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Biomedical subjects

A Thompson

Publications and source records attributed to A Thompson.

At least 325 records · Page 18Linked to original sources
PubMed1968

Cardiac autoantibodies. I. Immunodiffusion analysis of multiple responses evoked homologously and heterologously.

1. A high proportion of rabbits immunized with pooled rabbit heart homogenates in complete Freund's adjuvant responded with the production of multiple precipitating antibodies to soluble rabbit heart antigens. The most potent antisera revealed at least five distinct antigens. 2. Rabbit anti-rabbit heart antibodies reacted with similar antigens in other mammalian hearts, (human, rat, guinea pig, and bovine) with apparent "reactions of identity" by immunodiffusion. 3. Rabbits immunized with human, rat, or guinea pig heart homogenates also responded with multiple precipitating antibodies directed against rabbit cardiac antigens, although somewhat less intensively than animals immunized homologously. The specificities of these antibodies appeared to be the same as those evoked homologously. 4. The autoantibody nature of the homologously and heterologously induced responses was unequivocally demonstrated in several instances by reactions between the sera from immunized rabbits and their own hearts. 5. Many of the autoantibodies appeared to be directed against antigens restricted to the heart, judging by comparative immunodiffusion tests with other rabbit tissue extracts. This was convincingly confirmed by multiple absorption of potent antisera with several rabbit tissues. The cardiac-restricted antigens were also present in heart extracts of other mammalian species. In those instances where some of the cardiac-evoked autoantibodies reacted with other rabbit tissues, the tissue cross-reactions were quite variable. 6. Rabbits immunized with guinea pig heart homogenate suffered a high early mortality of undetermined cause, compared to animals immunized with rabbit, human, or rat hearts. 7. A small proportion of the anti-heart sera revealed immunodiffusion reactions with Group A streptococcal products, derived from organisms grown in antigen-free media. In these few instances, the reactions appeared unrelated to cardiac autoantibody responses.

Animals↗
PubMed1968

Whither medicine?

Explore the source record for details and available documents.

Medical Staff, Hospital↗
PubMedDate not supplied

Laparoscopic cholecystectomy in transplant patients.

Acute cholecystitis is a serious condition in transplant patients and elective cholecystectomy is generally recommended when gallstones are found. We reviewed the results of laparoscopic cholecystectomy (LC) in 10 immunosuppressed transplant patients (6 heart, 4 kidney) and compared them to the results of open cholecystectomy performed in 26 transplant patients (14 heart, 11 kidney, 1 kidney/pancreas). The LC group had a 20% incidence of minor complication with no major complications and no deaths. The open-cholecystectomy group experienced 19% minor complications, 23% major complications, and 15% deaths. The average postoperative length of stay for the LC patients was 4.6 days (2 days for the 5 straightforward cases) as compared to 9.1 days after open cholecystectomy (4 days for the 13 straightforward open cases). Oral immunosuppression was stopped prior to operation but could be restarted within 29 hours after operation in the LC patients and 68 h in the open cases. The findings at LC were helpful in assessing whether acute cholecystitis and/or choledocholithiasis was the source of fever, liver-function abnormalities, or pancreatitis in these immunosuppressed transplant patients. We conclude that LC can be performed safely in transplant patients, but that in 10-20% of patients, the operation will be converted to an open procedure. The advantages of LC in these patients are a shorter hospitalization and less delay to resumption of preoperative oral immunotherapy than after open cholecystectomy.

Adult↗
PubMedDate not supplied

Supplemental oxygen does not synergize with intracoronary radiation for the prevention of restenosis in porcine coronary arteries.

PURPOSE: Recurrence of obstructive coronary arterial lesions (restenosis) after angioplasty remains a significant clinical problem. Ionizing radiation, at doses >10 Gy administered locally to the angioplasty site, has been shown to inhibit restenosis in porcine coronary arteries, but lower doses are ineffective. Methods that will allow delivery of lower doses of radiation while retaining the antirestenotic efficacy observed at the higher doses are desirable. Hypoxic cells are known to be radioresistant; accordingly, we hypothesized that increasing blood oxygenation through the use of the TherOx Aqueous Oxygen system would lower the doses of endovascular radiation required for the prevention of restenosis. MATERIALS AND METHODS: Five swine were studied as follows: balloon injury + oxygen alone was performed in two swine. Each swine had a balloon overstretch injury in two arteries, left anterior descending (LAD) and either right coronary artery (RCA) or left circumflex (LCX) artery (three arteries total). Balloon injury + oxygen followed by intracoronary irradiation was performed in a further three swine (six arteries). Controls consisted of arteries treated with 0, 5, or 15 Gy of 192Ir alone. RESULTS: Arteries treated with the TherOx Aqueous Oxygen system alone were indistinguishable from arteries treated without oxygenation except for a larger adventitial area (5.29 +/- 0.20 vs. 2.77 +/- 0.28 mm2; p < 0.05). Arteries treated with the TherOx Aqueous Oxygen system along with 5 Gy of 192Ir exhibited a greater injury-corrected intimal area than arteries treated with radiation alone (0.76 +/- 0.18 vs. 0.33 +/- 0.08 mm2; p < 0.05). Neither thrombosis rate nor thrombus area was significantly different in arteries receiving the TherOx Aqueous Oxygen as compared with controls. CONCLUSIONS: The TherOx Aqueous Oxygen system is safe in the context of balloon overstretch injury, but decreases the antirestenotic efficacy of 5 Gy of 192Ir. These findings suggest that hypoxia does not seem to be a major contributor to the dose of radiation required for suppression of neointima, at least when using noncentered gamma radiation delivery systems.

Animals↗
PubMedDate not supplied

Intracellular Ca2+ and cytotoxicity.

Following injury or activation in some immune cell lines, elevation of intracellular Ca2+ concentration (Cai2+) is an early and major event that precedes cell death. Agents shown to elevate Cai2+ and to result subsequently in the death of some cells include human immunodeficiency virus (HIV) (in T4+ cells), 25-hydroxy cholesterol, tumor necrosis factor (TNF), cyclosporine, dexamethasone, alpha-interferon, and Ca2+ ionophores. The effects of these agents, both on Cai2+ and on cytotoxicity, are additive. This type of Ca2+-related cytotoxicity may be associated with either accelerated synthesis of triglycerides (TNF), accelerated synthesis of cholesterol ester (25-hydroxy cholesterol), or cholesterol (HIV) and terminally with declining synthesis of structural phospholipid. Agents that can lower Cai2+ (e.g., phorbol esters, diglycerides, lipoproteins [LDL], oleic acid, or serum) under appropriate conditions ameliorate the Ca2+-induced cytotoxicity. Metabolism of other divalent metals, i.e., Zn2+ and Cd2+, also become altered with cell injury, e.g., glucocorticoids elevate Cai2+, but block uptake of Zn2+. These observations support the idea that chronic elevation of Cai2+ by many chemically unrelated agents leads to cell death by creating imbalance both in cell biosynthetic mechanisms--especially in those controlling lipid metabolism--as well as creating imbalances in metabolism of other trace metals, especially Zn2+.

Animals↗
PubMedDate not supplied

Setting up waiting-time targets to satisfy patients: an application of mathematical programming.

An out-patient-waiting-time standard has been set up by the government in the Patient's Charter and the standard is supposed to be effective nationwide indiscriminately. This standard is static and does not take into account local variations in patient expectations, patient unpunctualities in keeping their appointments, changing demand, and resource (or budget) constraints. Therefore, it is not surprising that many acute hospitals or Trusts (including the best-known teaching hospitals) have failed to achieve a satisfactory performance against this standard. In this paper, we argue that, while regarding this standard as the government's expectation, local out-patient-waiting-time targets could be set up more comprehensively each year on the basis of prevailing patient expectations, so that the most cost-effective (or optimal) quality is achieved instead of the ideal (or best) quality. We have also developed a mathematical-programming model which can be used to help determine the out-patient waiting-time targets in a systematic way, once the expected degrees of patient satisfaction are specified. A numerical example is provided to illustrate how the model works.

Ambulatory Care↗
PubMedDate not supplied

Transforming negative work cultures: a practical strategy.

At a time of unprecedented turbulence and challenge for healthcare organizations, maintaining healthy work environments is of paramount importance. Such environments support the day-to-day work of an organization and link its mission to customer service strategies and goals. We describe an unhealthy work culture and outline a practical approach that healthcare managers and clinical leaders can use to facilitate and sustain cultural transformation. The model is built on the core principles of ownership and investment in service outcomes as well as the life of the organization.

Attitude of Health Personnel↗
PubMedDate not supplied

Effect of nizatidine and ranitidine on 24 hour intragastric pH, pepsin, prostaglandin E2 and serum gastrin concentrations in healthy volunteers.

In order to achieve possible greater therapeutic efficacy, ranitidine 300 mg bid (R2) may be given rather than 300 mg qhs (R1), or nizatidine 300 mg bid (N2) may be given rather than 300 mg qhs (N1). A randomized placebo-controlled crossover study was performed in six healthy volunteers (four males, two females) who ranged in age from 23 to 43 years, comparing R1, R2, N1 and N2 versus placebo (P), measuring 24 h intragastric pH by the aspiration technique, gastric juice pepsin and prostaglandin E2 (PGE2) concentrations, as well as serum gastrin concentrations. In all treatment groups, 24-h intragastric pH was higher than with P; the 24 h and daytime (0800-2200 h) pH was higher with N2 than with N1, but not with R2 versus R1. The percentage pH > or = 3 was greater with N2 than with N1 during the daytime. Night-time (2200-0800 h) and 24 h pepsin concentrations were higher in R2 than in R1, were similar in N1 and N2, and were lower in these treatment groups than in P. The gastric juice PGE2 concentration at night-time, but not at daytime, was increased in the four treatment groups compared with P. Despite the higher pH values at night-time in the treatment groups, the night-time concentrations of serum gastrin were unchanged, and yet during the daytime the higher values of pH were associated with increased gastrin concentrations when R2 or N2 were given, but not with R1 and N1. There was a negative correlation between intragastric juice pH and pepsin concentration during the daytime, and a positive correlation between pH and PGE2 concentration during the night-time. The slopes and y-axis intercepts between pH and pepsin or PGE2 concentrations differed between the placebo and the treatment groups, suggesting that these H2-receptor antagonists may have an effect on lowering pepsin and raising PGE2 concentrations in addition to their effects on pH. As the percentage of time over the 24 h period and night-time periods when the pH was greater than 3 was not different between ranitidine and nizatidine, the two regimens will likely have similar clinical efficacy.

Adult↗
PubMedDate not supplied

Effects of changes in dietary intake of sodium and potassium and of metabolic acidosis on 11beta-hydroxysteroid dehydrogenase activities in rat kidney.

BACKGROUND/AIM: Glucocorticoid activity is modulated by NADP(+)- and NAD(+)-dependent isoforms of the enzyme 11beta-hydroxysteroid dehydrogenase (11betaHSD) which convert glucocorticoids to their inactive metabolites. The NAD(+)-dependent isoform, 11betaHSD2, is present in the distal nephron where it confers aldosterone specificity on mineralocorticoid receptors. The objective of this study was to establish whether renal 11betaHSD activities are affected by changes in sodium and potassium balance and by metabolic acidosis. METHODS: Renal 11betaHSD activities were measured ex vivo from rats fed normal and high- and low-potassium diets and a low-sodium diet or given 1.5% NH(4)Cl to drink. RESULTS: Rats maintained on high-potassium and low-sodium diets exhibited 59% (p < 0.01) and 28% (p < 0.05) decreases, respectively, in NAD(+)-dependent renal 11betaHSD activity (relative to rats fed control diet) with no changes in NADP(+)-dependent cortisol oxidation. Short-term (3 day) and longer-term (10 day) metabolic acidosis also decreased NAD(+)-dependent 11betaHSD activity by 50 and 52%, respectively, without affecting NADP(+)-dependent cortisol oxidation. The low-potassium diet had no detectable effect on renal 11betaHSD activities. CONCLUSION: These results suggest that adaptations to a high-potassium or a low-sodium diet and to metabolic acidosis involve decreases in renal 11betaHSD2 activity, enhancing the access of glucocorticoids to renal corticosteroid receptors.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMedDate not supplied

The fate and removal of triclosan during wastewater treatment.

This work examines the variation in removal efficiency of triclosan in wastewater treatment works in the United Kingdom between November 2003 and April 2004. Concentrations of triclosan were measured at set points within three different types of wastewater treatment works: rotating biological contactors, trickling filters, and activated sludge. Overall removal of triclosan through these plants ranged from 58 to 96% (rotating biological contactors), 86 to 97% (trickling filter), and 95 to 98% (activated sludge).

Anti-Infective Agents, Local↗
PubMedDate not supplied

Setting standards in diabetes education.

The project described in this article was undertaken to develop and improve the levels of nursing knowledge on diabetes mellitus and subsequently improve the quality of patient education on diabetes. A written standard on health education was devised and an educational programme for nurses was implemented to prepare nurses to meet the requirements of the standard. The project is ongoing, and initial results suggest that while there have been problems, nurses appear to be more confident in assuming their roles as patient educators.

Curriculum↗
PubMedDate not supplied

Research into expressions of attitudes about drugs--what use is it?

The authors draw attention to an assumption often implicit in presentation and utilisation of attitude data, that attitudes are the cause of behaviour. They then present attitude data collected from English schoolchildren with various levels of familiarity with drugs--these data could be interpreted in many ways and are compatible with the hypothesis that pupils' social experiences and behaviour may precede and influence their attitudes. It is suggested that the concept of the "transitional process" between socially available roles may be useful to researchers, evaluators and programme planners.

Adolescent↗