Caffeine Pretreatment Enhances Clinical Efficacy and Reduces Cognitive Effects of Electroconvulsive Therapy

In an open clinical trial, depressed patients received age-dosed, brief-pulse electroconvulsive therapy (ECT) either with or without 500 mg i.v. caffeine sodium benzoate before each treatment. Caffeine-pretreated patients required fewer ECT treatments, and after three to four treatments, their Hamilton Depression Scale (HDS) scores were significantly lower. At the end of the ECT course, both groups reached the same reduction in HDS scores. Of five memory tests, one showed better performance at the end of the ECT course for the caffeine-pretreated compared with the non-caffeine-pretreated patients. The results argue that caffeine-modified ECT differs from unmodified ECT in speed of response and the effects on cognitive tests.     

Suramin inhibits DNA damage in human prostate cancer cells treated with topoisomerase inhibitors in vitro

Suramin, a highly sulfonated drug, has been reported to be effective against several human malignancies in vitro and in vivo, and currently is undergoing clinical trials against prostate tumors. The biochemical and molecular mechanisms for suramin's antiproliferative activity are not clear. In order to define the biochemical basis for its antitumor activity and to enhance suramin's chemotherapeutic potential while decreasing its toxicity, we have examined interactions of suramin with topoisomerase I and 11 and several clinically active anticancer drugs against the human prostate (PC3 and LNCaP) cancer cell line. While etoposide, m-AMSA, camptothecin, and SN-38 (the active metabolite of CPT-11) were active in killing prostate cells as single agents, combinations of suramin and these agents were antagonistic against these cells. We found that suramin inhibited activities of purified topoisomerase I and II in vitro as measured by relaxation and cleavage assays. Further studies indicated that suramin also inhibited the drug-induced DNA damage in vitro and in isolated nuclei. These findings indicate that combinations of suramin with topoisomerase inhibitors, for example, VP-16, m-AMSA, or CPT, may not be beneficial to patients receiving suramin-containing chemotherapy. © 1993 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America

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Characterization of a unique cell line (LAZ 221) from human acute lymphocytic ("null" cell) leukemia.

A unique human cell line designated LAZ 221 has been established from the peripheral blood of a patient with acute lymphocytic leukemia of the "null" cell type. The cell line does not possess the Epstein-Barr virus nuclear antigen and has a karyotype of 45,XX,-9,-12,+(9q12q). Both the established cell line and the patient's uncultured blast cells share the same phenotypic markers. They both lack T-cell markers. They fail to form sheep erythrocyte rosettes and do not react with T-cell-specific antisera (TH1-, HTL-), nor do they possess B-cell markers. They do not form rosettes with erythrocytes sensitized with complement, and they are surface immunoglobulin negative. However, they do possess an HLA-D-related glycoprotein complex of 23,000 to 30,000 daltons, an la-like antigen. Thus, LAZ 221 shares the phenotype of the patient's uncultured blasts and is a cell line representative of about 75% of all human acute lymphocytic leukemias. In this respect it differs from previously described human hematopoietic cell lines.     

Summation and discrimination of gratings moving in opposite directions

We have measured the amount of summation occurring at threshold between gratings which move in opposite directions. The small amount of summation observed at low spatial and high temporal frequencies is approximately consistent with the action of direction-selective mechanisms, as proposed by Levinson and Sekuler (1975), provided that probability summation between such mechanisms is taken into account. However, at high spatial and low temporal frequencies much more summation is found, an amount approximately consistent with detection by directionally non-selective mechanisms.We have also measured thresholds for identifying the direction of a moving grating. For those gratings which show little summation, direction of motion is judged correctly at the detection threshold, while for those gratings which show the most summation, the identification threshold is considerably above the detection threshold.     

Pattern discrimination with flickering stimuli

The spatial contrast at which Observers are able to discriminate between horizontal and vertical gratings in a 2AFC task shows the same dependence on spatial and temporal frequency as does 2AFC detection. We conclude that mechanisms carrying information about spatial contrast have their sensitivity to low spatial frequency sinusoidal gratings improved by flicker and that such mechanisms are likely to mediate the detection of low spatial-frequency gratings both at low and at high temporal frequencies.