Design, Synthesis and Anticonvulsant Activity of Cinnamoyl Derivatives of 3,4,6,7,8,9-hexahydrodibenzo[b,d]furan-1-(2H)-one Oxime

BACKGROUND

Epilepsy continues to be a significant global health problem and the search for new drugs for its treatment remains an urgent task. 5-HT2 and GABAA-receptors are among promising biotargets for the search for new anticonvulsants.

METHODS

New potential 5-HT2 and GABAA ligands in the series of substituted cinnamoyl derivatives of 3,4,6,7,8,9-hexahydrodibenzo[b,d]furan-1-(2H)-one oxime were designed using pharmacophore model and molecular docking analysis. The synthesis of new compounds was carried out from 3,4,6,7,8,9-hexahydrodibenzo[b,d]furan-1(2H)-one oxime and substituted cinnamoyl chlorides. The anticonvulsant activity of new substances has been established using the maximal electroshock seizure test.

RESULTS

Several synthesized substituted cinnamoyl derivatives of 3,4,6,7,8,9-hexahydrodibenzo [b,d]furan-1-(2H)-one oxime significantly reduced the severity of convulsive manifestations and completely prevented the death of animals after MES. The structure-activity relationship was investigated. The most effective compound was found to be GIZH-348 (1g) (3,4,6,7,8,9-hexahydrodibenzo[ b,d]furan-1(2Н)-one О-(4-chlorophenyl)acryloyl)oxime) at the doses of 10-20 mg/kg.

CONCLUSION

Molecular and pharmacophore modelling methods allowed us to create a new group of substituted cinnamoyl derivatives of 3,4,6,7,8,9-hexahydrodibenzo[b,d]furan-1-(2H)-one oxime with anticonvulsant activity.

Electrophysiological, histopathological, and biochemical evaluation of the protective effect of probiotic supplementation against pentylenetetrazole-induced seizures in rats

BACKGROUND AND PURPOSE

Research on the relationship between the gut microbiome and epilepsy is accumulating. The present study was conducted to evaluate the effect of probiotic supplementation on pentylenetetrazole (PTZ)-induced seizures in rats.

METHODS

Twenty-one adult male Wistar albino rats were included. The animals were divided into three groups of seven rats. Group 1 was a control group, whereas Group 2 rats received PTZ treatment and Group 3 rats had PTZ+PB (probiotic) treatment. For 6 weeks, Groups 1 and 2 were given saline (1 ml), whereas Group 3 had probiotic supplement. In the 5th week, tripolar electrodes were attached to the rats. Electrophysiological, behavioral, biochemical, and immunohistochemical evaluations were performed in the 6 weeks after the treatment.

RESULTS

PB treatment significantly reduced seizures. In the PTZ group, expression levels of brain-derived neurotrophic factor, nerve growth factor (NGF), and Sox2 (SRY sex-determining region Y-box 2) in rat brains decreased significantly compared to the control group, whereas the expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), total oxidant status (TOS), and nitric oxide (NO) levels increased. In the PTZ+PB group, NGF expression increased significantly compared to the PTZ group, whereas TNF-α, IL-6, TOS, and NO levels decreased. In histopathological examination, an abundance of necrotic neurons was notable in the PTZ group, which was less in the PTZ+PB group. In addition, body weight of the group supplemented with probiotics decreased after the treatment.

CONCLUSIONS

Our results suggest that probiotic supplementation may alleviate seizure severity and exert neuroprotective effects by reducing neuroinflammation and oxidative stress and altering the expression of neurotrophins in epileptogenic brains.

Exploring the early history of convulsive therapies at the Mysore Government Mental Hospital (currently NIMHANS)

OBJECTIVE

The paper describes the introduction, and early use of chemically and electrically induced convulsive therapies, at the Mysore Government Mental Hospital (MGMH), now the National Institute of Mental Health and Neuro Sciences, Bangalore, India. Cardiazol and ammonium chloride were used at MGMH before the introduction of electroconvulsive therapy (ECT). The study examines the early history, clinical correlates and outcome of convulsive therapies and attempts to contextualize how local conditions influenced implementation.

METHOD

Three sets of archival case-records from 1938 to 1948, each of a period of 9 months following the implementation of a particular mode of convulsive therapy were reviewed.

RESULTS

During the examined timeframe, 40 patients received cardiazol, 95 ammonium chloride and 50 unmodified ECT. Schizophrenia was the commonest clinical indication for convulsive therapy across all modalities of treatment. When outcomes were examined, 45%, 48.4% and 62% of patients were clinically reported to have been either cured/improved after receiving cardiazol, ammonium chloride and ECT respectively. Those receiving cardiazol had a high mortality of 22.5%, compared to 3.1% for ammonium chloride and 4% with ECT.

CONCLUSIONS

Convulsive therapies were one of the first somatic psychiatric treatments, introduced around 1930s and 1940s all over the world, including in India. Our archival records suggest that many international ideas about somatic treatments were quickly adopted in India. Electroconvulsive therapy and other novel neuromodulatory interventions continue to be used and actively researched in India.

Study of fingolimod, nitric oxide inhibitor, and P-glycoprotein inhibitor in modulating the P-glycoprotein expression via an endothelin-sphingolipid pathway in an animal model of pharmacoresistant epilepsy

BACKGROUND

The overexpression of P-glycoprotein (P-gp) contributes to drug resistance in patients with epilepsy, and the change of P-gp expression located at the blood-brain barrier alienates the anti-seizure effects of P-gp substrates. Thus, the present study explored the effect of fingolimod (FTY720) acting through an endothelin-sphingolipid pathway on P-gp-induced pentylenetetrazol (PTZ)-kindled phenobarbital (PB)-resistant rats.

MATERIALS AND METHODS

PTZ kindling (30 mg/kg; i.p.) and PB (40 mg/kg; orally) were used to develop an animal model of refractory epilepsy. The effect of Fingolimod on seizure score (Racine scale), plasma and brain levels of PB (high-performance liquid chromatography), and blood-brain barrier permeability (Evans blue dye) was determined. Further, Fingolimod's neuroprotective effect was determined by measuring the levels of various inflammatory cytokines, oxidative stress parameters, and neurotrophic factors in rat brain homogenate. The Fingolimod's effect on P-gp expression was estimated by reverse transcriptase-polymerase chain reaction and immunohistochemistry in rat brain. The H and E staining was done to determine the neuronal injury.

RESULTS

Fingolimod significantly (P < 0.001) reduced the seizure score in a dose-dependent manner and alleviated the blood-brain barrier permeability. It decreased the P-gp expression, which further increased the brain PB concentration. Fingolimod significantly (P < 0.01) reduced oxidative stress as well as inflammation. Moreover, it attenuated the raised neuronal injury score in a resistant model of epilepsy.

CONCLUSION

The modulation of the P-gp expression by Fingolimod improved drug delivery to the brain in an animal model of refractory epilepsy. Therefore, S1P signaling could serve as an additional therapeutic target to overcome refractoriness.

Oleanolic acid suppresses pentylenetetrazole-induced seizure in vivo

The aim of this study was to investigate the protective effects of triterpene oleanolic acid on the brain tissue of mice with pentylenetetrazole (PTZ)-induced epileptic seizures. Male Swiss albino mice were randomly separated into five groups as the PTZ, control, and oleanolic acid (10, 30, and 100 mg/kg) groups. PTZ injection was seen to cause significant seizures compared with the control group. Oleanolic acid significantly prolonged the latency to onset of myoclonic jerks and the duration of clonic convulsions, and decreased mean seizure scores following PTZ administration. Pretreatment with oleanolic acid also led to an increase in antioxidant enzyme activity (CAT and AChE) and levels (GSH and SOD) in the brain. The data obtained from this study support oleanolic acid may have anticonvulsant potential in PTZ-induced seizures, prevent oxidative stress and protect against cognitive disturbances. These results may provide useful information for the inclusion of oleanolic acid in epilepsy treatment.

Effect of digoxin, sodium valproate, and celecoxib on the cerebral cyclooxygenase pathway and neuron-specific enolase under the pentylenetetrazole-induced kindling in mice

Neuroinflammation plays an important role in the pathogenesis of epilepsy, so it is necessary to clarify the influence of standard antiepileptic drugs as well as adjuvant agents (e.g., cardiac glycoside digoxin, which previously showed a clear anticonvulsant potential) on cyclooxygenase pathway and neuron-specific enolase under the conditions of chronic epileptogenesis. The aim of the article is to determine the effect of digoxin, sodium valproate, and celecoxib per se, as well as the combination of digoxin with sodium valproate on the content of cyclooxygenase 1 and 2 types, prostaglandins E2, F2α, I2, thromboxane B2, 8-isoprostane and neuron-specific enolase in the brain of mice in the pentylenetetrazole-induced kindling model. It was found that only the combination of sodium valproate with digoxin provides a complete protective effect (absence of seizures) and shows the clearest influence on neuroinflammation markers and neuronal damage than monotherapy with each of these drugs and celecoxib, which appeared to be an ineffective anticonvulsant. The obtained results indicate that digoxin is a promising adjuvant drug to classical antiepileptic drugs (mostly sodium valproate) in epilepsy treatment.c.

Anti-kindling effect of Ginkgo biloba leaf extract and L-carnitine in the pentylenetetrazol model of epilepsy

Epilepsy is one of the most common serious brain disorders, affecting about 1% of the population all over the world. Ginkgo biloba extract (GbE) and L-carnitine (LC) reportedly possess the antioxidative activity and neuroprotective potential. In this report, we investigated the possible protective and therapeutic effects of GbE and LC against pentylenetetrazol (PTZ)-induced epileptic seizures in rat hippocampus and hypothalamus. Adult male albino rats were equally divided into eight groups: control, GbE (100 mg/kg), LC (300 mg/kg), PTZ (40 mg/kg), protective groups (GbE + PTZ and LC + PTZ), and therapeutic groups (PTZ + GbE and PTZ + LC). The oxidative stress, antioxidant, and neurochemical parameters, viz., malondialdehyde (MDA), nitric oxide (NO), reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), acetylcholine esterase (AchE), dopamine (DA), norepinephrine (NE), and serotonin (5-HT), in the hippocampal and hypothalamic regions have been evaluated. PTZ injection leads to an increase in the seizure score, the levels of MDA and NO, and to a decrease in the activity of GSH, SOD, CAT, and GPx. Besides, monoamine neurotransmitters, DA, NE, and 5-HT, were depleted in PTZ-kindled rats. Furthermore, PTZ administration caused a significant elevation in the activity of AchE. Hippocampal and hypothalamic sections from PTZ-treated animals were characterized by severe histopathological alterations and, intensely, increased the ezrin immunolabeled astrocytes. Pre- and post-treatment of PTZ rats with GbE and LC suppressed the kindling acquisition process and remarkably alleviated all the aforementioned PTZ-induced effects. GbE and LC have potent protective and therapeutic effects against PTZ-induced kindling seizures via the amelioration of oxidative/antioxidative imbalance, neuromodulatory, and antiepileptic actions.

The Influence of Palmatine Isolated from Berberis sibirica Radix on Pentylenetetrazole-Induced Seizures in Zebrafish

Palmatine (PALM) and berberine (BERB) are widely identified isoquinoline alkaloids among the representatives of the Berberidaceae botanical family. The antiseizure activity of BERB was shown previously in experimental epilepsy models. We assessed the effect of PALM in a pentylenetetrazole (PTZ)-induced seizure assay in zebrafish, with BERB as an active reference compound. Both alkaloids were isolated from the methanolic root extract of Berberis sibirica by counter-current chromatography, and their ability to cross the blood–brain barrier was determined via quantitative structure–activity relationship assay. PALM exerted antiseizure activity, as confirmed by electroencephalographic analysis, and decreased c-fos and bdnf levels in PTZ-treated larvae. In a behavioral assay, PALM dose-dependently decreased PTZ-induced hyperlocomotion. The combination of PALM and BERB in ED₁₆ doses revealed hyperadditive activity towards PTZ-induced hyperlocomotion. Notably, we have indicated that both alkaloids may exert their anticonvulsant activity through different mechanisms of action. Additionally, the combination of both alkaloids in a 1:2.17 ratio (PALM: BERB) mimicked the activity of the pure extract, which indicates that these two active compounds are responsible for its anticonvulsive activity. In conclusion, our study reveals for the first time the anticonvulsant activity of PALM and suggests the combination of PALM and BERB may have higher therapeutic value than separate usage of these compounds.

Extraction, GC-MS Evaluation and Anti-epileptic Potential of Seeds Ethanolic Extract of Putranjiva roxburghii Wall

BACKGROUND

Putranjiva roxburghii Wall is traditionally known to cure many pathological conditions including epilepsy.

OBJECTIVE

The present study is aimed at determining bioactive compounds in ethanolic extract of Putranjiva roxburghii test extract (PRTE) seeds by GCMS analysis and to assess its antiepileptic potential using various experimental models of epilepsy.

METHODS

The ethanolic extract of seeds of Putranjiva roxburghii was subjected to GC-MS analysis to detect the bioactive phytoconstituents. Acute oral toxicity of the extract was performed using OCED guideline 420. Pentylenetetrazol (PTZ) kindling model of epilepsy and Maximal electroshock epilepsy (MES) model of epilepsy were used to determine anti-epileptic potential.

RESULTS

The GC-MS analysis of the extract revealed the presence of 20 phytoconstituents. The major phytoconstituents included n-Propyl heptyl ether (25.25%), 5-Ethyl hydantoin (8%), octadec- 9-enoic acid (16.25%) and 1, 2-Benzene dicarboxylic acid (11.86%). The PRTE (50 mg/kg and 100 mg/kg) afforded a significant and dose-dependent protection against PTZ-induced kindling epilepsy and MES induced epilepsy (p<0.001 and p<0.01).

CONCLUSION

Based on the above findings, it is evident that Putranjiva roxburghii seeds contain biologically active compounds. It can also be concluded that the extract possesses anti-epileptic potential.

Pentylenetetrazole-Induced Kindling Mouse Model

Pentylenetetrazole (PTZ) is a GABA-A receptor antagonist. An intraperitoneal injection of PTZ into an animal induces an acute, severe seizure at a high dose, whereas sequential injections of a subconvulsive dose have been used for the development of chemical kindling, an epilepsy model. A single low-dose injection of PTZ induces a mild seizure without convulsion. However, repetitive low-dose injections of PTZ decrease the threshold to evoke a convulsive seizure. Finally, continuous low-dose administration of PTZ induces a severe tonic-clonic seizure. This method is simple and widely applicable to investigate the pathophysiology of epilepsy, which is defined as a chronic disease that involves repetitive seizures. This chemical kindling protocol causes repetitive seizures in animals. With this method, vulnerability to PTZ-mediated seizures or the degree of aggravation of epileptic seizures was estimated. These advantages have led to the use of this method for screening anti-epileptic drugs and epilepsy-related genes. In addition, this method has been used to investigate neuronal damage after epileptic seizures because the histological changes observed in the brains of epileptic patients also appear in the brains of chemical-kindled animals. Thus, this protocol is useful for conveniently producing animal models of epilepsy.

Modified Leptazol Convulsive Therapy

The use of chemically induced convulsive therapy introduced by Von Meduna in 1934 was followed by the introduction of electric convulsive therapy by Cerletti and Bini in 1937. The latter method is now of almost universal use. The main reasons for the change over were the elimination of the unpleasant aura experienced in connection with the leptazol fit and the fact that body accidents were said to be less frequent with E.C.T. There does not appear to be any evidence of greater therapeutic efficiency with E.C.T. Bini and Bazzi (1949) in summarizing statistics covering twelve thousand cases, found no difference in the remission rates in the two therapies. Dedichen (1946) indicated that the value of the two therapies in depressions was similar and Ross (1946) found this also for cases of acute excitements.

Anticonvulsant activity of Citrus aurantium blossom essential oil (neroli): involvment of the GABAergic system

Citrus aurantium L. blossoms are an important medicinal plant part in Iran and some other countries. It is used in traditional medicine as an antiseizure and anticonvulsant natural agent. Early in vitro research of the anticonvulsant activity of the blossom extracts were done but there has been no investigation focused on the blossom essential oil and its anticonvulsant activity. The anticonvulsant activity of the essential oil of C. aurantium blossoms (neroli) was investigated. The anticonvulsant activity of neroli was assessed in pentylenetetrazole (PTZ)-induced convulsion by i.v. and i.p. methods and maximal electroshock (MES) in mice, with diazepam as the standard drug. While mechanistic studies were conducted using flumazenil, a GABA A-benzodiazepine receptor complex site antagonist. Neroli produced protection against clonic by i.v adminiatration of PTZ at 20 and 40 mg/kg, compared with protection with benzodiazepine. The mean onset and percentage protection against convulsion in neroli-treated mice were reduced by flumazenil. Intraperitonaeal PTZ also decreased the latency of clonic seizure in the neroli (40 mg/kg) treated group. We also showed that neroli (20 and 40 mg/kg), exhibited inhibition of the tonic convulsion induced by MES and decreased the mortality rate. Neroli was analyzed by GC and GC-MS and twenty three constituents, representing 91.0 % of the chromatographical oil were identified. The major components of neroli were characterized as linalool (28.5%), linalyl acetate (19.6%), nerolidol (9.1%) E,E-farnesol (9.1%), α-terpineol (4.9%) and limonene (4.6%) which might be responsible for the anticonvulsant activity. The results suggest that neroli possesses biologically active constituent(s) that have anticonvulsant activity which supports the ethnomedicinal claims of the use of the plant in the management of seizure.

Anatomically dependent anticonvulsant properties of temporally-coded electrical stimulation

In the PTZ animal model of epilepsy, electrical stimulation applied to the amygdaloid complex may result in either pro-convulsive or anticonvulsant effect, depending on the temporal pattern used (i.e. periodic-PS and non-periodic-NPS electrical stimulation). Our hypothesis is that the anatomical target is a determinant factor for the differential effect of temporally-coded patterns on seizure outcome. The threshold dose of PTZ to elicit forelimb clonus and generalized tonic-clonic seizure behavior was measured. The effect of amygdaloid complex PS on forelimb clonus threshold showed a pro-convulsive effect while NPS was anticonvulsant. NPS also significantly increased generalized tonic-clonic threshold; while PS, although at lower threshold levels, did not present statistical significance. Thalamus stimulation did not affect forelimb clonus threshold and showed similar anticonvulsant profiles for both PS and NPS on generalized tonic-clonic threshold. In summary, the anatomical target is a determinant factor on whether temporally-coded ES differentially modulates seizure outcome.

The birth of convulsive therapy revisited: a reappraisal of László Meduna's first cohort of patients

BACKGROUND

The introduction of convulsive therapy (COT) was undoubtedly one of the milestones in the history of psychiatry. Its originator, László Meduna, has become one of the founding fathers of biological psychiatry.

METHODS

In his first major publication on COT, Meduna described the short-term treatment outcome of the first 26 schizophrenia patients who underwent camphor- or cardiazol-induced COT; 10 improved significantly, 3 appeared slightly improved, and 13 were unimproved. The original medical notes of 23 of the 26 patients were recently recovered and the patients re-diagnosed by the authors employing ICD-10 criteria.

RESULTS

The diagnosis of schizophrenia was confirmed in 15 cases (all but two of them involving prominent catatonic symptomatology), while 2 cases met diagnostic criteria for schizoaffective disorder, 3 for Bipolar Affective Disorder (BAD) with psychotic features, 1 for psychotic depression, and 1 for Acute and Transient Psychotic Disorder (ATPD). In a final case, the most probable diagnosis was schizophrenia. Scrutiny of the notes revealed that 4 schizophrenia patients evidenced slight improvement on COT and in one case the improvement was only transient. A limitation of this study is that the quality of the original files varied considerably and the re-evaluation was done retrospectively.

CONCLUSIONS

A very broad concept of schizophrenia in the 1930s explains the discrepancy between the original and the revised results. In line with the current views on the effectiveness of electroconvulsive therapy, catatonic symptoms, but not the core schizophrenic process, showed some improvement while all ATPD, BAD and depressed patients responded to COT.

Anticonvulsant activity of DNS II fraction in the acute seizure models

AIM OF THE STUDY

Delphinium nordhagenii belongs to family Ranunculaceae, it is widely found in tropical areas of Pakistan. Other species of Delphinium are reported as anticonvulsant and are traditionally used in the treatment of epilepsy. Delphinium nordhagenii is used by local healer in Pakistan but never used for scientific investigation as anticonvulsant. Thus, Delphinium nordhagenii was subjected to bioassay-guided fractionation and the most active fraction, i.e. DNS II acetone was chosen for further testing in the acute seizure models of epilepsy to study the antiepileptic potential in male mice.

MATERIALS AND METHODS

Different doses (60, 65 and 70mg/kg, i.p.) of DNS II acetone fraction of Delphinium nordhagenii was administered 30min prior the chemoconvulsant's injection in the male mice. Convulsive doses of chemoconvulsants (pentylenetetrazole 90mg/kg, s.c. and picrotoxin 3.15mg/kg, s.c.) were used. The mice were observed 45-90min for the presence of seizures. Moreover, four different doses of DNS II (60, 65, 70 and 100mg/kg, i.p.) were tested in the MES test.

RESULTS

The DNS II acetone fraction of Delphinium nordhagenii has exhibited the anticonvulsant actions by preventing the seizures against PTZ- and picrotoxin-induced seizure as well as 100% seizure protection in MES test. The results are comparable with standard AEDs (diazepam 7.5mg/kg, i.p. and phenytoin 20mg/kg, i.p.).

CONCLUSIONS

These findings suggest that the Delphinium nordhagenii possesses the anticonvulsant activity. Further analysis is needed to confirm the structure and target the extended activity profile.

'A violent thunderstorm': Cardiazol treatment in British mental hospitals

In the annals of psychiatric treatment, the advent of Cardiazol therapy has been afforded merely passing mention as a stepping-stone to the development of electroconvulsive therapy. Yet in the 1930s it was the most widely used of the major somatic treatment innovations in Britain's public mental hospitals, where its relative simplicity and safety gave it preference over the elaborate and hazardous insulin coma procedure. Devised on a dubious hypothesis of biological antagonism, Cardiazol armed psychiatry with an immediately effective weapon in the battle against schizophrenia, an enduring and debilitating condition responsible for over half of the mental hospital population. What made Cardiazol work - or appear to work? This account shows how evaluation of convulsive therapy was skewed by naive outcome measurement and diagnostic discrepancies, and how its therapeutic indication evolved from schizophrenia to affective disorders. Psychological mechanisms are considered, with the suggestion that the intense fear experienced during treatment--the major reason for abandoning Cardiazol in favour of electroshock--was therapeutically advantageous.

[Treatment of status epilepticus]

Status epilepticus (SE) is a condition requiring emergency care. There are convulsive SE, non-convulsive SE including complex partial status and absence status, non-convulsive electric SE and pseudostatus epilepticus, although convulsive SE is the most common. Diagnosis of status epilepticus of complex partial seizures (CPS) and absence seizures was significantly delayed because delays in seeking medical attention were common. The seizures were generalized convulsive SE in 84% and CPS status in 16%, and the overall mortality rate was 15% in 41 SE patients of our study. EEG monitoring is important to make or exclude the diagnosis of SE. Diazepam is the first choice medication and effective in the management of SE, and lately, lorazepam, midazolam, propofol and pentobarbital etc as emergency therapy. Phenytoin is also considered first-line agent in the emergency management of SE. Repetitive transcranial magnetic stimulation (rTMS) led to a prolonged latency for seizure induction after an intraperitoneal injection of pentylenetetrazol (PTZ) and effectively prevented the development of status epilepticus of PTZ-induced convulsions in the rats. Our data suggest that rTMS has suppressive effects on the neuronal excitability in rats. These effects are anticonvulsive and suggest the possibility of therapeutic use of rTMS in the patients with refractory seizures.

Long-term follow-up of patients with a diagnosis of paranoid state and hospitalized, 1913 to 1940

From a sample of 239 patients diagnosed paranoid state and hospitalized between 1913 and 1940 at the Phipps Clinic, we particularly studied a group of 60 patients without previous hospitalizations, consisting of 57 patients with follow-ups of 5 or more years, and 3 patients who killed themselves (the ultimate follow-up) less than 1 year after discharge. These 60 patients had been retrospectively diagnosed with delusional disorders by DSM-IV criteria. On follow-up, 27% were rated recovered, whereas 52% were rated unimproved. Long-term follow-up was correlated with discharge status. Poor follow-up was significantly correlated with seclusive personality, poor premorbid history, onset 6 months or more before admission, gradual onset, lack of insight, single marital status, and lack of precipitating events. A prognostic scale constructed from the first four of these variables was predictive of long-term outcome. More recent, better treatment results have been contrasted with these findings from an earlier non-drug-treatment era.

The early history of convulsive therapies in Australia

The early experience of convulsive therapies in Australia was reported in the Medical Journal of Australia from 1935 to 1950. Cardiazol convulsive therapy, first used in Australia in 1937, appears to have been widely employed. Electroconvulsive therapy, first used here in 1941, rapidly became accepted as a mainstream treatment. Early response rates are discussed, as well as Australian adaptations of European techniques. Clinicians of the day considered the use of these procedures carefully and were circumspect about their future role.

Clinical signs of ivermectin toxicity and the efficacy of antigabaergic convulsants as antidotes for ivermectin poisoning in epileptic chickens

The clinical signs of ivermectin toxicity were determined in 6 groups of 10 epileptic and 8 non-epileptic chickens for 72 h after dosing with sc injections of 5.0, 7.5, 10.0, 12.5 or 15.0 mg ivermectin/kg bw. At the 5.0 mg/kg dose, mild diarrhea developed 4 h post-dosing and lasted until the end of the 72-h monitoring period. With higher doses of ivermectin body weight, egg production and feed and water consumption were markedly reduced. Severe diarrhea, mydriasis, bradypnea, ataxia, sedation, coma and death occurred with the highest dose of ivermectin. No differences in the signs of ivermectin toxicity were observed between epileptic and non-epileptic chickens. To assess the efficacy of the antiGABAergic convulsants, methyl-beta carboline-carboxylate (beta-CCM), picrotoxin and pentylenetetrazol (PTZ), as antidotes for ivermectin toxicity, 8 epileptic and 6 non-epileptic chickens/treatment group were given dosages of each convulsant which previously induced convulsions in 50% (ED50) and again in 100% (ED100) of treated chickens. These convulsants were given 6 h after dosing with 15.0 mg ivermectin/kg. The ED100 dosages of picrotoxin and PTZ alleviated mydriasis and sedation, but did not reduce the diarrhea. The ED50 dose convulsants were not effective in reducing or alleviating ivermectin toxicity, nor was alleviation of any sign of ivermectin toxicity obtained with any dosage of beta-CCM. Although the dosages of these antiGABAergic convulsants used normally produced convulsions in epileptic and non-epileptic chickens, no convulsions were observed in chickens with ivermectin toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticonvulsant activity of phenytoin-lipid conjugates, a new class of phenytoin prodrugs

The anticonvulsant activity of phenytoin-lipid conjugates obtained by covalent binding of 3-hydroxy-methylphenytoin to dimyristoylglycerides via a succinidyl linkage, to 2-(1,3-dimyristoylglyceryl)butyric acid and to 3-myristoyl-2-myristoylmethylpropionic acid was evaluated in the maximal electroshock (MES) test and the seizure threshold test with subcutaneous pentetrazol. The phenytoin-lipid conjugates were less active than the parent drug in the MES test after intraperitoneal administration as suspensions, but exhibited comparable activity when injected as a solution in dimethylsulphoxide. They also protected mice from MES-induced seizures following oral administration of aqueous suspensions of the compounds or when incorporated into emulsions. The anticonvulsant activity could be correlated to in-vitro pancreatic lipase-mediated hydrolysis. The bis-deacyl derivatives were at least as active but in some cases also more toxic than phenytoin. Oral administration of two of the lipid conjugates resulted in a faster onset of the anticonvulsant activity compared with the administration of an equimolar dose of phenytoin itself. All compounds were inactive in the subcutaneous pentetrazol test. It is concluded that the lipids act as prodrugs of phenytoin, which is generated by lipolysis upon oral administration.

Effects of pharmacological manipulation of GABAergic neurotransmission in a new mutant hamster model of paroxysmal dystonia

Attacks of sustained dystonic postures of limbs and trunk can be initiated by handling or mild environmental stimuli (e.g. new cage) in an inbred line of Syrian hamsters. The severity of the dystonic syndrome in these mutant hamsters (gene symbol dtsz) is age-dependent, with a peak at about 30-40 days of age. A scoring system for grading type and severity of the dystonic attacks can be used to study the activity of drugs against dystonic movements with individual pre- and post-drug vehicle trials as control. In the present experiments, the effects of drugs which alter GABAergic functions in the brain were studied in dystonic hamsters. Anticonvulsants, i.e. valproate, diazepam and phenobarbital, which augment GABAergic neurotransmission, decreased the severity of dystonic attacks in the mutant hamsters, while administration of subconvulsive doses of pentylenetetrazol or the inverse benzodiazepine receptor agonist FG 7142 increased the severity of the syndrome. Anticonvulsants, i.e. phenytoin and carbamazepine, which are not thought to act via effects on GABAergic neurotransmission, exerted no antidystonic effects, but even worsened the attack in several animals. In contrast, the GABA-elevating drug, aminooxyacetic acid, produced a marked antidystonic effect in the hamsters. Similarly, the GABAB receptor agonist, baclofen, significant decreased the severity of the dystonic attack. The data indicate that dystonic movements in dtsz mutant hamsters can be attenuated by drugs which facilitate GABAergic functions, but worsened by drugs which impair GABAergic neurotransmission. These data thus seem to suggest that the dystonic syndrome in dtsz mutant hamsters is under GABAergic influence. The data show furthermore that dystonic hamsters are a suitable model to detect antidystonic effects of drugs.

Effects of flunarizine on Metrazol-induced seizures in developing rats

Antimetrazol action of flunarizine (5, 10, 20 and 40 mg/kg i.p.) was tested during ontogenesis on male Wistar rats aged 7, 12, 18, 25 and 90 days. The latencies and incidences of jerks, minimal Metrazol seizures and major Metrazol seizures remained unchanged by flunarizine in all age groups. A specific action (an abolition of the tonic phase of major seizures) was seen throughout the development and was reflected in lower scores of seizures.

Pharmacology of dementia

The authors discuss cerebral vasodilators, cerebral metabolic enhancers, nootropics, opioid antagonists, psychostimulants, cholinergic agents, and neuropeptides. Their efficacy in the treatment of dementing illnesses is evaluated.

Chemotherapy of cognitive disorders in geriatric subjects

Many of the neurochemical changes associated with aging brain, particularly lower choline acetyltransferase and higher monoamine oxidase, occur with greater severity in senile dementia, Alzheimer's type (SDAT). These alterations correlate with neuropathologic indices, e.g., the number of senile plaques and tangles. Although many different treatment techniques have been used, most have been unsuccessful. No strong data have supported the use of stimulants, Gerovital H3, or hyperbaric oxygen. Among the vasodilators, cyclandelate and hydergine may be of value in some but not most patients. Much recent work has focused on techniques to increase acetylcholine brain concentrations. To date, precursors, such as choline, seem to have very limited value. Postsynaptic treatments, e.g., physostigmine, hold more hope for future benefit, if longer acting oral preparations are developed. Other compounds, such as ACTH, vasopressin, and piracetam, may have some value but need better definition and treatment indications. Recent discoveries on the influences of lecithin on membrane fluidity and receptor binding, may affect the focus of future pharmacologic investigation.

Apneustic respiration normalized by an atypical cholinergic drug action in cats

Cats were anesthetized with a mixture of pentobarbital and barbital given intraperitoneally and vagotomized. All animals were pretreated with atropine i.v. which blocked conventional muscarinic receptors and at the same time revealed atropine-insensitive sites whose stimulation by the cholinergic drug, bethanechol, was earlier found to produce respiratory analepsis. Respiration was recorded by pneumotachograph and intrapleural cannula. Apneustic breathing was produced by placing electrolytic lesions in the pneumotaxic area or by injecting a local anesthetic agent into the cerebrospinal fluid. Experiments were performed under isocapnic conditions. Bethanechol, administered intracerebro-ventricularly, restored regular breathing and increased the tidal volume in a dose-related manner within minutes of its injection. In cats with lesions, the expiratory pause generally decreased first and was followed by shortening of the inspiratory plateau. In cats made apneustic by intracerebro-ventricular injection of procaine, bethanechol acted competitively to normalize the distorted waveshape. The central excitant drug pentylenetetrazol was given intravenously for comparison with bethanechol. Apneustic breathing was partially corrected by pentylenetetrazol through a facilitatory influence on the brain stem interpreted to be independent of its convulsant action. These experiments demonstrate correction of pathological breathing by two chemically unrelated agents which share the ability to increase central excitatory state.

Central-nervous-system stimulants: appraisal of use in geropsychiatric patients

CNS stimulants such as methylphenidate and pentylenetetrazol are currently prescribed for the treatment of aged persons with symptoms of senility. A review of clinical studies conducted with these compounds indicates that firm evidence of efficacy is lacking. Because of the risks associated with high doses of such stimulants in the aged, it would seem that these compounds are of limited utility in geriatric psychiatry.

The photically evoked afterdischarge: a model for the study of drugs useful in the treatment of petit mal epilepsy

Lightly restrained albino rats were administered dipropylacetic acid, trimethadione, diphenylhydantoin, saline, and a pentylenetetrazol challenge. The results were attributed to the locus of action of the anticonvulsants and strongly support the usefulness of the photically evoked after discharge as a model for the evaluation of thalamically active drugs, with particular reference to those useful in the control of petit mal epilepsy.

[Effect of various analeptics on the outcome of acute microwave lesion in mice]

The survival of albino mice irradiated by microwaves till the terminal state (wave length of 12.5 cm, intensity-62 +/- 5 microvat, for 14-16 minutes), given directly after irradiation diethylamide of nicotinic acid (cordiamine) in a dose of 50 mg/kg intraperitoneally and strychnine nitrate in a dose of 1 mg/kg, subcutaneously, i. e. nearly 1.5 times as much as received by controls, was studied. The application of caffeine sodium benzoate, camphor, metrasol, lobeline hydrochloride and cytisine, employed in different doses, proved to be little effective.

Benign paroxysmal positonal vertigo: A clinical study

Summary--Ru-Vert, a combination product, containing in each tablet, 25 mg of pentylenetetrazol, 12.5 mg of pheniramine maleate, and 50 mg of nictonic acid, was evaluated in the treatment of seventeen patients with benign paroxysmal positional vertigo. The study was double-blind with crossover. Ru-Vert at a dosage of two tablets t.i.d. was found to reduce significantly the nystagmus and the vertigo induced by Hallpike maneuvers in these patients.