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Biomedical subjects

A Austin

Publications and source records attributed to A Austin.

At least 19 recordsLinked to original sources

An in vitro study of antimicrobial activity and efficacy of iodine-generating hydrogel dressings.

OBJECTIVE: To determine the antimicrobial activity and efficacy of different formulations of novel bioxygenating hydrogel dressings (which deliver both iodine and oxygen into the wound) against various target organisms by means of an in vitro test system that more effectively mimics the conditions encountered when dressings are in contact with wounds. METHOD: Three bioxygenating hydrogels were tested: Oxyzyme, which releases low levels of iodine into the wound, and Iodozyme 402 and Iodozyme 401, which release higher levels of iodine, with Iodozyme 402 releasing twice the amount of 401. Cellulose filter disks (n = 32) were inoculated with indicator species and placed equidistant from each other as a matrix onto agar test beds. Cut squares of control or test dressings were placed on top of each disk. Kill curves were constructed from determinations of the numbers of survivors (log cfu per disk) over time by removing disk samples at various time points. RESULTS: Significant differences (p < 0.05) were observed between the controls and test samples. The order of sensitivity for Oxyzyme was Fusobacterium nucleatum, Bacteroides fragilis, Propionibacterium acnes, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA), Candida albicans and Pseudomonas aeruginosa. The order of efficacy of the three hydrogel dressings (Iodozyme 402, followed by Iodozyme 401 and then Oxyzyme) was the same regardless of the target species. CONCLUSION: The novel hydrogel skin surface wound dressings are broad-spectrum in activity, encompassing antibiotic-resistant organisms, anaerobes and yeasts; their antimicrobial function appears to be rapidly effective.

Administration, Cutaneous↗

Using Ecosan sludge for crop production.

This paper presents the microbial risks associated with the reuse of Ecosan sludge in agriculture. Sludge from KwaZulu Natal Province in South Africa with a helminth ova content of 30 HO/g TS, faecal coliforms of 10(6) CFU/g TS, faecal streptococci of 10(6) CFU/g TS and Salmonella spp. of 10(5) CFU/g TS was used for this purpose. Applying different rates of sludge to spinach and carrots resulted in an increase in bacterial and helminth ova counts in crops as the quantity of sludge increased. The helminth ova content in crops was always greater in leaves than in stems, with a content varying from 2 to 15 HO/g TS for spinach with sludge application rates of 0-37.5 ton/ha and from 2-8 HO/g TS for carrot crops with sludge application rates varying from 0-35 ton/ha. Nevertheless, viability in crops was 20-25%, reducing the risk of disease. Consequently, the development of an Ecosan sludge revalorisation standard is considered important. Some recommendations are made taking into account the characteristics of the sludge as well as conditions in rural areas.

Animals↗

Nodular regenerative hyperplasia of the liver and coeliac disease: potential role of IgA anticardiolipin antibody.

Nodular regenerative hyperplasia (NRH) of the liver is a rare disorder that is often associated with connective tissue disorders, haematological malignancy, or drugs, and is a cause of non-cirrhotic portal hypertension. We describe two cases of NRH in individuals with adult coeliac disease and IgA anticardiolipin antibodies. We discuss the potential impact of this observation on the understanding of the pathogenesis of NRH.

Adult↗

Oesophageal cancer and cachexia: the effect of short-term treatment with thalidomide on weight loss and lean body mass.

BACKGROUND: Cachexia is common in patients with advanced cancer and has a direct impact on well-being and mortality. AIM: To test the hypothesis that thalidomide can promote weight gain and lean body mass in patients with advanced oesophageal cancer. METHODS: In an open-label study, 11 patients with non-obstructing and inoperable oesophageal cancer were established on an isocaloric diet for 2 weeks, followed by 2 weeks on thalidomide, 200 mg daily. The primary end-points were weight change and lean body mass. Secondary end-points were quality of life and changes in resting energy expenditure. RESULTS: Ten patients completed the study protocol. The average caloric intake remained the same throughout the study period in all patients. Nine of 10 patients (95% confidence interval, 0.60, 0.98) lost weight on diet alone. The mean weight gain on thalidomide in the following 2 weeks was 1.29 kg (median, 1.25 kg). A similar trend was shown in the lean body mass. Eight of nine patients (95% confidence interval, 0.57, 0.98) initially lost lean body mass on diet alone (missing data in one patient). The mean gain in lean body mass on thalidomide in the following 2 weeks was 1.75 kg (median, 1.33 kg). CONCLUSIONS: Thalidomide treatment appeared to reverse the loss of weight and lean body mass over the 2-week trial period.

Aged↗

Contraceptive devices and the medical devices directive.

The Medical Devices Agency (MDA), an executive agency of the Department of Health, has responsibility for the safety of medical devices within the UK. The MDA is responsible for enforcing the European Medical Devices Directive (MDD) within the UK. Contraceptive devices such as copper-containing IUDs and condoms are regulated by the MDD, and this brief report is an introduction to it.

Consumer Product Safety↗

Production and perception of "verbosity" in younger and older adults.

Older adults produced more off-topic speech (OTS) than younger adults during autobiographical interviews in previous studies, a finding attributed to age-related deficits in inhibiting irrelevant information. In this study, older adults produced more OTS than younger adults for autobiographical topics, but not for picture descriptions. A 2nd sample of younger and older participants rated older adults' story quality more positively than that of younger adults, a problematic finding for the inhibitory deficit explanation. Rater age affected ratings of how focused the speech was on the topic, suggesting age differences in criteria for OTS. These findings are consistent with the Pragmatic Change hypothesis, which maintains that older adults adopt communicative goals that emphasize the significance of life experiences rather than conciseness in their personal narratives.

Adult↗

Stereological estimates of nuclear number in human ventricular cardiomyocytes before and after birth obtained using physical disectors.

Design-based stereology is employed to estimate total numbers of myocyte nuclei and mean myocyte volume per nucleus in ventricles of fetal and early postnatal human hearts. Organs were collected postmortem from subjects varying in age from 16 gestational wk to 40 postnatal wk. Numbers of myocyte nuclei per unit volume of ventricle were estimated using physical disectors (parallel pairs of sections). Absolute numbers were calculated by multiplying nuclear packing densities by ventricular volumes estimated from ventricular mass and tissue density. Volumes per nucleus were obtained via estimates of the combined volumes of all myocytes (or of the myocardium as a whole) and the numbers of myocyte nuclei. The findings showed that numbers of myocyte nuclei increase linearly from 16 wk towards term. They were also consistent with the notion that hyperplasia ceases abruptly at birth or soon afterwards. The net rate of production of myocyte nuclei was about 38 x 10(7)/wk (2.3 million nuclei/h). The total volume of myocytes continued to expand in the same way from 16 wk to at least 35 wk of gestation. Published studies on the incidence of binucleate myocytes during early postnatal growth of the ventricles of rats suggest that the volume of a myocyte doubles prior to nuclear division. Prenatal growth in the human heart is consistent with this mechanism. Myocardial hypertrophy after birth must occur by cellular hypertrophy without karyokinesis.

Cell Nucleus↗

From guidelines to decision support in the management of asthma.

Asthma is a common chronic disease of the lungs caused by inflammation of the airways affecting 6-7% of the population. Asthma is becoming commoner and there is evidence of under-diagnosis and poor management. Guidelines have been developed aimed at improving quality of care and in reducing social costs of asthma. The paper discusses an approach to implementing guidelines through decision-support system in primary care, based on methods developed in the AIM GAMES-II project. We also describe a prototype system that has been developed and a programme of clinical evaluation.

Adult↗

A stereological method for estimating the total number of ventricular myocyte nuclei in fetal and postnatal hearts.

An experimental protocol is presented for obtaining efficient estimates of the total numbers of myocyte nuclei in the ventricles of human hearts from archival collections. Hearts were collected postmortem from fetuses at 31-42 weeks of gestation and infants at 7 days-9 months postnatal age. Ventricles from normal and abnormal subjects were examined. Numbers of myocyte nuclei per unit volume of myocardium were estimated separately for left and right ventricles using a design-based stereological device, the physical disector (parallel pairs of sections). Absolute numbers were calculated by multiplying nuclear packing densities by myocardial volume. The latter was estimated from ventricular mass and the percentage of ventricle occupied by myocardium. The findings, albeit preliminary, suggest that (1) myocyte number may rise during the last trimester of gestation, (2) postnatal ventricular growth is probably hypertrophic and/or interstitial rather than hyperplastic and (3) whilst absolute numbers are greater in the left ventricle, the pattern of growth is similar in both ventricles. Nuclear numbers found in 2 abnormal hearts (1 from a case of sudden infant death) tended to be lower than normal.

Cell Count↗

Roles of insulin resistance and beta-cell dysfunction in the pathogenesis of glucose intolerance in cystic fibrosis.

The roles of insulin deficiency and insulin resistance in the pathogenesis of glucose intolerance in cystic fibrosis (CF) were evaluated in eight patients (aged 16.5 +/- 1.9 yr), four with normal glucose tolerance (NGT) and four with impaired glucose tolerance (IGT), and in seven healthy control (CN) subjects. First and second phase insulin secretions were evaluated during a hyperglycemic clamp. Hepatic glucose production (HGP) and insulin-stimulated glucose disposal were measured using [6,6-2H2]glucose and a stepwise hyperinsulinemic-euglycemic clamp. First and second phase insulin levels were significantly lower in both groups of CF patients compared with control values. There was an inverse relationship between glycohemoglobin level and first phase insulin (r = -0.81; P = 0.015) and second phase insulin (r = -0.97; P < 0.001). During the hyperglycemic clamp, the insulin sensitivity index was lower in CF-IGT, but not CF-NGT, compared with control values (6.66 +/- 1.79, 12.82 +/- 1.61, and 13.02 +/- 1.78 mumol/kg.min/pmol.L, respectively; P < 0.05). Basal HGP and fasting plasma glucose were higher in CF vs. CN [24.8 +/- 2.9 vs. 16.9 +/- 1.4 mumol/kg.min (P = 0.036) and 5.8 +/- 0.2 vs. 5.4 +/- 0.1 mmol/L (P = 0.035), respectively]. During the hyperinsulinemic euglycemic clamp, insulin-stimulated glucose disposal was significantly lower in CF-IGT (45.68 +/- 4.87 mumol/kg.min) vs. CF-NGT (78.99 +/- 1.34 mumol/kg.min) and CN (71.74 +/- 6.88 mumol/kg.min). Insulin sensitivity was lower in CF-IGT vs. CF-NGT (7.04 +/- 0.86 and 14.38 +/- 0.84 mumol/kg.min/pmol.L; P < 0.05). We conclude that 1) glycohemoglobin is a strong correlate of insulin deficiency in CF; and 2) glucose intolerance in this group of CF patients occurred as a consequence of concomitant insulin deficiency and insulin resistance.

Adolescent↗

The relationship of physical fitness to lipid and lipoprotein(a) levels in adolescents with IDDM.

OBJECTIVE--Increased physical activity and physical fitness are recommended therapeutic modalities in addition to insulin and diet in the management of children with IDDM. The aim of this study was to assess the fitness levels of adolescents with IDDM compared with healthy control subjects and to evaluate the relationship between physical fitness and metabolic control. RESEARCH DESIGN AND METHODS--We studied 59 patients with IDDM, 28 boys and 31 girls, age 15.6 +/- 2.5 yr, duration of diabetes 7.6 +/- 3.5 yr, HbA1 10.6 +/- 2.1% (mean +/- SD), and compared them with 18 healthy, nondiabetic control subjects, 9 boys and 9 girls, matched for age, BMI, and Tanner stage. Physical fitness was measured by VO2max during progressive bicycle ergometry. HbA1 was used to determine glycemic control. Lipid profile included fasting total cholesterol, HDL, LDL, Lp(a), and TG levels. RESULTS--Patients with IDDM had lower VO2max levels than control subjects (33.7 +/- 7.0 vs. 41.0 +/- 10.4 ml.kg-1.min-1, P = 0.001). Males with IDDM had lower VO2max than male control subjects, but diabetic and control females showed no difference. In IDDM patients, VO2max correlated inversely with HbA1, insulin dose, cholesterol, LDL, TGs, and Lp(a), but did not correlate with HDL, which correlated inversely with BMI. CONCLUSIONS--We conclude that the state of physical fitness is an important correlate of lipid levels and Lp(a) in adolescents with IDDM. We speculate that higher physical fitness levels in adolescents with IDDM may decrease the risk of CVD through modulating lipid levels.

Adolescent↗

Cyclic AMP produces desensitization of prostacyclin and adenosine A2 receptors in hybrid cell lines but does not affect Gs function.

Prostacyclin and adenosine A2 receptors stimulate adenylate cyclase activity in the related somatic hybrid cell lines NG108-15 and NCB20. The role of cAMP in the desensitization of these receptors has been examined. Pretreatment for 17 h with forskolin or 8-bromo-cAMP had the same effect in both cell lines. There was no change in the response to sodium fluoride or forskolin, suggesting that the function of Gs and adenylate cyclase were unaffected by increased levels of cAMP. Receptor responses were affected however; the maximum response to N-ethylcarboxamidoadenosine (an A2 receptor agonist) was reduced by 30-40%, there was a small but consistent shift to the right of the dose-response curve for iloprost (a stable analogue of prostacyclin) and [3H]iloprost binding studies revealed a loss of prostacyclin receptors. However, the loss of receptor responsiveness was much smaller than that which occurs following pretreatment with prostacyclin or adenosine A2 receptor agonists (Keen et al. (1989) Biochem. Pharmacol. 38, 3827-3833; Kelly et al. (1990) Br. J. Pharmacol. 99, 309-316) suggesting that cAMP may not play a major role in agonist mediated desensitization.

8-Bromo Cyclic Adenosine Monophosphate↗