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Biomedical subjects

D Ramon

Publications and source records attributed to D Ramon.

18 recordsLinked to original sources
PubMed2002

Complete cDNA sequences of the HLA-DRB1*14011, *1402, *1403 and *1404 alleles.

Sequencing studies of HLA class II molecules have been focused almost exclusively on the highly polymorphic exon 2. In this study the complete cDNA sequence of four alleles of the DR14 lineage (DR52 group) are reported for the first time. The HLA-DRB1*1402 and *1403 sequences were shown to be identical to the previously determined DRB1*13011 sequence, also of the DR52 group, in exons 1, 3, 4, 5 and 6. HLA-DRB1*14011 and *1404 were identical to DRB1*13011 in exons 1, 4, 5 and 6 sequences while they showed specific features within their exon 3 sequence. Both alleles showed a synonymous substitution at the third base of codon 114. However, DRB1*14011 also has a non-synonymous substitution at the first base of codon 112 which results in a histidine to tyrosine substitution. This is a novel substitution as Histidine 112 is conserved in all known HLA class II B genes.

Alleles↗
PubMed2002

Complete cDNA sequences of the HLA-DRB1*0402 and DRB1*11041 alleles.

Since the development of the polymerase chain reaction, most HLA class II allele sequencing has been exclusively focused on the highly polymorphic exon 2. We present here the full cDNA sequences of two HLA-DRB1 alleles, DRB1*0402 and DRB1*11041, both of which were previously only available as partial sequences. HLA-DRB1*11041 was found to be completely homologous to DRB1*11011 in exons 1, 3, 4, 5 and 6 and HLA-DRB1*0402 was found to be identical to DRB1*04011 in exons 1, 3, 4, 5 and 6.

Alleles↗
PubMed2001

HLA class I diversity in Kolla Amerindians.

Human leukocyte antigen (HLA) class I polymorphism was studied within a population of 70 unrelated Kolla Amerindians from the far northwest of Argentina close to the Bolivian border. The results indicate that the HLA-A, -B, and -C alleles typical of other Amerindian populations also predominate in the Kolla. These alleles belong to the following allele groups: HLA-A*02, *68, *31, *24, HLA-B*35, *15, *51, *39, *40, *48, and Cw*01, *03, *04, *07, *08, and *15. For the HLA-A locus, heterogeneity was seen for HLA-A*02 with A*0201, *0211, and *0222; and for A*68 with *68012 and *6817, the latter being a novel allele identified in this population. Analysis of HLA-B identified heterogeneity for all Amerindian allele groups except HLA-B*48, including the identification of the novel B*5113 allele. For HLA-C heterogeneity was identified within the Cw*07, *04, and *08 groups with Cw*0701/06, *0702, *04011, *0404, *0803, and *0809 identified. The most frequent "probable" haplotype found in this population was B*3505-Cw*04011. This study supports previous studies, which demonstrate increased diversity at HLA-B compared with HLA-A and -C. The polymorphism identified within the Kolla HLA-A, -B, and -C alleles supports the hypothesis that HLA evolution is subject to positive selection for diversity within the peptide binding site.

Alleles↗
PubMed2000

HLA-A*6817, identified in the Kolla Amerindians of North-West Argentina possesses a novel nucleotide substitution.

Analysis of HLA polymorphism of the indigenous populations of Central and South America has identified many alleles not seen previously in other populations. We have described a novel allele, B*5113, previously in a Kolla Amerindian individual from North-West Argentina. Here we present a second novel allele from this population: A*6817, which differs from its closest neighbour A*68012 by a single substitution at nucleotide 419. This substitution of adenosine 419 A*68012 for thymidine in A*6817 results in a novel amino acid change (aspartate to valine) at residue 116.

Argentina↗
PubMed1995

Construction of a recombinant wine yeast strain expressing a fungal pectate lyase gene.

A gene fusion between the Saccharomyces cerevisiae actin gene promoter and the cDNA of the Fusarium solani f. sp. pisi pelA gene has been constructed. This expression cassette has been introduced into the industrial wine yeast strain T73. The resulting recombinant strain is able to secrete active PELA enzyme into the culture medium. In preliminary microvinification experiments the wine produced by this pectinolytic strain is indistinguishable from wine produced using the non-transformed strain on the basis of the chemical analyses. Large scale fermentations need to be carried out in order to assess the effects on filtrability.

Base Sequence↗
PubMed1989

Transformation of the dermatophyte Trichophyton mentagrophytes to hygromycin B resistance.

A transformation system for the ringworm-producing dermatophyte Trichophyton mentagrophytes has been developed. The system employs the plasmid pHIS, which contains a bacterial hygromycin B phosphotransferase gene linked to Cochliobolus heterostrophus regulatory sequences (B. G. Turgeon, R. C. Garber, and O. C. Yoder, Mol. Cell. Biol. 7:3297-3305, 1987). This plasmid confers hygromycin B resistance to T. mentagrophytes. The DNA was stably integrated into the fungal genome, and the number and sites of integrations varied among transformants. Transformant clones were capable of infecting guinea pigs. This system opens the way for the molecular genetic analysis of the interaction of T. mentagrophytes with epithelial animal tissues.

Animals↗
PubMed1988

Onychopathy in a patient with fetal hydantoin syndrome.

Hydantoin is an anticonvulsant drug with several side effects. A teratogenic potential has been suggested. The fetal hydantoin syndrome is an entity that consists of a broad range of morphologic and developmental disorders in children born of epileptic mothers exposed to hydantoin during pregnancy. We treated a girl in whom onychopathy was a monosymptomatic or mild form of this syndrome.

Epilepsy↗
PubMedDate not supplied

Eccrine angiomatous hamartoma: report of three patients.

Eccrine angiomatous hamartoma is a rare, benign entity. The histologic features include proliferation of eccrine sweat glands and angiomatous capillary channels. We report three children who each had a single lesion on a limb. These lesions were clinically angiomatous, and we obtained the diagnosis by histologic and immunohistochemical studies.

Capillaries↗