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Biomedical subjects

N Saha

Publications and source records attributed to N Saha.

At least 181 records · Page 10Linked to original sources
PubMed1984

Mitochondrial malic enzyme polymorphism among different ethnic groups in Singapore.

Mitochondrial malic enzyme (EC 1.1.1.40; MEM) was examined by starch-gel electrophoresis on post-mortem brain samples from 453 unrelated subjects of either sex comprising 161 Chinese, 150 Indians and 113 Malays and 29 from other racial groups. The estimated gene frequencies of MEM1 were found to be 0.7111, 0.6100 and 0.6769 in Chinese, Indians and Malays, respectively. No significant deviation from the Hardy-Weinberg equilibrium was observed in Chinese and Malays. However, there was a significant deviation with a deficiency of heterozygotes among Indians. MES did not show any polymorphism.

Brain↗
PubMed1984

Aldehyde dehydrogenase isozymes in stomach autopsy specimens from Germans and Chinese.

Human stomach aldehyde dehydrogenase (ALDH) isozymes were screened in random autopsy specimens from 66 North German and 33 Chinese individuals. Three ALDH isozymes were identified, which differed in their electrophoretic mobility, affinity to acetaldehyde, propionaldehyde, furfural, and to NAD+ as coenzyme as well as in inhibition by disulfiram, pH optimum and heat stability. While all the German stomach specimens showed ALDH I, ALDH II, and ALDH III isozymes, these isozymes were found in 68, 88, and 99% of the Chinese samples, respectively. The electrophoretic resolution of ALDH III into different activity bands is apparently due to the artefactual formation of secondary isozymes rather than to the existence of genetic variants.

Aldehyde Dehydrogenase↗
PubMed1984

Serum transferrin concentrations and total iron-binding capacities in relation to different haemoglobin phenotypes.

Serum transferrin concentrations and total iron-binding capacities were measured in 184 adult male subjects using standard biochemical methods. The haemoglobin phenotypes of these subjects were also established. Decreases in both of these parameters were observed when HbAE, beta-thalassaemia trait (raised level of HbA2), and HbEE subjects were compared to HbA subjects. Though the decrease was slight in the cases of HbAE and beta-thalassaemia trait, HbEE subjects had significantly reduced values. Both the parameters were also significantly reduced when values from HbEE subjects were compared to those from HbAE and beta-thalassaemia trait. It is suggested that marginal liver damage is present in subjects with homozygous HbE, leading to a reduction in transferrin production.

Hemoglobin A↗
PubMed1984

Distribution of glucose-6-phosphate dehydrogenase phenotypes in five East Asian population groups.

1205 adult males comprising 287 Chinese from Singapore, 448 Thais, 123 Filipinos, 140 Koreans and 207 Taiwanese were investigated for the phenotypic distribution of red cell G6PD by starch-gel electrophoresis. The incidence of the deficient alleles (GdB- and Gd-) was found to be as follows: Chinese - 8%, Thais - 6.7%, Filipinos - 13%, Koreans - 3.5%, and Taiwanese - 11.6%. Low frequency of fast variant of Gd with normal activity was observed in Filipinos (0.8%), Koreans (2.1%) and Taiwanese (0.5%). Two slow variants of Gd alleles with normal activity were detected. The one with 95% mobility was present in Chinese (2.1%), Thais (1.6%), Filipinos (0.8%), Koreans (1.4%) and Taiwanese (1.0%), while the other slower variant was encountered only in Chinese (1.0%) and Thais (0.2%). One instance of Gd B with about 150% enzyme activity was detected in a Thai. Partially deficient fast variant of G6PD was observed in one Thai and one Filipino.

Alleles↗
PubMed1984

Distribution of haptoglobins in different dialect groups of Chinese, Malays and Indians in Singapore.

A total of 870 subjects comprising 524 Chinese (from different dialect groups), 231 Malays and 115 Tamil Indians were investigated for the distribution of haptoglobin types and ABO blood groups. Haptoglobins were typed by PAG electrophoresis using discontinuous buffer system. The frequencies of Hp,1 Hp2 and Hp0 were found to be 0.330, 0.670 and 0.029 in Chinese; 0.298, 0.702 and 0.004 in Malays; and 0.167, 0.833 and 0.009 in Indians. The Hainanese had the highest frequency of Hp1 (0.375) followed by Cantonese (0.348), Teochew (0.333) and Hakkas (0.288). The distribution of all the phenotypes of haptoglobin was at equilibrium in all the population groups studied. No association of ABO blood groups was detected with the haptoglobin types. However, there was an excess of AB blood group in persons carrying Hp2 compared with those with Hp1.

ABO Blood-Group System↗
PubMed1983

The inter- and intra-tribal distribution of red cell G6PD phenotypes in Sudan.

1,416 males and 564 female subjects from four Negroid and five Arab tribes and a group of mixed tribes of the Sudan were investigated for the phenotypic distribution of red cell glucose-6-phosphate dehydrogenase by starch gel electrophoresis. In general, the tribes of Negroid origin had higher frequency of GdA compared to the tribes of Arab ancestry. However, the Nilotes showed a lower frequency of GdA allele and the Mahass tribe claiming an Arab origin had a higher frequency of GdA. The immigrant groups from the neighbouring African countries also had a higher frequency of GdA. GdB (Khartoum) was present in low frequencies in both the Arab and Negroid tribes. A great deal of intratribal variation in the phenotypic distribution of G6PD was observed in the Nuba and Gáali tribes from different localities.

Alleles↗
PubMed1982

Distribution of serum proteins, red cell enzymes and haemoglobins in vitiligo.

125 Sudanese patients suffering from vitiligo were investigated for the distribution of serum proteins (haptoglobins and transferrins), red cell enzymes (acid phosphatase, 6-phosphogluconate dehydrogenase, phosphoglucomutase and glucose-6-phosphate dehydrogenase) and hemoglobins. The results were compared with the published healthy population series investigated for the same genetic markers. There was no significant association with any of the marker systems in vitiligo except glucose-6-phosphate dehydrogenase. An excess deficiency of this enzyme was observed in vitiligo patients compared to the control series.

Blood Proteins↗
PubMed1982

Energy cost of some common physical activities of Chinese schoolboys.

14 Chinese schoolboys aged 12-14 years, resident in Singapore coming from affluent homes, were tested for the determination of energy cost, pulmonary ventilation (PV) and oxygen (O2) consumption at rest and during some common physical activities by using a Max-Planck respirometer and Lloyds gas analysis apparatus. The study was undertaken for comparison with the results of a similar investigation of Indian schoolchildren of the same age-group living in a hostel under hostel discipline and diet in Singapore reported earlier. The energy cost (kcal/min, kJ/min) in these Chinese children was found to be significantly higher, but the energy cost per kilogram body weight per hour was found to be significantly lower than in the Indian children. PV in liters per minute was significantly higher in Chinese schoolboys during all physical activities except lying at rest, sitting and running. O2 consumption in liters per minute was also significantly higher during all activities except lying at rest and sitting.

Adolescent↗
PubMed1982

Sickle cell gene and liver functions in a Sudanese population.

401 subjects of both sexes and with ages ranging from 5 to 50 years were investigated for haemoglobin phenotypes by starch-gel electrophoresis. Concentrations of blood haemoglobin, serum total protein, albumin, globulin, total cholesterol and serum transaminases (SGOT and SGPT) were determined to examine the influence of the sickle cell gene on these biochemical parameters. The carriers of sickle cell trait had higher levels of SGOT and SGPT compared to those with haemoglobin A and homozygous sickle cell haemoglobin. The carriers of homozygous sickle cell had lower levels of haemoglobin, total cholesterol and transaminases. No significant difference was observed in serum protein concentration in relation to the presence of sickle cell gene.

Adolescent↗
PubMed1981

Distribution of the lactase phenotypes in the population of the Democratic Republic of the Sudan.

The distribution of the adult lactase phenotypes, lactose absorption, and lactose malabsorption, was determined by a field version of the hydrogen breath test for disaccharide absorption in a sample of 563 subjects residing in the Democratic Republic of the Sudan. Relatively high proportions of lactose absorption were found in the northern nomadic groups who rely heavily on dairying for their livelihood. Residential Nile valley populations revealed intermediate frequencies of the two phenotypes whereas the negroid populations of the south exhibited a high prevalence of lactose malabsorption irrespective of their economic status with respect to agriculture and dairying. The frequency of the "hypolactasia allele" ranged between 0.6 and 0.87 in the major regional groups.

Adult↗
PubMed1981

Phenotypic and quantitative relationship of red cell acid phosphatase with haemoglobin, haptoglobin, and G6PD phenotypes.

The phenotypic and quantitative relationship of red cell acid phosphatase with haemoglobin, haptoglobin, and G6PD phenotypes was investigated in three populations in the Sudan and one population in Nilgiris, India. No significant consistent association of red cell acid phosphatase phenotypes was observed with these polymorphisms. However, there was a lack of acid phosphatase AB in G6PD deficient subjects from Nilgiris. The relative quantitative expression of red cell acid phosphatase genes PA, PB, and PC was 1.0, 1.2, and 1.3, respectively. The red cell acid phosphatase activity was higher (15%) in the presence of raised haemoglobin A2 and in sickle cell anaemia (21%). Those with Hp2 had 18% higher level of acid phosphatase than those with Hp1. G6PD deficient subjects had a lower level of acid phosphatase activity (20%) than those with normal G6PD activity.

Acid Phosphatase↗
PubMed1981

Erythrocyte glutathione reductase polymorphism in a Sudanese population.

414 random samples of blood collected from unrelated male blood donors in Khartoum were analysed for erythrocytic glutathione reductase (GSR) phenotypes in relation to glucose-6-phosphate dehydrogenase (G6PD) and haemoglobin types by starch gel electrophoresis. The overall frequencies of GSR1 and GSR2 were found to be 0.9493 and 0.507, respectively. The frequency of GSR0 was very low (0.0241). The frequency of GSR2 was higher in G6PD-deficient subjects compared to normal subjects. GSR phenotypes were not related to the haemoglobin types. However, there was an excess of GSR0 in subjects with haemoglobin AS.

Erythrocytes↗
PubMed1981

A genetic study of the Jordanians.

A total of 543 random samples of blood collected from unrelated male blood donors of Amman, Jordan, were analysed for ABO and Rh(D) blood groups, serum haptoglobin, transferrin and albumin; glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, lactate dehydrogenase; and haemoglobin phenotypes. The results of the study establish the Arab characteristics of the population with no or minimal presence of African genes.

Blood Group Antigens↗
PubMed1981

Quantitative expression of G6PD activity of different phenotypes of G6PD and haemoglobin in a Sudanese population.

597 unrelated persons, comprising of 401 males and 196 females, were investigated for glucose-6-phosphate dehydrogenase (G6PD) and haemoglobin phenotypes by starch gel electrophoresis. The levels of G6PD activity were assayed in order to study the quantitative expression of G6PD phenotypes and the influence of haemoglobin phenotypes on such expression. There was no significant different in the levels of G6PD activity in subjects with GdA or GdB. The mean levels of the enzyme activity were 165.5 +/- 33.7 and 164.8 +/- 33.8 IU/10(12) red cells in males and 159.3 +/- 27.8 and 163.4 +/- 33.5 IU/10(12) red cells in females, respectively. 14 subjects with Gd(+) "Khartoum" had significantly (p less than 0.001) higher level of enzyme activity with a mean above 200 IU/10(12) red cells. On the other hand, 20 subjects with GdB(int) (demonstrated by visual comparison of starch gel) showed significantly (p less than 0.001) lower levels of enzyme activity (107.6 +/- 23.5 IU/10(12) red cells). The heterozygotes GdAB also had slightly, but not significantly lower levels of enzyme activity than either GdA or GdB. The mean level of activity for GdAB was 140.1 +/- 29.4 IU/10(12) red cells.

Adolescent↗