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Biomedical subjects

E Dietz

Publications and source records attributed to E Dietz.

At least 19 recordsLinked to original sources
PubMed2000

HIV-related nontuberculous mycobacterial infection: incidence, survival analysis and associated risk factors.

To evaluate the incidence and survival time for AIDS-patients affected by different stages of nontuberculous mycobacterial (NTM) infection we performed a retrospective study. Data of 1540 hospitalised AIDS-patients was analyzed with respect to survival time and incidence rates. The overall incidence rate of NTM following AIDS was 16.6/100 person-years (PY), with an increase from 12.1/100PY (1987-1990) to 18.9/100PY (1991-1994). Antiretroviral therapy (ART) and toxoplasmosis prophylaxis reduced the risk of NTM disease whereas CD4 cells <40/ microl at time of the first AIDS defining illness led to a 2.5 fold higher risk. Pneumocystis carinii pneumonia (PCP), wasting syndrome and PCP prophylaxis increased the risk of progression from colonization to dissemination. Cryptococcus neoformans infection, wasting syndrome, PCP prophylaxis and CD4 cells <40/ microl were linked to immediate NTM dissemination. Though the incidence of NTM dissemination increased by the factor 1.56 in 1991-1994, survival did not differ between patients with and without NTM infection.

AIDS-Related Opportunistic Infections↗
PubMed1999

The relationship between alcohol consumption, health indicators and mortality in the German population.

BACKGROUND: The patterns of total alcohol, beer and wine consumption were evaluated in the German National Health Surveys. The impact of these habits on cardiovascular and all-cause mortality as well as cardiovascular risk factors and liver disease parameters was estimated. METHODS: Independent representative samples of the German population (15,400 people), and regional samples of the Berlin-Spandau population (2,370 in total), aged 25-69 years, were analysed. The amount and frequency of alcohol consumption was assessed with standardized questionnaires. Biochemical analyses included serum lipids and gamma-glutamyl-transpeptidase (Gamma GT). Multiple analyses of variance were used to determine the relationship between alcohol intake and biochemical parameters. A mortality follow-up of about 7 years was conducted for the Berlin-Spandau population. Proportional hazard models were used to estimate hazard ratios (HR) for all-cause and cardiovascular mortality. RESULTS: Over 80% of men and 55% of women in Germany drink alcohol on a regular base. The majority of the consumers (65% of men, 87% of women) are light (1-20 g/day) or moderate (21-40 g/day) drinkers. Higher serum high density lipoprotein (HDL)-cholesterol and Gamma GT levels were observed with increasing alcohol intake. In light and moderate drinkers no significant relationship was seen with non-HDL-cholesterol, triglycerides, blood pressure and body mass index, compared to teetotallers. Men who consumed 1-20 g alcohol/day had a significantly lower all-cause and cardiovascular mortality. As compared to nondrinkers, the risk was almost 50% lower. CONCLUSION: The results suggest that light (and possibly moderate) alcohol consumption reduces the risk of cardiovascular and total mortality risk and is favourably related to HDL-cholesterol.

Adult↗
PubMed1999

Effects of anticoagulant, processing delay, and assay method (branched DNA versus reverse transcriptase PCR) on measurement of human immunodeficiency virus type 1 RNA levels in plasma.

We conducted two studies to determine the potential influence of delays in blood processing, type of anticoagulant, and assay method on human immunodeficiency virus type 1 (HIV-1) RNA levels in plasma. The first was an experimental study in which heparin- and EDTA-anticoagulated blood samples were collected from 101 HIV-positive individuals and processed to plasma after delays of 2, 6, and 18 h. HIV-1 RNA levels in each sample were then measured by both branched-DNA (bDNA) and reverse transcriptase PCR (RT-PCR) assays. Compared to samples processed within 2 h, the loss (decay) of HIV-1 RNA in heparinized blood was significant (P < 0.05) but small after 6 h (bDNA assay, -0.12 log(10) copies/ml; RT-PCR, -0.05 log(10) copies/ml) and after 18 h (bDNA assay, -0.27 log(10) copies/ml; RT-PCR, -0.15 log(10) copies/ml). Decay in EDTA-anticoagulated blood was not significant after 6 h (bDNA assay, -0.002 log(10) copies/ml; RT-PCR, -0.02 log(10) copies/ml), but it was after 18 h (bDNA assay, -0.09 log(10) copies/ml; RT-PCR, -0.09 log(10) copies/ml). Only 4% of samples processed after 6 h lost more than 50% (>/=0.3 log(10) copies/ml) of the HIV-1 RNA, regardless of the anticoagulant or the assay that was used. The second study compared HIV-1 RNA levels in samples from the Multicenter AIDS Cohort Study (MACS; samples were collected in heparin-containing tubes in 1985, had a 6-h average processing delay, and were assayed by bDNA assay) and the British Columbia Drug Treatment Program (BCDTP) (collected in EDTA- or acid citrate dextrose-containing tubes in 1996 and 1997, had a 2-h maximum processing delay, and were assayed by RT-PCR). HIV-1 RNA levels in samples from the two cohorts were not significantly different after adjusting for CD4(+)-cell count and converting bDNA assay values to those corresponding to the RT-PCR results. In summary, the decay of HIV-1 RNA measured in heparinized blood after 6 h was small (-0.05 to -0.12 log(10) copies/ml), and the minor impact of this decay on HIV-1 RNA concentrations in archived plasma samples of the MACS was confirmed by the similarity of CD4(+)-cell counts and assay-adjusted HIV-1 RNA concentrations in the MACS and BCDTP.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Survival of vancomycin-resistant and vancomycin-susceptible enterococci on dry surfaces.

We compared the abilities of Enterococcus faecium strains (three vancomycin-resistant enterococci [VRE] and five vancomycin-susceptible enterococci [VSE]) and Enterococcus faecalis strains (one VRE and 10 VSE) to survive under dry conditions. Bacterial suspensions of the strains were inoculated onto polyvinyl chloride and stored under defined conditions for up to 16 weeks. All strains survived for at least 1 week, and two strains survived for 4 months. A statistical model was used to distribute the 19 resulting survival curves between two types of survival curves. The type of survival curve was not associated with the species (E. faecalis versus E. faecium), the source of isolation (patient versus environment), or the susceptibility to vancomycin (VRE versus VSE). Resistance to dry conditions may promote the transmissibility of a strain, but VRE have no advantages over VSE with respect to their ability to survive under dry conditions.

Anti-Bacterial Agents↗
PubMed1998

Recent developments in computer-assisted analysis of mixtures.

This paper reviews recent developments in the area of computer-assisted analysis of mixture distributions (C.A.MAN). Given a biometric situation of interest in which, under homogeneity assumptions, a certain parametric density occurs, such as the Poisson, the binomial, the geometric, the normal, and so forth, then it is argued that this situation can easily be enlarged to allow a variation of the scalar parameter in the population. This situation is called unobserved heterogeneity. This naturally leads to a specific form of nonparametric mixture distribution that can then be assumed to be the standard model in the biometric application of interest (since it also incorporates the homogeneous situations as a special case). Besides developments in theory and algorithms, the work focuses on developments in biometric applications such as meta-analysis, fertility studies, estimation of prevalence under clustering, and estimation of the distribution function of survival time under interval censoring. The approach is nonparametric for the mixing distribution, including leaving the number of components (subpopulations) of the mixing distribution unknown.

Animals↗
PubMed1997

Impact of biological factors on the interpretation of bovine trypanosomosis serology.

A total of 457 cattle from dairy farms in Mukono County, Uganda, were investigated for Trypanosoma antibodies by ELISA. The objective of the study was to identify explanatory covariate factors for seropositivity among nine farm-specific and four animal-specific variables. We used logistic regression models for parasitological and serological outcome variables and then compared the adjusted odds ratios for explanatory factors between the models. Age is positively correlated with seropositivity but not with the detection of the parasite. Therefore, age group-specific cut-off values were established using mixture-distribution analysis. This procedure, as well as a mixture-distribution-derived cut-off value for the total sample, resulted in a greater relative efficiency of the ELISA as compared to conventional interpretation (cut-off value defined using non-exposed negative controls). The relevance of age and other biological factors for the serological status is briefly discussed.

Age Factors↗
PubMed1997

Survival of Acinetobacter baumannii on dry surfaces.

Acinetobacter spp. have frequently been reported to be the causative agents of hospital outbreaks. The circumstances of some outbreaks demonstrated the long survival of Acinetobacter in a dry, inanimate environment. In laboratory experiments, we compared the abilities of five Acinetobacter baumannii strains, three Acinetobacter sp. strains from the American Type Culture Collection (ATCC), one Escherichia coli ATCC strain, and one Enterococcus faecium ATCC strain to survive under dry conditions. Bacterial solutions of the 10 strains were inoculated onto four different material samples (ceramic, polyvinyl chloride, rubber, and stainless steel) and stored under defined conditions. We investigated the bacterial counts of the material samples immediately after inoculation, after drying, and after 4 h, 1 day, and 1, 2, 4, 8, and 16 weeks of storage. A statistical model was used to distribute the 40 resulting curves among four types of survival curves. The type of survival curve was significantly associated with the bacterial strain but not with the material. The ability of the A. baumannii strains to survive under dry conditions varied greatly and correlated well with the source of the strain. Strains isolated from dry sources survived better than those isolated from wet sources. An outbreak strain that had caused hospital-acquired respiratory tract infections survived better than the strains from wet sources, but not as well as strains from dry sources. Resistance to dry conditions may promote the transmissibility of a strain, but it is not sufficient to make a strain an epidemic one. However, in the case of an outbreak, sources of Acinetobacter must be expected in the dry environment.

Acinetobacter↗
PubMed1995

[Field study to obtain Legionella-free water from showers and sinks of a transplantation unit by a system of water filters].

The efficiency of filters for elimination of Legionella was examined in a ten month field study. Showers and sinks of twelve patient rooms were equipped with nylon 66-polyamid filters. Before filtration the total number of colonies was very high with an arithmetical mean of 1131 cfu/ml. This could be reduced by filtration at the sinks (mean = 205 cfu/ml). After equipping showers with filters we found a significant increase in the total number of colonies (mean = 1961 cfu/ml). In non-filtered water we found Legionella in nearly 90% of the 648 samples, the concentration extended to 300 cfu/ml (mean = 51 cfu/ml). After filtration the concentration of Legionella was up to 280 cfu/ml in 7.3% of the 665 samples. We calculated a logistic regression model to examine the effects of the age of the filters and the duration of their use since the last sterilization. These parameters were calculated from the time of the break through or retrograde contamination with Legionella. There were clear differences between shower and sink filters. Assuming a 5% probability of break through or retrograde contamination with Legionella, the sink filters should be sterilized every 3 weeks without regards to the age of the filters. In contrast the shower filters may be used for 3 weeks if they are sterilized weekly. If weekly sterilization is not feasible they should be used for 2 weeks only. In our study it was not possible to achieve Legionella-free water by changing either the frequency of sterilization or the age of the filters.

Baths↗
PubMed1994

Visual evoked potentials in Alzheimer's disease: investigations in a PET-defined collective.

Intravital diagnosis of Alzheimer's disease (AD) based clinical and neuropsychological findings alone does not allow sufficient differentiation from other disorders such as vascular dementia. Positron emission tomography (PET) secures intravital diagnosis with high accuracy by determination of a typical metabolic pattern. Numerous publications have proposed visual evoked potentials (VEP) for the detection of AD. In a collective of 15 patients with probable AD according to NINCDS/ADRDA criteria and the typical metabolic pattern of AD, we examined pattern reversal and flash VEPs. The results were compared to those of an age-matched collective of patients without impairment of memory. Neither pattern reversal nor flash VEP were correlated to severity of dementia as determined by the mini-mental status examination (MMSE). The positive results of other investigators are probably due to different patient selection criteria which do not include findings of cerebral glucose metabolism in the definition of AD.

Aged↗
PubMed1991

[Longitudinal study of colophony exposed workers and control probands].

267 solderers and 239 controls from a cross-sectional study were reexamined after a five-year period. Thereby the correlation between prevalences of respiratory symptoms and work-place concentrations of solder flux fume was confirmed. The follow-up of lung function revealed a higher influence of smoking habits compared to occupational exposures. The MBTH-method is suitable for estimation of exposure, if smoking and other aldehyde sources are excluded.

Adult↗