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Biomedical subjects

E Coto

Publications and source records attributed to E Coto.

17 recordsLinked to original sources
PubMed1992

[Diagnosis of dominant renal polycystosis in adults by analysis of DNA polymorphism].

BACKGROUND: Adult renal polycystosis (ARP) is a dominant autosomic disease. The gene responsible for this disease in most families has been located on the short arm of chromosome 16 (16 p) by restriction analysis of the DNA polymorphisms (RFLP). METHODS: The existence of several polymorphic markers flanking this gene permits the diagnosis of any member of an affected family. A series of proximal and distal genetic markers have been used to study the segregation of the disease in a group of families with more than one affected member. RESULTS: The clinical and genetic results obtained from a study of 10 Spanish families with ARP have been reported. A high percentage of the members under 30 years of age (40%) did not present renal cysts. CONCLUSIONS: Restriction analysis of DNA are fundamentally for a disease in which a high percentage of carriers remain asymptomatic within the reproductive age.

Adult↗
PubMed1992

Molecular typing of HLA-B27 alleles.

HLA-B27 represents a family of closely related antigens. Six alleles which differ in a limited number of nucleotide substitutions have been described (B*2701--B*2706). These changes are clustered in alpha 1 and alpha 2 domains. Polymerase chain reaction strategies were designed to amplify specific regions of class I exons 2 and 3. Amplified sequences were tested with eight sequence-specific oligonucleotides to distinguish all B27 subtypes. We also subtyped B27 in 50 healthy Spanish individuals using this procedure. The B*2705 subtype is over-represented in our population (96%). The remaining 4% carried the B*2702 allele. This finding is in agreement with the frequencies described by other techniques (cytotoxic T lymphocytes and isoelectric-focusing) for Caucasian populations. Class I oligotyping is a poorly developed field with significant potential applications. This procedure of genotyping B27 alleles is a reliable method which can be used in transplantation and B27-associated disease studies.

Alleles↗
PubMed1992

Analysis of ras oncogene mutations in human squamous cell carcinoma of the head and neck.

The presence of proto-oncogene mutations at codons 12, 13 and 61 of the Ha-, Ki-, and N-ras in primary head and neck squamous cell carcinoma are analysed in this study. Oncogene ras-specific sequences were amplified by the polymerase chain reaction and probed with mutation specific oligonucleotide probes. Mutations were detected in 8 of 22 samples (36.3%). No mutations were detected on patients' peripheral blood DNA. We found that histologically and clinically, squamous cell carcinomas with or without a ras mutation do not differ significantly from each other.

Carcinoma, Squamous Cell↗
PubMed1992

Genetic and clinical studies in autosomal dominant polycystic kidney disease type 1 (ADPKD1).

Thirteen Spanish families with autosomal dominant polycystic kidney disease were studied. In one family the disease did not segregate with polymorphic markers around the PKD1 locus. All subjects over the age of 30 years carrying a mutation at the PKD1 locus showed renal ultrasonographic cysts, but 40% of carriers of the PKD1 mutation younger than 30 years did not have renal cysts. Hypertension was found to be more frequent in those with renal cysts. Recombinants between 16p polymorphic loci and the PKD1 locus are described.

Adult↗
PubMed1991

Rapid genetic analysis of families with polycystic kidney disease 1 by means of a microsatellite marker.

Presymptomatic diagnosis of polycystic kidney disease 1 (PKD1) is possible by genetic linkage analysis with markers from both sides of the disease locus. The existing proximal markers are not informative in many families, so such analysis is difficult and time-consuming. We sought more useful length polymorphisms on the proximal side of the locus among simple sequence repeats (microsatellites). We identified two microsatellite polymorphisms that lie closer to the PKD1 locus than any previously described highly variable marker. One, SM7, is especially informative; we have found fourteen alleles and the observed heterozygosity in caucasians is 62.7%. Genetic linkage analysis in PKD1 families suggests that both of the markers lie proximal to the disease gene, closer than existing flanking markers. These polymorphisms can be simply assayed by polymerase chain reaction amplification of the variable regions, which generates DNA fragments that can be separated on non-denaturing acrylamide gels and directly examined after gel staining. This rapid, inexpensive, and non-radioactive method of linkage analysis allows the complete study of DNA samples within 8 h.

Alleles↗
PubMed1991

DNA polymorphisms and linkage relationship of the human complement component C6, C7, and C9 genes.

In this report we describe the linkage between genes encoding human complement components C6, C7, and C9. Polymorphisms have been described at the DNA level for the C7 and C9 genes. We have studied 20 individuals by Southern blot analysis with four C6 cDNA subclones to detect restriction fragment length polymorphisms (RFLPs). We have found a Taq I polymorphism defined by two alleles of 8.0 (C6 H) and 6.0 (C6 L) kilobases (kb). RFLP segregation for the C6, C7, and C9 loci in informative families allowed us to estimate the maximum Lod scores at a recombination fraction of theta = 0.0 (C6-C7), theta = 0.0 (C7-C9), and theta = 0.0 (C6-C9). Significant linkage disequilibrium was found between C6 and C7 and between C7 and C9 loci in directly determined haplotypes of unrelated parents. Data from this study show that the genes encoding the human terminal complement components C6, C7, and C9 define a cluster in the short arm of chromosome 5. We propose that the clusters involving the C8A and C8B and the C6, C7, and C9 genes be referred to as MACI and MACII, respectively.

Chromosome Mapping↗
PubMed1991

DNA analysis of HLA-DR4B1 subtypes in multiple sclerosis by specific oligonucleotide probes.

Conversely to the well-established association of DR2/Dw2 with multiple sclerosis (MS) susceptibility in Caucasoids, several studies have found an association of DR4 in populations from Mediterranean origin. We have studied the distribution of the different DR4B1 subtypes in Spanish MS patients. Oligonucleotide probes were selected in order to type samples amplified by polymerase chain reaction (PCR) from Spanish DR4+ MS patients (25) and controls (28). No DR4B1 subtypes were found to be increased in MS. MS susceptibility linked to DR4 may be due to the presence of shared functional epitopes common to the different HLA-DR4B1 subtypes.

Amino Acid Sequence↗
PubMed1991

Germline repertoire of T-cell receptor beta-chain genes in patients with insulin-dependent diabetes mellitus.

We have investigated the genotype and allelic distribution of germline restriction fragment length polymorphisms of the T-cell receptor beta chain, segment C beta, and two variable segments which are in linkage disequilibrium, V beta 8 and V beta 11, in 42 insulin-dependent diabetes mellitus (IDDM) patients and in 51 healthy blood donors used as controls. Recently, several works have reported contradictory results showing or not showing an association between polymorphic alleles of the C beta gene and diabetes type I. We found no significant differences in the allele, genotype, and haplotype distribution of the gene segments studied, between IDDM patients and control populations.

Adolescent↗
PubMed1991

[Use of the plasma coagulation method for ultrastructural analysis of biological specimens].

Biological particulate specimens, including Saccharomyces cerevisiae yeast, bovine spermatozoa and human blood cells (normal erythrocytes and leukemic cells) were processed for scanning and transmission electron microscopy using the coagulated plasma technique. The specimens were suspended in frozen and thawed plasma; later, coagulation was induced by adding CaCl2. The clot was cut into small pieces and processed as tissue fragments. The technique is an useful tool when processing biological particulate specimens for electron microscopy.

Animals↗
PubMed1990

DNA polymorphism of the human complement component C7 gene in familial deficiencies.

A C7 cDNA probe detecting a TaqI restriction fragment length polymorphism has been used to examine the segregation of the "silent allele" (C7*Q0) in two familial deficiencies. Carrier diagnosis in healthy children is possible when both parents are heterozygotes. Only one of these two families was informative. The "silent allele" is linked to different TaqI alleles in both families. This suggests that at least two different C7*Q0 alleles are present in our population. This paper gives a protocol for genetic studies of hereditary traits in which the C7 gene and other genes tightly linked to it are involved.

Alleles↗
PubMed1990

HLA antigens in psoriatic arthritis subtypes of a Spanish population.

HLA-A, B, and C antigens were studied in 104 Spanish patients with psoriatic arthritis. Different clinical features were evaluated and the patients divided into disease subsets. HLA-B17, B27, B16, and Cw6 were the most common haplotypes in the total group. The HLA-B17/Cw6 haplotype was increased in patients with oligoarthritis. The increase of antigen B17 correlated with oligoarthritis and spondarthritis, whereas Cw6 was more significant in oligoarthritis. The prevalence of the B27/Cw1 haplotype was greater in association with spondarthritis and was probably related to the B27.5 subtype linked to Cw1. A significant negative association between the B44/Cw5 haplotype and psoriatic arthritis was found. The existence of several haplotypic factors in the different subsets is discussed. Lack of one or more HLA factors is thought to be responsible for the different clinical forms of psoriatic arthritis.

Arthritis, Psoriatic↗
PubMed1990

HLA antigens in multiple sclerosis of northern Spanish population.

HLA-A, -B, -C, -DR, -DQ antigens were studied in 43 multiple sclerosis (MS) patients with clinically definite remittent sclerosis from Asturias (North Spain). The prevalence of HLA-B7, B7 and B27 were significantly increased in MS. HLA-B35 was under-represented in these patients. DR2 was increased but not significantly. No association with DQw1 was discovered. The existence of several susceptibility factors in the more common B7/DR2/DQw1 haplotype is discussed.

Gene Frequency↗
PubMed1990

Study of genetic polymorphism of seventh complement component in two families with hereditary deficit.

The results of an allelic segregation of C6 and C7 were studied in two Spanish families that have members with C7 deficiency. Absence of C7 in the affected siblings and half of the normal values in their parents were found in both families. The variant responsible for the deficiency (C7Q*0) follows a codominant autosomic inheritance pattern. Establishing allotypes of C6 and C7 by isoelectrofocusing followed by electrophoretic immunoblotting allowed haplotype assignments. In both families the haplotype form responsible for the deficiency seemed to be related to the C6B allotype.

Alleles↗