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Biomedical subjects

A J Carmichael

Publications and source records attributed to A J Carmichael.

At least 19 recordsLinked to original sources

Candidaemia in a large teaching hospital: a clinical audit.

BACKGROUND: Candidaemias are associated with significant morbidity and mortality. The British Society of Medical Mycology and Infectious Diseases Society of America recently published audit standards, to address the changing epidemiology of candidaemia and to improve outcomes. AIM: To investigate the local epidemiology of candidaemia and the standard of care in a large teaching hospital. DESIGN: Retrospective audit. METHODS: Data were obtained for all candidaemia episodes over the 4-year period ending July 2004, from the medical and nursing notes, laboratory computer and patient administration system. RESULTS: We identified 92 episodes in 90 patients. The main predisposing factors were being on an intensive care unit, having a central venous catheter, and (for neonates) prematurity. Central venous catheters were removed at a mean 1.8 days following candidaemia; 79% (37/47) were removed within 48 h (the audit standard). Identification and susceptibility tests were performed for 94.7% of isolates. All were susceptible to amphotericin B; 87% were susceptible to fluconazole. Antifungal treatment was started within 24 h of a positive blood culture in 84% of episodes. Initial antifungal therapy was appropriate in 95% (61/64) of treated cases. Most patients (81%) who survived or completed their intended course of treatment before death received at least 2 weeks treatment. However, only 45% of those transferred to other hospitals had accompanying guidance on the intended further duration of therapy. Thirty-day mortality was 41%. After adjustment for age, the presence of Candida-related complications was associated with an odds ratio for mortality of 6.5 (95% CI 1.2-36.5, p = 0.03). DISCUSSION: Overall the audit standards set by the BSMM and IDSA were met, and discrepancies did not lead to a change in outcome. Improved intravenous catheter care, a more pro-active approach to searching for complications, and improvement in the inter-hospital transfer process, will assist in reducing morbidity and mortality.

Adolescent↗

A case of Schöpf-Schulz-Passarge syndrome.

Schöpf-Schulz-Passarge syndrome (SSPS) is a rare ectodermal dysplasia characterized by hypodontia, hypotrichosis, nail dystrophy, palmoplantar keratoderma, and periocular and eyelid margin apocrine hidrocystomas. Several other skin tumours have been described in association with this syndrome, in particular, multiple palmoplantar eccrine syringofibroadenoma (ESFA). We report a case of SSPS with diffuse palmoplantar hyperkeratosis, which was shown by histology and immunocytochemistry to be due to ESFA.

Aged↗

Effects of Chlamydia trachomatis infection on the expression of natural killer (NK) cell ligands and susceptibility to NK cell lysis.

Natural killer (NK) cells are an important component of the immediate immune response to infections, including infection by intracellular bacteria. We have investigated recognition of Chlamydia trachomatis (CT) by NK cells and show that these cells are activated to produce interferon (IFN)-gamma when peripheral blood mononuclear cells (PBMC) are stimulated with CT organisms. Furthermore, infection of epithelial cell lines with CT renders them susceptible to lysis by human NK cells. Susceptibility was observed 18-24 h following infection and required protein synthesis by the infecting chlamydiae, but not by the host cell; heat or UV inactivated chlamydiae did not induce susceptibility to NK cell lysis. CT infection was also shown to decrease the expression of classical and non-classical major histocompatibility complex (MHC) molecules on infected cells, thus allowing recognition by NK cells when combined with an activating signal. A candidate activating signal is MICA/B, which was shown to be expressed constitutively on epithelial cells.

Bacterial Proteins↗

A randomized, placebo-controlled, double-blind trial of ondansetron in renal itch.

BACKGROUND: Renal itch is a relatively common and distressing problem for patients with chronic renal failure. Ondansetron, a serotonin type 3 receptor antagonist was developed for relief of chemotherapy induced nausea. Recently, anecdotal reports describe relief of renal itch with ondansetron. OBJECTIVES: We performed a double-blind randomized placebo-controlled trial to objectively assess the effectiveness of ondansetron in renal itch. PATIENTS AND METHODS: With approval from the local ethical committee, 24 patients on haemodialysis were enrolled in the trial. On a random basis 14 patients were blindly allocated to the ondansetron-placebo sequence and 10 to the placebo-ondansetron sequence. Baseline values for itch were obtained for 7 days before the treatment period and there was a 7-day washout between the treatment periods. During the treatment patients received either 8 mg of ondansetron three times a day or a placebo tablet three times a day for 2 weeks. Patients were asked to record the severity of their pruritus on a visual analogue scale (VAS) twice a day. At the end of the study patients were asked blindly which treatment they had preferred. RESULTS: Seventeen patients completed the trial. Pruritus decreased by 16% (95% CI: 0.5-32%) during active treatment and by 25% (95% CI: 9-41%) during treatment with placebo. The change in VAS scores during treatment with ondansetron (P = 0.04) and placebo (P = 0.01) were both significant. Eleven patients expressed a preference, seven for placebo and four for ondansetron. CONCLUSIONS: Our results show that ondansetron is no better than placebo in controlling renal itch.

Antipruritics↗

Clinical aspects and management of cytomegalovirus infection.

The previous article discussed recent advances in understanding the biology of HCMV infection. Here we discuss current approaches to the clinical management of HCMV disease, and how understanding the biology of the virus may affect these.

Acquired Immunodeficiency Syndrome↗

Vaccines against persistent DNA virus infections.

Persistent viruses present some particular problems for vaccine design. As for acute non-persistent viruses, the prime goal of a vaccine should be to prevent primary infection. Vaccines might also be used to modify the course of established persistent virus infections - so-called postinfective immunisation. This chapter deals with selected persistent DNA viruses, in particular the human herpes viruses.

Chickenpox↗

The incidence of hydroxyethyl starch-associated pruritus.

BACKGROUND: Pruritus due to hydroxyethyl starch (HES) is reported with a very variable frequency but appears to be relatively uncommon in the U.K. compared with other European countries. OBJECTIVES: To determine the frequency of HES-related pruritus in patients discharged from intensive care units (ICUs) in two U.K. hospitals. METHODS: A questionnaire survey was given to 253 patients after discharge from ICU. Questions were designed to exclude pre-existing skin disease and other causes of pruritus. RESULTS: One hundred and fifty-nine completed questionnaires were suitable for analysis. Seventeen of 135 (12.6%) subjects who had received HES reported itch, as did one of 24 who had not received HES. There was no apparent relationship between the occurrence of HES-related pruritus and either the surgical indication or the brand or volume of HES infused. CONCLUSIONS: HES-related pruritus is a problem that dermatologists need to recognize; however, its frequency in the U.K., when other causes of itch are excluded, appears to be lower than suggested in some previous reported studies.

Drug Eruptions↗

Paraneoplastic pemphigus: an association with fludarabine?

Paraneoplastic pemphigus is a relatively recently described immunobullous disease with characteristic features. We report three cases of paraneoplastic pemphigus in adult men with chronic lymphocytic leukaemia arising within a week of completion of treatment with fludarabine. In all cases, withdrawal of fludarabine and treatment of the blistering was associated with marked cutaneous improvement. Fludarabine, a synthetic nucleoside analogue, which has only been available in Britain since 1994, is known to be associated with autoimmune phenomena and may have been involved in the development of paraneoplastic pemphigus in these cases.

Antineoplastic Agents↗

Optimal sample preparation conditions for the determination of uranium in biological samples by kinetic phosphorescence analysis (KPA).

Kinetic phosphorescence analysis (KPA) is a proven technique for rapid, precise, and accurate determination of uranium in aqueous solutions. Uranium analysis of biological samples require dry-ashing in a muffle furnace between 400 and 600 degrees C followed by wet-ashing with concentrated nitric acid and hydrogen peroxide to digest the organic component in the sample that interferes with uranium determination by KPA. The optimal dry-ashing temperature was determined to be 450 degrees C. At dry-ashing temperatures greater than 450 degrees C, uranium loss was attributed to vaporization. High temperatures also caused increased background values that were attributed to uranium leaching from the glass vials. Dry-ashing temperatures less than 450 degrees C result in the samples needing additional wet-ashing steps. The recovery of uranium in urine samples was 99.2+/-4.02% between spiked concentrations of 1.98-1980 ng (0.198-198 microg l(-1)) uranium, whereas the recovery in whole blood was 89.9+/-7.33% between the same spiked concentrations. The limit of quantification in which uranium in urine and blood could be accurately measured above the background was determined to be 0.05 and 0.6 microg l(-1), respectively.

Humans↗

Reactivity of chloroethyl sulfides in the presence of a chlorinated prophylactic: a kinetic study by EPR/spin trapping and NMR techniques.

This study reports the kinetic reaction of a chlorinated glycoluril, 1,3,4,6-tetrachloro-7, 8-diphenyl-2,5-diimino glycoluril, also known as S-330, with butyl 2-chloroethyl sulfide (half-sulfur mustard, H-MG) and bis-(2-chloroethyl) sulfide (sulfur mustard, HD) using electron paramagnetic resonance (EPR)/spin trapping and nuclear magnetic resonance (NMR) techniques. Both H-MG and HD are highly reactive in water and are capable of alkylating a variety of critical target molecules. It is well known that compounds containing reactive chlorine are useful neutralizers of HD and other vesicating agents. Organic compounds containing a chloroamide group are generally preferred. Currently, the reactive mechanism of this chlorinated glycoluril with these chloroethyl sulfides has not been documented. The kinetic experiments were performed by adding the monofunctional sulfur mustard (H-MG) directly to the spin trap agent alpha-phenyl-N-tert-butylnitrone (PBN, pH 7.1). The intensity of the EPR spectra obtained from the resulting spin adduct (hyperfine coupling constants aN = 1.45 mT and abetaH = 0.225 mT) was sensitive to the rate at which the spin adduct was formed. Different concentrations of the chloroamide were added to the reaction mixtures of PBN and H-MG. The EPR spectra of separate identical reaction mixtures were recorded with the spectrometer set for kinetic experiments. The rate constant determined by EPR was 1.78 +/- 0.14 x 10(7) M(-1)s(-1). It was found that S-330 reacts 55 times faster than PBN. The results obtained for S-330 by EPR indicate that S-330 is an efficient scavenger of H-MG. Furthermore, a 13C-NMR chemical shift of 0.903 +/- 0.002 ppm was observed for the Cl-N-C-N-Cl carbon in S-330 after exposure to HD (1 mM). In addition, the decay of 13C-NMR resonance at 91.7 ppm chemical shift was observed in the presence of HD. The 13C-NMR data showed that the formation of the ethylene sulfonium ion usually found in the case of HD was not observed in the presence of S-330.

Amides↗

Response of normal human keratinocytes to sulfur mustard: cytokine release.

Cytokines play a major role in both acute and chronic inflammatory processes, including those produced by sulfur mustard (2,2'-dichlorodiethyl sulfide, HD). This study describes responses of normal human epidermal keratinocytes (NHEK) to HD, defined by interleukin-1beta (IL-1beta), IL-6, IL-8 and tumor necrosis factor alpha (TNF-alpha) release. Commercially available enzyme-linked immunosorbent assay (ELISA) kits were used to measure the cytokine release in NHEK during exposure to 100 and 300 microM of HD. Exposure to 100 microM HD increased the release of cytokines. The amounts of IL-8 and TNF-alpha present in cell suspensions increased up to 59-fold and 4-fold, respectively, above control levels when NHEK were exposed to 300 microM HD. Exposure of NHEK to 300 microM HD had a highly variable effect on the release of IL-1beta, where sometimes the secretion of IL-1beta increased above baseline level and at other times it decreased in cell suspensions. Supernatants were collected from cell culture flasks 24 h after exposure of 100 and 300 microM HD and significantly increased levels of IL-6 were observed. Interleukin-6 was released in a concentration-dependent manner, 3.6-fold up to 8.4-fold, respectively, in supernatant. These pro-inflammatory mediators IL-1beta, IL-8, TNF-alpha and IL-6 may play an important role in HD injury. The present findings suggest that the cytokine changes detected could be used as potential biomarkers of cutaneous vesicant injury.

Biomarkers↗

Renal itch.

Renal itch is localized or generalized itch, affecting patients with chronic renal failure, where there is no primary skin disease and no systemic or psychological dysfunction that might cause pruritus. It does not result from raised serum urea levels. The prevalence of renal itch has increased with the growing population in chronic renal failure and is a considerable cause of morbidity. The prevalence of itch increases with deteriorating renal function but does not improve significantly with dialysis. The pruritus is independent of duration of dialysis or cause of renal failure. The aetiology of renal itch is unclear. There is little evidence of a major role for histamine and antihistamines are rarely beneficial. Hyperparathyroidism, abnormal cutaneous innervation and endogenous opioids have been postulated as contributory factors. Treatment of renal itch is difficult. Naltrexone, oral activated charcoal, UVB phototherapy and ondansetron have been shown to be effective. Topical capsaicin may be of benefit in patients with localized pruritus. The definitive treatment for renal itch remains renal transplantation.

Humans↗