Biomedical subjects

Ching-Hwa Yang

Publications and source records attributed to Ching-Hwa Yang.

8 recordsLinked to original sources

PubMed2006

Protective effects of eugenol against oxidized LDL-induced cytotoxicity and adhesion molecule expression in endothelial cells.

Eugenol, a natural constituent of a number of aromatic plants and their essential oil fractions, has several biological effects. However, its protective effects against endothelial injury remain unclarified. This study investigates how eugenol affects human umbilical vein endothelial cells (HUVECs) dysfunction mediated by oxidized low density lipoprotein (oxLDL). Our results showed that the suppression of endothelial NO synthase (eNOS) expression, enhancement of adhesion molecules (ICAM, VCAM, and E-selectin) expression, and adherence of monocytic THP1 cells caused by a non-cytotoxic concentration (100 microg/ml) of oxLDL were ameliorated following a eugenol treatment (12.5-100 microM) in HUVECs. Eugneol also inhibited the reactive oxygen species (ROS) generation, intracellular calcium accumulation, and the subsequent mitochondrial membrane potential collapse, cytochrome c release and caspase-3 activation induced by oxLDL. The cytotoxicity and apoptotic features induced by a cytotoxic concentration (200 microg/ml) of oxLDL was also attenuated by eugenol. Our results suggest that eugenol may protect against the oxLDL-induced dysfunction in endothelial cells.

Antioxidants↗

PubMed2006

Protective effects of honokiol against oxidized LDL-induced cytotoxicity and adhesion molecule expression in endothelial cells.

Honokiol, a compound extracted from Chinese medicinal herb Magnolia officinalis, has several biological effects. However, its protective effects against endothelial injury remain unclarified. In this study, we examined whether honokiol prevented oxidized low-density lipoprotein (oxLDL)-induced vascular endothelial dysfunction. Incubation of oxLDL with honokiol (2.5-20 microM) inhibited copper-induced oxidative modification as demonstrated by diene formation, thiobarbituric acid reactive substances (TBARS) assay and electrophoretic mobility assay. Expression of adhesion molecules (ICAM, VCAM and E-selectin) and endothelial NO synthase (eNOS) affected by oxLDL was investigated by flow cytometry and Western blot. We also measured the production of reactive oxygen species (ROS) using the fluorescent probe 2',7'-dichlorofluorescein acetoxymethyl ester (DCF-AM). Furthermore, several apoptotic phenomena including increased cytosolic calcium, alteration of mitochondrial membrane potential, cytochrome c release and activation of caspase-3 were also investigated. Apoptotic cell death was characterized by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) stain. The results showed that honokiol prevented the copper-induced oxidative modification of LDL. Honokiol also ameliorated the oxLDL-diminished eNOS protein expression and reduced the oxLDL-induced adhesion molecules and the adherence of THP-1 cells to HUVECs. Furthermore, honokiol attenuated the oxLDL-induced cytotoxicity, apoptotic features, ROS generation, intracellular calcium accumulation and the subsequent mitochondrial membrane potential collapse, cytochrome c release and activation of caspase-3. Our results suggest that honokiol may have clinical implications in the prevention of atherosclerotic vascular disease.

Antioxidants↗

PubMed2006

Percutaneous nephroscopic resection of renal pelvic fibroepithelial polyp.

Benign fibroepithelial polyps of the renal pelvis are extremely rare, and are frequently mistaken for transitional cell carcinoma. Diagnosis is usually made following nephrectomy or nephroureterectomy for an assumed malignancy of the renal pelvis. We report a 56-year-old female with a right renal pelvic fibroepithelial polyp successfully treated by percutaneous nephroscopic resection.

Endoscopy↗

PubMed2005

Rosiglitazone inhibits endothelial proliferation and angiogenesis.

Rosiglitazone, an insulin sensitizer, is known to offer beneficial effects in retarding atherosclerotic vascular diseases. Since proliferation and angiogenesis are involved in initiation and plaque instability, two critical steps in the cardiovascular events, this study was designed to evaluate the mechanisms of rosiglitazone on endothelial proliferation and angiogenesis. Rosiglitazone-treated human umbilical vein endothelial cells were analyzed for growth rate by use of cell number counting, 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay as well as 3H-thymidine incorporation. Cell cycle analysis was detected by flow cytometry and cell cycle-related proteins were measured by Western blot. Effects of rosiglitazone on angiogenesis were assessed by vascular endothelial growth factor (VEGF)-induced tube formation and wound-healing migration. Furthermore, effects of rosiglitazone on actin stress fiber were observed under confocal microscopy. Our data showed that rosiglitazone inhibits endothelial proliferation in a dose-dependent manner. Rosiglitazone caused endothelial arrest at G1 phase via affecting several cell cycle-related proteins that led to attenuate phosphorylation of retinoblastoma protein. Rosiglitazone markedly decreased VEGF-induced tube formation and endothelial cell migration, which might be explained by a disorganization of the actin cytoskeleton. Our data suggest that both anti-proliferative and anti-angiogenic activities in endothelial cells might account for the greater than expected beneficial effects of rosiglitazone for the treatment and prevention of atherosclerosis.

Cell Division↗

PubMed2005

Resveratrol, a polyphenolic compound in red wine, protects against oxidized LDL-induced cytotoxicity in endothelial cells.

BACKGROUND: Resveratrol, a polyphenolic constituent of red wine, has antioxidant effects. However, its protective effects against oxLDL-induced endothelial injury remained unclarified. METHODS: Primary human umbilical vein endothelial cell cultures (HUVECs) treated with oxLDL (200 microg/ml) were used to explore the protective effect of resveratrol. Cytotoxicity of oxLDL on HUVECs was studied by measuring lactate dehydrogenase (LDH) release, methylthiazol tetrazolium (MTT) and apoptotic cell death as characterized by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) stain. We also measured the production of reactive oxygen species (ROS) by using the fluorescnet probe 2', 7'-dichlorofluorescein acetoxymethyl ester (DCF-AM), and observed the activity of antioxidant enzymes. Furthermore, several apoptotic signaling pathway with increased cytosolic calcium, alteration of mitochondrial membrane potential, cytochrome c release and activation of caspase 3 were also investigated. RESULTS: Resveratrol attenuated oxLDL-induced cytotoxicity, apoptotic features, generation of ROS and intracellular calcium accumulation. OxLDL-induced mitochondria membrane potential collapase, cytochrome c release and activation of caspase 3 in HUVECs were also suppressed by resveratrol pretreatment. CONCLUSIONS: Red wine intake may protect against oxLDL-induced dysfunction of endothelial cells.

Antioxidants↗

PubMed2005

Hypercholesterolemia, not metabolic syndrome, related to adhesion of monocytes to cultured endothelium in nondiabetic subjects.

The interaction of leukocytes and endothelium plays an important role in the development of atherosclerosis. Previous studies found that adhesion of leukocytes to endothelium is greater in subjects with hypercholesterolemia. It is not clear if metabolic syndrome, a contributing risk factor of cardiovascular disease, is related to this adhesion. Therefore, we conducted a study, in which 48 nondiabetic subjects were enrolled, to determine the relationship between leukocyte adhesion and the components of metabolic syndrome. After a 12-hour overnight fast, subjects' fasting blood was obtained for measurement of lipoprotein concentrations and glucose and insulin levels. Results of the number of monocyte adhesion to human umbilical vein endothelial cells were divided into high monocyte adhesion group and low monocyte adhesion group (n=24 in each group). Plasma concentrations of total cholesterol (245 +/- 5 vs 229+/- 4 mg/dL, P=.021) and low-density lipoprotein cholesterol (LDL-C) (162+/- 4 vs 146+/- 3 mg/dL, P=.003) were both higher in the high monocyte adhesion group than in the low monocyte adhesion group. Monocyte adhesion was significantly correlated to plasma concentrations of LDL-C (r=0.407, P=.002) but not to the total cholesterol (r=0.202, P=.085). However, there was no difference in monocyte adhesion to endothelium between subjects with or without metabolic syndrome, based on the modified criteria from the Adult Treatment Panel III of the National Cholesterol Education Program. Insulin resistance index, presented as homeostasis model assessment insulin resistance, and glucose or insulin responses to oral glucose tolerance test were similar between groups. Our study demonstrated that monocyte adhesion to endothelium has a stronger relationship with the plasma concentration LDL-C than with characteristics of metabolic syndrome.

Atherosclerosis↗

PubMed2005

Treatment of emphysematous pyelonephritis with broad-spectrum antibacterials and percutaneous renal drainage: an analysis of 10 patients.

BACKGROUND: This retrospective study was designed to determine the efficacy of broad-spectrum antibacterials combined with percutaneous renal drainage in the treatment of emphysematous pyelonephritis (EPN). METHODS: From July 1992 to September 2002, 10 patients (nine females and one male) with EPN were managed at our institution. All patients had diabetes and presented with fever and chills, flank pain or tenderness, vomiting, and altered consciousness. The diagnosis of EPN was confirmed by the presence of intraparenchymal and/or perinephric gas in imaging studies (kidney-ureter-bladder film, sonogram, and/or computed tomography scan). Broad-spectrum antibacterial therapy, combined with percutaneous renal drainage, was started in all patients. Follow-up studies consisted of computed tomography scan and technetium-labeled diethylenetriaminepentaacetic acid (DTPA) radioisotope renography. RESULTS: The outcome was good in all patients. Three patients underwent delayed nephrectomy due to non-functioning of the involved kidney. The DTPA radioisotope renography results (glomerular filtration rate of the diseased kidney/ contralateral healthy kidney) were 0/57 mL/min, 2.7/68.1 mL/min and 3.7/63.9 mL/min. CONCLUSION: Combined broad-spectrum antibacterial therapy and percutaneous renal drainage is a safe and effective treatment for EPN, especially in high-risk patients for whom nephrectomy under general anesthesia is not feasible.

Aged↗

PubMed2004

Urolithiasis in pregnancy.

BACKGROUND: The aim of this study was to review our experience in the diagnosis and management of urolithiasis in pregnant women, and to discuss safety, appropriate diagnostic tools and treatment modalities with review of literatures. METHODS: Nine women with pregnancy proved to have urolithiasis were included in this study. The diagnosis was made according to their symptoms and signs, and ultrasonographic findings. Conservative treatment with hydration, analgesics and antibiotics was applied initially, followed by some minimally invasive procedures, including percutaneous nephrostomy (PCN), double J (DBJ) stenting and ureterorenoscopy (URS), if initial treatment failed. RESULTS: All patients received conservative treatment at first, and 4 patients got well till delivery, another 5 patients needed further minimally invasive procedures; 1 of them received DBJ stenting, another 1 received PCN first and changed to DBJ stenting. The remaining 3 patients were treated by ureterorenoscopy with stone manipulation. All these 5 patiens had full-term delivery without obstetric sequela, except 1 patient who received left salpingoophrectomy due to left ovarian abscess. CONCLUSIONS: During pregnancy, urolithiasis is a diagnostic and therapeutic challenge. Clinical symptoms and signs are most important in establishing diagnosis, and ultrasound examination adds accuracy. Minimally invasive procedures (such as PCN, DBJ stenting, URS) can facilitate the successful management of patients requiring further intervention due to failure of conservative treatment.

Adult↗