[Comparison of efficacy and safety of transurethral thulium laser vapoenucleation of prostate and transurethral thulium laser enucleation of prostate in the treatment of benign prostatic hyperplasia]

Objective: To compare early outcomes between transurethral thulium laser vapoenucleation of prostate and transurethral thulium laser enucleation of prostate for the treatment of benign prostatic hyperplasia (BPH). Methods: Retrospective analysis was conducted on the clinical data of 1 638 BPH patients admitted to the Department of Urology of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine from January 2018 to December 2021. There were 916 patients underwent transurethral thulium laser vapoenucleation of prostate (ThuVEP group) and 722 patients underwent transurethral thulium laser enucleation of prostate (ThuLEP group). The operation time, eliminated tissue weight, surgical complications, duration of post-operative catheter implantation were compared between the two groups. The improvement of International Prostate Symptom Score (IPSS), Quality of Life Index (QoL), maximum uroflow rate (Qmax) and post-void residual urine volume (PVR) at 1 month after operation was compared between the two groups. Results: There were no significant differences in age, preoperative and 1-month postoperative prostate volume, IPSS score, QoL score, Qmax, and PVR between the ThuVEP and ThuLEP group (all P>0.05). There were no significant differences in perioperative indicators such as operation time, cutting or enucleation time, tissue crushing time, tissue weight, hemoglobin change, catheter indwelling time, and postoperative hospital stay between ThuVEP group and ThuLEP group (all P>0.05). The incidence of minor gross hematuria after extubation in the ThuVEP group was 7.8% (56/916), which was lower than 9.4% (65/722) in the ThuLEP group (P=0.026); the incidence of temporary incontinence at 1 month after surgery was 5.2% (38/916) in ThuVEP group, lower than 11.9% (86/722) in ThuLEP group (P<0.001). A total of 3 patients (0.4%) in ThuLEP group required operative intervention for severe post-operation bleeding, but none of ThuVEP group suffered from this kind of surgical complications. Conclusions: ThuVEP has similar efficacy with ThuLEP for the treatment of BPH. ThuVEP can significantly reduce the incidence of post-operation temporary urine incontinence, and has much superiority in stanching bleeding.

[Analysis of dyslipidemia management status in atrial fibrillation patients with very high and high risk of atherosclerotic cardiovascular disease]

Objective: To analyze the status of statins use and low-density lipoprotein cholesterol (LDL-C) management in patients with atrial fibrillation (AF) and very high/high risk of atherosclerotic cardiovascular disease (ASCVD) from Chinese Atrial Fibrillation Registry (CAFR). Methods: A total of 9 119 patients with AF were recruited in CAFR between January 1, 2015 to December 31, 2018, patients at very high and high risk of ASCVD were included in this study. Demographics, medical history, cardiovascular risk factors, and laboratory test results were collected. In patients with very high-risk, a threshold of 1.8 mmol/L was used as LDL-C management target and in patients with high risk, a threshold of 2.6 mmol/L was used as LDL-C management target. Statins use and LDL-C compliance rate were analyzed, multiple regression analysis was performed to explore the influencing factors of statins use. Results: 3 833 patients were selected (1 912 (21.0%) in very high risk of ASCVD group and 1 921 (21.1%) in high risk of ASCVD group). The proportion of patients with very high and high risk of ASCVD taking statins was 60.2% (1 151/1 912) and 38.6% (741/1 921), respectively. Attainment rate of LDL-C management target in patients with very high and high risk were 26.7% (511/1 912) and 36.4% (700/1 921), respectively. Conclusion: The proportion of statins use and attainment rate of LDL-C management target are low in AF patients with very high and high risk of ASCVD in this cohort. The comprehensive management in AF patients should be further strengthened, especially the primary prevention of cardiovascular disease in AF patients with very high and high risk of ASCVD.

[Laser treatment of benign prostate hyperplasia and its related problems after operation]

Benign prostate hyperplasia (BPH) is the main cause of lower urinary tract symptoms in elder man. As the progression of aging society, the number of BPH patient is getting larger, while there are some patient needs surgical interventions. Regarding as the main surgical intervention, trans-urethral resection of the prostate is gradually developing and focusing on minimal invasive, safety and long-term sustainability. As the surgical energy medium developing, the traditional electronic heat energy has been replaced by laser. Laser has different wavelength which suit for different operational ways separately, and it was applied on more and more surgical ways. Although the revolution of operational techniques and equipment make choices of surgeons diverse, the prevention and treatment of BPH post-surgical problems is still the clinical key points. We concluded the laser treatment on BPH and its post-surgical problem, and try to provide methods and idea for the application of clinical laser applications.

[A new understanding of wound repair after surgery for benign prostatic hyperplasia]

Benign prostatic hyperplasia (BPH) is one of the most common diseases in elderly men. Transurethral resection of prostate (TURP), as an important BPH treatment, is also the most effective way to relieve prostatic obstruction. However, postoperative complications, such as lower urinary tract symptoms (LUTS), infection, hematuria and bladder neck contracture, may still occur, which seriously impact the therapeutic effect and patients' quality of life. The wound healing after BPH surgery is closely associated with the occurrence of postoperative complications. Therefore, comprehensively understanding the influencing factors of wound healing and designing tailored interventions will be particularly important for reducing postoperative complications of BPH.

[The thromboembolism risk of low-risk atrial fibrillation patients with different clinical characteristics]

Objective: This study explored the thromboembolism risk of low-risk atrial fibrillation (AF) patients (CHA₂DS₂-VASc score of 0 or 1 for male and 1 or 2 for female) with different clinical characteristics to provide the basis for anticoagulation decision-making in these patients. Methods: We prospectively enrolled consecutive 2 862 nonvalvular low-risk AF patients between August 2011 to December 2018 in China-AF (China Atrial Fibrillation Registry) Study, their CHA₂DS₂-VASc score was 0 or 1 for male and 1 or 2 for female. According to their age, sex, presence or absence of hypertension, diabetes mellitus, congestive heart failure, and vascular disease at the time of enrolling, patients were divided into CHA₂DS₂-VASc score 0 score group, 1 score group, and 2 score group. Patients were followed up every 6 months by outpatient clinic visit or telephone interview. The outcome was a thromboembolic event, including ischemic stroke and systemic embolism. Univariate Cox regression analysis was used to compare the thromboembolism risk between the patients with different risk factors and CHA₂DS₂-VASc score 0 group. Results: A total of 2 862 low-risk atrial fibrillation patients were enrolled in this study. 915 patients (32.0%) were female, and age was (55.0±10.7) years old. There were 933 patients (32.6%) in CHA₂DS₂-VASc score 0 group, 1 401 patients (49.0%) in score 1 group and 528 patients (18.5%) in score 2 group. During follow-up (median 1.5 years, 5 811.82 person-years), 33 cases of thromboembolic events were recorded, the annual rate of thromboembolism was 0.57% (95%CI 0.40%~0.80%). The number of thromboembolic events in patients with CHA₂DS₂-VASc score 0, 1 and 2 were 8, 11 and 14, respectively, and the annual thromboembolism event rates were 0.40% (95%CI 0.20%-0.81%), 0.39% (95%CI 0.22%-0.71%) and 1.34% (95%CI 0.80%-2.27%), respectively. The risk of thromboembolism of CHA₂DS₂-VASc score 2 group (HR=3.53, 95%CI 1.48-8.44; P=0.005), especially female patients aged 65-74 years in CHA₂DS₂-VASc score 2 group (HR=2.67, 95%CI 1.63-4.38; P<0.000) was significantly higher than that in patients of CHA₂DS₂-VASc score 0 group. Conclusion: Low-Risk Atrial Fibrillation patients with CHA₂DS₂-VASc score 2, especially female patients aged 65-74 years old with CHA₂DS₂-VASc score 2 are at higher risk of thromboembolism in low-risk AF patients. For such patients, intensified oral anticoagulant therapy might be helpful to reduce the risk of thrombolism.

[Impact of history of hypertension and blood pressure levels on the risk of thromboembolism in nonvalvular atrial fibrillation patients]

Objective: To investigate the impact of history of hypertension and blood pressure levels on the thromboembolism risk in the setting of nonvalvular atrial fibrillation (NVAF). Methods: China Atrial Fibrillation Registry Study prospectively enrolled 25 512 atrial fibrillation (AF) patients between August 2011 and December 2018. After exclusion of patients with valvular AF, hypertrophic cardiomyopathy, receiving anticoagulation or ablation therapy at the enrollment, 7 757 patients were included in analysis. The primary endpoint was the time to the first occurrence of ischemic stroke or systemic embolism. Cox proportional hazards models were performed to evaluate whether a history of hypertension or blood pressure levels were independently associated with thromboembolism. Results: During a mean follow up of (35±25) months, 455 （5.9%）thromboembolic events occurred. The crude incidence rate of thromboembolism in patients with a history of hypertension was higher than that in patients without hypertension (2.38 vs. 1.35 per 100 patient-years, χ²=16.8，Log-rank P<0.001). Patients were further divided into 4 groups according to systolic blood pressure (SBP) levels at baseline, the crude incidence rate of thromboembolism significantly increased in proportion to the elevation of SBP levels (χ²=17.9，Log-rank P<0.001). However, there was no significant difference in thromboembolism risk among 4 groups stratified by diastolic blood pressure (DBP) levels (χ²=0.6，Log-rank P=0.907). Multivariable regression analysis showed that history of hypertension was independently associated with a 27% higher risk of thromboembolism (HR=1.27, 95%CI 1.01-1.61, P=0.045). Patients with SBP≥140 mmHg (1 mmHg=0.133 kPa) was associated with 36% higher risk of thromboembolism than patients with SBP<120 mmHg (HR=1.36, 95%CI 1.02-1.82, P=0.036). However, patients with SBP 120-129 mmHg or 130-139 mmHg were not at a higher risk of thromboembolism as compared to the patients with SBP<120 mmHg (SBP 120-129 mmHg: HR=1.23, 95%CI 0.90-1.67, P=0.193; SBP 130-139 mmHg: HR=1.30, 95%CI 0.95-1.77, P=0.098). In addition, DBP levels were not independently associated with the increased thromboembolism risk. Conclusion: A history of hypertension and SBP≥140 mmHg are independent predictors of thromboembolism risk in patients with NVAF. These results indicate that intensive efforts to lower SBP below 140 mmHg might be an important strategy to reduce the risk of stroke in patients with NVAF.

[Association between duration of digoxin use and adverse outcomes among Chinese patients with atrial fibrillation]

Objective: We aimed to explore the impact of digoxin use on outcomes in Chinese patients with atrial fibrillation (AF). Methods: We used the dataset from the Chinese Atrial Fibrillation Registry, a prospective, multicenter, hospital-based registry study. According to the inclusion and exclusion criteria, 10 472 eligible patients enrolled from August 2011 to December 2016 were included in this ancillary study. The patients were classified into three groups according to the status of digoxin use at study enrollment, patients already receiving digoxin before registry were represented as continuous group, patients initiated on digoxin for the first time were represented as newly group, and patients without digoxin prescription at enrollment were represented as control group. Patients were followed by telephone or outpatient service every 6 months. Kaplan-Meier survival analysis and Cox proportional hazards regression models were used to investigate the association of digoxin use with adverse outcomes (all-cause death, cardiovascular death and cardiovascular hospitalization). Results: In the overall study population, men accounted for 42.8%, and the average age was (66.9±11.8) years. There were 777（7.42%）patients in continuous group, 375 (3.58%) patients in newly group, and 9 320 (89.00%) patients in control group. Compared with the control group, the patients in the newly group and the continuous group were older, had faster heart rate, lower estimated glomerular filtration rate, higher proportion of persistent atrial fibrillation, heart failure, renal insufficiency, diabetes mellitus, ischemic stroke, coronary heart disease, vascular disease and bleeding history. At the same time, the patients in the newly group and the continuous group were treated more often with anticoagulants, antiplatelet drugs, ACE inhibitors or angiotensin receptor blockers, beta-receptor blockers while the proportion of antiarrhythmic drugs was lower as compared to control group (P<0.05). During a median follow-up of 36 months (interquartile range: 18-48 month), risk of all-cause mortality was significantly higher in newly group compared to control group (7.3% vs. 4.7%, P<0.05), the rates of all-cause mortality, cardiovascular death and cardiovascular hospitalization were all higher in continuous group than in control group (8.0% vs. 4.7%; 4.7% vs. 3.0%; 16.7% vs. 11.8%; P all<0.05). After adjustment for age, male, body mass index, blood pressure, heart rate, renal function, AF type, history of stroke, heart failure, diabetes, coronary artery disease and other drugs treatment, the association between newly group and adverse outcomes was not significant, however, digoxin use was associated with increased all-cause mortality (HR 1.26; 95%CI 1.04-1.56; P=0.019), cardiovascular death (HR 1.38; 95%CI 1.08-1.77, P =0.01), and cardiovascular hospitalization (HR 1.10; 95%CI 1.06-1.52, P=0.02) in continuous group. Conclusion: Continuous digoxin use is associated with a significant increase in adverse outcomes among Chinese patients with atrial fibrillation.

[Efficacy and safety of low-intensity pulsed ultrasound at different intervals by mechanical force in treating erectile dysfunction: a preliminary study]

Objective: To study the efficacy and safety of low-intensity pulsed ultrasound (LIPUS) at different intervals by mechanical force in treating erectile dysfunction (ED). Method: Forty patients with mild to moderate ED were randomized in a 1∶1 ratio to receive 16-treatment sessions of LIPUS in group A and group B, applied 3 times per week and 2 times per week, respectively. End-point assessments were made at 8th week after treatment. Efficacy were evaluated using International Index of Erectile Function-Erectile Function domain score (IIEF-EF), Erectile Hardness Score (EHS), Self-Esteem and Relationship Questionnaire (SEAR), Sexual Encounter Profile (SEP), Global Assessment Question (GAQ), and pain were assessed by Visual Analogue Score (VAS).Treatment response was confirmed by a minimal clinically importance difference (MCID) at 8th week. Results: Compared with baseline, IIEF-EF score [(17.1±5.48 vs 23.4±3.75, P<0.05) and (18.9±4.34 vs 24.1±4.32, P<0.05)], proportion of EHS 4 [(0 vs 40%, P<0.05) and (16.7% vs 55.6%, P<0.05)], and Overall Relationship score [(50.6 vs 67.5, P<0.05) and (44.4 vs 70.1, P<0.05)] were significantly improved at 8th week in two groups, respectively. Compared with baseline, the positive responses to SEP-3 increased significantly at 8th week in two groups (50.0% vs 80.0%,P<0.05) and (44.4% vs 88.9%, P<0.05), respectively. The positive responses to GAQ-2 were 90.0% and 88.9% at 8th week in two groups, respectively. There were no significant differences in IIEF-EF, EHS, SEAR, SEP and GAQ at 8th week between two groups. There was no significant difference in treatment response using MCID between two groups at end-point (80.5% vs 77.5%). The treatment duration for full sessions were 2.5 weeks less in group A than group B. No adverse effects were reported in all cases. Conclusion: LIPUS at two different intervals is effective and safe for mild to moderate ED, and the regimen at 3 times per week can achieve quite good effect in relatively short duration,while the long-term effects is still be clarified in further study.

[Risk factors for recurrent hospitalizations of patients with atrial fibrillation]

Objective: To determine the predictors of recurrent hospitalizations among atrial fibrillation (AF) patients. Methods: We analyzed data from the Chinese Atrial Fibrillation Registry (CAFR), a prospective cohort study involving non-valvular atrial fibrillation (NVAF) patients from Augest 2011 to December 2017. A total of 5 349 NVAF patients with a minimum of 48 months follow-up were included for analysis. Data including patient demographics, complications, medical and ablation history were collected. The maximum number of all-cause hospitalizations within one-year for each patient served as the primary endpoint. Patients hospitalized less than twice within one-year were defined as non-recurrent hospitalizations group, those hospitalized at least twice within one-year were definned as recurrent hospitalizations group. Logistic regression model was used to identify associated risk factors for recurrent hospitalizations. Results: Of 5 349 NVAF patients, those hospitalized for 0, 1, 2, 3, 4 and at least 5 times within one-year was 2 703 (50.5%), 1 776 (33.2%), 642 (12.0%), 161(3.0), 52 (1.0%), 15 (0.3%), respectively. Eight hundred and seventy (16.3%) patients were included in recurrent hospitalizations group, 4 479 (83.7%) patients were included in non-recurrent hospitalizations group. Compare with non-recurrent hospitalizations group, patients in recurrent hospitalizations group was more likely to be older and female, more frequently had a history of hypertension, heart failure, coronary heart disesase, ischaemic stroke/transient ischaemic attack, diabetes mellitus, peptic ulcer, a AF duration for more than 1 year, medication including drugs for ventricular rate control, statin, angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blocker (ARB) and higher CHA(2)DS(2)-VASc scores (P<0.05), but less frequently had higher education, a history of drinking, smoking and ablation (P<0.05). Multivariable analysis showed that age 50-64 (OR=1.47, 95%CI 1.20-1.80), age≥65 (OR=1.89, 95%CI 1.50-2.38), female (OR=1.21, 95%CI 1.01-1.46), hypertension history (OR=1.42, 95%CI 1.16-1.74), heart failure history (OR=1.73, 95%CI 1.37-2.18), coronary heart disease history (OR=1.63, 95%CI 1.31-2.03), peptic ulcer history (OR=2.00, 95%CI 1.18-3.39) were independent risk factors for recurrent hospitalizations, while higher education (college or above) (OR=0.82, 95%CI 0.69-0.99) was the protective factor for recurrent hospitalizations. Conclusions: Nearly 1 in 6 of AF patients were admitted to hospital more than once within one year in this NVAF cohort. Age≥50, female, hypertension history, heart failure history, coronary heart disease history, peptic ulcer history are associated with an increased risk of recurrent hospitalizations.

[Screening of candidate proteins related to maturation arrest based on iTRAQ technique]

Objective: To screen candidate proteins related to maturation arrest of human spermatogenesis. Methods: From March 2015 to September 2016, 3 cases of obstructive azoospermia and 3 cases of patients with maturation arrest, who were admitted to the Shanghai General Hospital, were selected for proteomic sequencing, and the sequencing results were identified and analyzed. Results: A total of 125 differentially expressed proteins were identified, of which 21 were up-regulated and 104 were down-regulated. Analysis of biological process shows that differentially expressed proteins participate in reproductive and developmental processes. Participation in reproductive processes accounts for 29.00% of the difference proteins. Participation in the development process accounted for 41.00% of the difference proteins. Cell component(CC) analysis showed that 68.00% different proteins were attached to organelles. Molecular function analysis showed that the binding function accounted for 85.00% of the differential proteins. The proportion of proteins involved in transportation, regulation of enzyme activity and anti-oxidation were 11.05%, 4.62% and 8.34% respectively. Signal pathways involved in sperm deformation included MAPK pathway, Ca(2+)/calmodulin pathway. Conclusions: The candidate proteins and its associated signaling pathways were selected. The abnormal structuration and function of mature arrest could lead to severe male infertility.

[Comparative observation of thulium laser resection of the prostate-tangerine technique and transurethral resection of the prostate for the treatment of benign prostatic hyperplasia of various sizes]

Objective: To compare the efficiency and safety of thulium laser resection of the prostate-tangerine technique (TmLRP-TT) and transurethral resection of the prostate (TURP) for the treatment of benign prostatic hyperplasia (BPH) of various sizes. Methods: Clinical data of 249 BPH patients received TmLRP-TT or TURP were retrospectively collected. Patients were divided into small prostate group [prostate volume (PV)<40 ml], medium prostate group (40 ml≤PV<80 ml) and large prostate group (PV ≥ 80 ml) based on transrectal ultrasound (TRUS) results. Age, PV, Prostate-specific antigen (PSA), International prostate symptom score (IPSS), Quality of life (QoL), maximum of flow rate (Q(max)) and post-void residual urine (PVR) of patients received TmLRP-TT or TURP in each group were analyzed, as well as the perioperative data including operation time, hemoglobin and serum sodium level, transfusion, postoperative length of indwelling catheter and postoperative hospital stay. Furthermore, the postoperative complication rates of patients received the two operative methods in each group up to follow-up of 6 months were compared. Results: As for baseline indicators, there were no significant differences regarding age, prostate volume, PSA, IPSS, QoL, Qmax and PVR of patients received TmLRP-TT or TURP in each group (all P>0.05). In the small prostate group, there were no significant differences with operation time, hemoglobin and serum sodium level, transfusion, postoperative length of indwelling catheter and postoperative hospital stay received TmLRP-TT or TURP (all P>0.05). For the medium prostate group, patients received TmLRP-TT underwent longer operation time [(67.4±15.1) vs (57.5±11.5) min, P<0.001], but shorter length of indwelling catheter [(1.5±0.6) vs (3.1±0.9) d, P<0.001] and postoperative hospital stay [(3.5±0.9) vs (5.6±1.0) d, P<0.001], and there were no significant differences regarding transfusion rate (3/73 vs 1/78, P=0.280), hemoglobin [(9.8±9.0) vs (12.2±9.6) g/L, P=0.107] and serum sodium decrease [(2.07±3.65) vs (2.97±3.35) mmol/L, P=0.373]. In the large prostate group, patients received TmLRP-TT also underwent longer operation time [(86.5±14.3) vs (76.7±14.6) min, P=0.022], but less hemoglobin [(11.3±13.8) vs (23.3±15.0) g/L, P=0.006] and serum sodium decrease [(2.41±2.67) vs (4.00±6.22) mmol/L, P=0.042], lower transfusion rate (5/27 vs 0/24, P=0.026), and shorter length of indwelling catheter [(1.8±0.7) vs (4.3±1.5) d, P<0.001] as well as postoperative hospital stay [(3.7±1.1) vs (6.1±1.7) d, P<0.001]. Less overall complications were encountered in the medium (38/73 vs 24/78, P=0.008) and large (26/27 vs 10/24, P<0.001) prostate group who received TmLRP-TT, which was not seen in the small prostate group (P=0.589). Conclusions: TmLRP-TT and TURP are similarly efficient for the treatment of BPH of various sizes. For BPH patients with medium and large prostate, TmLRP-TT demonstrated significant advantages in reducing the overall complications, although the operation time was slightly longer.

Formation of iodinated trihalomethanes during breakpoint chlorination of iodide-containing water

This study investigated the formation of toxic iodinated trihalomethanes (I-THMs) during breakpoint chlorination of iodide-containing water. Impact factors including I^- concentration, natural organic matter (NOM) concentration and type, pH as well as Br^-/I^- molar ratio were systematically investigated. Moreover, the incorporation of I^- into I-THM formation was also calculated. The results showed that I-THM formation varied in different zones of the breakpoint curves. I-THMs increased with increasing chlorine dosage to breakpoint value and then dropped significantly beyond it. Iodoform (CHI₃) and chlorodiiodomethane (CHClI₂) were the major I-THMs in the pre-breakpoint zone, while dichloroiodomethane (CHCl₂I) was the dominant one in the post-breakpoint zone. The formation of I-THMs increased remarkably with I^- and dissolved organic carbon (DOC) concentrations. More bromine-containing species were formed as Br^-/I^- molar ratio increased from 0.5 to 5. In addition, the major I-THM compound shifted from CHCl₂I to the more toxic CHClBrI. As pH increased from 6.0 to 8.0, I-THM formation kept increasing in the pre-breakpoint zone and the speciation of I-THMs changed alongside the breakpoint curves. The incorporation of I^- during breakpoint chlorination was highly dependent on chlorine, I^-, and NOM concentrations, NOM type, solution pH and Br^-/I^- molar ratio.

[Effectiveness of microsurgical crossover anastomosis in treating complicated obstructive azoospermia]

Objective: To evaluate the efficacy and safety of microsurgical crossover vasovasostomy in treating complicated obstructive azoospermia. Methods: The data of 14 patients with complicated obstructive azoospermia treated with microsurgical crossover vasovasostomy were reviewed from October 2012 to March 2016.Ten of them underwent microsurgical crossover vasovasostomy. Intraoperative exploration revealed that 2 patients had vas deferens injury and contralateral testicular atrophy or epididymal obstruction due to previous hernia repair; 7 patients had obstruction of intracorporeal vas deferens on one side and epididymal obstruction on the other side; the other 1 patient had unilateral vasal obstruction with contralateral epididymal obstruction. Furthermore, 4 patients underwent microsurgical crossover vasoepididymostomy, including 3 patients who had obstruction at caput epididymis on one side, and obstruction at cauda epididymis and distal vas deferens on the other side; the other patient had absence of vas deferens in the scrotum on one side, and testicular atrophy on the other side. Regular follow-up visits were conducted after the surgery. Results: Two patients were lost to follow-up; the other 12 patients were follow-up for an average of 11 (range: 2-23) months. In the 10 cases receiving microsurgical crossover vasovasostomy (including 2 patients lost to follow-up), 1 has not undergone semen re-analysis, 6 were confirmed patent, including 3 reporting spontaneous pregnancy. The patency rate in the 4 patients receiving microsurgical crosseover vasoepididymostomy was 2/4, with 1 patient reporting spontaneous pregnancy. There was no complaint of discomfort or complications following the surgery. Conclusions: Microsurgical crossover anastomosis may be effective and safe for patients with complicated obstructive azoospermia, according to preoperative assessment and intraoperative exploration. It allows natural conception for patients with refractory infertility. The microsurgical crossover anastomosis could be an effective therapy to achieve satisfactory patency of vas deferens.

Degradation of acrylamide during chlorination as a precursor of haloacetonitriles and haloacetamides

Acrylamide is a monomer of polyacrylamide, which is widely used in the water treatment process as a flocculant. The degradation kinetics and formation of disinfection by-products (DBPs) during acrylamide chlorination were investigated in this study. The reaction between chlorine and acrylamide followed a pseudo-first-order kinetics. A kinetic model regarding acrylamide chlorination was established and the rate constants of each predominant elementary reaction (i.e., the base-catalyzed reaction of acrylamide with ClO^- as well as the reactions of acrylamide with HOCl and ClO^-) were calculated as 7.89×10⁷M^-2h^-1, 7.72×10¹M^-1h^-1, and 1.65×10³M^-1h^-1, respectively. The presence of Br^- in water led to the formation of HOBr and accelerated the rate of acrylamide degradation by chlorine. The reaction rate constant of acrylamide with HOBr was calculated as 1.33×10³M^-1h^-1. The degradation pathways of acrylamide chlorination were proposed according to the intermediates identified using ultra-performance liquid chromatography and electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). Five chlorinated DBPs including chloroform (CF), dichloroacetonitrile (DCAN), trichloroacetonitrile (TCAN), dichloroacetamide (DCAcAm), and trichloroacetamide (TCAcAm) were identified during acrylamide chlorination. The formation of CF, DCAN, DCAcAm, and TCAcAm kept increasing, while that of TCAN increased and then decreased with increasing reaction time. As the chlorine dosage increased from 0.75 to 4.5mM, DCAN became the dominant DBP. Large amounts of CF, DCAN, and TCAN were formed at basic pHs. The hydrolysis of DCAN and TCAN led to the formation of DCAcAm and TCAcAm, respectively. The results of this study elucidated that acrylamide can be a precursor for the formation of haloacetonitriles (HANs) and haloacetamides (HAcAms) during drinking water treatment.

Degradation of acrylamide by the UV/chlorine advanced oxidation process

The degradation of acrylamide (AA) during UV/chlorine advanced oxidation process (AOP) was investigated in this study. The degradation of AA was negligible during UV irradiation alone. However, AA could be effectively degraded and mineralized during UV/chlorination due to the generation of hydroxyl radicals (OH). The degradation kinetics of AA during UV/chlorination fitted the pseudo-first order kinetics with the rate constant between AA and OH radicals being determined as 2.11 × 10⁹ M^-1 s^-1. The degradation rate and mineralization of AA during UV/chlorination were significantly promoted at acidic conditions as well as increasing chlorine dosage. The volatile degradation products of AA during UV/chlorination were identified using gas chromatography-mass spectrometry and the degradation pathways were then proposed accordingly. The formation of disinfection by-products (DBPs) in Milli-Q water and tap water during UV/chlorination of AA was also investigated. The DBPs included chloroform, dichloroacetonitrile, trichloroacetonitrile, 2,2-dichloroacetamide and 2,2,2-trichloroacetamide. Furthermore, the variations of AA degradation during UV/chlorination in different real water samples were evaluated.

Chlor(am)ination of iopamidol: Kinetics, pathways and disinfection by-products formation

The degradation kinetics, pathways and disinfection by-products (DBPs) formation of iopamidol by chlorine and chloramines were investigated in this paper. The chlorination kinetics can be well described by a second-order model. The apparent second-order rate constants of iopamidol chlorination significantly increased with solution pH. The rate constants of iopamidol with HOCl and OCl^- were calculated as (1.66 ± 0.09) × 10^-3 M^-1 s^-1 and (0.45± 0.02) M^-1 s^-1, respectively. However, the chloramination of iopamidol fitted well with third-order kinetics and the maximum of the apparent rate constant occurred at pH 7. It was inferred that the free chlorine (i.e., HOCl and OCl^-) can react with iopamidol while the combined chlorine species (i.e., NH₂Cl and NHCl₂) were not reactive with iopamidol. The main intermediates during chlorination or chloramination of iopamidol were identified using ultra performance liquid chromatography - electrospray ionization-mass spectrometry (UPLC-ESI-MS), and the destruction pathways including stepwise deiodination, hydroxylation as well as chlorination were then proposed. The regular and iodinated DBPs formed during chlorination and chloramination of iopamidol were measured. It was found that iodine conversion from iopamidol to toxic iodinated DBPs distinctly increased during chloramination. The results also indicated that although chloramines were much less reactive than chlorine toward iopamidol, they led to the formation of much more toxic iodinated DBPs, especially CHI₃.

Formation of organic chloramines during chlor(am)ination and UV/chlor(am)ination of algae organic matter in drinking water

Surface water are frequently subjected to problems of algal blooms and release of algae organic matter (AOM) from the algae cells, which cause many water quality issues. This study investigated the formation of organic chloramines and nitrogenous disinfection by-products (N-DBPs) during chlor(am)ination and UV/chlor(am)ination of AOM in drinking water. AOM caused higher organic chloramine formation than humic acid and fulvic acid during chlor(am)ination. The formation of organic chloramines increased first and then decreased with the increase of free chlorine dosage, but kept increasing with the increase of NH2Cl dosage. During AOM chlorination, the formation of organic chloramines kept decreasing as the reaction time went by, and the maximum organic chloramine proportion (79.1%) in total chlorine occurred at 8 h. However, during AOM chloramination, the formation of organic chloramines increased first, decreased in the following and then increased again as the reaction time went by, and the maximum organic chloramine proportion (22.1%) in total chlorine occurred at 24 h. UV irradiation pretreatment did not effectively influence organic chloramine formation during AOM chlor(am)ination, but accelerated the degradation of organic chloramines during chloramination. Besides, UV pretreatment enhanced the formation of N-DBPs during the subsequent chlor(am)ination of AOM, especially dichloroacetonitrile.

[Effect of double-J stent indwelling time in treatment of ureteric calculi complicated with infection]

OBJECTIVE

To evaluate the effect and double-J stent indwelling time in the treatment of acute upper urinary tract infection caused by ureteral calculi.

METHODS

A prospective non-randomized controlled study was carried out. From January 2011 to August 2015, a total of 142 patients treated in Department of Urology of Shanghai First People's Hospital for ureteral calculi with systematic inflammatory response syndrome were divided into double-J stent indwelling 7 days group (n=63) and double-J stent indwelling > 7 days group (n=79). The preoperative routine blood test, urinalysis, and urine culture, the urinalysis and urine culture immediately after double-J indwelling, and the routine blood test, urinalysis, and urine culture 7 days after indwelling were compared between the two groups. Postoperative complications after lithotripsy were analyzed.

RESULTS

There were no statistically significant differences in preoperative blood white blood cell (WBC) count, urine WBC count, and positive bacterial culture between the two groups (all P>0.05). Seven days after double-J stent indwelling, significant improvement was seen in both the 7 d group and the >7 d group in blood WBC count, urine WBC count, and positive urine culture [(8.1±1.7) vs (14.8±3.1) ×10(9)/L, (356±44) vs (3 077±643)/μl, 1.6% vs 52.4%; (7.9±1.1) vs (15.1±3.8) ×10(9)/L, (363±52) vs (3 122±805)/μl, 3.8% vs 48.1%], and infection was managed effectively, while no statistically significant inter-group differences were observed. There was no significant difference in stone clearance rate between the two groups (96.8% vs 96.2%, P>0.05). There was no significant difference in the incidence of postoperative complications, especially infectious complications (all P>0.05).

CONCLUSIONS

Indwelling double-J stents for 7 days could effectively manage the infection in patients with acute upper urinary tract infection secondary to ureteral calculi. These patients can be treated with lithotripsy safely. The time of double-J stent indwelling could be shortened.

[Situation of long-term use of oral anticoagulation among atrial fibrillation patients with stroke in different level hospital]

OBJECTIVE

To investigate the current situation, time trends and factors associated with long-term use of oral anticoagulation (OAC) among atrial fibrillation (AF) patients with ischemic stroke.

METHODS

We used the dataset from the CAFR (Chinese Atrial Fibrillation Registry), a prospective, multicenter, hospital-based registry study involving 20 tertiary and 12 nontertiary hospitals in Beijing. In brief, 380 consecutive AF patients with following ischemic stroke were enrolled from 2003 to 2014.Patients with valvular AF, radiofrequency catheter ablation history or contraindications of OAC were excluded. We divided the patients into two groups according to hospital level, and investigated the rate of OAC use and its change over time in patients who had indication, the factors including patient characteristics and hospital level associated with OAC use were also analyzed.

RESULTS

Overall oral anticoagulation use rate was 27.71%, which dropped to 22.11% and 15.26% at 6 months and 12 months, respectively.A total of 298 participates were enrolled from tertiary hospitals (78.42%), and 82 were enrolled from nontertiary hospitals. The status of OAC use in tertiary hospitals was better than nontertiary hospitals (32.66% vs 7.32%, P<0.001). Multivariable analysis showed better oral anticoagulation use was independently associated with higher-level hospitals (odds ratio 1.785, 95% confidence interval 1.026-3.106, P=0.040), and history of heart failure (odds ratio 2.247, 95% confidence interval 1.235-4.090, P=0.008).

CONCLUSIONS

These data indicates oral anticoagulation use has improved in atrial fibrillation patients with stroke in Beijing. The use of anticoagulation among the patients from tertiary hospitals is significantly better than those from nontertiary hospitals, and the history of heart failure may have effect on the use of oral anticoagulation.

Formation of iodinated trihalomethanes during UV/chloramination with iodate as the iodine source

Iodinated trihalomethanes (I-THMs) are a group of emerging disinfection by-products with high toxicity, and iodide (I(-)) as well as iodinated organic compounds are expected to be their iodine sources. Nevertheless, in this study, iodate (IO3(-)) was proven to be a new iodine source of I-THM formation during UV/chloramination. In the iodate-containing waters (without any other iodine sources), I-THM formation increased with the increase of UV dose, IO3(-) and NH2Cl concentrations. With the increase of Br(-)/IO3(-) molar ratio, I-THM formation (especially for the brominated species) increased. Besides, NOM species could affect I-THM formation from IO3(-) during UV/chloramination. Fulvic acid could promote IO3(-) phototransformation to I(-) but humic acid impeded the production of I(-) during UV irradiation. Under realistic drinking water treatment conditions (DOC = 5.0 mg-C/L, IO3(-) = 12.7 μg-I/L, UV dose = 50 mJ/cm(2), NH2Cl = 5 mg-Cl2/L), CHCl2I was detected as 0.17 μg/L using solid-phase microextraction method, and the production rate of I-THMs from IO3(-) was about 7% of that from I(-).

Pyrroloquinoline quinone enhances the resistance to oxidative stress and extends lifespan upon DAF-16 and SKN-1 activities in C. elegans

Pyrroloquinoline quinone (PQQ) is linked to fundamental biological processes such as mitochondrial biogenesis and lipid metabolism. PQQ may also function as an essential micronutrient during animal development. Recent studies have shown the therapeutic potential of PQQ for several age-related diseases due to its antioxidant capacity. However, whether PQQ can promote longevity is unknown. Here, we investigate the effects of PQQ on oxidative stress resistance as well as lifespan modulation in Caenorhabditis elegans. We find that PQQ enhances resistance to oxidative stress and extends the lifespan of C. elegans at optimal doses. The underlying molecular mechanism involves the increased activities of the primary lifespan extension transcriptional factors DAF-16/FOXO, the conserved oxidative stress-responsive transcription factor SKN-1/Nrf2, and upregulation of daf-16, skn-1 downstream targets including sod-3, hsp16.2, gst-1 and gst-10. Our findings uncover a novel role of PQQ in longevity, supporting PQQ as a possible dietary supplement for overall health improvement.

Effect of UV irradiation on the proportion of organic chloramines in total chlorine in subsequent chlorination

This study investigated the changes of chlorine species and proportion of organic chloramines during the chlorination process after UV irradiation pretreatment in drinking water. It was found that the UV pretreatment could enhance the percentage of organic chloramines by increasing free chlorine consumption in the chlorination of raw waters. The percentage of organic chloramines in total chlorine increased with UV intensity and irradiation time in raw waters. However, for the humic acid synthesized water, the percentage of organic chloramines increased first and then decreased with the increase of UV irradiation time. The value of SUVA declined in both raw and humic acid synthesized waters over the UV irradiation time, which indicated that the decomposition of aromatic organic matter by UV could be a contributor to the increase of free chlorine consumption and organic chloramine proportion. The percentage of organic chloramines during chlorination of raw waters after 30-min UV irradiation pretreatment varied from 20.2% to 41.8%. Total chlorine decreased obviously with the increase of nitrate concentration, but the percentage of organic chloramines increased and was linearly correlated to nitrate concentration.

[Effect of prostate peripheral zones stromal cells on the proliferation of prostate cells by overexpression of LMO2 gene]

OBJECTIVE

To explore the biological effect of prostate peripheral zones (PZs) stromal cells on the proliferation of prostate cells by overexpression of LMO2 gene.

METHODS

Genes expressional distinction of different prostate stromal cells was screened by gene expression arrays. To validate the microarray data, real time-polymerase chain reaction (RT-PCR), Western blotting analysis were used to check the over expression of LMO2 in PZs cells.To compare the effect of stromal cells which overexpressed LMO2 gene on in vitro proliferation ability of BPH-1 and PC3 cell lines, cell proliferation was measured by CCK-8 and EdU assay. Cytokines chip was used to screen expression of cytokines in WPMY-1-LMO2 conditioned medium. The changes of BPH-1 and PC3 proliferation associated proteins were assessed by Western blotting.

RESULTS

A total of 512 genes were identified as markedly differentially expressed in stromal cells originated from different zones. Among these genes, LMO2 gene was overexpression in peripheral zones stromal cells, and confirmed by RT-PCR and Western blotting. Expression level of LMO2 gene was significantly up-regulated in peripheral zones stromal cells compared with transitional zones stromal cells, increased by 3.36 folds on average (P<0.01). The proliferation of both PC3 and BPH-1 were found increased and STAT3 phosphorylation and CCND1 expression were increased after cultured in conditioned medium from stromal cells which stably expressed LMO2. Cytokines chip found increased FGF-9 and IL-11 expression in the medium supernatant reserved from LMO2-overexpressed stromal cell line.

CONCLUSIONS

Distinct gene expression exists among prostate stromal cells originated from different zones. LMO2 overexpressed stromal cells can induce prostate epithelial cell growth via paracrine of FGF-9, IL-11 or other cytokines.

[Composition of NOM in raw water of Danjiangkou Reservoir of South-to-North Water Diversion Project and comparison of efficacy of enhanced coagulation]

The best enhanced coagulation conditions for the raw water of Danjiangkou Reservoir of South-to-North Water Diversion Project and the molecular weights as well as hydrophobicity composition of Natural organic matter (NOM) in the water were investigated in this study. The results showed that the NOM in the raw water of Danjiangkou Reservoir of South-to-North Water Diversion Project was mainly composed of the fraction with a molecular weight of < 1 000 and transphilic components. Dissolved organic carbon (DOC, 39.98%) and UV254 (39.10%) were the major components. And the fraction with a molecular weight of < 1 000 had the highest contents of THMFP and N-DBPFP. In the raw water of Danjiangkou Reservoir, the sum of transphilic and hydrophobic fractions was up to 80%, and the hydrophobic fraction was the minimum contributor of the NOM, but the THMFP of the hydrophobic fraction had the highest percentage. And when the raw water of Danjiangkou Reservoir was treated using polymeric ferric sulfate (PFS, 4 mg x L(-1)) and poly-acrylamide (PAM, 0.4 mg x L(-1)) , the optimal removal rates of turbidity, DOC, UV254 and THMFP were 76.33%, 25.57%, 37.78% and 23.16%, respectively. The results of this paper can provide theoretical and technological basis for upgrading of the process and operation optimization of original drinking water treatment plants in the intake area of South-to-North Water Diversion Project.

Comparison of iodinated trihalomethanes formation during aqueous chlor(am)ination of different iodinated X-ray contrast media compounds in the presence of natural organic matter

Iodinated trihalomethanes (I-THMs) formation during chlorination and chloramination of five iodinated X-ray contrast media (ICM) compounds (iopamidol, iopromide, iodixanol, histodenz, and diatrizoate) in the presence of natural organic matter (NOM) was evaluated and compared. Chlorination and chloramination of ICM in the absence of NOM yielded only a trace amount of I-THMs, while levels of I-THMs were enhanced substantially in raw water samples. With the presence of NOM, the order with respect to the maximum yield of I-THMs observed during chlorination was iopamidol >> histodenz > iodixanol > diatrizoate > iopromide. During chloramination, I-THM formation was enhanced for hisodenz, iodixanol, diatrizoate, and iopromide. The order with respect to the maximum yield of I-THMs observed during chloramination was iopamidol > diatrizoate > iodixanol > histodenz > iopromide. With the exception of iopamidol, I-THM formation was favored at relatively low chlorine doses (≤100 μM) during ICM chlorination, and significant suppression was observed with high chlorine doses applied (＞100 μM). However, during chloramination, increasing monochloramine dose monotonously increased the yield of I-THMs for the five ICM. During chlorination of iodixanol, histodenz, and diatrizoate, the yields of I-THMs exhibited three distinct trends as the pH increased from 5 to 9, while peak I-THM formation was found at circumneutral pH for chloramination. Increasing bromide concentration not only considerably enhanced the yield of I-THMs but also shifted the I-THMs towards bromine-containing ones and increased the formation of higher bromine-incorporated species (e.g., CHBrClI and CHBr2I), especially in chloramination. These results are of particular interest to understand I-THM formation mechanisms during chlorination and chloramination of waters containing ICM.

Degradation kinetics and chloropicrin formation during aqueous chlorination of dinoseb

The kinetics of chlorination of dinoseb and the corresponding formation of disinfection by-products (DBPs) were studied between pH 4 and 9 at room temperature (25±1°C). The reactivity shows a minimum at pH 9, a maximum at pH 4 and a medium at neutral conditions. pH profile of the apparent second-order rate constant of the reaction of dinoseb with chlorine was modeled considering the elementary reactions of HOCl with dinoseb species and an acid-catalyzed reaction. The predominant reactions at near neutral pH were the reactions of HOCl with the two species of dinoseb. The rate constants of 2.0 (±0.8)×10(4)M(-2)s(-1), 3.3 (±0.6) and 0.5 (±0.1)M(-1)s(-1) were determined for the acid-catalyzed reaction, HOCl reacted with dinoseb and dinoseb(-), respectively. The main degradation by-products of the dinoseb formed during chlorination have been separated and identified by GC-MS with liquid-liquid extraction sample pretreatment. Six volatile and semi-volatile DBPs were identified in the chlorination products, including chloroform (CF), monochloroacetone, chloropicrin (TCNM), 1,1-dichloro-2-methy-butane, 1,2-dichloro-2-methy-butane, 1-chloro-3-methy-pentanone. A proposed degradation pathway of dinoseb during chlorination was then given. TCNM and CF formation potential during chlorination of dinoseb reached as high as 0.077 and 0.097μMμM(-1) dinoseb under the traditional condition (pH=7 and Cl2/C=2). Their yields varied with Cl2/C, pH and time. The maximum yields of TCNM appeared at molar ratio as Cl2/C=1 and pH 3, while the maximum of CF appeared at molar ratio as Cl2/C=4 and pH 7. [TCNM]/[CF] decreased with reaction time and increased solution pH.

Formation of iodinated disinfection by-products during oxidation of iodide-containing water with potassium permanganate

This study shows that iodinated disinfection by-products (I-DBPs) including iodoform (IF), iodoacetic acid (IAA) and triiodoacetic acid (TIAA) can be produced when iodide-containing waters are in contact with potassium permanganate. IF was found as the major I-DBP species during the oxidation. Iodide was oxidized to HOI, I(2) and I(3)(-), consequently, which led to the formation of iodinated organic compounds. I-DBPs varied with reaction time, solution pH, initial concentrations of iodide and potassium permanganate. Yields of IF, IAA and TIAA increased with reaction time and considerable I-DBPs were formed within 12 h. Peak IF yields were found at circumneutral pH range. However, formation of IAA and TIAA was favored under acidic conditions. Molar ratio of iodide to potassium permanganate showed significant influence on formation of IF, IAA and TIAA. The formation of IF, IAA and TIAA also depended on the characteristics of the waters.

Degradation kinetics and N-Nitrosodimethylamine formation during monochloramination of chlortoluron

The degradation of chlortoluron by monochloramination was investigated in the pH range of 4-9. The degradation kinetics can be well described by a second-order kinetic model, first-order in monochloramine (NH(2)Cl) and first-order in chlortoluron. NH(2)Cl was found not to be very reactive with chlortoluron, and the apparent rate constants in the studied conditions were 2.5-66.3M(-1)h(-1). The apparent rate constants were determined to be maximum at pH 6, minimum at pH 4 and medium at alkaline conditions. The main disinfection by-products (DBPs) formed after chlortoluron monochloramination were identified by ultra performance liquid chromatography-ESI-MS and GC-electron capture detector. N-Nitrosodimethylamine (NDMA) and 5 volatile chlorination DBPs including chloroform (CF), dichloroacetonitrile, 1,1-dichloropropanone, 1,1,1-trichloropropanone and trichloronitromethane were identified. The distributions of DBPs formed at different solution pH were quite distinct. Concentrations of NDMA and CF were high at pH 7-9, where NH(2)Cl was the main disinfectant in the solution. NDMA formation during chlortoluron monochloramination with the presence of nitrogenous salts increased in the order of nitrite<nitrate<ammonium for a given monochloramination and chlortoluron concentration.

[Chlorination byproducts formation potentials of typical nitrogenous organic compounds in water]

Twelve typical nitrogenous organic compounds including herbicides, pesticides, amino acids, industrial products etc in polluted raw water were selected to investigate formation of typical carbonaceous and nitrogenous DBPs during chlorination and chloramination. To indentify the formation mechanism of carbonaceous and nitrogenous disinfection byproducts from nitrogenous chemicals, chlorination and chloroamination of urea herbicides, triazine herbicides, amino acid, and other compounds were investigated. As a result, the potential precursors for different DBPs were defined as well. It has been identified that widely used urea herbicides could produce as many as 9 specific DBPs. The chlorotoluron shows highest reactivity and yields chloroform (CF), monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), 1,1-dichloro-acetone (1,1-DCP), 1,1,1-trichloro-acetone (1,1,1-TCP), chloropicrin (NTCM), dichloro-acetonitrile (DCAN), dimethylnitrosamine (NDMA). The results indicated that aldicarb and dinoseb are important precursors of CF, DCAA, MCAA, NTCM as well. High concentrations of CF and DCAA were found during L-tryptophan chlorination. Furthermore, DBPs formation pathways and mechanisms were suggested during chlorination and chloramination of chlorotoluron, ametryn, dinoseb L-tryptophan.

Chlorination of chlortoluron: kinetics, pathways and chloroform formation

Chlortoluron chlorination is studied in the pH range of 3-10 at 25 ± 1°C. The chlorination kinetics can be well described by a second-order kinetics model, first-order in chlorine and first-order in chlortoluron. The apparent rate constants were determined and found to be minimum at pH 6, maximum at pH 3 and medium at alkaline conditions. The rate constant of each predominant elementary reactions (i.e., the acid-catalyzed reaction of chlortoluron with HOCl, the reaction of chlortoluron with HOCl and the reaction of chlortoluron with OCl(-)) was calculated as 3.12 (± 0.10)×10(7)M(-2)h(-1), 3.11 (±0.39)×10(2)M(-1)h(-1) and 3.06 (±0.47)×10(3)M(-1)h(-1), respectively. The main chlortoluron chlorination by-products were identified by gas chromatography-mass spectrometry (GC-MS) with purge-and-trap pretreatment, ultra-performance liquid chromatography-electrospray ionization-MS and GC-electron capture detector. Six volatile disinfection by-products were identified including chloroform (CF), dichloroacetonitrile, 1,1-dichloropropanone, 1,1,1-trichloropropanone, dichloronitromethane and trichloronitromethane. Degradation pathways of chlortoluron chlorination were then proposed. High concentrations of CF were generated during chlortoluron chlorination, with maximum CF yield at circumneutral pH range in solution.

Measurement of dissolved organic nitrogen in a drinking water treatment plant: size fraction, fate, and relation to water quality parameters

This paper investigates the characteristics of dissolved organic nitrogen (DON) in raw water from the Huangpu River and also in water undergoing treatment in the full-scale Yangshupu drinking water treatment plant (YDWTP) in Shanghai, China. The average DON concentration of the raw water was 0.34 mg/L, which comprised a relatively small portion (~5%) of the mass of total dissolved nitrogen (TDN). The molecular weight (MW) distribution of dissolved organic matter (DOM) was divided into five groups: >30, 10-30, 3-10, 1-3 and <1 kDa using a series of ultrafiltration membranes. Dissolved organic carbon (DOC), UV absorbance at wavelength of 254 nm (UV254) and DON of each MW fraction were analyzed. DON showed a similar fraction distribution as DOC and UV254. The <1 kDa fraction dominated the composition of DON, DOC and UV254 as well as the major N-nitrosodimethylamine formation potential (NDMAFP) in the raw water. However, this DON fraction cannot be effectively removed in the treatment line at the YDWTP including pre-ozonation, clarification and sand filtration processes. The results from linear regression analysis showed that DON is moderately correlated to DOC, UV254 and trihalomethane formation potential (FP), and strongly correlated to haloacetic acids FP and NDMAFP. Therefore, DON could serve as a surrogate parameter to evaluate the reactivity of DOM and disinfection by-products FP.

Measurements of dissolved organic nitrogen (DON) in water samples with nanofiltration pretreatment

Dissolved organic nitrogen (DON) measurements for water samples with a high dissolved inorganic nitrogen (DIN, including nitrite, nitrate and ammonia) to total dissolved nitrogen (TDN) ratio using traditional methods are inaccurate due to the cumulative analytical errors of independently measured nitrogen species (TDN and DIN). In this study, we present a nanofiltration (NF) pretreatment to increase the accuracy and precision of DON measurements by selectively concentrating DON while passing through DIN species in water samples to reduce the DIN/TDN ratio. Three commercial NF membranes (NF90, NF270 and HL) were tested. The rejection efficiency of finished water from the Yangshupu drinking water treatment plant (YDWTP) is 12%, 31%, 8% of nitrate, 26%, 28%, 23% of ammonia, 77%, 78%, 82% of DOC (dissolved organic carbon), and 83%, 87% 88% of UV(254) for HL, NF90 and NF270, respectively. NF270 showed the best performance due to its high DIN permeability and DON retention (∼80%). NF270 can lower the DIN/TDN ratio from around 1 to less than 0.6 mg N/mg N, and satisfactory DOC recoveries as well as DON measurements in synthetic water samples were obtained using optimized operating parameters. Compared to the available dialysis pretreatment method, the NF pretreatment method shows a similar improved performance for DON measurement for aqueous samples and can save at least 20 h of operating time and a large volume of deionized water, which is beneficial for laboratories involved in DON analysis. DON concentration in the effluent of different treatment processes at the YDWTP and the SDWTP (Shijiuyang DWTP) in China were investigated with and without NF pretreatment; the results showed that DON with NF pretreatment and DOC both gradually decreased after each water treatment process at both treatment plants. The advanced water treatment line, including biological pretreatment, clarification, sand filtration, ozone-BAC processes at the SDWTP showed greater efficiency of DON removal from 0.37 to 0.11 mg N L(-1) than that at the YDWTP, including pre-ozonation, clarification and sand filtration processes from 0.18 to 0.11 mg N L(-1).

Thulium: YAG 2 mum cw laser prostatectomy: where do we stand?

INTRODUCTION

Tm:YAG 2 mum cw laser prostatectomy was introduced in the treatment of benign ptostatic obstruction (BPO). Since then numerous studies have been published proving efficacy during follow-up. However, different surgical techniques were introduced with different names for similar techniques that complicate comparison. This reviews aim was to compare published data and break down surgical techniques to core points. The authors define validate appellations for different surgical techniques and propose further use of these names to ensure homogenous nomenclature.

MATERIALS AND METHODS

All publications on Thulium:YAG prostatectomy have been included in this review. Articles were reviewed and associated due to the nature of the surgical approach. A systematic review of published data was performed.

RESULTS

Sixteen peer-reviewed publications dealing with Tm:YAG laser prostatectomy were printed since 2005. Four different surgical principles are described, including vaporization, resection and enucleation. Follow-up, up to 24 months, showed durable functional results.

CONCLUSION

Efficacy of Tm:YAG prostatectomy was shown. Surgical techniques include "Tm:YAG Vaporization of the prostate (ThuVAP)", "Tm:YAG VapoResection of the prostate (ThuVaRP)" and "Tm:YAG VapoEnucleation of the prostate (ThuVEP)". The almost blunt enucleation is introduced as "Tm:YAG laser enucleation of the prostate (ThuLEP)". The authors recommend the use of this neologism in the future. Further, large-scale prospective studies are needed to prove long-term durability. To initiate and canalize these upcoming studies, the Urothulium Study Group was founded, combining international experts on Thulium:YAG laser prostatectomy under its roof.

[Pilot study on pentavalent arsenic removal by coagulation and the strengthening effect of flocs recycling]

The pilot and bench scale studies on pentavalent arsenic removal by coagulation and the strengthening effect of flocs recycling were performed. The results show that above 95% As (V) in the raw water exists in the form of dissolved As (V). Furthermore, the removal efficiencies of dissolved arsenic and total arsenic by mixing, first flocculation, second flocculation, sedimentation, filtration units were 87.92%, 6.18%, 2.38%, 1.55%, 1.23% and 1.10%, 1.83%, 2.20%, 86.42%, 7.38% respectively. Therefore, conversion rate of dissolved As(V) into particulate As(V) and the settlement performance of flocs were strongly dependent on the coagulation effect, which determined the As(V) removal efficiency in the whole system. Flocs have a strong adsorption capacity for As(V) and the adsorption obeys a second order reaction kinetics and well fits the modified Freundlich model. Flocs recycling can obviously promoted the As(V) removal by enhanced coagulation and reduce the dosage of coagulant with recycling point set at rapid mixed site and recycling ratio at 50%.

Oxidative degradation of dimethyl phthalate (DMP) by UV/H(2)O(2) process

The photochemical degradation of dimethyl phthalate (DMP) in UV/H(2)O(2) advanced oxidation process was studied and a kinetic model based on the elementary reactions involved was developed in this paper. Relatively slow DMP degradation was observed during UV radiation, while DMP was not oxidized by H(2)O(2) alone. In contrast, the combined UV/H(2)O(2) process could effectively degraded DMP, which is attributed to the strong oxidation strength of hydroxyl radical produced. Results show that DMP degradation rate was affected by H(2)O(2) concentration, intensity of UV radiation, initial DMP concentration, and solution pH. A kinetic model without the pseudo-steady state assumption was established according to the generally accepted elementary reactions in UV/H(2)O(2) advanced oxidation process. The rate constant for the reaction between DMP and hydroxyl radical was found to be 4.0 x 10(9) M(-1)s(-1) through fitting the experimental data to this model. The kinetic model could adequately describe the influence of key factors on DMP degradation rate in UV/H(2)O(2) advanced oxidation process, and could serve as a guide in designing treatment systems for DMP removal.

Specific targeting of prostate cancer cells in vitro by the suicide gene/prodrug system, uracil phosphoribosyltransferase/5-fluorouracil, under the control of prostate-specific membrane antigen promoter/enhancer

This study was designed to investigate the prostate cancer-specific tumoricidal effect of the suicide gene, Escherichia coli uracil phosphoribosyltransferase (UPRT), driven by the human prostate-specific membrane antigen promoter/enhancer (PSMA(E/P)) in vitro. When transfected with PSMA(E/P)-EGFP (enhanced green fluorescence protein) (a plasmid construct with the green fluorescence protein gene driven by the PSMA(E/P)), only the androgen-responsive and PSMA-positive prostate cancer cell line, LNCaP, expressed GFP, indicating the specificity of the PSMA(E/P) activity in androgen-sensitive and PSMA-positive prostate cancer cells. Taking advantage of this prostate cancer-specific property of PSMA(E/P), we successfully introduced bacterial UPRT into LNCaP cells where the tumoricidal effect of 5-fluorouracil (5-FU) was significantly increased when compared with the cells without the exogenous UPRT. We conclude that the efficacy of 5-FU-based chemotherapy in prostate cancers can be significantly improved by targeted expression of the suicide gene UPRT under the control of PSMA(E/P).

Photochemical degradation of diethyl phthalate with UV/H2O2

The decomposition of diethyl phthalate (DEP) in water using UV-H2O2 process was investigated in this paper. DEP cannot be effectively removed by UV radiation and H2O2 oxidation alone, while UV-H2O2 combination process proved to be effective and could degrade this compound completely. With initial concentration about 1.0mg/L, more than 98.6% of DEP can be removed at time of 60 min under intensity of UV radiation of 133.9 microW/cm2 and H2O2 dosage of 20mg/L. The effects of applied H2O2 dose, UV radiation intensity, water temperature and initial concentration of DEP on the degradation of DEP have been examined in this study. Degradation mechanisms of DEP with hydroxyl radicals oxidation also have been discussed. Removal rate of DEP was sensitive to the operational parameters. A simple kinetic model is proposed which confirms to pseudo-first order reaction. There is a linear relationship between rate constant k and UV intensity and H2O2 concentration.

Drinking water production by ultrafiltration of Songhuajiang River with PAC adsorption

In recent years, membrane ultrafiltration (UF) of surface water for drinking water treatment has become a more attractive technology worldwide as a possible alternative treatment to conventional clarification. To evaluate the performance of ultrafiltration membranes for treatment of surface water in North China, a 48-m2 low pressure hollow fiber membrane ultrafiltration pilot plant was constructed. Ultrafiltration was operated in cross-flow and with powdered activated carbon (PAC) adsorption. Turbidity was almost completely removed to less than 0.2 NTU (below Chinese standard 1 NTU). It was found that PAC addition enhanced organic matter removal. The combined process of PAC/UF allowed to 41% removal of COD(Mn), 46% removal of DOC and 57% decrease in UV254 absorbance. The elimination of particles, from average 12000/ml in the raw water to approximately 15/ml in the permeated, was observed. When PAC concentration was below 30 mg/L, backwashing could recovery the membrane flux with backwash interval/backwashing duration of 1/30.

Current Knowledge and Attitudes About Organ Donation and Transplantation Among Chinese University Students

Current attitudes toward organ donation among university students in mainland China and the differences in attitudes between Chinese students in mainland China versus overseas are unknown. To address these issues, we conducted a cross-sectional survey using questionnaires among 922 Chinese undergraduates from mainland China and overseas regions of the world. Data were analyzed by descriptive statistics, Student t tests, chi-square tests, and a logistic regression analysis. We found that blood donors showed significantly better awareness of heart, liver, lung, skin, and tendon donation among commonly transplanted organs/tissues. As to the willingness for cadaveric organ donation, 61.3% of respondents consented, 8.5% objected, and 30.3% answered "not sure." The percentage holding an organ donor card was 15.7% among students from Hong Kong; 3.0%, mainland China; 2.8%, Macau; 2.6%, Taiwan, and 4.0%, other regions of the world. In a logistic regression analysis, female students (odds ratio [OR], 2.24; 95% confidence interval [CI], 1.35 to 3.72) and blood donors (OR, 1.91; 95% CI, 1.10 to 3.32) did, but age and study specialty (medical vs nonmedical) did not show significantly more positive attitudes toward cadaveric organ donation. Compared with students from mainland China, overseas Chinese students from various regions did not show significantly different attitudes toward cadaveric organ donation. In summary, blood donors among university students have a greater knowledge of transplantation and a more positive attitude toward organ donation. Since university students are an important source of blood donors in China, they will be a potential pool of organ donors in the future.

[Effectiveness and mechanism of permanganate enhancing arsenite co-precipitation with ferric chloride]

The effectiveness and mechanism of permanganate enhancing arsenite (As(III)) co-precipitation with ferric chloride is investigated. Effects of parameters such as pH, natural organic matter (NOM) on As removal are studied. Permanganate significantly enhances As(III) removal for ferric co-precipitation (FCP) process. With Fe(III) dosage increasing from 2mg/L to 8mg/L, As removal increased from 41.3% to 75.4% for FCP process; for permanganate oxidation-ferric co-precipitation (POFCP) process, however, corresponsive As removal increased from 61.2% to 99.3% . As removal increased with higher pH for both processes; comparing to FCP process, pH had less effects on As removal for POFCP process; the presence of NOM reduced As removal for FCP process whereas no obvious reduction was observed for POFCP process. Permanganate oxidizing As(III) to As(V) is the main course for enhancing As(III ) removal; furthermore, products of permanganate reduction, hydrous MnO2 (s), also contribute to removing As. POFCP process exhibits good potential of removing As(III ) to assure chemical safety of drinking water.

Androgen receptor isoforms in human prostatic cancer tissue and LNCaP cell line

AIM

To investigate the androgen receptor (AR) isoform expressions in human prostatic cancer tissue and LNCaP cell line.

METHODS

With high resolution isoelectric focusing (IEF) method we demonstrated the different expressions of AR isoforms in human prostatic cancer tissues and LNCaP cell line.

RESULTS

Data were obtained from three prostatic cancer specimens and the LNCaP cell line. Three types of AR isoforms were detected with pI values at 6.5, 6.0, and 5.3. For the 3 prostatic cancer specimens, 1 sample showed all the three types of AR isoforms, the second specimen expressed at 6.5 and 6.0, and the third failed to show any type of isoforms. The LNCaP cell line expressed all the three AR isoforms. Binding of 3H-dihydrotestosterone (3H-DHT) to these three isoforms was inhibited by the addition of 100-fold excess of DHT or testosterone, while not by progesterone, oestradiol and diethylstilboestrol.

CONCLUSION

The expression of AR isoforms is different in different prostate cancer tissues, which may be related to the difference in the effect of anti-androgen therapy in different patients.

Apoptosis and hormonal milieu in ductal system of normal prostate and benign prostatic hyperplasia

AIM

To study the apoptotic rate (AR) and the androgen and estrogen milieu in the proximal and distal ductal systems of prostate, in order to help exploring the effects of these factors on prostatic growth and the pathogenesis of benign prostatic hypertrophy (BPH).

METHODS

The proximal and distal ends of the ductal system were incised from 20 normal prostate as well as the hypertrophic prostate tissue from 20 patients with BPH. The AR was determined by the DNA end-labeling method and dihydrotestosterone (DHT) and estrodiol (E2), by radioimmunoassay.

RESULTS

There was no significant difference in DHT and E2 density between the proximal and distal ends of the ductal systems in normal prostate. E2 appeared to be higher in BPH than in normal prostatic tissues, but the difference was statistically insignificant. In normal prostatic tissue, the AR was significantly higher in the distal than in the proximal ends of the ductal system (P < 0.05), while the AR of the proximal ends was significantly higher (P < 0.01) than that in the BPH tissue. No significant correlation was noted between the DHT and E2 density and the AR both in the normal prostate and BPH tissues.

CONCLUSION

The paper is the first time describing a difference in AR in different regions of the ductal system of normal prostate, while the hormonal milieu is similar, indicating a functional inhomogeneity of these regions. A low AR in the proximal duct, where BPH originates, and an even lower AR in the BPH tissue, suggesting the participation of apoptosis in the BPH pathogenesis.

Androgen receptor isoforms in human and rat prostate

AIM

To investigate the androgen receptor (AR) isoforms and its variability of expression in human and rat prostatic tissues.

METHODS

Human benign prostatic hyperplasia (BPH) and prostatic cancer tissues were obtained from patients undergoing prostatectomy, and rat ventral prostate was incised 3 days after castration. Forty-one AR-positive BPH specimens, 3 prostatic cancer specimens, and 6 rat prostates were used. After processing at 4 degrees C, the tissues were examined by means of high resolution isoelectric focusing (IEF) technique to determine their AR isoforms.

RESULTS

From the prostatic specimens, 3 types of AR isoforms were detected with pI values at 6.5, 6.0, and 5.3. In human BPH tissues, 15/41 (36.6%) specimens showed all the three types of isoforms, while 19/41 (46.3%) showed 2 isoforms at various combinations and 7/41 (17.1%), 1 isoform. For the 3 prostatic cancer specimens, one showed 3 isoforms, one, 2 isoforms, and the other failed to show any isoform. All rat prostatic tissues showed 2 isoforms at different combinations. Binding of 3H-dihydrotestosterone (DHT) to the isoforms was inhibited by the addition of 100-fold excess of DHT or testosterone, but not progesterone, oestradiol or diethylstilboestrol.

CONCLUSION

AR isoforms are different in different patients. Although their genesis is not clear, the therapeutic implication of the present observation appears to be interesting, that may help clarifying the individual differences in the response to hormonal therapy.

Elevated recombination in immortal human cells is mediated by HsRAD51 recombinase

Normal diploid cells have a limited replicative potential in culture, with progressively increasing interdivision time. Rarely, cell lines arise which can divide indefinitely; like tumor cells, such "immortal" lines display frequent chromosomal aberrations which may reflect high rates of recombination. Recombination frequencies within a plasmid substrate were 3.5-fold higher in nine immortal human cell lines than in six untransformed cell strains. Expression of HsRAD51, a human homolog of the yeast RAD51 and Escherichia coli recA recombinase genes, was 4.5-fold higher in immortal cell lines than in mortal cells. Stable transformation of human fibroblasts with simian virus 40 large T antigen prior to cell immortalization increased both chromosomal recombination and the level of HsRAD51 transcripts by two- to fivefold. T-antigen induction of recombination was efficiently blocked by introduction of HsRAD51 antisense (but not control) oligonucleotides spanning the initiation codon, implying that HsRAD51 expression mediates augmented recombination. Since p53 binds and inactivates HsRAD51, T-antigen-p53 association may block such inactivation and liberate HsRAD51. Upregulation of HsRAD51 transcripts in T-antigen-transformed and other immortal cells suggests that recombinase activation can also occur at the RNA level and may facilitate cell transformation to immortality.

Induction of duplication reversion in human fibroblasts, by wild-type and mutated SV40 T antigen, covaries with the ability to induce host DNA synthesis

Intrachromosomal homologous recombination, manifest as reversion of a 14-kbp duplication in the hypoxanthine phosphoribosyl transferase (HPRT) gene, is elevated in human cells either stably transformed or transiently transfected by the SV40 (simian virus 40) large T antigen gene. Following introduction of wild-type SV40, or any of several T-antigen point mutations in a constant SV40 background, we observed a strong correlation between the stimulation of chromosomal recombination and induction of host-cell DNA synthesis. Moreover, inhibitors of DNA replication (aphidicolin and hydroxyurea) suppress SV40-induced homologous recombination to the extent that they suppress DNA synthesis. Stable integration of plasmids encoding T antigen also augments homologous recombination, which is suppressed by aphidicolin. We infer that the mechanism by which T antigen stimulates homologous recombination in human fibroblasts involves DNA replicative synthesis.