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Biomedical subjects

Ming-Chih Chou

Publications and source records attributed to Ming-Chih Chou.

11 recordsLinked to original sources
PubMed2004

Expression changes of gelatinases in human osteoarthritic knees and arthroscopic debridement.

PURPOSE: The purpose of this study was to quantify the expression changes of gelatinase-A and -B (matrix metalloproteinase [MMP]-2 and MMP-9) in a series of chondral, meniscal, and synovial cultures of knee osteoarthritis (OA) for investigation of the possible roles of the cartilage, menisci, and synovia and the efficacy of arthroscopic debridement. TYPE OF STUDY: A biochemical study. METHODS: In 43 consecutive patients with knee OA undergoing arthroscopic debridement, we examined the amount of MMP-2 and MMP-9 in a series of chondral, meniscal, and synovial cultures. We also compared the gene expressions of MMP-2 and MMP-9 and membrane-type 1 MMP (MT1-MMP) in the chondral, meniscal, and synovial cultures using reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Latent and activated forms of MMP-2 were produced in all series of chondral, meniscal, and synovial cultures, and the levels in lesional cultures were significantly higher than those in paralesional ones (P <.001). Moreover, the latent form of MMP-9 (proMMP-9) appeared in 29 of 37 series of synovial cultures and in 13 of 40 series of meniscal cultures. In meniscal cultures after 24 hours of incubation and synovial cultures after 3 and 24 hours of incubation, the level of proMMP-9 in lesional cultures was significantly higher than that in paralesional ones (P <.001). The activated form of MMP-9 appeared in 10 of 37 series of synovial cultures, and the level in lesional cultures was significantly higher than that in paralesional ones (P <.05). Furthermore, MMP-2, -9, and MT1-MMP mRNA levels of lesional areas also showed the increased expression in RT-PCR. CONCLUSIONS: Our data confirm that tissue repair of OA is ascribable to enzymic digestion of the extracellular matrix ex vivo. When technically appropriate, arthroscopic debridement for the pathologic lesions of OA, such as meniscal tears, chondral lesions, and hypertrophic villi, may be beneficial to the process of early cases. Still, it should be carefully studied for its overall effect and mechanism in vivo. CLINICAL RELEVANCE: The effectiveness of arthroscopic debridement for the treatment of knee OA is controversial. The present study provides the possible mechanism of the positive effects of arthroscopic debridement in basic science.

Aged↗
PubMed2004

Expression spectra of matrix metalloproteinases in metastatic non-small cell lung cancer.

By combining suppression subtractive hybridization and microarray to examine gene expressions between metastatic and non-metastatic non-small cell lung cancer (NSCLC), we have identified differential expression spectra of matrix metalloproteinases (MMP). Among MMPs, expressions of MMP-13, -14, -15 and -24 decreased, those of MMP-9, -11, -12, -16, -17, -19 and -23B did not change, and those of MMP-1, -2, -7, -8 and -10 increased dramatically. Overexpressions of MMP-1, -2, -7 and -10 were confirmed by reverse transcription-polymerase chain reaction. In this study we further assessed the clinical significance of MMP-1, -2, -7 and -10. Specimens from 472 patients with completely resected NSCLC were examined by immunohistochemistry. The median follow-up period was 38 months (range, 2-113 months). Overexpression of MMP-1 was observed in 72.9% (n=344) of 472 patients, that of MMP-2 was 77.9% (n=352), MMP-7 63.3% (n=299) and that of MMP-10 was 27.1% (n=128). For patients with lymph node metastasis, MMP-1 and -2 overexpressions were not only independent prognostic factors for unfavorable outcome, but also associated with decreased survival (p=0.0015, and p=0.011 respectively). The present study showed that MMP expression spectrum in NSCLC was heterogeneous: expression of some MMP increased, some unchanged, while some decreased. Therefore, it should be worth determining MMP expression pattern as a regimen reference for NSCLC patients who were scheduled to receive MMP inhibitor, which was class-specific, as adjuvant therapeutic agent.

Adult↗
PubMed2003

The significance of altered gelatinase expression in the synovium of patient with arthritic effusions.

In this study we quantified the levels of matrix metalloproteinase-2 and 9 (MMP-2 and 9) in effusions and serial synovial cultures of patients with arthritis of the knee in order to investigate the correlations between MMP and cell counts in effusions as well as the possible roles of the synovium. In 49 patients with arthritis of the knee (series I) we examined the cell counts and the amounts of MMP-2 and 9 in 51 effusions. In 20 knee samples of series I of patients who received arthroscopy (series II), we examined the amounts of MMP-2 and 9 in effusions and serial synovial organ cultures. We also compared the gene expressions of MMP-2 and 9 and MT1-MMP in serial synovial cultures using RT-PCR. In series I, significantly more proMMP-9 appeared in effusions from the inflammatory group than in the non-inflammatory and hemorrhagic group ( p <0.001). The levels of proMMP-9 correlated with the neutrophil counts in the effusions ( p <0.001). In series II synovial cultures, the activities of latent and activated forms of MMP-2 and 9 in lesional areas were all higher than that in paralesional ones ( p <0.05). In RT-PCR analysis, MMP-2, -9 and membrane type 1 MMP mRNA levels of lesional areas also showed increased expression. Our data suggest that the analysis of MMP-9 indicates the inflammatory condition of the joints and that additional synovectomy may be beneficial for patients with inflammatory synovitis, compared with non-inflammatory and hemorrhagic arthritis.

Aged↗
PubMed2003

The correlation between aberrant connexin 43 mRNA expression induced by promoter methylation and nodal micrometastasis in non-small cell lung cancer.

Reduced connexin (Cx) 43 gene expression has been shown in most of lung tumors and cancer cell lines. Although aberrant Cx43 gene expression was linked with lung tumorigenesis, our understanding to the mechanism was still limited. We hypothesized that the evidence of aberrant Cx43 gene expression was gradually intensified from adjacent normal lung tissues surrounding tumors toward tumor tissues. In this study, 90 lung tumors and adjacent normal tissues were collected to examine Cx43 mRNA expression by reverse transcription-PCR (RT-PCR). Our data showed that Cx43 mRNA expression in adjacent normal lung tissue was significantly correlated with nodal involvement (P = 0.03), but the similar trend was not observed in tumor tissues. To verify whether lack of Cx43 mRNA expression resulted from promoter methylation, PCR-based methylation assay was performed for Cx43 promoter methylation analysis. A higher frequency of promoter methylation was observed in Cx43 mRNA-negative patients (21 of 33, 63.7%) compared with Cx43 mRNA-positive patients (3 of 57, 5.3%, P < 0.0001). To elucidate whether aberrant Cx43 gene expression originated from adjacent normal lung tissues, 25 lung tumors and each of five adjacent normal tissues at various distances from tumor tissues were collected to examine Cx43 mRNA and protein expression by RT-PCR and Western blot, respectively. The results show that Cx43 mRNA and protein expressions gradually decreased from adjacent normal lung tissues to tumor tissues with a positive correlation to the distance from the tumor tissues. Gel-shift assay data also revealed that shifted band binding with AP1 was only observed in adjacent normal tissues, which were far from the tumor tissues. These results indicate that promoter methylation may interfere with AP1 binding to the promoter to cause aberrant Cx43 gene expression. Thus, Cx43 mRNA in adjacent normal tissue surrounding lung tumor simply detected by RT-PCR may act as a molecular marker of nodal micrometastasis in non-small cell lung cancer.

Adenocarcinoma↗
PubMed2002

High-frequency death certifiers in Taiwan: a sociocultural product.

Accurate death certification is essential to high-quality mortality statistics. Physicians who certify disproportionately large numbers of deaths can significantly affect the validity of the resultant mortality data. In Taiwan in 1994, 110 death certifiers issued more than 100 death certificates each; and nine of these high-frequency certifiers issued more than 500 death certificates. We explore the cultural, political, economic, historical, and social contexts of high-frequency death certification in Taiwan. Because of the traditional belief in Taiwan that one must die at home for the soul to be incorporated into the collective ancestral tablet of the household, many families bring their loved ones home from the hospital just before death. Hospital physicians cannot legally issue a death certificate in these cases because they did not witness the dying process. Although the government introduced an administrative certification system to handle these outside-hospital deaths, the great demands of this system have attracted many 'special exam' doctors (doctors with no formal medical degree) to adopt death certification as a full-time business. In this context, it is not surprising that 'routinization' of death certification (J. Health Soc. Behav. 32 (1991) 273) has led to low-quality reporting among these certifiers. We argue that attempts to improve the quality of mortality statistics should take into account the unique sociocultural contexts of different countries.

Attitude to Death↗
PubMed2002

Study of an outbreak of Enterobacter cloacae sepsis in a neonatal intensive care unit: the application of epidemiologic chromosome profiling by pulsed-field gel electrophoresis.

OBJECTIVE: From October 1996 to March 1997, a cluster of 11 cases of neonatal sepsis caused by Enterobacter cloacae with similar antimicrobial susceptibility patterns occurred in a neonatal intensive care unit. This outbreak prompted an investigation. METHOD: Twelve isolates obtained from 6 neonatal patients who developed E cloacae sepsis during the outbreak were analyzed. Four E cloacae isolates from 2 preterm neonates without E cloacae infection on the same ward, and 1 isolate from the hands of a nurse, were also examined. No E cloacae were isolated from the environment. Bacterial DNA digested with XbaI or NotI was analyzed with pulsed-field gel electrophoresis. RESULT: Three distinct banding patterns were identified by pulsed-field gel electrophoresis. Of the 6 preterm infants with sepsis, strain I was identified in 1, strain II in 2, a mixed infection of strains I and II in 2, and strain III was found in only 1 infant. An isolate from the hands of a nurse was identified as strain II, as were the 4 isolates from the 2 preterm neonates without E cloacae infection. Thus, this outbreak of sepsis was caused by 2 genotypes of E cloacae. CONCLUSION: This study demonstrates that pulsed-field gel electrophoresis with restriction enzyme digestion is a valuable tool for genetic characterization of multidrug-resistant E cloacae strains during outbreaks.

Bacterial Typing Techniques↗
PubMed2002

Uniportal endoscopic thoracic sympathectomy for treatment of palmar and axillary hyperhidrosis: analysis of 2000 cases.

OBJECTIVE: Primary hyperhidrosis of the upper limbs is a common and troublesome condition in Taiwan. Therefore, we present our experience in treating hyperhidrosis via uniportal endoscopic thoracic sympathectomy. METHODS: Between April 1993 and March 2000, a total of 2000 patients underwent endoscopic thoracic sympathectomy for treatment of palmar or axillary hyperhidrosis. There were 1520 patients with palmar hyperhidrosis and 480 patients with axillary hyperhidrosis. There were 788 male and 1212 female patients, with a mean age of 22.9 years (range, 9-60 yr). All patients were placed in a semi-sitting position, with single-lumen-intubation anesthesia. We performed T2 sympathectomy at the second and third rib beds for patients with palmar hyperhidrosis, using an 8-mm, 0-degree, offset thoracoscope (Karl Storz GmbH & Co., Tuttlingen, Germany), via a 0.8-cm incision below each axilla. Similar procedures were used for T3 and T4 sympathectomies at the third, fourth, and fifth rib beds for patients with axillary hyperhidrosis. Questionnaires were sent to all patients after surgery. RESULTS: Among these 2000 patients, successful bilateral sympathectomies were performed for 1992 patients. The operations were usually completed within 20 minutes (range, 10-30 min). Most patients were discharged within 4 hours after surgery. The surgical complications were minimal, including pneumothorax (10 cases, 0.5%), segmental atelectasis (7 cases, 0.35%), hemothorax (2 cases, 0.1%), and mild wound infections (2 cases, 0.1%). There were no surgery-related deaths. The mean postoperative follow-up period was 51.7 months (range, 6-89 mo). A total of 1720 patients (86%) developed compensatory sweating of the trunk and lower limbs. The recurrence rates for palmar and axillary hyperhidrosis after surgery were 0 and 4.1% in the first year, 0.1 and 8.2% in the second year, 0.5 and 10.4% in the third year, 0.6 and 14.1% in the fourth year, and 1.3 and 16.7% in the fifth year, respectively. CONCLUSION: Uniportal endoscopic thoracic sympathectomy is a safe, effective method for the treatment of patients with palmar or axillary hyperhidrosis. For surgery, both a semi-sitting position and single-lumen-intubation anesthesia are recommended.

Adolescent↗
PubMedDate not supplied

Spinal cord compression caused by extradural arachnoid cysts. Clinical examples and review.

Most spinal arachnoid cysts are asymptomatic and detected incidentally during magnetic resonance imaging or myelography. The etiology of intraspinal arachnoid cyst is not yet clear. We present two children with three spinal extradural arachnoid cysts and each cyst protruded from a separate dura defect. In both patients, plain radiographs demonstrated widening of the interpedicular distance, which suggested progressive widening of the spinal bony canal. Limited laminectomy was performed to remove the intraspinal cysts. Separate dura defects, the apparent predisposing factors, were also found and repaired. The patients completely recovered neurologically. Radical cyst removal and dura defect closure are the surgical intervention of choice in patients with symptomatic extradural arachnoid cyst.

Adolescent↗
PubMedDate not supplied

Paclitaxel affects the amounts of the N-acetylation of 2-aminofluorene and DNA-2-aminofluorene adduct formation in Sprague-Dawley rats.

BACKGROUND: The effects of paclitaxel on the in vivo distribution and the levels of N-acetylation of 2-aminofluorene (AF) and AF-DNA adducts in Sprague-Dawley (SD) rats were studied. METHODS AND RESULTS: For in vivo examination, pretreatment with paclitaxel (50 mg/kg) 48 hours prior to the administration of AF (50 mg/kg) resulted in a 28% and 43% decrease, respectively, in the urinary and fecal recovery of N-acetyl-2-aminofluorene (AAF), and a 22% decrease in the metabolic clearance of AF to AAF. Paclitaxel did not affect the Michaelis-Menten parameters for N-acetyltransferase (NAT) activity in blood, liver, lung, colon and bladder. Similarly, the Km value for AF in the examined tissues was not affected by paclitaxel. However, the Vmax value estimate of liver NAT activity was significantly decreased after paclitaxel pretreatment. Following exposure of rats to AF with and without pretreatment with paclitaxel, DNA-AF adducts were examined in the target tissues, liver, colon and bladder, and also in non-target tissues, lung and circulating leukocytes. The DNA-AF adducts in the liver, bladder, lung, colon and leukocytes were decreased by pretreatment with paclitaxel. CONCLUSION: This is the first finding to show that paclitaxel affects AF distribution and N-acetylation and DNA adduct in SD rats in vivo.

Acetylation↗
PubMedDate not supplied

PCR and flow cytometric analysis of paclitaxel-inhibited arylamine N-acetyltransferase activity and gene expression in human osteogenic sarcoma cells (U-2 OS).

Human epidemiological studies suggest an association between N-acetyltransferase (NAT) activity and the incidence of bladder and colorectal cancers. In this study, paclitaxel was selected to examine the inhibition of arylamine NAT activity, gene expression and 2-aminofluorene-DNA adduct formation in a human osteogenic sarcoma cell line (U-2 OS). The activity of NAT was determined by high performance liquid chromatography (HPLC) assay for the amounts of acetylated 2-aminofluorene (AF) and p-aminobenzoic acid (PABA) and nonacetylated AF and PABA. Human osteogenic sarcoma cell cytosols and intact cells were used to examine the NAT activity, gene expression and AF-DNA adduct formation. The results demonstrated that NAT activity percent of NAT in examined cells, gene expression (NAT1 mRNA) and AF-DNA adduct formation in human osteogenic sarcoma cells were inhibited and decreased by paclitaxel in a dose-dependent manner. The results also demonstrated that paclitaxel decreased the apparent values of Km and Vmax from intact human osteogenic sarcoma cells (U-2 OS). Thus, paclitaxel is an uncompetitive inhibitor of the NAT enzyme.

2-Acetylaminofluorene↗