Polylysine-functionalised thermoresponsive chitosan hydrogel for neural tissue engineering.

Foetal mouse cortical cells were cultured on 2D films and within 3D thermally responsive chitosan/glycerophosphate salt (GP) hydrogels. The biocompatibility of chitosan/GP 2D films was assessed in terms of cell number and neurites per cell. Osmolarity of the hydrogel was a critical factor in promoting cell survival with isotonic GP concentrations providing optimal conditions. To improve cell adhesion and neurite outgrowth, poly-D-lysine (PDL) was immobilised onto chitosan via azidoaniline photocoupling. Increase in PDL concentrations did not alter cell survival in 2D cultures but neurite outgrowth was significantly inhibited. Neurons exhibited a star-like morphology typical of 2D culture systems. The effects of PDL attachment on cell number, cell morphology and neurite outgrowth were more distinct in 3D culture conditions. Neurones exhibited larger cell bodies and sent out single neurites within the macroporous gel. Immobilised PDL improved cell survival up to an optimum concentration of 0.1%, however, further increases resulted in drops in cell number and neurite outgrowth. This was attributed to a higher cell interaction with PDL within a 3D hydrogel compared to the corresponding 2D surface. The results show that thermally responsive chitosan/GP hydrogels provide a suitable 3D scaffolding environment for neural tissue engineering.

Hierarchical gene diversity and genetic structure of tribal populations of Andhra Pradesh, India.

Gene diversity and genetic structure of tribal populations of Andhra Pradesh, India, have been analyzed under a hierarchical model consisting of five regions of the state, tribes within the regions, and local subpopulations within the tribes. Average gene diversity has been estimated from gene frequency data for 15 polymorphic loci by using nested gene diversity analysis of GST. The intralocation coefficient of gene diversity was estimated at 96% of the total, whereas the intertribal, within--and between--regional gene diversities were found to be only 1.90, 0.95, and 1.43%, respectively. The estimate of gene diversity was higher for loci with higher degrees of polymorphism such as ABO, MN, ESD, and PTC and lower for loci with low-level polymorphism and extreme gene frequencies such as Hb, Tf, PHI, 6PGD, and Hp. The nature of selective preference or neutrality at the loci seems to be important in this respect. Tribes of the plains exhibit the least gene diversity, apparently because of higher gene flow among them. The contribution of loci with intermediate gene frequencies in intertribal and regional gene diversity was found to be higher than for loci with extreme allelic frequencies. These results suggest that the most significant component of variation is between individuals within locations and that variation between local subpopulations is negligible in the genetic structure of a population. Forces like selection, gene flow and drift also influence the diversity depending upon the nature of the locus.

Genetic structure of three Naikpod subpopulations of Andhra Pradesh, India.

The genetic structure of three subpopulations of the Naikpod tribe of Andhra Pradesh, India, was examined by studying three blood group, six red cell enzyme, and five protein systems and phenylthiocarbamide taste sensitivity. The gene frequency data of 15 loci are compared among the subpopulations as well as with those reported for other population groups from India. The analysis of gene diversity revealed that the gene differentiation among the subpopulations relative to total population is only 0.02, indicating that the genetic differentiation between subpopulations is very small compared with that within them. This is corroborated by the small genetic distances found among them. The effect of differentiation of microgeographical and breeding isolation on gene diversity and genetic differentiation among the three subpopulations is apparently low.

Serological and biochemical genetic variation among three subpopulations of Naikpod tribe of Andhra Pradesh, India.

A total of 353 blood specimens belonging to three subpopulations of Naikpod tribe of Andhra Pradesh, India, were tested for 12 serological and biochemical marker systems: ABO and Rh blood groups, ESD, SOD1, LDH, MDH1 red cell enzymes, HB and TF, HP, CP, ALB plasma proteins. The results were compared among the three groups by chi-square analysis and they revealed no significant differences among them with the exception of TF system. In addition an attempt was made to compare the observed gene frequencies with those reported for other populations from the Indian subcontinent.

Gc subtyping in south Indian tribal and caste populations.

Seven tribal (Konda Kammara - 2 samples; Koya Dora - 3 samples; Lambadi) and caste (Madiga) populations from Andhra Pradesh (South India) have been analyzed for the distribution of Gc subtypes. The observed heterogeneity in the distribution of Gc1F, Gc1S and Gc2 alleles was found to be statistically significant. Comparisons are made with North Indian populations as well as with those of other racial affiliation. The anthropological impact of the Gc subtype polymorphism is discussed.

Quantitative difference in the new allele transferrin DGond found in the Raj Gond tribal population of Andhra Pradesh (S. India).

Varieties of transferrin alleles have been found in different racial groups of man, and some of them have exhibited polymorphic frequencies, but no record is available to show quantitative differences among the alleles. A quantitative difference has been found in a new allele, Tf DGond, from the Raj Gond tribe whose electrophoretic mobility occupies a position between Tf D1 and Tf DChi. Densitometer scanning of the gels indicating the proportion of Tf DGond to the normal allele Tf C is approximately 2:3. A pedigree study was done to confirm the genetically controlled nature of the allele Tf DGond.

Beta 2-glycoprotein I--a Bi-Allelic polymorphism.

Population samples from Hungary and India have been typed for beta 2-glycoprotein I concentrations. Whereas the Hungarian sample is in fairly good accord with the genetic model set up by Cleve2-beta 2-glycoprotein I concentrations are controlled by two autosomal codominant alleles BgN and BgD-the Indian samples do not fit this model. Thus the Indian data favour the assumption of a more complex genetic mechanism controlling the serum concentration of this protein.

Transferrin, haptoglobin and group-specific component types in tribal populations of Andhra Pradesh.

Five tribal populations, Koya Dora, Raj Gond, Naikpod, Pardhan, and Lambadi from Andhra Pradesh were examined for Tf, Hp, Gc, ceruloplasmin and albumin types. Koya Doras were sampled at five localities to study intra-tribal variation. Tf DChi, a mongoloid genetic marker, was found in high frequencies among Koya Doras (0.029) and Naikpods (0.033) whereas if was absent among Pardhans and showed a very low frequency in Lambadis. A new slow transferrin allele, Tf DGond, is reported from Raj Gonds and is found in polymorphic frequency (0.01). The Hp1 gene frequency ranged from 0.056 to 0.159, and Gc2 ranged from 0.165 to 0.397. No variation was observed with respect to ceruloplasmin. One new albumin variant was found in a single individual of the Koya Dora tribe. The intra-tribal variation in gene frequencies among Koya Doras equalled that found between different tribal populations.

Serum albumin variants from populations of Andhra Pradesh, S. India.

1108 tribal and 1062 non-tribal individuals from three districts of Andhra Pradesh were examined for serum albumin variants. A slow-moving variant, identical to Albumin Kashmir was found in a single Muslim individual. Another new slow-moving variant, faster than Albumin Kashmir found in a single individual of a Koya Dora tribe is designated as Albumin Koya Dora.

Distribution of A1A2BO and Rho (D) blood groups in tribal populations of Andhra Pradesh, South India.

The paper reports the distribution of A1A2BO and Rho (D) blood groups among five tribal populations, Koya Dora, Raj Gond, Naikpod, Pardhan and Lambadi from three districts of Andhra Pradesh, South India. Blood samples from a total of 1090 unrelated individuals were tested. Koya Doras were, however, sampled from five distant localities to find out intratribal variation, if any. In A1A2BO blood group system the combined frequencies of "P1" and "P2" among the five Koya Groups always exceeded the frequency of "q", a characteristic feature of many tribal populations of Andhra Pradesh. However, among Raj Gond, Naikpod, Pardhan and Lambadi tribes the frequency of "q" is higher than "p" with the maximum in Pardhans. The frequency of "r" is always higher than the combined frequencies of "p1" and "p2" except in Raj Gonds. The higher frequency of "q" over "p" among Naikpod, Pardhan and Lambadi tribes is indicative of a tendency towards the distribution pattern found in North India. A few Rh negative persons were detected only in Koya Dora, Raj Gond and Lambadis indicating that the allele r (cde) is present in these populations, although in a low frequency.

The occurrence of DChi and new D and B transferrin variants among caste groups of Andhra Pradesh (S. India).

Serum samples from a total of 862 unrelated individuals belonging to seven Hindu endogamous caste groups residing in Hyderabad and Warangal cities of Andhra Pradesh were examined for electrophoretic variation of transferrin (Tf). In four caste groups, namely, Brahmin, Vysya, Padmashali, and Kapu, the Mongoloid genetic marker DChi was found, with polymorphic frequencies in Brahmin and Vysya groups. The two new D variants found in individuals of Madiga and Mudiraj castes were designated as DMadiga and DMudiraj. Similarly, two new B variants found in individuals of Goldsmith and Madiga castes were designated as BGoldsmith and BMadiga, respectively. These findings suggest a widespread transferrin variation in caste groups of Andhra Pradesh and in the tribal populations of this region.

Genetic distances among the five tribal populations of Andhra, Pradesh, South India.

In this paper, data on genetic distances among five tribal populations ae given. Among the five tribes, Koya Dora, Raj Gond and Naikpod are autochthonous populations of the Deccan plateau whereas the other two groups, Pardhan and Lambadi are migrants. Kova Doras were sampled from five distant localities. Genetic markers typed are: A1A2B0, Rho(D) blood group systems glucose-6-phosphate dehydrogenase deficiency, transferrin, haptoglobin, groupspecific component, haemoglobin, colour-vision deficiency and tastability to P. T. C. Using frequency data for the above nine genetic loci, genetic distances between the five endogamous tribes, and between the five groups of Koya Dora are calculated by adopting the statistical method of Edwards (1971). While genetic distances between Koya Dora, Raj Gond and Lambadi are minimal, the genetic distance between Pardhans and other tribal groups is maximum. Naikpods occupy an intermediate position. The closeness of Lambadi with Koya Dora and RAJ Gond can be regarded as coincidental. Interestingly, the differences in the genetic distance values between five Koya Dora groups are as great as the differences between the five endogamous tribal populations tested for the same loci. Genetic affinities of these tribal populations are discussed in relation to their ethnic origin migration and geographical isolation.