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Biomedical subjects

V Nohria

Publications and source records attributed to V Nohria.

30 records · Page 2Linked to original sources

Climbing behaviour induced by apomorphine in mice: a potential model for the detection of neuroleptic activity.

Apomorphine and the putative dopamine agonist, 2-(N, N-dipropyl)-amino-5, 6-dihydroxytetralin induced dose-dependent climbing behaviour in the mouse which was measured in wire mesh lined cages as the percentage of time spent climbing in the 30 min period following the first climb and as the maximum time spent in a single climb throughout the drug effect. These These two measures were generally found to parallel excepting when the interacting agent caused muscular hypotonia. All potential interacting agents were given as pretreatments to determine changes in motor function which may interfere with the climbing induced by 1.0 mg/kg s.c. apomorphine. The possibility of a change in the apomorphine response to a sterotyped biting, which would also interfere with climbing, was also considered. Excluding these non-specific changes, climbing behaviour was shown to be antagonised, dose-dependently, by low doses of typical and atypical neuroleptic agents (haloperidol, fluphenazine, loxapine, pimozide, oxiperomide, clozapin, thioridazine, sulpiride, tiapride and metoclopramide) but not specifically by other psychoactive agents. Climbing behaviour was modified by serotonergic agents; the agonist quipazine reduced or abolished, whilst the antagonists, methysergide and cyproheptadine, enhanced the response. Picrotoxin specifically reduced climbing behaviour but sodium valproate exerted non-specific effects, precluding conclusions as to a GABA involvement. Cholinergic and noradrenergic involvements with climbing were also apparently eliminated by the ineffectiveness of atropine, aceperone, piperoxan and propranolol. The involvement of serotonin with climbing was extended to the actions of the neuroleptics: the antagonistic effects of typical neuroleptics (haloperidol, fluphenazine, loxapine) were markedly enhanced by combination with methysergide or cyproheptadine whilst the effects of clozapine, sulpiride and thioridazine were significantly reduced. The actions of metoclopramide, oxiperomide, pimozide and tiapride were not generally modified by such combinations. These differences are discussed in terms of differential abilities to induce extrapyramidal disturbances and the mouse climbing model is forwarded as a test with potential to detect antipsychotic agents of different activity spectra.

Animals↗

EKG abnormalities in pediatric patients with myotonic dystrophy.

Electrocardiographic (EKG) abnormalities are frequent in patients with myotonic dystrophy; cardiac complications may lead to significant morbidity and mortality. The charts of 17 pediatric patients with myotonic dystrophy were reviewed to ascertain the frequency of EKG abnormalities and cardiovascular symptoms. Fifteen of 17 patients had abnormal EKGs with sinus bradycardia being the most common abnormality. Only 1 of 17 patients had cardiovascular symptoms. Four patients had moderate to severe weakness and 3 of them had a conduction disturbance (i.e., first-degree AV block or intraventricular conduction delay). Two of the remaining 13 patients with mild weakness had conduction disturbances. No pediatric patients had progressive EKG abnormalities during follow-up. Baseline EKG study of pediatric patients with myotonic dystrophy is recommended because abnormalities are frequent and usually asymptomatic. Frequent follow-up EKGs are probably unnecessary unless the patient is symptomatic or has heart block.

Adolescent↗

Magnetic resonance imaging evidence of hippocampal sclerosis in progression: a case report.

A 32-month-old child presented in status epilepticus (SE) involving the left side of the body. Fast spin-echo magnetic resonance imaging (FSE-MRI) with hippocampal volumetry performed < or = 24 h after the seizure showed increased T2 signal of the right hippocampus, but no atrophy. Complex partial seizures (CPS) appeared at age 33 months, and three more episodes of SE occurred between 33 and 37 months of age. Follow-up FSE-MRI at 34 and at 45 months of age demonstrated progressive hippocampal atrophy with resolution of the increased T2 signal. Her CPS became intractable and, at age 51 months, she underwent right temporal lobectomy. In the ensuing 5 months, she has had only one major motor seizure. This case demonstrates that acute increased hippocampal T2 signal intensity can occur soon after SE and hippocampal sclerosis (HS) may become evident within months in the setting of recurrent early childhood SE. This observation may support the hypothesis that early childhood SE can lead to HS. Furthermore, this case suggests that years of temporal lobe CPS may not be necessary for development of HS.

Brain Diseases↗

Chiari I malformation: a review of 43 patients.

We have reviewed the presentation, diagnosis, management, and outcome of 43 consecutive patients with the Chiari I malformation who were evaluated over a 12-year period and were managed by a single surgeon. The delay from the time of presentation to that of diagnosis was significantly less in the pediatric group when compared to the adult group. Also, the delay in diagnosis before 1985 was significantly longer than after 1985, the year magnetic resonance imaging became widely available in clinical practice. We were able to show the patients who did not have hydrosyringomyelia were unlikely to develop scoliosis. Surgery resulted in overall improvement in both symptoms and signs, but the improvement in symptoms was more marked than the improvement in signs. There was positive correlation between improvement in hydrosyringomyelia and the improvement in signs and symptoms. Surgery was associated with no significant permanent injury as a result of the procedure in any of the patients. The effect of Chiari surgery on scoliosis was inconclusive.

Adolescent↗