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Biomedical subjects

A Roses

Publications and source records attributed to A Roses.

15 recordsLinked to original sources
PubMed2000

A microsphere-based assay for multiplexed single nucleotide polymorphism analysis using single base chain extension.

A rapid, high throughput readout for single-nucleotide polymorphism (SNP) analysis was developed employing single base chain extension and cytometric analysis of an array of fluorescent microspheres. An array of fluorescent microspheres was coupled with uniquely identifying sequences, termed complementary ZipCodes (cZipCodes), which allowed for multiplexing possibilities. For a given assay, querying a polymorphic base involved extending an oligonucleotide containing both a ZipCode and a SNP-specific sequence with a DNA polymerase and a pair of fluoresceinated dideoxynucleotides. To capture the reaction products for analysis, the ZipCode portion of the oligonucleotide was hybridized with its cZipCodes on the microsphere. Flow cytometry was used for microsphere decoding and SNP typing by detecting the fluorescein label captured on the microspheres. In addition to multiplexing capability, the ZipCode system allows multiple sets of SNPs to be analyzed by a limited set of cZipCode-attached microspheres. A standard set of non-cross reactive ZipCodes was established experimentally and the accuracy of the system was validated by comparison with genotypes determined by other technologies. From a total of 58 SNPs, 55 SNPs were successfully analyzed in the first pass using this assay format and all 181 genotypes across the 55 SNPs were correct. These data demonstrate that the microsphere-based single base chain extension (SBCE) method is a sensitive and reliable assay. It can be readily adapted to an automated, high-throughput genotyping system. [Primer sequences used in this study are available as online supplementary materials at www.genome.org.]

DNA, Complementary↗
PubMed1998

A 4-Mb high-density single nucleotide polymorphism-based map around human APOE.

Whole-genome association studies using single-nucleotide polymorphisms (SNPs) are the proposed method of choice for the identification of loci associated with complex diseases. In this report, we address the feasibility of generating high-density SNP maps (with <100-kb spacing). As a pilot study, we concentrated on a 4-Mb region around the human APOE locus on chromosome 19. We compared the efficiency of SNP detection using YAC-based versus BAC/PAC-based maps, sequencing individual DNAs versus a pooled DNA sample, and we evaluated three different software applications for polymorphism detection. A total of 121 SNPs (25 in coding regions) were identified. The frequency of SNP detection was 1 SNP/1.1 kb of genomic sequence. From APOE to CALM3 (approximately 2 Mb), the average marker spacing was approximately 30 kb. Fifty-one SNPs were genotyped in five populations, and 10 SNPs showed an allele frequency differential greater than 0.5 between populations. Our results demonstrated that high-density SNP maps can be efficiently generated using existing technologies and that a genome-wide map with 60,000-100,000 SNPs is achievable in a reasonable time frame.

Alleles↗
PubMed1997

Workshop on schizophrenia.

On November 29-30, 1995, the National Academy of Sciences and the Institute of Medicine brought together experts in schizophrenia and specialists in other areas of the biological sciences in a workshop aimed at promoting the application of the latest biological information to this clinical problem. The workshop paid particular attention to evidence of pathology in the brains of people with schizophrenia, and to the possibility that this reflects an abnormality in brain development that eventually leads to the appearance of symptoms. The participants were impressed with the complexity of the problem, and felt that multiple approaches would be required to understand this disease. They recommended that a major focus should be on the search for predisposing genes, but that there should be parallel research in many other areas.

Brain↗
PubMed1996

Polymorphism and chromosomal localization of the GI-form of human glutathione peroxidase (GPX2) on 14q24.1 by in situ hybridization.

We have isolated a 3.3-kb DNA containing the two exons and a 2.6-kb intron of the human CPX2 gene. This gene encodes the intestinal isoenzyme of glutathione peroxidase, GSHPx-GI. Consistent signals were detected at 14q24.1 when this DNA was used as a probe for fluorescence in situ hybridization on metaphase chromosomes. Based on either single-stranded conformation polymorphism or sequencing analysis, two sites containing DNA polymorphism were found in the intron: the 5' end had a single A/T alteration, and the 3' end had a microsatellite of TC repeats.

Amino Acid Sequence↗
PubMed1993

North Carolina macular dystrophy (MCDR1). A review and refined mapping to 6q14-q16.2.

The macular degenerations comprise a heterogeneous group of diseases, generally reported in small families. Single, large family studies of North Carolina macular dystrophy have aided in defining the spectrum of the phenotype of this disorder and its relationship to other macular degenerations. North Carolina macular dystrophy has many phenotypic similarities to age-related macular degeneration with the glaring exception of the early age of onset of North Carolina macular dystrophy. The authors initially reported mapping this disease by linkage to the long arm of chromosome 6. They now report additional data on a total of 247 individuals in the original North Carolina macular dystrophy family whom we ascertained for clinical and molecular genetic studies. Standard clinical ophthalmic examination revealed that 96 of these individuals were affected. Molecular genetic studies increased the LOD score to 23 and refined the genomic localization of the disease-causing gene to 6q14-q16.2.

Adult↗
PubMed1992

North Carolina macular dystrophy is assigned to chromosome 6.

North Carolina macular dystrophy (NCMD) is an autosomal dominant macular dystrophy causing impaired central vision at an early age, is completely penetrant, and is present in a single large family. With the development of the hypervariable microsatellite (CA repeats) markers in the human genome, it was possible to relatively rapidly screen most of the genome for linkage to the NCMD gene. After utilizing 124 genetic markers, which excluded over 95% of the human genome, three Marshfield microsatellites located at 6q13-q21 were linked to the NCMD locus. Marshfield marker (MFD) 131 gave a lod score of Z(theta) = 4.36 at theta = 0.137; MFD 171 gave a Z(theta) = 8.42 at theta = 0.004; and MFD 97 gave a Z(theta) = 13.10 at theta = 0.017. Other retinal diseases have been reported on 6q stressing the importance of this region and possibly suggesting that these diseases may be allelic or located in part of a large macular gene family. Locating and characterizing the NCMD gene may be an important step in understanding this group of maculopathies as well as age-related macular degeneration (AMD), a common cause of blindness in the elderly.

Adult↗
PubMed1992

Genetic evidence for a novel familial Alzheimer's disease locus on chromosome 14.

Familial Alzheimer's disease (FAD) has been shown to be genetically heterogeneous, with a very small proportion of early onset pedigrees being associated with mutations in the amyloid precursor protein (APP) gene on chromosome 21, and some late onset pedigrees showing associations with markers on chromosome 19. We now provide evidence for a major early onset FAD locus on the long arm of chromosome 14 near the markers D14S43 and D14S53 (multipoint lod score z = 23.4) and suggest that the inheritance of FAD may be more complex than had initially been suspected.

Aged↗
PubMed1991

North Carolina macular dystrophy: exclusion map using RFLPs and microsatellites.

The autosomal dominant macular dystrophies are a confusing group of poorly understood diseases. Linkage studies will greatly aid our classification of these disorders and hopefully provide insight into central retinal function and dysfunction such as occurs in age-related macular degeneration. North Carolina macular dystrophy is one such disease that has been amenable to linkage analysis because of the large pedigree size. Seventy-six polymorphic markers have been tested for linkage and exclusion data are presented.

Chromosome Mapping↗
PubMed1988

Segregation of linked probes to myotonic dystrophy in a family demonstrating that 152 and APOC2 are on the same side of DM on 19q.

The two markers most closely linked to the myotonic dystrophy (DM) locus on chromosome 19 are the gene that codes for apolipoprotein CII (APOC2) and the anonymous probe D19S19 (LDR152). Both of these markers show tight linkage to DM, with maximum lod scores of greater than 20 at recombination fractions of less than 0.05. We have identified, in a family in which DM segregates, an affected individual where a meiotic recombination event has occurred in which both of these linked markers have crossed over with the gene defect. This demonstrates that APOC2 and D19S19 are probably on the same side of DM.

Chromosome Mapping↗
PubMed1988

The maternal-infant center in the control of hepatitis B.

A seroepidemiologic survey of HBV infection was carried out in four population groups served by the Maternity Hospital of Majorca, an island in the Mediterranean. The prevalence of HBV markers (HBsAg, anti-HBs, anti-HBc), determined by enzyme-immunoassay, reached 17.2% among 864 parturients, 17.2% in 783 hospital personnel, 2.7% and 19.2% among the 186 children and 73 husbands of parturients with no HBV markers, 22.8% and 43.8%, respectively, among the 44 children and 48 husbands of HBsAg chronic carrier parturients. The prevalences of HBsAg in the same groups reached 0.9%, 1.5%, 0% and 0%, 11.4% and 2.1%, respectively. The carrier state represents 50% of all infection cases among children and 4.8% among husbands of carrier women. The prevalence of markers, which was especially high among personnel working in maintenance services (39.1%), on surgical wards (35.3%), among midwives (27.6%) and in cleaning and laundry services (27.1%), and laboratories (21.4%), is used as an indicator in defining priorities for the vaccination of people at risk. Sixty-seven newborn babies of HBsAg carrier mothers were administered one dose of HBIG and three doses of hepatitis B vaccine; at 12 months of age, the seroconversion rate was 98.5%, whereas 1 child (1.5%) became a chronic carrier. Maternity hospitals represent the ideal centers in which to carry out the detection of HBsAg in pregnant women prior to parturition, to ensure that all newborns of chronic carrier women receive passive-active immunization, and to screen their family contacts and vaccinate those who are found susceptible to the infection.

Adult↗
PubMed1978

Thymolipoma in association with myasthenia gravis.

A patient with a 100-g thymolipoma and myasthenia gravis experienced marked improvement in neuromuscular symptoms following removal of the tumor. Although 60 examples of thymolipoma have been reported, we believe that this is the first example of this tumor associated with myasthenia gravis. The clinical, radiologic, and histopathologic manifestations of previously reported cases of thymolipoma are discussed in relation to our patient's case.

Humans↗