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Biomedical subjects

G Taylor

Publications and source records attributed to G Taylor.

At least 163 records · Page 9Linked to original sources
PubMed1997

Oesophageal motor responses to gastro-oesophageal reflux in healthy controls and reflux patients.

AIMS: To compare oesophageal motor responses to gastro-oesophageal reflux (GOR) in 16 healthy controls (group 1) and 25 reflux patients, 15 without (group 2) and 10 with (group 3) oesophagitis. METHODS: All subjects underwent 24 hour ambulatory oesophageal pH measurements (5 cm above the lower oesophageal sphincter (LOS)) combined with pressure monitoring (5, 10, and 15 cm above the LOS for oesophageal body motility and 27 cm above the LOS for voluntary swallow detection). Contraction patterns (peristaltic, simultaneous, isolated, mixed type, and non-transmitted swallows) and peristaltic contraction wave characteristics (amplitude, duration, and velocity) during GOR were compared in the three groups. RESULTS: The average number of motor activities per minute was significantly higher in group 1 (p < 0.05). In all groups, the most common motor contraction pattern was peristaltic. The percentage of peristaltic activity per subject was significantly higher in group 1 (p < 0.05). There were no significant differences in other contraction patterns among the three groups (p > 0.05). Of the peristaltic contraction wave characteristics there were no significant differences in any parameters (amplitude, duration, and velocity) among the three groups (p > 0.05). The average pH increment in response to motor activities was significantly higher in group 1 (p < 0.05). CONCLUSIONS: Motor responses to GOR were found to be predominantly primary peristaltic in all groups. During GOR, reflux patients have less frequent activity, a smaller proportion of activity is peristaltic, and the average pH increment in response to motor activities is reduced compared with controls.

Adult↗
PubMed1997

Providing high-quality care for children.

Because home care traditionally has served older patients under Medicare, some providers tend to treat in-home pediatric patients like "little adults." To offer children and their families the specialty care that they require and deserve, one agency limits its services exclusively to pediatrics.

Child↗
PubMed1997

Use of a generic polymerase chain reaction assay detecting human T-lymphotropic virus (HTLV) types I, II and divergent simian strains in the evaluation of individuals with indeterminate HTLV serology.

In countries with a low prevalence of human T-lymphotropic virus (HTLV) infection, indeterminate HTLV serologies are a major problem in blood bank screening because of the uncertainties about infection in these cases. The recent discovery of two new types of simian T-lymphotropic viruses (STLV), which give an HTLV-indeterminate serology, raises the question whether indeterminate serologies in humans may be linked to new types of HTLV. Starting from a Tax sequence alignment of all available primate T-cell lymphotropic virus strains (PTLV), including the two new types STLV-PH969 and STLV-PP1664, we developed generic and type-specific nested polymerase chain reactions (PCRs). The generic PCR proved to be highly sensitive and cross-reactive for all four types of PTLV, while the discriminatory PCRs had a high sensitivity and a specificity of 100%. There was no cross-reactivity with human immunodeficiency virus (HIV), ensuring correct interpretation of results from coinfected patients. Among the 77 serologically indeterminate samples tested, 6 were found to be HTLV-1 PCR positive and 1 was HTLV-II PCR positive. Sequencing of one of the HTLV-I PCR positives excluded PCR contamination, and revealed a divergent type of HTLV-I. The majority of the seroindeterminate samples (91%) were however HTLV-PCR negative, and no new types of HTLV were found. This new assay can identify otherwise undetected HTLV-I or HTLV-II infections and is a useful tool of screening for new types of HTLV among seroindeterminate samples.

Animals↗
PubMed1997

Jarman underprivileged area scores, tooth decay and the effect of water fluoridation.

OBJECTIVE: To examine the association between dental caries and Jarman underprivileged area scores at regional, district and electoral ward level and explore any possible relationship with water fluoridation. DESIGN: An ecological study using the English results from the NHS dental surveys on 5-year-old children in 1991/2 and 1993/4, and the survey of 12-year-old children in 1992/3. Jarman underprivileged area scores were used from the 1991 census. SETTING: The study used former English health authority regions and districts. The electoral wards were in non-fluoridated Salford and Trafford and Liverpool, and fluoridated Newcastle and North Tyneside. SUBJECTS: The random sample of 5-year-old children examined in 1991/2 and 1993/4, and 12-year-old children in 1992/3, in studies coordinated by the British Association for the Study of Community Dentistry. OUTCOME MEASURES: Correlations between regional, district and electoral ward mean dmft/DMFT and Jarman underprivileged area scores. RESULTS: Significant correlations were demonstrated at a regional level in 5-year-old children in 1991/2, district level in 5-year-old children in 1991/2 and 1993/4 and at electoral ward level in both age groups in 1992/3 and 1993/4. Correlation coefficients varied between r = 0.88 to r = 0.46. Multiple linear regression at electoral ward level showed significant interactions between Jarman scores and water fluoridation. There was an average 44 per cent and 43 per cent reduction in caries in fluoridated electoral wards in 5- and 12-year-old children respectively. In deprived electoral wards, with a Jarman score of 40, the reduction in caries increased to 54 per cent and 56 per cent for 5- and 12-year-old children respectively. CONCLUSIONS: Dental caries was associated with Jarman underprivileged area scores. The differential efficacy of fluoridation to deprived areas was demonstrated at electoral ward level. Water fluoridation was confirmed as an evidence based intervention which has halved the amount of tooth decay in 5- and 12-year-old children.

Child↗
PubMed1997

Screening for fragile X syndrome.

BACKGROUND AND AIM OF REVIEW. In 1991, the gene responsible for fragile X syndrome, a common cause of learning disability, was discovered. As a result, diagnosis of the disorder has improved and its molecular genetics are now understood. This report seems to provide the information needed to decide whether to use DNA testing to screen for the disorder. HOW THE RESEARCH WAS CONDUCTED. A literature search of electronic reference databases of published and 'grey' literature was undertaken together with hand searching of the most recent publications. RESEARCH FINDINGS. NATURAL HISTORY. Physical characteristics of fragile X syndrome include facial atypia, joint laxity and, in boys, macro-orchidism. Most affected males have moderate-to-severe learning disabilities with IQs under 50 whereas most females have borderline IQs of 70-85. Behavioural problems are similar to those seen with autism and attention-deficit disorders. Although fragile X syndrome is not curable there are a number of medical, educational, psychological and social interventions that can improve the symptoms. About 6% of those with learning disabilities tested in institutions have fragile X syndrome. Population prevalence figures are 1 in 4000 in males and 1 in 8000 in females. GENETICS. The disorder is caused by a mutation in a gene on the X chromosome which includes a trinucleotide repeat sequence. The mutation is characterized by hyper-expansion of the repeat sequence leading to down-regulation of the gene. In males an allele with repeat size in excess of 200, termed a full mutation (FM), is always associated with the affected phenotype, whereas in females only half are affected. Individuals with alleles having repeat size in the range 55-199 are unaffected but in females the sequence is heritably unstable so that it is at high risk of expansion to an FM in her offspring. This allele is known as a pre-mutation (PM) to contrast it with the FM found in the affected individual. No spontaneous expansions directly from a normal allele to an FM have been observed. SCREENING STRATEGIES. The principal aims of screenng for fragile X syndrome is to reduce the birth prevalence of the disorder, by prenatal diagnosis and selective termination of pregnancy, or by reducing the number of pregnancies in women who have the FM or PM alleles. Possible screening strategies are: routine antenatal testing of apparently low risk pregnancies, preconceptual testing of young women, and systematic testing in affected families ('cascade' screening). A secondary aim is to bring forward the diagnosis of affected individuals so that they might benefit from early treatment. Active paediatric screening and neonatal screening could achieve this but there is no direct evidence of any great benefit from early diagnosis. SCREENING TESTS. Cytogenetic methods are unsuitable for screening purposes. Southern blotting of genomic DNA can be used but is inaccurate in measuring the size of small PMs, there is a long laboratory turnaround time, and it is relatively expensive. The best protocol is to amplify the DNA using polymerase chain reaction on all samples, and when there is a possible failure to amplify, a Southern blot.(ABSTRACT TRUNCATED)

Costs and Cost Analysis↗
PubMed1996

High activated and memory cytotoxic T-cell responses to HTLV-1 in healthy carriers and patients with tropical spastic paraparesis.

The cytotoxic T-lymphocyte (CTL) response to HTLV-1 is directed mainly against the Tax protein. Circulating, activated Tax-specific CTL can be found in a majority of healthy carriers and patients with the HTLV-1-associated disease tropical spastic paraparesis (HAM/TSP). In this study we present data on the Tax-specific CTL response of 26 HTLV-1 carriers, including 10 newly recruited subjects. Rex-specific CTL were not found in any subjects investigated. Activated and memory CTL responses were determined separately in 4 healthy carriers, 3 HAM/TSP patients, and 1 "seronegative HAM/TSP." In all subjects, the mean frequency of peptide-specific memory cells per epitope (1/1307) was high. There was no significant difference in mean memory CTL frequency per epitope or in the proportion of subjects with activated CTL between healthy carriers and HAM/TSP patients. One individual with HAM/TSP had an unusually high frequency response to two peptides, suggesting immunodominance of epitope recognition in this individual. We conclude that the magnitude and components of the HLTV-1-specific CTL response do not differ between healthy carriers and HAM/TSP patients. These data do not support a specific CTL-mediated component in the pathogenesis of HAM/TSP.

Amino Acid Sequence↗
PubMed1996

Promoting compliance with tuberculosis drug therapy.

The recent increase in the notifications of tuberculosis infections has focused the attention of healthcare professionals on reasons for the disease's resurgence. This article describes how directly observed therapy and an enlightened approach to health promotion for groups of people perceived as being at risk, could prevent further increases in incidence.

Cultural Characteristics↗
PubMed1996

Male reproductive systems under chronic fluoxetine or trimipramine treatment.

Adult male Long-Evans rats (n = 9 per group) received daily exposure for 4 weeks to fluoxetine (0.75 mg FLUOX/kg body weight) or trimipramine (1.6 mg TRIMI/kg body weight). Separate tests of copulation, sexual motivation, and intermale aggressive behaviors were used to evaluate functional changes during chronic exposure to either typical or atypical antidepressant drugs with more or less serotonin specificity. Circulating hormones, primary and secondary sex structures, and concentrations of dopamine (DA) and serotonin (5-HT) from mesolimbic tissue were assessed at necropsy. Results of tests with estrous females and untreated males revealed progressive disruption to sexual performance and aggressive responsiveness over time of treatment with TRIMI and, to a lesser extent, with FLUOX. By contrast, motivation, testosterone, and all measures of reproductive physiology were indistinguishable from controls. Ratios of transmitter metabolites relative to the parent compounds indicated similar reductions of 5-HT turnover with FLUOX and TRIMI. However, influences on DA turnover were significantly less with FLUOX than with TRIMI. Conclusions are that long-term intervention with antidepressant drugs may disrupt sociosexual exchanges without compromising male rats' interest in sexual contact or integrity of their reproductive physiology. Lessened disruption of sociosexual behaviors with this regimen of chronic FLUOX treatment may be related to the greater selectivity on serotonin relative to dopamine turnover.

Adrenal Cortex Hormones↗
PubMed1996

Additive and antagonistic effects of ozone and salinity on the growth, ion contents and gas exchange of five varieties of rice (Oryza sativa L.).

Five varieties of rice (Oryza sativa L.) of varying salinity resistance were grown in non-saline and in saline conditions, with and without a repeated exposure to ozone at a concentration of 83 nmol mol(-1) giving an AOT40 (cumulative exposure above 40 nmol mol(-1)) of 3600 nmol mol(-1) h. Salinity caused a substantial reduction in shoot and root dry weight in all varieties, but the effect on root growth was proportionately less than on shoot growth. Ozone reduced root dry weight but the treatment used did not significantly affect shoot dry weight. Both salinity and ozone reduced plant height. The potassium concentration in the leaves of all five varieties was reduced by salinity, and by ozone in both saline and non-saline treatments. Ozone reduced the sodium concentration in plants grown at 50 mM NaCl but had no effect upon the chloride concentration. Carbon dioxide assimilation, transpiration and stomatal conductance were all reduced by salinity and by ozone and there was close quantitative similarity between the effects of ozone and/or salinity upon assimilation, stomatal conductance and transpiration. There were some antagonistic effects but there were additive effects of salinity and of ozone on root dry weight, plant height, shoot potassium concentration, photosynthesis, transpiration and stomatal conductance. The possible basis of the additive effects of salinity and ozone on gas exchange and mineral uptake are discussed.

Journal Article↗
PubMed1996

Cardioesophageal reflex: a mechanism for "linked angina" in patients with angiographically proven coronary artery disease.

OBJECTIVES: The purpose of this study was to investigate the presence of a cardioesophageal reflex in patients with coronary artery disease that may explain the mechanism of "linked angina." BACKGROUND: It has been previously shown that esophageal acid stimulation can reduce coronary blood flow in patients with syndrome X, suggesting the presence of a cardioesophageal reflex in humans. METHODS: We studied the effect of esophageal acid stimulation on coronary blood flow in 14 patients with angiographically documented significant coronary artery disease and in 18 heart transplant recipients. Hydrochloric acid (0.1 mol/liter) and 0.9% saline solution were infused in random, double-blind manner (60 ml over 5 min) through a fine-bore tube positioned in the patient's distal esophagus, and coronary blood flow measurements were obtained after each infusion by use of a 3.6F intracoronary Doppler catheter positioned in the proximal left anterior descending coronary artery. RESULTS: Coronary blood flow was reduced significantly by esophageal acid stimulation in the coronary artery disease group (before acid 70.4 +/- 14.3 ml/min, after acid stimulation 46.4 +/- 19.1 ml/min [mean +/- SD], p < 0.01). However, there was no significant difference in coronary blood flow during saline infusion (73.5 +/- 15.3 vs. 72.5 +/- 14 ml/min). Coronary blood flow in the heart transplant group was not affected by acid or saline infusion. CONCLUSIONS: Esophageal acid stimulation can cause animal attacks and significantly reduce coronary blood flow in patients with coronary artery disease. The lack of any significant effect in heart transplant recipients with heart denervation suggests a neural reflex.

Aged↗