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Biomedical subjects

B Lerer

Publications and source records attributed to B Lerer.

At least 145 records · Page 8Linked to original sources
PubMed1991

Early and long-term effects of electroconvulsive therapy and depression on memory and other cognitive functions.

Twenty-seven medication-free, depressed patients (Research Diagnostic Criteria, endogenous subtype) were administered a comprehensive battery testing memory and other cognitive functions before and after a series of bilateral, brief-pulse electroconvulsive therapy (ECT) administered according to a dosage-titration procedure (8.9 +/- 1.981 treatments). A subset of patients (N = 14) were reexamined at 1 month and 6 months after the conclusion of the treatment. Anterograde (verbal and visuospatial tasks), as well as retrograde (famous and personal events), memory function was significantly impaired at the end of the ECT series. By 1 month follow-up, performance had improved to pre-ECT (depression) levels on both anterograde and retrograde tasks and exceeded these by 6 months. The memory deficits induced by ECT were not a consequence of generalized cognitive impairment. Furthermore, depression and ECT were shown to independently affect memory, and recovery from depression was not a consequence of the amnestic action of the treatment. The results generally confirm previous reports regarding the nature of ECT-induced memory impairment, in a different language and culture. They suggest that long-term effects of the treatment on memory are even less prominent than previously observed.

Adult↗
PubMed1991

Performance of long-stay schizophrenics after drug withdrawal on matched immediate and delayed recall tasks.

Both anticholinergic and neuroleptic drugs were withdrawn from eight long-stay hospitalized chronic schizophrenics. These patients and normal controls were then tested on Calev, Venables & Monk's (1983) immediate and delayed matched recall tasks to evaluate their rate of forgetting of verbal well-encoded materials. The results showed rapid forgetting in schizophrenics. This finding suggests that a post-encoding deficit characterizes long-stay schizophrenics after drug withdrawal. Cognitive and brain pathologies that may explain these results are discussed.

Adult↗
PubMed1991

Reminiscing as a technique in the group psychotherapy of depression: a comparative study.

Reminiscing as a technique of group psychotherapy for severely depressed hospitalized patients was found by patients and staff to be more efficacious than the traditional reflective non-directive group psychotherapy approach. The therapeutic potential of reminiscing in combatting depressed mood was supported by the present findings. The suitability of reminiscing to the difficult task of handling groups of severely depressed hospitalized patients was demonstrated.

Depressive Disorder↗
PubMed1991

Optimal use of electroconvulsive therapy: choosing a treatment schedule.

Choice of treatment schedule is an important component of the ongoing efforts to optimize electroconvulsive therapy (ECT) administration and thereby maximize therapeutic benefit while reducing cognitive adverse effects. Frequency of ECT administration (that is, the spacing between treatments) and the total number of treatments in a series are the two factors that define the ECT schedule. Available evidence supports the view that a schedule of twice weekly ECT with a total of six to eight treatments is an effective therapeutic regiment that potentially reduces cognitive morbidity associated with more frequent administration and a larger number of treatments. More frequent administration, however, may accelerate antidepressant response and may be indicated in cases in which rapidity of therapeutic effect is a significant clinical consideration. This consideration may be at the cost of greater cognitive impairment, which could be reduced by limiting the number of treatments administered. Aside from their clinical relevance, these issues have important implications for understanding the mechanisms of action of ECT.

Depressive Disorder↗
PubMed1990

Platelet adenylate cyclase and phospholipase C activity in posttraumatic stress disorder.

Adenylate cyclase and phospholipase C activity were examined in platelet membranes obtained from 19 male subjects with combat-related posttraumatic stress disorder (PTSD) and 35 age- and gender-matched healthy controls. Basal and forskolin-stimulated adenylate cyclase activity were significantly lower in the PTSD group whereas aluminum chloride plus sodium fluoride (AlCl3/NaF)- and prostaglandin E1 (PGE1)-stimulated responses were normal. There was no difference in phospholipase C activity between the two groups. The lower basal and forskolin-stimulated adenylate cyclase responses replicate a previous report and suggest that PTSD may be associated with an abnormality of the catalytic subunit of the receptor-adenylate cyclase complex.

Adenylyl Cyclases↗
PubMed1990

Cyclic AMP second messenger signal generation in EBV-transformed lymphoblastoid cells from schizophrenic patients.

Several aspects of cyclic AMP second messenger signal generation were examined in EBV-transformed cell lines from 12 schizophrenic patients and 12 age- and sex-matched controls. No evidence was obtained suggesting a heritable abnormality in cyclic AMP synthesis in schizophrenia. Basal, forskolin, A1/NaF- and GppNHp-stimulated cyclic AMP synthesis in membranes from transformed cell lines was identical for schizophrenic and control subjects. In addition, no significant differences were observed for basal, forskolin-, isoproterenol- and prostaglandin E1-stimulated cyclic AMP accumulation in intact cell lines derived from ten of the schizophrenic patients compared with cell lines derived from ten of the control subjects.

Adenylyl Cyclases↗
PubMed1990

Single and combined effects of desimipramine and lithium on serotonergic receptor number and second messenger function in rat brain.

The effects of chronic administration of desimipramine (DMI, 10 mg/kg i.p. daily for 4 or 5 weeks), short-term administration of lithium (Li, 0.2% in food for 10 days) and a combination of these treatments on serotonergic receptors and second messengers were studied in the rat brain. DMI alone had no effect on [3H]5-HT binding but reduced [3H]ketanserin binding in cortical membranes, 5-HT-stimulated inositol phosphate (IP) formation in cortical slices and the degree of inhibition of forskolin-stimulated adenylate cyclase by 5-HT in hippocampal membranes. Li alone reduced [3H]5-HT binding and the degree of inhibition of forskolin-stimulated adenylate cyclase by 5-HT in hippocampal membranes, and also reduced [3H]ketanserin binding and 5-HT-stimulated IP formation in the cortex. The two treatments combined in general produced effects similar to those of Li alone, but the decrease in [3H]ketanserin binding in cortical membranes was significantly greater than that given by Li alone, whereas the reduction in the degree of inhibition of forskolin-stimulated adenylate cyclase by 5-HT in hippocampal membranes was significantly greater than that produced by DMI alone. It is concluded that the therapeutic action of Li when added to tricyclic antidepressants in the treatment of refractory depression may partly have its basis in potentiation of effects on the serotonergic system in the brain.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1990

Core symptoms of posttraumatic stress disorder unimproved by alprazolam treatment.

The authors report a random-assignment, double-blind crossover trial comparing alprazolam and placebo in posttraumatic stress disorder (PTSD). Ten patients fulfilling DSM-III criteria for PTSD completed 5 weeks of treatment on each agent. Improvement in anxiety symptoms was significantly greater during alprazolam treatment but modest in extent. Symptoms specific to PTSD were not significantly altered. The impact of nonspecific symptomatic effects on the outcome of drug trials in PTSD is considered.

Adult↗
PubMed1989

Post-receptor-mediated increases in adenylate cyclase activity after chronic antidepressant treatment: relationship to receptor desensitization.

Administration to rats of chronic electroconvulsive shock (ECS) or chronic desipramine (DMI, 10 mg/kg daily i.p. for 3 weeks) did not affect either basal or forskolin-stimulated adenylate cyclase activity in membranes prepared from the caudate nucleus. In cerebellar membranes prepared from rats which had received chronic ECS, forskolin-stimulated activity was significantly increased compared to activity in sham- or single ECS treated rats. Forskolin-stimulated adenylate cyclase was increased in both hippocampal and cerebellar membranes from rats which received chronic DMI, compared to saline-treated animals. In cerebellar membranes, increases comparable to those with forskolin were also obtained with guanylyl-5'-imidodiphosphate (GppNHp) after both treatments, while with Mn2+ ions, either alone or in the additional presence of forskolin, the changes observed were similar to those previously reported in cortical membranes. A possible mechanism for these effects was investigated by studying antidepressant-induced and in vitro desensitization of the cyclic AMP response in slice preparations from the various brain areas. In slices from caudate nucleus, chronic DMI did not alter stimulation of cyclic AMP formation by either noradrenaline or forskolin, while in cerebellar slices the noradrenaline response was significantly reduced, and in hippocampal slices both responses were reduced (heterologous desensitization). In vitro incubation of cortical slices with noradrenaline also resulted in a reduction in the response to both agents. However, in membranes prepared from the desensitized cortical slices, there was no change in the degree of activation of adenylate cyclase by either NaF or forskolin. Thus, the increase in these activities, observed in certain brain areas after chronic antidepressant treatment may not necessarily be related to beta-adrenoceptor desensitization.

Adenylyl Cyclases↗
PubMed1989

Peripheral versus central manifestations in the toxic interaction of lithium and pilocarpine.

Administration of a cholinomimetic agent 24 hr after a single injection of lithium chloride results in a profoundly toxic interaction. The lethality of the interaction was completely blocked by prior administration of scopolamine, but was not reduced by the peripherally acting cholinergic antagonist methscopolamine. Examination of the relative time courses of central neurotoxic and peripheral cholinergic manifestations showed that the peripheral manifestations were transient and were not enhanced by lithium pretreatment. The profoundly toxic consequences of lithium-cholinomimetic interaction may thus occur in the absence of enhanced cholinergic function in the periphery.

Animals↗
PubMed1989

Uptake of 3H-spiperone by lymphocytes in schizophrenia.

Uptake of 3H-spiperone into lymphocytes obtained from control subjects (N = 22), chronic schizophrenics (N = 20), relatives with psychiatric disorder (N = 11) and unaffected relatives (N = 17) was studied. No differences were observed in spiperone uptake among any of the groups examined. Although previous investigations reported marked differences in 3H-spiperone uptake between schizophrenic and control subjects, we were unable to replicate their findings: the failure to replicate those of Bondy and colleagues may well be due to our inability to duplicate in our laboratory the exact biochemical methodology described by these investigators. Saturation curves could not be determined for most subjects. In addition, chronicity of illness and long-term exposure to neuroleptic medication among the schizophrenic subjects may partially account for the contradictory results reported by different investigators.

Adult↗
PubMed1989

Effects of chronic electroconvulsive shock on D1 and D2 dopamine receptor-mediated activity of adenylate cyclase in homogenates of striatum and limbic forebrain of rat.

Stimulation of adenylate cyclase by dopamine in homogenates of the striatum was unaltered in rats which had received either a single or a series of 10 electroconvulsive shock, compared to those which received sham treatment. In homogenates of the limbic forebrain, stimulation by both 100 microM dopamine and by 4 microM SKF 38393 was significantly increased after chronic electroconvulsive shock. The activity of D2 receptors, as measured by inhibition of forskolin-stimulated adenylate cyclase, in the presence of the D1 receptor antagonist SCH 23390, was unaltered by chronic electroconvulsive shock in either area of the brain. The selective effect of chronic electroconvulsive shock in increasing the activity of D1 receptors may account both for the increase, in dopamine-mediated behaviour, seen after chronic electroconvulsive shock and for the antiparkinsonian effects of this treatment.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1989

Modulation of second messenger function in rat brain by in vivo alteration of receptor sensitivity: relevance to the mechanism of action of electroconvulsive therapy and antidepressants.

1. The second messengers cyclic AMP and inositol triphosphate are the intracellular mediators for a number of neurotransmitters for which receptors exist on brain neurons. 2. Up- or down-regulation of these receptors in general produce corresponding changes in the associated second messenger systems. 3. Chronic administration of antidepressants including electroconvulsive shock to rats produces a number of changes in cerebral receptors, notably down-regulation of beta-adrenergic and serotonin 5-HT2 receptors and up-regulation of alpha-1 adrenergic receptors. 4. The changes in receptor number induced by such antidepressant treatments are in general accompanied by corresponding changes in the associated second messenger reactions. 5. Antidepressant administration has also been shown to induce increased post-receptor mediated adenylate cyclase activity in cortical membranes, and similar effects have also been reported in striatum after chronic administration of neuroleptics. The relevance of these effects to the mechanism of action of the drugs is discussed.

Animals↗
PubMed1989

Distinct memory impairments following electroconvulsive therapy and imipramine.

Memory functioning was assessed in 26 unmedicated patients with major depressive disorder (DSM-III) who were then administered either bilateral electroconvulsive therapy (ECT) (N = 16) or imipramine 200 mg per day (N = 10). The subjects were retested following seven ECT administrations or 21 days of imipramine treatment respectively. The retrograde memory tasks included recall of public and autobiographic events. The anterograde memory tasks included an immediate memory task, a verbal paired-associates recall task, and a non-verbal figure reproduction task. Depression was significantly improved in the ECT-treated subjects but not in those administered imipramine. Both ECT- and imipramine-treated patients showed a deficit in recent anterograde memory relative to their pretreatment performance, but no deficit in immediate memory. ECT-treated patients also had a significant and well-characterized impairment in retrograde remote memory. By contrast, imipramine-treated patients did not show a retrograde memory impairment which could be explained by treatment. The results suggest qualitatively different memory deficits produced by ECT and imipramine.

Depressive Disorder↗
PubMed1989

Prescribing patterns of neuroactive drugs in 98 schizophrenic patients.

Ninety-eight schizophrenic outpatients receiving pharmacotherapy were surveyed on two census days, 18 months apart. From this study sample it was found that, as recently as 1987, 18% of the patients were prescribed three classes of neuroactive drugs--16% two antipsychotic drugs simultaneously. Of antipsychotics receivers, 44% were prescribed anticholinergics, 3% antidepressants, and 4% benzodiazepines. Between census days, a significant shift from use of oral antipsychotics to the depot form of administration occurred, while polypharmacy frequency remained unchanged. An analysis of the data will provide guidelines for rendering a more rational pharmacological treatment.

Adolescent↗
PubMed1988

Effects of lithium and desipramine administration on agonist-stimulated inositol phosphate accumulation in rat cerebral cortex.

The effects of acute lithium and chronic desipramine administration on the inositol phosphate responses of rat cerebral cortical slices to noradrenaline, carbachol and 5-hydroxytryptamine, were determined. Acute injection of lithium (4 meq/kg s.c. 24 hr before sacrifice) significantly increased the inositol-1-phosphate response to noradrenaline, while chronic administration of desipramine (10 mg/kg i.p. for 3 weeks) produced a smaller increase in this parameter. Chronic desipramine also decreased the serotonin responses in terms of all three inositol phosphates measured. No potentiative or additive interactions between the lithium and desipramine effects were observed.

Animals↗