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Biomedical subjects

A Voss

Publications and source records attributed to A Voss.

At least 127 records · Page 7Linked to original sources
PubMed1997

No time for handwashing!? Handwashing versus alcoholic rub: can we afford 100% compliance?

Handwashing is the most important and least expensive measure to prevent transmission of nosocomial infections. However, compliance rarely exceeds 40% under study conditions. Alcoholic hand disinfection (AHD) generally is used in Europe. In contrast, handwashing with medicated soap is practiced most frequently in the United States. Healthcare workers often explain the failure to comply with handwashing or AHD as due to the limited time available for this practice. We calculated a time consumption for handwashing and AHD in a representative model intensive-care unit with 12 healthcare workers, based on different compliance levels (40%, 60%, and 100%), duration of handwashing (40-80 seconds), and AHD (20 seconds). Comparing the extremes of our model, given 100% compliance, handwashing consumes 16 hours of nursing time per day shift, whereas AHD from a bedside dispenser requires only 3 hours (P = .01). We conclude that 100% compliance with handwashing may interfere with patient care and parltly explains the low compliance. In contrast, AHD, with its rapid activity, superior efficacy, and minimal time commitment, allows 100% healthcare-worker compliance without interfering with the quality of patient care.

Alcohols↗
PubMed1997

Fecal carriage of vancomycin-resistant enterococci in hospitalized patients and those living in the community in The Netherlands.

In order to determine the prevalence of vancomycin-resistant enterococci (VRE) in The Netherlands, 624 hospitalized patients from intensive care units or hemato-oncology wards in nine hospitals and 200 patients living in the community were screened for VRE colonization. Enterococci were found in 49% of the hospitalized patients and in 80% of the patients living in the community. Of these strains, 43 and 32%, respectively, were Enterococcus faecium. VRE were isolated from 12 of 624 (2%) and 4 of 200 (2%) hospitalized patients and patients living in the community, respectively. PCR analysis of these 16 strains and 11 additional clinical VRE isolates from one of the participating hospitals revealed 24 vanA gene-containing, 1 vanB gene-containing, and 2 vanC1 gene-containing strains. All strains were cross-resistant to avoparcin but were sensitive to the novel glycopeptide antibiotic LY333328. Genotyping of the strains by arbitrarily primed PCR and pulsed-field gel electrophoresis revealed a high degree of genetic heterogeneity. This underscores a lack of hospital-driven endemicity of VRE clones. It is suggested that the VRE in hospitalized patients have originated from unknown sources in the community.

Anti-Bacterial Agents↗
PubMed1997

Wooden sticks as the source of a pseudoepidemic of infection with Rhizopus microsporus var. rhizopodiformis among immunocompromised patients.

Wooden sticks used to suspend feces obtained for surveillance cultures were found to be the source of Rhizopus microsporus var. rhizopodiformis causing a pseudo-outbreak among 17 immunocompromised patients cared for in three different wards. Nonsterile wooden products should therefore not be used for collecting, handling, and processing specimens for microbiological examination.

Cross Infection↗
PubMed1997

Psychophysiologic predictors of weaning from mechanical ventilation in chronic bronchitis and emphysema.

This study identified psychophysiologic variables related to successful weaning in 27 ventilator-dependent patients with chronic bronchitis and emphysema (CBE) from two long-term care pulmonary-specialty hospitals in South Central Florida. Subjects were studied from admission until weaning occurred (successful weaning without mechanical ventilation) or until they were transferred without being weaned or died (unsuccessful weaning). The study subjects, 15 males and 12 females, ranged in age from 56 to 89. Baseline data on the variables (age, mastery, hope, social support, dyspnea, and rapid shallow breathing index [RSBI]) were not statistically significant by gender. The logistic regression model identified mastery and RSBI to be the best predictors of successful weaning (model chi 2 = 16.33, df = 2, and p value = .0003; prediction rate 82%).

Aged↗
PubMed1997

[A method for measuring QT and T duration and beat to beat variability].

The QT interval duration is an important non-invasive electrophysiological parameter that reflects ventricular depolarization and repolarization time. A knowledge of QT variability also provides specific information on the normal and pathological ventricular myocardium, and the influence of the autonomic nervous system. A numerical algorithm was developed for measuring QT interval and T-wave duration in the surface electrocardiogram. In comparison with numerous other approaches, this method calculates these durations without averaging of QRS complexes on a beat-to-beat basis. The main aim of this study was to assess the efficacy of this method for characterizing cardiac diseases. In 6 patients with hypertrophic cardiomyopathy and a control group of 5 healthy, age-matched subjects, different interval durations were calculated. In contrast to the mean QT interval duration, only the T-wave duration differed significantly between the two groups.

Algorithms↗
PubMed1997

The influence of adaptation and stochastic fluctuations on spontaneous perceptual changes for bistable stimuli.

Spontaneous perceptual change was studied by measuring the probabilities of the first two spontaneous pattern switches as a function of time following the onset of a bistable apparent quartet for which either horizontal or vertical motion is perceived. Contrary to the classical satiation hypothesis (Köhler & Wallach, 1944), differential time-dependent adaptation of the perceived compared with the unperceived motion directions was not necessary to account for the first spontaneous switch. In addition, adaptation of the perceived motion accompanied by recovery from adaptation of the unperceived motion was not necessary to account for the increased probability of the second spontaneous switch. It was concluded that regardless of possible adaptation effects, stochastic fluctuations are necessary for the actual reversal of activation levels that produces the spontaneous switch. When the difference in detector activation is reduced by differential adaptation of competing motion detectors (or by the occurrence of a prior spontaneous pattern change), smaller stochastic fluctuations are sufficient to reverse the relative activation of competing detectors. Thus, adaptation can increase the probability of spontaneous switches without directly causing them.

Adaptation, Ocular↗
PubMed1996

[The changing pattern of Candida infections: different species and increased resistance].

The incidence of invasive infections with Candida has strongly increased during the last few decades. Candida is now one of the commonest hospital pathogens. Many infections are nowadays caused by other species than C. albicans, notably C. tropicalis, C. krusei and C. glabrata. Particularly in HIV seropositive patients the yeast may develop resistance to fungistatic drugs. The altered species frequency and the resistance appear to be caused by the use of fungistatic agents of the imidazole group. To counter these developments the choice of antifungal therapeutics should be made very carefully.

Antifungal Agents↗
PubMed1996

Occurrence of yeast bloodstream infections between 1987 and 1995 in five Dutch university hospitals.

The aim of this study was to identify retrospectively trends in fungal bloodstream infections in The Netherlands in the period from 1987 to 1995. Results of over 395,000 blood cultures from five Dutch university hospitals were evaluated. Overall, there were more than 12 million patient days of care during the nine-year study period. The rate of candidemia doubled in the study period, reaching an incidence of 0.71 episodes per 10,000 patient days in 1995. The general increase in candidemia was paralleled by an increase in non-Candida albicans bloodstream infections, mainly due to Candida glabrata. However, more than 60% of the infections were caused by Candida albicans. Fluconazole-resistant species such as Candida krusei did not emerge during the study period. The increasing rate of candidemia found in Dutch university hospitals is similar to the trend observed in the USA, but the rate is lower and the increase is less pronounced.

Antifungal Agents↗
PubMed1996

Familial and genetic influences on heart rate variability.

The authors tested the hypothesis of a genetic influence on heart rate variability (HRV). This genetic influence was assessed in 62, twin pairs (30 monozygotic, 32 dizygotic). From all twins, long-term electrocardiographic records were obtained, edited, and analyzed. Heart rate variability analysis was performed on the basis of parameters from time-domain, frequency-domain, and nonlinear dynamics. First, the parameter distances between the two twins of a pair and between one of the two and a third randomly selected person of another age-matched twin pair (ST1) were compared. Second, the parameter distances between the two twins and the averaged parameter distances of these two twins to all other age-matched persons (ST2) were compared. Finally, the averaged differences in parameter values between monozygotic and dizygotic age-matched twin pairs were compared. For statistical analysis, the nonparametric Wilcoxon's matched-pair signed rank test and parametric t-test for paired samples were used. Twin pairs show a significant lower difference in parameter values than other randomly selected and age-matched couples (P < .001 in ST1 and ST2). This reflects a considerable familial influence. Most parameters of the time-domain, none of the frequency-domain, and half of the nonlinear dynamics show significant differences between twin pairs and nontwin pairs. As a result of the comparison between monozygotic and dizygotic twin pairs, a significant lower parameter difference in the monozygotic pairs (P < .05) is found. These results suggest that there is a genetic component in heart rate generation and HRV, in addition to family environmental influences. Analysis of HRV might become a useful method in phenotyping severe genetic changes in cardiovascular diseases.

Adult↗
PubMed1996

Prospective cross-over comparisons of three low-density lipoprotein (LDL)-apheresis methods in patients with familial hypercholesterolaemia.

We prospectively compared effectiveness, selectivity and biocompatibility of three LDL-apheresis methods, immunoadsorption (IMAL), dextran sulphate adsorption (DSAL) and heparin-induced extracorporeal LDL precipitation (HELP). Seven patients with familial hypercholesterolaemia were treated twice with each method in random sequence. Reduction in atherogenic lipoproteins was without significant difference: LDL -60% to -75%, VLDL -20% to -30%, triglycerides -20% to -42%. High-density lipoprotein (HDL)-cholesterol was reduced by IMAL only (-27%, P < 0.05); DSAL and HELP did not decrease HDL. Total plasma protein reduction was 13-15% with each method, indicating unselectivity. Albumin was significantly decreased by IMAL (-15%, P < 0.05) but not by the other methods. DSAL and HELP reduced fibrinogen (-40%, -58%, P < 0.0001) and other clotting factors. IMAL had almost no effect on coagulation. The white blood cell count did not change. C3 and C4 complement were decreased (-20% to -46%) by all methods. C5a complement did not increase in systemic blood, but was increased in the extracorporeal circulation of IMAL (+200%) and HELP (+150%). Plasma PMN elastase rose in all methods (+200%) indicating neutrophile degranulation. In conclusion, in this short-term study of a small patient population, effectiveness of the three LDL-apheresis methods was similar, but selectivity and biocompatibility were different. The therapeutic relevance of these differences for long-term treatment remains to be elucidated.

Blood Component Removal↗