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Biomedical subjects

N Saha

Publications and source records attributed to N Saha.

At least 163 records · Page 9Linked to original sources
PubMed1987

Serum HDL cholesterol and apolipoprotein AI, AII and B levels in Singapore newborns.

The mortality from coronary artery disease (CAD) in Indians is more than three times that in the Chinese and Malays of Singapore. Serum total and HDL cholesterol as well as apolipoprotein (Apo) AI, AII and B levels were determined in a group of 349 newborns (cord blood) from both sexes in these three ethnic groups in order to examine if a trend is reflected at birth. Both serum LDL cholesterol and Apo B levels were low in the newborn, while HDL cholesterol and Apo AII levels were almost the same as in adults. Serum Apo AI levels were also low in newborns. No consistent difference as to ethnic group or sex was observed in any of the parameters investigated, except that the females had significantly higher levels of serum Apo AI in all the ethnic groups. Serum total and HDL cholesterol levels in Singapore newborns were comparable to those reported in Caucasians and Asians. The trends of incidence of CAD were not reflected in the lipid profiles studied at birth.

Apolipoprotein A-I↗
PubMed1987

Haemoglobin, serum iron, transferrin, ferritin concentrations and total iron-binding capacity in erythrocyte glucose-6-phosphate dehydrogenase deficiency.

Erythrocyte deficiency may lead to shortened erythrocyte life-span and also influence iron metabolic processes. Haemoglobin, serum iron, transferrin and ferritin concentrations and total iron-binding capacity (TIBC) were compared in 74 normal and 68 glucose-6-phosphate dehydrogenase (G6PD) deficient subjects to investigate this possibility. All the parameters were measured using standard biochemical and immunoelectrophoretic methods. Haemoglobin and serum iron concentrations were similar in both groups of subjects. It was found that G6PD deficient subjects had significantly greater transferrin (P less than 0.001), ferritin (P less than 0.001) and TIBC (P less than 0.01) values compared to normal subjects. Some possible causes of these observations are discussed.

Adult↗
PubMed1987

Glucose dehydrogenase polymorphism among ethnic groups of Singapore--with report of two additional alleles (GDH4 and GDH5).

Placental glucose dehydrogenase (GDH; E.C.1.1.1.47) polymorphism was studied in 254 Chinese, 104 Malays, and 47 Indians from Singapore using isoelectric focusing. There is suggestive evidence of two additional anodal alleles (GDH4 and GDH5) in addition to the three alleles described in earlier studies. Altogether, 14 phenotypes have been observed in the present investigation, compared with six phenotypes described in earlier studies. It appears that placental GDH is controlled by five codominant autosomal alleles producing 15 possible phenotypes. The gene frequencies of GDH1, GDH2, and GDH3 in these ethnic groups are significantly different from those reported in Caucasians. There were slight differences in the gene frequencies between the three ethnic groups, with those of Indians being nearer to the frequency in Caucasians. In general, the distribution of GDH phenotypes was at Hardy-Weinberg equilibrium in all three ethnic groups studied.

Alleles↗
PubMed1986

Detection and partial characterization of a variant form of cytosolic aldehyde dehydrogenase isozyme.

A rare case of human liver cytosolic aldehyde dehydrogenase (isozyme II) variation discovered in a Chinese autopsy liver specimen is reported. While the major isozyme band was nearly absent, several additional minor bands were observed on isoelectric focusing gel. Rabbit antibodies to purified human liver ALDH II showed immunological cross-reactivity for the variant enzyme bands. The existence of additional minor bands indicates the presence of tetramer hybrid forms made up of normal and variant monomers. The observed abnormality may represent the heterozygous form of ALDH II variation. A similar variant was also detected in erythrocytes of a male Thai student.

Aldehyde Dehydrogenase↗
PubMed1986

Association of red cell glucose-6-phosphate dehydrogenase with haemoglobinopathies.

A total of 1,112 randomly selected Saudi Arabs, of both sexes, living in Jeddah and the surrounding areas were screened for the phenotypic distribution of red cell glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD). They were also investigated for haemoglobin and for thalassaemia. Phenotyping of the haemoglobins and the red cell enzymes was carried out by starch gel electrophoresis and the dye-decolouration screening test, while the investigation for thalassaemia was carried out by globin-chain biosynthesis, followed by column chromatography. The red cell Gd- alleles were significantly associated with the sickle-cell gene in both the males (chi 2(1): AS-28.80; SS-4.89) and females (chi 2(1): AS-10.99; SS-13.16). A similar association was also observed between G6PD deficiency and thalassaemias in males (chi 2(1): alpha-thalassaemia - 3.13; beta-thalassaemia - 11.06) and females (chi 2(1): alpha-thalassaemia - 6.63). However, no such association was detected between red cell 6PGD types and haemoglobin genes. The results suggest that the red cell G6PD deficiency, sickle-cell and thalassaemia genes might have evolved as a result of the same ecological factor, probably malaria.

Adolescent↗
PubMed1986

A study of some blood genetic characteristics of Bedouin and non-Bedouin Arabs of Jordan.

Blood genetic markers were investigated in a sample of 111 Bedouin and 412 non-Bedouin male Arabs of Jordan. The frequencies of the ABO alleles were similar in these two groups, with a relatively high frequency of the O gene (0.63; 0.61). The frequencies of Rh genes were slightly different in these two groups, with a higher Ro and a lower r in the Bedouins. A sub-sample of a smaller size was investigated for the distribution of haptoglobin types, Tf subtypes and red-cell G6PD (glucose 6-phosphate dehydrogenase) phenotypes. There was no significant difference in any of the systems between the two populations. No haemoglobin variant was detected. The study confirms the Arab characteristics of Jordanians with a small degree of African admixture.

Blood Group Antigens↗
PubMed1986

Effects of transferrin genetic phenotypes on total iron-binding capacity.

Serum transferrin level and total iron-binding capacity (TIBC) were studied in a group of 297 healthy adult male subjects having HbAA and G6PDB+ phenotypes by standard chemical and immunoelectrophoretic techniques to examine the influence of different transferrin variants on these parameters. TIBC (67.1 +/- 13.4 mumol/l) and transferrin concentrations (27.0 +/- 3.95 mumol/l) for the whole group were found to be within reported normal values. Serum transferrin concentrations of the subjects having different electrophoretic variants and TfC subtypes of transferrin were not significantly different from each other. There was no significant difference of TIBC in relation to different electrophoretic variants of Tf. However, the TIBC of the subjects of the 1-1 subtype of TfC (70.4 +/- 13.6 mumol/l) was significantly higher than that of the 2-1 subtype (65.0 +/- 12.8 mumol/l; p less than 0.05) as well as that of the 2-2 subtype (60.4 +/- 11.4 mumol/l; p less than 0.01).

Adult↗
PubMed1986

Distribution of red cell G6PD and 6PGD phenotypes in Saudi Arabia.

A total of 1112 randomly selected Saudi Arabs, of both sexes living in Jeddah and the surrounding areas, were studied for the distribution of red cell G6PD and 6PGD phenotypes by the methaemoglobin reduction test and starch-gel electrophoresis. The overall G6PD deficiency was 8.4% in males and 7.0% in females. No deficiency of 6PGD was detected. The gene frequencies at the G6PD locus were as follows: in males [GdB+ - 0.86; GdA+ - 0.05; GdB- - 0.06, GdA- - 0.02] and those in females [GdB+ - 0.85; GdA+ - 0.07; GdB- - 0.06; GdA- - 0.01] respectively. The hyperactive allele, GdBKRT originally detected in the Sudan was also present in a low frequency in Saudi Arabs. The frequency of PGDA and PGDC alleles were found to be 0.94 and 0.06 respectively. There was a significant deviation from the Hardey-Weinberg Equilibrium in the distribution of PGDC alleles with an excess of homozygotes (chi 2(1): 54.0) and lack of heterozygotes (chi 2(1): 7.31) probably due to the practice of inbreeding for many generations.

Alleles↗
PubMed1985

A study of some genetic characteristics of the Fur and Baggara tribes of the Sudan.

The average inbreeding coefficients of the highly consanguineous Fur and Baggara tribes of Western Sudan were 0.04167 and 0.04450, respectively. Two hundred ninety-eight subjects from the two tribes were tested for polymorphism of hemoglobins, seven red cell enzymes, and four serum proteins. The Baggara showed a higher gene frequency of HbS and TfD and lower gene frequency of GdA and PC compared to the Fur. Both tribes showed a low gene frequency of PGM1 and high frequency of G6PD deficiency when compared to other Sudanese tribes. In spite of the high degree of inbreeding, no significant deviation from the Hardy-Weinburg equilibrium was observed in either tribe. The effects of inbreeding seem to be offset by mixing between the two tribes on Gabal Marra Plateau. The flow of the sickle gene from the Baggara into the Fur and other Sudanese tribes is discussed.

Acid Phosphatase↗
PubMed1985

Energy balance study in Singapore medical students.

Energy cost of rest and various common daily activities was measured in 7 male and 16 female medical students by using a Max-Planck respirometer and a Lloyd's gas analysis apparatus. The average weight of male and female subjects during the course of the study was 67.3 +/- 14.2 and 51.2 +/- 5.1 kg, respectively. The average energy expenditure per day was estimated from a diary of activities for a period of 7 days. The average daily intake of energy was computed from food tables and based on weighed amounts of raw materials of food consumed over the same 7-day period when energy expenditure was determined. The average energy expenditure of rest and different activities was found to be significantly lower than the figures published for western subjects. The daily energy intake and expenditure were 2,138 +/- 217 kcal (9.0 +/- 0.9 MJ) and 1,894 +/- 168 kcal (8.0 +/- 0.7 MJ), respectively, in male medical students, giving a positive balance of 244 kcal (1.0 MJ). The values of the same in female medical students were 1,711 +/- 292 kcal (7.2 +/- 1.2 MJ) and 1,474 +/- 211 kcal (6.2 +/- 0.9 MJ) with a balance of 237 kcal (1.0 MJ).

Adolescent↗
PubMed1985

Hepatic storage of iron and ferritin in different ethnic groups in Singapore.

The concentrations of non-haem iron, ferritin and ferritin-iron were measured in the livers of 137 adults and children collected at necropsy. The concentrations of non-haem and ferritin iron were found to be 146.6 +/- 95.2 micrograms/g and 61.6 +/- 32.4 micrograms/g, respectively, in males and 108.0 +/- 61.7 micrograms/g and 60.6 +/- 26.4 micrograms/g, respectively, in females. The values for males in Singapore were lower than those reported in developed Western countries. No correlation was observed between storage iron and age, or ferritin concentration and age. Concentrations of non-haem iron and ferritin were similar for persons dying from accident and coronary heart disease. The non-haem iron concentration in Chinese (187.9 +/- 101.0 micrograms/g) was significantly greater than that in Indians (103.1 +/- 65.8 micrograms/g), while the ferritin concentration in Chinese (6.18 +/- 2.37 mg/g) was significantly greater than either Malays (3.81 +/- 1.8 mg/g) or Indians (3.52 +/- 1.6 mg/g). A significant positive correlation was observed between the non-haem iron and ferritin and also ferritin-iron in Chinese males (r values of 0.678 and 0.598, respectively) and Indian males (r values of 0.576 and 0.612, respectively). However, the correlation between these indices was not significant in the case of Malay males. In premenopausal women the non-haem iron correlated well with ferritin (r = 0.737) and ferritin iron (r = 0.826) while the correlation was lacking in postmenopausal women.

Adolescent↗
PubMed1985

Genetic marker association in schizophrenia: ABO, MN, Rhesus and Lewis blood groups.

One hundred and twelve Chinese male patients suffering from schizophrenia were investigated for the distribution of A1A2BO, MN, Rhesus (genotypes) and Lewis(a) blood groups. The same genetic markers were investigated in 114 Chinese male blood donors. Two more published series--one on the distribution of ABO blood groups and the other on Le(a) blood groups in healthy Chinese males were also used as additional control series. The relative frequencies on these blood groups were examined between the schizophrenics and the control series. There was no significant association of ABO, MN and Rhesus blood groups in schizophrenia. However, a significant association was observed with the Le(a) blood groups with an excess of Le(a) positives in schizophrenia (p less than 0.02).

ABO Blood-Group System↗
PubMed1985

gamma-Aminobutyric acid transaminase (GABAT) polymorphism among ethnic groups in Singapore--with report of a new allele.

gamma-Aminobutyric acid transaminase (GABAT, E.C.2.6.I.19) was phenotyped by starch-gel electrophoresis in post-mortem liver samples from 650 unrelated subjects of either sex, comprising 289 Chinese, 177 Indians, 140 Malays, and 44 from other racial groups from Southeast Asia. The estimated gene frequencies of GABAT1 and GABAT2 were found to be .5779 and .3806 in Chinese, .5678 and .3955 in Indians, and .6214 and .3250 in Malays. The frequency of GABAT1 was .5909 in the mixed group of other races. There was no significant difference in the phenotypic distribution between sexes. A new slow (less anodal) variant (GABAT3) has been observed in low frequency in all the groups (.0415, .0367, 0536, and 0536, and .0568 in Chinese, Indians, Malays, and the mixed-group, respectively). The distribution of GABAT phenotypes was at Hardy-Weinberg equilibrium in all the ethnic groups studied.

4-Aminobutyrate Transaminase↗