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Chia-Li Yu

Publications and source records attributed to Chia-Li Yu.

27 records · Page 2Linked to original sources
PubMed2003

Rapid detection of beta-globin gene (HBB) mutations coupling heteroduplex and primer-extension analysis by DHPLC.

Beta-thalassemia is a common inherited disease, resulting from one or more of a total of more than 200 different mutations in the beta-globin gene (HBB). Efficient and reliable mutation-screening methods are essential in order to establish appropriate prevention programs for at-risk populations based upon a molecular diagnosis. We have developed a rapid and highly-specific mutation screening test for the diagnosis of beta-thalassemia by coupling heteroduplex and primer-extension analysis based on the denaturing high performance liquid chromatography (DHPLC) system. A total of 161 healthy heterozygous Taiwanese carriers featuring 10 different HBB mutations and 30 patients exhibiting 12 different compound heterozygous or homozygous HBB mutations were subjected to DHPLC. The elution profile for the heteroduplex analysis of DHPLC could be successfully used to identify the common disease-causing mutations of HBB. To further confirm the sequence variants, we developed a technique combining multiplex primer-extension analysis coupled with DHPLC for the genotyping of eight common disease-causing mutations in the HBB gene. Overall, by coupling heteroduplex and primer-extension analysis based upon DHPLC, we were able to unambiguously identify the most-common beta-thalassemia mutations corresponding to more than 99% of HBB alleles among the Taiwanese population. In conclusion, compared to classic approaches to mutation screening for this malady, we suggest that DHPLC is an excellent technique to be applied to the genetic screening of prenatal and postnatal individuals as a part of a diagnosis program for beta-thalassemia and provides a more-efficient, economic, and sensitive means to undertake such a screening program.

Base Sequence↗
PubMed2003

Low concentrations of arsenic induce vascular endothelial growth factor and nitric oxide release and stimulate angiogenesis in vitro.

Arsenic (As) is widely distributed in nature, and its contamination in drinking water remains a major public health problem. Exposure to As may lead to degenerative peripheral vascular diseases. The purpose of this study is to clarify the role of As in modulating cell proliferation and in vitro angiogenesis in human umbilical vein endothelial cells (HUVECs) and to scrutinize the contributing factors of these events. The results revealed that lower concentrations (up to 1 microM) of sodium arsenite stimulated HUVEC cell growth. An in vitro angiogenesis assay indicated that low concentrations of As increased vascular tubular formation, which was abrogated by hemoglobin, a potent nitric oxide scavenger. In contrast, higher concentrations of As (>5 micro M) revealed cytotoxicity and inhibition to angiogenesis. We also demonstrated that lower concentrations of As upregulated the expression of constitutive nitric oxide synthase (NOS3) at both transcriptional and translational levels and that lower concentrations of As implicated a modulatory role in vascular endothelial growth factor (VEGF) expression. In addition, low concentrations of As (<1 micro M) increased von Willebrand Factor (vWF) antigen expression, whose elevation paralleled the onset of angiogenesis and was considered an early indicator of endothelial activation in tumor metastasis. VEGF and basic fibroblast growth factor can synergistically upregulate the vWF gene expression. Therefore, we conclude that the treatment of HUVECs with As leads to cell proliferation and activation, which preferentially enhances angiogenesis in vitro, possibly via the VEGF-NOS signaling pathway. The molecular mechanism(s) by which As facilitates angiogenesis remains to be elucidated.

Arsenites↗
PubMed2003

Helium-neon laser irradiation stimulates migration and proliferation in melanocytes and induces repigmentation in segmental-type vitiligo.

Low-energy helium-neon lasers (632.8 nm) have been employed in a variety of clinical treatments including vitiligo management. Light-mediated reaction to low-energy laser irradiation is referred to as biostimulation rather than a thermal effect. This study sought to determine the theoretical basis and clinical evidence for the effectiveness of helium-neon lasers in treating vitiligo. Cultured keratinocytes and fibroblasts were irradiated with 0.5-1.5 J per cm2 helium-neon laser radiation. The effects of the helium-neon laser on melanocyte growth and proliferation were investigated. The results of this in vitro study revealed a significant increase in basic fibroblast growth factor release from both keratinocytes and fibroblasts and a significant increase in nerve growth factor release from keratinocytes. Medium from helium-neon laser irradiated keratinocytes stimulated [3H]thymidine uptake and proliferation of cultured melanocytes. Furthermore, melanocyte migration was enhanced either directly by helium-neon laser irradiation or indirectly by the medium derived from helium-neon laser treated keratinocytes. Thirty patients with segmental-type vitiligo on the head and/or neck were enrolled in this study. Helium-neon laser light was administered locally at 3.0 J per cm2 with point stimulation once or twice weekly. The percentage of repigmented area was used for clinical evaluation of effectiveness. After an average of 16 treatment sessions, initial repigmentation was noticed. Marked repigmentation (>50%) was observed in 60% of patients with successive treatments. Basic fibroblast growth factor is a putative melanocyte growth factor, whereas nerve growth factor is a paracrine factor for melanocyte survival in the skin. Both nerve growth factor and basic fibroblast growth factor stimulate melanocyte migration. It is reasonable to propose that helium-neon laser irradiation clearly stimulates melanocyte migration and proliferation and mitogen release for melanocyte growth and may also rescue damaged melanocytes, therefore providing a microenvironment for inducing repigmentation in vitiligo.

Adolescent↗
PubMed2002

The stimulatory effects of nasal discharge from patients with perennial allergic rhinitis on normal human neutrophils are normalized after treatment with a new mixed formula of Chinese herbs.

In our previous study, we found a new mixed formula of Chinese herbs containing Shin-yi-san + Xiao-qing-long-tang + Xiang-sha-liu-jun-zi-tang (9 + 3 + 3 g divided in three doses/day) was beneficial to the patients with perennial allergic rhinitis (AR) via complicated immunomodulatory effects on both mononuclear cells (MNC) and polymorphonuclear neutrophils (PMN). In the present study, we further determined the effects of nasal fluid from AR patients on the functions of human PMN before and after treatment with the mixed formula. We found the nasal discharge, but not serum, from AR group with high serum IgE (H-IgE, serum IgE >200 KIU/l) before treatment exerted many stimulating effects on normal PMN including delayed apoptosis, enhanced production of soluble intercellular adhesion molecule 1 (sICAM-1), interleukin 8 (IL-8) and prostaglandin E2 (PGE2), increased phagocytosis, and augmented cyclooxygenase 2 (COX-2) mRNA expression of PMN. However, these stimulating effects of nasal fluid on PMN were not found in low IgE group (L-IgE, serum IgE <200 KIU/l). These PMN-enhancing effects of H-IgE nasal fluid were abolished after 3-month treatment with the mixed Chinese herb formula. In conclusion, our results suggest that the new mixed herb formula treatment suppressed nasal mucosa inflammation by normalizing stimulatory effects of allergic nasal discharge of patients with H-IgE allergic rhinitis.

Adolescent↗
PubMed2002

Arsenic induces tumor necrosis factor alpha release and tumor necrosis factor receptor 1 signaling in T helper cell apoptosis.

Long-term exposure to arsenic induces arsenical cancers in human beings. Arsenic has been shown to induce apoptosis in a variety of cell systems. Previous studies revealed that patients with arsenic-induced Bowen's disease showed a defective cell-mediated immunity and decreased percentages of T cell and T helper cell subpopulations in peripheral mononuclear cells. The purpose of this study was to investigate the effects of arsenic on T cell survival and function in mononuclear cells. Arsenic concentrations higher than 1 micro M induced tumor necrosis factor alpha release from mononuclear cells and caused a cytotoxic effect on T cells. When exposed to higher concentrations of arsenic, apoptosis was induced. CD4+ cells were the major apoptoic population in mononuclear cells. Tumor necrosis factor receptor 1 expression on CD4+ cells, but not Fas/FasL, was significantly enhanced by arsenic treatment compared to other mononuclear cells. Increased expressions of tumor necrosis factor receptor 1 related death domain proteins and activated caspases were observed. These findings indicate that tumor necrosis factor receptor 1 signaling is the major pathway in arsenic-induced T helper cell apoptosis.

Adult↗
PubMed2002

Effect and correlation of serum total IgE, eosinophil granule cationic proteins and sensitized allergens in atopic dermatitis patients with or without rhinitis.

To understand the relevance of serological parameters and eliciting allergens in the patients with atopic dermatitis (AD) and patients with atopic dermatitis in combination with rhinitis (ADR), we compared the serum total IgE, major basic protein (MBP) and eosinophil cationic protein (ECP) levels and identified the sensitized allergens in these two groups. The serum levels of total IgE, MBP and ECP were not significantly different in these two groups. Patients with ADR had a higher positive rate of aeroallergens including housedust, mite (D.F), mite (D.P) and cockroach than patients with AD. However, a high positive rate of seafood allergens (include crab, shellfish and shrimp) was observed in patients with AD. The serum IgE level correlated well with serum MBP level (r = 0.603, P = 0. 019) in patients with ADR. There was a strong correlation between serum MBP and ECP level (r = 0.773, P = 0.005) in patients with AD and in patients with ADR (r = 0.721, P = 0.008). We also found that numbers of sensitized allergens correlated well with total IgE in patients with AD (r = 0.760, P = 0.001) and in patients with ADR (r = 0.487, P = 0.004). These results suggested that the aeroallergens are the most important allergens causing and aggravating atopic diseases in Taiwan. Seafood may play an important role in the pathogenesis of AD. We suggest the measurement of serum total IgE combined with Multiple Allergens Simultaneous Test-Chemiluminescent Assays(AST-CLA) test could be helpful in the diagnosis of atopic diseases.

Adolescent↗
PubMedDate not supplied

Decreased IL-12 production by polymorphonuclear leukocytes in patients with active systemic lupus erythematosus.

Polymorphonuclear leukocytes (PMN) play an important role in eradicating bacterial infections. To test if PMN of patients with systemic lupus erythematosus (SLE) have defective capacity to produce IL-12, IL-12 p35 gene transcription and p70 excretion by PMN were evaluated in SLE patients and normal subjects. Peripheral blood PMN from 25 patients with active SLE and 25 normal individuals were stimulated with lipopolysaccharide (LPS, 100ng/mL) in the presence or absence of recombinant interferon (IFN)-gamma (5-200IU/mL). The IL-12 p35 gene transcripts were analyzed by reverse transcription - polymerase chain reaction (RT-PCR) and the IL-12 p70 in culture supenatants was quantified by enzyme immunoassay (EIA). At the 6th hour of stimulation, IL-12 expression in PMN of SLE patients was less prominent than that of the normal controls. The IL-12 was produced by normal PMN on LPS stimulation in the absence of IFN-gamma. IFN-gamma enhanced the IL-12 production by normal PMN stimulated with LPS, but it inhibited the IL-12 production in PMN from active lupus patients in the presence of LPS. Analysis with PCR using the same primers on the chromosomal DNA showed that p35 gene was intact in SLE patients. These results have suggested that SLE-PMN may have defect in IL-12 expression and the defect may be exaggerated in the presence of IFN-gamma which normally stimulates IL-12 production. This may account for increased susceptibility to multiple infections in patients with active SLE.

Adolescent↗
PubMedDate not supplied

Antenatal treatment of chylothorax and cystic hygroma with OK-432 in nonimmune hydrops fetalis.

OBJECTIVES: To present our experience of using OK-432 in treating fetal cystic hygroma and chylothorax complicated with nonimmune hydrops fetalis. METHODS: OK-432 (Picibanil) was injected into the fetal pleural cavity or fetal cystic hygroma. RESULTS: Patient 1: A 23-year-old, gravida 2, para 1, was found to have a recurrent fetal chylothorax at GA 29 weeks. Serial amnioreduction and thoracocentesis was performed at GA 31, 32, 33, and 34 weeks. Intrapleural OK-432 injection was performed twice at GA 33 and 34 weeks. Cyanosis and respiratory distress were noted immediately after birth (GA 34 weeks). The baby expired despite of aggressive neonatal resuscitation. Patient 2: A 26-year-old, gravida 2, para 1, was found to have a cystic hygroma of her fetus at GA 17 weeks. Karyotype of the cystic fluid and the amniocytes were 46, XY. Fetal ascites developed at GA 22 weeks. OK-432 injection into the tumour was performed at GA 23 weeks. Stabilization of the cystic hygroma was noted throughout the pregnancy (about 3.5 cm in diameter). Serial fetal paracentesis and/or amnioreduction were performed. Karyotype of the ascites was again 46, XY. Maternal dietary modification with medium chain triglyceride was also prescribed. Chylothorax developed and the baby was born by cesareans at GA 32 weeks. Resolution of pleural effusion, ascites, and regression of cystic hygroma were noted since the 2nd day after birth. The baby had survived beyond 4 months of age at submission. CONCLUSION: Combination of antenatal OK-432 injection, maternal dietary modification, serial thoracocentesis plus paracentesis, together with amnioreduction and tocolysis, appeared to contribute to the success of antenatal treatment. Fetal pulmonary expansion may determine the immediate neonatal survival.

Adult↗