Showing papers by "Queen's University Belfast published in 1989"

Genetic differences among brown trout, Salmo trutta, stocks and their importance for the conservation and management of the species

Abstract: SUMMARY. 1. Review of published studies on genetic variation, as shown by electrophoretic studies of protein variation, in natural brown trout (Salmo trutta L.) populations from Britain and Ireland, Finland, France, Greece, Iceland, Norway, Sweden, U.S.A. and U.S.S.R., revealed abundant geographical variation in gene frequency with individual populations containing only a limited part of the gene diversity of the species. 2. Thirty-eight (54%) of the seventy gene loci examined have been found to be polymorphic in the species with an average population showing polymorphism at 16% of its loci (range 0-34.8%). 3. The brown trout is naturally subdivided into a large number of reproductively isolated and genetically distinct populations within, as well as among, drainages. 4. Two independent post-glacial colonizations, by genetically distinct races, followed by independent evolution in separate drainages over the past 13,000 years is seen as responsible for the genetic diversity of brown trout in north-western Europe. 5. Many genetically unique populations have been lost in the past 100 years and there is an urgent need to identify and conserve the remaining genetic diversity. Genetically unique populations are an irreplaceable resource for rational management in relation to angling and future aquaculture potential.

Acupuncture prophylaxis of cancer chemotherapy-induced sickness.

Abstract: In a multi-facet study we evaluated the efficacy of P6 electroacupuncture (10 Hz applied for 5 min) as an antiemetic in patients receiving a variety of cancer chemotherapy drugs. The study involved 130 (15 in an open pilot study, 10 in a randomized placebo controlled crossover study and 105 in a definitive study) patients who had a history of distressing sickness after previous treatment, and who, on the basis of a previous survey, would be expected to have a 96% chance of this with subsequent therapy. Sickness was either completely absent or reduced considerably in 97% of patients and no side effects were encountered. The limited crossover study, using a 'dummy' acupuncture (ACP) point showed that the beneficial effects were limited to the P6 point. Logistic and ethical considerations excluded the possibility of carrying out a larger placebo-controlled study. While in our hands P6 ACP was an effective antiemetic in patients having cancer chemotherapy, because of the time involved and the brevity of the action (8 h) an alternative approach to electro-ACP is required before this technique is adopted clinically.

Effect of stimulation of the p6 antiemetic point on postoperative nausea and vomiting

Abstract: The antiemetic action of stimulation of the P6 (Neiguan) acupuncture (ACP) point has been studied in women, premedicated with nalbuphine 10 mg, undergoing minor gynaecological operations under methohexitone-nitrous oxide-oxygen anaesthesia. Invasive ACP--manual or electrical at 10 Hz--applied for 5 min at the time of administration of the premedication markedly reduced the incidence of vomiting and nausea in the first 6 h after operation, compared with untreated controls. This did not occur with stimulation of a "dummy" ACP point outside the recognized ACP meridians. Non-invasive methods (stimulation via a conducting stud or by pressure) were equally as effective as invasive ACP during the early postoperative period. However, both these non-invasive approaches were less effective than invasive ACP in the 1-6 h postoperative period, although each was as effective as two standard antiemetics (cyclizine 50 mg, metoclopramide 10 mg). In view of the total absence of any side effects in more than 500 ACP procedures, the clinical applications of this finding are worthy of further study.

Post-glacial colonization of brown trout, Salmo trutta L.: Ldh-5 as a phylogeographic marker locus

Abstract: The Ldh-5 locus, which codes for the eye-specific lactate dehydrogenase in brown trout, has been shown to be polymorphic for two codominant alleles, Ldh-5 (100) and Ldh-5 (90). The Ldh-5 (100) allele is present in 11 other salmonid species and is therefore likely to be the ancestral one, whereas the unique brown trout Ldh-5 (90) allele would seem to be the result of a mutation in that lineage. The Ldh-5 (90) allele appears to have arisen in north-west Europe during or after the last glaciation, with allelic substitution taking place under the action of natural selection. The Ldh-5 (90) allele can be used as a phylogeographic marker to trace the post-glacial spread of the populations possessing it. Examination of the current distribution of the two alleles suggests that, in the formerly glaciated area of north-west Europe, there have been two post-glacial colonizations by brown trout. The first was by an ‘ancestral’ race fixed for the Ldh-5(100) allele. This was later replaced by, or introgressed with, the later-arriving ‘modern’ race characterized by the Ldh-5 (90) allele, except where physical barriers prevented colonization by this latter form. Artificial stocking has resulted in ‘genetic contamination’ of many populations of the ancestral race and there is an urgent need to conserve the remaining pristine populations, especially in view of the likely genetic propensity for longevity and ultimate large size exhibited by this race.

Fear of Crime in Residential Environments: Testing a Social Psychological Model

Abstract: We examined fear of crime in the residential environment from a theoretical and social psychological perspective by constructing a model that relates feelings of unsafety to attributions about self, the potential criminal, and the situation in which the criminal act might occur. Using data from a questionnaire field survey of 440 residents in four urban neighborhoods, the model was compared with a socio-demographic alternative (comprising such variables as gender, age, and educational level). LISREL, a relatively new method of analysis that takes measurement error into account, indicated that the model has superior explanatory power and greater in-terpretability. Multiple regression analyses confirmed these results and point to ways in which operationalization of the theoretical model might be improved.

In vivo assessment of percutaneous local anaesthetic preparations

Abstract: This study has demonstrated greater efficacy of a new percutaneous amethocaine preparation relative to Eutectic Mixture of Local Anaesthetics (EMLA). Initially, a double-blinded trial was undertaken on each preparation individually against placebo, as the recommended method of application was different for EMLA (2.5 g applied for 60 min under an occlusive dressing) and the amethocaine formulation (0.5 g applied for 30 min). Thereafter, the two preparations were compared directly, in a double-blinded study using a standardized application for both formulations. The results indicated that both preparations provided significant (chisquare; P

Antenatal screening for intrauterine growth retardation with umbilical artery Doppler ultrasonography.

Abstract: To assess the usefulness of continuous wave Doppler ultrasonography as an antenatal screening tool for the detection of intrauterine growth retardation and fetal compromise 2097 singleton pregnancies were studied. Umbilical artery velocity waveforms were obtained at 28, 34, and 38 weeks of gestation, from which the pulsatility index, A/B ratio, and resistance parameter were calculated. No abnormal features or indices of neonatal outcome were adequately predicted. The most sensitive index for being delivered of a growth retarded infant (less than 5th centile birth weight for gestation) was an A/B ratio at 34 weeks (sensitivity 40%, specificity 84%). Other measures that show poor neonatal nutritional state (ponderal index, skinfold thickness, and ratio of mid-arm circumference to head circumference) were even less well predicted. Acute and chronic hypoxia as determined by Apgar score, pH in blood from the cord artery, and packed cell volume correlated poorly with umbilical artery waveform indices, and there was no obvious difference between the indices of those who subsequently required operative or instrumental delivery for fetal distress and those requiring no intervention. There were three unexplained stillbirths in the series, in each of which the fetus had shown waveform patterns that suggested increased peripheral resistance, though the technique did not appear to be useful for predicting the time of subsequent death. Screening for small for dates babies in a three stage programme was of no value regardless of the threshold or index chosen. Obstetricians should resist the temptation to introduce screening with Doppler ultrasonography until its proper role has been determined.

Stress-induced diffusion in hydrogen permeation through Pd81Pt19 membranes

Abstract: Hydrogen permeation through a tubular membrane of Pd81Pt19 was investigated in the temperature range 257–323 K by both gaseous and electrolytic charging and discharging. In the hydrogen-free membrane the diffusion coefficient was determined by the breakthrough method and the corresponding activation energy was evaluated. Permeation through membranes with considerable hydrogen content exhibits non-local non-fickian behaviour, termed “stress-induced diffusion” (SID). A phenomenological theory is presented and direct comparison with the experimental results is given. For short permeation times the SID can be treated separately.

Immunocytochemical demonstration of neuropeptides in the nervous-system of the liver fluke, fasciola-hepatica (trematoda, digenea)

Abstract: The localization and distribution of neuropeptides in the nervous system of the liver fluke, Fasciola hepatica at different stages in the development of the adult fluke have been determined by an indirect immunofluorescence technique, using antisera to 19 vertebrate peptides and the invertebrate neuropeptide, FMRFamide. Positive immunoreactivity was obtained with antisera to pancreatic polypeptide (PP), peptide tyrosine tyrosine (PYY), substance P (SP) and FMRFamide. Cell bodies and nerve fibres immunoreactive to the 4 peptides are present in the anterior ganglia and the 3 pairs of longitudinal nerve cords and their commissures in the central nervous system. In the peripheral nervous system, immunoreactivity occurs in the nerve plexuses supplying the subtegumental musculature, the oral and ventral suckers, and the muscular lining of the male and female reproductive ducts, including the ootype, uterus, cirrus pouch and gonopore. Cells displaying immunoreactivity to PYY and FMRFamide lie amongst the Mehlis' gland cells that surround the ootype. Processes from these cells extend into the wall of the ootype. One group of PP-immunoreactive cells occurs at the junction of the vitelline and ovovitelline ducts, whilst another group is situated at the entrance to the uterus from the ootype. The results are discussed in relation to the possible roles of the peptides in the neurophysiology and egg production of the fluke.

Sensitivity of Listeria monocytogenes to irradiation on poultry meat and in phosphate‐buffered saline

Abstract: The sensitivity of four strains of Listeria monocytogenes to irradiation on poultry meat and in phosphate-buffered saline was investigated. The D10 values on poultry meat were 0.417–0.553 kGy depending on strain and plating medium used. Lower values were obtained in phosphate-buffered saline. Generally tryptone soya yeast extract and McBride agars gave a better recovery (higher D10 value) than listeria selective agar. The D10 values for L. monocytogenes were similar to those reported for Salmonella spp. irradiated under similar conditions. Therefore irradiation doses suggested to eliminate salmonellas from poultry carcasses would also be sufficient to remove L. monocytogenes.

A light microscopic and autoradiographic study of non-irradiated and irradiated ocular wounds

Abstract: Focal gamma irradiation was used to limit the intraocular extension of scar tissue which typically occurs after posterior perforating injury to the eye. Standard posterior perforating injuries were created in the right eye of forty-eight rabbits, half of which had the site of perforation focally irradiated using a Cobalt 60 ophthalmic plaque. Non-irradiated wounds healed with profuse formation of highly cellular and vascularised granulation tissue which invaded the vitreous to form contractile vitreo-retinal membranes. In irradiated eyes vitreo-retinal membrane formation was infrequent; the wounds showing only sparse granulation tissue with little or no extension into the vitreous cavity. Autoradiographic studies carried out in a second group of 40 animals showed that the episclera was the main source of the proliferating fibroblasts, and cell counts confirmed that the inflammatory and repair responses in irradiated wounds were both delayed and attenuated.

Intramembranous osteogenesis and angiogenesis in the chick embryo

Abstract: Membrane bone formation was examined in the developing chick frontal bone of Stage 32-36 embryos using alizarin red whole mounts, wax and resin histology, transmission electron microscopy and India ink injection techniques. Mineralised bone was seen at Stage 36, but was presaged by the appearance of twin mesenchymal condensations at Stage 35. The condensations appeared dorsolateral to the upper edge of the interorbital septum near its centre. The mesenchymal cells of the condensation were fusiform in shape and initially exhibited a close-packed, layered configuration which was avascular. Consequent differentiation of the central cells first into preosteoblasts and then into definitive osteoblasts, accompanied by secretion of bone matrix, coincided with blood vessel invasion of the frontal anlagen. It is suggested that these vascular changes associated with the onset of bone cell differentiation indicate that osteogenic cells may secrete an angiogenesis factor.

A comparison between propofol and thiopentone as induction agents in obstetric anaesthesia

Abstract: Two comparable series of 21 patients who had elective Caesarean section had general anaesthesia induced by thiopentone sodium 4.53 (SD 0.65) mg/kg or propofol 2.15 (SD 0.26) mg/kg. Maintenance was similar for both groups. Blood pressure was lower in the propofol group during the induction-delivery interval. Umbilical/maternal vein ratios for thiopentone and propofol were 8.5 and 7.2 respectively. Infant wellbeing as judged by Apgar score and cord blood analysis showed little difference between the two induction agents. Factors associated with uterine relaxation and bleeding were similar in the two groups.

Carbon-phosphorus bond cleavage by Gram-positive and Gram-negative soil bacteria

Abstract: Five soil bacterial isolates, originally selected for their ability to utilize the herbicide glyphosate as sole phosphorus source, were characterized with respect to their ability to use a range of other structurally-diverse phosphonates. Most showed broad substrate specificity and strains of Pseudomonas and of Bacillus megaterium were capable of degrading 14 of the other 15 phosphonates investigated. However no isolate was able to utilize isopropyl phosphanate, nor the phosphinate herbicide phosphinothricin. Growth rates on most phosphonates were significantly lower than those sustained by inorganic phosphate, and evidence was obtained for preferential utilization of the latter. In addition, the length of lag phase preceing growth on phosphonates varied widely. These characteristics are believed to reflect the diversity of routes by which such molecules enter bacterial cells and are metabolized.

Examination of Eight Cases of Multiple Sclerosis and 56 Neurological and Non-neurological Controls for Genomic Sequences of Measles Virus, Canine Distemper Virus, Simian Virus 5 and Rubella Virus

Abstract: Summary In situ hybridization studies have been carried out on brain samples from eight cases of multiple sclerosis (MS) and 56 non-neurological and neurological controls, using single-stranded 35S-labelled RNA probes prepared against genomic RNA sequences of measles virus, canine distemper virus, rubella virus and simian virus 5 Foci of hybridization were found using probes against the measles virus nucleocapsid protein (N), phosphoprotein and fusion protein gene sequences in two of the MS cases, and also in one control, a case of disseminated cytomegalovirus infection with spinal cord necrosis This result was confirmed using biotinylated probes prepared against the measles virus N genomic sequence No hybridization was found in any of the MS or control cases using any of the other viral genome-specific probes

Psychomotor Performance and Counterregulatory Responses During Mild Hypoglycemia in Healthy Volunteers

Abstract: The effect of mild hypoglycemia on psychomotor performance and counterregulatory responses was studied among 12 healthy volunteers. Each volunteer received two modified hyperinsulinemic glucose clamps. One morning, plasma glucose was held constant at euglycemic levels (4.9 mM) for 95 min, and another morning, it was lowered over 35 min and then held constant at hypoglycemic levels (3.4 mM) for 60 min. A battery of psychomotor tests and a questionnaire assessing hypoglycemic symptoms were administered before and repeated during the last 30 min of each clamp. The questionnaire and three selected psychomotor tests were also administered repetitively during the 1st h of each clamp. During the hypoglycemic studies, a rise was seen in plasma epinephrine and pancreatic polypeptide at 45 min. An increase in symptom scores was first recorded at 50 min during the hypoglycemic studies [median 4 (range 0-13) vs. 2 (5-6), P less than .05]. Performance was impaired on two psychomotor tests included in the battery. One was the trail making test on fine motor performance (-19.3 +/- 4.2 targets/min, mean +/- SE vs. 1.2 +/- 4.8 targets/min, P less than .05), and the other was the digit-symbol substitution (DSS) test on information processing and memory (18 +/- 3 vs. 29 +/- 4 symbols/min, P less than .03). Of the tests administered during the 1st h, performance was impaired on the DSS. This impairment became significant at 45 min (14 +/- 4 vs. 22 +/- 4 symbols/min, P less than .005). In conclusion, mild hypoglycemia selectively impairs psychomotor performance in healthy volunteers but not before the onset of glucose counterregulation and warning symptoms.

The frequency of gastrointestinal endocrine tumours in a well-defined population--Northern Ireland 1970-1985.

Abstract: The reported incidence of gastrointestinal endocrine tumours is variable. In Northern Ireland circumstances allowing such an assessment are favourable with a central diagnostic laboratory and register established to collect data on tumours from a well-defined population of 1.5 million people. From 1970 to 1985, 368 cases were recorded of which 85 per cent were carcinoid tumours. The annual incidence of carcinoid tumours was 1.3 per 100,000 of the population and the majority occurred in the appendix (61 per cent). No patients presented with the carcinoid syndrome. The annual incidence for other tumours was 0.12 per 100,000 for insulinomas; islet cell tumours of unknown type 0.07; Zollinger-Ellison syndrome 0.05; and multiple endocrine neoplasia (MEN) 0.05. There were two cases of VIPoma, one glucagonoma, one neurotensinoma and one tumour producing ACTH. It is possible that some tumours are more uncommon than others because of difficulty in diagnosis.