Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

From the following three lines of evidence, it is proposed that at least part of the convulsant activity of naloxone is a result of GABA receptor blockade. Firstly, iontophoretic naloxone reversibly antagonized GABA-evoked depression of firing rate in 21 of 27 neurons tested in the rat olfactory tubercle-nucleus accumbens region, without blocking inhibition evoked in the same cells by glycine (15 cells) or morphine (6 cells). Secondly, i.p. naloxone in high doses caused convulsions in mice, and potentiated the convulsant activity of bicuculline, but not that of strychnine. Diazepam, which protected mice against convulsions elicited by bicuculline, but not by strychnine, also protected mice against naloxone. Thirdly, naloxone, morphine, levorphanol and its non-analgesic enantiomer dextrorphan displaced 3H-GABA from GABA receptor sites in homogenates of human cerebellum, all with comparable low potencies (IC50 = 250--400 micron). There was no correlation with affinities at the stereospecific receptor sites that mediate opiate-induced analgesia, since the potent opiates etorphine and diprenorphine were relatively inactive (IC50 greater than 3 mM). In addition naloxone displaced 3H-GABA from receptor sites in rate forebrain and cerebellum, with similar low potency.
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PMID:Naloxone as a GABA antagonist: evidence from iontophoretic, receptor binding and convulsant studies. 61 28

The intracranial, liquid-containing cysts in children (excluding tumor and parasitic cysts) are relatively frequent in neurosurgical practice. They raise several problems about their nosology, etiology, clinical and radiological diagnosis, and treatment which are analyzed in a series of 36 cases of supratentorial cysts. The most frequent clinical feature is increased head circumference (22 cases) followed by epileptic fits (18 cases), as well as mental and motor retardation (19 cases). Fundi were found abnormal in only one case out of three. Electroencephalogram was abnormal in almost every case, showing either spikes, spikes and waves or localized slow waves, or an asymmetric depression of the electrical activity. Radiological investigation is essential for diagnosis. Plain radiographs of the skull may show an asymmetry (11 cases). Carotid angiogram and pneumoencephalography give the diagnosis of the lesion without accuracy as to the histology. Computerized axial tomography shows the position of the liquid cavity within the head. The surgical approach (simple shunting [6], direct approach [19], or both [7]) should be carefully considered according to anatomical variety and age of the child. An anatomical classification is proposed, based on the radiological, surgical and pathological findings. Three types of cysts are defined: external cysts (cortical or extracortical) which may or may not be communicating with the ventrioles or the subarachnoid space; internal cysts which again may or may not be communicating; and the corticoventricular cysts. The ultrastructural study represents further progress in the attempt to define the exact anatomical type.
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PMID:Intracranial supratentorial cysts in children excluding tumor and parasitic cysts. 62 Jun 17

Verminous encephalitis in a 4-week-old kitten was manifested by depression, hysteria, and terminal convulsions. Necropsy revealed a second instar of Cutebra sp in the right cerebral hemisphere. The main lesions in the brain were those of acute focal hemorrhagic encephalomalacia.
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PMID:Intracerebral migration of Cuterebra larva in a kitten. 62 16

1 Rats were convulsed once daily for 7 days by exposure to the inhalant convulsant agent, flurothyl (Indoklon, bis (2,2,2-trifluouroethyl)ether). Twenty four hours after the final convulsion the rats were injected with tranylcypromine (20 mg/kg) followed 30 min later by L-DOPA (50 mg/kg), a procedure which increases brain dopamine concentrations. The flurothyl-treated rats showed a greater locomotor activity response than rats that had not been convulsed.2 This enhanced response appears to be due to increased postsynaptic dopamine receptor sensitivity since flurothyl-treated rats also showed enhanced locomotor responses to methamphetamine (2 mg/kg) and apomorphine (2 mg/kg).3 Enhanced 5-hydroxytryptamine-induced activity responses following administration of tranylcypromine (20 mg/kg) and L-tryptophan (50 mg/kg) were also seen 24 h after the last of 10 daily flurothyl-induced convulsions.4 The increased 5-hydroxytryptamine response also appears to be due to increased postsynaptic sensitivity since the flurothyl-treated rats showed increased hyperactivity following administration of tranylcypromine (20 mg/kg) and the suggested 5-hydroxytryptamine agonist, 5-methoxy N,N-dimethyltryptamine (2 mg/kg).5 No change in the brain concentration of 5-hydroxytryptamine, 5-hydroxyindoleacetic acid, tryptophan, dopamine or noradrenaline was observed 24 h after the last of 10 daily flurothyl-induced convulsions, compared to untreated rats. The rate of 5-hydroxytryptamine accumulation after tranylcypromine/L-tryptophan treatment and of dopamine and noradrenaline accumulation after tranylcypromine/L-DOPA treatment was similar in both groups.6 Repeated flurothyl convulsion has the same effects on these behavioural tests as repeated electroconvulsive shock. Since both treatments have been used successfully to treat depression, it is suggested that the mechanism of action of electroconvulsive therapy may be by increasing postsynaptic responses to the monoamine neurotransmitters.
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PMID:Repeated exposure of rats to the convulsant agent flurothyl enhances 5-hydroxytryptamine- and dopamine-mediated behavioural responses. 63 11

Verruculogen (V) and penitrem A (PA) represent a group of toxic secondary metabolites of mold contaminants of foodstuffs known as 'tremorgenic mycotoxins', which produce a unique neurotoxic syndrome characterized by sustained tremors, limb weakness, ataxia and convulsions. In the present study the intraperitoneal median tremogenic dose in mice for V was found to be 0.92 mg/kg and that for PA, 0.19 mg/kg. Behavioral and neurochemical parameters were assessed following acute exposure to varying neurotoxic and subneurotoxic doses of these mycotoxins. Measures of spontaneous motor activity (photoactometer) and exploratory reflex behaviors (open field) were markedly depressed by both V and PA. Notably, at dose levels of V or PA that were not accompanied by any overt signs of neurotoxicity, significant neuromotor depression was still observed. Acquisition of a conditioned avoidance shuttle response was disrupted, but only at a high neurotoxic dose level of V. Neurochemical analyses revealed no clear catecholaminergic or cholinergic involvement in the neurotoxic syndrome of eigher V or PA.
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PMID:Neurobehavioral studies of tremorgenic mycotoxins verruculogen and penitrem A. 64 98

Hypocalcemia, although a relatively uncommon sequela of operations for carcinoma of the larynx and pharynx, often presents as an acute medical emergency. In its chronic form, hypocalcemia may be a difficult disorder to control. Understanding the etiologic basis of hypocalcemia secondary to operations for carcinoma of the head and neck requires knowledge of the pathophysiology of the preoperative and postoperative factors affecting calcium homeostasis. These factors include thyroidectomy, hypoparathyroidism, hypomagnesemia, anticonvulsant therapy, estrogen replacement therapy, oral contraceptives, blood transfusions, hyperventilation alkalosis, hypoalbuminemia, corticosteroid therapy, depression, emotional stress and diet. Often the onset of symptoms and signs of hypocalcemia occurs within 24 to 48 hours after the operation. The symptoms may include mental depression, headache, tingling of the hands and perioral region and abdominal pain. Unrecognized chronic hypocalcemia may lead to the development of cataracts, convulsions and psychosis.
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PMID:Etiologic factors in hypocalcemia secondary to operations for carcinoma of the pharynx and larynx. 67 61

Diazepam 0.05-0.25 mg/kg increased the dose of lignocaine required to cause seizures in Rhesus monkeys by 24-34%. Spontaneous ventilation was maintained adequately during lignocaine administration following diazepam treatment and no adverse cardiovascular effects occurred. Before the onset of lignocaine-induced seizures in non-treated animals, the animals appeared to be drowsy. However, prior to administration of diazepam masked this effect. Convulsions were controlled by smaller doses of diazepam in non-treated animals than in diazepam-treated animals. Also, the animals that were pretreated with diazepam had a greater duration of depression after seizure.
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PMID:Diazepam in the prophylaxis of lignocaine seizures. 81 22

The effects of atropine, doxapram and isoproterenol upon soman-induced respiratory depression were investigated in the monkey. Administration of atropine resulted in an immediate increase in heart rate accompanied by a gradual increase in respiratory rate. The improvement in the EEG pattern coincided with improvement in respiratory function. Administration of either doxapram or isoproterenal during soman-induced apnea failed to significantly alter any of the physiological parameters. Clonazepam was used to control soman-induced seizure activity and convulsions.
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PMID:Effect of atropine upon the cardiovascular system during soman-induced respiratory depression. 82 8

The interactions of phenobarbital, barbital, and pentobarbital with high pressures of heliox were explored. Principal features of the complex results include: double peaks in the time course of convulsion thresholds (Pc); an early peak and a shoulder in the time course of pressures reversing anesthesia (Pa); far steeper dose-response curves for Pa than for Pc; selectively greater anticonvulsant effect for phenobarbital than for the other barbiturates; and enhancement of Pa with simultaneous depression of Pc by reserpine in phenobarbital-pretreated mice. The data indicate the existence of at least two discrete sites of interaction between barbiturates and high pressure, reflected by Pc and Pa. The implications of the data for the development of biophysical theories of pressure reversal of anesthesia and anti-high-pressure neurological syndrome action of anesthetics are discussed, together with implications for the experimental study of convulsant and anticonvulsant agents, and their applications to underwater physiology.
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PMID:Interaction of central nervous system effects of high pressures with barbiturates. 89 76

The author discusses the myths of the ECT process--that shock and the convulsion are essential, memory loss and brain damage are inescapable, and little is known of the process--and assesses the fallacies in these ideas. Present views of the ECT process suggest that its mode of action in depression may best be described as a prolonged form of diencephalic stimulation, particularly useful to affect the hypothalamic dysfunctions that characterize depressive illness. The author emphasizes the need for further study of this treatment modality and for self-regulation by the profession.
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PMID:Myths of "shock therapy". 90 Mar 9


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