Naresh Prasad

Effect of nuclear magnetic resonance on early stages of amphibian development

Frog spermatozoa, fertilized eggs (during second meiotic division), and embryos (during cleavage) were subjected separately to 30 MHz continuous wave NMR exposure in a static magnetic field of 7.05 kG for 20 min and were compared to unexposed groups, at similar stages, with respect to damage in genetic material, interference with meiotic cell division, and impairment in the development of embryos. No significant differences were observed following treatment suggesting that NMR exposure, at the dose used, does not cause detectable adverse effects in this amphibian.

Radiocytogenetic Determination of the Oxygen Enhancement Ratio of Californium 252

Abstract Californium 252 was studied as a possible replacement for radium 226 in radiation therapy. Irradiation of Chinese hamster cells with 252Cf produced an aerobic and anaerobic aberration frequency of 0.0135 and 0.0077 single-hit chromosome aberrations per cell per rad, respectively. The oxygen enhancement ratio was 1.75. This study suggests that 252Cf may be more effective than 226Ra in the treatment of malignant disease.

Esterase, Malate, and Lactate Dehydrogenases Activity in Murine Neuroblastoma

Mouse neuroblastoma tumors have only the fifth isozyme band (A4) of lactate dehydrogenase, whereas this band is missing in the brain which contained four other bands of lactate dehydrogenase. The α-esterase isozyme patterns of tumors, kidney, and brain are similar except that there is an additional slowest-moving form of esterase in all tumor tissues. The malate dehydrogenase pattern is not altered in any of the tissues.

Expression of Lactate and Malate Dehydrogenases in Tumors Induced by SV40 and 7,12-Dimethylbenz(a)anthracene

Isozyme patterns of lactate and malate dehydrogenases were studied in tumors induced by SV40 and 7,12-dimethylbenz(a)anthracene and in established cultures of cells from these tumors. The expression of B polypeptide subunits of lactate dehydrogenase is suppressed similarly by both agents. This may be due to inactivation of the gene at the locus determining the B polypeptide subunit. Malate dehydrogenase isozyme patterns are not changed significantly by the virus or the carcinogen.

The Relative Biological Effectiveness of Californium 252 on Acute Mammalian Lethality

The relative biological effectiveness of 252Cf was compared with radium on the basis of lethality over a 30-day period. Mice were irradiated with 252Cf, radium, and 60Co. Probit analysis of the number of deaths showed an LD50∕30 of 537 rads for 252Cf, 1,286 rads for 240 mg radium, 1,609 rads for 120 mg radium, and 663 rads following high-dose 60Co. The RBE estimate for 252Cf compared to radium over a comparable time interval is 3.01. These findings are consistent with other recently reported RBE values. The 60Co values were not compared due to differences in dose distribution and dose-rate.

Relationship between mitogen response and aryl hydrocarbon hydroxylase in cultured human lymphocytes

Abstract This study was conducted to determine if any relationship existed between Aryl hydrocarbon hydroxylase (AHH) inducibility and mitogen response of cultured lymphocytes from normal healty individuals. The experiments were done repeatedly on the peripheral blood lymphocytes of the same individuals at 4 months intervals during the course of a year. AHH activity was measured by spectrophotofluorometric assay procedures. Mitogen response was measured by counting the incorporation of 3H-Thymidine in cellular DNA using a liquid scintillation counter. Our study indicated large variations in mitogen response of the lymphocytes throughout the study period within the same individuals as well as among the individuals. Variations in AHH inducibility within and among the individuals were also found. The variations were without any pattern. No relationship was found between AHH inducibility and the mitogen response index, suggesting the AHH inducibility test in the mitogen stimulated cultured lymphocytes is not affected by the immune responsiveness of the cells from individual.

Electrophoretic patterns of glucose metabolizing enzymes and acid phosphatase in mouse and human neuroblastoma cells.

Abstract The electrophoretic patterns of glucose metabolizing enzymes and acid phosphatase in mouse and human neuroblastoma cells were investigated. Mouse neuroblastoma cells had one band of lactate dehydrogenase (LDH) and two bands of acid phosphatase, whereas human neuroblastoma cells had five bands of LDH and one band of acid phosphatase. Glucose-6-phosphate dehydrogenase (G-6-PD) and 6-phosphogluconate dehydrogenase (6-PGD) were expressed as a single band in both mouse and human neuroblastoma cells. The electrophoretic pattern of LDH was similar in mouse neuroblastoma cells grown in culture or in vivo. The electrophoretic band of G-6-PD in mouse neuroblastoma cells grown in vivo appeared to be less dense than that observed in cells grown in culture; however, the reverse was true for 6-PGD. Among all enzymes examined, only the electrophoretic pattern of G-6-PD in cAMP-induced “differentiated” mouse neuroblastoma was different in comparison to control cells.

Lymphocyte Replication in Lung Cancer Patients Undergoing Radiotherapy

In vivo and in vitro survival and response of lymphocytes were studied in 12 lung cancer patients before, during and following radiotherapy, and comparisons were made to data from 20 healthy control subjects. Lymphocyte counts of lung cancer patients prior to radiotherapy did not differ significantly from those of control subjects. Following radiotherapy, lymphocyte counts were significantly reduced. The in vitro survival of lymphocytes from lung cancer patients prior to radiotherapy was lower than that of normal controls. Radiation treatment had no effect on lymphocyte survival in vitro. PHA-stimulated lymphoblast formation in lung cancer patients prior to radiotherapy did not differ from that of normal controls, but decreased significantly during radiotherapy.

Effect of radiation in utero on mouse testes lactate dehydrogenase—X

Abstract Lactate dehydrogenase-X(LDH-X), a sperm specific isozyme of mammals, can be used as a marker for active spermatogenesis. LDH-X dectropboretic patterns may also be affected in radiation-induced sterility following in utcro irradiation. To Investigate this relationship pregnant female mice were given 100 red X-radiation on day 19,13 and 17 following gestation. All male offspring were sacrificed 20 days after birth and testes tissues obtained. The testes were homogenized to obtain crude extracts for starch gel electrophoresis and zymogram staining for LDH-X. Results to date show that the LDH-X is not expressed in the testis when fetal irradiation occurred at 10 and 13 days following gestation. Faint bands of LDH-X wcee observed m testes homogenates of mice whose mothers were irradiated 17 days following gestation. Pronounced LDH-X bands were present in all control preparations.

Absence of chromosome damage in the newborn infant following x-ray pelvimetry

Abstract The radiation dose during x-ray pelvimetry to 61 patients was estimated, and the cytogenetic response of peripheral lymphocytes was determined in 25 of their newborn babies. Our calculations resulted in an average midline fetal dose of 1,035 and 1,860 mrads for the patients receiving 2 projections and more than 2 projections, respectively. There was no evidence of radiation induced chromosomal damage in the newborn infants following x-ray exposure in utero.