Search PubMed⌕ Search

Biomedical subjects

T Becker

Publications and source records attributed to T Becker.

At least 91 records · Page 5Linked to original sources
PubMed1997

[Clozapine in treatment of neuropsychiatric diseases in the elderly].

The atypical antipsychotic clozapine has been reported to be effective in otherwise refractory psychoses. This, and its low potential for inducing extrapyramidal side effects and tardive dyskinesia, predestines this drug for the treatment of psychotic disorders in late life. However, not much is known about the efficacy, safety and pharmacokinetics of clozapine in the treatment of aged patients. There are some studies and reports available about clozapine in the treatment of psychosis in patients suffering from dementia, schizophrenia and Parkinson's disease, which are reported here. They give some evidence that even low doses of clozapine are effective in controlling psychotic symptoms in the elderly. To avoid side effects, patient-specific factors and changes of pharmacokinetics in the elderly have to be considered. However, side effects including sedation, delirium, posturnal hypotension and the risk of agranulocytosis in particular limits the use of clozapine in elderly patients.

Aged↗
PubMed1997

Parkinson's disease and depression: evidence for an alteration of the basal limbic system detected by transcranial sonography.

OBJECTIVES: Depression is a frequent symptom in Parkinson's disease. Compelling evidence suggests a role of the brainstem in the control of mood and cognition. In patients with unipolar depression transcranial sonography (TS) studies have shown structural alteration of the mesencephalic brainstem raphe which could suggest an involvement of the basal limbic system in the pathogenesis of primary mood disorders. The objective of the present study was to evaluate whether a similar alteration could be found in depressed patients with Parkinson's disease using TS. METHODS: Thirty patients with Parkinson's disease and 30 age and sex adjusted controls were examined by TS. Raphe echogenicity was rated semiquantitatively. The severity of motor symptoms and depression was rated using standard research instruments. RESULTS: Raphe echogenicity was significantly reduced in depressed patients with Parkinson's disease compared with nondepressed patients with Parkinson's disease and control subjects. Raphe echogenicity correlated negatively with degree of motor impairment, and differences in raphe echo between depressed and non-depressed patients with Parkinson's disease were upheld when motor impairment was controlled for. CONCLUSION: These preliminary findings suggest that, as in unipolar depression, a morphological alteration of the brainstem raphe might be involved in the pathogenesis of depression in Parkinson's disease. This raphe alteration may reflect involvement in the basal limbic system in the pathogenesis of secondary depression. This concept is in line with current knowledge on the pathogenesis of both depression in Parkinson's disease and primary depressive disorders.

Aged↗
PubMed1997

Social networks and service use among representative cases of psychosis in south London.

BACKGROUND: Large social networks in patients with severe mental illness have been reported to be associated with a low rate of hospitalisation. We aim to determine whether social network size is related to the likelihood of hospitalisation and the amount of service use. METHOD: As part of a prospective controlled study, baseline interview data for a random sample of one-year prevalent cases with non-organic psychosis were analysed with respect to social network characteristics and service use during a six-month period. RESULTS: The likelihood of hospitalisation decreased with an increase in network size, while the number of services used by patients grew as the social network size increased. CONCLUSIONS: While larger social networks may be associated with a lower likelihood of hospitalization, they may also be related to wider use of non-hospital services.

Adolescent↗
PubMed1997

[Helicobacter pylori: pretherapeutic resistance status in Germany (Ruhr area)].

BASIC PROBLEM AND OBJECTIVE OF STUDY: The situation of pretherapeutical antimicrobial drug resistance of Helicobacter pylori has therapeutical implications. For this reason the present study was designed to evaluate the frequency of resistance in Germany. MATERIAL AND METHODS: A total of 201 H. pylori isolates cultured on the basis of biopsies taken by routine gastroscopies were tested for resistance by E-test. The antibiotics examined were amoxicillin, tetracycline, clarithromycin and metronidazole. For further analysis the last 101 patients were asked for demographical and clinical data that were evaluated for a correlation with metronidazole resistance. RESULTS: Pretherapeutical resistance against amoxicillin and tetracycline was not detected. The rate of drug resistance against clarithromycin came to 3% and against metronidazole to 29%. There was a higher incidence of metronidazole resistance in female patients (Odds ratio 1.71; p = n.s.). Reliable predictors for metronidazole resistance, however, could not be identified. CONCLUSIONS: About 30% of H. pylori isolates are pretherapeutically resistant to metronidazole. Resistance to clarithromycin is still rare, but further monitoring remains necessary to detect changes in the community.

Amoxicillin↗
PubMed1996

Is computerized tomography ventricular abnormality related to cycloid psychosis?

Twenty-eight psychiatric patients with computerized tomography (CT) findings of ventricular abnormality most likely to result from prenatal/perinatal lesions (VA group) were compared to 28 sex- and age-matched psychiatric patients with normal neuroradiological findings (NCT group). The neuroradiological rater was blind to clinical psychiatric diagnoses and, vice versa, clinical diagnoses were established without knowledge of neuroradiological findings. A polydiagnostic approach (DSM-III-R, ICD-10, Leonhard Classification) was used for psychiatric diagnostic workup. Significantly more patients with cycloid psychoses (according to Leonhard's original description) were found in VA as compared to NCT patients. According to DSM-III-R and ICD-10, VA and NCT groups did not differ significantly regarding diagnostic distribution. Ventricular abnormalities that may reflect sequels of birth complications and/or adverse events during pregnancy may constitute one of the risk factors for developing cycloid psychosis as originally described by Leonhard.

Adult↗
PubMed1996

Insertional mutagenesis in zebrafish identifies two novel genes, pescadillo and dead eye, essential for embryonic development.

Recently our laboratory described an efficient method for generating retroviral provirus insertions in the zebrafish germ line, and we showed that provirus insertions induce embryonic mutations at a frequency of roughly one mutant per 70 insertions. To date we have isolated four insertional mutants and, using the proviruses as a molecular tag, have cloned the genes disrupted in three of them. The proviruses in all three mutants lie within or just 5' of the first coding exon, point in the opposite transcriptional orientation from the gene, and disrupt transcription. Here we present a molecular characterization of two genes identified by this method and describe the associated mutant phenotypes. The pescadillo (pes) gene is predicted to encode a protein of 582 amino acids with no recognizable functional motifs, which is highly conserved from yeast to humans. pes mRNA is expressed widely and dynamically during the first 3 days of embryogenesis. Prominent sites of expression are the eyes and optic tectum on day 1, the fin buds, liver primordium, and gut on day 2, and the branchial arches on day 3. Beginning at day 3 of embryogenesis, pes mutant embryos exhibit small eyes, a reduced brain and visceral skeleton, shortened fins, and a lack of expansion of the liver and gut, and then die on the sixth day of development. The dead eye (dye) gene encodes a protein of 820 amino acids that is homologous to genes of unknown function in human, mouse, and Xenopus, and that has weak homology with the yeast NIC96 (nucleoporin-interacting component) gene. dye mutants can be recognized on day 2 of embryogenesis by the presence of necrotic cells in the tectum and eyes. dye mutants die on day 5 of development. These results demonstrate the power of insertional mutagenesis in zebrafish for rapidly finding and characterizing novel genes essential for embryonic development. Using our current methodology, we estimate that our laboratory could screen approximately 25,000 insertions in 2-3 years, identifying perhaps 250-350 embryonic lethal genes. Assuming that all genes are accessible to proviral insertion, the wider application of this approach could lead to the rapid identification of the majority of genes that are required for embryonic development of this vertebrate.

Amino Acid Sequence↗
PubMed1996

Insertional mutagenesis and rapid cloning of essential genes in zebrafish.

Large-scale chemical mutagenesis screens in zebrafish have led to the isolation of thousands of lethal mutations in genes that are essential for embryonic development. However, the cloning of these mutated genes is difficult at present as it requires positional cloning methods. In Drosophila, chemical mutagenesis screens were complemented with P-element insertional mutagenesis which facilitated the cloning of many genes that had been identified by chemical lesions. To facilitate the cloning of vertebrate genes that are important during embryogenesis, we have developed an insertional mutagenesis strategy in zebrafish using a retroviral vector. Here, in a pilot screen of 217 proviral insertions, we obtained three insertional mutants with embryonic lethal phenotypes, and identified two of the disrupted genes. One of these, no arches, is essential for normal pharyngeal arch development, and is homologous to the recently characterized Drosophila zinc-finger gene, clipper, which encodes a novel type of ribonuclease. As it is easy to generate tens to hundreds of thousands of proviral transgenes in zebrafish, it should now be possible to use this screening method to mutate and then rapidly clone a large number of genes affecting vertebrate developmental and cellular processes.

Amino Acid Sequence↗
PubMed1996

Confirmation of reduced temporal limbic structure volume on magnetic resonance imaging in male patients with schizophrenia.

A structural deficit in the temporal lobes has been implicated in the pathogenesis of schizophrenia. A prospective magnetic resonance imaging (MRI) study was carried out in 20 young male patients with schizophrenia and 20 age-matched healthy male volunteers. Volumetric measurements were performed in all slices with temporal lobe cross-sections from the temporal pole to the tip of the Sylvian fissure. Volumetric assessment included the temporal lobe as a whole, hippocampal formation and amygdala complex, temporal horn and cella media of the lateral ventricle, the third ventricle, and hemispheric volume in all slices that showed temporolimbic structures. Brain structural deficit in the patients was most conspicuous in the posterior portion of the hippocampal formation. Significant effects of diagnosis were also found for the total temporal lobe and the third ventricle. Multiple regression analysis revealed posterior hippocampal volume to be significantly determined by diagnosis, but not by age or by temporal lobe or hemispheric volume. Significant correlations of morphologic and clinical parameters were restricted to negative correlations of temporal lobe volume with the global rating and sum score of the Scale for the Assessment of Negative Symptoms. The study confirms subtle temporolimbic deficit reported in previous MRI studies in patients with schizophrenia.

Adult↗
PubMed1996

The polysialic acid modification of the neural cell adhesion molecule is involved in spatial learning and hippocampal long-term potentiation.

The alpha-2,8-linked polysialic acid (PSA) modification of the neural cell adhesion molecule (NCAM) modulates morphogenetic cell interactions. PSA is strongly expressed during neural development and generally down-regulated in the adult. However, it remains prominent in some areas of the brain, e.g., the hippocampus. We assayed the functional role(s) of PSA in synaptic plasticity in the hippocampus in two experimental paradigms by removing PSA with endo-neuraminidase NE (endo-N) an enzyme which specifically cleaves alpha-2,8-linked polysialic acid. (1) The acquisition and retention of spatial memory of rats in the Morris water maze, critically dependent on the hippocampus, was significantly impaired after a localized injection of endo-N into the hippocampus, whereas visual and motor capacities were unaffected. (2) Tetanic stimulation of the Schaffer collaterals in endo-N-treated hippocampal slices in vitro failed to elicit LTP and yielded only a short post-tetanic potentiation, but the response returned to control levels within 2 minutes, whereas basal synaptic activity and short-term potentiation were not affected. Our findings suggest that the carbohydrate epitope PSA plays an important role in synaptic plasticity.

Analysis of Variance↗
PubMed1996

[Ulcer healing through the elimination of Helicobacter pylori: is a week of therapy enough?].

AIM OF STUDY: To test whether one week's triple therapy with omeprazole and two antibiotics is enough to induce healing of a peptic (gastric and/or duodenal) ulcer. PATIENTS AND METHODS: 112 Patients (73 males, 39 females; median age 55 [18-88] years) proven by culture or histology to have an Helicobacter (H.) pylori infection and uncomplicated peptic (gastroduodenal) ulcer. For one week they received omeprazole (20 mg once or twice daily) plus two antibiotics (clarithromycin/metronidazole, clarithromycin/tetracycline, clarithromycin/amoxycillin or amoxycillin/metronidazole) to eradicate H. pylori. No further anti-ulcer treatment was given subsequently. Healing of the ulcer and H. pylori status were checked by the urease test, culture and histology (endoscopic biopsy) 4 weeks later. RESULTS: The 5-week ulcer healing rate was 94.6% (95% confidence interval: 89-98%). Persisting ulcers (n = 6) were associated with either treatment with aspirin or nonsteroidal antiinflammatory drugs (n = 3), persistent H. pylori infection (n = 2) or persistent H. pylori infection plus treatment with aspirin (n = 1). The ulcer healing rate was significantly higher in patients with eradicated infection than in those with posttherapy persistence of H. pylori (97.0 vs. 76.9%; P = 0.02). There were no significant differences after 5 weeks between patients with duodenal and those with gastric ulcer (97.4 vs. 89.3%). CONCLUSIONS: One-week effective eradication treatment is adequate to induce healing of H. pylori-positive peptic ulcers. Anti-ulcer treatment after eradication of H. pylori should be considered only if the patient is receiving treatment with ulcerogenic drugs or continues to have symptoms.

Adolescent↗
PubMed1996

Differential ontogenic pattern of metabotropic [3H]-L-glutamate receptors in normal and granule cell-deficient mouse cerebellum.

[3H]-L-glutamate binding site distribution corresponding to metabotropic receptors was studied by autoradiography during normal and altered cerebellar ontogeny in mice treated on postnatal days (PND) 5 and 6 with the antimitotic methylazoxymethanol (MAM). Quisqualate (QA)-induced and (2S,3S,4S)-alpha-(carboxycyclopropyl)-glycine (L-CCG-I)-induced [3H]-L-glutamate binding inhibition allowed us to distinguish between group I and group II metabotropic receptor binding sites. In control cerebellar cortex, the QA-sensitive binding site density increases during development, while the L-CCG-I-sensitive binding site density decreases. In the deep cerebellar nuclei (DCN), both populations of binding sites decrease during ontogeny. The antimitotic treatment induces: (1) a slight but significant increase in the QA-sensitive binding sites in the DCN at PND 10 and in the cerebellar cortex beginning from PND 20; (2) a retarded decrease in the L-CCG-I-sensitive metabotropic receptor binding site density. These differences could be due to a retarded cell maturation and/or an over-expression of some postsynaptic receptors in the adult cerebellum in response to the afference deficiency.

Amino Acids, Dicarboxylic↗
PubMed1996

One-week triple therapy with omeprazole, amoxycillin and either clarithromycin or metronidazole for cure of Helicobacter pylori infection.

AIM: The present study was designed to evaluate the efficacy and tolerability of 1-week triple therapy regimens for Helicobacter pylori. METHODS: In two consecutive series, 120 patients with proven H. pylori infection and peptic ulcer disease or functional dyspepsia were treated with either omeprazole 20 mg b.d., amoxycillin 1 g b.d. and clarithromycin 250 mg b.d. (OAC; n = 60) or with omeprazole 20 mg b.d., amoxycillin 1 g b.d. and metronidazole 400 mg b.d. over 1 week (OAM; n = 60). H. pylori infection was assessed by rapid urease test, culture and histology before and 4 weeks after cessation of the eradication therapy. RESULTS: H. pylori eradication succeeded in 53 out of 60 patients by omeprazole-amoxycillin-clarithromycin (OAC) (88%; 95% CI 77-95%) and in 47 out of 60 patients by omeprazole-amoxycillin-metronidazole (OAM) (78%; 95% CI 66-88%) (P = 0.22). Nine patients of each group available for follow-up reported adverse events (15.0 and 15.5%, respectively) without necessity of discontinuation of the study medications. Serious adverse events were not observed. CONCLUSIONS: Simple and convenient 1-week triple therapies consisting of omeprazole, amoxycillin and either clarithromycin or metronidazole are sufficiently effective in eradicating H. pylori infection.

Adolescent↗
PubMed1996

Trends in motor vehicle traffic fatalities among Hispanics, non-Hispanic whites and American Indians in New Mexico, 1958-1990.

OBJECTIVE: New Mexico has had the highest motor vehicle fatality rate in the nation for many years. Our objective was to examine ethnic differences and trends in motor vehicle fatality rates. DESIGN: Using death certificate data from the New Mexico Bureau of Vital Records and Health Statistics, we compiled age-adjusted motor vehicle-related mortality rates from 1958-1990 among the three major ethnic groups in New Mexico--Hispanics, white non-Hispanics and American Indians. RESULTS: Over the 33-year study period, American Indians of both sexes had two to three times higher mortality rates than white non-Hispanics. Hispanic males also had higher motor vehicle death rates than white non-Hispanic males. During the 1970s fatality rates peaked, with age-adjusted death rates of 233/100,000 for American Indian males, 74.7 for Hispanic males and 49.3 for white non-Hispanics for the period 1973-1977. Evaluation of successive 5-year birth cohorts showed highest mortality rates for ages 15-29 years for each ethnic group and both sexes, and a dramatic decline in most ethnic, sex and age-specific rates during the last eight years of the study period. CONCLUSION: Although the recent trends indicate favorable changes in motor vehicle fatality rates, our data highlight the need for ethnic and age-specific interventions to further reduce rates of motor vehicle-related mortality in this state.

Accidents, Traffic↗
PubMed1996

[Acute organic psychosis after malaria tropica].

Neuropsychiatric complications in the course of plasmodium falciparum infection are usually summarized as cerebral malaria. Heterogeneous clinical symptoms, different courses and inconstant parasitemia, however, suggest different pathogenic mechanisms. We report a case of an acute symptomatic psychosis occurring two weeks after successful therapy of a primary manifestation of plasmodium falciparum infection. The diagnosis of meningoencephalitis was based on lymphocytic pleocytosis of cerebrospinal fluid and hyperintense lesions in cranial magnetic resonance imaging. Due to the lack of plasmodium falciparum parasitemia and of serological evidence of viral infection a final diagnosis was not possible. Considering the pertinent literature, an immune-mediated complication of plasmodium falciparum infection (acute disseminated encephalomyelitis, ADEM) appears to be more probable than a direct viral or plasmodium CNS infection. We propose to reverse the term cerebral malaria for the cases with direct pathogenic influence of plasmodium falciparum, and to distinguish it from cases with possible immune-mediated pathogenesis.

Adult↗
PubMed1996

[Psychiatric sequelae of craniocerebral trauma--a review of the literature].

In a brief review psychiatric aspects of head-injured patients are discussed. The topic is put into a historical perspective. Examples of recent developments in head-trauma research are given. Differentiation between focal and diffuse brain injury is suggested to be of clinical relevance. Little is known as yet about the neuropsychologic and psychiatric sequelae of diffuse axonal injury to the brain.

Brain Concussion↗