Genetic affinities among Mongol ethnic groups and their relationship to Turks

The central Asian country Mongolia is home to more than 20 tribes and ethnic groups, some of which are related to neighboring Turkic populations. The main Mongolian people, Khalkha, live in central and eastern Mongolia while the Tsaatan minority lives in the north of the country. The Oold minority is from the western Altai mountain region and live in close proximity with Turkic people. We have typed the HLA-A, -B, -Cw, -DRB1 and -DQB1 loci by PCR-SSP in these three Mongolian populations as well as a sample of the German population. To examine their genetic relationships, a sample of the Turkish population already typed at the HLA-A, -B and -DRB1 loci were used. Altogether five populations were analyzed: Khalkha (n = 100), Tsaatan (n = 72), Oold (n = 52), German (n = 260) and (Anatolian) Turkish (n = 498). Nei's unbiased genetic identity (GI) and genetic distance (GD) were estimated from genotypes using PopGene v1.31, and dendrograms were constructed using phylip. The results suggested a close relationship of the Khalkha to the Tsaatan. The Turks and Germans were equally distant to all three Mongolian populations. These results confirmed the lack of strong genetic relationship between the Mongols and the Turks despite the close relationship of their languages (Altaic group) and shared historical neighborhood. This study has provided useful population data for genetic and anthropologic studies bridging eastern and western populations.

Brain glioma and human leukocyte antigens (HLA)--is there an association

Expression of human leukocyte antigens (HLA) is important for the immune response against infectious agents and malignant cells. Association of single HLA antigens or HLA haplotypes with disease has been investigated previously, and positive correlations between HLA and some cancers, such as cervical or nasopharyngeal carcinomas have been reported. In the present study, HLA antigen frequencies of 65 adult Caucasian patients with low-grade, anaplastic, or malignant astrocytic glioma (WHO grades II-IV) were compared with 157 racially similar, asymptomatic control individuals. Both standard serologic and PCR techniques for HLA typing were employed for all patients and controls. Our results suggest a positive association between single HLA antigens and presence of symptomatic cerebral glioma. Compared with the control population, patients positive for HLA-A*25 had a 3.0-fold increased risk of glioma (p = 0.04), patients positive for HLA-B*27, a 2.7-fold risk (p = 0.03), and patients positive for HLA-DRB1*15, a 2.2-fold risk (p = 0.03), whereas HLA-DRB1*07 was associated with a 0.4-fold decreased risk of glioma (p = 0.02). Occurrence rate of some HLA antigen combinations and estimated haplotypes was also different in glioma patients. Thus, HLA-DRB1*15:DRB5*(51) occurrence in combination with HLA-DRB1*11 was associated with a 13.4-fold increased risk of glioma (p = 0.001), and the incidence of HLA-Cw*6:DRB1*07 with a 0.2-fold decreased risk of glioma (p = 0.03). In conclusion, single HLA antigens and their combinations and estimated haplotypes are possibly significantly more or less frequent in persons developing symptomatic cerebral glioma during their adult life, compared with asymptomatic individuals.

[Nocturnal continuous subcutaneous insulin infusion--a therapeutic possibility in labile type I diabetes under exceptional conditions]

The whole-day continuous subcutaneous insulin infusion (CSII) with portable pumps in daily blood glucose autocontrol guarantees a more stabile and favourable glycaemia than multiple injections in labile type I diabetics. The success is mainly to be traced back to the continuous replacement of the basal secretion, particularly to the nocturnal fasting phase. In this study the effect on the glycaemia is investigated with exclusively nocturnal administration of the CSII under maintenance of multiple insulin injections during this day. In a group of 18 type I diabetics the nocturnal CSII in comparison to intermediate insulin administrations in the evening led to a significant improvement of glycaemia (p less than 0.01), in particular to the decrease of the fasting blood sugars (p less than 0.05). In two casuistic observations in comparison to all the other conventional methods for the compensation of the nocturnal glycaemia (depot insulin, nocturnal injection of normal insulin) the nocturnal CSII proved to be superior. Therefore, the nocturnal CSII is an--though more rarely to be used--alternative, which may be taken into consideration, of a whole-day CSII is temporarily unwished for.