Biomedical subjects

C H Lin

Publications and source records attributed to C H Lin.

At least 109 records · Page 6Linked to original sources

PubMed2000

Helicobacter pylori culture and antimicrobial susceptibility from pediatric patients in Michigan.

BACKGROUND: We recently observed a high failure rate in the eradication of Helicobacter pylori infection in children with 2-week triple therapy using lansoprazole, amoxicillin and clarithromycin. We performed a prospective evaluation of antral biopsies of all children subsequently diagnosed with H. pylori gastritis for culture and antimicrobial susceptibility assessment. METHODS: All children with antral nodularity and/or an elevated anti-H. pylori IgG titer underwent antral biopsies for histology, urease test and culture while undergoing an upper endoscopy for routine indications. All positive cultures were tested for antimicrobial susceptibility by E-test for clarithromycin, amoxicillin, tetracycline and metronidazole. RESULTS: Thirty-one children (16 male, 15 female) between 2 and 19 years of age were diagnosed with H. pylori gastritis by histology. However, culture was positive in only 22 of 31 (71%) patients. The E-test in vitro antimicrobial susceptibility testing revealed that 95.6% of the isolates were susceptible to amoxicillin, 59% to clarithromycin and 54.6% to metronidazole. There was no resistance to tetracycline. CONCLUSION: Evaluation of antibiotic resistance profiles from pediatric patients from different geographic areas can help in optimizing therapeutic regimen to prevent treatment failures. Metronidazole and clarithromycin resistance is much higher in our pediatric population than reported in adults and could be a major contributor to failure of H. pylori eradication.

Adolescent↗

PubMed2000

Conventional versus endoscopic free gracilis muscle harvest.

Compared with conventional techniques, the endoscopically assisted harvest of free tissue has advantages such as minimal interference with cosmesis and reduced donor-site morbidity. However, the procedure also requires training and has an extensive learning period. In this series of 22 patients, the initial gracilis muscle flaps were harvested using a conventional method; the subsequent flaps were harvested with the aid of endoscopic instrumentation. Endoscopically assisted gracilis muscle harvest in 16 patients was compared with open method harvest in six patients. The endoscopically assisted group had an average incision length of 6.5 cm; that of the conventional group was 15.5 cm. There was one reexploration in the endoscopically assisted group, but all flaps were transferred successfully. Using this minimally invasive technique of vascular and muscular dissection, assisted by endoscopic instruments designed for distal muscle dissection and transection, the gracilis muscles can be harvested within 40 minutes. We consider endoscopically assisted harvest of free gracilis muscle to be safe, relatively simple, and cost-effective.

Adult↗

PubMed2000

Widely split latissimus dorsi muscle flaps for reconstruction of long soft-tissue defects in lower extremities.

Although the latissimus dorsi is one of the largest and longest muscles in the human body, it is still sometimes inadequate for reconstruction of a soft-tissue defect of extensive length and dimension. Eight patients with such lower limb defects were treated with latissimus dorsi muscles split into two hemiflaps sequentially linked, one after the other like a chain. Six transfers were completely successful, one required reexploration for arterial occlusion, and two hemiflaps had a partial loss that could be managed by touching up the skin graft. The average split sequential-link muscle was 42 cm in length. Although two patients had a partial loss, we consider that the widely split single latissimus dorsi muscle can still be used reliably to reconstruct a long slender defect, or two separate, longitudinally located, medium-sized defects in the same leg.

Adult↗

PubMed2000

Subjective memory complaint in relation to cognitive performance and depression: a longitudinal study of a rural Chinese population.

OBJECTIVES: To examine the associations of subjective memory complaint (SMC) in old age with (a) objective test performance, (b) past and subsequent cognitive decline, and (c) depression. DESIGN: A group of community residents were examined twice during a 3-year period. SETTING: Two townships on a rural Chinese islet. PARTICIPANTS: A total of 543 men and women aged 65 years and older. MEASUREMENTS: During each examination, neurologists interviewed and examined all participants for dementia and asked the question, "Do you have trouble with your memory?" In addition, research assistants administered (a) the Cognitive Abilities Screening Instrument (CASI) to assess cognitive abilities, including long-term memory (LTM) and short-term memory (STM), and (b) the Geriatric Depression Scale-Short Version (GDS-S) to assess symptoms of depression. RESULTS: At each examination, almost half of the subjects acknowledged having trouble with their memory (the SMC+ group). At both examinations, the SMC+ group scored significantly lower on the CASI and significantly higher on the GDS-S than the SMC- group. However, the presence of SMC was not associated with faster cognitive decline over the past or subsequent 3 years. There were no consistent associations between SMC and the demographic variables of age, gender, and education at the two examinations. Logistic regression analysis showed that SMC was associated with poorer memory test scores after controlling for gender, age, education, and depression. CONCLUSIONS: SMC was associated with poorer objective memory performance even after controlling the effect of depression and demographic data, but SMC did not predict faster cognitive decline or dementia over 3 years.

Aged↗

PubMed2000

Assembly of a functional beta interferon enhanceosome is dependent on ATF-2-c-jun heterodimer orientation.

Heterodimeric transcription factors, including the basic region-leucine zipper (bZIP) protein ATF-2-c-jun, are well-characterized components of an enhanceosome that mediates virus induction of the human beta interferon (IFN-beta) gene. Here we report that within the IFN-beta enhanceosome the ATF-2-c-jun heterodimer binds in a specific orientation, which is required for assembly of a complex between ATF-2-c-jun and interferon regulatory factor 3 (IRF-3). We demonstrate that correct orientation of the ATF-2-c-jun binding site is required for virus induction of the IFN-beta gene and for IRF-3-dependent activation of a composite ATF-2- c-jun-IRF site in the IFN-beta promoter. We also show that in vitro the DNA-bound ATF-2-c-jun heterodimer adopts a fixed orientation upon the binding of IRF-3 at an adjacent site in the IFN-beta enhancer and that the DNA-binding domain of IRF-3 is sufficient to mediate this effect. In addition, we show that the DNA-binding domain of ATF-2 is necessary and sufficient for selective protein-protein interactions with IRF-3. Strikingly, in vivo chromatin immunoprecipitation experiments with IFN-beta reporter constructs reveal that recruitment of IRF-3 to the IFN-beta promoter upon virus infection is dependent on the orientation of the ATF-2-c-jun heterodimer binding site. These observations demonstrate functional and physical cooperativity between the bZIP and IRF transcription factor families and illustrate the critical role of heterodimeric transcription factors in formation of the IFN-beta enhanceosome.

Activating Transcription Factor 2↗

PubMed2000

Association study of apolipoprotein E epsilon4 with clinical phenotype and clozapine response in schizophrenia.

Schizophrenic patients with the apolipoprotein E (APOE = gene; apoE = protein) epsilon4 allele exhibited lower psychosis scores than patients without the epsilon4 allele in previous reports. The present study tested the hypothesis that the APOE epsilon4 allele confers association with the clinical manifestations of schizophrenia or clozapine response. A total of 95 schizophrenic patients who were treatment resistant were included in the study. The results demonstrated that the presence of the APOE epsilon4 allele did not influence the response to clozapine in schizophrenic patients, neither was the baseline psychopathology related to the APOE epsilon4 allele. Given the multiple functions of the apoE protein in the brain, further study of the influence of APOE on CNS medication response is needed.

Adult↗

PubMed2000

A novel cytotoxic C-methylated biflavone from the stem of Cephalotaxus wilsoniana.

Bioassay-directed fractionation of an ethanolic extract of Cephalotaxus wilsoniana has resulted in the isolation of a novel C-methylated biflavone, taiwanhomoflavone-A (1). Its structure was elucidated on the basis of spectroscopic analysis. Taiwanhomoflavone-A is cytotoxic with ED50 values of 3.4, 1.0, 2.0 and 2.5 microg/ml, respectively, against KB epidermoid carcinoma of nasopharynx, COLO-205 colon carcinoma, Hepa-3B hepatoma, and Hela cervix tumor cells.

Antineoplastic Agents, Phytogenic↗

PubMed2000

Major hematological diseases associated with cleft lip and palate.

OBJECTIVE: Cleft lip and palate is among the most common congenital anomalies. Its association with major blood disorders has rarely been reported. The purpose of this study was to report two patients who had major blood diseases associated with cleft lip and palate. PATIENTS AND RESULTS: From June 1995 to December 1997, there were 2700 patients with cleft lip, cleft palate, or both who received treatment at Chang Gung Memorial Hospital. Two of them were found to have major hematological disorders. In both cases, the disorder was detected by preoperative blood cell counts and white cell differentiation. Case 1 was a 21-year-old woman patient with repaired right cleft lip. She was admitted for alveolar bone grafting and closure of oronasal fistula. Abnormal presentation of blast cells was found, and subsequent bone marrow study confirmed acute lymphocytic leukemia. Case 2 was a 26-year-old man with left secondary cleft lip nasal deformity scheduled to receive staged reconstructive operations. An elevated platelet count was found and subsequently confirmed to represent essential thrombocytosis. In both cases, reconstructive operations for the cleft-related deformities were performed. CONCLUSIONS: Association of major hematological disorders and cleft lip, palate, or both is rare and is reported herein.

Adult↗

PubMed2000

Involvement of protein kinase C-gamma in IL-1beta-induced cyclooxygenase-2 expression in human pulmonary epithelial cells.

The signaling pathway of protein kinase C (PKC) is known to play a role in mediating the action of various cytokines. Here we examined the signal transduction pathway of PKC activation and the role of PKC isoforms in interleukin-1beta (IL-1beta)-mediated cyclooxygenase-2 (COX-2) expression in human pulmonary epithelial cell line (A549). The tyrosine kinase inhibitors (genistein and tyrphostin AG126) and phosphatidylcholine-phospholipase C inhibitor (D-609) prevented IL-1beta-induced prostaglandin E(2) (PGE(2)) release and COX-2 expression, whereas U-73122 (a phosphatidylinositol-phospholipase C inhibitor) and propranolol (a phosphatidate phosphohydrolase inhibitor) had no effect. The PKC inhibitors (Go 6976 and Ro 31-8220) and NF-kappaB inhibitor, pyrrolidine dithiocarbamate, also attenuated IL-1beta-induced PGE(2) release and COX-2 expression. Western blot analysis using PKC isoenzyme-specific antibodies indicated that A549 cells expressed PKC-alpha, -gamma, -iota, -lambda, -zeta, and -micro. IL-1beta caused the translocation of PKC-gamma but not other isoforms from cytosol to the membrane fraction. Moreover, the translocation of PKC-gamma was inhibited by genistein or D-609, but not by U-73122. IL-1beta caused the translocation of p65 NF-kappaB from cytosol to the nucleus as well as the degradation of IkappaB-alpha in cytosol. Furthermore, the translocation of p65 NF-kappaB was inhibited by genistein, Go 6976, Ro 31-8220, or pyrrolidine dithiocarbamate. These results indicate that in human pulmonary epithelial cells, IL-1beta might activate phosphatidylcholine-phospholipase C through an upstream tyrosine phosphorylation to elicit PKC activation, which in turn initiates NF-kappaB activation, and finally induces COX-2 expression and PGE(2) release. Of the PKC isoforms present in A549 cells, only activation of PKC-gamma is involved in regulating IL-1beta-induced responses.

Cyclooxygenase 2↗

PubMed2000

Distribution of CAG repeat size in the dentatorubral and pallidoluysian atrophy (DRPLA) gene in a normal population in Taiwan.

Dentatorubral and pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder with expansion of trinucleotide CAG repeats in the coding region of the gene. Expansion of the repeat tract beyond the normal range produces gene products with extended polyglutamine tracts. In this study, we analyzed the distribution of the CAG repeats in the DRPLA alleles in a normal Taiwanese population. We observed 15 different alleles and found that the range of the CAG repeat number was from 7-21. The most frequent allele contained 15 CAG repeats that represented 20% of the total analyzed alleles, followed by the 17 repeats (15.8%). The heterozygosity rate of this locus was 88%. Twelve parents-to-children transmissions of the DRPLA alleles in a Machado-Joseph disease family appeared to be normal without any alteration of the CAG repeat numbers. Phenotypes of DRPLA overlapped those of autosomal dominant cerebellar ataxia (ADCA). In order to identify DRPLA patients in Taiwan, we screened six autosomal dominant cerebellar ataxia patients without expansion in known spinocerebellar ataxia genes. All six patients had the repeat numbers within the normal range; thus, the possibility of DRPLA could be excluded.

Alleles↗

PubMed2000

Mechanisms involved in the antiplatelet activity of Staphylococcus aureus lipoteichoic acid in human platelets.

In this study, gram-positive Staphylococcus aureus lipoteichoic acid (LTA) dose-dependently (0.1-1.0 microg/ml) and time-dependently (10-60 min) inhibited platelet aggregation in human platelets stimulated by agonists. LTA also dose-dependently inhibited phosphoinositide breakdown and intracellular Ca+2 mobilization in human platelets stimulated by collagen. LTA (0.5 and 1.0 microg/ml) also significantly inhibited thromboxane A2 formation stimulated by collagen in human platelets. Moreover, LTA (0.1-1.0 microg/ml) dose-dependently decreased the fluorescence of platelet membranes tagged with diphenylhexatrience. Rapid phosphorylation of a platelet protein of Mr. 47,000 (P47), a marker of protein kinase C activation, was triggered by PDBu (30 nM). This phosphorylation was markedly inhibited by LTA (0.5 and 1.0 microg/ml) within a 10-min incubation period. These results indicate that the antiplatelet activity of LTA may be involved in the following pathways: LTA's effects may initially be due to induction of conformational changes in the platelet membrane, leading to a change in the activity of phospholipase C, and subsequent inhibition of phosphoinositide breakdown and thromboxane A2 formation, thereby leading to inhibition of both intracellular Ca+2 mobilization and phosphorylation of P47 protein. Therefore, LTA-mediated alteration of platelet function may contribute to bleeding diathesis in gram-positive septicemic and endotoxemic patients.

Calcium Signaling↗

PubMed2000

Fatal anaphylactoid shock associated with protamine for heparin reversal during anesthesia.

A 19-year-old female was scheduled for elective surgery of repair of ventricular septal defect (VSD). She had no known previous food or drug allergy history. She was not previously exposed to protamine and did not have any of the risk factors pointing to protamine hypersensitivity reaction. Unfortunately there were two anaphylactoid shocks occurring during this surgery. One was caused by intravenous (i.v.) administration of antibiotics, and the other happened following i.v. drip of protamine sulfate for reversal of systemic heparinization. She had none of the risk factors suggestive of hypersensitivity to drugs and was therefore considered not at risk for such severe adverse reactions which happened. This article was to discuss the anaphylactoid shock induced by antibiotics and protamine during anesthesia, and the prevention and management of such a reaction.

Adult↗

PubMed2000

Diverticulosis of the appendix with diverticulitis: case report.

Diverticulum of the appendix is rarely encountered. A case of appendiceal diverticulosis is described. A 46-year-old male patient was sent to our hospital with presentation of acute appendicitis-like symptoms. The appendix was removed by laparoscopic appendectomy, and it showed erythematous change with local peritoneal reaction and omental shift at the tip. Pathological examination revealed three diverticula in the appendix. One of them was inflamed but the appendix itself was not. All three diverticula were pseudodiverticula, lacking muscularis propria. The appendix in this case showed only focal inflammatory change, which differs from what occurs in acute appendicitis, where diffuse inflammation of the appendix is usually noted. In cases of an appendix with only focal erythematous change, minor lesions such as diverticulitis may be revealed by pathological examination, and an appendectomy is still warranted. Diverticulitis of the appendix cannot be differentiated from acute appendicitis preoperatively. Image studies including abdominal computed tomography scan, ultrasonography, and plain film cannot improve the diagnosis. To our knowledge, diverticulosis of the appendix has never been reported in Taiwan.

Appendicitis↗

PubMed2000

The consistency and reliability of periodontal bone level measurements using digital scanning radiographic image analysis--a pilot study.

The purpose of the present study was to evaluate the consistency and reliability of alveolar bone height measurement using digital scanning radiographic image analysis (DSRIA). A randomly selected (standardized paralleling technique) periapical radiographs of 20 molar teeth (10 maxillary molars and 10 mandibular molars) from 178 individuals with periodontitis were reporting or referred to the patient population of the dental clinics of the teaching hospital. Radiographic measurements were performed and read by two examiners, with a separation time of three weeks of different tooth groups and as established by double reading of 20 molar teeth in 10 individuals using the DSRIA. The calculating data of radiographic alveolar bone loss (RABL) measured and analyzed by the DSRIA for each molar group were compared based on the inter- and intra-examiners' data. The means and standard deviations were calculated to compare radiographs of the inter- and intra-examiners' groups. The reliability coefficients were computed to assess the consistency and reliability for each molar group. The results revealed that the intra- and inter-examiners' reliability coefficients ranged from 0.986 to 0.995 (p < 0.001, significantly different from 0). An excellent reproducibility was indicated in maxillary molar, mandibular molar and of both arches, respectively. It was concluded that the standard periapical radiograph using the DSRIA has the potential to be a valuable and reliable method in measuring linear alveolar bone defects caused by periodontitis.

Adult↗

PubMed1999

On-line identification of diastereomeric dibenzo[a,l]pyrene diol epoxide-derived deoxyadenosine adducts by capillary electrophoresis-fluorescence line-narrowing and non-line narrowing spectroscopy.

A capillary electrophoretic method for the separation and on-line identification of closely related analytes using low-temperature fluorescence spectroscopy is reported for the eight diastereomeric deoxyadenosine (dA) adducts derived from dibenzo[a,l]pyrene diol epoxide (DB[a,l]PDE). Electrophoretic separation of stereoisomers was accomplished by application of a mixed surfactant buffer [dioctyl sulfosuccinate (DOSS) and Brij-S], which was below the critical micelle concentration (CMC) due to the high concentration (approximately 25%) of organic solvent. Addition of multiple surfactant additives to the separation buffer provided electrophoretic resolution, which was unattainable under single surfactant conditions. It is shown that the CE-separated analyte zones could be identified on-line via low-temperature (4.2 K) fluorescence non-line narrowing and fluorescence line-narrowing (FLN) spectroscopy. In addition, it was determined that in CE buffer trans-syn-,cis-syn- and cis-anti-DB[a,l]PDE-14-N6dA diastereomeric adducts exist mostly with the -dA and DB[a,l]P moiety in an "open"-type conformation while the trans-anti-DB[a,l]PDE-14-N6dA adducts exist in two different conformations whose relative distribution depends on matrix composition. The above conformations have also been revealed by selective laser excitation. Thus, the low-temperature methodology not only provides fingerprint structure via vibrationally resolved 4.2 K fluorescence spectra for adduct identification, but also provides conformational information on the spatial relationship of the carcinogen and dA moiety. These results, taken together with those for DB[a,l]P-DNA adducts formed in standard glasses and mouse epidermis exposed to DB[a,l]P, support our earlier findings that DB[a,l]P-derived adducts exist in different conformations [Jankowiak et al., Chem. Res. Toxicol. 11 (1998) 674]. Therefore, the combination of the separation power of CE and spectral selectivity of low-temperature fluorescence spectroscopy at NLN and FLN conditions provides a powerful methodology which should prove useful for identification of closely related DNA adducts formed at low levels in biological systems.

Benzopyrenes↗

PubMed1999

Recombinant rhodostomin substrates induce transformation and active calcium oscillation in human platelets.

Platelet activation has been a focus of numerous studies in normal and abnormal states. Morphological changes and calcium signals found with activated platelets in vitro have been well characterized. However, the rate of cell spreading on substrates and the frequency of calcium oscillation within individual platelets upon activation have not yet been reported. In this study, we first examined the ability of a recombinant fusion protein of rhodostomin (GST-rhodostomin), a snake disintegrin containing an Arg-Gly-Asp (RGD) motif, to activate platelets when GST-rhodostomin served as a substrate. Four aspects of platelet activities induced by immobilized GST-rhodostomin and fibrinogen were analyzed in parallel. Examinations of (1) translocation of P-selectin from intracellular compartments to the plasma membrane, (2) platelet adhesion to and spreading on substrates, (3) platelet contact pattern on substrates, and (4) the degree of phosphorylation of focal adhesion kinase in platelets indicated that GST-rhodostomin was a better substrate for platelet activation than fibrinogen. Analysis of the rate of platelet spreading on GST-rhodostomin was examined by time-lapsed video microscopy. The spreading rate averaged 0.43 micrometer/minute, while cell spreading averaged 0.22 micrometer/minute when platelets were plated on fibrinogen and treated with thrombin. A newly developed method, using time-lapsed microscopy and the Metamorph program, was used to analyze calcium signals within platelets. We found that platelets on GST-rhodostomin evoked calcium oscillation at a frequency of 4.77 spike/cell/minute vs 2.76 spike/cell/minute on fibrinogen. The results of cell spreading and calcium oscillation were consistent with the results of microscopic and biochemical assays. We therefore conclude that the determination of the rate of platelet spreading and the frequency of calcium oscillation within platelets performed in this study provides more quantitative parameters for measuring platelet activities. Our results also suggest that GST-rhodostomin might potentially be used as a probe to dissect the molecular mechanisms underlying the kinetic processes of platelet activation.

Actins↗

PubMed1999

Reduction in lipopolysaccharide-induced thrombocytopenia by triflavin in a rat model of septicemia.

BACKGROUND: Thrombocytopenia frequently occurs early in the course of Gram-negative bacterial infections. Triflavin, an Arg-Gly-Asp-containing disintegrin, has been suggested to interfere with the interaction of fibrinogen with the glycoprotein IIb/IIIa complex. The present study was undertaken to determine whether triflavin could prevent thrombocytopenia in lipopolysaccharide (LPS)-treated rats. METHODS AND RESULTS: In this study, 51Cr-labeled platelets were used to assess blood and tissue platelet accumulation after LPS challenge. The administration of LPS (4 mg/kg IV bolus) for 4 hours induced a reduction in radiolabeled platelets in blood and an obvious accumulation of platelets in liver. Triflavin (500 microg/kg) but not GRGDS (20 mg/kg) significantly prevented the alteration of radiolabeled platelet distribution in blood and liver when induced by LPS. Furthermore, triflavin but not GRGDS markedly suppressed the elevation in plasma thromboxane B2 concentration within the 4-hour period of LPS administration. In LPS-treated rats, the 5-hydroxytryptamine level was lower in the blood and higher in the liver compared with levels in normal saline-treated rats. Pretreatment with triflavin (500 microg/kg) significantly reversed the 5-hydroxytryptamine concentration in blood and liver of LPS-treated rats. In histological examinations and platelet adhesion assay, triflavin markedly inhibited the adhesion of platelets to subendothelial matrixes in vivo and in vitro. CONCLUSIONS: The results indicate that triflavin effectively prevents thrombocytopenia, possibly through the following 2 mechanisms: (1) Triflavin markedly inhibits platelet aggregation, resulting in decreased thromboxane A2 formation. (2) It inhibits the adhesion of platelets to subendothelial matrixes, thereby leading to a reversal in the distribution of platelets in blood and liver in LPS-treated rats.

Animals↗

PubMed1999

Serotonin-6 receptor variant (C267T) and clinical response to clozapine.

Clozapine is an effective atypical antipsychotic that has high affinity for serotonin type 6 receptors (5HT6). We tested the hypothesis that clinical response to clozapine in patients refractory to typical antipsychotic treatment is related to the genetic variant (C267T) of the 5HT6 receptors. Ninety-nine schizophrenic patients with a history of non-response to typical antipsychotics were included in the study. The results demonstrated a modest but significant relationship between presence of the variant of the 5HT6 receptors and the response to clozapine in these patients. Patients with homogenous 267T/T genotype had a better response than other patients. Although replication is required, these results suggest that the 5HT6 receptor C267T polymorphism may be involved in clozapine response, especially in patients with anxious or depressed symptoms.

Antipsychotic Agents↗