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Biomedical subjects

B Evans

Publications and source records attributed to B Evans.

At least 19 recordsLinked to original sources
PubMed1995

Laparoscopic surgery for inflammatory bowel disease.

In the setting of inflammatory bowel disease (IBD), laparoscopic approaches have been avoided because of the often fragile intestinal tissue, thickened mesentery, malnutrition, immunosuppression, and the presence of dense adhesions. In this article, we report 10 successfully managed laparoscopic cases in IBD patients (five with ulcerative colitis, five with Crohn's Disease). Patients with ulcerative colitis underwent total abdominal colectomies, mucosal proctectomies, J-pouch construction, and diverting ileostomies. Procedures in patients with Crohn's disease included ileocecectomy (3), sigmoid colectomy with takedown of a transverse colonic fistula (1), and stricturoplasty (1). One of the 10 cases was converted to an open technique for technical reasons. Six of the 10 patients were on high dose corticosteroids for disease control. Hospital stay ranged from 6-13 days, with a median of 7 days. The morbidity rate was 20 per cent, and included one case of mild postoperative pancreatitis in a Crohn's disease patient and one delayed peri-ileostomy fistula in an ulcerative colitis patient. There was no mortality. Based on these results, we conclude that laparoscopic intestinal surgery is both feasible and safe in selected patients with inflammatory bowel disease. Use of laparoscopic techniques in these patients may reduce hospital stay, lessen adhesion formation, and improve cosmetic results in this generally young group of patients.

Adolescent↗
PubMed1995

Cold urticaria, raised IgE and HIV infection.

We present a patient with cold urticaria as an unusual and late cutaneous manifestation of acquired immunodeficiency syndrome. The severe CD4 cell depletion and markedly elevated serum IgE levels in our patient provide some insights into certain aspects of immune regulatory mechanisms.

Adult↗
PubMed1993

Non-radiological technique for three-dimensional imaging of endoscopes.

A novel system is described which images in three dimensions, the total configuration of a colonoscope without the use of conventional radiological techniques. A low intensity magnetic field is used in conjunction with a miniature inductive sensor. The system intrinsically safe and it is potentially inexpensive and capable of being used in a normal hospital environment. Clinical trials are described in which the system is validated in terms of its suitability for the application. Magnetic and conventional X-ray images obtained ex vivo with the endoscope held in various configurations and comparisons in the patients confirm the practical applicability of the new system.

Colonoscopes↗
PubMed1992

Bending-incompetent variants of Flp recombinase mediate strand transfer in half-site recombinations: role of DNA bending in recombination.

One key feature of the interaction of Flp recombinase with its target site (FRT) is the large bend introduced in the substrate as a result of protein binding. The extent of bending was found to depend on the phasing and spacing of the Flp monomers occupying the two Flp-binding elements (FBE) bordering the strand-exchange region (spacer) of the substrate. The relative mobilities of the Flp complexes formed by the two permuted substrate fragments, containing the FRT site near the end or in the middle, corresponded to a DNA bend of approx. 140 degrees when each of the two FBEs flanking the spacer was occupied by a protein monomer. The estimated bend angle was the same when the reference DNA fragment with the FRT site at the end was substituted by one with the site in the middle, but containing a 4-bp insertion within the spacer. We used a combination of wild-type Flp and Flp variants that were competent or incompetent in DNA bending, together with full, or half FRT sites, to ask whether bending is a conformational requirement for catalysis, namely cleavage and exchange of strands. We obtained the following results: in full-site (FRT) vs. full-site recombinations or in full-site vs. half-site (half FRT) recombinations, there was a large difference in the reactivity between Flp and a bending-incompetent Flp variant. This difference virtually disappeared when reactions were done with half-FRT sites. We conclude that bending is not a prerequisite for catalysis, but represents the manner in which the substrate accommodates the Flp protomer-protomer interactions that are pertinent to catalysis.

Base Sequence↗
PubMed1992

A population-wide profile of prescription drug use in Saskatchewan, 1989.

OBJECTIVE: To measure the prevalence of prescription drug use in Saskatchewan in 1989. DESIGN: Retrospective study. PARTICIPANTS: A total of 961,203 Saskatchewan residents (including those who died or were born during the study year) who were eligible for coverage under the Saskatchewan Prescription Drug Plan. The study population represented 94% of the province's total population; those excluded were mostly status Indians (for whom a federal plan is available). MAIN RESULTS: At least one prescription was received by 66.0% of the study population in 1989. The mean number of prescriptions per patient was 8.2, and the mean cost of drug material per prescription was $13.95. Females received substantially more prescriptions than males; the difference was particularly notable for cardiovascular agents, antidepressants and benzodiazepines. In the senior population 80.8% received at least one prescription; the mean number of prescriptions per patient was 18.4. The most commonly dispensed drug for the entire study population was amoxicillin (290 prescriptions per 1000 people); triazolam was the most frequently dispensed central nervous system drug (74 prescriptions per 1000 people). Regional variation in overall drug use was remarkably small, although it increased at the drug-class level, especially for tranquillizers. The use of cardiovascular drugs was 27% to 32% higher (depending on how use was measured) per Regina resident than per Saskatoon resident. Benzodiazepines were commonly used on a long-term basis, despite recommendations to the contrary. CONCLUSIONS: The results quantify the prevalence of prescription drug use, underscore the importance of careful management of drug therapy by physicians and pharmacists (especially for seniors), illustrate substantial variation in drug therapy strategies and raise questions about utilization of benzodiazepines and cardiovascular drugs.

Age Factors↗
PubMed1992

The effect of cyclosporin A on cationized bovine serum albumin-induced nephropathy in NZW rabbits.

The effect of cyclosporin A (CyA) was studied on the morphology and protein excretion of a rabbit chronic serum sickness nephritis using cationized bovine serum albumin (cBSA). One group of rabbits was given intravenous (i.v.) immunizing doses of cBSA and Escherichia coli endotoxin. One week later, these animals began a 6-week i.v. injection schedule of cBSA only. A second group followed the same injection protocol, but was given intramuscular (i.m.) CyA for 3 days prior to the immunizing dose of cBSA/endotoxin and throughout the subsequent cBSA schedule. A third group was given i.m. CyA only. Regular blood samples for CyA levels were taken from animals given the drug. Two 24-h urine samples were obtained from all animals in the study. Analysis of the blood samples showed that immunosuppressive levels of CyA were achieved after two i.m. doses of CyA. These levels were maintained during the course of the schedule. Morphologically, all rabbits completing the cBSA only injection schedule showed evidence of an immune-mediated glomerulopathy with variably severe membranous and endocapillary proliferative change. Less than half the rabbits in the cBSA/CyA group showed any evidence of membranous change. The glomeruli of animals given CyA only were normal. No morphological evidence of CyA toxicity was seen in any animal given the drug. The proteinuria profiles, however, suggested that as well as reducing protein excretion in rabbits given cBSA, CyA may interact with the immunizing dose of cBSA to produce an early, reversible, nephrotoxic effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Auditing AIDS reporting. Experience from a central London district 1982-1991.

OBJECTIVE: To evaluate completeness of reporting of cases of AIDS to the Communicable Disease Surveillance Centre (CDSC) between 1982-1991. SETTING: Southside of the Bloomsbury and Islington District Health Authority. DESIGN: Reconciliation exercise with CDSC of cases reported with those known to have received treatment in the district from 1982 to March 1990. Case note review of unreported cases and follow-up at March 1991. MAIN OUTCOME MEASURES: Delayed and non-reporting of cases. RESULTS: Cumulatively 13% (46/351) of patients whose initial AIDS illness was diagnosed in the District remained unreported by March 1991. Non-reporting increased from 9% (2/23) of cases diagnosed prior to 1985 to 28% (26/92) of cases diagnosed between 1989 and 1990. After September 1987 the proportion of patients with a diagnosis of Pneumocystis carinii pneumonia or Kaposi's sarcoma was significantly higher in the reported group than in the non-reported group: 78% (124/158) v 51% (24/49) p < 0.001. Nine of 19 (47%) cases of AIDS transferring their care into the district had not been reported by their previous District Health Authority. CONCLUSIONS: Within the district non-reporting of cases of AIDS has risen over time as the numbers of patients treated has increased. The physician must be aware of the full AIDS case definition for surveillance purposes and the implications of non-reporting for the allocation of special "ring-fenced" resources for AIDS care. Adequate investment in information and reporting systems would seem essential.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Glomerular epithelial cell endocytosis in puromycin-induced glomerulopathy.

Glomerulopathy and nephrotic syndrome were induced in rats by intravenous puromycin aminonucleoside. Ten days after the injection of puromycin, the animals have developed heavy proteinuria. During this phase, glomerular epithelial cell endocytosis was studied by injecting a conjugate of horseradish peroxidase and poly-L-lysine. This conjugate has been shown to be endocytosed by glomerular epithelial cells. The rats were serially sacrificed from 1 min to 24 h after this injection. Peroxidase was localised cytochemically and observed at light and electron microscopy. The early events of endocytosis in glomerulopathy (namely the binding to the plasma membrane, the membrane invagination and the formation of the early vesicles) were qualitatively similar to those in the normal. The later events (the fusion of the vesicles and their movement within the cells) were inhibited. The results show that puromycin aminonucleoside damages epithelial cell endocytotic activity and affects the later processing of the conjugate within the cells.

Animals↗
PubMed1992

Heterozygote ornithine transcarbamylase deficiency presenting as symptomatic hyperammonemia during initiation of valproate therapy.

Ornithine transcarbamylase is a mitochondrial urea cycle enzyme. Women with heterozygous ornithine transcarbamylase deficiency may have no symptoms or have episodic, symptomatic hyperammonemia, which can be fatal. We report a previously undiagnosed heterozygote ornithine transcarbamylase-deficient patient who had symptomatic hyperammonemia during initiation of valproate therapy. This is the second such patient reported. Symptomatic hyperammonemia during valproate therapy may indicate ornithine transcarbamylase deficiency. Since valproate inhibits ureagenesis and can be toxic to mitochondria, it should be used extremely cautiously, or not at all, in ornithine transcarbamylase-deficient patients.

Adult↗
PubMed1991

Is risk of Kaposi's sarcoma in AIDS patients in Britain increased if sexual partners came from United States or Africa?

OBJECTIVE: To determine whether the risk of Kaposi's sarcoma in patients with AIDS is increased by sexual contact with groups from abroad with a high incidence of Kaposi's sarcoma. DESIGN: Analysis of risk of Kaposi's sarcoma in patients with AIDS, according to country of origin of their sexual partners. SETTING: United Kingdom. PATIENTS: 2830 patients with AIDS reported to the Communicable Disease Surveillance Centre and the Communicable Disease (Scotland) Unit up to March 1990, of whom 566 had Kaposi's sarcoma. MAIN OUTCOME MEASURES: Percentage of patients with AIDS who had Kaposi's sarcoma. RESULTS: 537 of 2291 homosexual or bisexual men (23%) with AIDS had Kaposi's sarcoma; 10% (14/135) of the men and women who acquired HIV by heterosexual contact had Kaposi's sarcoma. None of the 316 subjects who acquired HIV through non-sexual routes had Kaposi's sarcoma. Kaposi's sarcoma was more common among homosexual men whose likely source of infection included the United States (171/551, 31%) or Africa (9/34, 26%) than among those infected in the United Kingdom (119/625, 19%) (p less than 0.05). CONCLUSION: The data suggest that Kaposi's sarcoma is caused by a sexually transmissible agent which was introduced into the British homosexual population mainly from the United States [corrected].

Acquired Immunodeficiency Syndrome↗
PubMed1991

Determinants of somatization in primary care.

This study explores possible determinants of somatization in primary care. Hypotheses were tested on samples of 'somatizers', 'psychologizers' and controls recruited by epidemiological procedures. Although 'somatizers' were found to be similar to 'psychologizers' in many respects, they were (i) less depressed; (ii) reported lower levels of social dissatisfaction, social stress and less dependence on their relatives; (iii) more likely to have an unsympathetic attitude towards mental illness and less likely to consult a doctor about psychological symptoms, and (iv) more likely to have received medical in-patient care as an adult before they had consulted their doctor with their current illness. These findings are discussed in the context of previous research.

Adaptation, Psychological↗