemotherapy) or tumor-related neuropathic pain. Gabapentin was dose-escalated from 300 mg/d to 1.8 g/d. MEASUREMENTS: The primary outcome, pain, was assessed using the modified brief pain inventory. In addition patient descriptors of pain and scores of activities of daily living were collated together with demographic data. RESULTS: We recruited 62 patients with treatment-related (n = 25) or tumor-related (n = 37) neuropathic pain. There was a significant reduction in the worst, average, and current pain scores (p < 0.002), but not the least pain score (p = 0.21). Twenty-eight of 62 (45.2%) of patients achieved at least a one third reduction in pain score (95% confidence interval [CI] 32.5-58.3); the number needed to treat to obtain this benefit is 2.2 (95% CI 1.7-3.1). There was a significant reduction in all scores measuring the impact of pain on daily living (p < 0.003). There was no significant difference in pain scores at day 8 compared to day 15. Analysis of variance suggested that gender, but not etiology, or type of neuropathic pain, was a significant predictor of analgesic response and this warrants further investigation. CONCLUSION: We conclude that gabapentin is an effective treatment for cancer-related neuropathic pain.

Aged↗
PubMed2005

Feed allowance-genotype interactions in broiler breeder hens.

Ad libitum feeding reduces livability and reproductive fitness in broiler breeder hens. Two genotypes, a standard (S) and an experimental dwarf broiler breeder (E), were fed ad libitum (SA and EA, respectively), restricted at 55% of ad libitum feed intake (intermediate restriction) from 6 to 15 wk of age (SI and EI, respectively), or restricted (SR and ER, respectively) to match a standard growth curve with a diluted mash feed (2,400 kcal/kg). The experiment was repeated at 2 locations (experiment 1 = 672 hens in pens from 0 to 40 wk; experiment 2 = 420 hens in pens and cages from 0 to 53 wk). Feed restriction reduced adult BW by 20% compared with ad libitum feeding, delayed sexual maturity by 2 to 4 wk, and improved livability. Hens fed the intermediate diet immediately compensated after 15 wk of age to reach BW, sexual maturity, and livability close to those of ad libitum-fed hens. The E genotype exhibited better tolerance to ad libitum feeding than the S genotype in all measured aspects. Average laying rate during the first 24 wk of lay was 66.4, 77.4, 69.9, 47.2, 57.9, and 72.4% for EA, EI, ER, SA, SI, and SR respectively in experiment 2. Egg abnormalities (double yolk, shell problems) decreased after the peak of lay but remained consistently higher for S compared with E, and for ad libitum and intermediate diets compared with the restricted diet. Yolk deposition rate was measured by a double dye technique. Duration of yolk rapid growth was 8.8 d in E and 9.3 d in S hens (P < 0.001), but this difference did not explain the observed variations in laying rate. The potential to increase feed allowances even with a diluted diet in broiler breeder hens requires adapted genotypes.

Aging↗
PubMed2005

Development of a measure of the health-related quality of life of children in public care.

OBJECTIVES: To validate PedsQL for children in public care and develop an 'in-care' module. DESIGN AND SETTING: Questionnaire development and validation. Questionnaires were completed in placement. A total of 69 children in public care (aged 8-18 years) and their carers were recruited through routine paediatric assessments, and 662 children not in public care were recruited from local schools. MEASURES: Self- and proxy-report versions of PedsQL generic module and the 'in-care' module. RESULTS: Cronbach's alpha for the generic module ranged from 0.66 to 0.88 and from 0.74 to 0.90 for self- and proxy-report respectively. Lower scores were reported for children in care compared with peers living at home for proxy- and self-report. Proxy- and self-report correlation ranged from 0.43 to 0.60 (P < 0.001). Cronbach's alpha for the in-care module was 0.87 and 0.91 for self- and proxy-report respectively. Proxy- and self-report scores showed significant correlation with generic module scores. The highest correlations were seen with sub-scales measuring Psychosocial Functioning (e.g. Emotional Functioning: Pearson's r = 0.67 and 0.59, P < 0.001 for self- and proxy-report respectively). Proxy- and self-report correlation was 0.45 (P < 0.001). CONCLUSIONS: We found PedsQL generic module and the newly developed 'in-care' module to have excellent internal reliability for self- and proxy-report. Validity was established for both measures and significant correlation found between child and proxy ratings. Although further testing of the measures is recommended, both have potential value in assessing the success of placements and could provide a reliable and valid tool for individual patient analysis in clinical practice and for research with this group.

Activities of Daily Living↗
PubMed2005

A technique for the measurement of renal ATP in a large animal model of septic shock.

BACKGROUND: The mechanisms responsible for acute renal failure in sepsis are not understood. Measurement of tissue ATP might help to understand this process but, in the large animal, it is hampered by major technical difficulties. OBJECTIVE: To develop a technique to monitor ATP in the kidney of a large mammal during the induction of septic shock and then circulatory arrest. METHODS: Implantation of a custom-made phosphorus coil around the left kidney. Induction of septic shock by intravenous E. coli administration. Acquisition of 31 P magnetic resonance (MR) spectroscopic data at 3-tesla before and during septic shock over several hours. Induction of euthanasia and measurement of the same 31 P signal immediately and thirty minutes after circulatory arrest. RESULTS: Clear reproducible 31 P MR spectra were obtained before and after the induction of septic shock and euthanasia. They indicated limited changes in ATP during septic shock. An expected rapid and dramatic decrease in ATP occurred with euthanasia. CONCLUSIONS: It is possible to sequentially monitor renal bioenergetics in a large mammal during septic shock using an implanted custom-made phosphorus coil and 3-tesla MR technology. This technique offers a novel approach to the investigation of septic renal failure.

Acute Kidney Injury↗
PubMed2005

Effect of the introduction of helical CT on radiation dose in the investigation of pulmonary embolism.

The aim of this study was to assess the change in patient radiation dose in the radiological investigation of pulmonary embolism since the introduction of helical CT pulmonary angiography (CTPA) in a large teaching hospital. All radiological investigations performed as an integral part of the imaging protocol in the investigation of clinically suspected pulmonary embolism (PE) were retrospectively reviewed. The protocol for the investigation of PE changed in our institution after the introduction of CTPA. Protocols 1 and 2 were the protocols in place before and after the introduction of CTPA, respectively. An in-depth evaluation was made of the imaging records and radiation dose for 30 consecutive patients investigated for clinically suspected PE in 1995 (protocol 1) and 2002 (protocol 2). Radiation doses were then extrapolated for the total number of patients investigated in each year. The number of radiological investigations performed per patient decreased from a mean of 1.17 in protocol 1 to 1.06 in protocol 2. There was a 44% increase in the total number of patients investigated. The effective dose per patient increased from 1.30 mSv to 1.35 mSv with the introduction of CTPA into the imaging protocol, an increase of only 4%. First line investigations showed a significant decrease in indeterminate examinations from 25.7% to 8.5%. Two different imaging protocols are reviewed with respect to type and number of procedures required for the investigation of PE and the resulting patient effective dose incurred. Results demonstrate an increase in the number of patients being investigated for suspected PE and a small increase in effective dose per patient since the introduction of helical CTPA. Although CTPA in itself incurs a higher effective dose, this is offset by the significant decrease in the number of non-diagnostic and total number of investigations per patient. In addition the ventilation component of lung scintigraphy was not required in protocol 2, thus reducing the dose further. We believe this small increase in effective dose is justified by the decrease in non-diagnostic studies and the reduction in total number of investigations per patient. We hope this paper will serve as a stimulus for the radiology community to examine current protocols in all areas of diagnostic imaging. We stress the importance of assessing new and established imaging investigative protocols to maximize the benefit and reduce any risk to patients.

Angiography↗
PubMed2004

Search for the lepton-flavor-violating leptonic B(0)-->mu(+/-)tau(-/+) and B(0)-->e(+/-)tau(-/+).

We have searched a sample of 9.6 x 10(6) BB events for the lepton-flavor-violating leptonic B decays, B(0)-->mu(+/-)tau(-/+) and B(0)-->e(+/-)tau(-/+). The tau lepton was detected through the decay modes tau-->lnunu(-) , where l=e, mu. There is no indication of a signal, and we obtain the 90% confidence level upper limits B(B(0)-->mu(+/-)tau(-/+))<3.8 x 10(-5) and B(B(0)-->e(+/-)tau(-/+))<1.3 x 10(-4).

Journal Article↗
PubMed2004

First results from the Cryogenic Dark Matter Search in the Soudan Underground Laboratory.

We report the first results from a search for weakly interacting massive particles (WIMPs) in the Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory. Four Ge and two Si detectors were operated for 52.6 live days, providing 19.4 kg d of Ge net exposure after cuts for recoil energies between 10 and 100 keV. A blind analysis was performed using only calibration data to define the energy threshold and selection criteria for nuclear-recoil candidates. Using the standard dark-matter halo and nuclear-physics WIMP model, these data set the world's lowest exclusion limits on the coherent WIMP-nucleon scalar cross section for all WIMP masses above 15 GeV/c2, ruling out a significant range of neutralino supersymmetric models. The minimum of this limit curve at the 90% C.L. is 4 x 10(-43) cm2 at a WIMP mass of 60 GeV/c2.

Journal Article↗
PubMed2004

First observation and Dalitz analysis of the D0-->K(0)Setapi(0) decay.

Using 9.0 fb(-1) of integrated luminosity in e(+)e(-) collisions near the Upsilon(4S) mass collected with the CLEO II.V detector we report the first observation of the decay D0-->K(0)(S)etapi(0). We measure the ratio of branching fractions, BR(D0-->K(0)(S)etapi(0))BR / (D0-->K(0)(S)pi(0))=0.46+/-0.07+/-0.06. We perform a Dalitz analysis of 155 selected D0-->K(0)(S)etapi(0) candidates and find leading contributions from a(0)(980)K(0)(S) and K(*)(892)eta intermediate states.

Journal Article↗
PubMed2004

Association analysis of two candidate phospholipase genes that map to the chromosome 15q15.1-15.3 region associated with reading disability.

Molecular genetic studies have suggested a reading disability (RD, dyslexia) susceptibility locus on chromosome 15q. We have previously mapped this locus by association to the region surrounding D15S994. Very little is known about the neurobiological processes involved in RD, and therefore selecting positional candidate genes for analysis based upon function is difficult. Nevertheless we were able to identify two functional candidates based upon existing hypotheses. Both were phospholipase genes, phospholipase C beta 2 (PLCB2) and phospholipase A2, group IVB (cytosolic; PLA2G4B). D15S944 is located within PLCB2 and is 1.6 Mb from PLA2G4B. We examined each gene for association using a mixed direct and indirect association approach, a case (n = 164)/control (n = 174) sample, and a partially overlapping sample of 178 RD parent-proband trios from South Wales and England. Mutation analysis revealed 14 sequence variants in PLCB2 and 33 variants in PLA2G4B. All non-synonymous SNPs were genotyped as were SNPs across each gene with maximum distance between SNPs of 6 kb. Case-control analyses revealed modest evidence (0.01 < P < 0.05) for association between a single variant in PLCB2 and two variants in PLA2G4B. However, association was not confirmed in the family based sample. As the latter sample has previously generated replicated significant evidence for association between RD and markers/haplotypes surrounding D15S944, it should have sufficient power to detect association to variants in susceptibility gene itself. We conclude that neither gene accounts for the association signal we previously observed. As these are the only clear cut functional candidate genes in the region, identification of the putative susceptibility locus for RD on 15q will require more methodical non-hypothesis driven positional cloning approaches.

Alleles↗