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Biomedical subjects

C Y Lai

Publications and source records attributed to C Y Lai.

At least 19 recordsLinked to original sources
PubMed2006

A double-blind randomized controlled trial of oral misoprostol and intramuscular syntometrine in the management of the third stage of labor.

BACKGROUND: The aim of this study was to compare the efficacy and safety of oral misoprostol 400 mug with intramuscular syntometrine in the management of the third stage of labor. MATERIAL AND METHODS: This was a double-blind randomized controlled trial conducted in a tertiary care hospital. Three hundred and fifty-five women randomized to receive either oral misoprostol 400 mug or intramuscular syntometrine in the third stage of labor were studied. The change in hemoglobin level from before to 48 h after delivery, use of additional oxytocics and treatment related side effects were the main outcome measures. RESULTS: There were no significant differences between the two groups in terms of the change in hemoglobin level and mean blood loss. The incidence of shivering was significantly higher in the misoprostol group whilst that of vomiting was significantly higher in the syntometrine group. There were no differences in the incidence of nausea, headache, diarrhea and pyrexia between the two groups. CONCLUSION: Orally administered misoprostol at a dose of 400 mug is an acceptable alternative in preventing post-partum blood loss, as measured by the peri-partum change in hemoglobin level and was not associated with an increased incidence of side effects.

Administration, Oral↗
PubMed2005

A study of PSORS1C1 gene polymorphisms in Chinese patients with psoriasis.

BACKGROUND: Although genetic analyses have identified the HLA-Cw*0602 allele as the major risk allele for chronic plaque psoriasis in various ethnic groups, it has been proposed that the association of Cw*0602 is due to linkage disequilibrium and that other nearby genes are involved in susceptibility to psoriasis. The psoriasis susceptibility 1 candidate 1 (PSORS1C1, formerly SEEK1) gene, located 127 kb telomeric to the HLA-C locus, is considered to be one of the potential candidate genes of psoriasis. Up to the present, no association study of the PSORS1C1 gene has been conducted on Chinese patients with psoriasis. OBJECTIVES: We aimed to determine whether the genetic polymorphisms of the PSORS1C1 gene were associated with an increased risk of psoriasis in Chinese patients. METHODS: We investigated the PSORS1C1 gene for disease association by direct sequencing of the PSORS1C1 gene in 143 Chinese patients with chronic plaque psoriasis and 188 control subjects. Genotyping for HLA-Cw*0602 and the alpha-helix coiled-coil rod homologue (C6orf18, formerly HCR) gene was also carried out using a sequence-based typing method. RESULTS: We identified 10 single nucleotide polymorphisms (SNPs) on the PSORS1C1 gene in our subjects; four of these SNPs cause amino acid change. We also detected poly(C) repeat variants from nucleotide positions 386-392 (poly(C)6-8). The poly(C) repeat polymorphisms cause a frame shift mutation. Another poly(C) repeat variant was also found at nucleotide positions 748-751. No significantly different allelic distributions of the PSORS1C1 SNPs or poly(C) repeat polymorphisms could be found between the patients with chronic plaque psoriasis and controls after correction for multiple testing. However, a significant increase of the Cw*0602 allele and tryptophan-tryptophan allele of the C6orf18 gene (HCR*WW) was found in patients with early onset psoriasis (21.9% vs. 4.8%, P < 10(-7)). Haplotype-based association analysis also showed a susceptibility haplotype carrying Cw*0602 and HCR*WW alleles in early onset Chinese patients. CONCLUSIONS: Our results indicate that the PSORS1C1 gene might not play an important role in the causation of chronic plaque psoriasis in Chinese people.

Adolescent↗
PubMed2001

Assessment of donor fatty livers for liver transplantation.

AIM: The effect of fatty liver on graft survival, especially with reference to macrovesicular and microvesicular steatosis, is still uncertain. This preliminarily study was designed to create a noninvasive method for the quantification of the hepatic fat content in vivo and to establish provisional criteria for the assessment of fatty donor livers before liver transplantation among transplant surgeons, radiologists, and pathologists. METHODS AND MATERIALS: Different degrees of rat fatty liver model were established by feeding rats a diet deficient in choline and methionine for different periods of time. Computed tomography (CT) with test tubes containing variable percentages of fat equivalent substance were used to assess the severity of fatty change of the rat liver. This was then correlated with the histological classification, level of hepatic enzymes, and graft survival. RESULTS: Linear correlation between the fat volume fraction added to the test tubes and CT density were found. The process of producing a fatty liver via diet alteration peaked at week 3. At this time hepatic enzymes, radiological fat content, and posttransplantation survival were worse (P=0.013), compared with other time points. Radiological assessment of fatty liver correlated well with survival and serum glutamic oxaloacetic transaminase and glutamic pyruvate transaminase levels. CONCLUSION: Severe microvesicular steatosis does not influence recipient survival, however, macrovesicular steatosis affects graft survival. Caliber CT is a practical and simple method that allows an accurate noninvasive quantitative assessment of hepatic fatty infiltration. It has potential to be a useful parameter for the assessment of donor livers for clinical liver transplantation.

Animals↗
PubMed2001

Identification of two down-regulated genes in rat liver allografts by mRNA differential display.

Total RNA differential display (DD) using random primers was performed for rat orthotopic liver transplantation (OLT) models. DA (RT1a) donor livers were transplanted into DA, PVG (RT1c), and LEW (RT1l) recipients: (1) syngeneic OLT (DA-DA): no rejection occurs; (2) allogeneic OLT (DA-PVG): rejection occurs, but is naturally overcome without immunosuppression; (3) allogeneic OLT (DA-LEW): animals die of acute rejection within 14 days. cDNA was isolated from selected bands, re-amplified for sequencing, and confirmed by Northern blots. Two down-regulated genes were observed in day-7 allogeneic OLT livers (DA-PVG, DA-LEW), while they were consistently expressed in day-7 syngeneic OLT (DA-DA) livers. These two genes were identified as alpha-glutathione sulfotransferase (alpha-GST) Ya gene and estrogen sulfotransferase (EST), respectively. Northern blots confirmed that their expression was down-regulated in OLT (DA-PVG) livers on days 7-26 and gradually restored. The mRNA expression of GST and EST may be good markers to predict rejection or induction of tolerance.

Animals↗
PubMed2001

The development of phonological awareness: effects of spoken language experience and orthography.

Phonological awareness, the ability to analyze spoken language into small sound units, has been shown to be affected by the individual's early orthographic experience (alphabetic vs. non-alphabetic). Past studies, however, have not differentiated the effect of script alphabeticity from that of spoken language experience, which covaries strongly with the phonological properties of the language. The present study compares younger, pre-reading to older, literate children from different linguistic backgrounds on their phonological awareness. Hong Kong and Guangzhou subjects both spoke Cantonese. The latter subjects had early experience with Pinyin (alphabetic) in addition to their logographic Chinese reading; the former read only logographic Chinese. New Zealand subjects spoke English and read the Roman alphabet. Results showed that: (1) the Hong Kong and Guangzhou pre-readers performed very similarly at all levels of phonological awareness; (2) the New Zealand pre-readers outperformed their Hong Kong and Guangzhou counterparts on onset, rime, and coda analyses; (3) the Guangzhou reading children outperformed their Hong Kong counterparts on onset and coda analyses. Whereas finding (3) reflects an effect of alphabeticity in the first learned script, finding (2) in combination with finding (1) indicates an effect of early spoken language experience independent of orthography. The fact that orthographic and spoken language experience both impact on the development of phonological skills implies a mediating function of phonological awareness in integrating sound information derived from reading and perceiving speech.

Age Factors↗
PubMed2001

Polymorphism of human HLA-DRB1 antigens generated by genetic exchange between DR2 (DRB1*15011) and DR6 (DRB1*1405) alleles: a novel DRB1 allele (DRB1*1437) identified in a Paiwan tribe member of Taiwan.

We report herein the identification of a new DRB1 allele using sequence-based typing (SBT). This novel allele, HLA-DRB1*1437, was found in an aboriginal individual from the Paiwan tribe in the southern part of Taiwan. This individual was typed by SBT method as having an HLA genotype of HLA-A*02011/0203, HLA-B*15011/3901, HLA-DRB1*11011/1437, HLA-DRB3*0202/0202, and HLA-DPB1*0501/1301. This new allele differs from DRB1*1309 in the 5'-end nucleotide sequence of polymorphic exon 2 at codon 16 (CAT-->CAA; H16Q), codon 37 (AAC-->TTC; R37F), codon 47 (TTC-->TAC; F47Y), and codon 58 (GCC-->GCT; both specify alanine). By sequence comparison, it was found that this new allele has a 5'-end sequence (from amino acid residues 7 to 66) identical to that found in the DRB1*1405 allele and a 3'-end sequence (from amino acid residues 58 to 94) identical to that found in the DRB1*15011 allele. Both DRB1*1405 and DRB1*15011 alleles have been identified among the Paiwan members (Note).

Alleles↗
PubMed2001

New DR5 sequences: a novel DRB1*11122 allele identified in Paiwan tribe members of Taiwan and a corrected sequence for the DRB1*1201 allele.

We report herein the identification of a new DRB1 allele using sequence-based typing (SBT). This novel allele, HLA-DRB1*11122, was found in an aboriginal individual (SWP71) from the Paiwan tribe in the southern part of Taiwan. This individual was typed by SBT method as having an HLA genotype of HLA-A*24021/24021, HLA-B*4001/4002, HLA-DRB1*11122/15011, HLA-DRB3*0202, and HLA-DRB5*01011. This new allele differs from DRB1*1112 in the polymorphic exon 2 only at codon 34 (CAA-->CAG; both specify glutamine) and from DRB1*1110 in the exon 2 sequence only at codon 32 (CAT-->TAT; H32T). The most likely candidate allele which is found in the aboriginal populations of Taiwan and which may mutate into this new allele is DRB1*11011. DRB1*11122 allele differs from DRB1*11011 allele in the polymorphic exon 2 at both codon 34 (CAA-->CAG) and codon 37 (TAC-->TTC; T37F). This novel HLA-DRB1*11122 allele was also found in another aboriginal individual (SWP90) from the same Paiwan tribe. This SWP90 individual was typed by SBT method as having an HLA genotype of HLA-A*24021/24021, HLA-B*4002/5502, HLA-DRB1*11122/1201, and HLA-DRB3*01011/0202. However, the original DRB1*1201 sequence from HERLUFF was found to be erroneously reported and the corrected sequence from SWP90 is now presented herein.

Alleles↗
PubMed2001

Video-assisted thoracoscopic T2 sympathetic block by clipping for palmar hyperhidrosis: analysis of 52 cases.

BACKGROUND: Endoscopic thoracic sympathectomy or sympathicotomy is a standard method in treating palmar hyperhidrosis, but postoperative compensatory sweating may be troublesome in some patients. Therefore, we designed a new technique for only T2 sympathetic blocking by clipping instead of interruption of the sympathetic trunk. PATIENTS AND METHODS: Between September 2000 and July 2001, we saw a total of 100 patients with palmar hyperhidrosis who underwent video-assisted thoracoscopic sympathetic blocking of the T2 ganglion. All patients were placed in a semisitting position under single-lumen intubated anesthesia. We performed sympathetic blocking by clipping of the T2 ganglion at the level of the second and third rib beds using an 8-mm, 0 degree thoracoscope (Storz). RESULTS: We supposed that the postoperative improvement in palmar hyperhidrosis would be perfect. The operation could be accomplished within 30 minutes. All patients were discharged within 4 hours after the operation. Surgical complications were minimal, without surgical mortality. A few patients were willing to receive the reverse operation and should get improvement of compensatory sweating after removal of the endo clips. CONCLUSION: We believe that video-assisted thoracoscopic T2 sympathetic block by clipping will be a safe and effective method of treating patients with palmar hyperhidrosis. Compensatory sweating may be improved by the reverse operation: removal of the endo clip.

Adolescent↗
PubMed2000

Telomerase activity in rat liver allografts.

BACKGROUND: Telomerase activity in grafts may be involved in the alteration of cellular senescence after transplantation or its relevant immunological events. METHODS: At the age of 20 weeks, donor livers harvested from DA (RT1a) were orthotopically transplanted into PVG (RT1c) or LEW (RT1(1)) rats. Rats having undergone orthotopic liver transplantation (OLT; DA-PVG) naturally overcome rejection, whereas all OLT (DA-LEW) rats die from acute rejection within 14 days. Telomerase activity in liver allografts was measured at various intervals post OLT. RESULTS: At day 7 when the most severe rejection episode was observed in OLT (DA-LEW) and OLT (DA-PVG), the telomerase activity was significantly higher than in syngeneic OLT (DA-DA) rats, in which no rejection occurred. Telomerase activity in tolerogenic OLT (DA-PVG) livers remained elevated for at least 2 months. CONCLUSION: These results suggest that telomerase activity in allogeneic OLT livers may reflect regenerating hepatocytes or activation of lymphocytes and/or hematopoietic stem cells associated with rejection or tolerance.

Animals↗
PubMed2000

Clusterin may be involved in rat liver allograft tolerance.

Little is known about the possible role of complement inhibitors on tolerance induced by liver allografts. Clusterin, which is a plasma glycoprotein, inhibits cytolytic membrane attack complex (MAC) of complement by binding to soluble C5b-7 complex. The role of clusterin in relation to the naturally achieved tolerance in a rat orthotopic liver transplantation (OLT) has not been investigated before. Here we determined the kinetics of clusterin expression at different post-transplantation time points in a tolerogenic model (DA-PVG) where rejection was naturally overcome without any immunosuppressive drugs in comparison with the syngenic OLT model (DA-DA). Peripheral blood and liver tissues were taken from OLT at various post-operative time points. A strong expression of soluble clusterin was observed on post-transplantation day 7, which occurred at the peak of the rejection in this tolerogenic OLT model. The expression of clusterin remained strong even after tolerance was achieved. The intensity of clusterin expression was much stronger when compared with the syngenic OLT (DA-DA) model after OLT. A strong expression of clusterin mRNA was also observed in the tolerogenic model on post-OLT day (POD) 7 and the expression persisted when compared with the syngenic model on post-OLT day 60. Our data have shown that the strongest levels of clusterin during the reaction phase in tolerogenic OLT may be involved in tolerance induction.

Animals↗
PubMed2000

Identification of the indoleamine 2,3-dioxygenase nucleotide sequence in a rat liver transplant model.

A tryptophan catabolizer, indoleamine 2,3-dioxygenase (IDO) is highly expressed in the placenta and plays an essential role in maternal tolerance. Recent data have shown that the administration of an IDO inhibitor blocked not only maternal tolerance but also liver allograft tolerance. However, little is known about the induction of IDO in liver allografts, although a gene specific for tryptophan 2,3-dioxygenase (TDO) is believed to be expressed in the liver. In the present study, we investigated whether IDO is induced in liver allografts. Synthetic oligonucleotide primers based on the mouse IDO cDNA sequence were used to amplify RNA derived from livers of donor, syngeneic or allogeneic OLT rats. RNA encoding IDO was induced in the rat allogeneic liver after orthotopic liver transplantation (OLT), but not in syngeneic OLT. The rat nucleotide sequence of the RT-PCR products obtained from OLT livers revealed identities of 89% homology to the mouse IDO and of 68% to the human IDO. This study demonstrated the presence of RNA encoding IDO in allogeneic OLT livers, which may be involved in the immune response after liver transplantation.

Amino Acid Sequence↗
PubMed2000

Performance characteristics of PM10 samplers under calm air conditions.

The size range of airborne particles that is closely related to specific deposition regions in the human respiratory tract and excess lung burden of these deposited particles is associated with disease. Size-selective sampling, therefore, needs to be performed to assess the related health risks. Performance criteria applied to these samplers must be well characterized in order to provide accurate and reliable results. The PM10 samplers that have been used in place of the total suspended particulate samplers for the collection of ambient air particles are more relevant to potential inhalation hazards. In order to be certified, a PM10 sampler must meet reliable performance specifications, primarily the aerosol penetration test with liquid and solid particles in a wind tunnel (wind speeds of 2, 8, and 24 km/hr). This testing is intended to assure reasonable accuracy in aerosol measurements. However, the sampler performance under calm air conditions has not been well studied. In the present study, the sampling heads of three devices--the Harvard impactor, the Personal Environmental Monitor (PEM), and the Sierra Andersen model 241 dichotomous sampler PM10 inlet head--were tested for aerosol separation efficiency. With the consideration of bias and imprecision of the measurements, five specimens of each type of sampler were chosen for performance testing, repeating the tests 5 times for each specimen. An ultrasonic atomizing nozzle was used to nebulize potassium sodium tartrate tetrahydrate and dioctyl phthalate particles as the solid and liquid challenge aerosols, respectively. The aerosol number concentrations and size distributions upstream and downstream of the samplers were measured by using an aerosizer calibrated against a settling velocity chamber. The results showed that among the samplers tested, the dichotomous sampler PM10 inlet head had the best fit to the PM10 convention, while the other two samplers not only appeared to have a steeper separation-curve slope but also had significant particle bounce when challenged with solid particles. Analysis of variance also confirmed the superiority of the dichotomous samplers. Surface-coating with oil or grease greatly reduced the problem of particle bounce.

Aerosols↗
PubMed1999

Purification, characterization, and molecular cloning of an outer layer protein of carp fertilization envelope.

An outer layer protein of carp fertilization envelope (FE), FEO-1, was purified from carp oocytes. The cDNAs encoding FEO-1 were cloned. The mature protein of FEO-1 is 21 kDa in molecular weight and contains 177 amino acid residues whose sequence has 58% identity to the outer layer protein of chick vitelline membrane. In situ hybridization and immunocytochemistry show that FEO-1 is expressed in oocytes and liver. In oocytes, FEO-1 is stored in the cortical granules. During cortical reaction, it is exocytosed to the perivitelline space and then gradually added to the outer layer of FE (FE(o)). FEO-1 first appears as discrete deposits along FE(o), then merges to form a continuous layer. The thickness of FE(o) increases as cortical reaction proceeds. In addition to FEO-1, FE(o) contains cystatin, fibroin-like substance (FLS), and cathepsin-like substance (CLS) as well. They are stored in the cortical granules and are exocytosed to FE(o) simultaneously with FEO-1 during cortical reaction. In FE(o), FEO-1 is present in monomer form and can be completely extracted by sodium dodecyl sulfate (SDS)-mercaptoethanol (MSH). On the other hand, the cystatin, FLS, and CLS present in FE(o)are cross-linked together. They are partially extracted by SDS-MSH but can be completely extracted by guanidium thiocyanate-lauroylsarcosine.

Amino Acid Sequence↗
PubMed1999

Molecular recognition by acetylcholinesterase at the peripheral anionic site: structure-activity relationships for inhibitions by aryl carbamates.

Substituted phenyl-N-butyl carbamates (1-9) are potent irreversible inhibitors of Electrophorus electricus acetylcholinesterase. Carbamates 1-9 act as the peripheral anionic site-directed irreversible inhibitors of acetylcholinesterase by the stop-time assay in the presence of a competitive inhibitor, edrophonium. Linear relationships between the logarithms of the dissociation constant of the enzyme inhibitor adduct (Ki), the inactivation constant of the enzyme-inhibitor adduct (k2), and the bimolecular inhibition constant (k(i)) for the inhibition of Electrophorus electricus acetylcholinesterase by carbamates 1-9 and the Hammett substituent constant (sigma), are observed, and the reaction constants (ps) are -1.36, 0.35 and -1.01, respectively. Therefore, the above reaction may form a positive charged enzyme-inhibitor intermediate at the peripheral anionic site of the enzyme and may follow the irreversible inactivation by a conformational change of the enzyme.

Acetylcholinesterase↗