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Josef Rieder

Publications and source records attributed to Josef Rieder.

At least 19 recordsLinked to original sources
PubMed2006

Gender and age specific differences in exhaled isoprene levels.

The analysis of volatile organic compounds (VOC) in the human breath has attracted a considerable amount of clinical and scientific interest during the last decade. In our study, we turned our attention to gender and age specific differences of exhaled volatile compounds, particularly on isoprene which is one of the most abundant organic molecules found in human exhaled air. A total of 126 test persons were enrolled in the study: 66 females and 60 males. Moreover, the participants were classified into six groups with regard to their age. In a standardized setting all of them had to exhale the endexpiratory breath into a sample bag. The volatile compounds at m/z values from 21 to 229 were analyzed by using proton-transfer-reaction-mass-spectrometry. Isoprene (at m/z 69) was found to be highly significantly (p<0.001) elevated in the exhaled air of male subjects. Furthermore, it could be shown that 19-29 years old subjects exhale significantly lower levels of isoprene than older adults (p=0.002). No significant differences between groups were detected for any other measured mass. In conclusion, the present study demonstrates gender and age specific differences of isoprene levels in the exhaled air. These findings may be of potential clinical relevance regarding the multifaceted roles of isoprene, representing both indicator and effector molecule.

Adult↗
PubMed2005

Diagnosis of bacteria in vitro by mass spectrometric fingerprinting:a pilot study.

The identification of bacteria by using conventional microbiological techniques can be very time-consuming and circumstantial. In contrast, the headspace screening of bacterial cultures by analyzing their emitted volatile compounds using mass spectrometry might provide a novel approach in diagnostic microbiology. In the present study different strains of Escherichia coli, Klebsiella, Citrobacter, Pseudomonas aeruginosa, Staphylococcus aureus, and Helicobacter pylori were investigated. The volatile compounds emitted by these bacteria in vitro were analyzed using proton-transfer-reaction mass spectrometry, which allows rapid and sensitive measurement. The detected patterns of volatile compounds produced by the investigated bacteria were compared and substantial differences regarding both quantity and quality were observed. In conclusion, the present study is the first to describe headspace screening of bacterial cultures as a potential diagnostic approach in medical microbiology.

Bacteria↗
PubMed2005

Mass spectrometric profile of exhaled breath--field study by PTR-MS.

Recently, increased interest has focused on the diagnostic potential of volatile organic compounds (VOC) exhaled in human breath as this substance group has been conjectured in indoor air quality and disease screening. Proton transfer reaction-mass spectrometry (PTR-MS) has been established as a new tool for a rapid determination of exhaled air profile. However, no investigations have been carried out into the profile of exhaled air as determined by PTR-MS. Therefore, it was the aim of the present study to determine the profile of exhaled breath in a field survey enrolling 344 persons. Analysis was performed using PTR-MS. No significant correlations with age, blood pressure, and body mass index could be observed with any molecular mass. The present study delineates possible reference values for PTR-MS investigations into exhaled air profile. In conclusion, the present study was the first to delineate mass spectrometric characteristics of an average patient sample as possible reference values.

Aged↗
PubMed2005

Inducible nitric oxide synthase (iNOS) in tumor biology: the two sides of the same coin.

Inducible nitric oxide synthase (iNOS) is one of three key enzymes generating nitric oxide (NO) from the amino acid l-arginine. iNOS-derived NO plays an important role in numerous physiological (e.g. blood pressure regulation, wound repair and host defence mechanisms) and pathophysiological (inflammation, infection, neoplastic diseases, liver cirrhosis, diabetes) conditions. iNOS is the synthase isoform most commonly associated with malignant disease. Nevertheless, the role of iNOS during tumor development is highly complex, and incompletely understood. Both promoting and deterring actions have been described, presumably depending upon the local concentration of iNOS within the tumor microenvironment. In particular, pivotal effects such as malingnant transformation, angiogenesis, and metastasis are modulated by iNOS. On the other hand, NO derived from macrophages has a potentially cytotoxic/cytostatic effect upon tumor cells. Hence, therapeutical interference with iNOS activity is of considerable interest, especially in tumors where metastatic activity, host defence mechanisms and the level of differentiation seem to be correlated to iNOS expression. This review will aim to summarize the dual actions of iNOS as simultaneous tumor promoter and suppressor.

Gene Expression Regulation, Enzymologic↗
PubMed2005

Urinary acetonitrile concentrations correlate with recent smoking behaviour.

OBJECTIVES: To assess the concentration of acetonitrile (a saturated aliphatic nitrile) in the urine of habitual cigarette smokers and non-smokers, as exposure to smoke can be measured by monitoring ambient air or by in vivo tests, but acetonitrile measured in exhaled breath is reportedly a quantitative marker of recent smoking behaviour. SUBJECTS AND METHODS: The study included 101 volunteers (57 men and 44 women, mean age 49 years). An absence of urinary tract infection on urine analysis or clinical history was mandatory. The subjects were classified into five groups, i.e. a control group of non-smokers and four groups according to the number of cigarettes smoked daily. Urine samples were stored at 8 degrees C until acetonitrile was measured, within 24 h of collection, using proton-transfer reaction mass spectrometry (PTR-MS). Each measurement was repeated at least 10 times, and the mean used for statistical analysis. RESULTS: The mean (sd) acetonitrile level in the urine of 46 non-smokers was 3.74 (1.78) parts per billion volatile (ppbv). The concentration of acetonitrile increased with the number of cigarettes smoked daily, the highest concentration being in the subgroup of 13 very heavy smokers (>30 cigarettes/day) with means up to 28.04 (5.38) ppbv. CONCLUSION: PTR-MS is a quick, noninvasive online method for determining urinary acetonitrile levels, a marker for recent active and passive smoking behaviour, and thus for checking compliance. As smoking has been shown to affect the genesis of bladder cancer, further studies are required to determine the association of acetonitrile with bladder cancer.

Acetonitriles↗
PubMed2005

H. pylori infection increases levels of exhaled nitrate.

BACKGROUND: Helicobacter pylori infection is one of the most common chronic bacterial infections worldwide. Despite the existence of a breath test for the diagnosis of H. pylori infection, no study has described the composition of volatile compounds, especially the levels of nitrate, in the exhaled air of patients with H. pylori infection. MATERIALS AND METHODS: The volatile compounds in the exhaled air of 14 patients suffering from H. pylori gastritis and 11 controls were analyzed using proton transfer reaction-mass spectrometry. Gastric biopsy was used to establish diagnosis of current H. pylori infection. RESULTS: Comparing mass spectra between groups, Mass 28 (hydrogen cyanide, HCN) and Mass 64 (hydrogen nitrate, H2NO3) were found to be significantly elevated in patients with H. pylori infection. CONCLUSIONS: The main result of the present study is that in H. pylori-infected patients, levels of exhaled hydrogen nitrate and hydrogen cyanide are found to be significantly elevated. However, further studies are necessary to find out whether the differences in the detected mass spectrum are specific enough to differentiate patients with H. pylori gastritis from healthy controls.

Adult↗
PubMed2004

Cisatracurium, but not mivacurium, inhibits survival and axonal growth of neonatal and adult rat peripheral neurons in vitro.

Cisatracurium and mivacurium are widely used neuromuscular blocking drugs. Previous reports have indicated growth-inhibitory effects of cisatracurium, but not mivacurium, on two human cell lines in vitro. These effects were ascribed to oxidative stress elicited by acrylate esters formed during cisatracurium breakdown. The aim of the present study was to investigate whether these agents would possibly interfere with the peripheral nervous system. Survival and axonal growth of rat primary neurons obtained from the superior cervical sympathetic ganglion (SCG) or from the adult dorsal root ganglion (DRG) were investigated after treatment with cisatracurium or mivacurium at concentrations from 1 to 10 microM for 24 h. Cisatracurium, but not mivacurium, significantly decreased neuronal survival in a dose-dependent manner, and axonal length was considerably reduced by cisatracurium as compared to controls. It is concluded that high concentrations of cisatracurium are potentially neurotoxic.

Aging↗
PubMed2004

Quantification of recent smoking behaviour using proton transfer reaction-mass spectrometry (PTR-MS).

Smoking is the most important single risk factor in current public health. Surveillance of exposure to tobacco smoke may be accomplished using environmental monitoring or in-vivo tests for smoking biomarkers. Acetonitrile exhaled in human breath has been described as a potential marker mirroring recent smoking behavior. The aim of this study was to determine exhaled acetonitrile levels in a sample of 268 volunteers (48 smokers, 220 non-smokers) attending a local health fair. Breath specimens were collected into inert sample bags, with parallel collection of ambient air. Subsequently, all samples were analysed using proton transfer reaction-mass spectrometry (PTR-MS). Smokers had elevated levels of exhaled acetonitrile compared with non-smokers (p<0.001). Analysis using the receiver-operating-characteristic curve demonstrated that smoking can be predicted with a sensitivity of 79% and a specificity of 91%, using a cut-off concentration of 20.31 parts per billion of acetonitrile. This first field survey of exhaled acetonitrile in a large group of test persons demonstrates the feasibility of a rapid and non-invasive test for recent exposure to tobacco. We conclude that analysis of exhaled-breath acetonitrile may serve as a method of determining recent active smoking behaviour.

Acetonitriles↗
PubMed2004

Clear hydro-gel, compared to ointment, provides improved eye comfort after brief surgery.

PURPOSE: Anesthesia impairs lid closure and decreases tear secretion and stability. Protection may, in principle, be conveyed by manual eye closure, taping the eyelids closed, and by instillation of protective substances into the conjunctival sac. Both hydro-gels and ointments are used in clinical practice. It was the objective of the present study to compare a transparent clear ocular hydro-gel (Vidisic) and a commonly used dexpanthenol and vitamin A (Oleovit) based ointment as examples of these classes of ocular lubricants in their capability to provide perioperative eye comfort. Furthermore, their bacteriostatic properties were assessed in vitro. METHODS: Ninety-two consecutive patients undergoing total iv general anesthesia were randomly allocated to receive either ocular dexpanthenol ointment or a clear hydro-gel after induction of anesthesia. Subjects were assessed one hour following termination of anesthesia. RESULTS: Main findings were an increased incidence of foreign body sensation, adherent eyelashes and disturbance elicited by blurred vision in the ointment group as compared to clear hydro-gel (P < 0.001). Bacterial growth was significantly attenuated by the ocular hydro-gel as compared to ointment. DISCUSSION: Clear ocular hydro-gel offers improved patient comfort and decreased ocular inflammation as compared to conventional eye ointments. In addition, it decreases bacterial growth. Therefore, the use of clear ocular hydro-gel for perioperative ocular comfort is suggested.

Acrylates↗
PubMed2004

The incidence of lumbar ligamentum flavum midline gaps.

UNLABELLED: Lumbar epidural anesthesia and analgesia has gained increasing importance in perioperative pain therapy for abdominal and lower limb surgery. The loss-of-resistance technique, used to identify the epidural space, is thought to rely on the penetration of the ligamentum flavum. However, the exact morphology of the ligamentum flavum at different vertebral levels remains controversial. Therefore, in this study, we directly investigated the incidence of lumbar ligamentum flavum midline gaps in embalmed cadavers. Vertebral column specimens were obtained from 45 human cadavers. On each dissected level, ligamentum flavum midline gaps were recorded. The incidence of midline gaps per number of viable specimens at the following levels was: L1-2 = 10 of 45 (22.2%), L2-3 = 5 of 44 (11.4%), L3-4 = 5 of 45 (11.1%), L4-5 = 4 of 43 (9.3%), L5/S1 = 0 of 33 (0%). In conclusion, the present study determined the frequency of lumbar ligamentum flavum midline gaps. Gaps in the lumbar ligamentum flavum are most frequent between L1 and L2 but are more rare below this level. When using the midline approach, the ligamentum flavum may not impede entering the epidural space in all patients. IMPLICATIONS: The ligamentum flavum is a crucial anatomical landmark for the safe performance of epidural anesthesia. However, the present study demonstrates some failure of the lumbar ligamentum flavum as a landmark. This may mean that, using a midline approach, one cannot always rely on the ligamentum flavum as a perceptible barrier to epidural needle advancement.

Cadaver↗
PubMed2003

Neopterin as a potential modulator of tumor cell growth and proliferation.

The present article proposes tumor-promoting biochemical effects of the immunologically active pteridine-compound neopterin. Based on previous findings of interactions between neopterin and the cellular redox state, two major pathways of tumor progression are presented: (1) the inhibition of nitric oxide-induced apoptotic death of tumor cells via suppression of nitric oxide synthesis in the presence of neopterin; (2) the stimulatory effects of neopterin on the production and release of angiogenic growth factors. High serum neopterin concentrations are a common finding in tumor patients and correlate well with the fatal outcome of the disease. Affection of tumor tissue growth as well as formation of metastases by neopterin may provide an explanation for these clinical observations.

Apoptosis↗
PubMed2003

Anaesthetic implications of Robinow syndrome.

Robinow (fetal face) syndrome is a rare inherited multisystem disorder featuring mesomelic or acromesomelic limb shortening, facial and spinal deformities, hypoplastic genitalia, kidney disease and congenital heart defects. We report the anaesthetic management of a patient with Robinow syndrome presenting for elective surgery and review specific issues of interest in the perioperative workup.

Abnormalities, Multiple↗
PubMed2003

Elective haemodialysis increases exhaled isoprene.

BACKGROUND: Uraemic odour is a characteristic feature of patients with end-stage renal disease (ESRD). However, few investigations have been carried out into the composition of exhaled air in ESRD patients undergoing haemodialysis (HD). Increases of exhaled isoprene levels by a factor of up to 2.7 following HD have been reported. METHODS: We attempted to confirm these findings in 50 patients undergoing HD using haemophan (n=23) or polysulphone (n=27) dialysis membranes. Parallel evaluation of ambient air, calorie intake, medication and haemodynamic variables was performed. Samples were analysed using proton transfer reaction-mass spectrometry (PTR-MS). RESULTS: Significant changes in breath isoprene concentration were observed when comparing patients before [39.14+/-14.96 parts per billion (ppbv)] and after (63.54+/-27.59 ppbv) dialysis (P<0.001). The quotient of values before and after dialysis was 1.84 (SD 1.41). No significant differences in isoprene kinetics were found between the use of haemophan and polysulphone membranes. No significant correlations were observed between isoprene quotients and variations in blood pressure during HD, calorie intake, ingestion of lipid-lowering drugs or serum lipid levels. CONCLUSIONS: Isoprene concentration was higher in the exhaled air of patients after HD as compared with values before HD. Large interindividual variability existed in isoprene kinetics. Oxidative stress appears to be an unlikely cause for this rise. An alternative hypothesis is an influence of respiratory variables on isoprene exhalation based upon Henry's law constant. We therefore propose to perform online monitoring of isoprene exhalation by PTR-MS during the HD session to investigate the possible influence of respiratory variables.

Adult↗