Distribution of HLA and haplotypes of Colombian and Jamaican black populations

To investigate the genetic background of the black populations of Colombia and Jamaica, we determined HLA types of 78 Colombian and 98 Jamaican blacks from 2 different socioeconomic groups (Jamaican #1 and Jamaican #2) and estimated the frequencies of HLA genes and haplotypes. A phylogenetic tree based on the HLA gene frequencies revealed that Jamaican #1 and Jamaican #2 were distinct from each other, Jamaican #1 being closely related to Colombian blacks and the Jamaican #2 being closely related to Senegalese and Zairean populations. Three-locus haplotypes of Colombian and Jamaican #1 blacks were an admixture between Africans and Caucasians or South American Indians while Jamaican #2 blacks were relatively homogeneous and appeared to conserve African lineages. The major five-locus HLA haplotypes were not shared among Colombian, Jamaican #1 and Jamaican #2 blacks. These results indicated that the black populations of Colombia and Jamaica were originated from African blacks and admixed variably with Caucasians and South Americans Indians to make genetic subpopulations in Colombia and Jamaica. (AU)

Intrathecal synthesis of antibodies to human T lymphotropic virus type I and the presence of IgG oligoclonal bands in the cerebrospinal fluid of patients with endemic tropical spastic paraparesis

Tropical spastic paraparesis (TSP), a neuromyelopathy predominantly involving the pyramidal tract and commonly observed in tropical and equatorial areas, was recently found to be associated with human T lymphotropic virus type I (HTLV-I). We investigated sera and cerebrospinal fluid (CSF) from 19 patients with TSP who were from the Caribbean area, French Guiana, and Africa. Our results showed an elevated intra-blood-brain barrier IgG synthesis rate and an elevated IgG index, with an increased HTLV-I antibody-to-albumin ratio and the presence of CSF oligoclonal bands in the majority of the patients. These data, in association with similar HTLV-I antibody patterns between patients with TSP who were from these three regions, strenghten the probable etiologic role of HTLV-I in the pathogenesis of such chronic neuromyelopathies. (AU)

Dental manpower requirements in emerging countries

The training and use of dental auxiliaries in newly emerging countries are proposed as the solution in such countries to the prevalence of dental disease, the paucity of professional dentists and dental schools, and the competing demands on their economies. Statistically valid dental health surveys of many countries do not exist, but scattered evidence from Jamaica, Guatemala, Thialand, Senegal, and Kenya, among others, indicates that caries and periodontal infections are widespread, and malocclusion, malignant neoplasms of the mouth, and calcium defects are not infrequent. The ratio of dentists to population varies from 1 to 15,000 in Jamaica to 1 to 250,000 in Kenya. Only 130 to 150 dentists are gratuated each year from Africa's seven dental schools; half the countries of the world have no dental school and no prospects of attaining one. The cost of producing one professional dentist is prohibitive - $23,000 per dentist in Guatemala, for example. Auxiliaries can fulfil many basic dental needs of both children and adults in these countries. A program with three consecutive but overlapping phases is suggested. Phase one is to produce a small corps of superbly trained dentists. Phase two is to supplement this corps by giving existing paramedical and auxiliary health personnel 6 weeks of practical chairside training to develop specific cadres of trained dental auxiliaries. Single skill auxiliaries can be trained in 2 years. A dental surgeon and six auxiliaries can serve an estimated 25,000 persons. Multiple skill auxiliaries with 8 years of general education need 3 years of technical training, preferably in an institution where graduate dentists and dental hygienists are also prepared. The auxiliary's role is both as assistant to the dentist and, where supervision is remote, as his substitute. Producing two types of auxiliaries, one oriented to the dental care of children, and the second a curative care of adults, would permit the organization of dental health services on a rational priority basis. (Summary)