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Biomedical subjects

B Walsh

Publications and source records attributed to B Walsh.

At least 19 recordsLinked to original sources
PubMed1999

Mitochondrial function in human skeletal muscle is not impaired by high intensity exercise.

The hypothesis that high-intensity (HI) intermittent exercise impairs mitochondrial function was investigated with different microtechniques in human muscle samples. Ten male students performed three bouts of cycling at 130% of peak O2 consumption (V.O2,peak). Muscle biopsies were taken from the vastus lateralis muscle at rest, at fatigue and after 110 min recovery. Mitochondrial function was measured both in isolated mitochondria and in muscle fibre bundles made permeable with saponin (skinned fibres). In isolated mitochondria there was no change in maximal respiration, rate of adenosine 5'-triphosphate (ATP) production (measured with bioluminescence) and respiratory control index after exercise or after recovery. The ATP production per consumed oxygen (P/O ratio) also remained unchanged at fatigue but decreased by 4% (P<0.05) after recovery. In skinned fibres, maximal adenosine 5'-diphosphate (ADP)-stimulated respiration increased by 23% from rest to exhaustion (P<0.05) and remained elevated after recovery, whereas the respiratory rates in the absence of ADP and at 0.1 mM ADP (submaximal respiration) were unchanged. The ratio between respiration at 0.1 and 1 mM ADP (ADP sensitivity index) decreased at fatigue (P<0.05) but after the recovery period was not significantly different from that at rest. It is concluded that mitochondrial oxidative potential is maintained or improved during exhaustive HI exercise. The finding that the sensitivity of mitochondrial respiration to ADP is reversibly decreased after strenuous exercise may indicate that the control of mitochondrial respiration is altered.

Adenosine Diphosphate↗
PubMed1999

Outbreak of hepatitis B in an acupuncture clinic.

A retrospective cohort serological study identified five confirmed cases of acute hepatitis B virus (HBV) infection in three and a half years at an acupuncture clinic in London. These cases made up 1.7% of those treated by an acupuncturist who was a hepatitis B 'e' antigen (HBeAg) carrier. Virus subtyping and polymerase chain reaction--single strand conformation polymorphism assay (PCR-SSCPA) showed that strains of virus from the acupuncturist and two of the five patients for whom it was possible to perform the test were indistinguishable. Nine other patients who attended the same acupuncturist had antibody to the hepatitis B core antigen but had other risk factors for HBV infection. No obvious mode of transmission was identified but cross contamination of needles could not be ruled out in two cases. The fifth case was exposed to HBV after disposable needles were introduced. Routine immunisation of acupuncturists against HBV is recommended.

Acupuncture Therapy↗
PubMed1998

Evidence for the continuity of early problem behaviors: application of a developmental model.

Evidence of the continuity of early problem behaviors in young girls and boys was examined developmentally. Data were gathered on 104 mother-child dyads from low-income families when children were between 1 and 5 years of age. Difficult temperament, aggression, and noncompliance from 12 to 24 months, and externalizing and internalizing problems at 36 and 60 months, were assessed. The results provide evidence for the continuity of early behavioral and emotional problems and support for the early differentiation between internalizing and externalizing problems. Implications of the current findings for prevention efforts are presented.

Aggression↗
PubMed1998

Long-term in vivo cochlear transgene expression mediated by recombinant adeno-associated virus.

Adeno-associated virus (AAV) integrated transgene expression within guinea pig cochlea has been previously documented. This article extends these studies by characterizing the AAV-mediated gene transfer for duration of transgene expression within the cochlea and its effect upon cochlear cytoarchitecture over a period of 6 months. All animals infused with AAV expressed the transgene product, bacterial beta-galactosidase (beta-gal) enzyme, in the spiral limbus, spiral ligament, spiral ganglion cells and the organ of Corti at 2-24 weeks after infusion. However, the level of beta-gal expression, as determined from intensity of immunoreactivity, was relatively lower at 24 weeks as compared with 2 weeks. The cellular and tissue architecture within the AAV-beta-gal perfused cochleae, harvested 2-8 weeks after AAV infusion, was generally intact, ie free from inflammation and cellular degeneration. However, cellular degeneration and degradation was apparent in the cochleae of some but not all animals harvested at 12 and 24 weeks after AAV infusion.

Animals↗
PubMed1998

Effects of estrogen replacement therapy on the lipoprotein profile in postmenopausal women with ESRD.

BACKGROUND: Patients with ESRD have excessive cardiovascular morbidity and mortality. In postmenopausal women with normal renal function, estrogen replacement therapy decreases cardiovascular mortality by 50%, in part because of their beneficial effects on the lipoprotein profile. Because of similarities in the lipoprotein profile between healthy, postmenopausal women, and women with ESRD, we examined the effects of estrogen replacement on lipoproteins in 11 postmenopausal women with ESRD. METHODS: In a randomized, placebo-controlled crossover study (8 week treatment arms) using 2 mg daily of oral, micronized estradiol, 11 postmenopausal women with ESRD were treated. Neither baseline lipid nor lipoprotein abnormalities were used as entry criteria for study participation. RESULTS: Blood estradiol levels were 19 +/- 4 with placebo and 194 +/- 67 pg/ml (P = 0.024) with estradiol treatment. Total HDL cholesterol concentrations increased from 52 +/- 19 mg/dl to 61 +/- 20 mg/dl (16%), with placebo and estradiol treatments, respectively (P = 0.002). Apolipoprotein A1 increased by 24.6% (P = 0.0002) with estradiol intervention. HDL2 concentrations were 19 +/- 13 with placebo and 24 +/- 16 with estradiol treatment (P = 0.046). There were no differences in total or LDL cholesterol, other lipoprotein fractions including Lp(a), and triglycerides with 2 mg daily estradiol treatment. No significant side effects were observed. CONCLUSIONS: Therefore, using standard dosage regimens for estrogen replacement therapy in postmenopausal women with ESRD, HDL cholesterol is increased to an extent that would be expected to improve their cardiovascular risk profile. Further studies are needed to assess whether estrogen replacement therapy decreases the incidence or severity of cardiovascular disease in ESRD patients to a similar degree compared with other women.

Cardiovascular Diseases↗
PubMed1998

Arthritis and HLA-B27 in native North American tribes.

Whereas it is clear that HLA-B27 is increased in many North American natives, the prevalence varies a great deal. There is still a paucity of data on a large number of tribes. There is, however, a suggestion that HLA-B27 positive prevalence follows cultural/linguistic groupings. Reactive arthritis, sacroiliitis, and ankylosing spondylitis also appear to be increased in these people, but their relationship to HLA-B27 and possibly additional genetic predisposing factors is far from clear. Given these data and the known association of infectious agents, more extensive studies are warranted, especially in those tribes with a large enough population to achieve statistical significance.

Arthritis↗
PubMed1997

DSM-III-R disorders in preschool children from low-income families.

OBJECTIVE: To generate rates of DSM-III-R disorders in a sample of preschool children from low-income families, examine impairment ratings for preschool children meeting criteria for DSM-III-R disorders, and compare rates of psychopathology using DSM-III-R criteria with rates generated by the Child Behavior Checklist (CBCL). METHOD: As part of an ongoing longitudinal study of 104 mother-child dyads from low-income families, data were gathered when children were 5 years of age. DSM-III-R disorders were diagnosed through the administration of the Schedule for Affective Disorders and Schizophrenia for School-Age Children to the mothers, and mothers competed the CBCL. RESULTS: Rates of DSM-III-R disorders among preschool children from low-income families were higher than those reported in community samples, but comparable with rates for low-income school-age children and adolescents. Children meeting criteria for DSM-III-R disorders were rated as significantly impaired. The prevalence of behavioral and emotional problems was similar by both DSM-III-R criteria and the CBCL. There was some evidence, however, that the two systems identified different children. CONCLUSIONS: DSM-III-R criteria appear to adequately identify preschool children with serious behavioral and emotional problems. Longitudinal studies are needed to explore further the relative utility of the DSM and CBCL in the identification of psychopathology in preschool children.

Chi-Square Distribution↗
PubMed1997

Classification of mild Alzheimer's disease by artificial neural network analysis of SPET data.

An evaluation of the performance of artificial neural networks (ANNs) for the classification of probable Alzheimer's disease (pAD) patients was undertaken using data extracted from four regions of interest constructed on single photon emission tomographic (SPET) cerebral perfusion images. Two studies using feed-forward neural networks (FFNNs) were undertaken. The first was to determine if it would be possible to classify pAD patients and normal subjects in a mixed group, comprising 29 patients diagnosed as having pAD varying in severity from mild, established dementia to moderate dementia and 10 healthy control subjects. The second was to determine if the networks generated in the first study could prospectively classify 15 additional patients with very mild or mild cognitive impairment. The results were compared to those obtained using the same data and discriminant analysis. The relative performances of the two analysis techniques were assessed on the basis of the area under receiver operating characteristics (ROC) curves. The FFNN successfully classified all datasets in the first study, achieving an area under the ROC curve of 1.00, whereas discriminant analysis achieved 0.94. When tested on data from the second group, the areas under the ROC curves varied between 0.86 and 1.00 for the FFNN, whereas that for discriminant analysis was 0.99. We conclude that FFNNs can accurately classify pAD patients with mild to moderate dementia using data obtained from SPET cerebral perfusion images.

Aged↗
PubMed1997

Trends in alcohol production, trade and consumption.

This paper is a survey of the structure and significance of international trade in alcoholic beverages in the contemporary world economy. It presents data on the level of trade in the main alcoholic beverages for the period since 1970. The constant-dollar value of this trade grew by a factor of 2.1 between 1975 and 1992. It represents approximately one half of the one per cent of the value of world trade in all commodities. This proportion has remained very stable over the past 20 years. International trade in beer, wine and spirits has greatly extended the range of alcoholic beverages available around the world and reduced their cost. It has played a large part in the tendency for convergence in the patterns of alcohol consumption, as countries diversify away from their dependence on locally produced beverages. Traditional spirits-drinking and beer-drinking countries have witnessed very rapid increases in the consumption of wine, while heavy wine drinking countries have seen rapid growth of the consumption of beer. While imported beverages remain relatively unimportant in total consumption of alcoholic beverages, they have played a significant role in the growth and diversification of alcohol consumption in many countries.

Alcohol Drinking↗
PubMed1996

Preharvest food safety.

Preharvest food safety is essential for the protection of our food supply. The production and transport of livestock and poultry play an integral part in the safety of these food products. The goals of this safety assurance include freedom from pathogenic microorganisms, disease, and parasites, and from potentially harmful residues and physical hazards. Its functions should be based on hazard analysis and critical control points from producer to slaughter plant with emphasis on prevention of identifiable hazards rather than on removal of contaminated products. The production goal is to minimize infection and insure freedom from potentially harmful residues and physical hazards. The marketing goal is control of exposure to pathogens and stress. Both groups should have functional hazard analysis and critical control points management programs which include personnel training and certification of producers. These programs must cover production procedures, chemical usage, feeding, treatment practices, drug usage, assembly and transportation, and animal identification. Plans must use risk assessment principles, and the procedures must be defined. Other elements would include preslaughter certification, environmental protection, control of chemical hazards, live-animal drug-testing procedures, and identification of physical hazards.

Abattoirs↗
PubMed1995

Arterial closing pressure correlates with diastolic pseudohypertension in the elderly.

BACKGROUND: Pseudohypertension has frequently been reported in the elderly population, with the diastolic measurement being the most frequent source of error. There is no satisfactory noninvasive method of calculating the error in the blood pressure reading. We investigated the role of arterial closing pressure in the diagnosis of diastolic pseudohypertension. METHODS: Indirect and direct blood pressure were measured in 24 elderly patients. Brachial artery closure was visualized by ultrasound in all subjects. Arterial closing pressure (ACP) was recorded as zero if the vessel was seen to close spontaneously when it was isolated from central arterial pressure. If the vessel did not close spontaneously, a water cuff was applied externally over the artery and the additional pressure required to close it was recorded. RESULTS: Diastolic pseudohypertension was noted in 8 subjects. Spontaneous closure of the brachial artery occurred in the 16 without pseudohypertension; i.e., ACP = 0. Additional pressure of the water cuff (range: 30-158 mm Hg) was required to collapse the artery (ACP) in those with diastolic pseudohypertension. ACP correlated with the extent of diastolic pseudohypertension (range: 5-17 mm Hg); r = .85, p < .001). CONCLUSION: We propose that ACP may be used to diagnose the presence and extent of pseudohypertension.

Aged↗