Search PubMed⌕ Search

Biomedical subjects

M Taylor

Publications and source records attributed to M Taylor.

At least 163 records · Page 9Linked to original sources
PubMed2001

Interstitial laser: a new surgical technique for twin reversed arterial perfusion sequence in early pregnancy.

Current treatments for twin reversed arterial perfusion sequence are associated with significant morbidity and most are not feasible in early gestation. We report the use of an interstitial laser in two pregnancies complicated by this sequence at 14 and 15 weeks, respectively. A 600 microm laser fibre was introduced via a 17 gauge needle into the abdomen of the perfused twin close to the vitelline artery and umbilical vein, which were occluded by neodymium:yttrium aluminium garnet (Nd:YAG) laser. Both pregnancies continued uneventfully and each resulted in the birth of a healthy baby at term.

Female↗
PubMed2001

An evaluation of myocardial fatty acid and glucose uptake using PET with [18F]fluoro-6-thia-heptadecanoic acid and [18F]FDG in Patients with Congestive Heart Failure.

UNLABELLED: Understanding the metabolic consequences of heart failure is important in evaluating potential mechanisms for disease progression and assessing targets for therapies designed to improve myocardial metabolism in patients with heart failure. PET is uniquely suited to noninvasively evaluate myocardial metabolism. In this study, we investigated the kinetics of 14(R,S)-[18F]fluoro-6-thia-heptadecanoic acid (FTHA) and [18F]FDG in patients with stable New York Heart Association functional class III congestive heart failure and a left ventricular ejection fraction of no more than 35%. METHODS: Twelve fasting patients underwent dynamic PET studies using [18F]FTHA and FDG. From the dynamic image data, the fractional uptake rates (Ki) were determined for [18F]FTHA and FDG. Subsequently, serum free fatty acid and glucose concentrations were used to calculate the myocardial free fatty acid and glucose uptake rates, respectively. Uptake rates were compared with reported values for [18F]FTHA and FDG in subjects with normal left ventricular function. RESULTS: The average Ki for [18F]FTHA was 19.7 +/- 9.3 mL/100 g/min (range, 7.2-36.0 ml/100 g/min). The average myocardial fatty acid use was 19.3 +/- 2.3 mmol/100 g/min. The average Ki for FDG was 1.5 +/- 0.37 mL/100 g/min (range, 0.1-3.3 mL/100 g/min), and the average myocardial glucose use was 12.3 +/- 2.3 mmol/100 g/min. CONCLUSION: Myocardial free fatty acid and glucose use in heart failure can be quantitatively assessed using PET with [18F]FTHA and FDG. Myocardial fatty acid uptake rates in heart failure are higher than expected for the normal heart, whereas myocardial glucose uptake rates are lower. This shift in myocardial substrate use may be an indication of impaired energy efficiency in the failing heart, providing a target for therapies directed at improving myocardial energy efficiency.

Cardiomyopathy, Dilated↗
PubMed2001

A health and nutritional profile of rural school children in KwaZulu-Natal, South Africa.

A community-based cross-sectional study was undertaken to measure anthropometric indices, micronutrient status and prevalence of parasite infections in 579 rural South African primary school children. Eleven schools were selected randomly from a Magisterial District in southern KwaZulu-Natal (KZN). In each school, all pupils aged between 8 and 10 years were selected. The following outcome measures were obtained: anthropometric--height for age, weight for age and body mass index; micronutrient status--anaemia, serum ferritin and vitamin A; and prevalence of parasite infections--Ascaris lumbricoides, Trichuris trichiura and Schistosoma haematobium. The observed prevalences were: stunting 7.3%, underweight for age 0.7%, and obesity 3.1%; anaemia 16.5% (Hb < 12 g/dl), vitamin A deficiency 34.7% (serum retinol < 20 micrograms/dl) and 28.1% with reduced serum ferritin (< 12 ng/ml); Trichuris trichiura 53.9%, Ascaris lumbricoides 27.3% and Schistosoma haematobium 24.5%. We conclude that micronutrient deficiency, parasitic infestations and stunting remain significant problems among school-aged children in South Africa. Micronutrient supplementation and de-worming provide opportunities for school-based health promotion and primary health care interventions, and might produce significant health and educational benefits.

Anemia↗
PubMed2001

Psychological consequences of surgical menopause.

More than 250,000 women have a bilateral oophorectomy every year. With surgical menopause, the onset of menopausal symptoms is abrupt and often dramatic. Oophorectomy offers relief from physical conditions for many women; however, those with preexisting psychological and some physical problems tend to experience postsurgical exacerbation of those problems. Loss of estrogenic and androgenic underpinnings may destabilize women with unstable psychiatric axes. Surgically menopausal women may also experience a decline in sexual interest and activity. The relation of surgical menopause to physiologic and sexual well-being is described in this article. The link between hormonal levels and psychological well-being has been well documented. Depression seems to be increased at times of changing hormone levels in women, possibly a result of the effect of estrogen levels on serotonergic activity and its impact on other neurotransmitters. In addition, a sex-specific association with specific psychological disorders has been described in the literature and will be reviewed in this article. The potential benefits of estrogen or estrogen/androgen therapy on libido and mood are discussed, as are findings that estrogen-androgen therapy correlated with less anxiety and hostility and with increased positive feelings when compared with estrogen-only treatment.

Adult↗
PubMed2001

Association of ARNT splice variants with estrogen receptor-negative breast cancer, poor induction of vascular endothelial growth factor under hypoxia, and poor prognosis.

The aryl hydrocarbon receptor nuclear translocator (ARNT) is a basic helix-loop-helix transcription factor that forms heterodimers with the aryl hydrocarbon receptor (AhR) or hypoxia inducible factor-1alpha to activate transcription via xenobiotic response element or hypoxia response element, respectively. Thus, it plays a major role in two key biochemical pathways involved in tumor growth. We previously showed that estrogen receptor (ER)-negative breast cancer cell lines expressed a splice variant of ARNT that was associated with Ah nonresponsiveness. We have now used a sensitive PCR method to analyze the expression of the variant in a series of 92 breast cancers to assess interactions with the ER and prognosis. The splice variant could be detected in all of the cases examined, with high ratios of variant:full-length ARNT (> or =10) characterized in 10 cases. When the patient group was split into quartiles by increasing splice variant ratios, there was an inverse relationship of ER status to ARNT splice-variant ratios (P = 0.01, chi(2)). Univariate analysis showed that cases with high ARNT splice-variant ratios > or =10 had a worse relapse-free and overall survival (P > or = 0.03; hazard ratio, 2.7; and P = 0.006; hazard ratio, 3.9, respectively). In multivariate analysis for relapse-free and overall survival, ARNT splice-variant ratio was the strongest independent factor and, although inversely related to ER, remained a separate risk factor. At least two potential mechanisms could explain this phenomenon: the loss of aryl hydrocarbon receptor-mediated antiestrogenic activity or the blockade of a proapoptotic pathway induced by hypoxia. Because several enzymes involved in drug resistance are induced through a xenobiotic response element, the tumors presenting high ARNT splice-variant ratios may be specifically targeted by drugs normally degraded or inactivated. This study shows the biological importance of ARNT splice variants in the behavior of human breast cancer and suggests that the breast cell lines in which the splice variant was discovered may be useful models for further investigation.

Adult↗
PubMed2001

Dissemination of heart health promotion: lessons from the Canadian Heart Health Initiative Ontario Project.

Situated in central-eastern Canada, Ontario is the largest province with a population of 11 million. Ontario is considered a fairly rich province at the centre of Canada's manufacturing and financial sectors. Public health services in Ontario are primarily delivered through public health departments, each administered by a local board of health and regulated by provincial legislation and program guidelines. The Canadian Heart Health Initiative Ontario Project (CHHIOP) was a four year project (1994 to 1998) undertaken as part of the dissemination phase of the Canadian Heart Health Initiative (CHHI) (see O'Loughlin et al., p.4). CHHIOP is one component of a long-term process to develop and implement effective heart health programs in Ontario.

Canada↗
PubMed2001

Failure of blue-tinted lenses to change reading scores of dyslexic individuals.

BACKGROUND: This study was designed to address a perceived major flaw in past studies investigating tinted lenses and dyslexia; i.e., the lack of a direct, scientifically validated means of diagnosing the type and severity of dyslexia. METHODS: Sixteen 5th and 8th grade students, found to be dyslexic based on testing via the Dyslexia Determination Test (DDT), were randomly divided into two groups of eight. One group was tested first with blue filters (then, 2 to 5 weeks later, no filters) using the Gates MacGinitie Reading Test for reading comprehension. The other group of eight was tested in the same way, first with no filters, then 2 to 5 weeks later with blue filters. The grade level of the test used for each subject was in accord with the DDT decoding level. RESULTS: There was no significant difference in reading comprehension level or reading speed when the blue filter condition was compared to the no filter condition. CONCLUSIONS: Using DDT classification, subjects were found to have mostly dysphoneidetic (mixed pattern) dyslexia. Among this population of dyslexic students, tinted lenses appeared to provide no beneficial effect. We offer an explanation based on neuro-anatomical relationships between the visual system and reading centers in the brain. The hypothesis states that the transient system defect may be an epiphenomenon, which can coincidentally occur in cases of reading disability.

Adolescent↗
PubMed2000

Cofactor recycling with immobilized heterologous cytochrome P450 105D1 (CYP105D1).

Immobilisation of cells and enzymes can be a convenient and rapid way for testing and transforming substances. Cytochromes P450 may be useful in numerous biotransformations of varied lipophilic substrates, performing both regio- and stereo-specific monooxygenation reactions. However, one limitation of their use in vitro is the requirement of cofactor for the supply of electrons in the catalytic cycle. Here we report CYP105D1 from Streptomyces griseus expressed in Escherichia coli can be immobilised from cell-free extracts using DE52, that the immobilised protein is active in bioconversions and that a requirement for cofactor can be sustained by a recycling system for NADH regeneration.

Bacterial Proteins↗
PubMed2000

High-tech software sleuthing. New computer tools give government tighter handle on hard-to-track healthcare fraud.

After developing new data-mining techniques, the government no longer needs to rely on outdated methods when investigating allegations of hard-to-track healthcare fraud. Today, federal officials, such as U.S. Deputy Attorney General Eric Holder Jr. (left), have an enhanced ability to collect and analyze massive amounts of financial and medical information necessary to successfully prosecute perpetrators of crimes that drain the Medicare program.

Aged↗
PubMed2000

Mental stress induces transient endothelial dysfunction in humans.

BACKGROUND: Mental stress has been linked to increased morbidity and mortality in coronary artery disease and to atherosclerosis progression. Experimental studies have suggested that damage to the endothelium may be an important mechanism. METHODS AND RESULTS: Endothelial function was studied in 10 healthy men (aged 50. 4+/-9.6 years) and in 8 non-insulin-dependent diabetic men (aged 52. 0+/-7.2 years). Brachial artery flow-mediated dilation (FMD, endothelium dependent) and response to 50 microg of sublingual glyceryl trinitrate (GTN, endothelium independent) were measured noninvasively by use of high-resolution ultrasound before and after (30, 90, and 240 minutes) a standardized mental stress test. The same protocol without mental stress was repeated on a separate occasion in the healthy men. In healthy subjects, FMD (5.0+/-2.1%) was significantly (P:<0.01) reduced at 30 and 90 minutes after mental stress (2.8+/-2.3% and 2.3+/-2.4%, respectively) and returned toward normal after 4 hours (4.1+/-2.0%). Mental stress had no effect on the response to GTN. In the repeated studies without mental stress, FMD did not change. The diabetic subjects had lower FMD than did the control subjects (3.0+/-1.5% versus 5.0+/-2.1%, respectively; P:=0.02) but showed no changes in FMD (2.7+/-1.1% after 30 minutes, 2.8+/-1.9% after 90 minutes, and 3.1+/-2.3% after 240 minutes) or GTN responses after mental stress. CONCLUSIONS: These findings suggest that brief episodes of mental stress, similar to those encountered in everyday life, may cause transient (up to 4 hours) endothelial dysfunction in healthy young individuals. This might represent a mechanistic link between mental stress and atherogenesis.

Adult↗