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Biomedical subjects

J F Huang

Publications and source records attributed to J F Huang.

At least 37 records · Page 2Linked to original sources
PubMed1998

Protein three-dimensional structural databases: domains, structurally aligned homologues and superfamilies.

This paper reports the availability of a database of protein structural domains (DDBASE), an alignment database of homologous proteins (HOMSTRAD) and a database of structurally aligned superfamilies (CAMPASS) on the World Wide Web (WWW). DDBASE contains information on the organization of structural domains and their boundaries; it includes only one representative domain from each of the homologous families. This database has been derived by identifying the presence of structural domains in proteins on the basis of inter-secondary structural distances using the program DIAL [Sowdhamini & Blundell (1995), Protein Sci. 4, 506-520]. The alignment of proteins in superfamilies has been performed on the basis of the structural features and relationships of individual residues using the program COMPARER [Sali & Blundell (1990), J. Mol. Biol. 212, 403-428]. The alignment databases contain information on the conserved structural features in homologous proteins and those belonging to superfamilies. Available data include the sequence alignments in structure-annotated formats and the provision for viewing superposed structures of proteins using a graphical interface. Such information, which is freely accessible on the WWW, should be of value to crystallographers in the comparison of newly determined protein structures with previously identified protein domains or existing families.

Amino Acid Sequence↗
PubMed1998

A novel calmodulin-regulated Ca2+-ATPase (ACA2) from Arabidopsis with an N-terminal autoinhibitory domain.

To study transporters involved in regulating intracellular Ca2+, we isolated a full-length cDNA encoding a Ca2+-ATPase from a model plant, Arabidopsis, and named it ACA2 (Arabidopsis Ca2+-ATPase, isoform 2). ACA2p is most similar to a "plasma membrane-type" Ca2+-ATPase, but is smaller (110 kDa), contains a unique N-terminal domain, and is missing a long C-terminal calmodulin-binding regulatory domain. In addition, ACA2p is localized to an endomembrane system and not the plasma membrane, as shown by aqueous-two phase fractionation of microsomal membranes. ACA2p was expressed in yeast as both a full-length protein (ACA2-1p) and an N-terminal truncation mutant (ACA2-2p; Delta residues 2-80). Only the truncation mutant restored the growth on Ca2+-depleted medium of a yeast mutant defective in both endogenous Ca2+ pumps, PMR1 and PMC1. Although basal Ca2+-ATPase activity of the full-length protein was low, it was stimulated 5-fold by calmodulin (50% activation around 30 nM). In contrast, the truncated pump was fully active and insensitive to calmodulin. A calmodulin-binding sequence was identified within the first 36 residues of the N-terminal domain, as shown by calmodulin gel overlays on fusion proteins. Thus, ACA2 encodes a novel calmodulin-regulated Ca2+-ATPase distinguished by a unique N-terminal regulatory domain and a non-plasma membrane localization.

Amino Acid Sequence↗
PubMed1998

Diagnosis of hepatocellular carcinoma by quantitative detection of hepatoma-specific bands of serum gamma-glutamyltransferase.

Tissues of hepatocellular carcinoma (HCC) can express hepatoma-specific gamma-glutamyltransferase (GGT) and secrete GGT into circulating blood. Serum GGT was separated into several bands (up to 11), including hepatoma-specific bands (HSBs, I', II, and II') by a vertical slab electrophoresis assay of polyacrylamide stage gradient gel. In the present study, the HSBs of serum GGT were separated, and the HSB activity was quantitatively measured in 91 patients with HCC and compared with that of 106 patients with benign liver disease, 16 patients with extrahepatic tumors, and 30 healthy control subjects. Significant differences of the HSB activity were observed between the HCC group and each study group. An HSB activity greater than 5.5 U/L seems to be diagnostic of HCC. The quantitative method has a sensitivity of 85.3%, a specificity of 97.2%, a positive predictive value of 95.1%, a negative predictive value of 91.2%, and an accuracy of 92.5% for detecting HCC. No correlation was found between HSB activity and the serum alpha-fetoprotein (AFP) level or tumor size in patients with HCC. The quantitative analysis of HSB activity of GGT is superior to detection of the AFP concentration and is useful in early diagnosis of small HCC or AFP-negative HCC.

Adult↗
PubMed1998

Methylation and gene mutation in eukaryotic DNA.

5-methylcytosine (m5C) as a rare base exists in eukaryotic genomes, which is a normal constitution in many eukaryotic DNA and the existence of m5C is a feature of eukaryotic DNA. Under regular physiological conditions, cytosine of eukaryotic DNA is usually methylated. Up to the present, many people consider that the m5C may be mutation hotspots by the deamination leading to gene mutation. Our study indicated that the spontaneous mutation caused by the transition of G.C --> A.T, in eukaryotic DNA, may result from the tautomer changing of base pairs and may also be cause by other factor actions, however it could not be caused by the deamination of m5C.

Base Sequence↗
PubMed1998

[Interleukin-6 production by human gingival fibroblasts following stimulation with Actinobacillus actinomycetemcomitans].

Actinobacillus actinomycetemcomitans(Aa), elaborating a multiplicity of virulence factor and tissue-damaging products, is considered an etiological agent in periodontal disease. Serotype b is the most frequently isolated serotype in localized juvenile periodontitis patients, suggesting a particularly high periodontopathic potential for serotype b strains. Interleukin-6(IL-6) plays an important role in the mediation of inflammatory and immune responses as well as in the osteoclastic bone resorption. However, there is little information regarding the effect of the different serotypes of Aa on IL-6 production by human gingival fibroblasts (HGF). Therefore, the purpose of this study was to compare the ability of the three serotypes (a, b, and c) of Aa sonicates to induce the production of IL-6 by HGF. In fibroblast cultures, confluent monolayers of HGF were incubated with sonic extracts of Aa-511 (serotype a), Aa-Y4 (serotype b), and Aa-652 (serotype c) at various concentrations for 48 h at 37 degrees C in 5% CO2 and air. At the end of the culture period, supernatants were collected and analysed for IL-6 content by using EIA and bioassay. In order to compare the effects of non-lipopolysaccharide (LPS) activation of Aa sonicates on IL-6 production by HGF, we added polymyxin B in cultures with Aa sonicates to bind LPS. The results were summarized as follows. (1) All three serotypes of Aa sonicates had similar dose-dependent stimulant effects on IL-6 production by HGF, and the biological activities of IL-6 correlated with their immunoreactivities. (2) The maximum releases of IL-6 by HGF were achieved at concentrations of 10 to 100 micrograms protein/mL of Aa sonicates, and the ability of Aa-Y4 to induce the release of IL-6 was higher than that of Aa-511 and Aa-652 at these concentrations. (3) Polymyxin B (50 micrograms/mL) effectively decreased the amounts of IL-6 produced by stimulation of the HGF with 10 micrograms protein/mL of Aa sonicates. However, the polymyxin B-treated Aa-Y4 sonicate showed a higher ability to induce the release of IL-6 than the other two strains. These results indicate that Aa-Y4 (serotype b) has a higher potency to induce HGF secretion of IL-6; thus contributing to a comparatively stronger efficacy to the destruction of periodontal tissue in periodontitis.

Adult↗
PubMed1998

Dimethylformamide-induced occupational liver injury--a case report.

Dimethylformamide(DMF), a widely used industrial solvent, has been reported to induce subtle to clinically overt hepatotoxicity. Liver injury due to occupational exposure through inhalation and skin contact have been sporadically reported. We reported a 42-year-old male Taiwanese who developed progressive, intermittent abdominal pain for 6 months after working in a synthetic leather factory. Acute hepatitis episode occurred after working in an enclosed and poorly-ventilated workplace for one day. Based on occupational history, pathological examination and serial liver function examinations, the case was compatible with DMF-induced acute chemical hepatitis.

Adult↗
PubMed1997

Different viral aetiology of hepatocellular carcinoma between two hepatitis B and C endemic townships in Taiwan.

In Taiwan, we found two hepatitis B virus (HBV)- and hepatitis C virus (HCV)-endemic townships, Paisha and Tzukuan, with an anti-HCV prevalence of 19 and 37% in men, and 26 and 38% in women, respectively. The hepatitis B surface antigen (HBsAg)-positive rates were 25 and 18%, for men and women in Paisha, and 25 and 22% in Tzukuan, respectively. According to the national death certification database (1982 to 1991), the annual age-adjusted mortality rates per 100,000 population for liver cancer among men and women were 83.0 and 13.8, respectively, in Paisha, and 55.9 and 17.0 in Tzukuan compared with 30.9 and 9.1 in Taiwan as a whole. The male-to-female ratios were 6.0 in Paisha and 3.3 in Tzukuan. Aetiology of 11 cases of hepatocellular carcinoma (HCC) from Paisha and 14 cases from Tzukuan were analysed. All HCC cases from Paisha were HBsAg positive, while 13/14 HCC cases from Tzukuan were anti-HCV positive. The endemic duration of HCV in Tzukuan seemed long enough to induce HCC, but the HCV appeared to be a newly introduced infection in Paisha.

Adult↗
PubMed1997

Incidence of hepatitis C infection in a hepatitis C endemic township in southern Taiwan.

To realize the incidence of hepatitis C virus (HCV) infection in an HCV endemic township, Tzukuan, in Taiwan, we conducted a follow-up community-based survey. A total of 173 adults, 82 males and 91 females, with mean age of 55.5 +/- 9.9 years received initial and follow-up anti-HCV tests with one-year interval. One (1.2%, 95% CI: 0%-5.5%) of 84 anti-HCV-positive subjects was negative-seroconversion, and 4 (4.5%, 95% CI: 0.2%-8.8%) of 89 anti-HCV-negative subjects were positive-seroconversion. The results indicated that hepatitis C might be still spreading in the HCV-endemic area now.

Adult↗
PubMed1997

Correlation of interleukin-1 beta, interleukin-6, and periodontitis.

In order to understand the role of IL-1 beta and IL-6 in the periodontal tissue destruction coincident to periodontitis, we assessed the levels of these two mediators in both the gingival tissue and the serum of patients with periodontal disease and of periodontally healthy subjects. In addition, production of IL-6 by six healthy human gingival fibroblast (HGF) strains in response to IL-1 beta was also investigated. The levels of IL-1 beta and IL-6 in gingival tissues and in serum were examined by ELISA. Both mediators were observed to increase in diseased tissues of patients with adult periodontitis, and there was a positively significant relationship between both mediators and clinical assessments of periodontal destruction. Moreover, a significant correlation was also noted between levels of IL-1 beta and IL-6 in gingival tissues of periodontitis patients (r = 0.4334, p < 0.01). However, there was no significant difference in the serum levels of IL-1 beta and IL-6 between periodontitis patients and periodontally healthy controls. In fibroblast cultures, confluent monolayers of HGF were incubated with recombinant human IL-1 beta for 48 h at 37 degrees C in 5% CO2 and air. At the end of the culture period, supernatants were collected and assayed for IL-6 activity by inducing proliferation in the IL-6-dependent hybridoma cell line 7TD1. A dose-dependent stimulatory effect of IL-1 beta on IL-6 production by HGF was noted, wherein 3 strains exhibited higher IL-6 activity than the other 3. These data indicate that the levels of IL-1 beta and IL-6 in gingival tissues are closely related to the severity of periodontal disease and that the IL-1 beta and IL-6 produced in gingival tissues may not reflect these two mediators levels in serum. Moreover, IL-1 beta responsiveness of HGF in IL-6 production depends on both the concentration of IL-1 beta and cells of individual subjects. Since HGF are present in periodontal lesion, it is possible that IL-6 secretion stimulated by exposure to inflammatory cell products such as IL-1 beta may participate in the destruction of periodontal tissue in periodontitis.

Adult↗
PubMed1996

Activation of a Ca(2+)-dependent protein kinase involves intramolecular binding of a calmodulin-like regulatory domain.

Ca(2+)-dependent protein kinases (CDPKs) are regulated by a C-terminal calmodulin-like domain (CaM-LD). The CaM-LD is connected to the kinase by a short junction sequence which contains a pseudosubstrate autoinhibitor. To understand how the CaM-LD regulates a CDPK, a recombinant CDPK (isoform CPK-1 from Arabidopsis, accession no. L14771) was made as a fusion protein in Escherichia coli. We show here that a truncated CDPK lacking a CaM-LD (e.g. mutant delta NC-26H) can be activated by exogenous calmodulin or an isolated CaM-LD (Kact approximately 2 microM). We propose that Ca2+ activation of a CDPK normally occurs through intramolecular binding of the CaM-LD to the junction. When the junction and CaM-LD are made as two separate polypeptides, the CaM-LD can bind the junction in a Ca(2+)-dependent fashion with a dissociation constant (KD) of 6 x 10(-6) M, as determined by kinetic binding analyses. When the junction and CaM-LD are tethered in a single polypeptide (e.g. in protein JC-1), their ability to engage in bimolecular binding is suppressed (e.g. the tethered CaM-LD cannot bind a separate junction). A mutation which disrupts the putative CaM-LD binding sequence (e.g. substitution LRV-1444 to DLPG) appears to block intramolecular binding, as indicated by the restored ability of a tethered CaM-LD to engage in bimolecular binding. This mutation, in the context of a full-length enzyme (mutant KJM46H), appears to block Ca2+ activation. Thus, a disruption of intramolecular binding correlates with a disruption of the Ca2+ activation mechanism. CDPKs provide the first example of a member of the calmodulin superfamily where a target binding sequence is located within the same polypeptide.

Amino Acid Sequence↗
PubMed1996

[The influential factors of formation and development of personality in children with congenital heart disease].

106 children with congenital heart disease (CHD) were tested by the Eysenck personality Questionaire (EPQ) and the Psychological Monitor Card in this study. The result showed that the personality of the CHD children is more introversive and moody than that of normal children. The influential factors including disease, family, and society were analysed. It suggested that it is important to provide psychological support to the CHD children and psychological knowledge to the parents.

Child↗
PubMed1996

[The effect of adaptive behavior training on rehabilitation of children with congenital heart disease].

The adaptation behaviors of 102 children with congenital heart disease were assessed by Children's Adaptation Behaviors Scale. The result indicated that behavior training should be given according to their adaptive behaviors before operation. 106 children with congenital heart disease were divided into two groups. 67 were in behavior training group and 39 were in control group. The result showed that self-care abilities and compliance of therapeutic regimen of the training group were much better than that of the control group. The length of stay in the hospital of the training group was 3.01 days shorter than that of the control group.

Adaptation, Psychological↗
PubMed1996

[The effect of rehabilitation training on postoperative recovery of children with congenital heart disease].

In this study, seven stages rehabilitation exercise were set up according to the rehabilitation training principles. 83 post-operative congenital heart disease children whose age ranging from 4 approximately 12 years were divided into two groups. The results showed that there was a significant difference between rehabilitation training group and control group in the time of ventilator weaning, intensive care, and mean hospitalization. The time of ventilator wearing was 7.34 hours shorter in the study group than that of control group. The time of under intensive care and hospitalization were also 2.04 days and 3.24 days shorter respectively. It is suggested that rehabilitation training has a good effect on post-operative children with congenital heart disease.

Child↗
PubMed1995

A molecular model of braid-like DNA structure.

The three-dimensional molecular models of DNA triple helices and triple-stranded brain-like structure were built up by molecular architecture, and their structural features and energy decomposition were examined. The results showed: (i) The base triplet is the element forming braid-like and triple helix DNA; (ii) Under specified conditions, DNA could form the triplet-stranded braid-like structure; (iii) DNA stability of the braid-like structure is less than that of the triple helix structure.

Bacteriophage lambda↗
PubMed1995

Portal vein embolization with ethanol injection via a fine needle in dogs.

We devised a method for portal vein embolization with ethanol injection (PVEEI) via a fine needle. Both the efficacy and safety of this procedure were evaluated in 28 dogs. An embolization of the left central and lateral lobes was undertaken with various doses of absolute (95%) ethanol. The smallest dose, 0.25 ml/kg ethanol (n = 7), caused the least damage to the liver, but the embolization was not complete. At the highest dose at 1.0 ml/kg, four of the seven dogs died of respiratory arrest; however, embolization was complete in the remaining dogs. All animals tolerated the procedure by 0.5 ml/kg ethanol (n = 11) with a satisfactory embolic effect, slight toxicity to the hepatic parenchyma, and only transient changes in liver function. The results suggested that PVEEI is safe and effective when a suitable dose of ethanol is administered. Local overembolization occurred in one dog due to extension of the thrombus, suggesting that the point of puncture should not be near the confluence of the branches. Since a selective portal venous puncture is not difficult to perform under sonographic guidance, PVEEI is expected to be clinically applied.

Animals↗
PubMed1995

In vitro production of interleukin-6 by human gingival, normal buccal mucosa, and oral submucous fibrosis fibroblasts treated with betel-nut alkaloids.

This study aimed to assess the possibility of a direct effect of betel-nut alkaloids arecoline and arecaidine on cell proliferation and interleukin-6 (IL-6) production by cultured fibroblasts from human normal gingiva, buccal mucosa and oral submucous fibrosis (OSF) buccal mucosa in vitro. Confluent monolayers of fibroblasts were incubated with or without alkaloids in the presence of 10% fetal calf serum for 48 h at 37 degree C in 5% CO2 and air. At the end of the culture period, supernatants were collected and assayed for IL-6 level. The cell proliferation was monitored by determining 5-bromo-2'-deoxy-uridine (BrdU) incorporated into cellular DNA. Except for the fact that arecoline inhibited cell growth at 100 micrograms/ml, arecoline and arecaidine had similar dose-dependent stimulant effects on the proliferation of these three groups fibroblasts. Concentrations of IL-6 in the control culture supernatants were greatest in healthy gingival fibroblasts, followed by normal buccal mucosa and OSF. Also, the presence of fetal calf serum could stimulate IL-6 release. Except for arecoline at the 100 microgram/mg, there were no significant differences in IL-6 levels between treated and control cultures of the same group when the data were expressed with mean +/- S.D.. However, two of six individuals' normal buccal mucosa fibroblasts significantly released less IL-6, and some cases of OSF and healthy gingiva exhibited slightly higher levels of IL-6 when cells were exposed to arecoline or arecaidine in cultures. Such findings suggests that arecoline and arecaidine can enhance cell proliferation and affect fibroblasts to synthesize IL-6. Furthermore, IL-6 may be a contributing molecular factor in the pathological features noted in OSF.

Adult↗
PubMed1995

Prevalence and size of simple hepatic cysts in Taiwan: community- and hospital-based sonographic surveys.

Simple hepatic cysts are now being diagnosed more frequently with the widespread availability of sonographic imaging. Among the general population, the prevalence was reported to be between 0.1 and 2.5%, more so in women, and more often in the right lobe. We conducted this large scale community-based sonographic screening on simple hepatic cysts to explore the age- and sex-specific prevalence in Taiwan. We also conducted another hospital-based study to record the size of simple hepatic cysts. A total of 3,600 subjects in 8 communities were recruited and 156 simple hepatic cysts in 132 study subjects were detected. The overall prevalence is 3.60%. An increasing prevalence with age is demonstrated, ranging from 0.83% from below the age of 40 up to 7.81% of patients over 60 years old. The sizes of 219 simple hepatic cysts of 167 patients out of the hospital-based 5,893 patients were recorded in detail; 53% of cysts were of a diameter of between 1 and 3 cm, and only 7% were larger than 5 cm.

Adult↗