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Biomedical subjects

E Kaplan

Publications and source records attributed to E Kaplan.

At least 163 records · Page 9Linked to original sources
PubMed1986

Depression influences intellectual impairment in stroke patients.

Patients with ischaemic lesions of the left cerebral hemisphere were examined for depression and intellectual impairment: in non-depressed patients, the severity of impairment was related to both lesion volume and location, as assessed by CT scan analysis. Cognitive impairment in patients with major depression was greater than predicted by lesion volume alone, and when patients were matched for severity of impairment, depressed patients had smaller lesion volumes than the non-depressed. After six months, non-depressed patients had significantly less cognitive impairment than depressed patients who showed no improvement. Both depression and lesion volume were significantly and independently related to cognitive impairment. These findings suggest that post-stroke depression can produce a true dementia in its own right, and that treatment of post-stroke depression might benefit cognitive function.

Adult↗
PubMed1985

High-performance liquid chromatography as a tool for identification of linolenic acid hydroperoxide prepared with soybean lipoxygenase.

Linolenic acid hydroperoxide, enzymatically produced by soybean lipoxygenase from linolenic acid, was purified by high-performance liquid chromatography (HPLC) using a Supelco LC-8 (5 microns), 22 cm X 4.6 mm I.D. column with a solvent system of acetonitrile-tetrahydrofuran-0.1% phosphoric acid (50.4:21.6:28, v/v/v). The hydroperoxide was converted to several derivatives, the hydroxy, methyl, and stearate which were analyzed by HPLC and identified by gas chromatography-mass spectrometry. The 13-hydroperoxy linolenic acid was the major hydroperoxide produced by soybean lipoxygenase.

Chromatography, High Pressure Liquid↗
PubMed1985

A phase II study of high-dose estrogens (diethylstilbestrol diphosphate) in prostate cancer.

Twenty-five patients with metastatic prostate cancer resistant to primary hormone therapy, received high-dose intravenous diethylstilbestrol diphosphate (Stilphostrol [Miles Pharm], DES-P) in a Phase II study using established response criteria. Objective response rate was 17%, while 22% of the patients were subjectively improved. Moderate gastrointestinal toxicity was reported in 10 patients (40%). Thromboembolic complications were seen in 2 (8%). The role of high-dose Stilphostrol in the treatment of hormone-resistant prostate cancer is limited.

Acid Phosphatase↗
PubMed1985

Glutathione peroxidase activity in surgical and autopsied human brains.

Glutathione peroxidase (GSHPx) activity was assayed in normal cerebral gray and white matter samples obtained from frontal, temporal, occipital and parietal lobes during surgical approach to an underlying lesion, and also in normal autopsied human frontal gray and white matter. GSHPx was assayed by a 2 step enzyme reaction which was monitored by following the oxidation of NADPH at 340 nm. It was found that all the brain samples studied contained GSHPx activity. Parietal lobe appeared to have the lowest GSHPx activity compared to temporal, occipital or frontal lobes. Mean enzyme activity in autopsied samples was comparable to that in surgical material. However, considerable loss of activity was observed after 10 years of tissue storage at -80 degrees C.

Adult↗
PubMed1985

The effects of acute hypertriglyceridemia and high levels of free fatty acids on left ventricular function.

The effects of acute hypertriglyceridemia and of high levels of free fatty acids on the left ventricular ejection fraction were studied by radionuclide ventriculography in 20 subjects with and without coronary artery disease. An infusion of approximately 125 ml of a 20% fat emulsion over 25 minutes resulted in an increase of plasma triglycerides to the mean of 820 mg/dl and a fall of the left ventricular ejection fraction from the baseline mean of 62% to 58% (p less than 0.05). Ninety minutes after the intravenous administration of 5000 units of heparin, plasma free fatty acids rose to the mean of 4.6 mmol/L and the mean left ventricular ejection fraction increased to 69% (p less than 0.001). The observed changes in blood lipids were not associated with clinical or ECG evidence of myocardial ischemia. We conclude that acute hypertriglyceridemia causes slight depression of left ventricular performance, while high levels of free fatty acids augment it. However, neither hypertriglyceridemia per se nor its rapid conversion to free fatty acids are likely to cause angina in stable patients with coronary artery disease.

Aged↗
PubMed1985

A clinical trial of aminoglutethimide in advanced postmenopausal breast carcinoma: low response in patients previously treated with medroxyprogesterone.

In an attempt to define the influence of prior hormonal treatments upon aminoglutethimide activity in advanced cancer of the breast, 42 heavily pretreated postmenopausal patients received aminoglutethimide, 4 X 250 mg daily, with hydrocortisone or cortisone. Twenty-six received high doses of medroxyprogesterone before entering this study. There was no significant difference in patients' characteristics with or without medroxyprogesterone pretreatment. A comparison of patients with and without prior medroxyprogesterone shows a significant difference in the response rate to aminoglutethimide-hydrocortisone (4 vs 32%, P = 0.02). In patients pretreated with tamoxifen but not with medroxyprogesterone the response rate to aminoglutethimide was 36%. These results suggest that aminoglutethimide has a low activity in breast cancer patients previously exposed to medroxyprogesterone, an agent with glucocorticoid-like activity inducing adrenal suppression.

Adult↗
PubMed1985

Doughnut sign on bone scintigraphy in angioblastic meningioma.

Bone imaging was performed in a patient with a rapidly expanding parietal bone lesion. The findings on the nuclear medicine study showed a doughnut type lesion. The underlying abnormality was found to be an angioblastic meningioma causing local bone destruction.

Diphosphonates↗
PubMed1985

Hereditary macular dystrophies in relation to radionuclide ocular scintigraphy.

Radionuclide ocular scintigraphy was investigated to determine whether it could detect blood-retinal barrier disruption secondary to retinal disease. Patients were examined who had hereditary macular dystrophies and good correlations were found of the dynamic and equilibrium results obtained on scintigraphy with the clinical disease state. This test may hold promise as another measurement of the disruption of ocular physiology in retinal diseases.

Humans↗
PubMed1984

Parkinson's disease. The possible relationship of laterality to dementia and neurochemical findings.

We examined the relationship of disease laterality to neuropsychological and neurochemical features in patients with idiopathic Parkinson's disease (PD). We tested patients with PD, patients with Alzheimer's type of senile dementia, and a control group neuropsychologically, and we determined their CSF levels of homovanillic acid, 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylglycol, 5-hydroxyindolacetic acid, serotonin, and acetylcholinesterase. The patients with PD were divided into two groups depending on the side of the body with greater disease involvement. Both parkinsonian groups, those more affected on the left (group L) and those more affected on the right (group R), were otherwise similar in all other clinical and historical features. Group L patients showed greater neuropsychological impairments than group R patients. Group L also had significantly higher CSF levels of homovanillic acid and acetylcholinesterase than group R. These findings of neuropsychological and neurochemical differences between groups L and R suggest functional or anatomic asymmetries of dopaminergic systems in the CNS.

Acetylcholinesterase↗
PubMed1984

Response properties of X and Y LGN neurons in Siamese cats.

We investigated quantitatively the receptive-field properties of neurons in the lateral geniculate nucleus of Siamese cats. The experimental animals, "Mid-western" Siamese cats, exhibited varied degrees of ocular misalignment. The percentage of Y-cells, which receive projections from the area centralis, was significantly greater in Siamese cats than in normally pigmented cats. The spatial resolution of many, but not all, X-cells within the central 5 degrees of Siamese cats was reduced. A substantial number of Y-cells had significantly longer latencies to stimulation of the optic chiasm. In addition, some Siamese cat units had abnormal contrast threshold and lineweighting functions along with large receptive field center size and weak inhibitory effects from the RF surround. Finally, large variability was found with respect to the abnormalities among cells within a given cat and more importantly among the individual Siamese cats which we studied.

Animals↗
PubMed1984

The origin of the S (slow) potential in the mammalian lateral geniculate nucleus.

While recording extracellularly from single neurons in the Lateral Geniculate Nucleus (LGN) of cats and monkeys, one often observes, in addition to action potentials, smaller and slower potentials which have been called 'S Potentials' (Bishop et al. 1962). Injection of the sodium channel blocker tetrodotoxin (TTX) into the eye of the cat causes spontaneous and light evoked S potentials to disappear. However, electrical stimulation of ganglion cells axons at the optic chiasm still elicits S potentials. Previous studies have shown that retinal ganglion cell impulses elicit S potentials. Our results prove that ganglion cell impulses are the ONLY source of these potentials; therefore, one can use them as a measure of ganglion cell input to the LGN.

Animals↗
PubMed1984

Reduction of polyunsaturated fatty acid hydroperoxides by human brain glutathione peroxidase.

Glutathione peroxidase (GSHPx) activity in the normal human brain was investigated using lipid hydroperoxides as substrates. Samples were obtained from autopsied frontal gray matter of 5 normal human males with no known central nervous system (CNS) disease. Aliquots were homogenized in 0.9% NaCl-0.5% Triton X-100, and the supernatant solution, obtained after centrifugation at 105,000 X g, was used for GSHPx assay. Glutathione peroxidase was measured by following the oxidation of NADPH at 340 nm. Hydroperoxides of linoleic, linolenic, gamma linolenic, 11,14 eicosodienoic, homo gamma linolenic, arachidonic, docosotetraenoic and docosohexaenoic acids were prepared and used as substrates. All these hydroperoxides were reduced by the brain GSHPx system, but at different rates. Gamma linolenic and docosotetraenoic hydroperoxides were reduced rapidly, whereas the peroxides of docosohexaenoic and 11,14 eicosodienoic were reduced at the lowest rate. Arachidonic hydroperoxide had the highest affinity for the enzyme and linolenic the lowest. Our results suggest that the brain GSHPx system is capable of reducing hydroperoxides of polyunsaturated fatty acids.

Brain↗
PubMed1984

Thallium scintigraphy during dobutamine infusion: nonexercise-dependent screening test for coronary disease.

Exercise thallium scintigraphy has proven to be a sensitive method for detecting coronary artery disease (CAD). However, early redistribution of thallium and inadequate exercise can reduce its sensitivity. In this study, dobutamine was infused in incremental doses (5, 10, 15, and 20 micrograms/kg/min) in 24 patients being evaluated for chest pain. Thallium scintigraphy was completed during the maximum dose of dobutamine tolerated and repeated 4 hours later. Significant CAD was present in 16 patients; the remaining eight had normal coronaries. Exercise ECG was obtained in 23 patients. During dobutamine thallium scintigraphy, reversible perfusion defects occurred in 15 of 16 CAD and in one of eight non-CAD patients, resulting in a sensitivity of 94% and a specificity of 87%. Exercise ECG had a sensitivity of 60% and a specificity of 63%. We conclude that: (1) dobutamine thallium scintigraphy appears to be a sensitive method for detecting significant CAD and provided a more sensitive screening test than exercise ECG; (2) dobutamine thallium scintigraphy is especially useful in patients who cannot exercise; and (3) because imaging occurs during dobutamine infusion, the problem of early redistribution may be mitigated.

Catecholamines↗