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Biomedical subjects

G Bell

Publications and source records attributed to G Bell.

At least 73 records · Page 4Linked to original sources
PubMed1996

Incidence and nature of bile duct injuries following laparoscopic cholecystectomy: an audit of 5913 cases. West of Scotland Laparoscopic Cholecystectomy Audit Group.

The rapid introduction of laparoscopic cholecystectomy has been associated with an apparently increased incidence of bile duct injury which has provoked worldwide concern. The true incidence and mechanism of iatrogenic ductal injury during the development of this procedure remain unclear. To assess this, the introduction of laparoscopic cholecystectomy in the West of Scotland has been audited prospectively over a 5-year period. All cases of biliary ductal injury have been independently reviewed. Some 48 surgeons undertaking laparoscopic cholecystectomy in 19 hospitals submitted prospective data between September 1990 and September 1995. A total of 5913 laparoscopic cholecystectomies were attempted with 98.3 per cent completion of data collection. During this period 37 laparoscopic bile duct injuries occurred. The annual incidence peaked at 0.8 per cent and has fallen to 0.4 per cent in the final year of audit. Injuries occurred after a median personal experience of 51 (range 3-247) laparoscopic cholecystectomies in 22 surgeons. Major bile duct injuries occurred in 20 of 37 patients, giving an incidence of 0.3 per cent. Five mechanisms for laparoscopic ductal injury were identified, including tenting, confluence and diathermy injuries as well as the classical and variant classical types. Ductal injuries were discovered at operation in 18 patients with consequent repair giving a good clinical outcome in 17. Contributory factors (severe inflammation, aberrant anatomy and poor visualization) were present in only 13 of 37 cases. This audit suggests that, at least in the introductory period, laparoscopic cholecystectomy is associated with an overall bile duct injury rate higher than that reported previously after open cholecystectomy, although the incidence of major ductal injury is similar. The late downward trend in bile duct injury, however, suggests there may be a prolonged learning curve for this procedure. Improved understanding of the mechanism of injury may lead to yet further reductions in this complication.

Bile Ducts↗
PubMed1996

Sex and the spread of retrotransposon Ty3 in experimental populations of Saccharomyces cerevisiae.

Mobile genetic elements may be molecular parasites that reduce the fitness of individuals that bear them by causing predominantly deleterious mutations, but increase in frequency when rare because transposition increases their rates of transmission to the progeny of crosses between infected and uninfected individuals. If this is true, then the initial spread of a mobile element requires sex. We tested this prediction using the yeast retrotransposon Ty3 and a strain of Saccharomyces cerevisiae lacking Ty3. We infected replicate isogenic sexual and asexual populations with a galactose-inducible Ty3 element at an initial frequency of 1%. In two of six asexual populations, active Ty3 elements increased in frequency to 38 and 86%, due to the spread in each population of a competitively superior mutant carrying a new Ty3 insertion. Ty3 frequencies increased above 80% in all sexual populations in which transposition was induced in haplophase or in diplophase. Ty3 did not increase in frequency when active during both haplophase and diplophase, apparently because of selective sweeps during adaptation to galactose. Repressed Ty3 elements spread in sexual populations, by increasing sexual fitness. These results indicate that active Ty3 elements are more likely to become established in sexual populations than in asexual populations.

Crosses, Genetic↗
PubMed1996

Concentration of blood lead and ethnicity in the United Kingdom.

The relation between concentration of blood lead and ethnic background in 779 children was examined with the analytical results from the trace element service at the Medical Toxicology Unit (MTU), Guy's and St Thomas's Hospital Trust for the period 1980-94. The ethnic identity was determined with the first and the second names of the investigated subjects. Of the patients of European origin (European) studied 72.8% v only 50.6% of the children with origins in the Indian subcontinent (Asian) had a concentration of blood lead < 100 micrograms/l. The percentage of subgroups with concentrations above the upper acceptable limit of 200 micrograms/l was significantly higher in Asian subjects (European 5% v Asian 26.5%), with the most pronounced difference in those with concentrations of blood lead of 500 micrograms/l (European 0.8% v Asian 10.5%). This study shows that a correlation exists between Asian ethnic background and concentration of blood lead in children. Factors such as cultural habits-for example, use of traditional remedies, cosmetics, diet- and socioeconomic status, may have contributed to this results.

Asia↗
PubMed1995

Shoulder abduction strength measurement in football players: reliability and validity of two field tests.

Musculoskeletal and neurologic injuries affecting shoulder strength are common in contact sports. Full-strength recovery is desired before resumption of competition. On-field assessment of shoulder strength is usually done by manual muscle testing, which lacks sensitivity and reliability. Our objective was to determine the reliability and validity of two field instruments capable of quantifying shoulder abduction strength. Twenty junior football players underwent bilateral isokinetic (60 degrees/s) and isometric shoulder abduction strength measurements using a Cybex 340 isokinetic dynamometer. Test-retest measurements of both shoulders of each player were made using strain gauge (SG) and handheld dynamometer (HHD) instruments. Players were tested during rested and competition conditions. Within and between session reliabilities were calculated using the intraclass coefficient, and validity was assessed using Pearson's correlation coefficient. Overall reliability for each device was calculated using Lisrel analysis. SG was found to be superior to HHD in overall reliability and validity. Within-session reliability in the rested and competition states was 0.75 and 0.78, respectively, for SG and 0.60 and 0.81, respectively, for HHD. Between-session reliability in the rested and competition states dropped to 0.51 and 0.63, respectively, for SG and 0.55 and 0.70, respectively, for HHD. Validity was 0.41 and 0.70 for SG when correlated with Cybex at 0 degree and 60 degrees/s respectively. Validity for HHD was 0.28 and 0.42 for Cybex speeds of 0 degree and 60 degrees/s, respectively. SG reliability and validity were similar when testing was done one shoulder at a time or both shoulders concurrently.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Human fiber size and enzymatic properties after 5 and 11 days of spaceflight.

Biopsies from the vastus lateralis muscle were obtained from three astronauts before and after two 5-day flights and from five astronauts before and after one 11-day flight (space shuttle flights: STS-32, -33, and -34). Muscle fibers from two separate samples from each biopsy were classified as type I and II or as type I, IIA, and IIB by using qualitative myofibrillar adenosinetriphosphatase (ATPase) staining. Cross-sectional area (CSA), number of capillaries per fiber, and the activities of succinate dehydrogenase (SDH), alpha-glycerophosphate dehydrogenase (GPD), and myofibrillar ATPase were determined from one sample of fibers of each myofibrillar ATPase type. Postflight biopsies had 6-8% fewer type I fibers than preflight. Mean fiber CSAs were 16-36% smaller after the 11-day flight with the relative effect being type IIB > IIA > I. Mean fiber CSAs were 11 and 24% smaller in type I and II fibers after 5 days of flight. Myofibrillar ATPase activities increased in type II but not in type I fibers after flight, whereas SDH activity was unaffected in either fast or slow fibers. GPD activity in type I fibers was approximately 80% higher (P > 0.05) postflight compared with preflight. Myofibrillar ATPase/SDH ratios in type II fibers were higher after than before flight, suggesting that some fast fibers were more susceptible to fatigue after flight. The GPD/SDH ratios were elevated in some type I fibers after spaceflight. The number of capillaries per fiber was 24% lower after than before flight, whereas the number of capillaries per unit CSA of muscle tissue was unchanged. These data suggest that adaptations in the size, metabolic properties, and vascularity of muscle fibers can occur rapidly in the space environment. These adaptations were qualitatively similar to those observed in animals after actual or simulated spaceflight conditions for short periods.

Adenosine Triphosphatases↗
PubMed1995

Prophylactic ankle bracing vs. taping: effects on functional performance in female basketball players.

Ankle support devices are commonly used for prevention and treatment of ankle injury, but the effect of these on sport performance has not been evaluated. The purpose of this study was to evaluate the effect of different ankle support devices on four basketball-related performance tests. Eleven female basketball players underwent four performance tests (vertical jump, jump shot, sprint drill, and submaximal treadmill run) while wearing five different types of ankle support on both ankles (no support, tape, Swede-O-Universal, Active Ankle, and Aircast). Ankle support effect on overall performance was assessed using Friedman's analysis of variance (ANOVA) by ranks and on specific performance parameters using one-way ANOVA for repeated measures. Overall performance was impaired by ankle support. The Active Ankle brace impaired performance the least out of the support devices. Vertical jump was less with ankle tape as compared with no tape (p < .05), whereas jump shot accuracy was better with tape as compared with the Swede-O-Universal (p < .05). Oxygen consumption (VO2) and energy expenditure were higher with the Aircast as compared with tape (p < .05). It was concluded that the use of ankle support by female basketball players does adversely affect basketball-related performance tests, and the prophylactic benefit of bracing needs to be weighed against performance impairment.

Adolescent↗
PubMed1994

Evaluation of the cost of laparoscopic and open cholecystectomy.

Despite the rapid growth of laparoscopic cholecystectomy, the comparative costs of this new procedure and open cholecystectomy remain unknown. In this study the costs have been evaluated of a consecutive series of patients undergoing these procedures in a district general hospital with an established resource management centre. Fifty consecutive patients undergoing open cholecystectomy between June 1988 and July 1990 immediately before the introduction of laparoscopic cholecystectomy and 100 patients undergoing laparoscopic cholecystectomy between August 1990 and June 1992 were studied. Costs estimated prospectively for each patient were compared. The mean cost per patient of open cholecystectomy was estimated at 2102 pounds compared with 2026 pounds for the first 50 patients undergoing the laparoscopic procedure. The mean cost (1744 pounds) for the second 50 patients undergoing laparoscopic cholecystectomy was less than that for either open cholecystectomy (P < 0.005) or the initial 50 laparoscopic operations (P < 0.03). Operating theatre costs and equipment costs were higher in both laparoscopic groups. These were offset by the higher nursing and ward costs of open cholecystectomy. For the laparoscopic procedure the operating theatre times and duration of hospital stay were both less in the second 50 patients than in the first 50. After the initial learning period, laparoscopic cholecystectomy is less expensive than the open operation and represents a cost-effective method for treatment of the patient with gallstones.

Adult↗
PubMed1994

Distribution of kappa opioid receptor mRNA in adult mouse brain: an in situ hybridization histochemistry study.

The distribution of the kappa opioid receptor mRNA in adult mouse brain has been determined using the technique of in situ hybridization histochemistry. The mRNA for the kappa opioid receptor was expressed in distinct areas throughout the brain. The telencephalon showed high levels of expression in the deeper layers of the parietal and temporal cortex, olfactory tubercle, nucleus accumbens, claustrum, endopiriform nucleus, nucleus of the vertical and horizontal limb of the diagonal band, and medial and central nuclei of the amygdala. In the diencephalon, kappa opioid receptor mRNA was present in multiple medial thalamic nuclei including the centromedial, paraventricular, parafasicular, central, and peritenial nuclei, as well as in most hypothalamic nuclei including the ventromedial, periventricular, supraoptic, arcuate, and dorsomedial nuclei. The mesencephalon showed highest levels of kappa receptor mRNA in the substantia nigra pars compacta, ventral tegmental area, zona incerta, interpeduncular nucleus, superior colliculus, inferior colliculus, central grey, and the raphe nucleus. In the metencephalon, kappa opioid receptor mRNA was expressed in the parabrachial nuclei, locus coeruleus, dorsal and ventral tegmental nuclei, and the raphe pontine nuclei. The distribution of the kappa receptor mRNA closely coincides with the localization of binding sites in rat brain for [3H]U-69,593, a specific kappa 1 opioid receptor ligand. The mRNA distribution also correlates with neuroanatomical sites of actions of kappa agonists and distribution of the endogenous kappa receptor ligand dynorphin.

Animals↗
PubMed1994

Prospective audit of the introduction of laparoscopic cholecystectomy in the west of Scotland. West of Scotland Laparoscopic Cholecystectomy Audit Group.

Although laparoscopic cholecystectomy has rapidly developed in the treatment of gall bladder disease in the absence of controlled clinical trial data its outcome parameters compared with open cholecystectomy remain unclear. A prospective audit of the introduction of laparoscopic cholecystectomy in the west of Scotland over a two year period was carried out to attempt to assess this new procedure. A total of 45 surgeons in 19 hospitals performing laparoscopic cholecystectomy submitted prospective data from September 1990-1992. A total of 2285 cholecystectomies were audited (a completed data collection rate of 99%). Laparoscopic cholecystectomy was attempted in 1683 (74%) patients and completed in 1448 patients (median conversion rate to the open procedure 17%). The median operation time in the completed laparoscopic cholecystectomy patients was 100 minutes (range 30-330) and overall hospital stay three days (1-33). There were nine deaths (0.5%) after laparoscopic cholecystectomy although only two were directly attributable to the laparoscopic procedure. In the laparoscopic cholecystectomy group there were 99 complications (5.9%), 53 (3%) of these were major requiring further invasive intervention. Forty patients (2.4%) required early or delayed laparotomy for major complications such as bleeding or bile duct injuries. There were 11 (0.7%) bile duct injuries in the laparoscopic cholecystectomy series, five were noted during the initial procedure and six were recognised later resulting from jaundice or bile leaks. Ductal injuries occurred after a median of 20 laparoscopic cholecystectomies. In conclusion laparoscopic cholecystectomy has rapidly replaced open cholecystectomy in the treatment of gall bladder disease. Although the overall death and complication rate associated with laparoscopic cholecystectomy is similar to open cholecystectomy, the bile duct injury rate is higher.

Adolescent↗
PubMed1994

Prediction of stroke volume from oxygen pulse measurements in untrained and trained men.

This study examined the relationship of oxygen pulse (O2 pulse) to stroke volume (SV) and arterio-venous oxygen difference [(a-v)O2 diff] during submaximal cycle exercise in untrained (UG) and trained (TG) males. Fourteen volunteers in each group completed an incremental VO2 max test and a submaximal test at 60% VO2 max to determine cardiac output (Q) via CO2 rebreathing. VO2, Q, and heart rate (HR) were used to calculate SV and (a-v)O2 diff. There were no significant differences (p > .05) between the two groups for O2 pulse, SV, and (a-v)O2 diff during submaximal exercise. Stroke volume index (SVI) was significantly higher (p < .05) in the TG. O2 pulse was significantly related to SV and SVI (p < .05) but not to (a-v)O2 diff in both groups. Regression equations for predicting SV from O2 pulse for UG and TG were Y = 6.81X + 26.7, SE = 21.4, r = 0.84, and Y = 10.33X - 32.3, SE = 14.2, r = 0.71, respectively. These results suggest that O2 pulse can be used to predict SV during submaximal cycle exercise in untrained and trained men.

Adult↗
PubMed1994

Health reform in Saskatchewan.

This paper describes the direction of health reform taking place in Saskatchewan. The rationale underlying the shift to a needs-driven, outcome-oriented, locally controlled health system is discussed. This shift is in concert with nationally recognized directions in improving health status, maintaining standards, ensuring a more cost-effective system, and providing a continuum of services characterized by a shift from institutional to community-based services, health-related public policy and health promotion. Included is a discussion of the process of change and some of the elements of the newly constituted delivery system, such as district boards, needs assessment, core services, and provincial components such as the Health Services Utilization Review Commission and the Provincial Health Council. Some implications for issues such as stroke prevention are noted.

Cerebrovascular Disorders↗
PubMed1993

Pathogen evolution within host individuals as a primary cause of senescence.

This paper discusses a novel theory of senescence: the community of pathogens within each host individual evolves during the life-time of the host, and in doing so progressively reduces host vigour. I marshal evidence that asymptomatic host individuals maintain persistent populations of viral pathogens; that these pathogens replicate; that they are often extremely variable; that selection within hosts causes the evolution of pathogens better able to exploit the host; that selection is host-specific; and that such evolving infections cause appreciable and progressive deterioration. Experimental approaches to testing the theory are discussed.

Aging↗