Search PubMed⌕ Search

Biomedical subjects

J Gerlach

Publications and source records attributed to J Gerlach.

At least 127 records · Page 7Linked to original sources
PubMed1985

Behavioral aspects of serotonin-dopamine interaction in the monkey.

The effects of serotonin (5-hydroxytryptamine; 5-HT) antagonists and 5-HT uptake inhibitors on the behavioral response to amphetamine and haloperidol in monkeys (cercopithecus aethiops) were investigated. Amphetamine increased locomotor activity and reactivity and induced repetitive movements of head, limbs and trunk, but no oral hyperkinesia. Haloperidol induced dystonia and parkinsonism. Pretreatment with the 5-HT antagonists cyproheptadine and mianserin increased amphetamine-induced locomotor activity, reactivity and repetitive movements and decreased haloperidol-induced dystonia and parkinsonism. Conversely the 5-HT uptake inhibitors paroxetine and CGP 6085 A decreased amphetamine-induced repetitive movements and aggravated haloperidol-induced dystonia and parkinsonism. The 5-HT uptake inhibitors produced oral hyperkinesia resembling human tardive dyskinesia, which was intensified by amphetamine and blocked by haloperidol. These findings support the suggestion that 5-HT inhibits dopamine functions and may imply that 5-HT antagonists could have a beneficial effect against acute extrapyramidal side-effects of neuroleptic treatment. 5-HT uptake inhibitors in the monkey may serve as a model for tardive dyskinesia.

Animals↗
PubMed1985

Pathophysiological mechanisms underlying tardive dyskinesia.

Movement abnormalities in neuroleptic-treated, psychiatric patients are classified as (a) initial syndromes, including dystonia, parkinsonism, and hyperkinetic abnormalities such as initial dyskinesia (ID) and akathisia, all of which are related to the neuroleptic dose and can be considered as overdose phenomena; (b) tardive syndromes, mainly the classic tardive dyskinesia (TD) syndrome, more seldom tardive akathisia and tardive dystonia, which may all develop or aggravate after withdrawal of neuroleptic treatment; and (c) age-related, spontaneous dyskinesia, akathisia, and dystonia, and schizophrenia-related, hyperkinetic, often stereotyped, movements and restlessness. ID and TD can occur simultaneously, and may depend, at least partially, on identical mechanisms. The pathophysiology of TD is still not clear, and the traditional dopamine (DA) hypersensitivity model seems inadequate. Animal experiments suggest that blockade of some DA receptors in the brain (e.g., in ventromedian striatum) may counteract hyperkinesia and produce parkinsonism, while a concomitant blockade of other similar receptors in other brain regions (e.g., in anterodorsal striatum) may aggravate movements. This offers an explanation for the concomitant occurrence of parkinsonism and hyperkinetic movement abnormalities (ID and akathisia) relatively early in a neuroleptic treatment, and may also contribute to the understanding of the pathophysiology of TD. It is concluded that pathophysiologically TD is a heterogeneous syndrome depending on a subtle balance between several neurotransmitters in the brain, including DA receptor blockade and hypersensitivity of DA and GABA receptors.

Antipsychotic Agents↗
PubMed1985

Tolerability and therapeutic effect of clozapine. A retrospective investigation of 216 patients treated with clozapine for up to 12 years.

Two hundred and sixteen psychiatric patients (183 men and 33 women) hospitalized in Sct. Hans Hospital were treated with clozapine between 1971-1983. All had been treated previously with one or more neuroleptic(s) and had either failed to respond adequately, or their response was limited by side effects. Eighty-five patients were treated exclusively with clozapine, while the remaining 131 received additional medication, mainly other neuroleptic drugs. The mean clozapine dosage was 317 mg/day (range 50-1200), and the mean duration of treatment was 23/4 years (range 1/12-12). The tolerability to clozapine was determined by an evaluation of haematological changes, pronounced side effects and mortality. One patient treated with clozapine (8 months) and nitrofurantoin (8 days) developed a reversible granulocytopenia. One patient (treated with a combination of drugs) had clinically insignificant depression of the leucocytes and three of segmented granulocytes. Seven had a reduction in thrombocytes. Two patients developed cardiac insufficiency, and four epileptic seizures. None of the patients treated exclusively with clozapine developed neurological side effects. A global estimation of therapeutic effect revealed that clozapine alone or in combination with other neuroleptic drugs was significantly better than previous antipsychotic therapy, although 47-63% of the patients showed no change. It is concluded that clozapine is a potent antipsychotic drug offering particular advantages in the treatment of schizophrenic patients with a pronounced symptomatology and tendency towards developing extrapyramidal side effects. Caution is advised in patients with cardiac insufficiency and epilepsy. There appears to be a slight risk of granulocytopenia, and therefore the present monitoring of WBC should continue in order to prevent this reaction and to obtain more complete information regarding risk of granulocytopenia.

Adolescent↗
PubMed1985

Sulpiride and haloperidol in schizophrenia: a double-blind cross-over study of therapeutic effect, side effects and plasma concentrations.

In a double-blind cross-over trial, 20 chronic schizophrenic patients were treated with sulpiride and haloperidol in two 12-week periods. The final median dose of sulpiride was 2000 mg/day (range 800-3200) and of haloperidol 12 mg/day (range 6-24). Sulpiride had an antipsychotic effect and therapeutic profile not significantly different from that of haloperidol. In spite of the high doses of sulpiride, extrapyramidal side-effects were seen less frequently during the first four weeks of the sulpiride period than during the corresponding haloperidol period (P less than 0.05), whereas autonomic side-effects were equally rare for both drugs. A positive correlation was found between daily dose and plasma concentration of both sulpiride (P less than 0.001) and haloperidol (P less than 0.05), but no correlation could be established between clinical effects and plasma levels of either neuroleptic.

Adolescent↗
PubMed1985

Evaluation of trachea kinetics in men and beagle dogs as a basic information for prosthesis construction.

Morphometric investigations on trachea kinetics in man and beagle dogs were undertaken to find out the range of motility in different moving planes. The results show a special mechanism of load distribution over the whole organ during movement. The minimal and the mean values for bending and torsion were recorded and made reproducible for to examine a trachea prosthesis in laboratory tester on its suitability for organ replacement.

Adult↗
PubMed1984

Methylphenidate, apomorphine, THIP, and diazepam in monkeys: dopamine-GABA behavior related to psychoses and tardive dyskinesia.

In eight monkeys (Cercopithecus aethiops), previously treated with haloperidol for 4-14 months, we have examined the behavioral effect of: (1) methylphenidate vs apomorphine; (2) 4,5,6,7-tetrahydroisoxazolo-(5,4-c)-pyridin-3-ol(THIP, a GABA agonist) vs diazepam; and (3) THIP and diazepam in methylphenidate-induced behavior. Methylphenidate (0.5-5.0 mg/kg) and apomorphine (0.1-0.5 mg/kg) both increased locomotion, but otherwise exhibited different behavioral profiles. Methylphenidate induced repetitive movements of head, limbs, and trunk, and hallucinatory-like behavior, but not oral hyperkinesia (licking and gnawing), whereas apomorphine preferentially caused oral hyperkinesia. THIP produced a syndrome of bradykinesia, dystonia, ataxia, myoclonus, sedation, and decreased responsiveness, whereas diazepam produced only bradykinesia, ataxia, sedation, and decreased responsiveness, but not dystonia and myoclonus. Methylphenidate-induced locomotion and repetitive movements were reduced by THIP and diazepam, whereas hallucinatory-like behavior was markedly aggravated by THIP, but not by diazepam.

Animals↗
PubMed1984

Effect of a cholinomimetic drug (RS 86) in tardive dyskinesia and drug-related parkinsonism.

RS 86, a specific muscarinic agonist, was evaluated in a blind, placebo-controlled, single-dose trial in 10 psychiatric patients with stable tardive dyskinesia (TD). RS 86, 0.5-4 mg orally, produced no significant effects in TD, although 4 mg caused a minimal aggravation in parkinsonism. Side effects of the highest dose (4 mg) included hypersalivation (eight patients), nausea (6), sweating (3), and vomiting (3). It is concluded that treatment with RS 86 and probably other cholinomimetics has no or only limited beneficial effect in TD.

Adult↗
PubMed1984

Fluperlapine in tardive dyskinesia and parkinsonism.

Fluperlapine, a new clozapine-like neuroleptic drug with weak affinity for dopamine receptors, was evaluated in a blind, placebo controlled trial in 11 patients with stable hyperkinesia (ten with tardive dyskinesia (TD) and one with spontaneous dyskinesia). Drug effects during active treatment (200-600 mg/day) and during pre- and post-treatment placebo periods were determined by scoring randomly sequenced videotapes of TD and parkinsonian symptoms recorded weekly during standardized examinations. TD score was unchanged, while parkinsonism slightly decreased (P less than 0.05) and eye-blinking rates increased (P less than 0.05). Psychiatric symptoms showed no significant changes, although positive psychotic symptoms diminished in four patients. Side effects included dizziness, sedation and constipation. The effects in movement disorders found in this study may imply that fluperlapine is less liable than traditional neuroleptics to induce acute extrapyramidal side effects and tardive dyskinesia and is particularly beneficial in the treatment of patients vulnerable to neurological side-effects.

Adult↗
PubMed1984

Multidrug resistance.

Mutations resulting in a complex phenotype of cross-resistance and collateral-sensitivity are frequently observed in mammalian cell lines. A cell surface 170 000 dalton glycoprotein (P-glycoprotein) has been identified to be intimately associated with this multidrug resistance phenotype. We speculate that such mutations also occur in advanced cancers and play a major role in contributing to the non-response to combination chemotherapy. In this context, P-glycoprotein may be a useful molecular marker for diagnostic and therapeutic applications.

ATP Binding Cassette Transporter, Subfamily B, Mem↗