PubMed Health⌕ Search

Biomedical subjects

B Fang

Publications and source records attributed to B Fang.

8 recordsLinked to original sources
PubMed1992

Distribution of ADH2 and ALDH2 genotypes in different populations.

The distribution of the human liver alcohol dehydrogenase, ADH2, and aldehyde dehydrogenase, ALDH2, genotypes in 21 different populations comprising Mongoloids, Caucasoids, and Negroids was determined by hybridization of the amplified genomic DNA with allele-specific oligonucleotide probes. Whereas the frequency of the ADH1(2) allele was found to be relatively high in the Caucasoids, Mexican Mestizos, Brazilian Indios, Swedish Lapps, Papua New Guineans and Negroids, the frequency of the ADH2(2) gene was considerably higher in the Mongoloids and Australian Aborigines. The atypical ALDH2 gene (ALDH2(2)) was found to be extremely rare in Caucasoids, Negroids, Papua New Guineans, Australian Aborigines and Aurocanians (South Chile). In contrast, this mutant gene was found to be widely prevalent among the Mongoloids. Individuals possessing the abnormal ALDH2 gene show alcohol-related sensitivity responses (e.g. facial flushing), have the tendency not to be habitual drinkers, and apparently suffer less from alcoholism and alcohol-related liver disease.

Alcohol Dehydrogenase↗
PubMed1992

Estimation for model parameters of batch fermentation kinetics.

Based on the widely accepted mathematical model of fermentation kinetics, an analytical solution is deduced in this paper. To describe the feature of batch fermentation, the parameters of the fermentation kinetics in the analytical solution (i.e., mumax, Ks, beta, YG, YP, and m) are estimated at one strike with POWELL optimization algorithm coded in FORTRAN-77. The experimental data in the example is quoted from a batch lysine fermentation process using Corynebacterium glutamicum. The result shows that: 1) the calculated values of the mathematical model agree very well with the experimental data; 2) the synthesis rate of lysine depends on both the growth rate and the concentration of the biomass.

Algorithms↗
PubMed1992

Detection of point mutations of the phenylalanine hydroxylase gene and prenatal diagnosis of phenylketonuria.

The known mutant alleles of the human phenylalanine hydroxylase (PAN) gene were analyzed in 25 phenylketonuria (PKU) families from North China by using polymerase chain reaction and allele-specific oligonucleotide dot blot hybridization techniques. The results showed that the six mutations analyzed accounted for 62% of all PKU genes. The three most frequent mutations were R243Q, R413P and Y204C. Seven prenatal gene diagnoses were carried out in 6 PKU families and were confirmed after birth or by examination of aborted materials.

Base Sequence↗
PubMed1992

[Analysis of RFLP haplotypes and point mutations at the phenylalanine hydroxylase (PAH) locus in PKU families from north China].

A study of DNA polymorphisms at the phenylalanine hydroxylase (PAH) locus was performed using 28 classical phenylketonuria (PKU) families from North China. In the families analyzed, haplotype 4 accounted for 77% of normal chromosomes and 79% of PKU gene bearing chromosomes. Two new haplotypes, haplotypes 49 and 50, were found. On the basis of haplotype analysis, only 37%-40% of PKU carriers in North China were heterozygous and therefore informative for linkage studies. Exon 3 (Arg111----stop) and exon 6 (Tyr204----Cys204) mutations of the PAH gene were studied using the polymerase chain reaction (PCR) and allele specific oligonucleotide probe hybridization in 42 PKU families from North China. These accounted for 3.6% and 9.5% of PKU mutations in North China, respectively.

Base Sequence↗
PubMed1992

[Polymorphisms of the D13S26 locus in Chinese and its application to linkage analysis of Wilson disease].

The D13S26 locus has been mapped to 13q21.1-q21.2 and is linked with Wilson disease gene at a distance of 3.8 centimorgans. The polymorphic alleles detected by HphI, EcoRI and BclI at the D13S26 locus are the same in Chinese as in Caucasians, but the allele frequencies are quite different. As calculated from 30 unrelated Chinese individuals, the allele frequencies were as follows: HphI 2.8 kb(0.47)/2.0kb(0.53); EcoRI 9.0 kb (0.02)/8.0 kb (0.98); BclI 6.3 kb (0.02)/5.6 kb (0.98). Cosegregation analysis of the D13S26 locus and Wilson disease locus was carried out in 3 families with the disease. In one of these families, the proband and his younger sister (7-years-old and phenotypically normal) were both heterozygous for this site. We predict with 85.6% confidence that the younger sister is in the presymptomatic stage of Wilson disease.

Alleles↗
PubMed1991

Serotoninergic varicosities make synaptic contacts with pleural sensory neurons of Aplysia.

Serotonin is a modulatory neurotransmitter that produces many of the cellular changes associated with sensitization of reflexes in Aplysia. These changes have been carefully documented in sensory neurons located in the abdominal ganglion that mediate the gill-siphon withdrawal reflex and in sensory neurons located in the pleural ganglion that mediate the tail-siphon withdrawal reflex. Although serotonin appears to be necessary for sensitization, there is no direct evidence that serotoninergic neurons make synaptic contacts with sensory neurons. In this study, the immunoperoxidase technique was used to label serotonin-immunoreactive neurites surrounding the cell bodies of sensory neurons in the pleural ganglion. Serotonin-immunoreactive neurites had varicosities whose mean short axis diameter was 1.1 +/- 0.6 microns (mean +/- S.D.). The shape of the size distribution was skewed toward larger sizes, however, suggesting that there were multiple subpopulations of varicosities. One subpopulation was that of varicosities located at branch points whose average short axis diameter was larger than normal (1.7 +/- 0.5 microns). Serotonin-immunoreactive varicosities were directly apposed to the sensory neurons without intervening glial cells. In most contacts, serotonin-immunoreactive neurites invaginated into the plasma membranes of the sensory neurons. There were also a few contacts onto spinelike processes, but these were flat rather than invaginated. Serotoninergic neurons whose activity produces changes in the electrophysiological properties of sensory neurons have been identified, but this study provides the first direct evidence for synaptic connections between serotoninergic neurons and sensory neurons in Aplysia.

Animals↗
PubMed1991

The application of simplex method to the estimation of kinetic and energetic parameters of microbial growth.

Based on the mathematical models derived by the author for describing both batch and continuous microbial cultivation, the application of simplex method to the estimation of mu max, Ks, Ymaxx/s and ms is studied. The paper also presents the methods of determining objective function and initial value of simplex method and of introducing the whole process of estimation with single tank continuous culture of E. coli as an example.

Escherichia coli↗