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Biomedical subjects

R Taylor

Publications and source records attributed to R Taylor.

At least 181 records · Page 10Linked to original sources
PubMed1999

Anxiety and depression in patients with an intracranial neoplasm before and after tumour surgery.

The aims of this prospective study were to investigate levels of anxiety and depression in patients with a solitary intracranial neoplasm before and after surgery, and to determine if relationships exist between high levels of anxiety or depression and the hemispheric location of the tumour, the tumour type or patient gender. Patients aged between 17 and 79 years with a solitary intracranial neoplasm completed the Hospital Anxiety and Depression Scale (HAD) before and after biopsy or resective tumour surgery. A control group of non-brain-damaged subjects also completed the HAD before and after lumbar spinal surgery. Of the 109 patients with a brain tumour 30 and 16% demonstrated the likely presence of anxiety and depression, respectively, according to HAD scoring criteria. A greater proportion of females with a left hemisphere tumour reported higher levels of emotional disturbance than any other group of patients; relationships between dysphasia and levels of anxiety or depression were not significant. Patients with a meningioma had higher levels of anxiety and depression as measured by the HAD than those with any other tumour types. Levels of both anxiety and depression were significantly lower after tumour surgery according to the HAD. There were no significant differences in HAD scores between (a) left and right hemispheric tumour groups, and (b) the tumour and control (n = 20) groups. This study has found that anxiety and depression as measured by the HAD are relatively uncommon in patients with an intracranial neoplasm, and that levels of mood disturbance do not differ significantly from those in patients undergoing lumbar spinal surgery. Levels of anxiety and depression become lower after surgery in patients with a brain tumour. Patterns of anxiety and depression in patients with a brain tumour appear to differ from those reported in stroke.

Adolescent↗
PubMed1999

An epidemic of burkholderia cepacia transmitted between patients with and without cystic fibrosis.

Burkholderia cepacia is an important pathogen in cystic fibrosis (CF) and an infrequent cause of nosocomial infection in non-CF patients. This report describes a large hospital outbreak that appeared to involve both patient groups, a previously unrecognized phenomenon. Ribotype restriction fragment length polymorphism (RFLP) profiles and pulsed-field gel electrophoresis-resolved macrochromosomal RFLPs were analyzed, a ribotype-based phylogenic tree was constructed, and case-control and cohort studies were performed. A single dominant clone was found in both CF and non-CF groups. Phylogenic analysis suggests that it has evolved independently and that such highly transmissible strains can emerge rapidly and randomly. Acquisition risk in the CF patients was linked to hospitalization (odds ratio=5.47, P=.0158, confidence interval=1. 28-26.86) and was associated with significantly increased mortality rates. Infection control policies must now consider this threat of transmission between non-CF and CF patients.

Adolescent↗
PubMed1999

Prenatal diagnosis and the subsequent mutation analysis in a family with carbohydrate-deficient glycoprotein type I syndrome: growing evidence to support founder effects within CDG1 populations.

Carbohydrate deficient-glycoprotein syndrome type I (CDG1 or Jaeken Syndrome) is an autosomal recessive multisystem disease with severe early involvement of the nervous system. Mutations in the phosphomannomutase 2 (PMM2) gene have recently been identified in 16 affected individuals. In the current study, we have described a CDG1 family where gene tracking had been used to perform prenatal diagnosis before the isolation of the CDG1 gene. Haplotype analysis indicated that the unborn child had inherited the maternal 'normal' allele, but a critical recombination event meant that it was impossible to determine if the child had inherited the paternal mutation. Single-strand conformation polymorphism and sequence analysis revealed that the mother was a carrier of a C-->A transversion at position 357 (F119L), and that the father was a carrier of a G-->A transition at position 425 (R141H). The unborn child had inherited the paternal R141H mutation. Because only three mutations have previously been reported in UK families, of which F119L and R141H are two, and given that there is evidence of allelic association in CDG1 families, it is possible that a limited number of ancestral mutations have given rise to most cases of CDG1 in any one population.

Chromosomes, Human, Pair 16↗
PubMed1999

Adipocyte insulin action following ovulation in polycystic ovarian syndrome.

The role of anovulation and insulin resistance in the pathogenesis of polycystic ovarian syndrome (PCOS) remains to be determined. The aim of this study was to investigate whether the metabolic abnormality of insulin resistance in PCOS reflects, rather than causes, the ovarian dysfunction. Eight subjects with classical PCOS were studied on two occasions. Adipocyte insulin sensitivity together with hormonal and metabolic changes were investigated in patients with PCOS following prolonged amenorrhoea and then again in the early follicular phase after ovulation. Insulin receptor binding in amenorrhoeic subjects with PCOS was low at 0.78 +/- 0.08% and this increased to 1.18 +/- 0.19% after an ovulatory cycle (P < 0.05). Maximal insulin stimulated 3-O-methylglucose uptake was 0.70 +/- 0. 14 during amenorrhoea and increased to 1.08 +/- 0.25 pmol/10 cm(2) cell membrane (P < 0.05). Plasma testosterone fell (4.0 +/- 0.4 to 2. 3 +/- 0.2 nmol/l; P < 0.001), luteinizing hormone fell (17.6 +/- 2.3 to 6.7 +/- 0.8 IU/l; P < 0.001) but plasma insulin concentrations remained unchanged following ovulation (14.6 +/- 1.9 and 15.7 +/- 3. 8 pmol/l during amenorrhoea and after ovulation respectively). The results of this study suggest that chronic anovulation per se appears to modify the factors contributing to cellular insulin resistance seen in PCOS.

3-O-Methylglucose↗
PubMed1999

Carbonyl-carbonyl interactions stabilize the partially allowed Ramachandran conformations of asparagine and aspartic acid.

Asparagine and aspartate are known to adopt conformations in the left-handed alpha-helical region and other partially allowed regions of the Ramachandran plot more readily than any other non-glycyl amino acids. The reason for this preference has not been established. An examination of the local environments of asparagine and aspartic acid in protein structures with a resolution better than 1.5 A revealed that their side-chain carbonyls are frequently within 4 A of their own backbone carbonyl or the backbone carbonyl of the previous residue. Calculations using protein structures with a resolution better than 1.8 A reveal that this close contact occurs in more than 80% of cases. This carbonyl-carbonyl interaction offers an energetic sabilization for the partially allowed conformations of asparagine and aspartic acid with respect to all other non-glycyl amino acids. The non-covalent attractive interactions between the dipoles of two carbonyls has recently been calculated to have an energy comparable to that of a hydrogen bond. The preponderance of asparagine in the left-handed alpha-helical region, and in general of aspartic acid and asparagine in the partially allowed regions of the Ramachandran plot, may be a consequence of this carbonyl-carbonyl stacking interaction.

Amino Acids↗
PubMed1999

Effect of varying doses of potassium-magnesium citrate on thiazide-induced hypokalemia and magnesium loss.

The purpose of this study was to compare the efficacy of three dosages of potassium-magnesium citrate in overcoming thiazide-induced hypokalemia and magnesium loss and increasing urinary pH and citrate. Sixty-one normal subjects first took hydrochlorothiazide at 50 mg/d. After 3 weeks of thiazide treatment or earlier if hypokalemia developed, the subjects were randomized to take one of three dosages of potassium-magnesium citrate (K ( 4 ) MgCit ( 2 ) ) for 3 weeks while continuing on the thiazide: 4 tablets per day (24 mEq potassium, 12 mEq magnesium, and 36 mEq citrate per day), 7 tablets per day (49 mEq potassium, 24.5 mEq magnesium, and 73.5 mEq citrate per day), or 10 tablets per day (70 mEq potassium, 35 mEq magnesium, and 105 mEq citrate per day). Outcome measures were changes in serum potassium and magnesium and urinary potassium, magnesium, pH, and citrate. All three dosages of potassium-magnesium citrate significantly increased serum potassium concentration, with >80% of subjects regaining normal values despite continued thiazide therapy. The two higher dosages, but not the lowest dosage, caused a small but significant increase in serum magnesium concentration, while substantially increasing urinary magnesium. All three dosages significantly increased urinary pH and citrate in a dose-dependent manner. The lowest dosage produced increases sufficient to prevent stone recurrence. Side effects of thiazide therapy were ameliorated by the highest dosage but not by the two lower dosages. Potassium-magnesium citrate at a dosage of 4 tablets per day is adequate to correct thiazide-induced hypokalemia and to increase urinary pH and citrate sufficiently for stone prevention. Higher dosages are probably required for the prevention of magnesium loss and adverse symptoms of thiazide therapy.

Adult↗
PubMed1999

Socio-economic, migrant and geographic differentials in coronary heart disease occurrence in New South Wales.

OBJECTIVE: This study examines the variation in coronary heart disease (CHD) mortality and acute myocardial infarction (AMI) by socio-economic status (SES), country of birth (COB) and geography (urban/rural) in the total population of New South Wales (Australia) in 1991-95. METHOD: CHD deaths and AMI are from complete enumerations of deaths and hospital admissions, respectively; and population denominators are from census information. Data are examined separately by sex, and comparisons of SES groups (based on municipalities), COB and region are analysed using Poisson regression, after adjustment for age. RESULTS: The study identified higher risk for AMI admissions and CHD mortality in lower SES populations with significant linear trends, for both sexes, adjusted for age, region and COB. According to the population attributable fractions (PAF), 23-41% of the risk of CHD occurrence is due to SES lower than the highest quartile. The higher age-adjusted risk for CHD occurrence in rural and remote populations for both sexes, compared with urban communities, was lessened by adjustment for COB, and all but abolished when also adjusted for SES.COB analysis indicated significantly lower age-adjusted AMI admissions and CHD mortality compared with the Australian-born. CONCLUSIONS: Higher risks for CHD in rural populations compared with the capital city (Sydney) are due, in part, to lower SES, lesser migrant composition. IMPLICATIONS: Strategies for reducing CHD differentials should consider demographic factors and the fundamental need to reduce socio-economic inequalities, as well as targeting appropriate prevention measures.

Adult↗
PubMed1999

The association between needs and quality of life in an epidemiologically representative sample of people with psychosis.

The impact of meeting needs on quality of life in the severely mentally ill is investigated in this study. An epidemiologically representative sample of 133 patients meeting ICD-10 criteria for psychosis completed standardized instruments for measuring needs and quality of life. Covariance structure modelling was used to investigate the extent to which latent factors of met and unmet need were associated with latent quality of life. Patients rated about 0.7 more total (met plus unmet) needs than staff, mainly due to differences in rating unmet need. Patient ratings were more reliable than ratings by others of unmet need and quality of life. Both underlying unmet need and met need were negatively associated with underlying quality of life, but unmet need was the stronger relationship. The patient's perspective on their difficulties (especially their unmet needs) must be central to mental health care.

Adolescent↗
PubMed1999

Development of an in vitro bioassay for Clostridium botulinum type B neurotoxin in foods that is more sensitive than the mouse bioassay.

A novel, in vitro bioassay for detection of the botulinum type B neurotoxin in a range of media was developed. The assay is amplified by the enzymic activity of the neurotoxin's light chain and includes the following three stages: first, a small, monoclonal antibody-based immunoaffinity column captures the toxin; second, a peptide substrate is cleaved by using the endopeptidase activity of the type B neurotoxin; and finally, a modified enzyme-linked immunoassay system detects the peptide cleavage products. The assay is highly specific for type B neurotoxin and is capable of detecting type B toxin at a concentration of 5 pg ml(-1) (0.5 mouse 50% lethal dose ml(-1)) in approximately 5 h. The format of the test was found to be suitable for detecting botulinum type B toxin in a range of foodstuffs with a sensitivity that exceeds the sensitivity of the mouse assay. Using highly specific monoclonal antibodies as the capture phase, we found that the endopeptidase assay was capable of differentiating between the type B neurotoxins produced by proteolytic and nonproteolytic strains of Clostridium botulinum type B.

Animals↗
PubMed1999

Use of the functional assessment measure (FIM+FAM) in head injury rehabilitation: a psychometric analysis.

OBJECTIVES: The drive to measure outcome during rehabilitation after brain injury has led to the increased use of the functional assessment measure (FIM+FAM), a 30 item, seven level ordinal scale. The objectives of the study were to determine the psychometric structure, internal consistency, and other characteristics of the measure. METHODS: Psychometric analyses including both traditional principal components analysis and Rasch analysis were carried out on FIM+FAM data from 2268 assessments in 965 patients from 11 brain injury rehabilitation programmes. RESULTS: Two emergent principal components were characterised as representing physical and cognitive functioning respectively. Subscales based on these components were shown to have high internal consistency and reliability. These subscales and the full scale conformed only partially to a Rasch model. Use of raw item ratings, as opposed to transformed ratings, to produce summary scores for the two subscales and the full scale did not introduce serious distortion. CONCLUSION: The full FIM+FAM scale and two derived subscales have high internal reliability and the use of untransformed ratings should be adequate for most clinical and research purposes in comparable samples of patients with head injury.

Activities of Daily Living↗
PubMed1999

ACE inhibition and fibroblast growth factor in cultured human vascular smooth muscle.

The effects of the angiotensin converting enzyme (ACE) inhibitor, enalaprilat, and basic fibroblast growth factor (bFGF) on DNA synthesis and expression of ACE mRNA were examined in human vascular smooth muscle cells cultured from saphenous vein and internal mammary artery. DNA synthesis was estimated using 3H-thymidine uptake, and ACE mRNA was estimated by rt-PCR. Enalaprilat (0.125 microg/ml, 48 h) decreased 3H-thymidine uptake to 66+/-12% (SE) of the control without enalaprilat (p < 0.05). Basic FGF (10 ng/ml, 24 h) increased uptake by 41 +/- 12% (p < 0.05) while enalaprilat pretreatment (24 h) decreased uptake to 56 +/- 12% of this augmented value (p < 0.025). Basic FGF increased ACE mRNA, a process that was time dependent with an approximately 50% increase after 24 h exposure. Pre-exposure to enalaprilat (24 h) before bFGF reduced ACE mRNA to approximately 50% of that found in the presence of bFGF alone. The results indicate that ACE mRNA is present in human vascular smooth muscle cells and that exposure to an ACE inhibitor reduces DNA synthesis. Basic FGF stimulates DNA synthesis and ACE mRNA expression, and both of these effects are reduced by an ACE inhibitor. The results are consistent with the effects of bFGF being exerted through, or alternatively in concert with, angiotensin II. Further, they suggest that ACE inhibition can reduce the activity of the renin-angiotensin system by inhibiting the production of ACE, or at least the expression of ACE mRNA, in addition to producing enzyme inhibition at the ACE level.

Adult↗
PubMed1999

Persisting symptoms and carers' views of outcome after subarachnoid haemorrhage.

OBJECTIVE: To report the outcome of aneurysmal subarachnoid haemorrhage (SAH) in terms of subjective symptoms and carers' perspective over a period of two years. DESIGN: Forty-four consecutive patients admitted to a Regional Neurosurgical Unit and who survived aneurysmal SAH were invited for outpatient assessment at 6, 12 and 24 months post haemorrhage. MEASURES: The Glasgow Outcome Scale (GOS) was used to measure global outcome; the Hospital Anxiety and Depression Scale (HAD) to screen for affective symptoms; the Head Injury Symptom Checklist (HISC) to detect symptoms commonly reported after head trauma; and information was collected from a close friend or relative of the patient using the Relative's Questionnaire (RQ). RESULTS: GOS outcome was significantly related to the severity of the original haemorrhage, as classified by the World Federation of Neurological Surgeons (WFNS) Grading Scale, on admission to hospital. However, even in cases where patients had made a good recovery according to the GOS, a variety of problems were frequently reported by patients and relatives, and many of these persisted for the duration of the study. The three most common and persistent symptoms were tiredness (63%, 59% and 59% at 6, 12 and 24 months respectively), memory disturbance (50%, 52% and 56%) and passivity (61%, 47% and 46%). In contrast, the prevalence of disturbed mood, as reported using the HAD, was similar to that of the general population. CONCLUSIONS: Studies of outcome following SAH should address these subtle disturbances, and information pertaining to potential long-term problems should be provided to patients and relevant others.

Activities of Daily Living↗
PubMed1999

The influence of weight-bearing on the measurement of polyethylene wear in THA.

We have studied the influence of weight-bearing on the measurement of wear of the polyethylene acetabular component in total hip arthroplasty using two techniques. The measured vertical wear was significantly greater when radiographs were taken weight-bearing rather than with the patient supine (p = 0.001, method 1; p = 0.007, method 2). Calculations of rates of linear wear of the acetabular component were significantly underestimated (p < 0.05) when radiographs were taken supine. There are two reasons for this. First, a change in pelvic orientation when bearing weight ensures that the thinnest polyethylene is brought into relief, and secondly, the head of the femoral component assumes the position of maximal displacement along its wear path. Interpretation of previous studies on both linear and volumetric polyethylene wear in total hip arthroplasty should be reassessed in the light of these findings.

Acetabulum↗
PubMed1999

Automated purification and quantification of oligonucleotides.

We have developed automated methods for the trityl-on purification and quantification of synthetic oligonucleotides. Oligonucleotide purification is by solid-phase extraction cartridges using Amberchrom CG-50 resin on an XYZ-axis robotic system. Quantification is by OD260nm using an online UV-visible spectrophotometer with sipper. The purification of 20 oligonucleotides requires 5 min of user set-up time, plus 20 min per sample of robot time. For a 15-25-mer at the 40 nmol scale of synthesis, the method gives a yield of 2.8 ODs from a load of 10.1 OD, i.e., a 28% average yield. Oligonucleotides purified by this method have proven to be successful for primers for automated DNA sequencing.

Autoanalysis↗