Biomedical subjects
S Dover
Publications and source records attributed to S Dover.
NICE guidelines?
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Immediate CT pneumocolon for failed colonoscopy; comparison with routine pneumocolon.
AIM: To assess the role and reliability of 2D CT pneumocolon in the diagnosis of colonic malignancy, and compare feasibility of referral sources. MATERIALS AND METHODS: A prospective study of 50 patients with suspected large bowel malignancy. Patients underwent bowel cleansing, rectal air insufflation and contrast enhanced CT with 5 mm collimation, 3 mm reconstruction and a pitch of 1.4. Subsequent correlation was with pathology (16), colonoscopy (13), barium enema (5), ERCP (1) and clinical follow-up alone (8). RESULTS: Diagnostic images were obtained in 43/50 patients (86% feasibility). Follow-up was obtained in 35/43 patients (one patient died of an unrelated cause, and seven patients were deemed unfit for further investigation). Seventeen colonic carcinomas were diagnosed (three false-positives: one ischaemic colitis, one diverticular stricture and one faecal mass), one diverticular stricture, one fistula, one pancreatic carcinoma and one ovarian malignancy. The remaining 14 were negative. Overall sensitivity was 100% (for lesions >1.5 cm) with a specificity of 94% for structural abnormalities, but only 82% for the correct identification of malignancy. CONCLUSION: Computed tomography (CT) pneumocolon is a reliable alternative to barium enema where colonoscopy is incomplete, with the advantage of extraluminal screening, and examination of the proximal bowel. In the frail elderly or young unfit patient, it is a valuable additional diagnostic tool.
A potential model for early stages of chromosomal evolution via concentric Robertsonian fans: a large area of polymorphism in southern short-tailed shrews (Blarina carolinensis).
Western Tennessee contains unusually highly polymorphic populations of southern short-tailed shrews (Blarina carolinensis). We previously documented eight Robertsonian translocations (ROBs) accounting for a variation in diploid number from 46 in most of this species' range to 34-40 in western Tennessee. We have now expanded our study to include data from adjacent areas in Tennessee and Mississippi, 10 localities in all. The new data show a variation in diploid number ranging from 31 to 41, four new ROBs (for a total of 12), and the novel finding of monobrachial translocations in this group. All animals collected from this large area (extending over 12, 000 km(2)) had some level of ROBs, and none represented the 2n = 46 form seen in other parts of the range of this species. Because other species of shrews (genus Sorex) are not affected in the same area, the factors and/or selective forces causing this extensive polymorphism in B. carolinensis must be unique to this species and to this geographic area. Some ROBs were found throughout this large area of over 12,000 km(2). Other translocations (including those with monobrachial homology) were located in one or two localities in this large area, and still other translocations were intermediate in their distribution. There was a concentric pattern to the evolution and presumed spreading of the ROBs. This allowed us to expand the concept of a Robertsonian "fan," introduced by Matthey (1970), to that of concentric evolution of multiple fusion fans: ROBs likely arose independently, separated temporally and geographically, and radiated into surrounding populations to create this complex zone of polymorphism. This is an active process in its infancy, and it is not as mature as that seen in European studies of Mus and Sorex.
The future of oral and maxillofacial surgery in the UK: the trainees' perspective.
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Haem precursor effects on [3H]-PK 11195 binding to platelets.
The haem precursors delta-aminolaevulinic acid (ALA) and porphobilinogen (PBG), over-produced in acute intermittent porphyria (AIP), may mediate porphyric neuropathy. Porphyrins bind to peripheral benzodiazepine receptors, putative mitochondrial porphyrin translocation sites. In AIP, ALA and PBG may interfere with porphyrin transport causing a deficit in essential haemoproteins. The effects of ALA, PBG and protoporphyrin 1X on the binding of [3H]-PK 11195 to platelets were examined. Ligand binding was also examined in platelets from porphyric patients. The haem precursor protoporphyrin 1X (10 microM) caused an increase in Kd values (p < 0.05) whereas Bmax values remained unaltered. Neither ALA (10 microM) nor PBG (10 microM) altered ligand binding. Patient platelets showed no change in ligand binding values. ALA and PBG are unlikely to compete with porphyrins for peripheral benzodiazepine sites.
Low prevalence of Helicobacter pylori in inflammatory bowel disease: association with sulphasalazine.
The prevalence of IgG antibodies to Helicobacter pylori was examined in 110 patients with inflammatory bowel disease (IBD) (63 ulcerative colitis, 47 Crohn's disease) and compared with 100 age and sex matched control patients. The overall prevalence of H pylori seropositivity in the IBD patients was 22%, which was significantly less than that of 52% in the controls (p < 0.002). There was no difference in prevalence between ulcerative colitis and Crohn's patients. The low seropositivity in the IBD patients resulted from a very low prevalence of 10% in those currently receiving sulphasalazine (n = 40) and similarly low prevalence of 7% in those previously receiving sulphasalazine (n = 30). In those receiving olsalazine or mesalazine and who had never had sulphasalazine, the prevalence of seropositivity was 45%. Further studies using 14C urea breath test and microscopy of antral biopsy specimens confirmed that the negative serology in patients receiving sulphasalazine resulted from absence of the infection rather than absence of humoral immune response to it. In six control patients with H pylori infection, a two week course of sulphasalazine (500 mg four times daily) only caused slight suppression of the 14C urea breath test. In vitro studies failed to show any direct antibacterial effect of sulphasalazine on H pylori. These findings indicate that longterm treatment with sulphasalazine leads to eradication of H pylori infection and that this does not result from a direct antibacterial effect. It may be caused by the drug treating the gastritis and thereby depriving the bacterium of essential nutrients exuded by the inflamed mucosa.
Normal serum alpha-fetoprotein in acute hepatic porphyria.
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Granulomatous enterocolitis associated with therapeutic irradiation.
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Glasgow patients' attitude to doctors' dress and appearance.
Three hundred out patients were surveyed by questionnaire to determine their views of doctors' dress and appearance. The majority felt that this was important. Most patients did not mind a male doctor with an earring, a women in trousers or a man without a tie. A majority preferred their doctors to wear a white coat, be free of political badges and for men to have conventional length hair. Older patients are stricter than young patients. Most strict patients would accept more relaxed standards at night and during the weekend.
Distress caused by urethral catheters.
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Advances in the use of opioids for domiciliary terminal care.
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Therapeutic progress--review XXIII. Morphine analgesia in terminal care.
Pain as a problem in terminal care is considered in this review with particular emphasis on the use of opiates. The choice of routes of administration is discussed in detail and the role of combination of opiates with anti-emetics and steroids is considered.
Associations of sire, breed, birth weight, and sex in pigs with congenital splayleg.
Data on 4,411 male and 4,148 female progeny from the University of Missouri-Columbia swine research herd were analyzed to evaluate the associations of sire, breed, weight at birth, and sex of the pigs with the development of congenital splayleg. Statistically significant differences in frequency of splayleg were found among sires and among breeds indicating a genetic influence. Differences in frequencies among male vs female progeny also were found to be statistically significant. The overall frequency among male progeny was 1.74 times that observed among female progeny. Comparison of birth weights of splayleg vs normal pigs showed birth weights to be statistically significantly smaller among affected pigs.
Genetic analysis of the gamma-aminobutyrate utilization pathway in Escherichia coli K-12.
The control mutation that results in a concomitant severalfold increase in the activities of gamma-aminobutyrate-alpha-ketoglutarate transaminase (GSST, EC 2.6.1.19) and succinic semialdehyde dehydrogenase (SSDH, EC 1.2.1.16), leading to the acquisition of the ability to utilize gamma-aminobutyrate (GABA) as the sole source of nitrogen by Escherichia coli K-12 mutants, was mapped by mating and transduction with P1kc. The locus affected, gabC, is approximately 48% co-transduced with the thyA gene, located at min 55 of the E. coli K-12 chromosome. The structural gene of the first enzyme in the GABA pathway, GSST, was mapped by interrupted mating, using one of the GSST-less mutants, DB742, isolated in this work. The mutated locus, gabT, is situated at about min 73 of the E. coli chromosome, close to the gltC gene. Genetic evidence concerning the sensitivity of the enzymes of the GABA pathway to catabolite repression under different physiological conditions suggests that the two structural genes of the GABA regulon do not constitute one operon.
Novel type of catabolite repression in the pathway of gamma-aminobutyrate breakdown in Escherichia coli K-12.
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Sodium and potassium requirements for active transport of glutamate by Escherichia coli K-12.
Active transport of glutamate by Escherichia coli K-12 requires both Na(+) and K(+) ions. Increasing the concentration of Na(+) in the medium results in a decrease in the K(m) of the uptake system for glutamate; the capacity is not affected. Glutamate uptake by untreated cells is not stimulated by K(+). K(+)-depleted cells show a greatly reduced capacity for glutamate uptake. Preincubation of such cells in the presence of K(+) fully restores their capacity for glutamate uptake when Na(+) ions are also present in the uptake medium. Addition of either K(+) or Na(+) alone restores glutamate uptake to only about 20% of its maximum capacity in the presence of both cations. Changes in K(+) concentration affect the capacity for glutamate uptake but have no effect on the K(m) of the glutamate transport system. Ouabain does not inhibit the (Na(+)-K(+))-stimulated glutamate uptake by intact cells or spheroplasts of E. coli K-12.
Utilization of -aminobutyric acid as the sole carbon and nitrogen source by Escherichia coli K-12 mutants.
Wild-type strains of Escherichia coli K-12 cannot grow in media with gamma-aminobutyrate (GABA) as the sole source of carbon or nitrogen. Mutants were isolated which could utilize GABA as the sole source of nitrogen. These mutants were found to have six- to ninefold higher activities of gamma-aminobutyrate-alpha-ketoglutarate transaminase (EC 2.6.1.19) and succinate semialdehyde dehydrogenase (EC 1.2.1.16) than those of the wild-type parent strains. Secondary mutants derived from these GABA-nitrogen-utilizing strains were able to grow on GABA as the sole source of carbon and nitrogen. They also grew faster on a variety of other carbon and nitrogen sources, and their growth was more strongly inhibited by different metabolic inhibitors than was that of the parent strains. The nature of the two mutations and the possible genes involved are discussed. A scheme of the pathway for GABA breakdown in E. coli K-12 is presented.