Biomedical subjects

Gang Ye

Publications and source records attributed to Gang Ye.

22 records · Page 2Linked to original sources

PubMed2003

Metallothionein prevents diabetes-induced deficits in cardiomyocytes by inhibiting reactive oxygen species production.

Many individuals with diabetes experience impaired cardiac contractility that cannot be explained by hypertension and atherosclerosis. This cardiomyopathy may be due to either organ-based damage, such as fibrosis, or to direct damage to cardiomyocytes. Reactive oxygen species (ROS) have been proposed to contribute to such damage. To address these hypotheses, we examined contractility, Ca(2+) handling, and ROS levels in individual cardiomyocytes isolated from control hearts, diabetic OVE26 hearts, and diabetic hearts overexpressing antioxidant protein metallothionein (MT). Our data showed that diabetic myocytes exhibited significantly reduced peak shortening, prolonged duration of shortening/relengthening, and decreased maximal velocities of shortening/relengthening as well as slowed intracellular Ca(2+) decay compared with control myocytes. Overexpressing MT prevented these defects induced by diabetes. In addition, high glucose and angiotensin II promoted significantly increased generation of ROS in diabetic cardiomyocytes. Chronic overexpression of MT or acute in vitro treatment with the flavoprotein inhibitor diphenyleneiodonium or the angiotensin II type I receptor antagonist losartan eliminated excess ROS production in diabetic cardiomyocytes. These data show that diabetes induces damage at the level of individual myocyte. Damage can be attributed to ROS production, and diabetes increases ROS production via angiotensin II and flavoprotein enzyme-dependent pathways.

Angiotensin II↗

PubMed2002

Optical urethrotomy for anterior urethral stricture under a new local anesthesia: intracorpus spongiosum anesthesia.

OBJECTIVES: To determine the feasibility of routinely performing internal urethrotomy for anterior urethral stricture under intracorpus spongiosum anesthesia in an outpatient setting. METHODS: In a consecutive series of 23 patients with anterior urethral stricture, a dosage of 3 mL of 1% lidocaine was slowly injected into the glans penis. Next, optical urethrotomy was performed immediately with a cold-cutting knife. The effect of this anesthetic technique was evaluated by questionnaire. RESULTS: Internal urethrotomy was successfully completed in all the patients. Twenty-two patients (95.7%) had no pain or discomfort. One patient reported minimal but tolerable discomfort while the tissue above the stricture was being cut. The anesthesia lasted for about 1.5 hours and was very satisfactory without any complications. CONCLUSIONS: Under intracorpus spongiosum anesthesia, optical urethrotomy can be routinely performed in an outpatient setting. With this new local anesthesia, internal urethrotomy is a safe, effective, simple, and inexpensive procedure for treatment of anterior urethral stricture.

Adult↗

PubMed2002

Overexpression of alcohol dehydrogenase exacerbates ethanol-induced contractile defect in cardiac myocytes.

Alcoholic cardiomyopathy is characterized by impaired ventricular function although its toxic mechanism is unclear. This study examined the impact of cardiac overexpression of alcohol dehydrogenase (ADH), which oxidizes ethanol into acetaldehyde (ACA), on ethanol-induced cardiac contractile defect. Mechanical and intracellular Ca(2+) properties were evaluated in ventricular myocytes from ADH transgenic and wild-type (FVB) mice. ACA production was assessed by gas chromatography. ADH myocytes exhibited similar mechanical properties but a higher efficiency to convert ACA compared with FVB myocytes. Acute exposure to ethanol depressed cell shortening and intracellular Ca(2+) in the FVB group with maximal inhibitions of 23.3% and 23.4%, respectively. Strikingly, the ethanol-induced depression on cell shortening and intracellular Ca(2+) was significantly augmented in the ADH group, with maximal inhibitions of 43.7% and 40.6%, respectively. Pretreatment with the ADH inhibitor 4-methylpyrazole (4-MP) or the aldehyde dehydrogenase inhibitor cyanamide prevented or augmented the ethanol-induced inhibition, respectively, in the ADH but not the FVB group. The ADH transgene also substantiated the ethanol-induced inhibition of maximal velocity of shortening/relengthening and unmasked an ethanol-induced prolongation of the duration of shortening/relengthening, which was abolished by 4-MP. These data suggest that elevated cardiac ACA exposure due to enhanced ADH expression may play an important role in the development of alcoholic cardiomyopathy.

Acetaldehyde↗

PubMed2002

[In vivo HSV-TK gene transfer and the therapeutic effects of ganciclovir on bladder cancer in mice with HSV-TK gene transfer].

OBJECTIVE: To explore an effective method for in vivo HSV-TK gene transfer and observe the therapeutic effect of ganciclovir (GCV) on bladder cancer in mice after receiving such gene transfer therapy. METHODS: Mice models bearing subcutaneous tumors of bladder cancer were established in 24 syngeneic mice, and HSV-TK gene transfer was performed by means of naked DNA plasmids, DNA-liposome complex or retroviral mediators respectively. GCV treatment was administered in all the mice and its effect on the growth of the tumor was subsequently observed. RESULTS: Gene transfer therapies by DNA-liposome complex and retroviral mediators both significantly inhibited the growth of the tumor by 54% and 68% respectively, and the survival of the mice was prolonged by 28.81% and 44.16% (P<0.05). The effect of gene transfer by naked DNA plasmids was not obvious (P>0.05). CONCLUSION: Gene transfer therapies by DNA-liposome complex and retroviral vectors supplemented by GCV treatment are effective therapeutic modalities against bladder cancer.

Animals↗