The Tyrolean Iceman is an extraordinarily well-preserved natural mummy that lived south of the Alpine ridge ~5,200 years before present (ybp), during the Copper Age. Despite studies that have investigated his genetic profile, the relation of the Iceman´s maternal lineage with present-day mitochondrial variation remains elusive. Studies of the Iceman have shown that his mitochondrial DNA (mtDNA) belongs to a novel lineage of haplogroup K1 (K1f) not found in extant populations. We analyzed the complete mtDNA sequences of 42 haplogroup K bearing individuals from populations of the Eastern Italian Alps – putatively in genetic continuity with the Tyrolean Iceman—and compared his mitogenome with a large dataset of worldwide K1 sequences. Our results allow a re-definition of the K1 phylogeny and indicate that the K1f haplogroup is absent or rare in present-day populations. We suggest that mtDNA Iceman´s lineage could have disappeared during demographic events starting in Europe from ~5,000 ybp. Based on the comparison of our results with published data, we propose a scenario that could explain the apparent contrast between the phylogeographic features of maternal and paternal lineages of the Tyrolean Iceman within the context of the demographic dynamics happening in Europe from 8,000 ybp.

This study reports on variations at the mitochondrial DNA (mtDNA) hypervariable region 1 (HVR-1) and at seven Y-chromosome microsatellites in an African-American population sample from Chicago, IL, USA. Our results support the hypothesis that the population studied had undergone a European male-biased gene flow. We show that comparisons of intra-and inter-population diversity parameters between African-Americans, Europeans and Africans may help detect sex-biased gene flow, providing a complement to quantitative methods to estimate genetic admixture.

In this study, we report the genetic variation of autosomal and Y-chromosomal microsatellites in a large Cameroon population dataset (a total of 11 populations) and jointly analyze novel and previous genetic data (mitochondrial DNA and protein coding loci) taking geographic and cultural factors into consideration. The complex pattern of genetic variation of Cameroon can in part be described by contrasting two geographic areas (corresponding to the northern and southern part of the country), which differ substantially in environmental, biological, and cultural aspects. Northern Cameroon populations show a greater within- and among-group diversity, a finding that reflects the complex migratory patterns and the linguistic heterogeneity of this area. A striking reduction of Y-chromosomal genetic diversity was observed in some populations of the northern part of the country (Podokwo and Uldeme), a result that seems to be related to their demographic history rather than to sampling issues. By exploring patterns of genetic, geographic, and linguistic variation, we detect a preferential correlation between genetics and geography for mtDNA. This finding could reflect a female matrimonial mobility that is less constrained by linguistic factors than in males. Finally, we apply the island model to mitochondrial and Y-chromosomal data and obtain a female-to-male migration Nnu ratio that was more than double in the northern part of the country. The combined effect of the propensity to inter-populational admixture of females, favored by cultural contacts, and of genetic drift acting on Y-chromosomal diversity could account for the peculiar genetic pattern observed in northern Cameroon.

The hypervariable region-1 and four nucleotide positions (10400, 10873, 12308, and 12705) of the coding region of mitochondrial DNA (mtDNA) were analyzed in 441 individuals belonging to eight populations (Daba, Fali, Fulbe, Mandara, Uldeme, Podokwo, Tali, and Tupuri) from North Cameroon and four populations (Bakaka, Bassa, Bamileke, and Ewondo) from South Cameroon. All mtDNAs were assigned to five haplogroups: three sub-Saharan (L1, L2, and L3), one northern African (U6), and one European (U5). Our results contrast with the observed high frequencies of a Y-chromosome haplogroup of probable Asian origin (R1*-M173) in North Cameroon. As a first step toward a better understanding of the evident discrepancy between mtDNA and Y-chromosome data, we propose two contrasting scenarios. The first one, here termed "migration and asymmetric admixture," implies a back migration from Asia to North Cameroon of a population group carrying the haplotype R1*-M173 at high frequency, and an admixture process restricted to migrant males. The second scenario, on the other hand, temed "divergent drift," implies that modern populations of North Cameroon originated from a small population group which migrated from Asia to Africa and in which, through genetic drift, Y-chromosome haplotype R1*-M173 became predominant, whereas the Asian mtDNA haplogroups were lost.

African Americans show a prevalence of obesity, non-insulin-dependent diabetes mellitus (NIDDM) and glucose-impaired tolerance substantially higher than both African native populations and sympatric populations of European origin [ 1 Harris M.I. Flegal K.M. Cowie C.C. et al. Prevalence of diabetes, impaired fasting glucose, and impaired glucose tolerance in U.S. adults. The Third National Health and Nutrition Examination Survey, 1988–1994. Diab. Care. 1998; 21: 518-524 Crossref PubMed Scopus (2459) Google Scholar , 2 Cossrow N. Falkner B. Race/ethnic issues in obesity and obesity-related comorbidities. J. Clin. Endocrinol. Metab. 2004; 89: 2590-2594 Crossref PubMed Scopus (355) Google Scholar ]. This raises the possibility that populations of African origin possess thrifty genetic variants, selected because of their increased metabolic efficiency in conditions of limited food supply, which would instead predispose their carriers to an increased risk of obesity and NIDDM when food access becomes no longer limited [ 3 Neel J.V. Diabetes mellitus: a thrifty genotype rendered detrimental by “progress”?. Am. J. Hum. Genet. 1962; 14: 353-362 PubMed Google Scholar , 4 Cooper R. Diabetes and the thrifty gene. Lancet. 1994; 334: 1648 Abstract Scopus (5) Google Scholar ].

The effect of trigeminal electrical stimulation on cerebral blood flow has been studied in conditions of normal or reduced cerebral blood flow (CBF).

POPULATION: We have analyzed the distribution of allele frequencies at three microsatellite loci (CD4, FES, and F13A1) among individuals living and born in central-southern Sardinia (Italy), in a zone called “Trexenta” within the province of Cagliari ( n (cid:1) 50). This area has been already studied from the linguistic and genetic point of view (1) using classical polymorphism at protein level. Informed consent was obtained from all donors.

We have studied the polymorphism of HLA class I in two West African Pygmy populations, namely, the Bakola from Cameroon and the Mbenzele from the Central African Republic. A unique number of HLA alleles and haplotypes showed specific patterns of these populations. In this study, we identify two alleles (B*37, B*41) and three haplotypes (A*30-B*37, A*66-B*41 and A*68-B*58) that appear to be 'private' or typical of Western Pygmies. These data reflect similarities with the AKA Pygmies from the Central African Republic. On the other hand, we failed to identify alleles that are found at high frequencies among other sub-Saharan populations (B*42, B*51). Allelic and haplotypic frequency distributions show differences between the two Pygmy groups, e.g. B*35 was very common in the Mbenzele but has been found to be absent in the Bakola. In contrast, B*53, which is found in the Bakola, has been found to be rare in the Mbenzele Pygmies. In order to analyse the genetic relationships of the Bakola and Mbenzele Pygmies with other sub-Saharan populations, HLA gene frequencies were subjected to the Neighbour-Joining tree analysis. The Mbenzele, Bakola and AKA were found to be relatively close to each other and isolated from other sub-African populations. However, both the genetic distances and the within-group variation suggests that the Bakola are more admixed with Bantu farmers than Mbenzele.

We review a series of 1,280 operated cases of carpal tunnel syndrome (CTS), with an unexpected high frequency of transverse muscular fibers within the carpal canal (11%), particularly in a group of young male patients under 30 years of age. This abnormal presence of muscle fibers could explain the early development of CTS in young male workers.

We recently proposed a biochemical model of genetic resistance to falciparum malaria based on the role of oxidant stress (of parasitic origin) in inducing the irreversible oxidation of hemoglobin and its binding to the erythrocyte membrane (Destro-Bisol et al. 1996). To test the model, we analyzed the relationships between the polymorphisms at the hemoglobin beta chain (HBB) and red cell glutathione peroxidase (GPX1) loci in 18 populations that had been subjected to endemic malaria (Cameroon and Central African Republic). The erythrocytes of GPX1*2 heterozygotes should be more efficient in sheltering the cell membrane from irreversible oxidation and binding of hemoglobin caused by the oxidant stress exerted by Plasmodium falciparum. According to our model, the GPX1*2 allele has an epistatic effect on the HBB*A/*S genotype by lowering its protection against falciparum malaria, In turn, this should decrease the fitness of the HBB*A/*S-GPX1*2/*1 genotype. Our predictions were confirmed, in fact, we observed a clear trend toward a dissociation between the HBB*A/*S and GPX1*2/*1 genotypes in the overall data. To test alternative hypotheses, we also analyzed the genetic variation at 9 protein and 10 autosomal microsatellite loci at both the single- and the 2-locus level, We also discuss the possible relevance of an alternative biochemical pathway, The results further support the conclusions of our study because the dissociation between the GPX1*2/*1 and HBB*A/*S genotypes does not appear to be related either to a general decrease in heterozygosity or to an increased risk of sudden death in HBB*A/*S individuals.

BACKGROUND: In order to investigate the aetiology of uraemic neuropathy, we evaluated the neurotoxic activity of plasma from uraemic patients. To this end we prepared a concentrate (1:1000) of 2-60 kDa MW compounds from paired filtration dialysis ultrafiltrate and evaluated its activity on peripheral nerve conduction in vivo and in vitro. METHODS: The in vivo neurotoxicity was tested on rat sciatic nerve by intraneural injection of the uraemic concentrate, followed, 1 to 6 days later, by electrophysiological assessment of motor response and maximum conduction velocity. In vitro experiments were performed on isolated frog sciatic nerve in the presence of uraemic concentrate, and the neurotoxicity was evaluated from the rate of the decrease in the amplitude of the evoked maximal action potential. RESULTS: In the in vivo experiments, the sciatic nerves injected with the uraemic concentrate showed a decrease in maximum conduction velocity and a progressive impairment in evoked motor response. In the in vitro experiments uraemic concentrate induced a dose-dependent neurotoxic effect. CONCLUSIONS: Our study demonstrates the presence in plasma of uraemic patients of a compound of 2-60 kDa MW with neurotoxic activity.

Within the frame of an anthropobiological survey on some populations of Cameroon (1985-1991), Hb beta data were collected from numerous ethnic groups including Bakaka, Bamileke, Daba, Fali, Guiziga, Kanuri, Mada, Mafa, Mundang, Uldeme, Podokwo, Tali, Tupuri, Fulbe, Mandara, Ewondo and Bassa. Hb beta *S allele frequencies ranged from 0.008 +/- 0.003 (among Fali) to 0.152 +/- 0.020 (among Mandara) and 0.152 +/- 0.044 (among Podokwo), whereas Hb beta *S was found to be absent among Tupuri. Hb beta *C was observed among Bamileke (0.001 +/- 0.001), Fali (0.003 +/- 0.002), Fulbe (0.002 +/- 0.002), Mafa (0.005 +/- 0.005), Mundang (0.005 +/- 0.005), Tupuri (0.010 +/- 0.007) and Podokwo (0.015 +/- 0.015). The possible reasons for these variations in allele frequencies are discussed.

Bakakas are native Bantus belonging to the Mbo-Bakossi group, peopling the Cameroon's Littoral region. In the context of a wide bio-anthropological study project focused on the bio-historical processes involved in the areas, 278 adults of both sexes from the villages of Ebone and Bakwat (Bakaka Canton) were investigated for 14 erythrocyte and serum genetic polymorphisms (ACP1, ADA, EsD, GLO, Hb beta, GPX1, CAII, PGM1, SAHH, 6-PGD, Hp, Pi, Gc and Tf). With only a few exceptions (Hp and GLO systems), the genetic frequencies of the polymorphisms considered tend to fall within the range of variation known for the subsaharan populations. With reference to the malaria endemicity characterizing the Littoral environment, high frequencies for Hb beta*S allele and absence of the ACP1*R 'Negro allele' were recorded. The genetic distances among Bakakas and 14 other Central African populations were also calculated from six genetic loci.

Microfilter absorbed whole blood samples from 223 Tanzanian babies and 189 adults from Cameroon have been examined. Blood specimens are difficult to obtain from African suburban and rural areas, and lack of storage and transportation facilities can prevent the collection of samples. We evaluated some microassays employing whole blood collected on filter paper. This method is a well established technique in neonatal screening for endocrinometabolic diseases. We also developed microassays for whole dried blood spots to type AB0 blood groups and HIV disease using commercial reagents. Phenotype and gene frequencies for AB0 and hemoglobin systems as well as our results concerning the typings of thyroxine (T4), thyroid stimulating hormone (TSH), human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are reported.

Four different unusual 6-phosphogluconate dehydrogenase (6-PGD) electrophoretic patterns found among the Italian (Rome), Bamileke (Cameroon), and North Bateke and Babenga Pygmy (Congo) populations are described.

The authors present their first results with the treatment of hemifacial spasm by controlled percutaneous thermocoagulation of the facial nerve. Seven patients have been treated to date with good immediate results on the movements, although a slight paresis of the homolateral facial musculature, aesthetically acceptable, persists after treatment. A long-term follow-up at more than 10 months was achieved in only 3 patients, who showed a complete regression of the spasm with partial disappearance of the facial hemiparesis.