Liqiang Guo

Impact of O6-methylguanine-DNA methyltransferase expression on the drug resistance of clear cell renal cell carcinoma

OBJECTIVE The deoxyribonucleic acid-repair protein O(6)-methylguanine-deoxyribonucleic acid methyltransferase is a major determinant of resistance of cells to various alkylating drugs. Its expression profile is different in different cancer types. Here, we studied the expression and function of O(6)-methylguanine-deoxyribonucleic acid methyltransferase in clear cell renal cell carcinoma. METHODS The expression of O(6)-methylguanine-deoxyribonucleic acid methyltransferase was evaluated in clear cell renal cell carcinoma tissues and cell lines by quantitative real-time polymerase chain reaction and immunohistochemistry. The relationship between O(6)-methylguanine-deoxyribonucleic acid methyltransferase expression and clinicopathological characteristics was analyzed. To further investigate the function of O(6)-methylguanine-deoxyribonucleic acid methyltransferase in clear cell renal cell carcinoma resistance to alkylating agents, siRNA targeting O(6)-methylguanine-deoxyribonucleic acid methyltransferase were used to silence the O(6)-methylguanine-deoxyribonucleic acid methyltransferase expression. RESULTS We found that O(6)-methylguanine-deoxyribonucleic acid methyltransferase is over-expressed in clear cell renal cell carcinoma tissues and cell lines. O(6)-methylguanine-deoxyribonucleic acid methyltransferase expression is related with tumor progression in clear cell renal cell carcinoma patients. Up-regulation of O(6)-methylguanine-deoxyribonucleic acid methyltransferase plays a critical role in primary resistance to alkylating agents. CONCLUSIONS The overexpression of O(6)-methylguanine-deoxyribonucleic acid methyltransferase contributes to resistance of clear cell renal cell carcinoma to standard chemotherapy. Our results have significance for understanding a new pathway of the development of drug resistance of clear cell renal cell carcinoma.

Significance of platelet distribution width as a severity marker of erectile dysfunction

Mean platelet volume (MPV) and Platelet distribution width (PDW) are potential markers in platelet activation. In present study, we aimed to evaluate MPV and PDW as potential severity markers for those patients who are complaining erectile dysfunction (ED). A total of 358 participants were enrolled in this study. The whole cohort was asked to complete the International Index of Erectile Function‐5 (IIEF‐5) questionnaire. The participants were classified into 3 groups: control group (n = 120), mild ED (n = 118) and severe ED (n = 120). We found in our cohort MPV and PDW were significantly higher in both mild ED group and severe ED group than control group (9.24 ± 0.70 and 9.71 ± 0.80 versus 8.56 ± 0.62 for MPV; 14.48 ± 1.29 and 14.98 ± 1.60 versus 12.86 ± 1.13 for PDW respectively). The MPV and PDW increased as the disease progressed. In the mild and severe ED groups, a significant inverse correlation was detected between the mean values of IIEF‐5 score and PDW. Furthermore, in the receiver operating characteristic curve analysis, the area under the curve of the MPV and PDW to predict severe ED was 0.818 and 0.848 respectively. Our study establishes a dose‐dependent association between the PDW and ED. Therefore, the PDW can serve as a potential marker for predicting the severity of ED.

Mean platelet volume might be an effective indicator of arterial erectile dysfunction

The aim of our study was to investigate the role of platelet parameters including mean platelet volume (MPV) and platelet count (PC) in the pathogenesis of penile arteriogenic erectile dysfunction (ED) and to evaluate the association between the platelet parameters and arteriogenic ED. There were 244 patients with ED (based on the International Index of Erectile Function [IIEF]-5 ≤21) and 60 healthy controls (IIEF-5 >21) enrolled. All participants were asked to undergo a laboratory examination, and penile vascular function was evaluated using penile color Doppler ultrasonography (pDUS). Among these ED patients, 24 patients with no abnormality on nocturnal penile tumescence (NPT) and 84 with normal vasculature or mixed vascular abnormalities were excluded. The other patients were classified into three groups as follows: control (n = 60), arteriogenic ED (n = 99), and venous leakage (n = 37) groups. MPV and PC were significantly higher in the arteriogenic ED group compared with the venous and control groups (P < 0.05). Receiver operating characteristic curve analysis revealed that the area under the curve for MPV to predict arteriogenic ED was 0.707. MPV ≥9.65 fl was recognized as a cut-off value for potential arteriogenic ED (sensitivity: 47.5%; specificity: 91.7%). A significant inverse correlation was detected between MPV and 10-min peak systolic velocity (PSV) (r = −0.34; P < 0.001) in the arteriogenic ED group. These findings suggest that the MPV might be a powerful indicator to predict and diagnose arteriogenic ED, and MPV may be a marker for ED when using pDUS.

Significance of penile hypersensitivity in premature ejaculation

To assess the correlation between penile hypersensitivity and premature ejaculation (PE), a total of 420 consecutive subjects attending our andrologic clinic for suspected PE were enrolled. The entire cohort was asked to complete the self-report intravaginal ejaculation latency time (IELT) by stopwatch. According to the IELT, the subjects were classified into 3 groups. Vibratory thresholds were recorded at the glans penis and penile shaft using a biothesiometer. We found that vibratory thresholds in the glans penis and penile shaft were significantly lower in both mild and severe PE group than in the control group (3.81 ± 0.57 and 3.54 ± 0.43 vs 4.73 ± 0.77 for glans penis p = 0.000; 3.64 ± 0.52 and 3.37 ± 0.50 vs 4.62 ± 0.69 for penile shaft p = 0.002). The vibratory threshold decreased as the disease aggravated. In the mild and severe PE groups, a significant positive correlation was detected between the mean values of IELT and the vibratory thresholds. Furthermore, in the receiver operating characteristics curve analysis, the area under the curve of the glans penis and penile shaft vibratory thresholds predicting severe PE were 0.852 and 0.893 respectively. Our study established a dose-dependent association between penile vibratory threshold and PE. Therefore, the vibratory threshold can serve as a potential marker for predicting the severity of PE.

The application of laparoscopic Doppler ultrasound during laparoscopic varicocelectomy in infertile men.

The aim of this study is to evaluate the benefits of laparoscopic Doppler ultrasound (LDU) application during laparoscopic varicocelectomy (LV), and to compare the surgical outcomes and complications between LDU-assisted LV (LDU-LV) and conventional LV for infertile patients with varicoceles; 147 infertile patients were randomly divided into two groups. Operative and postoperative parameters, semen parameters, and the pregnancy rate were compared. There were no differences in baseline demographics. The operative time was significantly longer in LDU-LV group than LV group. The incidence of postoperative hydrocele was 1.4% (1/72) in LDU-LV group versus 10.7% (8/75) in LV group, which showed a significant difference (P < 0.05). However, other surgical outcomes, such as postoperative hospital stay, postoperative recurrence, and testicular atrophy, were similar between the two groups. Sperm concentration and sperm motility were significantly increased in both groups at 3, 6, and 12 months after surgery (P < 0.01), and they were higher in LDU-LV than LV group in 12 months after surgery (34.21 ± 6.36 vs 29.99 ± 6.04 for concentration, P < 0.05; 40.72 ± 8.12 vs 37.31 ± 6.12 for motility, P < 0.05). Sperm morphology was comparable between the two groups. The pregnancy rate showed no significant difference (44.4% of the LDU-LV vs 37.3% of the LV, P > 0.05). In conclusion, compared with LV, LDU-LV could safely and effectively ligate all spermatic veins and preserve spermatic arteries without leading to high varicocele recurrence and postoperative hydrocele. Given the benefits that sperm counts as well as sperm motility favoring LDU-LV, we recommend that LDU should be routinely used as an effective tool to improve outcomes and safety of laparoscopic varicocelectomy.

AB210. The application of laparoscopic Doppler ultrasound during laparoscopic varicocelectomy in infertile patients

Objective To compare the surgical outcomes and complications between laparoscopic Doppler ultrasound assisted laparoscopic varicocelectomy (LDU-LV) and conventional LV for infertile patients with varicoceles. To examine the microanatomy of the spermatic cord within suprainguinal portion. Methods One hundred and forty-seven infertile patients with varicoceles were randomly divided into LDU-LV group and LV group. Operative and postoperative parameters, semen parameters and the pregnancy rate were compared. Results The operative time was significantly longer and the incidence of postoperative hydrocele was lower in LDU-LV group than LV group. The other surgical outcomes, such as postoperative hospital stay, postoperative varicocele recurrence, sperm morphology and pregnancy rate showed no difference. Sperm count and sperm motility were significantly increased in both groups at 3, 6 and 12 months after surgery, and they were higher in LDU-LV than LV group in 12 months after surgery. A mean number of 3.73 internal spermatic veins (ISVs), 2.25 lymphatics and 1.11 internal spermatic arteries (ISAs) were identified per cord at supra-inguinal level in patients from LDU-LV group. 68.6% of the ISAs were accompanied closely by a single ISV, 18.6% were surrounded by a dense network of adherent veins, only 12.8% were isolated and anterior to the veins. Conclusions LDU-LV could safely and effectively ligate all spermatic veins, preserve spermatic arteries and lymphatics, thereby improve sperm count and motility without leading to high recurrence and hydrocele. The number of ISVs at the supra-inguinal level is highly variable. Most ISAs are accompanied closely by a single ISV.