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Biomedical subjects

M Bartels

Publications and source records attributed to M Bartels.

At least 73 records · Page 4Linked to original sources
PubMed1995

Do schizophrenics not differentiate between perception and imagination? an EEG study using dimensional analysis.

The electroencephalograms (EEGs) of 18 chronic schizophrenic patients and 16 controls were compared during three experimental conditions: simple mental arithmetic, the perception of a moving double pendulum, and the imagination of it. An elevated dimensional complexity of the EEG of schizophrenic patients during perception as compared to normals and a failure to increase dimensional complexity during mental imagery was found. No differences were found during mental arithmetic. It is concluded that the brains of schizophrenics operate during perception in a functional state that is characterised by increased and apparently unnecessary complexity.

Adult↗
PubMed1995

[What is the role of nutrition in ulcerative colitis? A contribution to the current status of diet therapy in treatment of inflammatory bowel diseases].

Nutritional therapy for ulcerative colitis (UC) is controversial. Studies are usually designed to investigate total parenteral (TPN) or total enteral nutrition (TEN), and before these can be compared it is necessary to differentiate between the different therapeutic aims. The aims of artificial nutritional support in patients with UC are the readjustment of the nutritional status, possible remission of disease activity, and decrease in the incidence of surgical intervention or postoperative complication. Owing to the heterogeneity of the results published so far, it is still difficult to compare studies. Nevertheless, they indicate that the extent and severity of the colitis and the patient selection are of paramount importance in the implementation of nutritional therapy. Positive effects of TPN reported from non-controlled studies were not confirmed by controlled trials. Moreover, TPN was no more effective than an oral diet. Regarding remission rates or operative interventions needed, TPN had more side effects than and no defined advantages over TEN. TEN seems to be useful for certain patients. In some patients with UC, it seems to be accompanied by fewer postoperative complications. However, a definitive conclusion on the effects of TEN or TPN is not yet possible. In this context, certain fatty acids may have an important role in the treatment of UC. In prospective, randomized and controlled studies omega-3 fatty acids were found to be therapeutically useful. A reduction of the steroid doses needed is particularly important. Another therapeutic approach in distal UC is seen in the rectal administration of short chain fatty acids.

Colitis, Ulcerative↗
PubMed1995

Detection of psychoactive drugs using 19F MR spectroscopy.

In vivo 19F resonance spectroscopy measurements of trifluorinated neuroleptics (fluphenazine and trifluoperazine) and later trifluorinated antidepressants (fluoxetine and fluvoxamine) began with animal experiments in 1983. Using rats which have been treated with high oral doses of fluphenazine over a period of three weeks in the beginning of these experiments the measurement time was very long (up to 10 h). The application of better techniques using surface coils led to marked improvement of the signal noise ratio and measurement times in animal experiments could be reduced to minutes. These results encouraged us and other groups to perform experiments in humans to detect and try to estimate brain levels of trifluorinated neuroleptics and antidepressants. The present data of several research groups demonstrate that 19F MR spectroscopy has the potential of becoming a valuable tool for monitoring drug levels at the site of action. The extension of the animal studies to humans might facilitate a better treatment of schizophrenic and depressive patients.

Animals↗
PubMed1995

Scanning electron-microscopic lesions in Crohn's disease: relevance for the interpretation of postoperative recurrence.

BACKGROUND/AIMS: Endoscopic postoperative recurrence often occurs a few months after surgical therapy for Crohn's disease, even if the resection margins were macroscopically free of disease. Why the disease primarily recurs at the anastomotic site is not known. This study investigated resection margins in Crohn's disease in an attempt to clarify whether early lesions are relevant to the interpretation of postoperative recurrence. METHODS: Specimens of surgically resected bowel from 29 patients with Crohn's disease and tissue from 11 controls were studied with a scanning electron microscope. RESULTS: In Crohn's disease, a triad of early lesions occurring in both histopathologically unaffected and affected mucosa was revealed; the triad consisted of mucosal architectural alterations, epithelial bridge formation, and goblet-cell hyperplasia or hypertrophy or both. Seventy-three percent of patients showed early alterations within histopathologically unaffected margins in the small bowel, and 71% had such alterations in the large bowel. CONCLUSIONS: The findings provide further evidence for the concept of diffuse involvement of the whole gastrointestinal tract by the disease process. The endoscopic recurrence rate in the first year after the operative procedure is almost identical to the number of early lesions present during surgery. The term "postoperatively recurrent disease" should be used only if relevant clinical parameters change.

Crohn Disease↗
PubMed1994

Early morphological changes in Crohn's disease. Transmission electron-microscopic findings and their interpretation: an overview.

Recent ultrastructural investigations revealed early epithelial lesions in Crohn's disease, while a specific morphological pattern was not identifiable. An increase in plasma cells, lymphocytes, macrophages, mast cells, eosinophilic and neutrophilic granulocytes, as well as focal edema and inflammation of tissue structures was seen in the lamina propria, submucosa and deeper layers. The results are consistent with the frequent discussion about a pathogenetically significant defect of the mucosal 'barrier function', which consists of mechanical, cellular, humoral, immunological and nonimmunological mechanisms, including different histotopographically defined lines of defense of the epithelium and lamina propria. An intact epithelial layer plays an important role as the first line of defense. It is evident that components of the epithelial barrier (absorptive cells, goblet cells, Paneth cells, M cells) show ultrastructural signs of alteration or injury, while the primary agent or event remains unknown. Another pathomechanism would be a preexisting defect in intestinal 'barrier function'. Such a defect would result in an increased uptake of, or an inadequate immune reaction to, ubiquitously occurring antigens/agents (with genetic predisposition). However, no primary defect of epithelial or inflammatory cells has been definitely identified so far. Direct toxic damage of tissue secondarily introducing the inflammatory changes is also possible. Although the morphological alterations in Crohn's disease are not yet clearly understood and exactly interpreted, transmission electron microscopy has been helpful in defining early lesions and has led to further knowledge about the pathogenesis of this disease.

Crohn Disease↗
PubMed1993

Comparison of schizophrenic delusions between Japan and Germany.

The content of schizophrenic delusions of 150 German patients in the Psychiatrische Universitätsklinik Tübingen and those of 324 Japanese patients (ICD-9:295) were compared according to the classification of Huber and Gross. The comparison revealed significantly higher frequencies of delusions of poisoning (18 vs. 8%; p < 0.01) and jealousy (6 vs. 1.9%; p < 0.05) in the German cases, but there was no significant difference in the incidence of comprehensive injury delusions. There was also no significant difference in the incidence of comprehensive grandeur delusions. However, comprehensive belittlement delusions were more frequent in the German group (24 vs. 13.3%; p < 0.01). Among the delusions of this type, the themes of guilt/sin (15.3 vs. 4.9%; p < 0.001), particularly those related to religion, were more frequent in the German group. Although religious delusions were more frequent in the German group (21.3 vs. 6.8%; p < 0.001), the difference regarding the incidence of 'delusions of world destruction' was not statistically significant. Among the persecution/injury delusions, themes of direct persecution from others (Verfolgungswahn) were conspicuous in the German group, whereas delusions of reference (Beziehungswahn) related to harassment, such as 'being slandered by others' or 'being known', were common in the Japanese group. Namely, the difference in the content of these persecution/injury delusions may derive from the different types of self in the two countries: the individually oriented self in Germany and the group-oriented self in Japan. Delusions of guilt/sin in the German group may reflect the characteristics of sin in Christianity.

Adult↗
PubMed1993

[Animal experiment studies of ultrastructural changes in the lamina propria of the ileum caused by dietary fats and comparison with cytopathology in Crohn disease].

Experimental investigations have shown alterations of the ileal mucosal surface after specific fat diets resembling early changes in Crohn's disease. An animal experiment in pigs has been conducted. After creation of an anisoperistaltic segment these were fed either a specific fat diet containing chemically processed, partially hydrogenated fats or a low fat control diet over a period of 3 months. Defined areas of the ileal lamina propria were examined by transmission electron microscopy with the underlying question to what extent ultrastructural alterations could be compared to Crohn's disease. In comparison to the control group these areas were characterized by a dense infiltration of "inflammatory" cells like lymphocytes, histiocytes, macrophages and plasma cells indicating a hyperplasia and activation of lympho-plasmocytotic cells. Additionally, a focal prominent infiltration of mast cells with degranulation was observed as well as a dilatation of axons with depletion of axonal organelles in half of the animals after fat-feeding. Compared to patients with Crohn's disease the results show obvious similarities. It is concluded, that chemically processed fats could cause direct stimulation of immunologically-specific and non-specific cells in the lamina propria mucosae or directly injure the intestinal mucosa with secondary infiltration of inflammatory cells into the lamina propria.

Animals↗
PubMed1992

Self-regulation of slow cortical potentials in psychiatric patients: schizophrenia.

Slow cortical potentials (SCPs) are considered to reflect the regulation of attention resources and cortical excitability in cortical neuronal networks. Impaired attentional functioning, as found in patients with schizophrenic disorders, may covary with impaired SCP regulation. This hypothesis was tested using a self-regulation paradigm. Twelve medicated male schizophrenic inpatients and 12 healthy male controls received continuous feedback of their SCPs, during intervals of 8 s each, by means of a visual stimulus (a stylized rocket) moving horizontally across a TV screen. The position of the feedback stimulus was a linear function of the integrated SCP at each point in time during the feedback interval. Subjects were required to increase or reduce negative SCPs (referred to pretrial baseline) depending on the presentation of a discriminative stimulus. The correct response was indicated by the amount of forward movement of the feedback stimulus and by monetary rewards. Schizophrenics participated in 20 sessions (each comprising 110 trials), while controls participated in 5 sessions. Compared with the healthy controls, schizophrenics showed no significant differentiation between negativity increase and negativity suppression during the first sessions. However, in the last 3 sessions, patients achieved differentiation similar to controls, demonstrating the acquisition of SCP control after extensive training.

Adult↗
PubMed1992

[What are the psychiatrist's expectations from nuclear magnetic resonance tomography and spectroscopy?].

Magnetic resonance imaging (MRI) of the brain has several advantages over CAT-scans (CT). MRI will gradually replace CAT-scans for most of the diagnostic examinations in psychiatry. MRI has an advantage in detecting discrete lesions of the brain. This is demonstrated by a review of MRI studies with schizophrenic and alcohol dependent patients. Magnetic resonance spectroscopy (MRS) is suitable for the in-vivo investigation of brain functions. MRS might provide the greatest advantage for future research in psychiatry. This is demonstrated by different studies, where the concentration and the kinetics of psychopharmacological agents in the brain were measured in-vivo.

Brain Damage, Chronic↗
PubMed1992

Pharmacotherapy of schizophrenia in Germany.

The practice of pharmacotherapy of schizophrenia in Germany is based both on clinical experience and research findings. Experience and studies emphasize that neuroleptic medication is severely limited by side effects including acute extrapyramidal syndromes and tardive dyskinesia. Comparing neuroleptic doses in both acute and maintenance therapy have clinicians encouraged to evaluate methods for treating patients with the lowest effective dose. Other studies have shown that the plasma level may be helpful when deciding which is the best treatment for the illness. More precise results for determining the optimum dose of antipsychotic compounds in the future may be available from positron emission tomography (PET), and from fluorine-magnetic-resonance spectroscopy (FMRS). The management of patients whose illness are refractory to conventional neuroleptics is also discussed. Benzamides and clozapine, both atypical neuroleptics, may be more effective than other available compounds for the severely ill, or for patients who are unable to tolerate the neurological side effects of typical neuroleptics.

Antipsychotic Agents↗
PubMed1992

[Results of electroconvulsive therapy in restrictive indications. A retrospective study of 15 years].

In Tübingen ECT is restricted to severely ill patients who do not respond to other somatic therapies; especially to patients with endogenous depression and pernicious catatonia. Between 1976 and 1990, 45 patients were treated with ECT, of whom 22 suffered from endogenous depression and 10 from pernicious catatonia. Thirteen patients with other diagnoses (schizophrenic and schizoaffective psychoses, borderline schizophrenia and obsessive-compulsive disorder) were treated with ECT for severe depressive states after failure of psychopharmacological therapy. A positive therapeutic response to ECT was observed in 46% of patients with endogenous depression and in all 10 with pernicious catatonia. In the patients with schizophrenia and schizoaffective psychosis, borderline schizophrenia and obsessive-compulsive disorder, an amelioration of the depressive or anxiety syndrome was observed only in individual cases. Side effects of ECT were transit syndromes (20%), reversible amnestic syndromes (20%) and cardiac arrhythmias (6%). According to our results, ECT is highly effective in therapy-resistant endogenous depression and pernicious catatonia, and therefore remains a necessary part of psychiatric therapy.

Adolescent↗
PubMed1992

[Experimental damage of the epithelial layer of the ileum by dietary fats: transmission electron microscopy findings and their comparison with cell pathology in Crohn disease].

Regarding the unknown pathogenesis of Crohn's disease repeatedly the importance of diet has been accentuated. Epidemiological, biochemical and animal experimental results have focused on a possible relationship between the consumption of chemically processed, partial hydrogenated fats and the development of regional enteritis. In this context an experimental animal model in pigs was designed to analyze, whether transmission electron microscopic alterations of ileal mucosa could be induced by forage of chemically processed fats. By creation of a retroperistaltic ileal segment the contact time between chyme and intestinal mucosa was prolonged. Our underlying question was to what extent disorders of the intestinal barrier function could be compared to Crohn's disease. Present study concentrates on the epithelial-cell-layer. It was shown that in comparison to the control animals the lamina epithelialis mucosae of all animals after fat-feeding was characterized by: sublethal lesion of the enterocytes/crypt-epithelial cells (shortening and alteration of the microvilli, degeneration of mitochondria, formation of autophagocytic vacuoles); goblet cell hyperplasia and increased production of mucus; focal appearance of intraepithelial lymphocytes as well as presence of polymorphonuclear granulocytes in the epithelium; widening of the intercellular-space locally up to total loss of the functional structure of the epithelial-cell-layer. In total the picture can be evaluated as an inflammatory process of the ileal mucosa. It can be concluded, that chemically processed fats as used in the described experimental conditions could induce this process. The feature of mucosal damage shows obvious similarities to ultrastructural findings in Crohn's disease if compared.

Animals↗
PubMed1991

19F nuclear magnetic resonance spectroscopy of neuroleptics: the first in vivo pharmacokinetics of trifluoperazine in the rat brain and the first in vivo spectrum of fluphenazine in the human brain.

In vivo 19F nuclear magnetic resonance (19F-NMR) spectroscopy measurements of trifluorinated neuroleptics (fluphenazine--FL and trifluoperazine--TFP) were made in rat brain as well as in human brain. Animal studies were performed at 4.7 Tesla. Using rats that have been treated with FL over a period of 3 weeks, a NMR signal could be detected within 8-15 min. Following a single intravenous injection of TFP, brain levels could be monitored with a time resolution of 30 min. The first 19F-NMR examination of a patient was made at 3.0 Tesla 1 day after injection of FL decanoate (37.5 mg) in the course of which a signal could be detected within 30 min. It is expected that 19F-NMR will become an important tool in psychopharmacological research.

Adult↗
PubMed1991

[Thiamine deficiency and brain atrophy in alcoholic patients].

CT brain scans of 65 alcohol-dependent inpatients were compared before and after 6 weeks of confirmed abstinence. Linear measurements revealed a significant reduction of the enlargement of the ventricular system in accordance with the re-expansion of the brain after alcohol abstinence (ANOVA, significant time effects). 22 patients showed a moderate or severe thiamine deficiency. CT findings on thiamine-deficient patients did not differ from those on patients without thiamine deficiency (ANOVA, no significant group effects). Correlations between thiamine deficiency and subcortical atrophy before treatment were not significant. The results are discussed in relation to the pathogenesis of reversible brain shrinkage in chronic alcoholics.

Adult↗
PubMed1990

In vivo 19F nuclear magnetic resonance spectroscopy of trifluorinated neuroleptics in the rat.

In vivo 19F NMR measurements of trifluorinated neuroleptics in the rat brain were made using a 13 x 18 mm surface coil at 4.7 T. The signal of fluphenazine was obtained within 8-15 min from brains of living rats treated chronically with drug doses of 5-30 mg/kg. Following the intravenous injection of a single dose of trifluoperazine (30 mg/kg), brain levels could be monitored with a time resolution of 30 min. The data demonstrate the possibility of obtaining in vivo pharmacokinetics of fluorinated agents in the rat brain. 19F NMR is expected to become an important tool in neurochemical research.

Animals↗
PubMed1990

MRI findings in medial temporal lobe structures in schizophrenia.

In an MRI volumetric study of 10 young male schizophrenics (DSM-III-R 295.9x) a temporal lobe segment, corresponding hippocampal formation and parahippocampal gyrus were found smaller as compared with healthy controls while temporal horn was enlarged. Temporal lobe segment and parahippocampal gyrus were larger on the right in patients and controls, reversed asymmetry was found for the hippocampus.

Adult↗
PubMed1990

A double-blind multicentre study comparing remoxipride, controlled release formulation, with haloperidol in schizophrenia.

A double-blind multicentre study was undertaken to compare the efficacy and safety of remoxipride in a controlled release (CR) formulation given once daily with haloperidol twice daily in patients with schizophrenic illness. In total, 114 patients were included. All were diagnosed as schizophrenic or schizophreniform according to DSM-III. Their mean daily dose of remoxipride CR during the last week of treatment was 385 mg. In the haloperidol group the corresponding dose was 17 mg per day. The intended study period was 4 weeks with at least a one-day washout. No significant differences were found between treatments regarding efficacy variables. The median total Brief Psychiatric Rating Scale (BPRS) score was 40 in the remoxipride CR group at start of treatment and 21 at last valid rating. For the haloperidol group the corresponding figures were 40 and 22. Treatment-emergent extrapyramidal symptoms (Simpson and Angus rating) occurred statistically significantly more frequently and were more severe during haloperidol than during remoxipride CR treatment despite a statistically significantly higher concurrent use of anticholinergic drugs in the haloperidol group.

Acute Disease↗