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Biomedical subjects

P L Yu

Publications and source records attributed to P L Yu.

At least 91 records · Page 5Linked to original sources
PubMed1981

Carrier detection in Sanfilippo syndrome type B: report of six families.

Serum samples from 175 individuals in six Sanfilippo syndrome type B (SFB) families and 360 White controls were assayed for serum alpha-N-acetyl-D-glucosaminidase (NAG) activity. Only minimal overlap was observed between the controls' NAG activity distribution and that of the 12 obligate heterozygotes. The distribution of NAG activity was log transformed to reduce skewness, and segregation of family members with a prior risk of being a SFB carrier was well within expected limits. However, in one consanguineous family the NAG activity of both parents of one SFB obligate heterozygote was within the normal range for NAG activity. Plausible explanations for this finding are discussed. Additionally, the serum NAG activity of one control and her mother were found to lie within one standard deviation of the obligate heterozygote mean. These individuals are most probably carriers for SFB.

Acetylglucosaminidase↗
PubMed1980

Evidence of genetic variation for alpha-N-acetyl-D-glucosaminidase in black and white populations: a new polymorphism.

Serum and/or plasma samples from 360 Whites and 126 Blacks were assayed for activity of the lysosomal hydrolase alpha-N-acetyl-D-glucosaminidase (NAG). The samples from the Blacks had an increased mean (0.50 nm/ml/min) and standard deviation (0.30 nm/ml/min) compared to those from the Whites (0.29 nm/ml/min and 0.10 nm/ml/min, respectively). After loge transformation and admixture analysis, it was possible to demonstrate the presence of 3 distributions of NAG activity in Blacks and at least 2 in Whites. Segregation analysis of the NAG activity of 29 White half-sib twin families indicated that a genetic model for the inheritance of NAG activity provided a better fit (P less than 0.01) with the data than the "environmental" model. Thus, the study suggests the presence of a genetic polymorphism for NAG activity in Black and White populations. The presence of alleles for high and low NAG activity in the normal population could lead to incorrect interpretation of serum carrier tests for Sanfilippo syndrome, type B.

Acetylglucosaminidase↗
PubMed1980

Heritable salivary proteins and dental disease.

A sample consisting of 92 black subjects was examined in this study. According to results of preliminary statistical tests there is a significant relationship between certain genetically determined salivary factors and individual susceptibility to dental disease in the racial group studied. These findings are been validated by the examination of data from several additional studies involving large samples.

Age Factors↗
PubMed1980

Linkage relationships and multipoint mapping of the human parotid salivary proteins (Pr, Pa, Db).

Based on data from 76 informative families, linkages between Pa and Pr and between Pr and Db have been established by two-point linkage analysis. In both pairs of loci, there were no significant sex heterogeneity in recombination fractions. Linkage between Pa and Db cannot be established based on two-point analyses, but a significant sex difference in the recombination fraction between Pa and Db was observed. Strong confirming evidence was obtained from three-point analysis to place Pa, Pr, and Db in one linkage group. The most likely order is Pa-Pr-Db, but the relative odds over second order Pr-Pa-Db are small. Haplotype frequencies of Pr, Pa, and Db were obtained based on the phenotypes of the 685 random Caucasians, providing evidence for marked linkage disequilibrium among the three loci.

Chromosome Mapping↗
PubMed1979

Urinary pepsinogen isozymes: a highly polymorphic locus in man.

A genetic analysis of human urinary pepsinogen isozymes is presented. Nine discrete phenotypes were identified in a population survey of 215 unrelated Caucasian individuals. The phenotypes were characterized by differences among the staining intensities of the activated group I pepsinogens, Pg 5, Pg 4, Pg 3, and Pg 2. The genetic studies demonstrated that the codominant expression of four alleles, PgA, PgB, PgC and PgD, at a single genetic locus determined the nine phenotypes identified. Linkage analysis excluded close linkage of the Pg locus with the chromosome 6 markers HLA, GLO1, and Bf.

Genetic Linkage↗
PubMed1978

Is partial anodontia a syndrome of Black Americans?

A study was designed to test the prevalence of congenitally missing permanent teeth in two Black American samples of children, ages 3-18. When combined, male with female, and compared with the Caucasian sample, the incidence of congenital absence is 2.57% and 5.15% for Caucasians.

Adolescent↗
PubMed1977

A genetic study of erythrocyte arginine-tRNA synthetase activity in man.

To search for evidence of genetic variation among the aminoacyl-tRNA synthetases, a semi-automated assay procedure employing a Technicon AutoAnalyzer was used to measure erythrocyte arginine-tRNA synthetase activity in samples obtained from normal human twins of various ages. Variation in enzyme activity within the older DZ twins was five times that of the MZ twins suggesting the existence of genetically determined variation in enzyme activity. Higher enzyme activity was observed in newborn DZ unlike-sexed twins than in like-sexed twins for either zygosity. Possible explanations for this observation are discussed.

Adolescent↗