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R Seidl

Publications and source records attributed to R Seidl.

At least 19 recordsLinked to original sources
PubMed1997

Evidence against increased oxidative DNA-damage in Down syndrome.

In Down syndrome (DS), oxidative DNA-damage may play a role in the pathogenesis of characteristic mental retardation and precocious dementia of Alzheimer type. We measured the oxidized nucleoside, 8-hydroxy-2'-deoxyguanosine (8-OHdG), in nuclear DNA (nDNA) isolated from four different regions of cerebral cortex and cerebellum in 10 adult DS and 10 Alzheimer's disease (AD) patients compared to normal controls. Levels of 8-OHdG in post-mortem brain tissue were investigated by means of high-performance liquid chromatography with electrochemical detection. There was no significant increase in DS and AD compared to controls in any of the brain regions. Highest amounts of 8-OHdG were in temporal cortex in DS (180.0 +/- 9.6 nmol/g wet weight tissue), AD (172.4 +/- 14.6 nmol/g wet weight tissue) and controls (183.4 +/- 12.7 nmol/g). We conclude that the results provide evidence against an increased reactive oxygen species (ROS) induced damage to nDNA in DS and AD.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1997

Evidence against increased glycoxidation in patients with Alzheimer's disease.

Neuropathological findings of Alzheimer's disease (AD) are intracellular (neurofibrillary tangles) and extracellular (senile plaques) filamentous protein aggregates. Non-enzymatic glycation has been proposed as a primary factor in this pathogenesis, leading to increased insolubility of tau protein and beta-amyloid. The aim of our study was to test the hypothesis that increased glycoxidation, i.e. increased levels of oxidized products from non-enzymatic glycation could be found in brains of patients with AD and of aged Down syndrome (DS) subjects with abundant AD-like neuropathological lesions. Frontal cortex specimens were assayed for pentosidine (Pent) and N-epsilon-carboxymethyl-lysine (CML) by reversed phase high performance liquid chromatographical methods. Pent and CML levels in AD (n = 10; Pent, 35.5 +/- 4.84 mumol/g wet-weight tissue; CML, 135.2 +/- 5.0 mumol/g wet-weight tissue) were comparable to DS (n = 9; Pent, 36.4 +/- 3.21; CML, 133.5 +/- 4.7) and controls (n = 10; Pent, 35.2 +/- 3.55; CML, 136.9 +/- 3.3). We conclude that the results are not compatible with the concept of increased glycoxidation in AD compared to normal aging.

Aged↗
PubMed1997

Auditory evoked potentials in young patients with Down syndrome. Event-related potentials (P3) and histaminergic system.

Subjects with Down syndrome exhibit various types of cognitive impairment. Besides abnormalities in a number of neurotransmitter systems (e.g. cholinergic), histaminergic deficits have recently been identified. Brainstem auditory evoked potentials (BAEPs) and auditory event-related potentials (ERPs), were recorded from 10 children (aged 11-20 years) with Down syndrome and from 10 age- and sex-matched healthy control subjects. In Down subjects, BAEPs revealed shortened latencies for peaks III and V with shortened interpeak latencies I-III and I-V. ERPs showed a delay of components N1, P2, N2 and P3. In addition, subjects with Down syndrome failed to show P3 amplitude reduction during repeated stimulation. To evaluate the cognitive effects of histaminergic dysfunction, ERPs were recorded from 12 healthy adults (aged 20-28 years) before and after antihistaminergic intervention (pheniramine) compared to placebo. Whereas components N1, P2, N2 remained unchanged after H1-receptor antagonism, P3 latency increased and P3 amplitude showed no habituation in response to repeated stimulation. The results suggest that the characteristic neurofunctional abnormalities present in children with Down syndrome must be the consequence of a combination of structural and neurochemical aberrations. The second finding was that antihistaminergic treatment affects information processing tested by ERPs similar to that seen with anticholinergic treatment.

Adolescent↗
PubMed1997

The effect of behavioural states on cerebral oxygenation during endotracheal suctioning of preterm babies.

Near infrared spectroscopy (NIRS) was used to investigate the effect of behavioural states on changes of oxygenated (O2Hb), deoxygenated haemoglobin (HHb) and total haemoglobin (tHb), during endotracheal suctioning. In an open prospective design, NIRS measurements have been done during 20 suctioning episodes in 13 preterm neonates. Heart rate, arterial oxygen saturation, and carbon dioxide tension were monitored continuously. Behavioural state (BS) observations were made and documented as well. The statistical analysis showed that in patients who were active, with crying periods during suctioning (behavioural states 4-5), changes of oxygenated (p < 0.005) and deoxygenated haemoglobin (p < 0.05), as well as of arterial oxygen saturation (p < 0.05) and heart rate (p < 0.05) were significantly greater than in patients who were quiet with predominant behavioural state 1, 2 and 3. These results underline the influence of behavioural states on the physiological answers to endotracheal suctioning. NIRS proved to be a valuable tool to evaluate possible harmful effects of different suctioning techniques.

Cerebrovascular Circulation↗
PubMed1996

Polyamines in frontal cortex of patients with Down syndrome and Alzheimer disease.

Polyamines may play an important role in brain development, mature brain function and also in neurodegenerative conditions. We investigated polyamine levels in frontal cortex of human post-mortem brain samples of elderly patients with Down syndrome (DS), Alzheimer disease (AD) and normal controls by means of chromatographic separation after dansylation. Spermidine and spermine concentrations were markedly decreased in DS and AD. Polyamine levels were neither related to age and post-mortem interval nor to choline acetyltransferase activity, as indicator of neuronal loss. Our results support the idea that besides other neurotransmitter systems, endogenous polyamine levels are altered in dementing illnesses such as Alzheimer disease and Down syndrome.

Aged↗
PubMed1996

Endogenous opioids in frontal cortex of patients with Down syndrome.

The main purpose of this study was to investigate differences regarding endogenous opioids in post-mortem frontal cortex of adult patients with Down syndrome (DS), patients with Alzheimer disease (AD) and neurologically healthy persons, respectively, using specific radioimmunoassays. The results of this study show that there is an increase in the levels of leu-enkephalin and dynorphin A in the frontal cortex of patients with DS as compared to the control group. An almost identical increase was also observed when comparing patients with AD to controls. In conclusion, the results of this study suggest a relationship between elevated tissue levels of leuenkephalin and dynorphin A in cerebral cortex and cognitive impairments in patients with DS and AD.

Aged↗
PubMed1996

Prognosis of childhood epilepsy in newly referred patients.

The aim of this study was to investigate the prognosis of childhood epilepsy and to analyze prognostic factors in addition to remission rate in a follow-up of newly referred patients. Two hundred eighty-one patients were followed for a mean period of 5.3 years. Overall, 253 patients (90%) achieved 1-year remission. The beginning of a 1-year seizure-free period was achieved in 77.9% by 1 year, in 84% by 2 years and in 88.6% by 3 years after onset of treatment. Early onset of seizures, symptomatic etiology, and neurologic handicap predicted a worse prognosis. In 44 of 253 children with complete suppression of seizures for 1 year, relapses occurred within the follow-up period. In one child with a relapse, remission could not be achieved in the 2nd year thereafter. In conclusion, our study shows a good prognosis for most children with epilepsy, especially in patients with idiopathic epilepsy and late onset of seizures and without neurologic dysfunction. Moreover, our data strongly suggest that the long-term pattern of seizure control is largely established during the first 2 years of treatment.

Adolescent↗
PubMed1996

Brainstem auditory evoked potentials and visually evoked potentials in young patients with IDDM.

OBJECTIVE: To investigate whether young IDDM patients develop central nervous dysfunction and to establish a possible relationship with various disease parameters. RESEARCH DESIGN AND METHODS: Thirty-two patients, aged 13.5 +/- 2 years, with disease duration of 6 +/- 2.6 years and age of onset of 7.7 +/- 3.2 years (group 1), and 21 patients with short-term disease, age 9.7 +/- 3.5 years, duration of disease < 2 years and age of onset of 9.4 +/- 3.3 years (group 2) were compared with age- and sex-matched control subjects. Exclusion criteria were clinical signs of neuropathy, retinopathy, nephropathy, or hearing impairment. Neurophysiological studies included auditory and visually evoked potentials (EPs). RESULTS: Patients in group 1 revealed increased P100 latencies of visually EPs (103.4 +/- 4.5 vs. 96.8 +/- 3.7 ms) and interpeak latencies I-V of auditory EPs (4.16 +/- 0.10 vs. 3.99 +/- 0.09 ms) and had abnormal latencies (values outside 2.5 SD) in 37%. However, short-term patients (group 2) had results within normal limits compared with control subjects. In group 1, longer disease duration and younger age at onset correlated with an increase of P100 latency (P < 0.001) and IPL I-V (P < 0.001). Patients with a history of severe hypoglycemic episodes had increased latencies compared with patients without hypoglycemia (P < 0.05). Furthermore, metabolic control during the last 2 years was related to P100 latencies (P < 0.05). CONCLUSIONS: EPs noninvasively detect subclinical central nervous system involvement in children and adolescents with IDDM. Most important risk factors are duration of disease and frequency of severe hypoglycemia.

Acoustic Stimulation↗
PubMed1995

Quantitative EEG in young diabetics.

The aim of this study was to investigate the influence of metabolic control on quantitative electroencephalographic (EEG) abnormalities in young diabetic patients. We compared quantitative EEGs of 44 insulin-dependent diabetic patients with age-matched controls. Furthermore, differences in EEG variables of diabetic patients and controls were correlated with the age of onset and duration of diabetes, hemoglobin A1c concentrations, and episodes with severe hypoglycemia. We found a correlation between high values of hemoglobin A1c and decreased relative power of the alpha band. Patients with previous ketoacidotic episodes had increased relative power of the delta/theta band and decreased relative power of the alpha band. Patients with hemoglobin A1c values less than 8.5% exhibited slowing of background activity compared with normal controls. We conclude that metabolic control influences the EEG and that improvement of glucose metabolism is an important factor in avoiding EEG abnormalities in young diabetic patients.

Adolescent↗
PubMed1994

Continuity and discontinuity of psychopathology: a study of patients examined as children and as adults. III--The infancy of "adult personality disorders".

We undertook a prospective study of all the children who, having consulted the Child Psychiatry Services (Service Médico-Pédagogique) between 1963 and 1967, later consulted the Adult Public Psychiatry Service (720 cases). We looked for specific clinical clusters which would enable us to differentiate statistically the groups of children according to their adult diagnoses. We present here the results for the group of children who were diagnosed as suffering from "personality disorders" in adulthood. We were able to establish an infantile cluster that significantly differentiated these children. It includes: aggressiveness, oppositional behaviour, unsociability, conflicts with peers. 54.6% had already been diagnosed as suffering from personality disorders in childhood. According to these results, the more a consulting child fits this profile, the greater the risk that he will suffer from a "personality disorder" in adulthood. We discuss the continuity/discontinuity of the symptomatology, and the implications for diagnoses of "personality disorders" and "borderline personalities".

Adolescent↗
PubMed1993

Quantitative EEG before and after open heart surgery in children. A significant decrease in the beta and alpha 2 bands postoperatively.

Quantitative EEGs of 30 patients undergoing open heart surgery were investigated before, 6 days, 11 days and 44 days after operation. The study was conducted in order to investigate whether quantitative EEGs can show postoperative changes in children after open heart surgery. In 28 children, no new neurological signs of cerebral involvement were seen postoperatively. The most striking feature in these children was a significant decrease in the beta and the alpha 2 bands 6 and 11 days postoperatively. The pattern in the delta band was dominated by an increase 6 days postoperatively. Except for a slight decrease in alpha 2 waves, all variables were restored to preoperative values at 44 days after the operation. We found a significant decrease in plasma sodium and chloride after surgery but children with no or slight declines (1-3 mmol/l) also showed increased slow activity postoperatively. Therefore we conclude that an organic brain syndrome, although usually mild and transient, is a general phenomenon after open heart surgery.

Adolescent↗
PubMed1993

[Continuity and discontinuity of psychopathology: a study of patients examined as children and as adults. II. Childhood antecedents of drug dependent adults].

The demographic stability of the Swiss Canton of Geneva provided us with the necessary conditions for a follow-up study of the entire childhood population who, having consulted the Child Psychiatry Services between 1963 and 1967, later consulted the adult public psychiatric services (720 cases). We looked for specific clusters of clinical signs which would enable us to differentiate, statistically speaking, the groups of children according to their adult diagnosis. We present here the results for the group of children who were diagnosed at adulthood as drug addicts (DSM III R). We found a specific cluster significantly differentiating these children from the other populations. It includes: a personality disorder (undifferentiated behaviour, and solitary and aggressive behaviour), environmental factors (monoparental, rejecting family) and a lack of mental deficiency.

Adolescent↗
PubMed1992

[Continuity and discontinuity of psychopathology: a study of patients examined as children and as adults. I. Antecedents of adult schizophrenic disorders].

The demographical stability of the Canton of Geneva made it possible for us to do a prospective study of all the children who had consulted the Child Psychiatry Service between 1963 and 1967 and who later consulted the public adult psychiatry services. On the basis of the adult diagnoses, wo looked for specific clinical "clusters" in childhood which would allow us to differentiate statistically the groups of children. We present here the results of the group of children who developed schizophrenia in adulthood. We found a specific childhood "cluster" which clearly distinguishes these children from the others. It includes: serious relational disorders, neurodevelopmental impairment, attention deficit and school learning disorders.

Adolescent↗
PubMed1991

Preparative purification of dipeptidyl peptidase IV.

Dipeptidyl-Peptidase IV was purified from pig kidney by ammonium sulfate fractionation, gel filtration, QAE-cellulose chromatography and affinity columns with Gly-Pro- and Concanavalin A-Sepharose. The specific activity of the purified enzyme is 41.8 units/mg. Polyacrylamide gel electrophoresis and silver staining show a single band. The enzyme preparation is free of aminopeptidase and dipeptidase activity, proved fluorimetrically and by gas chromatography/mass spectrometry. The most important procedure for removal of contaminating enzyme activities is a stepwise NaCl-gradient on a QAE-ZetaPrep ion exchange disk.

Animals↗
PubMed1975

[The diagnosis of gall-stones by ultrasonics (author's transl)].

Ultrasonic and radiological tests were compared in 267 patients suspected of having gall-stones. Radiological diagnosis was not possible in 20, because of lack of opacification, while in nine a gall-bladder was not demonstrable by ultrasound. In 226 the two tests coincided (positively or negatively), with 21 negative cholecystograms being interpreted as proof of stone. Seven of twelve discordant results were proven at operation: in three the ultrasonic, in four the radiological diagnosis was confirmed. Because of its accuracy, simplicity and absence of any risk ultrasonics is recommended as the first test to be performed if cholelithiasis is suspected.

Cholecystography↗