Biomedical subjects
Publications and source records attributed to J S Collins.
Of 31 patients (18 male and 13 female) followed up 13-29 years after diagnosis, recurrent or persistent duodenal ulcer had occurred in four. In 22 (71%) gastrointestinal symptoms persisted into adult life, although only abdominal pain was significantly more frequent than in 126 controls.
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A case of massive rectal bleeding resulting from the placental attachment of an abdominal pregnancy to the sigmoid colon is reported. Both mother and infant survived this rare complication which should be considered when abdominal colic and major gastrointestinal haemorrhage occur in a pregnant patient.
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The eyes of 15 species of birds from 10 families have some cones maximally sensitive at 370 nanometers in the near-ultraviolet. Spectral sensitivity was measured by recording extracellularly in opened eyecups , and a maximum in the ultraviolet was revealed by selectively adapting the retina with yellow background lights. The 370-nanometer spectral sensitivity function is attributed to receptors because its spectral position does not vary with the strength of adaptation and because it is present when the receptor potentials are isolated from the contributions of higher order retinal neurons by exposing the retina to sodium aspartate. These measurements demonstrate the basis for the ultraviolet sensitivity of birds that has been seen in behavioral experiments, and they provide further evidence that many vertebrates share with insects vision in the near-ultraviolet.
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The cone oil droplets of 19 species of birds from 11 families were examined by microspectrophotometry. Individual droplets were expanded with mineral oil, suspended in aqueous glycerol, and absorbance spectra measured between 700 and 320 nm. A classification of oil droplets is proposed, in which objective measurements of their carotenoids are related to the size, position and visual appearance of the droplets under the microscope. Some droplets contain no carotenoid and are transparent at wavelengths longer than 320 nm. Other droplets appear colorless but contain carotenoids absorbing at 385 or 402 nm. The pale droplets that have traditionally been described as greenish contain a mixture of two carotenoids. All of these types are distinct from yellow and red droplets. Red droplets contain astaxanthin esters, and yellow droplets contain a carotenoid with a spectrum similar to zeaxanthin. The 402 nm chromophore is galloxanthin, a C27 apo-carotenoid with 8 double bonds. The in vivo optical densities are 1-4 in the paler droplets, range up to about 8 in the yellow droplets, and can exceed 20 in the red droplets. All droplets that contain carotenoid can exhibit substantial absorption in the near u.v. The frequencies of the several droplet types in the retinas of different species suggests that these organelles respond readily to natural selection and may be involved in more than one function.
Iron intakes and iron status (serum ferritin and iron balance) were determined in 16 women and 13 men consuming self-selected diets over a 1-yr period. Iron balance was determined during four 7-day balance periods corresponding to the four seasons of the year. The seasonal variation in iron intake and serum ferritin and the correlation among iron intake, iron balance, and serum ferritin was examined. No seasonal variation was found in iron intake or serum ferritin. No direct correlation could be found between iron status (ferritin levels and iron balance) and iron intake. However, the men who met or exceeded their recommended dietary allowance for iron intake had ferritin levels in a range indicative of adequate iron status. None of the women met their recommended dietary allowance and their ferritin levels indicated marginal iron stores.
A patient with a right-sided descending colon, left-sided ascending colon, and transverse colon in front of the superior mesenteric artery is described. We believe that this is only the second case of "prearterial" reversed midgut rotation existing with normally situated stomach and liver. The best explanation for these relationships seems to be (a) anomalous positioning of the primitive midgut-hindgut junction right of midline; (b) ensuing midgut rotation in a reversed, or clockwise, direction.
Following fixation with glutaraldehyde, tissues or gelatin films fluoresce. This fluorescence can be enhanced more than thirtyfold by several minutes exposure to near ultraviolet light. Longer wavelengths produce a smaller effect. The enhanced fluorescence is maximally excited at 540 nm (half-band width about 45 nm), and fluorescence emission peaks at 560 nm. The rate of photoenhancement is independent of temperature in the 12--30 degrees C range. Photoenhancement is greater at alkaline than acid pH; the pH dependence involves a single acid binding group with pK = 7.3. These effects are not observed following treatment with paraformaldehyde or prior reduction with boranedimethylamine. Schiff base linkages between the bifunctional cross-linking reagent and free amino groups therefore seem to be involved. The effects of pH and wavelength on the photoenhancement of fluorescence are best accounted for by a kinetic scheme that includes both photogeneration of fluorophore from an ultraviolet-absorbing precursor, and its subsequent photodestruction by visible light.
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We have audited the first 3 yr of a new open access gastroscopy service in the Royal Victoria Hospital, Belfast to assess service demands, patient demography and diagnostic trends. Over 3 yr there were 1872 referrals (800 from fundholding general practitioners), 8.8 per cent were non attenders and 5.4 per cent cancelled appointments. Endoscopic diagnostic categories showed no significant change over the 3 yr, 39 per cent non ulcer dyspepsia, 35 per cent gastro-oesophageal reflux disease (GORD), 17 per cent peptic ulcer disease (PUD), 6 per cent GORD and PUD, 1 per cent gastric erosions and 0.8 per cent carcinoma.
Screening for Helicobacter pylori in dyspeptic patients may improve selectivity for gastroscopy. Rapid serological tests based on ELISA technique are cheap, readily available and simple to use in the clinical setting. However local evaluation is essential in order to validate these techniques. Fifty-six dyspeptic patients (aged less than 45 yr) had a rapid serological test (Helisal) performed prior to gastroscopy. At gastroscopy H. pylori status was assessed using culture and histology. The Helisal sensitivity was 80 per cent, specificity 82 per cent. Screening patients with the Helisal test would have missed 6 patients with peptic ulcer disease and 2 with oesophagitis. The Helisal test did not perform satisfactorily as a screening test in selection of patients for gastroscopy.