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Biomedical subjects

K Ritter

Publications and source records attributed to K Ritter.

At least 19 recordsLinked to original sources
PubMed2005

Autoantibodies to human manganese superoxide dismutase (MnSOD) in children with facial palsy due to neuroborreliosis.

AIM: Acute peripheral facial palsy due to neuroborreliosis is associated with a distal neuritis. In patients with Lyme disease the activity of antioxidant enzymes is decreased. With respect to the pathogenesis of neuroborreliosis, sera of children with acute peripheral facial palsy were investigated for autoantibodies against human manganese superoxide dismutase (MnSOD), which were suspected of raising the oxidative injury of infected tissues. METHODS: Sera of 20 children with acute peripheral palsy with neuroborreliosis, sera of 20 children with facial palsy without reference to Lyme disease and sera of 14 blood donors were tested for antibodies against human MnSOD using an ELISA. RESULTS: The concentrations of IgM autoantibodies to MnSOD of the children with neuroborreliosis were significantly increased, compared with the two control groups. CONCLUSIONS: We propose that the antibodies detected block the protective effects of MnSOD resulting in an increased oxidative inflammation.

Autoantibodies↗
PubMed2004

Comparison of bacterial indicator analysis methods in stormwater-affected coastal waters.

Membrane filtration (MF) and multiple tube fermentation (MTF) have been used for decades to measure indicator bacteria levels in beach water samples, but new methods based on chromogenic substrate (CS) technology are becoming increasingly popular. Only a few studies have compared results among these methods and they have generally been based on samples collected from a limited number of sites during dry weather. In this study, samples were collected from 108 sites the day after a major rainstorm, and three indicator bacteria (total coliforms (TCs), fecal coliforms (FCs) or E. coli, and enterococci (EC)) were each measured using MF, MTF, and CS. Sampling sites were selected using a stratified random design, stratified by open sandy beach, rocky shoreline, and beach areas near urban runoff outlets. The CS results were found to be highly correlated with both MF and MTF for all three indicators regardless of whether the samples were taken along open shoreline or near a runoff outlet. While correlated, TC values were higher using the CS method, consistent with other studies that have demonstrated false positives with this method. FC values were 12% lower with CS, reflecting the specificity of the CS method for E. coli rather than for the entire FC group. No significant differences were observed for EC, although some differences were observed within specific laboratories. Differences for all of these indicators were small enough that, when assessed categorically, there was more than 90% agreement between CS methods and either MF or MTF methods as to whether State of California Beach Water Quality Standards were met or exceeded.

California↗
PubMed2003

An in situ study of the effect of nitrate on the reduction of trichloroethylene by granular iron.

The effect of nitrate on the reduction of TCE by commercial granular iron was investigated in column experiments designed to allow for the in situ monitoring of the iron surface film with Raman spectroscopy. Three column experiments were conducted; one with an influent solution of 100 mg/l nitrate+1.5 mg/l TCE, and two control columns, one saturated directly with 100 mg/l nitrate solution, the other pre-treated with Millipore water prior to the introduction of a 100 mg/l nitrate solution. In the presence of nitrate, TCE adsorbed onto the iron, but there was little TCE reduction to end-products ethene and ethane. The iron used (Connelly, GPM, Chicago) is a product typical of those used in permeable granular iron walls. The material is covered by an air-formed high-temperature oxidation film, consisting of an inner layer of Fe(3)O(4), and an outer, passive layer of Fe(2)O(3). In the control column pre-treated with Millipore water, the passive Fe(2)O(3) layer was removed upon contact with the water in a manner consistent with an autoreduction reaction. In the TCE+nitrate column and the direct nitrate saturation column, nitrate interfered with the removal of the passive layer and maintained conditions such that high valency protective corrosion species, including Fe(2)O(3) and FeOOH, were stable at the iron surface. The lack of TCE reduction is explained by the presence of these species, as they inhibit both mechanisms proposed for TCE reduction by iron, including catalytic hydrogenation, and direct electron transfer.

Iron↗
PubMed2002

Homocysteine and risk of open-angle glaucoma.

Homocysteine levels and the frequency of heterozygous methylenetetrahydrofolate reductase (MTHFR) C677T mutation are increased in open-angle glaucoma. Since homocysteine can induce vascular injury, alterations in extracellular matrix remodelling, and neuronal cell death, these findings may have important implications for understanding glaucomatous optic neuropathy.

Adult↗
PubMed2002

Jailhouse Blues revisited.

BACKGROUND: Over the past decades a number of studies have appeared on suicide among persons in jail and prison remand settings, and sentenced prisoners. In these papers contradictory views concerning the relation between suicide risk and length of custody were published. METHODS: This article reports on a study that investigated all suicides (n=206) in all 29 Austrian jails and prisons between 1975 and 1996. The authors demonstrate the necessity to calculate the hazard that reflects the suicide risk in relation to time. RESULTS: The results suggest three different periods of high suicide risk: immediately after admission and 2 months thereafter for prisoners on remand; for long-term prisoners the suicide risk correlates with the length of the sentence and slightly increases with the time of custody. CONCLUSIONS: With this knowledge, suicide prevention programmes in prisons and jails could be made more effective and economic.

Austria↗
PubMed2002

An in situ study of the role of surface films on granular iron in the permeable iron wall technology.

Permeable walls of granular iron are a new technology developed for the treatment of groundwater contaminated with dissolved chlorinated solvents. Degradation ofthe chlorinated solvents involves a charge transfer process in which they are reductively dechlorinated, and the iron is oxidized. The iron used in the walls is an impure commercial material that is covered with a passive layer of Fe2O3, formed as a result of a high-temperature oxidation process used in the production of iron. Understanding the behaviour of this layer upon contact with solution is important, because Fe2O3 inhibits mechanisms involved in contaminant reduction, including electron transfer and catalytic hydrogenation. Using a glass column specially designed to allow for in situ Raman spectroscopic and open circuit potential measurements, the passive layer of Fe2O3 was observed to be largely removed from the commercial product, Connelly iron, upon contact with Millipore water and with a solution of Millipore water containing 1.5 mg/l trichloroethylene (TCE). It has been previously shown that Fe2O3 is removed from iron surfaces upon contact with solution by an autoreduction reaction; however, prior to this work, the reaction has not been shown to occur on the impure commercial iron products used in permeable granular iron walls. The rate of removal was sufficiently rapid such that the initial presence of Fe2O3 at the iron surface would have no consequence with respect to the performance of an in situ wall. Subsequent to the removal of Fe2O3 layer, magnetite and green rust formed at the iron surface as a result of corrosion in both the Millipore water and the solution containing TCE. The formation of these two species, rather than higher valency iron oxides and oxyhydroxides, is significant for the technology. The former can interfere with contaminant degradation because they inhibit electron transfer and catalytic hydrogenation. Magnetite and green rust, in contrast, will not inhibit the mechanisms involved in contaminant reduction, and hence their formation is beneficial to the long-term performance of the iron material.

Catalysis↗
PubMed2001

Cloning and expression of the human single copy homologue of the mouse zinc finger protein zfr.

A human homologue of the murine zinc finger protein zfr is transcriptionally induced in the Epstein-Barr virus-positive Burkitt lymphoma cell line Raji upon treatment with the granulocyte/macrophage lineage ganglioside IV(3)NeuAc-nLcOse(4)Cer. The gene was cloned by a rapid amplification of cDNA ends approach based on a cDNA clone. The resulting hzfr sequence is 3393 base pairs in length coding for a protein of 1057 amino acids. Sequence alignments between hzfr and zfr reveal an identity of 92% on the nucleotide level and an identity of 96.4% on the amino acid level, respectively. Based on Southern blot data hzfr can be addressed as a single copy gene. Tissue-specific expression was determined by semi-quantitative PCR of normalized cDNA populations from various human tissues with glyceraldehyde-3-phosphate dehydrogenase as an internal control. Highest levels of transcripts were found in brain. hzfr transcripts could not be detected in skeletal muscle.

Amino Acid Sequence↗
PubMed2001

[Deprivation versus importation: a model explaining the increase of suicide rates in custody].

High suicide rates in jail, lock-up or prison settings have given rise to a debate about whether suicides result chiefly from the type of people confined, or from the types of places they are confined in, the types of confinement. This is summarily framed by the terms of an associated debate in criminology, between importation and deprivation theory. This paper describes the importation versus deprivation theory, concerning the circumstances in Austrian prisons and jails. The article reports on all completed suicides over the period from 1947 to 1999 (n = 410). The increase of suicide rates in Austrian jails and prisons is significant over the last fifty years. While the rate was stable between 1947 and 1975, we have a significantly increasing rate since 1975. In 1975 there was an important legislational reform of the criminal law in Austria. The implications of this reform are discussed in the light of the importation/deprivation theory.

Adult↗
PubMed2001

[Early rehabilitation in Baden-Wurttemberg--a study of all Baden-Wurrtemberg early rehabilitation centers].

Over a period of 12 months, all persons among the 10.4 million inhabitants of the state of Baden-Württemberg were included in the study who had suffered severe brain damage and were treated in special early rehab units, comprising 147 beds for adults and 43 for children. With 830 patients admitted, the incidence of severe brain damage was 7.98/100.000 in adults and 1.11/100.000 in children. 50 to 70 year old patients were over-represented, those older than 70 years were underrepresented due to geriatric rehab facilities for the latter. Male patients dominated, while female were somewhat younger. 54% of the patients were admitted from the hospital which had performed primary care, with an average stay of 67 days. Average early rehab duration was 53 days (arithmetic average; median 40 days, some patients required up to one year). 32.8% of the patients had suffered traumatic brain damage (ICD 851, 852, 854) and 40.9% non-traumatic brain affection (ICD 430, 431, 433-438, 310, 348), including 12.2% CVA (ICD 433-438), 8.5% subarachnoid and 12.3% intracerebral hemorrhage. Severity as indexed by the early rehab Barthel index improved from an initial average of -119 to -34 at discharge. 80% of the patients showed an overall improvement (71% of them by up to 200 points and 46% by up to 100 points).

Adolescent↗
PubMed2001

[Did suicidal behavior have relevance for prison suicide?].

OBJECTIVE: Suicides in correctional institutions occur more frequently than in the general population. Inmate suicide rates have been increasing in many countries during the last decades, possibly reflecting a selection of highly endangered individuals with a high prevalence of mental disorders. This study investigates all suicides in all correctional institutions of Austria during the last 25 years. METHODS: All available personal files of inmates who had committed suicide in the 29 Austrian prisons between January 1st, 1975, and December 31st, 1999, were analysed. Beside personal characteristics and circumstances of custody, information concerning psychiatric disorders and the inmate's history of suicidal behavior was included. RESULTS: 220 personal files of 250 suicides were available and included. Half of all suicides had a history of attempted suicide and 37 % had expressed suicidality. Referral to psychiatric consultants was known in 48.6 % and about 37 % received psychopharmacological treatment. Based on these frequent signs of psychiatric illness and vulnerability, possible implications of these results for psychiatric services of the correctional system to improve suicide prevention are discussed. CONCLUSIONS: Obvious signs of suicidality play an important role in vulnerability profiles for jail and prison suicides. Any signs of suicidality (st. p. attempted suicide, verbal suicide threat, self-harm) should have the consequence of further psychiatric care.

Adult↗
PubMed2000

Early steps in termination of the immortalization state in Burkitt lymphoma: induction of genes involved in signal transduction, transcription, and trafficking by the ganglioside IV(3)NeuAc-nLcOse(4)Cer.

Stimulation by the ganglioside IV(3)NeuAc-nLcOse(4)Cer leads to growth arrest in the Burkitt lymphoma cell line Raji. In order to analyze the primary response of Raji cells to that stimulus, a cDNA array screen and a suppression subtractive hybridization-PCR approach were performed. Twenty-four genes with assigned functions were confirmed to be induced by the ganglioside in reverse Northern blot experiments covering e.g. protein kinase B, phospholipase C, the MAP-kinase ERK3, the transcription factors YY1, DR1 and NSEP, the membrane traffic protein TAP, and the nuclear export protein CRM1. Most of the genes identified are involved in signal transduction, transcription, and cell trafficking. For selected genes, the induction of expression was quantified by semiquantitative RT-PCR.

Burkitt Lymphoma↗
PubMed2000

Enhanced transcription of the s-adenosylhomocysteine hydrolase gene precedes Epstein-Barr virus lytic gene activation in ganglioside-stimulated lymphoma cells.

Stimulation of Epstein-Barr virus (EBV) genome-positive Burkitt lymphoma cells with the ganglioside IV3NeuAc-nLcOse4Cer leads to the induction of cell differentiation processes and activates the EBV lytic viral cycle. In cells of the Burkitt lymphoma line Raji differential expression of host cell genes was analysed in the early phase (150 min) post stimulation with the ganglioside to display the cell activities that precede the activation of the EBV lytic cycle using the differential display reverse transcription-polymerase chain reaction technique. Multiple fragment cDNAs derived from control cells and ganglioside-stimulated cells were amplified using random primers and displayed via polyacrylamide gel electrophoresis. The expression pattern of 8,400 bands was analysed. Eleven differentially expressed fragment cDNAs were reamplified and identified by nucleotide sequencing. Six of these could be identified as coding for proteins that may take part in virus reactivation and differentiation. The most striking finding was the induction of s-adenosylhomocysteine hydrolase (AHCY) expression. The cellular enzyme AHCY plays an important role in transmethylation reactions controlling the replication of several viruses. Thus. an involvement in EBV replication can be suggested.

Adenosylhomocysteinase↗
PubMed2000

Induction of growth rate and transcriptional modulation of growth promoters and growth inhibitors in epithelial cells by EBV-LMP1.

LMP1 is a genuine oncogene encoded by the Epstein-Barr virus (EBV). The cellular response to expression of the EBV-encoded gene LMP1 in the epithelial cell line Wish was studied. Cells were stably transfected with pCEP-LMP, an expression vector for LMP1. On transcript level a transient expression of the LMP1-gene with a maximum 2 days post transfection was observed. Six days post transfection the rate of DNA synthesis of LMP1-transfected Wish cells was increased by 80% compared to control cells, after 2 further days the number of cells was increased by 32%. A human cDNA-array was screened with probes from LMP1-transfected and control cells showing induction of transcription for proliferation associated genes and repression for growth suppressor genes.

Cell Division↗
PubMed2000

Detection of cytomegalovirus DNA in human specimens by LightCycler PCR.

Detection of human cytomegalovirus (CMV) DNA in clinical specimens is considered a cornerstone in the diagnosis of CMV disease. The aim of this study was to evaluate a newly designed LightCycler-based quantitative CMV PCR. Specimens of human origin (n = 200) were tested using the LightCycler PCR, the quantitative COBAS AMPLICOR CMV MONITOR (CACM) assay, and a qualitative in-house PCR assay for the presence of CMV DNA. Samples that were reactive in at least two of the three assays were considered CMV DNA positive (n = 95 [47. 5%]), while samples that were nonreactive in two of the three assays were considered CMV DNA negative (n = 105 [52.5%]). Using the LightCycler assay, CMV DNA was detected in 91 of the 95 CMV DNA-positive human specimens (sensitivity, 95.8%; 95% confidence interval [CI], 89.6 to 98.8) and in 1 of the CMV DNA-negative specimens (specificity, 99%; 95% CI, 94.8 to 99.8). Results of CMV load determination as assessed by both quantitative test systems were correlated (r = 0.73; P < 0.0001; 95% CI, 0.61 to 0.81). Results for undiluted samples containing a high CMV load were more accurate with the LightCycler test than were results obtained with the CACM test, which underestimated the viral load of samples containing high DNA copy numbers. The high level of sensitivity, specificity, accuracy, and rapidity provided by the LightCycler technology are favorable for the use of this system in the detection of CMV DNA in clinical specimens.

Cytomegalovirus↗
PubMed2000

Placebo-controlled sleep laboratory studies on the acute effects of zolpidem on objective and subjective sleep and awakening quality in nonorganic insomnia related to neurotic and stress-related disorder.

UNLABELLED: Recent investigations in our sleep outpatient clinic demonstrated that 30% of patients exhibited organic and 70% nonorganic sleep disorders, with 41% showing as an additional diagnosis neurotic, stress-related, and somatoform disorders, 31% affective disorders and 15% mental and behavioral disorders due to psychoactive substance use. Thus, the aim of the study was to investigate the acute effects of the imidazopyridine zolpidem on objective and subjective sleep and awakening quality in the largest of the above-mentioned groups. In this single-blind, placebo-controlled cross-over study, 15 patients (9 females and 6 males aged 51.1 + 11. 3 years) diagnosed as having nonorganic insomnia (ICD-10: F 51.0) related to neurotic and stress-related disorders (F 1.1:12, F 41.2:2 and F 43.2:1) were included. Objective and subjective sleep and awakening quality measures were investigated in 3 subsequent nights in the sleep laboratory (adaptation, baseline/placebo and zolpidem 10 mg night), utilizing clinical, polysomnographic, psychometric and psychophysiological methods. The drug-free patients were matched according to age and sex with 15 normal healthy controls (age 51.2 + 11.8 years). Statistical analysis of polysomnographic variables demonstrated a significant lengthening of the total sleep period (TSP) and total sleep time (TST), an improvement in sleep efficiency and a shortening of sleep latencies after zolpidem as compared with placebo. These changes were opposite to the differences between patients and controls. Concerning sleep architecture, zolpidem increased the length of S4 and S3 + S4 as compared with placebo. Subjective sleep and awakening quality and the thymopsychic variables drive, mood, affectivity and wakefulness in the morning showed no significant changes, as a significant improvement had already occurred from the adaptation to the baseline/placebo night. Noopsychic variables (attention, concentration, attention variability, numerical memory, fine motor activity, reaction time measures) showed similar findings. Moreover, subjective sleep and awakening quality, thymopsychic and noopsychic measures during baseline/placebo recordings did not differ significantly from normative data (except for fine motor activity). Psychophysiological measures did not show any significant alterations either, except for a decrease in systolic blood pressure in the evening. CONCLUSION: As compared with placebo, zolpidem induced a significant improvement in objective sleep quality, mainly by increasing TSP, TST and sleep efficiency and shortening sleep latencies, thereby normalizing the disorder of initiating and maintaining sleep. Deep sleep stages S3 + S4 increased (although at baseline/placebo these stages did not differ from controls), while S1, S2 and SREM did not change significantly. Subjective sleep and awakening quality as well as thymopsychic and noopsychic performance in the morning mainly showed a placebo and 'first- night effect' phenomenon in these patients. Thus, the changes induced by zolpidem were somewhat different from those after classical benzodiazepines.

Cross-Over Studies↗
PubMed2000

Sleep laboratory studies in restless legs syndrome patients as compared with normals and acute effects of ropinirole. 1. Findings on objective and subjective sleep and awakening quality.

Although the restless legs syndrome (RLS) is a disorder with a relatively high prevalence rate (8% in Austria) and leads to insomnia and excessive daytime tiredness, there is a paucity of sleep laboratory data concerning objective and subjective sleep and awakening quality. Thus, the aim of this study was to investigate 12 untreated RLS patients as compared with 12 normal controls and subsequently measure the acute effects of 0.5 mg ropinirole (Requip((R))) - a nonergoline dopamine agonist - as compared with placebo. In 3 nights (adaptation, placebo, ropinirole night) sleep induction, maintenance and architecture were measured objectively by polysomnography, subjective sleep and awakening quality were assessed by self-rating scales and visual-analog scales, and objective awakening quality was evaluated by a psychometric test battery. In polysomnography, RLS patients demonstrated, as compared with normal controls, a decreased total sleep time (TST) and sleep efficacy, increased wakefulness during the total sleep period and frequency of nocturnal awakenings, increased sleep stage S1, decreased S2 and increased stage shifts. Subjective sleep quality tended to decrease, and morning well-being, mood, affectivity and wakefulness were deteriorated. In the noopsyche, fine motor activity and reaction time performance were deteriorated. Ropinirole 0.5 mg induced, as compared with placebo, an increase in TST, sleep efficacy, S2 sleep and stage shifts. In the morning, somatic complaints increased slightly, while fine motor activity and reaction time performance improved. Our findings suggest a key-lock principle in the diagnosis/treatment of RLS and a dopaminergic mechanism in its pathogenesis, which is supported by the data on periodic leg movements during sleep and arousals of the subsequent paper.

Administration, Oral↗