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Biomedical subjects

L I Lin

Publications and source records attributed to L I Lin.

At least 19 recordsLinked to original sources
PubMed2000

Total deviation index for measuring individual agreement with applications in laboratory performance and bioequivalence.

In areas of inter-laboratory quality control, method comparisons, assay validation and individual bioequivalence, etc., the agreement between observations and target (reference) values is of interest. The mean of the squared difference between observations and target values (MSD) is a good measure of the total deviation. A new user-friendly statistic, the total deviation index (TDI(1-p)), is introduced that translates the MSD into an index that can be directly compared to a predetermined criterion. The TDI(1-p) describes a boundary such that a majority, 100(1-p) per cent, of the observations are within the boundary (measurement unit and/or per cent) from their target values. Statistical inference using the sample counter part (estimate) is presented. A Monte Carlo experiment with 5000 runs was performed to confirm the estimate's validity. Applications in laboratory performance and validation, as well as individual bioequivalence, are presented.

Analysis of Variance↗
PubMed2000

Parvovirus B19 infection associated with the production of anti-neutrophil cytoplasmic antibody (ANCA) and anticardiolipin antibody (aCL).

We described four patients who had clinical diagnosis of erythema infectiosum and presented with skin rash, polyarthralgia, polyarthritis, and mild fever. Anti-parvovirus B19 IgM and IgG antibodies were found in all four patients and parvovirus B19 DNA was detected in three of the four patients by polymerase chain reaction (PCR) in sera using standard methods. Anticardiolipin antibody (aCL) was positive in three of the four patients included three with anti-beta2 glycoprotein I (beta2GPI). The immunoglobulin isotype of aCL was found to be IgM. Anti-neutrophil cytoplasmic antibody (ANCA) included three p-ANCA and one c-ANCA was detected in all four patients by indirect immunofluoresence (IIF). Both anti-proteinase 3 (PR3) and anti-myeloperoxidase (MPO) antibodies were found in two patients whom had polyarthritis for more than 6 months. These data indicate parvovirus B19 may be linked to the induction of an autoimmune response.

Adult↗
PubMed1999

The spectrum of microsatellite loci on chromosomes 7 and 8 in Taiwan aboriginal populations: a comparative population genetic study.

Sixteen microsatellite loci on chromosomes 7 and 8 of Han-Taiwanese and six Taiwan aboriginal populations were systematically analyzed by a high-resolution multiple-fluorescence-based polymerase chain reaction technique. Analysis of allele frequency distribution indicated the genetic divergence among these populations. Several alleles were unique to specific tribes. Only the D8S556 locus deviated from Hardy-Weinberg equilibrium in all tribes. Its F(IS) level, as calculated with the Nei method, was also higher and more homozygous than expected. Therefore, with the exception of D8S556, these variable number of tandem repeats (VNTR) loci are suitable genetic markers for forensic and paternal testing. The F(ST) level, as the proportion of the total variation among these tribes, ranged from 1.4% at the D7S484 locus to 6.8% at the D7S550 locus. The average F(ST) was 3.9%, suggesting that there were substantial variations among these populations. The genetic identity analysis and the genetic distance analysis reached the same conclusions, viz., that the Ami and the Paiwan tribes were genetically close to each other, that the Atayal tribe was relatively unique compared with other tribes, and that the Saisiat tribe was relatively close to the Han-Taiwanese. A dendrogram for these tribes was further constructed by the UPGMA method. These VNTR data not only facilitate forensic and paternity testing, but also provide anthropometric information for further elucidating the relationship of Taiwan populations to the Austronesian family.

Asian People↗
PubMed1997

Stability of curcumin in buffer solutions and characterization of its degradation products.

The degradation kinetics of curcumin under various pH conditions and the stability of curcumin in physiological matrices were investigated. When curcumin was incubated in 0.1 M phosphate buffer and serum-free medium, pH 7.2 at 37 degrees C, about 90% decomposed within 30 min. A series of pH conditions ranging from 3 to 10 were tested and the result showed that decomposition was pH-dependent and occurred faster at neutral-basic conditions. It is more stable in cell culture medium containing 10% fetal calf serum and in human blood; less than 20% of curcumin decomposed within 1 h, and after incubation for 8 h, about 50% of curcumin is still remained. Trans-6-(4'-hydroxy-3'-methoxyphenyl)-2,4-dioxo-5-hexenal was predicted as major degradation product and vanillin, ferulic acid, feruloyl methane were identified as minor degradation products. The amount of vanillin increased with incubation time.

Antioxidants↗
PubMed1997

PIG-A gene mutations in four Taiwanese patients with paroxysmal nocturnal haemoglobinuria following aplastic anaemia.

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired haemolytic disorder caused by deficient biosynthesis of the glycosyl phosphatidylinositol (GPI) anchor in haemopoietic stem cells. PIG-A, an X-linked gene that participates in the first step of GPI-anchor synthesis, is responsible for PNH. Various abnormalities of the PIG-A gene have been demonstrated in all patients with PNH so far examined. In this study we characterized the somatic mutations in PIG-A gene in four Taiwanese patients with PNH. We identified five novel mutations in the PIG-A gene, three single nucleotide substitution mutations (-342, C-->G, codon 335, GGT-->AGT and codon 405, GCT-->GTT) and two frameshift mutations (codon 22, GGA-->G-A and codon 356, TGT-->TGTT) in the PIG-A gene. The -342 mutation was judged to be a polymorphism. Furthermore, three patients had previous clinicopathologic evidence which suggested aplastic anaemia (AA), before the development of PNH. One of these was found to have thrombocytopenia during follow-up. We suggest that the somatic PIG-A gene mutations highlight a subgroup of AA having a pathogenetic link with PNH.

Anemia, Aplastic↗
PubMed1994

Allelotype and loss of heterozygosity of p53 in primary and recurrent hepatocellular carcinomas. A study of 150 patients.

BACKGROUND: The allelotype and loss of heterozygosity (LOH) of the p53 gene in human hepatocellular carcinoma (HCC) were studied in 150 patients with resected primary HCC and 18 with recurrent HCC. METHODS: DNA samples of paired HCC and livers were cut with BanII enzyme for the study of p53 allelotype and allele loss. The medical records of the patients were carefully reviewed. RESULTS: Sixty-four (42.7%) patients were heterozygous for the p53 gene, 69 (46%) were homozygous for the 1.5/1.4 kb small (S) allele, and 17 (11.3%) were homozygous for the 2.9 kb large (L) allele. The frequencies of the minor L allele (0.323) and of the major S allele (0.677) in this population of Chinese patients differed from the frequencies previously reported for North American Caucasians (0.13 and 0.87, respectively). The heterozygous patients tended to have lower serum hepatitis B surface- and e antigens (HBsAg and HBeAg) and higher diabetes mellitus (DM) than did homozygous patients (SS and LL). Thirty-seven (57.8%) of the 64 heterozygous patients had a tumor-specific p53 allele LOH, being two times more common in HCC tumors larger than 8 cm than in HCC tumors 2 cm or smaller. The frequency of DM was four times higher in the heterozygous patients who had p53 LOH than in those who retained both alleles. LOH of p53 did not correlate with tumor invasiveness or differentiation, hepatitis B or C virus infection, or prognosis. CONCLUSION: The allelotype of p53 gene in HCC correlates with HBsAg and HBeAg seropositivities and DM. LOH of the p53 gene is a common event in HCC, correlates with DM, and occurs less often in familial HCC. LOH can identify the clonal origin of recurrent HCC but is not a critical prognostic factor.

Adult↗
PubMed1994

The amplification refractory mutation system (ARMS): a rapid and direct prenatal diagnostic technique for beta-thalassaemia in Singapore.

beta-Thalassaemia major patients have chronic anaemia and since 3-4 per cent of Singaporeans carry the beta-gene, prenatal diagnosis is essential. We evaluated the amplification refractory mutation system (ARMS) technique as a routine test for prenatal diagnosis of beta-major. Six mutations along the beta-gene were studied--41-42 (-TCTT), IVSII #654 (C-T), 17 beta (A-T), -28 TATA (A-G), IVSI #5 (G-C), and IVSI #1 (G-T). Our results indicate that prenatal diagnosis using these mutations can be offered to 90 per cent (35/39) of our Chinese couples and 54.6 per cent (12/22) of our Malay couples at risk. Confirmation of ARMS results was carried out using allele-specific oligonucleotide hybridization. Prenatal diagnosis using ARMS was successfully carried out in nine cases which included a set of triplets and twins. The triplets were diagnosed with the beta-trait carrying the 41-42 mutation. The couple with twins possessed the #654 mutation and one twin was diagnosed with the beta-trait and the other with #654 homozygosity. Genomic sequencing of the undefined mutations in the Chinese couples revealed rarer mutations at -29 and an ATG-AGG base substitution at the initiation codon for translation. In the Malay couples, genomic sequencing detected mutations at codon 15 (TGG-TAG) and codon 26 (GAG-AAG). We conclude that ARMS with its direct detection of amplified products by gel electrophoresis provides an accurate, rapid, and simpler method for our beta-thalassaemia prenatal diagnosis programme in Singapore.

Autoradiography↗
PubMed1992

Analysis of hemoglobin gamma chain in patients with Cooley's anemia in Taiwan.

The beta-like globin gene cluster, consisting of five genes and a pseudogene, is located on chromosome 11 and is arranged in the order 5'-epsilon-G gamma-A gamma-phi beta-delta-beta-3'. With the fast and sensitive method of high-performance liquid chromatography (HPLC) in the gradient mobile system, we studied the G gamma values of fetal hemoglobin in 34 patients with Cooley's anemia, 100 normal adults and 100 newborns. There were 84 newborns with a mean G gamma value of 67.41 +/- 2.37%, 15 newborns with a G gamma value of 83.45 +/- 1.92% and one newborn with a G gamma value of 100%. Because the medium value of 67.41% and 100% is near the value of 83.45%, we speculate that there are different g gene genotypes; that is, the group with a G gamma value of 100% has a genotype of G gamma-G gamma/G gamma-G gamma, the group with a G gamma value of 83.45% has a genotype of G gamma-G gamma/G gamma-A gamma, and the group with a G gamma value of 67.41% has a genotype of G gamma-A gamma/G gamma-A gamma. The G gamma value for normal adults was 41.84 +/- 20.91%. While the G gamma values for patients with Cooley's anemia were divided into two groups, 56.23 +/- 6.55% and 80.60 +/- 3.05%. There was no case having a G gamma value of 100%. Our results suggest that the expression of the gamma gene in Cooley's anemia is similar to that of the newborns.

Adult↗
PubMed1992

Detection of enterovirus RNA in patients with idiopathic dilated cardiomyopathy by polymerase chain reaction.

The pathogenic role of enterovirus in patients with idiopathic dilated cardiomyopathy has been determined through a molecular biologic approach. Sensitivity in the detection of viral genomes in tissues varied between conventional nucleic acid hybridization and polymerase chain gene amplification. To improve diagnosis, we developed a strategy for reverse transcription polymerase chain reaction (RT-PCR) to detect viral RNA. We synthesized two sequence-specific oligonucleotides, primer 1 (5'dACCGACGAATACCACTGTTA3') and primer 2 (5'dCCTCCGGCCCCTGAATGCGGCTAAT3'), complementary to the 5' conserved viral genomic fragments. Viral RNA was amplified by double PCR with these two primers and hybridized with a 32-P labeled inter-primer probe (5'dATGAAACCCACAGGCACAAAG3'). Using this strategy, we detected as little as 10(-8) micrograms of coxsackievirus B3 RNA after amplification with RT-PCR, but detected none in the plasma of eight healthy adults. Among 15 patients with idiopathic dilated cardiomyopathy, viral RNA could be detected in one out of 12 plasmas (8%) and three out of four explanted heart tissues (75%). In contrast, no viral RNA could be detected in six samples of myocardial tissue from patients with other heart diseases. The only patient who had viral RNA in his plasma also had viral RNA in his myocardium. Thus, the high incidence of viral RNA in these patients suggests a possible etiologic link between them. Correct selection of specific PCR primers and the application of double PCR can improve chances of diagnosing enteroviral infection.

Adolescent↗
PubMed1992

A new codon 31 (-C) mutant resulting in beta zero-thalassemia.

A new beta zero-thalassemia mutation, a frameshift mutation with deletion of a single cytosine nucleotide in codon 31, is described. The propositus, which is compound heterozygous for this mutation and the 17 beta A-T beta zero-thalassemia mutation, has the phenotype of severe beta-thalassemia major.

Base Sequence↗
PubMed1991

The spectrum of beta-thalassemia mutations in Taiwan: identification of a novel frameshift mutation.

Seventy-four beta-thalassemia genes from 37 unrelated beta-thalassemia-major patients were systematically characterized by using PCR, dot-blot hybridization, and direct sequencing of amplified genomic DNA. We found that six mutations--namely, II-654, 41/42, -28, 17 beta, -29, and 27/28--were prevalent, accounting, respectively, for 45.9%, 28.4%, 10.8%, 10.8%, 1.4%, and 2.7% of studied patients. The 27/28 mutation has at codon 27-28 a cytosine insertion which has never been reported before. These results indicate that four oligo-probes (II-654, 41/42, -28, and 17 beta) allow allele-mutant determination by oligonucleotide analysis in 95.9% of this group of patients, and direct sequencing can be carried out for other samples. These data will facilitate the prenatal diagnosis of this disease by DNA analysis in Taiwan.

Alleles↗
PubMed1990

Cell type-specific protein-DNA interactions in the human zeta-globin upstream promoter region: displacement of Sp1 by the erythroid cell-specific factor NF-E1.

The protein-DNA interactions of the upstream promoter region of the human embryonic zeta-globin gene in nuclear extracts of erythroid K562 cells and nonerythroid HeLa cells were analyzed by DNase I footprinting, gel mobility shift assay, methylation interference, and oligonucleotide competition experiments. There are mainly two clusters of nuclear factor-binding sites in the zeta promoter. The proximal cluster spans the DNA sequence from -110 to -60 and consists of binding sites for CP2, Sp1, and NF-E1. NF-E1 binding is K562 specific, whereas CP2 binding is common to both types of cells. Overlapping the NF-E1- and CP2-binding sites is a hidden Sp1-binding site or CAC box, as demonstrated by binding studies of affinity-purified Sp1. In the distal promoter region at -250 to -220, another NF-E1-binding site overlaps a CAC box or Sp1-binding site. Extract-mixing experiments demonstrated that the higher affinity of NF-E1 binding excluded the binding of Sp1 in the K562 extract. NF-E1 factors could also displace prebound Sp1 molecules. Between the two clusters of multiple-factor-binding sites are sequences recognized by other factors, including zeta-globin factors 1 and 2, that are present in both HeLa and K562 extracts. We discuss the cell type-specific, competitive binding of multiple nuclear factors in terms of functional implications in transcriptional regulation of the zeta-globin gene.

Base Sequence↗
PubMed1989

Competitive effects of long-chain-triglyceride emulsion on the metabolism of medium-chain-triglyceride emulsions.

This study was conducted to assess the potential metabolic competitive interactions of intravenous medium-chain-triglyceride (MCT) and long-chain-triglyceride (LCT) lipid emulsions. To assess this competition increasing concentrations of LCT emulsion were added to an intravenous dose of MCT emulsion of 3.0 g/kg body wt up to a maximum dose of 3.0 g LCTs/kg body wt. Blood samples were assessed for competitive interactions by analyzing the following metabolites: glucose, insulin, lactate, pyruvate, ketones (acetoacetate, beta-hydroxybutyrate), elimination of triglycerides, and free fatty acids. Evaluation of the data showed a strong competitive interaction between the MCT and LCT emulsions. This competition was evident as soon as LCTs were added to the MCT infusions and appeared to favor LCTs for removal and metabolism over MCTs. This appears to indicate that there is a peripheral, strong affinity site for LCT removal and metabolism and a shared peripheral site and specific visceral site for MCT removal and metabolism.

Animals↗
PubMed1989

A concordance correlation coefficient to evaluate reproducibility.

A new reproducibility index is developed and studied. This index is the correlation between the two readings that fall on the 45 degree line through the origin. It is simple to use and possesses desirable properties. The statistical properties of this estimate can be satisfactorily evaluated using an inverse hyperbolic tangent transformation. A Monte Carlo experiment with 5,000 runs was performed to confirm the estimate's validity. An application using actual data is given.

Analysis of Variance↗
PubMed1987

The use of multivariate analysis to compare peroxisome induction data on phthalate esters in rats.

This paper contains statistical evaluations of the effect of 9 different plasticizers on rat hepatic peroxisome proliferation. There were 9 21-day feeding studies with one plasticizer in each study. The plasticizers are: di(2-ethylhexyl)phthalate (DEHP), butyl benzyl phthalate (BBP), 711 phthalate (711P), di(n-butyl)phthalate (DBP), di(undecyl)phthalate (DUP), di(isodecyl)phthalate (DIDP), di(isononyl)phthalate (DINP), 610 phthalate (610P), and di(ethylhexyl)adipate (DEHA). For each plasticizer, several dosage (as % of diet) groups, plus a negative control group (0%) and a reference control group (1.2% DEHP) were included. There were 5 males and 5 females, approximately 5 weeks old, per group per plasticizer, for a total of 470 animals. For each animal, body weight and food intake were measured prior to treatment and twice a week during the treatment period. Animals were necropsied at the end of the 21-day treatment period. Selected organs and blood samples of each animal were collected for measuring hepatic enzymes, proteins, fat stains, organ weights and serum fats. The endpoints included electron microscopy examination of liver peroxisome proliferation and liver histological abnormalities. The statistical evaluation utilized a multivariate approach that condensed a complex phenomenon into certain meaningful and simple endpoints for quantitative comparisons. The dose of each plasticizer that would protect 99% and 99.9% of rats against peroxisome proliferation (xx% statistically predicted dose, or xx% SPD) was estimated. Marked differences were seen in the ability of the 9 test compounds to cause hepatic peroxisome proliferation in rats. The graphic ranking of overall potency is, in order from most potent to least potent: DEHP, DIDP, DINP, DBP, DEHA, DUP, BBP, 711P and 610P. The ranking in terms of 99.9% SPD is: DEHP, DINP, DIDP, DBP, 610P, DUP, DBP, 711P and DEHA. It was also found that the histological findings of reduced basophilia or increased eosinophilia were highly correlated with peroxisome proliferation (r = 0.94). The other histological findings were incidental observations for specific plasticizers.

Analysis of Variance↗