Biomedical subjects

H W Liu

Publications and source records attributed to H W Liu.

At least 37 records · Page 2Linked to original sources

PubMed2001

Familial Mediterranean fever in a Taiwanese patient.

Familial Mediterranean fever is a rare disease characterized by cyclic attacks of fever, serositis and strong family background. Here we report a 22-year-old man who suffered from recurrent fever accompanied by chest and abdominal pain for more than 10 years. The attack frequency was about once per 2-3 weeks. Although he consulted many clinics and even received appendectomy at the age of 15, no definite diagnosis was given. During the admission, many laboratory examinations failed to show any abnormality except mild leukocytosis and elevated C-reaction protein. Image studies including chest X ray and abdominal CT scan showed negative result but, interestingly, Gallium-67 scan showed a hot spot in right lower chest and right lower abdomen. After prophylaxis with colchicine 1.0 mg per day, he has enjoyed more than 2 years without the above symptoms.

Adult↗

PubMed2001

Tumor necrosis factor promoter polymorphisms in patients with rheumatoid arthritis in Taiwan.

OBJECTIVE: To investigate the association of tumor necrosis factor (TNF) promoter polymorphisms with rheumatoid arthritis (RA) in Taiwan. METHODS: TNF promoter polymorphisms at positions -238, -244, -308, -376, -857, and -863 were determined in 97 patients with RA and 97 healthy controls using the PCR-RFLP method. RESULTS: The phenotypic frequency of TNF-308A was significantly lower in patients with RA than in healthy controls. This finding can only be found in HLA-DR4 negative patients, not in DR4 positive RA patients and controls. The TNF promoter polymorphisms at positions -238, -244, -308, -376, -857, and -863 were not related to the clinical manifestations of RA patients. CONCLUSION: TNF-308A itself or a neighboring gene may be a protective factor for the development of RA in the HLA-DR4 negative population in Taiwan. TNF promoter polymorphisms were not associated with the clinical manifestations of patients with RA in Taiwan.

Arthritis, Rheumatoid↗

PubMed2001

Arginase levels are increased in patients with rheumatoid arthritis.

Arginase and nitric oxide synthase (NOS) compete for the same substrate, L-arginine. The reciprocal regulation of arginase and NOS in L-arginine-metabolizing pathways has recently been demonstrated. Since NOS is involved in the inflammation of human arthritides, we hypothesized that this reciprocal regulation might also occur within the inflamed synovium. The present study shows that both serum arginase activity and protein levels were significantly higher in patients with rheumatoid arthritis (RA) than in patients with systemic lupus erythematosus (SLE) or osteoarthritis (OA) or in healthy controls. Arginase protein concentrations in supernatants of monocyte cultures from RA patients were also significantly higher than in those from SLE or OA patients or healthy controls. In RA patients, there was a significant correlation between the serum concentrations of arginase protein and rheumatoid factor (r = 0.82, p < 0.0001). These data indicate that increased arginase production is seen in RA patients, but not in other immune-related diseases, suggesting that increased arginase production is unique to, and may play an important role in, the pathogenesis of RA disease.

Arginase↗

PubMed2001

Systemic lupus erythematosus complicated by recurrent spontaneous pneumothorax--a case report.

Despite frequent pleuro-pulmonary involvement, spontaneous pneumothorax is rare in patients with systemic lupus erythematosus (SLE). Here, we report a 17-year-old female patient with SLE, complicated by multiple organs involvement. She initially presented with interstitial pneumonitis and pulmonary hemorrhage, followed by spontaneous pneumothorax and CNS involvement. The patient was treated with immunosuppressive agents, including steroid and cyclophosphamide pulse therapies. Spontaneous pneumothorax happened to her once again at a different location during treatment. After aggressive therapy, the disease activity of SLE gradually diminished, and pneumothorax had not recurred during the further follow-up. Therefore, the pneumothorax may occur in SLE patients with high disease activity.

Adolescent↗

PubMed2001

[Determination of 4-aminobutyric acid in pumpkin powder by high performance liquid chromatography].

A method for the separation and determination of the 4-aminobutyric acid in pumpkin powder by high performance liquid chromatography (HPLC) with post-column derivatization and fluorescence detection is described. The operating conditions were cation exchange resin column (30 cm x 0.4 cm i.d.) with gradient elution of buffer solutions A [19.6 g sodium citrate dihydrate and 1.0 g phenol dissolved in 1 L water, pH(3.15 +/- 0.02)] and B [21.0 g sodium nitrate and 1.5 g boric acid dissolved in 1 L water, pH(9.70 +/- 0.02)] as mobile phase at a flow rate of 0.5 mL/min, and a column temperature of 62 degrees C, with detection wavelength lambda ex = 338 nm, lambda em = 425 nm. The retention time of 4-aminobutyric acid was 34.77 minutes. The average recovery was 99% and the coefficient of variation was 1.35%. This method is simple, rapid and sensitive.

Cation Exchange Resins↗

PubMed2000

Physiological control of smooth muscle-specific gene expression through regulated nuclear translocation of serum response factor.

Prolonged serum deprivation induces a structurally and functionally contractile phenotype in about 1/6 of cultured airway myocytes, which exhibit morphological elongation and accumulate abundant contractile apparatus-associated proteins. We tested the hypothesis that transcriptional activation of genes encoding these proteins accounts for their accumulation during this phenotypic transition by measuring the transcriptional activities of the murine SM22 and human smooth muscle myosin heavy chain promoters during transient transfection in subconfluent, serum fed or 7 day serum-deprived cultured canine tracheal smooth muscle cells. Contrary to our expectation, SM22 and smooth muscle myosin heavy chain promoter activities (but not viral murine sarcoma virus-long terminal repeat promoter activity) were decreased in long term serum-deprived myocytes by at least 8-fold. Because serum response factor (SRF) is a required transcriptional activator of these and other smooth muscle-specific promoters, we evaluated the expression and function of SRF in subconfluent and long term serum-deprived cells. Whole cell SRF mRNA and protein were maintained at high levels in serum-deprived myocytes, but SRF transcription-promoting activity, nuclear SRF binding to consensus CArG sequences, and nuclear SRF protein were reduced. Furthermore, immunocytochemistry revealed extranuclear redistribution of SRF in serum-deprived myocytes; nuclear localization of SRF was restored after serum refeeding. These results uncover a novel mechanism for physiological control of smooth muscle-specific gene expression through extranuclear redistribution of SRF and consequent down-regulation of its transcription-promoting activity.

Animals↗

PubMed2000

Influence of membrane physical state on the lysosomal proton permeability.

Influence of membrane physical state on the proton permeability of isolated lysosomes was assessed by measuring the membrane potential with 3,3'-dipropylthiadicarbocyanine iodide and monitoring their proton leakage with p-nitrophenol. Changes in the membrane order were examined by the steady-state fluorescence anisotropy of 1, 6-diphenyl-1,3,5-hexatriene. Both the membrane potential and proton leakage increased with fluidizing the lysosomal membranes by benzyl alcohol and decreased with rigidifying the membranes by cholesteryl hemisuccinate. The proton permeability increased to the maximum of 42% by the benzyl alcohol treatment and decreased to the minimum of 38.1% by the cholesteryl hemisuccinate treatment. Treating the lysosomes with protonophore CCCP increased the proton permeability by 58%. The effects of the membrane fluidization and rigidification can be reversed by rigidifying the fluidized membranes and fluidizing the rigidified membranes, respectively. The results indicate that the proton permeability of lysosomes increased and decreased with increasing and decreasing their membrane fluidity, respectively. Moreover, the lysosomal proton permeability did not alter further if the changes, either an increase or a decrease, in the fluidity exceeded some amount. The results suggest that the proton permeability of lysosomes can be modulated finitely by the alterations in their membrane physical state.

Animals↗

PubMed2000

The complete cDNA sequence of a type II Trichomonas vaginalis virus.

Trichomonas vaginalis viruses (TVV), which may regulate P270 gene expression in the protozoan pathogen T. vaginalis, are a group of divergent double-stranded (ds) RNA viruses. In the present study, the complete 4674-bp cDNA sequence of a 4.6-kb ds RNA from a newly identified TVV2-1 isolate was determined. The sequence of the plus-strand mRNA contains four open reading frames, which encode overlapping cap and pol genes in the reading frame 2 and reading frame 1, respectively, and two putative serine-threonine-rich basic proteins VP3 and VP4 in the third reading frame. An 85-kDa capsid protein and a 160-kDa CAP-POL fusion protein were identified in crude viruses by Western blotting experiments using antisera raised against gene-specific oligopeptides. In conjunction with the presence of a potential ribosomal slippery heptanucleotide G GGC CCC within the overlap of the cap and pol genes, these observations suggest that the pol gene of TVV2-1 is translated via a -1 ribosomal frameshifting event during translation of the cap gene. Our results also provide insight into the conservation among divergent dsRNA species from TVV and suggest that the genome of TVV2-1 may encode two extra genes in addition to the cap and pol genes.

Amino Acid Sequence↗

PubMed2000

Lysophosphatidylcholine induces apoptotic and non-apoptotic death in vascular smooth muscle cells: in comparison with oxidized LDL.

Oxidized low-density lipoprotein (oxLDL) plays a key role in the development of atherogenesis, partly by causing injury to vascular cells. However, different preparations of LDL, methods of oxidation, and/or active components often produce cellular effects of various degrees. To explore the quantitative relationship between dose and level of oxidation of the oxLDL utilized, we employed combinations of different levels of oxidation and concentrations of oxLDL to induce cell death in cultured vascular smooth muscle cells (VSMC). We also examined the effect of lysophosphatidylcholine (lysoPC), a putative active component of oxLDL, on VSMCs by determining, in parallel with a cytotoxicity test (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay), DNA fragmentation ([3H]thymidine release), and flow cytometric analyses. We found that oxLDL caused cytotoxicity in an oxidative level- and dose-dependent manner, lysoPC also caused dose-dependent cytotoxicity with or without serum. Fragmentation of DNA was observed in both oxLDL- and lysoPC-treated VSMCs. Furthermore, lysoPC-induced DNA ladder was also demonstrated by gel electrophoresis at a concentration of 25 micromol/l or higher. Flow cytometric analysis yielded similar results for oxLDL- and lysoPC-treated VSMC; namely, an accumulation in the fraction of cells in G(0)/G(1) phase with a reciprocal change in S-phase fraction. Membrane phosphatidylserine exposure, detected by annexin V staining, provided additional evidence that lysoPC induced significant apoptosis in VSMC. Taken together, the degree of oxLDL-induced cytotoxicity/apoptosis of VSMC depended on combined effects of oxLDL concentration and oxidative level. Moreover, lysoPC also elicited a dose-dependent apoptosis in addition to cytotoxicity.

Animals↗

PubMed2000

Serum alanine aminotransferase levels in relation to hepatitis B and C virus infections among drug abusers in an area hyperendemic for hepatitis B.

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are the major agents responsible for hepatitis in Taiwan. The purpose of this study was to assess the serum alanine aminotransferase (ALT) activity in relation to HBV and HCV infection among drug abusers. This survey included 769 male drug abusers aged 14-59 years, from the Kaohsiung Narcotic Abstention Institute and Kaohsiung Prision. The prevalence of HBsAg seropositivity was 21.5%, and anti-HCV seropositivity was 27.2%, respectively. Drug abusers with HBsAg or anti-HCV had higher serum AST and ALT levels than those without HBsAg and anti-HCV. The prevalence of raised ALT and AST (> or =45 IU/liter) in the HCV-positive group was more significant than in the negative group, while that of the HBsAg-positive group did not reach statistical significance. Among the HCV-positive group, ALT levels are more closely associated with HCV infection than AST levels. Our results indicated that HCV infection plays an important role in the etiology of raised ALT activity among drug abusers, while HBV infection plays a minor role. ALT screening still remains a simple and valuable method in the early recognition of HCV infection.

Adolescent↗

PubMed2000

Height, weight, and body mass index of elderly persons in Taiwan.

BACKGROUND: In Taiwan, distributions of body composition are usually generated for children, adolescent, and middle-aged groups. This study describes three anthropometric measures (i.e., height, weight, and body mass index [BMI]) of elderly persons in Taiwan. METHODS: The data was derived from a prospective cross-sectional, population-based geriatric survey funded by the National Department of Health in Taiwan in 1991. A total of 2,600 subjects were successfully evaluated. A descriptive analysis was performed to generate distributions of height, weight, and BMI of elderly persons. Based on these descriptive data, the prevalence of overweight and obesity was estimated, and a cross-national comparison on the prevalence of obesity was made. RESULTS: Age-group-specific means and standard deviations for height, weight, and BMI of Taiwanese elderly persons were presented. By gender, the elderly men were taller and heavier than the elderly women: however, the women had a higher mean value of BMI (kg/m2). The prevalence of overweight was 27.3% in men and 34.9% in women; the prevalence of obesity was 3.2% in men and 6.4% in women. The prevalence of obesity for the elderly men and women in Taiwan was lower than in Kuwait, Sweden, the United States, and the Native Americans, but higher than in Japan. CONCLUSIONS: The comparison indicates cross-cultural differences existing in the prevalence of obesity, which may be due to aging, nutritional status, or environmental factors. For future research, the relationship of anthropometric data to socioeconomic status and behavioral factors will be examined.

Aged↗

PubMed2000

GP-83 and GP-39, two glycoproteins secreted by human epididymis are conjugated to spermatozoa during maturation.

Surface glycoconjugates of spermatozoa are modified during epididymal maturation, which is closely related to the development of sperm function. In addition, recognition of surface glycoconjugates is one of very critical events in sperm-oocyte interaction. The binding of carbohydrate-specific lectins to the human sperm surface during epididymal maturation has been investigated. However, the glycoproteins responsible for lectin binding in sperm maturation are not well documented. This study used wheat germ agglutinin (WGA), peanut agglutinin (PNA) and concanavalin A (Con-A) to identify sperm maturation-related glycoproteins in human epididymis. Histochemical localization revealed that the binding sites of WGA, PNA and Con-A were mainly in the principal cells and luminal contents of the human epididymis, but not in the interstitial regions. Each lectin displayed a fairly distinct regional localization. On Western blots probed with WGA and Con-A, glycoproteins of 83 kDa (GP-83) and 39 kDa (GP-39) were identified in the sperm extracts, epididymal fluid and tissue extracts of the corpus and cauda epididymides, but not in the caput. PNA identified GP-83 in the same manner as WGA and Con-A, but did not recognize GP-39. These results suggest that lectin-binding glycoproteins GP-83 and GP-39 found on mature spermatozoa may be secreted by the principal cells of corpus and cauda epididymis, and conjugated to spermatozoa during their transit in human epididymis.

Binding Sites↗

PubMed2000

Purification of GP-83, a glycoprotein secreted by the human epididymis and conjugated to mature spermatozoa.

Epididymal secretions are critical for mammalian spermatozoa to acquire both forward motility and an ability to recognize and penetrate oocytes. Previous studies identified two glycoproteins, GP-83 and GP-39, which were secreted by the human epididymis and may be related to maturation of sperm function. In this study, GP-83 was purified from human seminal fluid by DEAE-ion exchange, gel filtration chromatography and preparative gel elution. The isoelectric point (pI) of purified GP-83 was 6.57. Monospecific antiserum to GP-83 was induced in male New Zealand rabbits and confirmed on immunoblots. GP-83 was found in fluid, tissue and sperm extracts of corpus and cauda epididymis, but not in the caput. Immunohistochemical localization identified GP-83 in the luminal contents and in the supranuclear region and cell membrane of principal cells of the corpus and cauda epididymis. GP-83 was found on the anterior acrosome in ejaculated spermatozoa, and shifted to the equatorial region after capacitation and the acrosome reaction.

Acrosome Reaction↗

PubMed2000

Mutagenesis analysis of human SM22: characterization of actin binding.

SM22 is a 201-amino acid actin-binding protein expressed at high levels in smooth muscle cells. It has structural homology to calponin, but how SM22 binds to actin remains unknown. We performed site-directed mutagenesis to generate a series of NH(2)-terminal histidine (His)-tagged mutants of human SM22 in Escherichia coli and used these to analyze the functional importance of potential actin binding domains. Purified full-length recombinant SM22 bound to actin in vitro, as demonstrated by cosedimentation assay. Binding did not vary with calcium concentration. The COOH-terminal domain of SM22 is required for actin affinity, because COOH terminally truncated mutants [SM22-(1-186) and SM22-(1-166)] exhibited markedly reduced cosedimentation with actin, and no actin binding of SM22-(1-151) could be detected. Internal deletion of a putative actin binding site (154-KKAQEHKR-161) partially prevented actin binding, as did point mutation to neutralize either or both pairs of positively charged residues at the ends of this region (KK154LL and/or KR160LL). Internal deletion of amino acids 170-180 or 170-186 also partially or almost completely inhibited actin cosedimentation, respectively. Of the three consensus protein kinase C or casein kinase II phosphorylation sites in SM22, only Ser-181 was readily phosphorylated by protein kinase C in vitro, and such phosphorylation greatly decreased actin binding. Substitution of Ser-181 to aspartic acid (to mimic serine phosphorylation) also reduced actin binding. Immunostains of transiently transfected airway myocytes revealed that full-length NH(2)-terminal FLAG-tagged SM22 colocalizes with actin filaments, whereas FLAG-SM22-(1-151) does not. These data confirm that SM22 binds to actin in vitro and in vivo and, for the first time, demonstrate that multiple regions within the COOH-terminal domain are required for full actin affinity.

Actins↗

PubMed2000

Preliminary report on the effect of Nd: YAG laser irradiation on canine tooth pulps.

OBJECTIVE: To study the effects of Nd: YAG laser irradiation on the canine tooth pulps. METHODS: The crown pulp of dog was exposed and excised by ND: YAG laser irradiation. Histopathological examination was used to check changes of the tissues in root canal and periodontium. RESULTS: The pulp of the crown could be successfully excised by Nd: YAG laser without harmful changes in either root canal or periodontal tissues. CONCLUSION: This study may provide an experimental basis for the clinical possibility of crown pulp excision by using Nd: YAG laser irradiation.

Aluminum Silicates↗

PubMed2000

Comparison of appendectomy medical expense and clinical outcome between fee for service and prospective payment system.

Since the introduction of national health insurance on March 1st 1995 in Taiwan, another 9 items (including appendectomy) were introduced into the Taiwan/prospective payment system (T/PPS). The modified T/PPS was based on those complicated appendectomy cases with secondary diagnosis or second operation where a total fee over 37,500 New Taiwan (NT) dollars was paid by National Health Insurance Bureau (NHIB) according to the real cost. The T/PPS was implemented in October 1997 due to the continuously increasing financial burden of medical expenses on the NHIB. The purpose of this study is (1) to compare the length of stay (LOS) and total medical expense of appendectomy of fee for service (FFS) and T/PPS and (2) to compare the clinical outcome of wound healing after discharge of the two systems by telephone interview. Our study investigated 100 consecutive appendectomy cases under FFS payment system and 99 consecutive appendectomy cases under T/PPS. We retrospectively analyzed LOS, operation time, and hospital cost of different items through chart review and computer data. Our results revealed that the LOS and operation time of T/PPS were significantly shorter than those of FFS (both p < 0.01). The total hospital cost, fee for room service, treatment, pharmacy, examination and anesthesia in T/PPS were also significantly less than those in FFS (all p < 0.01, except for anesthesia p < 0.05). There existed positive correlation between total hospital cost and LOS, operation time, fee for room service, treatment, pharmacy, examination and anesthesia both for T/PPS and FFS. To evaluate the clinical outcome of appendectomy between T/PPS and FFS, we interviewed 73 T/PPS cases and 73 FFS cases by telephone and chart review. Our results revealed that there were no significant differences in frequencies of having painful incision, clear incision wound on the day of discharge, and removal of stitches at hospital (p all > 0.05). We concluded that compared to FFS, T/PPS can decrease LOS and total hospital cost of appendectomy, and T/PPS's clinical outcome of appendectomy in T/PPS showed no significant difference from that in FFS.

Adult↗

PubMed2000

[Enantiomer separation by capillary electrochromatography].

As capillary electrochromatography (CEC) combines the desirable features of both high performance liquid chromatography(HPLC) and high performance capillary electrophoresis(HPCE), CEC is an attractive alternative for enantiomer separation. The applications and developments in the field of chiral drug separation by CEC are reviewed with 92 references, including different operating models and different chiral agents and stationary phases.

Adrenergic beta-Antagonists↗

PubMed2000

[Determination of catechins in grape seeds by capillary electrophoresis].

A capillary zone electrophoresis (CZE) method has been developed for the determination of four pharmacologically active catechins in grape seed. The components analyzed were (+)-catechin, (-)-epicatechin, epigallocatechin and epicatechin gallate. Separation was achieved by using a mixed buffer of 0.02 mol/L borate and 0.005 mol/L phosphate at pH 10.0 as background electrolyte and an uncoated fused silica capillary with 50 microns i.d. x 375 microns o.d. (effective length 41.5 cm) maintained at 25 degrees C. The applied voltage was 25 kV, and detection was performed by DAD at wavelength of 210 nm. By using proposed CZE method, four catechins were well separated within only 10 minutes with the repeatability of < 1% RSD for migration time and < 5% RSD for peak area. Correlation coefficients better than 0.995 were obtained within the concentration range from 0.005 g/L to 0.5 g/L for the four analytes studied with the detection limit of 3 mg/L-10 mg/L. The contents of these compounds in ten species of grape seeds cultivated in China were successfully determined.

Catechin↗