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Biomedical subjects

M A Ramadan

Publications and source records attributed to M A Ramadan.

8 recordsLinked to original sources
PubMed1991

Cytotoxic activity of Amaryllidaceae alkaloids from Crinum augustum and Crinum bulbispermum.

The cytotoxic activity of five minor Amaryllidaceae alkaloids and one flavan isolated from Crinum augustum Rox and Crinum bulbispermum Milne were tested on human leukemic Molt 4 cells. Whereas the crinine-type alkaloids (6 alpha-hydroxycrinine, powelline) and the new type augustamine did not even inhibit the growth of Molt 4 cells, the lycorine-type alkaloid (pratorinine) and the crinine-type alkaloid (6 alpha-hydroxybuphanisine) showed a moderate cytotoxic activity and the flavan (4'-hydroxy-7-methoxyflavan) showed an important cytotoxic effect.

Alkaloids↗
PubMed1979

Nucleic acids and protein changes in normal and pre-eclamptic placentae.

DNA and RNA assayed in the placentae of three groups of pregnant women: normal second trimester (16-28), normal third trimester (28 weeks up to term) and in preeclampsia. The protein level in the placentae of the three groups was also assayed. The proteins, DNA and RNA all decreased after 28 weeks and up to term in normal pregnancy. In pre-eclampsia DNA and RNA showed a significant increase compared with cases of normal third trimester pregnancy. Whereas the proteins also showed an increased level, this was still less than its concentration during the second trimester of pregnancy. Protein/DNA and RNA/DNA ratios were calculated for the three groups. These ratios showed a gradual decrease during normal pregnancy from 16 weeks up to term, but with a sharper decrease in pre-eclampsia.

Adult↗
PubMed1979

Morphologic and biochemical characteristics of transplantable neurogenic tumors induced by N-ethyl-N-nitrosourea in inbred BD IX rats.

Brain and nerve tumors were induced transplacentally in inbred BD IX rats by systemic application of N-ethyl-N-nitrosourea. Because primary gliomas and neurinomas produced in this way are composed of heterogeneous cell populations, changes in tumor morphology were expected to occur during serial transplantation in syngeneic hosts. In this study such changes in morphology were correlated with the expression of two biochemical nervous system markers, S-100 protein and 2',3'-cyclic nucleotide 3'-phosphohydrolase. Several changes were observed during serial transplantation, including increased growth rate (even after one passage), preferential growth of anaplastic versus differentiated glial and Schwann's cells, varying degrees of fibrosarcomatous changes after prolonged serial transplantation, and reduced levels of S-100 protein. In contrast, tumors derived from biochemically differentiated clonal cell lines retained their morphologic and biochemical characteristics to a much greater extent, even after prolonged periods of sc transplantation.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1976

Leucine aminopeptidase activity in maternal, cord blood and placenta of normal pregnancy and in pre-eclampsia.

1) Leucine aminopeptidase (LAP) was determined in maternal and fetal blood and in the placenta of mild and severe pre-eclamptic patients, then compared to the levels of normal pregnancy. 2) The enzyme activity increased significantly in severe pre-eclampsia as compared with the mild type and with normal pregnancy. 3) In mild pre-eclamptic patients LAP activity of maternal and cord blood did not increase significantly as compared with the normal cases but the placenta showed a slight decrease. 4) The enzyme level in cord blood did not increase markedly in pre-eclampsia.

Adult↗
PubMed1976

Ceruloplasmin and copper level in maternal and cord blood and in the placenta in normal pregnancy and in pre-eclampsia.

Copper and ceruloplasmin were assayed in maternal and cord blood sera and in the placenta of 10 women with normal pregnancies, in 10 patients mild and 10 with severe pre-eclampsia. Copper and ceruloplasmin levels were significantly elevated in the maternal blood of pre-eclamptic patients as compared with normal pregnant women. The placental and cord blood concentrations of copper and ceruloplasmin showed non-significant changes, which indicates that their increase in the maternal blood is not of placental origin.

Ceruloplasmin↗
PubMed1975

Transplacental induction of neurogenic tumors in BD IX rats by intragastric administration of ethylnitrosourea precursors.

The concurrent daily intragastric administration of ethylurea at two dose levels (50 mg/kg and 100 mg/kg bodyweight) together with one dose level of sodium nitrite (50 mg/kg bodyweight) by a stomach tube to pregnant BD IX rats from day 15 to day 22 of gestation resulted in the induction of neurogenic tumors in all offspring. Since both ENU-precursors alone do not produce neurogenic tumors, these results are evidence of ENU formation from its precursors under the influence of gastric juice. Differences in the survival time and the incidence of tumors at both dose levels were not significant. The amount of ethylnitrosourea synthesized in the animals was very close at both dose levels, and was dependent on the amount of sodium nitrite applied. The experimental results are consistent with the conclusion, that the rat fetuses had been exposed to a total amount of about 60 mg/kg ethylnitrosourea. Neurogenic tumors dominated with 98% incidence over the non-neurogenic. The incidence of neurogenic tumors per rat was high (6.0 for Group I and 6.7 for Group II). Neurogenic tumors were equally distributed among the central and peripheral nervous systems. The neurogenic tumors induced with the precursors of ethylnitrosourea were morphologically similar in all aspects to those induced with the carcinogen itself and could be classified as oligodendroglioma, astrocytoma, mixed glioma, anaplastic glioma, glioependymoma, ependymoma, and neurinoma. Three unusual tumors were found: one early anaplastic "septum ependymoma" in the dorsal column of the spinal cord, and two special mixed tumors of the cranial nerves, i.e. a neurinoma with portions of an oligodendroglioma and a neurinoma with parts of an invasive ependymoma.

Animals↗
PubMed1975

Serum and Placental lactic dehydrogenase and alkaline phosphatase isoenzymes in normal pregnancy and in pre-eclampsia.

LDH isoenzymes and heat-stable alkaline phosphatase were studied in the serum and placental extract of 20 cases of pre-eclampsia and 10 normal pregnancies as a control. The starch-gel electrophoretic serum and placental isoenzymogram showed that LDH4 and LDH5 were the main isoenzymes in the placenta while LDH1 and LDH2 were the main isoenzymes in the serum in pre-eclampsia. The electrophoretic serum protein pattern in pre-eclamlobulins with decreased albumin fraction, while in the placenta, the albumin fraction was increased together with a decrease in the alpha-globulins. The electrophoretic pattern of serum alkaline phosphatase showed a main band of activity at the B-globulin zone in all cases of normal pregnancy and pre-eclampsia. In the placenta, two additional bands were detected.

Alkaline Phosphatase↗