Glutamate decarboxylase and GABA aminotransferase levels in different regions of rat brain on the onset of Leptazol induced convulsions

The activities of Glutamate decarboxylase (GAD) and Gamma aminobutyric acid (GABA) were studied in three regions of rat brain in heightened neuronal activity resulting in convulsions by Leptazol. These enzymes were studied in preconvulsive, convulsive and post convulsive phases. The activity of GAD decreases significantly in the preconvulsive phase in all the three regions of brain followed by a significant increase during the convulsive and post convulsive phase in cerebral cortex and cerebellum. The activity of GABA-T decreases maximal during the preconvulsive phase followed by convulsive phase. The activity of this enzyme tended to increase to control values when the postconvulsive phase was reached. Therefore, it is suggested that the concomitant decrease of GAD activity and GABA concentration, is probably an important factor in the onset of convulsions.

Prenatal diagnosis of haemophilia-A: a basis for the Pakistani families

OBJECTIVE

To determine the feasibility of a PCR based strategy for prenatal diagnosis of Haemophilia-A in Pakistani Families.

DESIGN

Prospective.

SETTING

Department of Haematology, Armed Forces Institute of Pathology, Rawalpindi.

SUBJECTS

Five families with at least one child affected with Haemophilia-A. Each family comprised of father, mother, affected child and fetus when present.

MAIN OUTCOME MEASURES

Short Tandem Repeat (STR) analysis in the Intron 22 of factor VIII gene.

RESULTS

PCR based analysis of the STR in intron 22 of factor VIII gene showed that the marker was informative in 4/5 study families and could be used in these families for the prenatal diagnosis of Haemophilia-A. In two families prenatal diagnosis was carried out by Chorionic Villus Sampling at 10-13 weeks gestation and the results in both the cases showed a carrier female fetus.

CONCLUSION

Linkage based prenatal diagnosis of Haemophilia-A by an intragenic STR marker is feasible in most of the Pakistani families. The long term response of the Haemophiliac families to the availability of prenatal diagnosis remains to be seen. The STR marker can also be used for carrier detection of female subjects in the affected families.

Down's syndrome: prospects for prevention by antenatal diagnosis

The results of a prospective study on cytogenetic analysis of Chorionic Villus Samples (CVS) taken in early pregnancy (after 10 weeks) from pregnant ladies aged between 22 and 50 years are being presented.

OBJECTIVE

To find out the prevalence of chromosomal defects with advancing age of the mother.

SETTING

Department of Medical Genetics, Armed Forces Institute of Pathology, Rawalpindi.

METHODS

A total of 48 samples have been studied. Ten patients were above the age of 35 years and 38 were below the age of 35 years. Chorionic villus samples were obtained after 10th week of pregnancy through transabdominal approach. Cytogenetic cultures were set up both by the direct and routine methods.

RESULTS

Three out of the seven samples taken from expecting mothers aged above 35 and one culture from a patient aged less than 35, showed trisomy 21.

CONCLUSION

This study highlights the fact that incidence of chromosomal aberrations and the Down's syndrome in particular, increases with the advancing maternal age. Prenatal studies can therefore be utilized to decrease the incidence of various chromosomal abnormalities.

Aplastic anemia or aplastic preleukemic syndrome?

The incidence of aplastic anemia appears to be relatively high in some parts of the world, including Pakistan. Since some of the etiological factors are shared by aplastic anemia and the preleukemic syndrome, there is a strong possibility that a proportion of cases of aplastic anemia may in fact be preleukemia. The study of chromosomes offers a relatively easy method of detecting cases of preleukemia, because some chromosomal abnormalities are frequently observed in this condition. Chromosomal studies were carried out in peripheral blood cell cultures of 31 patients with otherwise typical aplastic anemia. Chromosomal abnormalities were detected in 7 (22.5%) cases. The most common chromosomal abnormality detected was trisomy 8, seen in four cases. Other abnormalities detected were 22q-, t(14;22) and t(15;21), in one case each. These abnormalities have been found to be associated with AML, MDS, ALL, and NHL as well. We hypothesize that a proportion of cases of otherwise typical aplastic anemia may in fact be due to a leukemic process in evolution.