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C Hou

Publications and source records attributed to C Hou.

At least 19 recordsLinked to original sources
PubMed2005

Chemical ablation of the gallbladder: clinical application and long-term observations.

BACKGROUND: We investigated whether minicholecystostomy followed by chemical ablation of the gallbladder could be used as a alternative to cholecystectomy in patients at high risk for complications of surgery. METHODS: From January 1990 through January 2003, 34 patients at high risk underwent minicholecystostomy. Six weeks after the operation, microwave irradiation was provided to burn the mucosa of the cystic duct at locations at 3, 6, 9, and 12 o'clock around the orifice. Each location was treated eight times at 50 mA for 10 sec. Then chemical ablation of the gallbladder was performed by infusing 95% ethanol into the gallbladder cavity for 30 min. For each sclerosis course, the procedure was repeated every 4 h for a total of eight times. Approximately 2 weeks later, the drainage tube was removed from the gallbladder after cholecystography showed that no cavity other than the lumen of the tube remained in the gallbladder. RESULTS: Patients tolerated the procedure well and were followed with ultrasonography for 2-14 years (mean, 9). Twenty-nine patients had no complications or side effects, and five patients developed a 1.5- to 3- cm mucocele in the gallbladder. The long-term success rate of sclerotherapy was 85.3% (29/34). No recurrent cholecystitis, new stone or formation, canceration were encountered at the site of the gallbladder. CONCLUSIONS: Minicholecystostomy followed by chemical ablation of the gallbladder was a safe, effective, and simple procedure for treating high-risk patients with acute cholecystitis and/or cholelithiasis.

Aged↗
PubMed2005

Haplotypic association spanning the 22q11.21 genes COMT and ARVCF with schizophrenia.

Catechol-O-methyltransferase (COMT) has been implicated in schizophrenia by its function through its roles in monoamine neurotransmitter metabolism and its impact on prefrontal cognition, and also by its position through linkage scans and a strong cytogenetic association. Further support comes from association studies, especially family-based ones examining the COMT variant, Val(108/158)Met. We have studied eight markers spanning COMT and including portions of the two immediately adjacent genes, thioredoxin reductase 2 and armadillo repeat deleted in velocardiofacial syndrome (ARVCF), using association testing in 136 schizophrenia families. We found nominal evidence for association of illness to rs165849 (P=0.051) in ARVCF, and a stronger signal (global P=0.0019-0.0036) from three-marker haplotypes spanning the 3' portions of COMT and ARVCF, including Val(108/158)Met with Val(108/158) being the overtransmitted allele, consistent with previous studies. We also find Val(108/158)Met to be in linkage disequilibrium with the markers in ARVCF. These findings support previous association signals of schizophrenia to COMT markers, and suggest that ARVCF might contribute to this signal. ARVCF, a member of the catenin family, besides being a positional candidate, is also one due to its function, that is, its potential role in neurodevelopment, which is implicated in schizophrenia pathogenesis by several lines of evidence.

Adult↗
PubMed2002

The prevalence of TT virus and GB virus C/hepatitis G virus infection in individuals with raised liver enzymes but without HBV or HCV infection in Taiwan.

The prevalence of TT virus (TTV) and GB virus-C/hepatitis G virus (GBV-C/HGV) infection and the association with raised liver function tests in 546 Taiwanese with negative HBsAg, anti-HCV and HCV RNA was elucidated. They were tested for serum alanine aminotransferase (ALT), GBV-C/HGV RNA, anti-envelope protein 2 antibody (anti-E2) and TTV DNA. Direct sequencing and phylogenetic analyses were performed on 58 isolates for TTV genotype determination. The prevalence of TTV DNA, GBV-C/HGV RNA, anti-E2 and over all GBV-C/HGV exposure was 24.9, 3.4, 8.2 and 11.1%, respectively. Using uni- and multi-variate analyses, male gender and TTV viremia were associated significantly with raised ALT values. Sixty-nine percent of TTV isolates were deduced to be TTV genotype 1 and they had significantly lower mean age than genotype non-1 isolates. In the population, raised ALT may be related to male gender and be attributable to TTV infection but not to GBV-C/HGV among individuals with no evidence of current HBV and HCV infection. TTV genotype 1 is the most prevalent genotype and associated with younger age.

Adult↗
PubMed2001

Properties of a proton-translocating nicotinamide nucleotide transhydrogenase from Escherichia coli with alpha and beta subunits linked through fused transmembrane helices.

Proton-translocating nicotinamide nucleotide transhydrogenase from Escherichia coli is composed of an alpha and a beta subunit, whereas the homologues mitochondrial enzyme contains a single polypeptide. As compared to the latter transhydrogenase, using a 14-helix model for its membrane topology, the point of fusion is between the transmembrane helices 4 and 6 where the fusion linker provides the extra transmembrane helix 5. In order to clarify the potential role of this extra helix/linker, the alpha and the beta subunits were fused using three connecting peptides of different lengths, one (pAX9) involving essentially a direct coupling, a second (pKM) with a linking peptide of 18 residues, and a third (pKMII) with a linking peptide of 32 residues, as compared to the mitochondrial extra peptide of 27 residues. The results demonstrate that the plasma membrane-bound and purified pAX9 enzyme with the short linker was partly misfolded and strongly inhibited with regard to both catalytic activities and proton translocation, whereas the properties of pKM and pKMII with longer linkers were similar to those of wild-type E. coli transhydrogenase but partly different from those of the mitochondrial enzyme although pKMII generally gave higher activities. It is concluded that a mitochondrial-like linking peptide is required for proper folding and activity of the E. coli fused transhydrogenase, and that differences between the catalytic properties of the E. coli and the mitochondrial enzymes are unrelated to the linking peptide. This is the first time that larger subunits of a membrane protein with multiple transmembrane helices have been fused with retained activity.

Amino Acid Sequence↗
PubMed2001

Isomerization of (Z,Z) to (E,E)1-bromo-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene in strong base: probes for amyloid plaques in the brain.

In developing probes for detecting beta-amyloid (Abeta) plaques in the brain of Alzheimer's disease (AD), we have synthesized 1-bromo-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (5, BSB). Due to the presence of two double bonds, formation of four different isomers is possible. Four isomers, E,E-5, E,Z-5, Z,E-5, and Z,Z-5, were prepared. Surprisingly, all showed strong fluorescent labeling of Abeta plaques in the brain of postmortem brain sections of patients with confirmed AD. In vitro binding assay also showed that all four isomers of BSB (E,E-5, E,Z-5, Z,E-5, and Z,Z-5) displayed a similar high binding affinity inhibiting the binding of [(125)I]E,E-6, 1-iodo-2,5-bis-(3-hydroxycarbonyl-4-methoxy)styrylbenzene (IMSB) to Abeta(1-40) aggregates. The inhibition constants (K(i)) of E,E-5, E,Z-5, Z,E-5, and Z,Z-5 were 0.11 +/- 0.01, 0.19 +/- 0.03, 0.27 +/- 0.06, and 0.13 +/- 0.02 nM, respectively. Due to the fact that geometric stability of these styrylbenzenes is unknown, and the conversion of Z,Z-5 to E,E-5 may occur automatically in the binding or labeling assaying conditions, we have investigated the kinetics of conversion of Z,Z-5 to E,E-5 by NMR in D(2)O/NaOD at elevated temperatures (70, 95, and 115 degrees C). The activation energy was determined to be 14.15 kcal/mol. The results strongly suggest that the isomeric conversion at room temperature in aqueous buffer solution is unlikely. All of the styrylbenzene isomers clearly showed potential as useful tools for studying Abeta aggregates in the brain. The data suggest that, despite the rigidity of this series of styrylbenzenes, the binding sites on Abeta aggregates may have certain flexibility and the binding pockets could be adaptable for binding to other smaller ligands. Such information could be exploited to develop new ligands for detecting amyloid plaques in AD.

Alzheimer Disease↗
PubMed2001

Radioiodinated styrylbenzenes and thioflavins as probes for amyloid aggregates.

We report for the first time that small molecule-based radiodiodinated ligands, showing selective binding to Abeta aggregates, cross the intact blood-brain barrier by simple diffusion. Four novel ligands showing preferential labeling of amyloid aggregates of Abeta(1-40) and Abeta(1-42) peptides, commonly associated with plaques in the brain of people with Alzheimer's disease (AD), were developed. Two 125I-labeled styrylbenzenes, (E,E)-1-iodo-2,5-bis(3-hydroxycarbonyl-4-hydroxy)styrylbenzene, 12 (ISB), and (E,E)-1-iodo-2,5-bis(3-hydroxycarbonyl-4-methoxy)styrylbenzene, 13 (IMSB), and two 125I-labeled thioflavins, 2-[4'-(dimethylamino)phenyl]-6-iodobenzothiazole, 18a (TZDM), and 2-[4'-(4''-methylpiperazin-1-yl)phenyl]-6-iodobenzothiazole, 18b (TZPI), were prepared at a high specific activity (2200 Ci/mmol). In vitro binding studies of these ligands showed excellent binding affinities with Kd values of 0.08, 0.13, 0.06, and 0.13 nM for aggregates of Abeta(1-40) and 0.15, 0.73, 0.14, and 0.15 nM for aggregates of Abeta(1-42), respectively. Interestingly, under a competitive-binding assaying condition, different binding sites on Abeta(1-40) and Abeta(1-42) aggregates, which are mutually exclusive, were observed for styrylbenzenes and thioflavins. Autoradiography studies of postmortem brain sections of a patient with Down's syndrome known to contain primarily Abeta(1-42) aggregates in the brain showed that both [(125)I]18a and [125I]18b labeled these brain sections, but [125I]13, selective for Abeta(1-40) aggregates, exhibited very low labeling of the comparable brain section. Biodistribution studies in normal mice after an iv injection showed that [125I]18a and [(125)I]18b exhibited excellent brain uptake and retention, the levels of which were much higher than those of [125I]12 and [125I]13. These findings strongly suggest that the new radioiodinated ligands, [125I]12 (ISB), [125I]13 (IMSB), [125I]18a (TZDM), and [125I]18b (TZPI), may be useful as biomarkers for studying Abeta(1-40) as well as Abeta(1-42) aggregates of amyloidogenesis in AD patients.

Alzheimer Disease↗
PubMed2001

Characterization of mutants of beta histidine91, beta aspartate213, and beta asparagine222, possible components of the energy transduction pathway of the proton-translocating pyridine nucleotide transhydrogenase of Escherichia coli.

The roles of three residues (betaHis91, betaAsp213, and betaAsn222) implicated in energy transduction in the membrane-spanning domain II of the proton-translocating pyridine nucleotide transhydrogenase of Escherichia coli have been examined using site-directed mutagenesis. All mutations affected transhydrogenation and proton pumping activities, although to various extents. Replacing betaHis91 or betaAsn222 of domain II by the basic residues lysine or arginine resulted in occlusion of NADP(H) at the NADP(H)-binding site of domain III. This was not seen with betaD213K or betaD213R mutants. It is suggested that betaHis91 and betaAsn222 interact with betaAsp392, a residue probably involved in initiating conformational changes at the NADP(H)-binding site in the normal catalytic cycle of the enzyme (M. Jeeves et al. (2000) Biochim. Biophys. Acta 1459, 248-257). The introduced positive charges in the betaHis91 and betaAsn222 mutants might stabilize the carboxyl group of betaAsp392 in its anionic form, thus locking the NADP(H)-binding site in the occluded conformation. In comparison with the nonmutant enzyme, and those of mutants of betaAsp213, most mutant enzymes at betaHis91 and betaAsn222 bound NADP(H) more slowly at the NADP(H)-binding site. This is consistent with the effect of these two residues on the binding site. We could not demonstrate by mutation or crosslinking or through the formation of eximers with pyrene maleimide that betaHis91 and betaAsn222 were in proximity in domain II.

Amino Acid Sequence↗
PubMed2001

[Diagnosing complicated congenital heart disease with two-dimensional echocardiography and three-segment concept].

OBJECTIVE: To apply three-segment heart anatomy concept to two-dimensional echocardiography (2DE) in the diagnosis of complicated congenital heart disease (CHD). METHODS: 920 cases of CHD were diagnosed with 2DE and three-segment heart anatomy concept. 822 out of the 920 cases underwent angiocardiography, and 584 cases were confirmed by operation. RESULTS: According to three-segment heart anatomy concept of atrial position, 855 cases were situs solitus (including 89 cases of left superior vena cava and 31 cases of complete anomalous pulmonary venous drainage), 53 cases were situs inversus, and 12 cases were situs ambigus. As to atrial-ventricular valve, 747 cases were both opening, 112 cases had one-side atresia, and 61 cases had one together valve; As to ventricle position, 606 cases were dextro-loop, 111 cases had levo-loop, and 203 cases had single ventricle (including 24 cases), As to cor biloculare of great artery relation, 304 cases had normal relation of great arteries, including 35 cases of pulmonary atresia, 219 cases had right-transposition of great arteries, 240 cases had left-transposition of great arteries, 32 cases were mirror to normal, and 25 cases had persistent truncus arteriosus. 823 cases were diagnosed with 2DE, with a total accurate rate of 89.5%. CONCLUSION: Applying three-segment heart anatomy concept to 2DE to diagnose complicated CHD and analyzing the heart segment by segment will make the diagnosis simple and systematic, providing a concise basis for heart surgeries.

Adolescent↗
PubMed2001

Intersubunit crosslinking of the heterotetrameric proton-translocating pyridine nucleotide transhydrogenase of Escherichia coli defines intersubunit contacts between transmembrane helices of the beta subunits.

The proton-translocating pyridine nucleotide transhydrogenase of Escherichia coli is composed of two types of subunits, alpha and beta, organized as an alpha(2)beta(2) tetramer. The protein contains three recognizable domains, of which domain II is the transmembrane region of the molecule containing the pathway for proton translocation. Domain II is composed of four transmembrane helices at the carboxyl-terminus of the alpha subunit and nine transmembrane helices at the amino-terminal region of the beta subunit. We have introduced pairs of cysteine residues into all of the loops connecting the transmembrane helices of domain II of the beta subunit. Crosslinking between the two beta subunits of the tetramer was induced spontaneously, or by treatment with cupric 1,10-phenanthrolinate or o-phenylenedimaleimide. Crosslinks between pairs of betaA114C, betaS183C, and betaA262C residues were observed, suggesting that pairs of domain II transmembrane helices 11, 12, and 14 were in proximity. These results, together with previous data (Bragg and Hou (2000) Biochem. Biophys. Res. Commun. 273, 955-959) suggest that the transhydrogenase tetramer is formed by apposition of alpha(2) and beta(2) dimers. Crosslinking between pairs of cysteine residues in the same beta subunit was not observed, possibly because the interhelical loops of the domain II region of the beta subunit were too short to allow correct orientation of the sulfhydryl groups for crosslinking.

Amino Acid Sequence↗
PubMed2001

IBOX(2-(4'-dimethylaminophenyl)-6-iodobenzoxazole): a ligand for imaging amyloid plaques in the brain.

It is well known that overproduction and accumulation of beta-amyloid (Abeta) plaques in the brain is a key event in the pathogenesis of Alzheimer's disease (AD). Previously it was demonstrated that [125I]TZDM, 2-(4'-dimethylaminophenyl)-6-iodobenzothiazole, a thioflavin derivative, was an effective ligand with good in vitro and in vivo binding characteristics. To further improve the initial uptake and washout rate from the brain, important properties for in vivo imaging agents, a novel radioiodinated ligand, 2-(4'-dimethylaminophenyl)-6-iodobenzoxazole ([125I]IBOX, 3), for detecting Abeta plaques in the brain, was synthesized and evaluated. The new iodinated ligand, IBOX, is based on an isosteric replacement of a sulfur atom of TZDM by an oxygen, by which the molecular weight is reduced while the lipophilicity of the iodinated ligand is increased. Partition coefficients (P.C.) of these two ligands were 70 and 124 for TZDM and IBOX, respectively. In vitro binding study indicated that the isosteric displacement yielded a new ligand with equal binding potency to Abeta(1-40) aggregates (K(i) = 1.9 and 0.8 nM for TZDM and IBOX, respectively). Autoradiography of postmortem brain sections of a confirmed AD patient by [125I]IBOX showed excellent labeling of plaques similar to that observed with [125I]TZDM. More importantly, in vivo biodistribution of [125I]IBOX in normal mice displayed superior peak brain uptake (2.08% at 30 min vs 1.57% at 60 min dose/brain for [125I]IBOX and [125I]TZDM, respectively). In addition, the washout from the brain was much faster for [125I]IBOX as compared to [125I]TZDM. Based on the data presented for [125I]IBOX, it is predicted that the brain trapping of this new radioiodinated ligand in the Abeta containing regions will be more favorable than that of the parent compound, [125I]TZDM. Further evaluation of [125I]IBOX is warranted to confirm the Abeta plaque labeling properties in vivo.

Alzheimer Disease↗
PubMed2001

Electrophysiologic characteristics of ventricular extrastimulation-induced dissipation of functional bundle branch block associated with supraventricular tachycardia.

INTRODUCTION: Linking-related anterograde functional bundle branch block during supraventricular tachycardia (SVT) is due to repetitive concealed retrograde conduction of impulses from the contralateral bundle branch and can be eliminated by a critically timed premature ventricular beat (PVB). We assessed the electrophysiologic characteristics of PVB-induced dissipation of functional bundle branch block during SVT. METHODS AND RESULTS: During SVT with functional bundle branch block, PVB was delivered from the right ventricular apex, scanning the tachycardia cycle length (CL) with 10-msec decrements in the coupling interval in 14 patients (3 AV nodal reentrant tachycardia and 11 orthodromic AV reciprocating tachycardia). Dissipation was achieved in group 1: functional right bundle branch block (RBBB) in 4, functional left bundle branch block (LBBB) in 4, and both functional RBBB and LBBB in 1 with a dissipation zone occupying 4% to 13% (mean 8.5%) of the tachycardia CL. The outer limits were 22+/-16 msec and 68+/-14 msec < tachycardia CL; the inner limits were 56+/-18 msec and 90+/-24 msec < tachycardia CL for RBBB and LBBB, respectively (both P < 0.05). Dissipation could not be achieved in group 2 (4 RBBB and 1 LBBB) due to CL-dependent bundle branch block and/or local ventricular refractoriness. CONCLUSION: During SVT, functional bundle branch block due to "linking" often can be dissipated by timely PVB delivered from the right ventricular apex within a narrow zone of the tachycardia CL. Our findings suggest that the dissipation zone is affected by the pattern of functional bundle branch block relative to the site of PVB delivery.

Adolescent↗
PubMed2001

Key role for sulfur in peptide metabolism and in regulation of three hydrogenases in the hyperthermophilic archaeon Pyrococcus furiosus.

The hyperthermophilic archaeon Pyrococcus furiosus grows optimally at 100 degrees C by the fermentation of peptides and carbohydrates. Growth of the organism was examined in media containing either maltose, peptides (hydrolyzed casein), or both as the carbon source(s), each with and without elemental sulfur (S(0)). Growth rates were highest on media containing peptides and S(0), with or without maltose. Growth did not occur on the peptide medium without S(0). S(0) had no effect on growth rates in the maltose medium in the absence of peptides. Phenylacetate production rates (from phenylalanine fermentation) from cells grown in the peptide medium containing S(0) with or without maltose were the same, suggesting that S(0) is required for peptide utilization. The activities of 14 of 21 enzymes involved in or related to the fermentation pathways of P. furiosus were shown to be regulated under the five different growth conditions studied. The presence of S(0) in the growth media resulted in decreases in specific activities of two cytoplasmic hydrogenases (I and II) and of a membrane-bound hydrogenase, each by an order of magnitude. The primary S(0)-reducing enzyme in this organism and the mechanism of the S(0) dependence of peptide metabolism are not known. This study provides the first evidence for a highly regulated fermentation-based metabolism in P. furiosus and a significant regulatory role for elemental sulfur or its metabolites.

Culture Media↗
PubMed2001

Changing prevalence of hepatitis C virus genotypes: molecular epidemiology and clinical implications in the hepatitis C virus hyperendemic areas and a tertiary referral center in Taiwan.

To determine the hepatitis C virus (HCV) genotype distribution in Taiwan and to clarify the relationship between genotype and the pathogenesis of HCV infection, 1,164 subjects positive for serum HCV antibodies and HCV RNA from three HCV hyperendemic areas (Masago, Tzukuan, and Taoyuan) and a tertiary referral center in Taiwan were studied during 1995-1997. HCV genotypes and viral loads were determined using Okamoto's method and branched DNA assay, respectively. Genotype 1b was the most prevalent in Tzukuan (61.9%), Taoyuan (76.9%), and the referral center (47.0%). By contrast, genotype 2a was the major HCV type in Masago (63.5%). Prevalence of genotype 1b positively and that of genotype 2a negatively correlated to age, regardless of study populations (P < 0.01). Based on multivariate analysis, the significant factors associated with the presence of cirrhosis, with or without hepatocellular carcinoma, in chronic hepatitis C patients were genotype 1b and age. In conclusion, these results underline that independent HCV outbreaks continue in HCV hyperendemic areas in Taiwan, concomitant with a changing relative prevalence of HCV genotypes in relation to age. Both the correlation of genotype 1b with age (cohort effect) and intrinsic properties of HCV genotypes are probably responsible for the association between genotype and the pathogenesis of HCV infection.

Adolescent↗
PubMed2001

Quantification of serotonin transporters in nonhuman primates using [(123)I]ADAM and SPECT.

UNLABELLED: We reported recently a highly selective radioligand, 2-([2-([dimethylamino]methyl)phenyl]thio)-5-[(123)I]iodophenylamine (ADAM), for SPECT imaging of serotonin transporters (SERT). In this article we describe the kinetic modeling of [(123)I]ADAM and its ability to quantitatively and reproducibly measure the concentrations of SERT in the nonhuman primate brain. We also investigate simplified models of tracer behavior that do not require invasive arterial blood sampling. METHODS: Three female baboons each underwent 3 [(123)I]ADAM SPECT studies. The studies consisted of a dynamic sequence of seventy-two 5-min scans after injection of 330 +/- 50 MBq (mean +/- SD) [(123)I]ADAM. Rapid arterial blood samples were obtained and corrected for the presence of labeled metabolites. Dynamic imaging and metabolite-corrected plasma data were analyzed using graphic analysis to give the distribution volumes (DVs) of different brain regions. DV ratios (DVRs) of target to cerebellum were derived and compared against a kinetic reference tissue model and simple target-to-background ratio. RESULTS: Averaged over all 9 scans, the mean DV in the midbrain was 4.86 +/- 1.06 mL/mL and the mean DV in the cerebellum was 2.25 +/- 0.48 mL/mL. The mean test-retest repeatability of the midbrain DV was 14.5%. The reference tissue model gave a mean midbrain DVR of 2.01 +/- 0.17 and correlated strongly with the DVR calculated from the full kinetic model (correlation coefficient [R(2)] = 0.94; P < 0.001), but with much improved repeatability (test-retest, 5.4%; intersubject variability, 5.2%). Similarly, the simple ratio method gave strong correlations with the full kinetic model (R(2) = 0.89; P < 0.001) and a test-retest of 7.6%. CONCLUSION: Accurate, repeatable quantification of SERT in the nonhuman primate brain is possible using kinetic modeling of dynamic [(123)I]ADAM SPECT scans. Simplified models, which do not require arterial blood sampling, gave accurate results that correlated strongly with the full kinetic model. The test-retest reliability of the simplified reference region models was excellent. Quantification of SERT is possible using full kinetic modeling and also with simpler reference region methods.

Animals↗
PubMed2001

Protective effect of human CD40-Ig fusion protein in a murine model of acute graft-versus-host disease.

OBJECTIVE: To investigate the protective effects of blocking CD40/CD40L interactions with human CD40-Ig fusion protein in a murine graft-versus-host disease model. METHODS: Human CD40 gene extracellular region was inserted into plasmid pIG1, which contains genomic human IgG1 Fc gene. A transient vector containing CD40-Fc fusion gene was transfected into COS-7 cells. The CD40-Ig fusion protein was detected through enzyme-linked immunosorbent assay (ELISA). A constitutive vector was also generated by ligating the CD40-Fc fusion gene into pcDNA3.1 and transfecting it into CHO cells. CD40-Ig was purified by protein A affinity chromatography. SDS-PAGE, Western blot and ligand binding assay were used to identify the qualities of CD40-Ig. Murine acute graft-versus-host disease (GVHD) was induced by intravenous injection of C57BL/6J (H-2b) spleen cells into sub-lethally irradiated BALB/c (H-2d) mice. Protective effects against murine graft-versus-host disease by in vivo administration of CD40-Ig were evaluated. RESULTS: Mammalian expression vectors pIG/40Ig and p3.1/40Ig were constructed as described above. Chimeric proteins were expressed in COS-7 and CHO cell culture supernatant and confirmed by ELISA and Western blot. SDS-PAGE showed that fusion proteins had a disulfide-bonded dimeric structure and existed as homodimer. Purified CD40-Ig could bind to CD40L. In vivo administration of CD40-Ig could prevent the development of GVHD and significantly prolong the mean survival time of mice with graft-versus-host disease. CONCLUSIONS: These results demonstrate that CD40/CD40L interactions play an important role in the pathogenesis of graft-versus-host disease and suggest clinical potential for CD40-Ig in the prevention and treatment of human graft-versus-host disease.

Acute Disease↗
PubMed2001

Biological features of mesenchymal stem cells from human bone marrow.

OBJECTIVE: To study the biological characteristics of mesenchymal stem cells (MSCs) from human bone marrow. METHODS: A culture of mesenchymal stem cells was initiated from bone marrow low-density mononuclear cells separated by Percoll Centrifugation and maintained in low-glucose Dulbecco's modified Eagle's medium (DMEM) with 10% selected fetal calf serum. Cell growth pattern and its responses to cytokines were evaluated by trypan blue exclusion and MTT test, respectively. Cell cycle and surface antigenic features were analyzed by flow cytometry technique. Cytochemistry characteristics of MSCs were determined. RESULTS: Easy-handling methods to isolate and culture expand MSCs were developed in this study. MSCs were unique in their phenotypes. They were positive for CD29, CD44, CD166, and negative for CD34, CD45, HLA-DR and Ulex europaeus. Cytochemistry evaluation showed that MSCs were homogeneously positive for acid alpha-naphthl acetate esterase (ANAE), glycogen (periodic acid Schiff reaction, PAS), and negative for acid phosphatase (ACP) and the Sudan black reaction (SB). Around 5% of them were positive for alkaline phosphatase (ALP). The cells had a population doubling time of 30 hours and cell cycle analysis showed that approximately 10% of them were in S phase. MSCs grew at significantly different rates when incubated in the presence of various recombinant human cytokines, of which interferon gamma, tumor necrosis factor alpha, stem cell factor and insulin-like growth factor promoted the proliferation of MSCs dramatically, while others tested had no effects on cell growth. CONCLUSIONS: MSCs are a homogenous population of cells that have unique growth, phenotypical and cytochemical characteristics. Furthermore, the diverse responses of MSCs to different cytokines provide a clue for the selection of optimal expansion and maintenance of MSCs.

Activated-Leukocyte Cell Adhesion Molecule↗
PubMed2001

[Imitative restenosis after percutaneous transluminal coronary angioplasty prevented by buyang huanwu decoction in rabbits].

OBJECTIVE: To examine the preventive effect of Buyang Huanwu Decoction (BYHWD) on imitative restenosis after percutaneous transluminal coronary angioplasty (PTCA) in diet-induced atherosclerotic rabbits. METHODS: Diet-induced atherosclerotic rabbits were randomly allocated into group 1 (n = 24, fed with BYHWD one week before and 4 weeks after the operation, 2 ml/kg per day, containing herbal drug 8.4 g/ml) and group 2 (n = 20, as control). Balloon angioplasty was performed in the abdominal arota to mimic coronary angioplasty. RESULTS: Sixty days after operation: (1) Incidence of hyperplasia of the intima was 7/24 (29.2%) in group 1 vs 17/20 (85.0%) in group 2, P < 0.01; (2) Comparison of area of hyperplastic intima was (0.54 +/- 0.21) mm2 vs (1.67 +/- 0.75) mm2, P < 0.01; (3) Area of hyperplastic intima/area of lumen (limited by the internal elastic membrane was (18.0 +/- 7.2)% vs (56.0 +/- 17.1)%, P < 0.01; (4) Intact lumen/dilated lumen was (0.74 +/- 0.03) vs (0.35 +/- 0.07), P < 0.01; (5) Effect of serum taken from group 1 on cultured smooth muscle cells showed by 3H-TdR method was (4110.14 +/- 1977.01) cpm, which was significantly less than that of serum taken from group 2 [(7960.14 +/- 2802.59) cpm, P < 0.05]. CONCLUSION: BYHWD has significant preventive effect on the imitative post PTCA restenosis in diet-induced atherosclerotic rabbits.

Angioplasty, Balloon, Coronary↗