Evolution of human papillomavirus type 18: an ancient phylogenetic root in Africa and intratype diversity reflect coevolution with human ethnic groups.

Papillomaviruses are an ideal model system for the study of DNA virus evolution. On several levels, phylogenetic trees of papillomaviruses reflect the relationship of their hosts. Papillomaviruses isolated from remotely related vertebrates form major branches. One branch of human papillomaviruses (HPVs) includes an ape and two monkey papillomaviruses, possibly because the diversification of the viruses predated the separation of the infected-primate taxa. This hypothesis predicts that the root of the evolution of some if not all HPV types should point to Africa, since humans evolved from nonhuman primates in this continent. We tested this hypothesis and compared the genomic sequences of HPV type 18 (HPV-18) isolates from four continents. Diversity within HPV-18 correlates with patterns of the evolution and spread of Homo sapiens: HPV-18 variants, just like HPV-16 variants, are specific for the major human races, with maximal diversity in Africa. Outgroup rooting of the HPV-18 tree against HPV-45, which is closely related to HPV-18, identifies African HPV-18 variants at the root of the tree. The identification of an African HPV-45 isolate further reduces the evolutionary distance between HPV-18 and HPV-45. HPV-18 variants from Amazonian Indians are the closest relatives to those from Japanese and Chinese patients and suggest that a single point mutation in the phylogenetically evaluated genomic segment represents at least 12,000 years of evolution. We estimate that diversity within HPV-18 and probably within other HPV types evolved over a period of more than 200,000 years and that diversity between HPV types evolved over several million years.

Care strategies for schizophrenic patients in a transcultural comparison.

This study was conducted in order to test the hypothesis derived from the International Pilot Study of Schizophrenia (IPSS) that the existence of extended families in developing countries contributes to the more favorable course and outcome of schizophrenia in these countries in comparison with industrial countries. For this purpose, we compared data from the 5- and 10-year follow-up obtained within the IPSS at Cali, Colombia with data from two 5- to 8-year follow-up studies of former schizophrenic inpatients of the Max Planck Institute of Psychiatry (MPIP) in Munich, FRG. Although, in Cali, schizophrenics are hospitalized and treated with drugs only during acute episodes of the psychosis and no facilities exist for long-term treatment, the psychopathological outcome was, on the whole, not worse than in Munich. Furthermore, the duration of hospitalization during the follow-up period was much lower at Cali and a significantly lower number of Colombian than of German patients was not separated from their families. However, contrary to the hypothesis, family size did not predict course and outcome at both centers.