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Biomedical subjects

A Barker

Publications and source records attributed to A Barker.

At least 55 records · Page 3Linked to original sources
PubMed1994

Identification of VCR, a repeated sequence associated with a locus encoding a hemagglutinin in Vibrio cholerae O1.

We have determined the nucleotide sequence of a 6.3-kb BamHI fragment of the chromosome of Vibrio cholerae 569B that includes the sequence of the mannose-fucose-resistant hemagglutinin reported previously (V.L. Franzon, A. Barker, and P. A. Manning, Infect. Immun. 61:3032-3037, 1993). This region contains nine copies of a 124-bp direct repeat, here named VCR, of imperfect dyad symmetry, that are shown by Southern hybridization to occur at least 60 to 100 times in the V. cholerae O1 chromosome. Large-scale chromosomal mapping suggests that the repeats are confined to about 10% of the chromosome. Related sequences are also found in non-O1 V. cholerae but not in other members of the family Vibrionaceae. However, VCR is unrelated to other previously described repetitive sequences.

Amino Acid Sequence↗
PubMed1994

A comparative study of postgraduate medical education in North East Thames Region.

As a prelude to more detailed formal contracting, North East Thames Region undertook a review to examine whether the content of postgraduate medical education (PGME) varies according to the type of hospital in which junior doctors are trained. The study covered a sample of 83 trainees at different grades in four types of hospital (postgraduate, university, district general hospital involved in off-site undergraduate medical education, and district general hospital with no formal involvement in undergraduate medical education) and was designed as a qualitative comparative study. The results of the study point to a perceived lack of structure in PGME and indicate that hospital type alone does not determine a trainees' PGME experience. Moreover, different training grades have different educational needs, which will need to be addressed under more formal contracting arrangements. The Region plans to take this work forward by convening one or more consensus conferences to examine how a more structured approach to PGME could be implemented.

Attitude of Health Personnel↗
PubMed1994

Seasonal and weather factors in parasuicide.

BACKGROUND: Seasonal variation in suicide and parasuicide has previously been reported. Few investigations have examined whether meteorological factors could influence suicidal behaviour, and the inconclusive results produced may be due to a variety of methodological problems. The present study overcomes some previous difficulties and tested whether parasuicide admission rate is related to weather variables. METHOD: Over 12,000 admissions for parasuicide were analysed by month, season, and in relation to meteorological data, which were measured close to the admitting hospital. RESULTS: Marked seasonal (P < 0.001) and monthly (P < 0.001) variations in mean daily parasuicide numbers were seen in women but not men. Small but highly significant correlations were demonstrated between parasuicide rate and weather parameters (P < 0.01), which were more marked in women (P < 0.01). These effects were additional to the monthly variation (P < 0.05). CONCLUSIONS: Weather has a small influence on parasuicide. Gender differences in body temperature regulation might account for the sex difference seen.

Cross-Sectional Studies↗
PubMed1993

Novel microsurgical model of experimental vascular neointimal hyperplasia.

Neointimal hyperplasia is a common finding after trauma to blood vessels and also as a primary change in atherosclerosis. In this study we have developed a simple model, using microsurgical techniques, for the initiation of neointimal hyperplasia in the rat. In 24 Wistar rats, a 2 mm-diameter arteriotomy in the aorta was repaired with a "patch" of iliolumbar vein, using eight evenly spaced 10-0 Ethilon sutures. The patch overlapped the edges of the arteriotomy, and the sutures fastened the patch to the subjacent aorta. At 2, 6 and 12 weeks after surgery, the venous patch grafts and segments of the adjacent aortae of eight rats were removed. One-half of the specimens were analyzed by scanning electron microscopy and the other one-half by light microscopy. All patch grafts were surgically successful. Endothelial cells regenerated to cover the patch within 2 weeks of insertion. By 6 weeks after surgery, neointimal hyperplasia, consisting predominantly of smooth muscle, had developed in all patches to a thickness that was not significantly different from that of the adjacent aorta. These findings are consistent with data from other more complex experimental models of neointimal hyperplasia in the rat. We consider that this venous patch technique is a simple but effective model for the initiation of neointimal hyperplasia in the rat and may easily be used to study the experimental effects of various injurious or therapeutic agents on neointimal hyperplasia.

Animals↗
PubMed1993

Nucleotide sequence encoding the mannose-fucose-resistant hemagglutinin of Vibrio cholerae O1 and construction of a mutant.

The region of DNA encoding the mannose-fucose-resistant hemagglutinin (MFRHA) of Vibrio cholerae O1 has been localized, and the nucleotide sequence has been determined. The region contains a single open reading frame encoding 230 amino acids, corresponding to a protein of 26.9 kDa. The N terminus of this protein is atypical for a protein localized in the outer membrane. A mutant lacking MFRHA activity has been constructed by allelic exchange after inactivation via the insertion of a kanamycin resistance gene cartridge. The MFRHA-negative mutant has been assessed for virulence in the infant mouse cholera model. This mutant shows a marked defect in its ability to persist in the infant mouse gut and is incapable of competing with the wild-type organism, even when given in 25-fold excess. This defect also leads to a > 100-fold increase in the 50% lethal dose. These data suggest that the MFRHA is an important colonization factor in the infant mouse model.

Amino Acid Sequence↗
PubMed1992

Single-system ectopic ureters: a review of 12 cases.

Eight boys and 4 girls with single-system ectopic ureters were seen during a 15-year period. The abnormality was bilateral in 4 patients and the majority had major associated urological and other abnormalities. Eight ectopic ureters were reimplanted successfully into the bladder and 4 nonfunctioning kidneys were removed, as were 2 "blind" ectopic ureters. One patient died during the neonatal period and the others have been followed from 1 to 15 years. Renal function was noted to be normal in 10 patients and 1 has mild renal failure. Bladder function was normal in 8 patients. Early surgery should be undertaken in patients with single-system ectopic ureters. Stabilization of the upper urinary tract can be anticipated and satisfactory bladder function can also be expected in the majority of cases.

Child↗
PubMed1992

Psychological factors in patients with non-specific abdominal pain acutely admitted to a general surgical ward.

Non-specific abdominal pain is the commonest reason for acute admission to a general surgical ward. The present study assessed the importance of specific symptom patterns, psychological and behavioural factors in a group of acute admissions and compared patients with appendicitis with those with no specific diagnosis. Psychiatric symptoms were no more prominent than in subjects with appendicitis as measured by psychological rating scales. Patients with non-specific abdominal pain had a poor symptomatic prognosis with continuing use of medical services. NSAP is best seen as a behavioural syndrome with repeated consultation over a long period before and after the index admission for both abdominal and other non specific symptoms.

Abdomen, Acute↗
PubMed1991

Four-year retrospective survey of fire incidents in a psychiatric hospital.

This paper describes a four-year retrospective survey of fire incidents in a psychiatric hospital. The results suggest that there were sufficient similarities between a fire incident and a violent incident for the former to be included in a hospital register of violent incidents. The authors recommend that fire incidents should be studied prospectively, and that hospital fire officers should be an integral part of the multidisciplinary team auditing such incidents.

Data Collection↗
PubMed1990

Prognostic value of prolonged ventricular repolarization following myocardial infarction: the BHAT experience. The BHAT Study Group.

In the Beta Blocker Heart Attack Trial (BHAT), 3837 patients were randomized to propranolol (180-240 mg/day) or placebo 5-21 days after a documented myocardial infarction and were followed in a double blind manner for a mean period of 25 months. Twelve lead electrocardiograms were routinely obtained at the time of randomization (baseline electrocardiogram) and at 12 and 24 months of follow-up. There was a positive correlation between baseline QTc interval prolongation (but not QT prolongation) and mortality and sudden death that was independent of treatment group. The data for non-sudden death and non-fatal reinfarction exhibit similar trends. We conclude that: (1) QTc prolongation identifies a high risk subset of post myocardial infarction patients. (2) The relative benefit of propranolol is similar in patients with normal and prolonged QTc.

Death, Sudden↗