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Biomedical subjects

I Yaar

Publications and source records attributed to I Yaar.

At least 37 records · Page 2Linked to original sources
PubMed1980

Long-term cerebral effects of small doses of x-irradiation in childhood as manifested in adult visual evoked responses.

In Israel between the years 1949 and 1960, approximately 20,000 children ranging from 1 to 15 years of age were irradiated for eradication of tinea capitis. Radiation to the cerebral hemipheres ranged up to 140 rads. Of those treated, now adults, 44 subjects were elected by stratified sampling for recording and analysis of visual evoked responses (VERs). A control group of 57 subjects similar in age and ethnic origin was chosen. Two occipital leads, a right and a left, were recorded by the international 10-20 system. Fifty responses to diffuse white-flash stimulation were averaged in each case. The first 256 msec (data points) of each VER were reduced to 77 variables by repeated averaging over three adjacent data points; these variables were then analyzed by several statistical methods. The analyses detected significant differences between the VER averages in study subjects compared with controls. These differences may reflect delayed, probably permanent functional damage to the central nervous system caused by small doses of x-radiation (XR) to immature normal human brain. The left hemispheres appeared to be more involved, consistent with the fact that these children received, on the average, more XR to the left side of the brain, as shown in simulated phantom models. This disparity is reflected in a greater degree of difference between the left VERs of the irradiated versus control group. The major differences between the VERs occurred in the first part of the secondary response and suggest possible subcortical involvement. The results strengthen previous evidence of potential hazards of XR in children.

Adult↗
PubMed1980

The effect of levodopa treatment on the visual evoked potentials in Parkinsonian patients.

There is extensive literature on the effects of levodopa treatment on the visual evoked potentials (VEP) in laboratory animals and in depressed patients. The effects of levodopa on the VEP of parkinsonian patients were overlooked to a certain extent. In this work we searched for levodopa effects on the VEP of 42 parkinsonian patients. The VEP were data-reduced and analyzed by several techniques: (a) 256 data values (256 msec) were reduced to 70 variables by averaging; (b) time-domain parametric extraction: latencies to peak-and-trough points, amplitudes, etc., resulted in 14 variables; (c) frequency transformation into power spectral density bands resulted in 14 variables. Each one of the above variables was univariate, paired t-tested for levodopa effects. The overall effects of levodopa on the power variables and the time-domain parameters were evaluated by Hotelling paired T2. The 70 time variables were further reduced by the tolerance function of the discriminant procedure and analyzed both by direct and by stepwise discriminant analyses and by SAS-MANOVA in a pairwise design. Only few sporadic univariate t values reached significance levels. No overall multivariate significant effects of levodopa were found. In view of known dopaminergic involvement in parts of the visual system it is postulated that levodopa might have antagonizing effects at different levels of the visual pathways. This hypothesis and better understanding of levodopa effects on the visual system should probably be achieved by recording VEP from the visual subsystems.

Evoked Potentials↗
PubMed1979

Intracerebral tumor and diffuse central nervous system infiltration complicating acute myelogenous leukemia.

An intracerebral space occupying lesion was found in a 20-year-old woman with acute myelogenous leukemia (AML) when she was in complete hematological remission. Computerized tomography of the brain demonstrated the tumor in the roof of the third ventricle and its subsequent resolution after cranial irradiation and intraventricular cytosine-arabinoside. This form of central nervous system complication in AML has not been previously reported.

Adult↗
PubMed1979

[Motor-conduction velocity of cubital nerves in patients with leprosy reactions. Summary of a 13-year observation series during thalidomide therapy].

The motor conduction velocity of the ulnar nerves was examined repeatedly in 34 patients with lepromatous leprosy. In patients with active lesions the reduction in velocity paralleled clinical deterioration. In "burned-out" control patients, who had never suffered from leprosy reaction, the conduction velocity remained slow and unchanged over many years. Twenty-six of 34 patients suffering from leprosy reaction received Thalidomide treatment over a period of 6-13 years in order to suppress the reaction, with good effect. In none of these 26 patients neurotoxic disturbances were found.

Adult↗
PubMed1977

Aseptic meningitis: frequency among Israeli ethnic groups.

The relative frequency of aseptic meningoencephalitis (AME) was compared in populations of diverse origin, A countrywide search of Israel during 1969-1970 disclosed 1350 cases who fit strict diagnostic criteria. The average annual incidence was 21.6 per 100000 population. The total incidence was similar in Afro-Asian, Euro-American and Israeli Jewish groups but among Israeli Arabs, the incidence was apparently lower. Age-specific incidence showed a peak in infants under one year of age among Arabs and Afro-Asian Jews whereas Euro-Americans and Israeli Jews had a peak incidence at 5-9 years. Larger family size among Arabs and Afro-Asian Jews might account for the higher incidence in infants. Age-specific incidence may be a better index than total incidence of important differences in AME among various ethnic groups.

Adolescent↗
PubMed1977

EEG power spectral changes secondary to L-DOPA treatment in parkinsonian patients: a pilot study.

Clinical EEG evaluation and power spectral analysis were performed on 12 parkinsonian patients before and during L-DOPA treatment. The EEG evaluation did not disclose any significant effects of L-DOPA treatment. Spectral analysis disclosed normal interlobar and interhemispheric power differences and an increase in delta and slow-theta power in the right temporal as compared to the right occipital lobe before L-DOPA treatment was initiated. L-DOPA treatment significantly increased alpha power in both occipital lobes, decreased theta power in the right temporal lobe, accentuated power differences in the theta and alpha bands between temporal and occipital lobes and attenuated beta power differences in those areas. This work is intended as a pilot study in the quantitative EEG evaluation of Parkinson's disease and L-DOPA treatment.

Electroencephalography↗
PubMed1977

Paroxysmal choreoathetosis as a presenting symptom in idiopathic hypoparathyroidism.

A patient with idiopathic hypoparathyroidism presenting with spells of paroxysmal choreoathetosis is described. The possible mechanisms by which hypoparathyroidism induces choreoathetosis and other extrapyramidal motor dyfunctions are discussed. The need for screening patients with extrapyramidal disease for hypoparathyroidism is stressed.

Adolescent↗
PubMed1975

Passive transfer of experimental autoimmune myasthenia by lymph node cells in inbred guinea pigs.

Passive transfer of experimental autoimmune myasthenia (EAM) was performed with lymph node cells from donor guinea pigs immunized with purified acetylcholine receptor (AChR) from Torpedo californica. Recipient animals revealed the same clinical signs and electromyographic patterns as observed in actively challenged animals. These phenomena are parallel to the clinical manifestations of the human disease myasthenia gravis, in which cellular response to AChR was recently demonstrated.

Acetylcholine↗