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H C Liu

Publications and source records attributed to H C Liu.

At least 37 records · Page 2Linked to original sources
PubMed2001

"Co-Flare" stimulation in the poor responder patient: predictive value of the flare response.

PURPOSE: In this study we review our experience with a day 2 start, "Co-Flare" protocol analyzing the flare response as a predictor of outcome in patients with a history of a poor response. METHODS: This study was conducted at a university based IVF Center. A total of 564 patient cycles over a 2.5-year time frame in patients that had either elevated FSH levels or a previous poor response to conventional leuprolide acetate down-regulated stimulation were retrospectively analyzed. These patients were treated with our co-flare protocol (1.0 mg of leuprolide acetate administered on day 2 and decreased on day 5 to 0.5 mg; gonadotropins initiated on day 3). We analyzed the initial flare response and the outcome for these patients. RESULTS: A total of 564 patients attempted to initiate an IVF cycle. The patients mean age was 39.4+/-3.7 years. Of the 450 cycles that started, the outcomes were as follows: 24% (108/450) cancellation, 20.4% (92/450) clinical pregnancy per initiated cycle, and a 14.0% delivery rate per initiated cycle. Patients with an estradiol flare that doubled were less likely to have cycles cancelled (13.6% vs. 35.6%, P < 0.01), but no differences were noted in pregnancy outcome if the cycle was not cancelled once the patient made it to retrieval. CONCLUSIONS: We have demonstrated an overall 14.0% delivery rate per initiated cycle in these "poor prognosis" patients. While the initial flare response (as indicated by a doubling of the estradiol by the second day of stimulation) was indicative of a better stimulation, no difference in pregnancy outcome was seen if the patient underwent retrieval.

Adult↗
PubMed2001

Early genes responsive to abscisic acid during heterophyllous induction in Marsilea quadrifolia.

The aquatic fern Marsilea quadrifolia produces different types of leaves in response to changes in natural environment and culture conditions. When the conditions are in favor of producing the submerged-type leaves, exogenous application of the plant hormone abscisic acid (ABA) induces the formation of aerial-type leaves. Tissues responsive to ABA were localized to the shoot apical meristem and the associated organ primordia. From these tissues, at least two tiers of ABA-regulated early genes were identified, including seven primary genes and seventeen secondary genes. These genes, designated ABRH for ABA-responsive heterophylly, showed diverse expression patterns during the course of heterophyllous induction. Changes in the transcript level of ABRH genes started early, within 0.5-1.0 h after the addition of ABA to the culture medium. Some changes were transient while the others were persistent. The ABRHs contain extensive sequence homology to known genes, including those encoding transcription factors, protein kinases, membrane transporters, metabolic enzymes, structural proteins and those encoded by the chloroplast genome. Identification of these ABRHs is a first step toward the understanding of the regulation mechanisms of heterophylly, and the results suggest the involvement of novel metabolic and regulatory pathways in ABA-controlled morphogenesis.

Abscisic Acid↗
PubMed2001

Autologous endometrial coculture in patients with in vitro-fertilization (IVF) failure: correlations of outcome with leukemia inhibiting factor (LIF) production.

PROBLEM: To determine if LIF produced by autologous endometrial co-culture (ECC) was associated with outcome in 46 patients with a history of multiple IVF failures. METHOD OF STUDY: The conditioned media (CM) from ECC cells exposed or non-exposed to human embryos was analyzed for LIF. RESULTS: Exposure or non-exposure to an embryo did not result in differing levels of LIF in the CM. LIF levels were significantly greater in the CM than in the serum controls (LIF was not found in the serum controls). Embryos grown on ECC demonstrated a significant improvement in number of blastomeres and fragmentation when compared to embryos grown in conventional media without ECC (6.7 +/- 1.3 vs. 5.6 +/- 1.2 blastomeres and 17.6% +/- 9.3 vs. 26.4% +/- 9.8 fragmentation; P < 0.05). When LIF levels were detectable in the CM, the embryos grown in ECC were of improved quality as compared to the embryos grown only in conventional media and demonstrated a non-significant increase in pregnancy rates (60 vs. 48%, P = 0.50). CONCLUSIONS: We have demonstrated a significant improvement in embryo quality with ECC. The cells in the ECC express LIF. The presence of LIF in the CM was associated with embryonic development and clinical pregnancy.

Adult↗
PubMed2001

A strategy to identify positional candidate genes conferring Marek's disease resistance by integrating DNA microarrays and genetic mapping.

Marker-assisted selection (MAS) to enhance genetic resistance to Marek's disease (MD), a herpesvirus-induced T cell cancer in chicken, is an attractive alternative to augment control with vaccines. Our earlier studies indicate that there are many quantitative trait loci (QTL) containing one or more genes that confer genetic resistance to MD. Unfortunately, it is difficult to sufficiently resolve these QTL to identify the causative gene and generate tightly linked markers. One possible solution is to identify positional candidate genes by virtue of gene expression differences between MD resistant and susceptible chicken using deoxyribonucleic acid (DNA) microarrays followed by genetic mapping of the differentially-expressed genes. In this preliminary study, we show that DNA microarrays containing approximately 1200 genes or expressed sequence tags (ESTs) are able to reproducibly detect differences in gene expression between the inbred ADOL lines 63 (MD resistant) and 72 (MD susceptible) of uninfected and Marek's disease virus (MDV)-infected peripheral blood lymphocytes. Microarray data were validated by quantitative polymerase chain reaction (PCR) and found to be consistent with previous literature on gene induction or immune response. Integration of the microarrays with genetic mapping data was achieved with a sample of 15 genes. Twelve of these genes had mapped human orthologues. Seven genes were located on the chicken linkage map as predicted by the human-chicken comparative map, while two other genes defined a new conserved syntenic group. More importantly, one of the genes with differential expression is known to confer genetic resistance to MD while another gene is a prime positional candidate for a QTL.

Animals↗
PubMed2001

Association analysis of the 5-HT6 receptor polymorphism C267T with depression in patients with Alzheimer's disease.

A significant increase of 267C allele of the 5-HT(6) receptor gene has been reported in patients with Alzheimer's disease (AD). Because a deficit in serotonergic neurotransmission is involved in major depression, we tried to find out whether 267C allele is associated with depressive disorders in AD. A psychiatrist interviewed all AD patients and their caregivers for evidence of depression using a Chinese version of the Standard Clinical Interview for DSM-III-R. The difference in the 5-HT(6) genotype or allele distributions between the AD patients with depressive disorders (n = 25) and those without (n = 120) was not significant.

Aged↗
PubMed2001

Characteristics of postictal psychosis in a psychiatric center.

The clinical characteristics of 12 cases of postictal psychosis treated at Taipei City Psychiatric Center, Taipei, Taiwan, were retrospectively reviewed. Increased seizure frequency, especially with generalized tonic-clonic seizures, was the major risk factor predisposing to postictal psychosis. The psychotic symptoms were variable with delusions and/or hallucinations. These patients showed a much longer history of epilepsy (21.9 +/- 10.7 years) prior to the development of postictal psychosis than has been previously reported. The possible mechanisms in the pathophysiology of psychosis in epileptics were discussed.

Adolescent↗
PubMed2001

Osteogenic evaluation of glutaraldehyde crosslinked gelatin composite with fetal rat calvarial culture model.

The cytotoxicity of the synthetic bone substitute composed of tricalcium phosphate and glutaraldehyde crosslinked gelatin (GTG) were evaluated by osteoblast cell culture. In a previous study, the GTG composites were soaked in distilled water for 1, 2, 4, 7, 14, 28, and 42 days, and then the solutions (or extracts) were cocultured with osteoblasts to evaluate the cytotoxicity of GTG composites by alive cell counting. In this study, the extracts were cocultured with the osteoblasts; thereafter, the concentration of transforming growth factor-beta (TGF-beta1) and prostaglandin E2 (PGE2) in the medium was analyzed to strictly reflect the biological effects of GTG composites on the growth of osteoblasts. In order to investigate the osteoconductive potential of the GTG composites on new bone formation in a relative short term, a model of neonatal rat calvarial organ culture was designed prior to animal experiments. Three experimental materials of 4, 8, and 12% GTG composites were evaluated by fetal rat calvarial organ culture for their ability for bone regeneration. Deproteinized bovine and porcine cancellous bone matrixes were used as the controlled materials. All the organ culture units were maintained in cultured medium for 5 weeks. Following the culture period, the morphology of tissue was observed under an optical microscope, and the quantitative evaluation of the new generation bone was determined by using a semiautomatic histomorphometeric method. Except in the initial 4 days, the concentration of TGF-beta1 of 4% and 8% GTG composites was higher than that of the blank group for all the other experimental time periods. The PGE2 concentration for 4% and 8% GTG composites was lower than that of the blank group. It revealed that the 4% and 8% GTG composites would not lead to inflammation and would promote osteoblast growth. The morphology and activity of the osteoblasts were not transformed or changed by the 2 GTG composites. For the 12% GTG composite, the performance of the in vitro condition was inferior to the blank group and the other 2 GTG composites. Although the concentration of TGF-beta1 and PGE2 was gradually back to normal after 14 days, the morphology of the osteoblasts was abnormal with features such as contracted cytoplast structures. The osteoblast was damaged perhaps in the initial stage. We suggested that the 4% and 8% GTG composites should be soaked in distilled water at least for 4 days before medical applications. The 12% GTG composite and the composites with a concentration of glutaraldehyde solution higher than 12% were not recommended as a medical prostheses in any condition. The fetal rat calvaria culture also showed the same results with the analysis of TGF-beta1 and PGE2. From the study, we could predict the results of animal experiments in the future.

Animals↗
PubMed2001

The synergistic effect of thrombopoietin in erythropoiesis with erythropoietin and/or IL-3 and myelopoiesis with G-CSF or IL-3 from umbilical cord blood cells of full-term neonates.

The authors sought to determine whether recombinant human thrombopoietin (TPO) acts synergistically with other cytokines on burst-forming unit-erythroid (BFU-E)-derived and colony-forming unit-granulocyte/macrophage (CFU-GM)-derived colony formations from cord blood. Cord blood nonadherent mononuclear cells (MNC) from normal full-term neonates were cultured in a methylcellulose system. When cultured with 5 x 10(4) MNC/mL, erythropoietin (EPO) 2 U/mL, interleukin-3 (IL-3) 50 ng/mL, and/or TPO 400 ng/mL (experiment 1), the addition of TPO to EPO gave rise to more BFU-E-derived colonies (p = .002). The addition of TPO to EPO + IL-3 gave rise to more BFU-E-derived colonies (p = .006) also. TPO synergizes erythropoiesis from cord blood. When cultured with IL-3 50 ng/mL, granulocyte colony-stimulating factor (G-CSF) 25 ng/mL, and/or TPO 400 ng/mL, the addition of TPO to IL-3 gave rise to more CFU-GM-derived colonies (p = .002). The addition of TPO to G-CSF gave rise to more CFU-GM-derived colonies (p = .002) also. TPO synergizes myelopoiesis from cord blood. Thus, TPO has synergistic effects on both erythropoiesis and myelopoiesis from cord blood. In the identical conditions of culture, cord blood had significantly greater BFU-E-derived or CFU-GM-derived colony formation than bone marrow (in a previous report by the authors) did. When cultured under conditions similar to those of experiment 1, but with 1 x 10(4) cord blood MNC/mL and TPO 100 ng/mL (experiment 2), results similar to those in the experiment 1 also revealed that TPO has synergistic effects on erythropoiesis and myelopoiesis from cord blood. In every individual assay, the numbers of BFU-E-derived or CFU-GM-derived colonies in experiment 1 were significantly higher than those in experiment 2.

Cell Count↗
PubMed2001

Genetic association analysis of alpha-1-antichymotrypsin polymorphism in Parkinson's disease.

alpha(1)-Antichymotrypsin (ACT) gene has been suggested as a susceptibility factor for Parkinson's disease (PD) and might be related to the onset of PD. We replicated these findings in a Chinese population. The results demonstrated that the ACT genotypic and allelic distributions showed no significant differences between the PD patient and the control groups. The age at onset was younger in the heterozygotes than in the homozygotes (p = 0.042). We suggest that the ACT polymorphism might play some role in the pathogenesis of PD, especially in the onset.

Age of Onset↗
PubMed2001

No association between tryptophan hydroxylase gene polymorphism and Alzheimer's disease.

Serotonergic dysfunction is implicated in Alzheimer's disease (AD) on the basis of studies of serotonin and its metabolite in postmortem specimens and CSF. There were also reports on association of a tryptophan hydroxylase (TPH) intron 7 variant and CSF 5-hydroxyindoleacetic acid concentrations. These suggested TPH might be a candidate to study for possible involvement in AD. Using a case-control association approach, we studied the TPH polymorphism in 150 subjects with AD and 100 controls. There were no significant differences in genotype or allele frequencies between controls and AD patients. The negative findings suggested that this TPH polymorphism has no major effect on the development of AD. However, the genetic variation of the TPH gene related to the symptomatology of AD deserves further investigation.

Aged↗
PubMed2001

Association study for a functional serotonin transporter gene polymorphism and late-onset Alzheimer's disease for Chinese patients.

Two recent studies have demonstrated an association for a deletion/insertion polymorphism within the promoter region of the serotonin transporter gene (5-HTTLPR), and Alzheimer's disease (AD). According to these studies, subjects with the short variant of the 5-HTTLPR gene are at increased risk for AD; however, this finding has not been confirmed by other workers. To evaluate the role of the 5-HTTLPR gene in susceptibility for AD, we conducted an association study for this polymorphism in a Chinese population. No significant differences were determined for genotype distribution or allele frequencies, comparing AD patients and normal controls. Even dividing the population into subgroups according to the presence of the APOE epsilon4 allele, no differences for genotype or allele frequencies were determined, comparing patients and controls. These results suggest that it is unlikely that the 5-HTTLPR polymorphism plays a substantial role in conferring susceptibility to AD.

Aged↗
PubMed2001

Phosphatidyl-inositol-3 kinase-independent insulin action pathway(s) in the human ovary.

Hyperandrogenism observed in women with a variety of insulin-resistant states is thought to be due to a stimulatory effect of insulin on ovarian steroid hormone production. However, it is not known what mechanisms could allow the ovary to remain sensitive to insulin while classical target organs for insulin action (liver, fat, and muscle) exhibit insulin resistance. One hypothesis proposed to explain this paradox suggests that a postbinding divergence of insulin receptor signaling occurs in the ovary and that signaling pathways for steroid hormone synthesis and other ovarian effects of insulin may be distinct from classical glucose signaling pathways. We now report that activation of phosphatidyl-inositol-3 (PI-3) kinase, which is crucial for glucose transport, is not necessary for the insulin-induced stimulation of progesterone production or for the insulin-induced inhibition of insulin-like growth factor binding protein 1 (IGFBP-1) production in cultured human ovarian cells. Human granulosa cells obtained during in vitro fertilization procedures were cultured with 10, 10(2), 10(3), or 10(4) ng/mL insulin with or without preincubation with 100 nM wortmannin, a specific irreversible inhibitor of PI-3 kinase. IGFBP-1 concentration in the conditioned medium was measured using immunoradiometric assay or by Western blot analysis. Progesterone concentration was measured using RIA. Additional studies were carried out in cultures of human ovarian cells prepared from homogenized whole ovarian tissue of a woman with a family history of breast cancer and a mutation of BRCA-1 gene who underwent bilateral oophorectomy. These cells were cultured with 10(3) ng/mL insulin with or without preincubation with 100 nM wortmannin. Two-way ANOVA was used to compare mean values of IGFBP-1 and progesterone according to insulin dose and the use of wortmannin. In cultured granulosa cell medium, progesterone production was stimulated by insulin in a dose-related manner up to 175% of control (P < 0.0001). In tissue culture medium from ovarian cells obtained from a patient with BRCA-gene mutation, concentration of progesterone in the tissue culture medium increased from 2.5 +/- 0.2 ng/mL for control to 5.4 +/- 0.3 ng/mL for cells incubated with insulin (P < 0.001). IGFBP-1 production in tissue culture medium from human granulosa cells was inhibited by insulin to the nadir of 45% of control (P < 0.0001). Preincubation with wortmannin, despite complete inhibition of PI-3 kinase in both cell systems confirmed by Western blot analysis, failed to significantly alter these results. We conclude that inhibition of PI-3 kinase by wortmannin fails to abolish stimulatory effect of insulin on progesterone production or inhibitory effect of insulin on IGFBP-1 production in cultured human ovarian cells. These findings suggest that activation of PI-3 kinase, an enzyme crucial for insulin-stimulated glucose transport, is not necessary for the above effects of insulin in the ovary. These data provide evidence for the presence of PI-3 kinase-independent insulin signaling pathway(s) in human ovarian cells.

Androstadienes↗
PubMed2001

Genomic analysis of the Hsp70 superfamily in Arabidopsis thaliana.

The Arabidopsis genome contains at least 18 genes encoding members of the 70-kilodalton heat shock protein (Hsp70) family, 14 in the DnaK subfamily and 4 in the Hsp110/SSE subfamily. While the Hsp70s are highly conserved, a phylogenetic analysis including all members of this family in Arabidopsis and in yeast indicates the homology of Hsp70s in the subgroups, such as those predicted to localize in the same subcellular compartment and those similar to the mammalian Hsp110 and Grp170. Gene structure and genome organization suggest duplication in the origin of some genes. The Arabidopsis hsp70s exhibit distinct expression profiles; representative genes of the subgroups are expressed at relatively high levels during specific developmental stages and under thermal stress.

Arabidopsis↗
PubMed2001

Cytotoxic and antioxidant effects of the water extract of the traditional Chinese herb gusuibu (Drynaria fortunei) on rat osteoblasts.

BACKGROUND AND PURPOSE: Gusuibu (Drynaria fortunei) is a traditional Chinese herb that has been claimed to have therapeutic effects on bone healing; however, a clinical mechanism responsible for this effect has not been identified. This study evaluated the cytotoxic and antioxidant effects of the water extract of gusuibu (WEGSB) on rat osteoblasts. MATERIALS AND METHODS: Osteoblasts were prepared from neonatal Wistar rat calvarias and treated with WEGSB. Cell viability and alkaline phosphatase activity were determined. Intracellular reactive oxygen species were detected using the dye 2',7'-dichlorofluorescin, and mitochondrial membrane potential was detected using the dye 3,3'-dihexyloxacarbocyanine iodide and flow cytometry. RESULTS: WEGSB at 1 and 10 micrograms/mL was not cytotoxic to rat osteoblasts, but WEGSB at 100 micrograms/mL reduced cell viability and alkaline phosphatase activity in a time-dependent manner. Although WEGSB and hydrogen peroxide did not affect the mitochondrial membrane potential of rat osteoblasts, combined treatment with WEGSB (100 micrograms/mL) and hydrogen peroxide lowered the membrane potential of mitochondria and resulted in cell death. The basal level of intracellular reactive oxygen species in rat osteoblasts was significantly suppressed by WEGSB at 10 to 100 micrograms/mL. WEGSB (10 micrograms/mL) specifically inhibited hydrogen peroxide-induced oxidative stress without an effect on nitric oxide-induced stress. Hydrogen peroxide caused concentration-dependent death of rat osteoblasts, but WEGSB significantly protected cells from hydrogen peroxide-induced death. CONCLUSION: This study has shown that WEGSB at 10 micrograms/mL is not cytotoxic to rat osteoblasts in vitro, and also that the extract at 10 micrograms/microL has an antioxidant effect on these cells. The antioxidant activity of WEGSB can protect rat osteoblasts from hydrogen peroxide-induced death and may promote bone recovery under similar pathologic conditions.

Alkaline Phosphatase↗
PubMed2001

Pharmacokinetics of enantiomers of trans-tramadol and its active metabolite, trans-O-demethyltramadol, in human subjects.

AIM: To study the stereoselectivity in pharmacokinetics of the enantiomers of trans-tramadol (trans-T) and its active metabolite, trans-O-demethyltramadol (M1) in human subjects. METHODS: Trans-T hydrochloride sustained-release tablets were taken orally by 12 healthy male volunteers. After a multiple dosage schedule, the serum concentrations of (+)-trans-T, (-)-trans-T, (+)-M1, and (-)-M1 were determined in serum by high performance capillary electrophoresis (HPCE). RESULTS: (+)-Trans-T, (-)-trans-T, (+)-M1 and (-)-M1 in human serum were separated by HPCE. The linear range was 2.5-320 microg/L for the enantiomers of trans-T, and 2.5-50 microg/L for the enantiomers of M1. For the enantiomers of trans-T and M1, the intra-day and inter-day RSD were less than 15 % and 20 %, and the relative recoveries were 94.3 %-106.2 % and 90.4 %-107.8 %, respectively; the limit of quantitation was 1.25 microg/L. The serum concentrations of the enantiomers of trans-T reached a steady state in 12 subjects on d 4 after the initial administration. The steady state serum concentrations of (+)-trans-T were higher than that of (-)-trans-T at every sampling points in the subjects. The differences were significant in the main pharmacokinetic parameters between (+)-trans-T and (-)-trans-T except Tmax. The serum concentrations of (-)-M1 were higher than that of (+)-M1 in most subjects and at most sampling time points. There were significant differences in Cmax and Cmin between the enantiomers of M1. CONCLUSION: The pharmacokinetics of trans-T and M1 was found to be stereoselective. (+)-Trans-T was shown to be absorbed completely, but eliminated more slowly. The pharmacokinetic stereoselectivity of M1 was different among human subjects.

Adolescent↗
PubMed2001

Distribution of enantiomers of trans-tramadol and trans-O-demethyltramadol in central nervous system of rats.

AIM: To investigate the distribution of the enantiomers of trans-tramadol (trans-T) and its active metabolite, trans-O-demethyltramadol (M1), in the central nervous system (CNS). METHODS: After a single ip dose of trans-T hydrochloride or M1, the rats were killed by decapitation. A high performance capillary electrophoresis (HPCE) method was used to determine the concentrations of enantiomers of trans-T and M1 in the serum and different brain tissues, including cerebrospinal fluid (CF), cerebral cortex (CC), corpus striatum (CS), hypothalamus (HY), cerebellum (CE), and medulla oblongata (MO). RESULTS: After ip trans-T hydrochloride, the concentrations of (+)-trans-T were higher than those of (-)-trans-T in the serum and all tested brain tissues; The concentrations of (+)-M1 were lower than those of (-)-M1 in the all tested brain tissues; The concentrations of the enantiomers of trans-T and M1 were the highest in the CC, the lowest in the CF. After ip M1, the concentrations of (+)-M1 were higher than those of (-)-M1 in the serum and all tested brain tissues; The concentrations of the enantiomers of M1 were the highest in the CC, the lowest in the CF. CONCLUSION: The concentrations of the enantiomers of trans-T and M1 varied in the serum and different brain tissues. The distribution of trans-T and M1 in the CNS of rats was stereoselective. The stereoselectivity in the distribution of M1 after M1 injection was different with that after trans-T injection.

Animals↗
PubMed2001

Positive association of ankylosing spondylitis with homozygous HLA-B2704, but protection with B2705 in Taiwan Chinese.

The study was undertaken to determine the effects of HLA-B27 subtypes on susceptibility to ankylosing spondylitis (AS) in Taiwan Chinese, a polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) method was developed for subtyping of HLA-B27. In this series, there are 62 patients with AS who were tested HLA-B27 positive serologically and 738 normal persons over the age of 65. Among the 738 normal controls, 42 (5.7%) were HLA-B27 positive. There were six (14.3%) homozygous for B2704, 18 (42.9%) heterozygous for B2704, 2 (4.8%) double heterozygous for B2704 and B2705, one (2.3%) double heterozygous for B2704 and B2706, 2 (4.8%) homozygous for B2705, 11 (26.1%) heterozygous for B2705, and 2 (4.8%) heterozygous for B2706. In our patients with AS, 37 (59.7%) were homozygous for B2704 and 25 (40.3%) were heterozygous for B2704. The HLA-B27 carrier rate in Taiwan healthy old persons is estimated at 5.7%. Susceptibility to AS is determined by homozygosity for B2704. However, B2705 may be an indicator of protection against AS in Taiwan Chinese.

Aged↗