New protein genetic studies in six Amazonian Indian populations

A total of 732 individuals affiliated with six Amazonian Indian populations were variously studied in relation to 26 protein genetic systems. Eleven of them were found to be monomorphic in these groups, in accordance with previous investigations. Similarities and dissimilarities (the latter involving the Rh, Duffy, haptoglobin and transferrin systems) were observed in relation to earlier investigations in four of these populations (Galibi, Palikour, Mundurucu and Tenharim). A dimeric, cathodal variant of albumin was found among two Galibi subjects, and the fairly common occurrence of CP* ACAY among some South American Indian populations was confirmed. The results in the six populations were compared with those from 29 others. When relationships are searched for among tribes of the same linguistic group, the factor that seems to be most influential is geographical localization, an exception being the pattern observed among the Cayapo subgroups. The latter shows genetic differences of the same level of magnitude as those observed among Ge-speaking tribes.     

Genetic variation in some Oxfordshire villages

The patterns of serological polymorphic variety in a group of Oxfordshire populations are related to previously made demographic predictions that the different villages and social classes might be expected to be genetically homogeneous if movement were the main factor determining genetic structure. The predictions are largely fulfilled though there remains a residual pattern of variety which is detectable when all the systems tested are considered together by "genetic distance" examination, and in the case of the geographic variation this pattern reflects the comparative magnitude of the exchanges between the different villages.     

Diosgenin and yamogenin levels in some Indian plant samples

Nephroduodenal fistulas are an uncommon clinical entity characterized by upper abdominal pain and associated with pyelonephritis and renal calculus formation. Most of the recent cases reported are secondary to inflammatory changes in the kidney. Two cases are reported here, one of a nephroduodenal fistula and another of a combined nephroduodenal and nephrocolic fistulae. Carefully monitored X-ray studies determined in both cases the exact site and extent of the fistulae. The optimal treatment is nephrectomy.     

Genetic variation among Trypanosoma cruzi populations

Four experiments examined the effect of naloxone pretreatment on the expression and extinction of ethanol-induced conditioned place preference (experiments 1, 2, 4) or conditioned place aversion (experiments 1, 3). DBA/2 J mice received four pairings of a distinctive tactile (floor) stimulus (CS) with injection of ethanol (2 g/kg) given either immediately before or after 5-min exposure to the CS. A different stimulus was paired with injection of saline. Pre-CS injection of ethanol produced conditioned place preference, whereas post-CS injection of ethanol produced conditioned place aversion. Both behaviors extinguished partially during repeated choice testing after vehicle injection. Naloxone (10 mg/kg) had little effect on the initial expression of conditioned place preference, but facilitated its extinction. Moreover, repeated naloxone testing resulted in the expression of a weak conditioned place aversion to the CS that initially elicited a place preference. In contrast, naloxone (1.5 or 10 mg/kg) enhanced expression of conditioned place aversion, thereby increasing its resistance to extinction. A control experiment (experiment 4) indicated that repeated testing with a different aversive drug, lithium chloride, did not affect rate of extinction or produce an aversion to the CS previously paired with ethanol. These findings do not support the suggestion that naloxone facilitates the general processes that underlie extinction of associative learning. Also, these data are not readily explained by the conditioning of place aversion at the time of testing. Rather, naloxone's effects appear to reflect a selective influence on maintenance of ethanol's conditioned rewarding effect, an effect that may be mediated by release of endogenous opioids. Overall, these findings encourage further consideration of the use of opiate antagonists in the treatment of alcoholism.     

Genetic polymorphism of antithrombin III in five Chinese populations

The genetic polymorphisms of antithrombin III (AT III) in 5 Chinese populations were studied by isoelectric focusing on polyacrylamide gels followed by immunoblotting. The products of two alleles at the antithrombin III locus together with 1 AT III anodic variant and 3 cathode variants were observed. The results revealed that the predominant allele of AT III blood group system in Chinese populations was AT III *1, with frequencies between 0.9773-0.9850. Frequencies of AT III *2 ranged from 0.0091 to 0.0169. These results indicate that the polymorphic information content of AT III blood group system in Chinese populations is limited.     

Genetic diversity in Leavenworthia populations with different inbreeding levels

Levels of neutral genetic diversity within and between populations were compared between outcrossing (self-incompatible) and inbreeding populations in the annual plant genus Leavenworthia. Two taxonomically independent comparisons are possible, since self-incompatibility has been lost twice in the group of species studied. Within inbred populations of L.uniflora and L.crassa, no DNA sequence variants were seen among the alleles sampled, but high diversity was seen in alleles from populations of the outcrosser L. stylosa, and in self-incompatible L. crassa populations. Diversity between populations was seen in all species. Although total diversity values were lower in the sets of inbreeding populations, between-population values were as high or higher, than those in the outcrossing taxa. Possible reasons for these diversity patterns are discussed. As the effect of inbreeding appears to be a greater than twofold reduction in diversity, we argue that some process such as selection for advantageous mutations, or against deleterious mutations, or bottlenecks occurring predominantly in the inbreeders, appears necessary to account for the findings. If selection for advantageous mutations is responsible, it appears that it must be some form of local adaptive selection, rather than substitution of alleles that are advantageous throughout the species. This is consistent with the finding of high between-population diversity in the inbreeding taxa.     

Genetic diversity in natural populations of New World Leishmania

BACKGROUND: Monoclonal precancerous cells undergo successive biochemical and genetic changes during the multistep process of carcinogenesis in the gastrointestinal tract. Despite a high association with intestinal-type stomach cancer (differentiated adenocarcinoma of the stomach), the role of intestinal metaplasia is unclear in stomach carcinogenesis. AIMS: To study the clonality of intestinal metaplasia. METHODS: The clonality of 86 single intestinal metaplastic glands isolated by EDTA treatment from gastrectomy specimens from patients with cancer were investigated. The methylation sensitive restriction enzyme HpaII and polymerase chain reaction (PCR) were used to detect a polymorphic human androgen receptor gene locus linked to an inactive X chromosome. RESULTS: Forty one (48%) intestinal metaplastic glands were heterotypic (mixed cells of different allelic methylation) and 45 (52%) were homotypic (cell population of the same allelic methylation), while almost all the single pyloric glands were homotypic. Eleven of 13 intestinal metaplastic mucosae that were 6 mm in diameter contained glands that had originated from different cells. There were no strong relationships between clonal type and location or histological type of intestinal metaplasia. CONCLUSION: Intestinal metaplasia in general is not a lesion that arises or proceeds monoclonally.     

Genetic aspects of some orofacial anomalies

The increased importance of congenital anomalies in childhood disease is stressed. It is suggested that treatment and research in congential craniofacial anomalies would benefit from centralized registration. Their clinical management should be delegated to centres with a multidisciplinary team. Some problems related to genetic counselling and identification of microforms are illustrated by cleft lip and palate. An account is given of some orofacial anomalies.     

Genetic variability of transferrin subtypes in the populations of India

Five hundred fifteen samples from five populations of India (Brahmins, Marathas, Patels, and Parsees of western India and Hindus of Andhra Pradesh) were analyzed for transferrin subtypes using the isoelectric focusing technique. The allele frequencies of 8444 samples belonging to 93 populations of India have been tabulated, and data were analyzed for genetic diversity among geographic, regional, and socio-cultural groups. Three relatively common alleles, TF*C1, TF*C2, and TF*C3, showed wide variation in various populations of India. Compared with western India, a high frequency of the TF*C2 allele was observed in eastern India. This variation of the TF*C2 allele showed a geographic cline increasing from west to east, giving a significant positive correlation between the TF*C2 allele frequency and longitude. Various genetic processes that possibly maintain TF polymorphism are selection, admixture, genetic drift, and isolation by distance. The possible influence of various genetic processes is discussed.     

Genetic polymorphism of CYP2D6 in North Indian subjects

OBJECTIVES: CYP2D6 polymorphism of clinical relevance occurs with variable frequency in different ethnic groups. Since this polymorphism has not been studied in a North Indian population, the present study was undertaken. METHODS: One hundred healthy unrelated North Indian subjects received 30 mg dextromethorphan (DM) orally at bed-time. The amounts of DM and its metabolite, dextrorphan (DR), excreted in 8 h urine were estimated by high performance liquid chromatography. Metabolic ratio (DM/DR excreted in 8 h) was used as an index of the metabolic status of an individual. RESULTS: The analysis of the data by frequency distribution histogram, probit and NTV plots demonstrated bimodal distribution of the North Indian subjects with respect to hepatic CYP2D6. Out of 100 subjects, 97 were extensive metabolizers (EMs), whereas three were poor metabolizers (PMs). EMs and PMs excreted 29.82 and 2.67 micromol DR (mean value) and 2.59 and 8.82 micromol DM (mean value) in 8 h, respectively. MR and log MR was 197- and 2.2-fold higher in PMs versus EMs. The antimode value of zero was determined by visual observation in frequency distribution histogram and inflection point in probit plot. CONCLUSION: From this study, it can be concluded that the PM phenotype of CYP2D6 occurs with a frequency of 3% (95% confidence interval of 0.33%-6.33%) in North Indians.     

Genetic heterogeneity among the Hindus and their relationships with the other "Caucasoid" populations: new data on Punjab-Haryana and Rajasthan Indian states

The genetic structure of Rajasthan Hindus and Punjab-Haryana Hindus and Sikhs has been studied for ABO, RH, APOC2, C6, C7, F13A, F13B, HP, ORM1, ACP1, ADA, AK1, ESD, GLO1, PGD, PGM1 subtyping, and PGP. This is the first genetic survey on Hindus of Rajasthan. Furthermore, many of these markers have never been studied on Hindus before (APOC2, C6, C7, F13A, F13B, ORM1, PGP). These data, together with those previously available for Hindus, have been utilized to analyze the within-Hindus genetic heterogeneity by RST statistic and correspondence analysis. The genetic relationships of Hindus to other Causcasoid populations were also investigated. In the first analysis, two eastern states (Orissa and Andhra Pradesh) were found to be quite separate from each other and clearly distinct from the northwestern and western states. Out of the markers which could not be utilized in this analysis, PGM1 subtyping turned out to discriminate between the Dravidian-speaking and the Indo-Aryan-speaking Hindus. The second analysis shows a clear-cut separation of Hindus from Europeans, with Near Eastern and Middle Eastern populations genetically in an intermediate position.     

Genetic variants of human T-lymphotrophic virus type II in American Indian groups

The human T-lymphotropic virus type II (HTLV-II) is found in many New World Indian groups in North and South America and may have entered the New World from Asia with the earliest migration of ancestral Amerindians over 15,000 years ago. To characterize the phylogenetic relationships of HTLV-II strains infecting geographically diverse Indian populations, we used polymerase chain reaction to amplify HTLV-II sequences from lymphocytes of seropositive Amerindians from Brazil (Kraho, Kayapo, and Kaxuyana), Panama (Guaymi), and the United States (the Navajo and Pueblo tribes of the southwestern states and the Seminoles of Florida). Sequence analysis of a 780-base pair fragment (located between the env gene and the second exons of tax/rex) revealed that Amerindian viruses clustered in the same two genetic subtypes (IIa and IIb) previously identified for viruses from intravenous drug users. Most infected North and Central American Indians had subtype IIb, while HTLV-II infected members of three remote Amazonian tribes clustered as a distinct group within subtype IIa. These findings suggest that the ancestral Amerindians migrating to the New World brought at least two genetic subtypes, IIa and IIb. Because HTLV-II strains from Amazonian Indians form a distinct group within subtype HTLV-IIa, these Brazilian tribes are unlikely to be the source of IIa viruses in North American drug users. Finally, the near identity of viral sequences from geographically diverse populations indicate that HTLV-II is a very ancient virus of man.     

Genetic variability of apolipoprotein E in a Polish population

Apolipoprotein E (apoE, protein; APOE, gene) is a component of very low density lipoprotein and high-density lipoprotein and plays an important role in lipoprotein metabolism. There are three common alleles of APOE (*2, *3, and *4), which encode the E2, E3, and E4 isoforms of the protein. Distribution of apoE isoforms shows marked variation among various ethnic groups. Direct phenotyping of human APOE in plasma was used to estimate APOE allele frequencies in 137 unrelated blood donors from 3 regions of Poland. The relative frequencies observed for the APOE*2, APOE*3, and APOE*4 alleles were 0.055, 0.839, and 0.106, respectively. The data have been compared with data found in other population groups. The frequency of the APOE*2 allele in Poles was among the lowest in Europe.     

High resolution electron microscopy investigations of interface and other structure defects in some ceramics

To evaluate occurrence of oxidative stress in circulating blood, we developed standard methods to assess (1) granulocytes status as a source of reactive oxygen species (ROS) and (2) lipid peroxidation (LPO). A simplified and highly sensitive assay was developed by utilizing the chemiluminescence (CL) from luminol oxidized by ROS. 1. The CL, from 300 microliters medium containing 1% blood, 10 micrograms/ml luminol and 0.025 microgram/ml phorbol myristate acetate, well reflected the primed granulocyte status induced by in vitro contact with lipopolysaccharide (LPS). This CL was weakened slightly by superoxide dismutase and catalase, but markedly decreased by sodium azide. 2. We determined the optimal conditions for the t-butyl hydroperoxide (t-BuOOH)-stimulated CL method to evaluate plasma LPO in experiments on rat plasma added with phosphatidylethanolamine hydroperoxide (PEOOH). The CL from 300 microliters medium containing 6.67% plasma. 10 micrograms/ml luminol and 5 mumol/ml t-BuOOH was proportional to the added PEOOH amount. The integrated CL of the plasma with 0-60 nmol of PEOOH gave values of 8.280-14.213 x 10(6) counts/60 min/tube. 3. Only 100 microliters of freshly drawn blood was enough for the two CL methods to detect the generation of ROS and the occurrence of LPO. These CL methods enabled the determination of the time course of oxidative stress occurrence in circulating blood of rats treated with 5 mg/kg LPS, i.p.