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Biomedical subjects

E Varga

Publications and source records attributed to E Varga.

At least 109 records · Page 6Linked to original sources
PubMed1985

Comparing bilateral to unilateral electroconvulsive therapy in a randomized study with EEG monitoring.

In a double-blind study, 48 DSM-III depressed patients were randomly assigned to either the bilateral or nondominant unilateral electroconvulsive therapy (ECT) group. Seizure length was monitored by electroencephalography (EEG). When seizures were less than 25 s, ECT was immediately readministered. When length of seizure and pretreatment depression scores were controlled between the two groups, there were no differences in treatment effectiveness, as measured by the Hamilton Rating Scale for Depression and the Beck Depression Inventory, or in the number of treatments required. This was true after five ECT treatments as well as after completing all ECT treatments. Thus, when ECT is monitored via EEG to assure the presence of an adequate seizure, bilateral and nondominant unilateral placement yield equivalent responses. If ECT had not been readministered immediately following a missed seizure, unilateral patients would have had significantly more missed seizures. Significant difficulties in both short- and long-term memory were found 24 hours after the fifth ECT in bilateral but not in nondominant unilateral patients. No apparent memory loss could be documented in nondominant unilateral ECT.

Adult↗
PubMed1985

Cevadine-induced changes of membrane potential and sodium transport of muscle membrane in a chloride-free solution.

Cevadine-induced changes in membrane potential, sodium transport, intracellular Na, K, and water content were investigated in sartorius muscles incubated in chloride-free (glutamate) Ringer. Cevadine sensitivity of muscles incubated in glutamate Ringer was about five times greater than that of muscles incubated in normal Ringer. Therefore, even 0.005 mmol/l cevadine could induce depolarization and membrane potential oscillations. The membrane potential oscillations were recorded much longer from muscles incubated in chloride-free Ringer (even in the 15th hour of treatment) than in normal Ringer. Depolarization and membrane potential oscillations reversed more slowly in cevadine-free glutamate Ringer than in alkaloid-free normal Ringer. The rhythmic activity could be recorded even in the 10th-15th hour of incubation in cevadine-free glutamate Ringer. Cevadine increased the 24Na uptake of muscles incubated in glutamate Ringer by an average of 230%. In comparison, the cevadine-induced increase of 24Na uptake of muscles incubated in normal Ringer was approximately 350%. In the presence of cevadine the 24Na loss of muscles incubated either in glutamate or in normal Ringer increased to the same degree, i.e. three times. The increase of 24Na loss developed faster in glutamate Ringer than in the presence of chloride. The water content of muscles incubated in cevadine containing, chloride-free (glutamate) Ringer did not increase significantly. Muscles incubated in normal Ringer with cevadine showed a 42.7% increase of water content in 2 hours. Intracellular Na content and Na concentration increased by about 60% during a 2-hour-treatment with cevadine in a chloride-free environment. At the same time, cevadine treatment increased the intracellular Na content and Na concentration of muscles incubated in normal Ringer by about 160% and 80%, respectively. The cevadine-induced decrease of intracellular K content and concentration of muscles incubated in glutamate Ringer was 5% and 10%, respectively, in 2 hours. On the other hand, the decrease of intracellular K concentration in muscles incubated in cevadine-containing normal Ringer occasionally reached 30% due to the increase of water content of the muscles. The cevadine-induced increase of the wet weight of muscles incubated in normal Ringer was practically irreversible. It was not possible to eliminate the increase of wet weight even by washout lasting for 10-15 hours.

Animals↗
PubMed1985

Effect of phlorizin on the changes of membrane potential, water, Na and K transport induced by cevadine in frog muscle.

The effect of phlorizin on the parameters of cevadine induced membrane potential oscillation and the development of the potential changes were investigated in frog (Rana esculenta) sartorius muscles. The action of phlorizin on Na transport, water and cation contents of cevadine-treated muscles were also studied. On the effect of phlorizin applied at a concentration of 1 mmol/1 the frequency of the membrane potential oscillation evoked by cevadine decreased by about half, parallel with an about four-fold increase in the duration of the resting period and the prepotential. Phlorizin, applied at a concentration of 2 mmol/l on the neural part of the muscle before cevadine treatment, delayed the development of depolarization evoked by cevadine. In the cevadine-pretreated muscles the enhanced 24Na-uptake was not reduced by 2 mmol/l phlorizin. 2 mmol/l phlorizin, applied during the radioactivity washout period, diminished reversibly the rate coefficient for 24Na loss by 49% in 120 min. The 24Na-efflux increasing effect of cevadine, which is characteristic otherwise, was prevented by phlorizin. This action was also reversible. The intracellular water, Na, and K contents of muscles were not altered significantly by 2 mmol/l phlorizin even in 3 hours. Under the effect of cevadine the characteristic gain in intracellular water, Na content and [Na]i developed despite phlorizin treatment, but the changes mentioned above evolved more slowly. In the phlorizin-pretreated muscles the K-content decreasing effect of cevadine failed to come about. In the muscles pretreated with phlorizin the [K]i was reduced by cevadine at a proportional degree to water-uptake.

Animals↗
PubMed1984

Dexamethasone in electroconvulsive therapy: efficacy for depression and post-ECT amnesia.

Dexamethasone, compared to placebo in a double-blind study, failed to prevent the memory deficiency that typically accompanies electroconvulsive therapy (ECT) (n = 48 patients treated for DSM-III diagnosed major depressive disorder). Rather, the administration of the drug was associated with attention (p less than 0.02) and short-term memory (p less than 0.0003) difficulties in both bilateral and unilateral ECT patients. Bilateral ECT plus dexamethasone patients had significantly less improvement (p less than 0.05) in their depression (measured by the Hamilton Depression Scale) compared to bilateral ECT plus placebo patients. These depression differences were not seen among unilateral ECT patients.

Amnesia↗
PubMed1982

The effect of codeine on involutional and senile depression.

The authors studied the effect of codeine on 12 severely depressed patients who failed to respond to tricyclic antidepressants. They all were in involution. Eight patients received codeine in combination with other tricyclic antidepressants and only one of them showed improvement. Four depressed patients received codeine alone and none of them improved. The patients were kept on codeine up to three weeks. The dose was gradually increased from 90 mg/day to 180 mg/day. All patients suffered from severe constipation--more than what they had on tricyclic antidepressant medication. All of the patients experienced a sedative effect. None of them had euphoria and none of them developed dependence. After the failure of codeine, the patients finally accepted electroconvulsive therapy or monoamine oxidase inhibitors, and with one exception, all improved.

Aged↗
PubMed1981

Membrane potential dependence of potential oscillation induced by cevadine in striated muscle.

The dependence of the membrane potential oscillation induced by cevadine on the actual transmembrane potential was studied in the frog sartorius muscle. 1. If the membrane potential oscillation is recorded for hours, its amplitude is seen to decrease slowly and smoothly and the membrane potential measured during the resting period among the waves of oscillation also decreases simultaneously. This means that the depolarization increases. 2. The increase of depolarization results not only in a decrease in the amplitude of the oscillation but the oscillation ceases between -40 and -55 mV as well. 3. The phenomenon reappears if the membrane is partially repolarized on a cevadine treated muscle fibre on which the membrane potential oscillation has already ceased as a consequence of the relatively marked depolarization. 4. Changing the membrane potential either to a value more positive than -40 mV, or to one more negative than -90 mV the developed oscillation activity may reversibly be suspended. 5. According to the above results, the amplitude of the membrane potential oscillation depends on the actual membrane potential. If other factors which may influence the oscillation parameters are unchanged, the relationship between the oscillation amplitude and the membrane potential can be characterized by a linear equation. In these cases there is a close correlation between the measured values and the calculated ones.

Animals↗
PubMed1981

Hemoperfusion for chronic schizophrenia: preliminary psychiatric results.

Six patients with chronic schizophrenia unresponsive to accepted therapy were assigned randomly to receive as adjunctive therapy either (A) weekly coated-charcoal hemoperfusion (CCHP) or (B) sham hemoperfusion (Sham HP) in a double-blind study using two independent psychiatric raters. Four weeks of treatment suggested that (1) CCHP was associated with significant improvement in some psychiatric measures, (2) improvement was early in the treatment course, and (3) neither CCHP nor Sham-HP was associated with deterioration in any of the psychiatric measures. When one patient from each group was "crossed-over" to receive the opposite treatment these conclusions were supported. Further studies appear to be warranted.

Chronic Disease↗
PubMed1980

Sodium dependence of membrane potential oscillation induced by veratrine.

The dependence of the membrane potential oscillation on extracellular sodium concentration was studied in the frog sartorius muscle. (1) When Na concentration of the Ringer solution was decreased to zero, the membrane potential oscillation cesed and the membrane tended to repolarize. This inhibitory effect was reversible. (2) Tetrodotoxin, 10(-7) g/ml, inhibited the development of membrane potential oscillation or stopped within 2--4 min the membrane potential oscillation already developed, the membrane then became partly repolarized maximum to -72mV. The inhibitory effect of tetrodotoxin was also reversible. (3) When the Na concentration of the Ringer solution was reduced to 60 mM the latency time of the membrane potential oscillation did not change. By further decreasing the Na concentration the latency time increased in a hyperbolic function. In case of 10 mM Na the latency period was 7 times longer than the control. (4) The depolarizing effect of veratrine was linearly related to the logarithm of Na concentration in a range from 10 to 120 mM Na. (5). By decreasing the [Na]c from 120 to 10 mM the frequency of oscillation decreased and the amplitude increased linearly as a function of the logarithm of Na concentration.

Animals↗
PubMed1980

Analysis of the sensitizing effect of veratrum alkaloids to potassium on frog muscle.

1. The sensitizing effect of veratrum alkaloids to potassium is not specific. Reducing the concentration of chloride in Ringer's solution, or treating the muscle with nicotine in a concentration close to threshold after pretreatment with subliminal concentration of cevadine result in a marked mechanical response of the muscle. However, cevadine does not alter the sensitivity of the muscle to caffeine. On the basis of these observations it has been suggested that veratrum alkaloids sensitize the muscle membrane essentially to depolarizing processes. 2. Cevadine, 0.01 mM, fails to depolarize the muscle membrane but increases the depolarizing effect of 10 mM potassium. The depolarizing effect of a reduction of the concentration of chloride from 120 mM to 30 mM is also increased in cevadine pretreated muscle. Cevadine pretreatment increases the depolarizing effect of nicotine, too. 3. The above sensitizing effects are unanimously Na-dependent. Accordingly there is no mechanical response and increased depolarization in muscles equilibrated in sodium-free (choline) Ringer's solution before the cevadine treatment. 4. On the basis of the present data it is suggested that the membrane, when sensitized by veratrum alkaloids, can be triggered by different depolarizing processes and the depolarization increases as the result of increased Na permeability. The increased depolarization at the threshold level becomes sufficient for the automatic regenerative processes of the action potential to develop which activate the contractile elements. However, the mechanical response is a prolonged contraction rather than a contracture, its long period being the result of a very slow repolarization caused by the well-known inhibitory effect of veratrum alkaloids on Na inactivation.

Animals↗
PubMed1980

Diagnosis of malignant tumors on the basis of the current generating capacity of malignant tumorous tissue. II. Study of the malignant tumors of female genital organs.

Description of an electrochemical measuring method for the in vivo quick-diagnosis of malignant tumors and dysplastic alterations of the cervical epithelium is given. The measuring results carried out in 660 cases on the surface of the cervical epithelium are reported. The current generating capacity of planocellular carcinoma of the cervical epithelium exceeds the upper limit of the normal value with 40% and is significantly higher than the values measured in dysplastic areas. With the aid of measuring, dysplastic alteration are demonstrable even in cases, in which the cytologic or coloposcopic examination is not indicative of dysplasia. Measurings in the benign and malignant tumorous tissue were carried out with needle electrode in 41 cases, during operation. The current generating capacity of malignant tumors exceeded with 150--170% the values measured in the healthy tissue, respectively in benign tumorous alterations.

Cervix Mucus↗