Biomedical subjects
Publications and source records attributed to J Porter.
The gene for phosphoryl ase b kinase, a skeletal muscle enzyme, has been located on the X chromo some of mice. The inheritance of the enzyme through two generations from original matings between one inbred strain of mice, the I, which lacks the enzyme, and another strain, the C(57,) follows the classical Mendelian pattern.
BACKGROUND: Clinical trials have shown that naltrexone 50 mg/day reduces alcohol consumption and relapse rates in alcohol dependents. AIM: To investigate the efficacy of 50mg/day dose of naltrexone in the maintenance of alcohol-dependent subjects over a 36-week treatment period. METHODS: Subjects were randomised into two equal groups, consisting of 116 male alcohol-dependent patients who met the DSM-IV criteria for alcohol dependence and were seeking treatment. The participants received naltrexone or placebo at a dose of 50 mg/day and were treated in an outpatient clinic, offering a weekly 0.5-hour individual counselling session. Days retained in treatment were measured. RESULTS: Forty-one participants (35.3%) completed the 36-week study. Completion rates by group were 44.8% for the 50 mg naltrexone group and 25.9% for the placebo group (chi2=4.56, DF=1, 2-sided significance=0.033). CONCLUSION: The results support the efficacy and safety of naltrexone for outpatient treatment of alcohol-dependent individuals in Iran.
BACKGROUND: Anaesthetists are at high risk from blood-borne pathogens. Universal Precautions (UP) include the routine use of appropriate barrier precautions and techniques to reduce the likelihood of exposure to blood, body fluids and tissues that may contain pathogens. The compliance of Irish anaesthetists with these precautions has not been studied. AIM: To study the attitudes of Irish anaesthetists to Universal Precautions. METHOD: A postal questionnaire was sent to 210 anaesthetists currently practising in Ireland. The questionnaire was based on a model used in Australia and New Zealand. RESULTS: There was a 50% response rate to the survey. Only 15% of respondents had taken a risk history from a patient in the preceding four weeks. Resheathing of needles was commonplace. The effectiveness of hepatitis B immunisation was rarely checked and only 66% of respondents believe implementation of Universal Precautions to be practical. CONCLUSION: Irish anaesthetists comply poorly with Universal Precautions.
Zucker rats are a frequently used model in obesity research. Dehydroepiandrosterone (DHEA) reduces their rate of weight gain and caloric consumption. So far, most studies have been conducted while the animals consume laboratory rodent chow, which is low in fat. In the experiments of this communication, Zucker rats were offered fat as a food choice. The goal was to determine how the consumption of fat would affect their weight gain and what effect DHEA would have on macronutrient selection. It was found that Zucker rats both male and female, lean and obese selected nearly 40% of their calories as fat when allowed to choose from nearly pure carbohydrate, protein, and fat foodstuffs. Consuming these three macronutrient diets they ate more calories and gained more weight than chow-fed controls over short periods of time. DHEA administered as an intraperitoneal injection decreased caloric intake of Zuckers. This decrement was quantitatively most important on fat intake. DHEA also prevented weight gain. It is concluded that the availability of fat food affects weight gain in Zucker rats and that DHEA modifies the selection of food such that Zucker rats eat less fat.
Recent 5 reports of severe cutaneous hypersensitivity reactions in patients infected with human immunodeficiency virus (HIV) and with tuberculosis treated with thiacetazone have prompted the World Health Organization to advise against the use of thiacetazone in patients known, or suspected, to be infected with HIV. Because the poorest countries will have great difficulty in replacing thiacetazone, the history, metabolism and possible mechanisms underlying the toxicity of this inexpensive, but problematic, drug are reviewed. Guidelines for National Tuberculosis Control Programme policies in response to thiacetazone toxicity are discussed, taking into account the differing levels of resources available to developing countries.
To determine the number of clients attending for voluntary human immunodeficiency virus (HIV) testing who are able to enter a trial of preventive therapy for tuberculosis, and the factors that determine who receives therapy, we studied 475 consecutive people attending for an HIV test at Lusaka's first voluntary HIV testing centre and the preventive therapy study clinic at the University Teaching Hospital, Lusaka, Zambia. Semi-structured interviews were conducted by counsellors and collated with recruitment data from the trial. Two hundred and twenty-five people were seropositive, of whom 201 returned to collect their results; 77 (38%) of these (16% of the total number screened) entered the trial. Reasons for not entering the trial included exclusion by trial protocol (30), including 18 who had active tuberculosis; psychological adjustment to a positive result (27); death (6); worries about confidentiality (3); the experimental nature of the trial (12); attitudes of staff in the hospital (5); and cost of transport (7). Targeting preventive therapy at those who are already choosing to be tested for HIV seems appropriate and may be cost-effective. Although visiting a hospital may deter some people, the prevalence of active tuberculosis among this group emphasized the importance of arranging adequate screening facilities.
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In a previous study, we have demonstrated that conjugates containing soluble, recombinant human CD4 (rCD4) and the deglycosylated form of ricin A chain (dgA) (rCD4-dgA) effectively kill a human T cell line infected with the human immunodeficiency virus (HIV) in vitro. In contrast, such conjugates are 100-1000-fold less toxic to uninfected cells. In order to use a rCD4-dgA conjugate effectively in vivo, it was important to demonstrate that (1) it binds to and kills HIV-infected, but not uninfected, human cells, (2) it is stable in the circulation, and (3) it has an optimal therapeutic index (toxicity to animals versus toxicity to target cells). A major factor affecting the efficacy of such conjugates in vitro and in vivo is the nature of the cross-linker between the ligand (rCD4) and the toxin (dgA). In this report, we have prepared rCD4-dgA conjugates using three different cross-linkers. Different methods of purification have been compared by determining the optimal yield, purity, and retention of biological activity (i.e., binding to gp120 and dgA chain activity). The structure of these conjugates as well as their cytotoxicity to target cells in vitro has been analyzed. Finally, we have compared their pharmacokinetics, tissue localization, and toxicity in mice.
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BACKGROUND: Rupture of the biliary system resulting in bile ascites may occur spontaneously or as a complication of inflammatory disease, biliary tract manipulation or trauma. Leakage of bile into the peritoneal cavity can cause severe chemical peritonitis, requiring rapid surgical intervention. CASE: A 64-year-old male status post total laryngectomy for squamous cell carcinoma developed abdominal pain and ascites. Diagnostic paracentesis was performed, and bile pigment was noted on cytologic examination, raising the possibility of biliary rupture. This was confirmed radiographically, and the patient underwent exploratory laparotomy, where a ruptured gallbladder was found and cholecystectomy performed. CONCLUSION: Recognition of bile pigment on cytologic examination of ascitic fluid followed by measurement of ascitic fluid bilirubin levels can alert clinicians to the presence of clinically unsuspected bile peritonitis in patients with rupture of the biliary system.
There is currently considerable debate concerning the visual impact of correcting the higher order aberrations of the eye. We describe new measurements of a large population of human eyes and compute the visual benefit of correcting higher order aberrations. We also describe the increase in contrast sensitivity when higher order aberrations are corrected with an adaptive optics system. All these results suggest that many, though not all, observers with normal vision would receive worthwhile improvements in spatial vision from customized vision correction, at least over a range of viewing distances and particularly when the pupils are large. Keratoconic patients or patients suffering from spherical aberration as a result of laser refractive surgery as it is presently performed would especially benefit. These results encourage the development of methods to correct higher order aberrations.
In this article we review the early history of the coronary artery stent in clinical cardiology, cite a clinical case and assess the potential role of stents in revascularization in the future.