[Temporal and Spatial Variation Characteristics and Source Analysis of Agricultural Non-point Source Pollution Load in Guangdong During the Past 20 Years].

The agricultural non-point source pollution (ANPSP) load in Guangdong province is very large and has a serious impact on the regional ecological environment. Inventory analysis was used to assess and analyze the temporal and spatial variation characteristics of the ANPSP load of Guangdong province during 1999-2019, and the sources of ANPSP were discussed, as well as the relationship between them. The results showed that, during the past 20 years, the total ANPSP pollution loads of Guangdong province decreased by 6.08%, and the pollution loads of chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) increased by -11.88%, 4.99%, and 26.17%, respectively. The input intensity of chemical fertilizers and pesticides increased by 112.19% and 60.38%, respectively. The Pearl River Delta had the highest ANPSP loads in Guangdong province, followed by those in northern, western, and eastern Guangdong. Livestock and poultry breeding were the main sources of COD, the total percent fertilizers and livestock and poultry breeding were the main sources of TN, and livestock and poultry breeding and aquaculture were the main sources of TP. In addition, the contribution of pollutants discharged from aquaculture showed an obvious increasing trend. There were certain differences in the pollution sources in different regions. In western Guangdong, northern Guangdong, and eastern Guangdong, livestock and poultry breeding were the main sources of COD and TP, and fertilizer was the main source of TN; by contrast in the Pearl River Delta, aquaculture had become the main source of TN and TP pollution loads. The correlation results showed that the decline in the total ANPSP in Guangdong province was mainly due to the increase in high urbanization rate and the decrease in the proportion of rural population. In general, there were stage changes in the time and differences in spatial characteristics and sources of ANPSP in Guangdong province. A combination of comprehensive treatment and targeted pollution treatment should be adopted, and fertilizer reduction measures and pollution treatment in the aquaculture should be strengthened in an all-around way, focusing on strengthening the treatment of pollution from aquaculture in the Pearl River Delta region and the treatment of rural life pollution in northern Guangdong.

Tropism and transduction of oncolytic adenovirus vectors in prostate cancer therapy.

Oncolytic adenovirus has been applied in cancer therapy because of several advantages such as cost-effective production, high transduction efficiency and low toxicity. Recent efforts have been focused on the modification of oncolytic adenovirus by encoding transgenes within the viral genome to efficiently and selectively replicate within cancer cells, destroy cancerous cells, induce tumor cell apoptosis, and stimulate the recruitment of immune cells to the tumor site. Nevertheless, there are still big challenges for translational research of oncolytic virotherapy in clinical cancer management. Therefore, here we summarize current status on the design and application of oncolytic adenovirus vectors for prostate cancer therapy. In particular, we describe the main receptors associated with the tropism and transduction of oncolytic adenovirus vectors, and propose new directions in future studies for prostate cancer virotherapy.

[Construction of an oncolytic adenovirus expressing small hairpin RNA and targeting the SATB1 gene].

OBJECTIVE: To construct an oncolytic adenovirus with the DD3 promoter regulation, expressing small hairpin RNA and targeting the SATB1 gene (SATBI-shRNA), and to evaluate its potential for inhibiting the growth of human prostatic carcinoma cells (LNCaP) in vitro. METHODS: SATB1-shRNA expression cassettes containing the H1 promoter were produced by PCR from pSilencer3. 1-SATB1 and inserted into the pZD55 vector, and the recombinant plasmid pZD55-SATB1-shRNA was constructed, pZD55SATB1-shRNA and pZXC2-DD3-E1A were digested with EcoRV and Xba I , and the obtained expression cassettes linked each other to construct the recombinant plasmid pDD3-ZD55-SATB1, which was cotransfected with the pBHGE3 packaging plasmids mixture into 293 cells by Effectence. The recombined adenoviruses DD3-ZD55-SATB1 were identified by PCR. Viruses were propagated on HEK293 cells and purified by standard techniques, and the functional PFU titers determined by plaque assay on 293 cells. The antitumor potential of DD3-ZD55-SATB1 to LNCaP was evaluated by the crystal violet dye method. The expression level of the E1A gene was detected by Western blot, and that of the SATB1 gene in the adenovirus-infected LNCaP cells by both Western blot and RT-PCR. RESULTS: An oncolytic adenovirus expressing SATB1-shRNA with the DD3 promoter regulation, DD3-ZD55-SATB1, was constructed successfully, whose functional PFU titer was 1.2 x 10(10) PFU/ml. DD3-ZD55-SATB1 showed an obvious cytopathic effect and a selective expression of E1A in the adenovirus-infected LNCaP cells; it exhibited a high LNCaP-targetability and specific SATB1-silencing effect. CONCLUSION: The successful construction of the oncolytic adenovirus DD3-ZD55-SATB1 offers a new tool for researches on the gene therapy for human prostate cancer.

[Skip metastasis of prostate cancer: diagnosis and treatment].

OBJECTIVE: To improve the diagnosis and treatment of far advanced prostate cancer without clinically detectable bone metastasis. METHODS: Cancer metastatic lesions were found in the liver and lungs respectively of two patients on routine medical examination, and only an abnormally elevated level of the serum prostate specific antigen (PSA) was observed in the following system examinations. The patients were diagnosed as having prostate cancer by prostate biopsy. MRI showed a discontinued prostate capsule, and ECT revealed no bone metastasis. Diagnostic treatment was conducted by giving LHRHa combined with antiandrogens. One of the patients underwent surgical castration at 12 months, and both received intensity modulated radiation therapy (80 Gy) at 15 and 18 months, respectively. RESULTS: The metastatic lesions in the liver and lungs of the patients were either absent or significantly reduced after treated by maximal androgen blockade for 3 months, and all disappeared after 6 months'treatment, with the PSA level stabilized at less than 0.02 microg/L in one patient, and around 0.5 microg/L in the other. Antiandrogen treatment was suspended after radiotherapy. The results of liver, lung and bone scanning were normal during the 12-month follow-up, and the PSA level was below 1.0 microg/L. CONCLUSION: Remote metastasis of prostate cancer may occur in ectosteal organs first, which deserves special attention. A combination of different treatment methods promises satisfactory results.

Inhibition of prostate cancer DU145 cell growth with small interfering RNA targeting the SATB1 gene.

Prostate cancer is a common visceral cancer of men worldwide. It is important to develop a more effective treatment for prostate cancer to overcome the treatment resistance that occurs with recurrence. RNA interference has been demonstrated to be a powerful tool for gene knockdown and has potential as a cancer treatment. It has been previously demonstrated that staining of special AT-rich sequence-binding protein 1 (SATB1) was stronger in prostatic carcinoma with metastasis compared with prostatic carcinoma without metastasis. In the present study, SATB1 small interfering (si)RNA was transfected into prostate cancer DU145 cells and normal human lung fibroblast cells, and cell proliferation was investigated using a Cell Counting kit-8. Three siRNA were transfected into cells using siPORT Lipid Transfection agent, and blank control and negative control groups were established. The cells were harvested and SATB1 mRNA and protein expression was determined by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. DU145 cell adhesion, migration and invasion capabilities were determined using cell adhesion, Transwell and Transwell with Matrigel assays, respectively. Silencing SATB1 significantly inhibited DU145 cell growth, adhesion, migration and invasive capability in vitro, indicating that a SATB1-targeting siRNA was successfully engineered. The results of the present study suggest that SATB1 siRNA may be a potential agent for treating human prostate cancer.

Inhibition of prostate cancer cell growth in vivo with short hairpin RNA targeting SATB1.

Despite previous advances, the treatment options for prostate cancer remain limited. For the purposes of gene knockdown, the utility of RNA interference has been demonstrated and is considered to have therapeutic potential. In the present study, a short hairpin RNA (shRNA) was used to assess the effect of special AT-rich sequence binding protein (SATB1) downregulation on the growth and metastatic potential of prostate cancer in xenograft nude mice. A plasmid carrying shRNA targeting SATB1, pSilencer-SATB1-shRNA, was successfully engineered. Using this plasmid, significant downregulation of SATB1 mRNA and protein expression in the DU145 prostate cancer cells was observed. pSilencer-SATB1-shRNA was demonstrated to be markedly efficacious against prostate cancer xenografts in nude mice. These results may lead to a novel method of improving gene therapy efficacy against prostate cancer via regulating the function of SATB1.

Knockdown of Ki-67 by small interfering RNA leads to inhibition of proliferation and induction of apoptosis in human renal carcinoma cells.

To investigate the effect of small-interfering RNA (siRNA) targeted against Ki-67, which is an attractive molecular target for cancer therapy, on inhibiting Ki-67 expression and cell proliferation in human renal carcinoma cells (HRCCs), siRNAs were used to inhibit the expression of Ki-67 in HRCCs. Ki-67 mRNA levels were detected by RT-PCR and in situ hybridization analysis. Ki-67 protein levels were detected by Western blot and immunocytochemistry analysis. TUNEL assay was used to measure the apoptosis of carcinoma cells. Results of RT-PCR and in situ hybridization demonstrated reduction of Ki-67 mRNA expression in Ki-67 siRNAs treated 786-0 cells. Similar reduction in Ki-67 protein measured by Western blot and immunocytochemistry was observed in cells transfected with Ki-67 siRNA. Ki-67-siRNA treatment of HRCCs resulted in specific inhibition of proliferation and increased apoptotic cell death. From these findings we conclude that inhibition of Ki-67 expression by siRNA may be a reasonable approach in renal cancer therapy.

[The value of pre-operative semen analysis as a restore index of fertilizing capacity after varicocelectomy].

OBJECTIVE: To discuss the value of pre-operative semen analysis of patients with varicocele as a predictive restore index of sperm motility and fertilizing capacity after varicocelectomy. METHODS: Semen analysis was carried out with computer-aided sperm analyzer in 107 patients with varicocele and all patients were referred to the clinic with diagnosis of male infertility. Stratification of patients as group A (n = 32), B ( n = 36) and C (n = 39) was based on pre-operative total motile sperm count (TMSC). Follow-up included semen analysis and pregnancy data after three months following left or bilateral varicocelectomy. RESULTS: The average post-operative TMSC increased significantly when compared with the pre-operative. However, a mean absolute increase in group A and B was better than that in group C (P < 0.05). Of the 68 patients in groups A and B based on pre-operative TMSC, 56 patients' TMSC (82.4%) was > or =20 x 10(6) after varicocelectomy, and that of only 8 (20.5%) patients in group C was > or =20 x 10(6) following varicocelectomy. Of the 98 patients wives, 36 had natural conception. Pregnancy rates in groups A and B were higher than that in group C (P < 0.05). CONCLUSION: Varicocelectomy may be the most effective method to patients with varicocele with pre-operative TMSC > or = 5 x 10(6), but it may be not the best method for patients with severe oligoasthenospermia (pre-operative TMSC < 5 x 10(6)).

[Association between polymorphism of CYP17 gene and serum hormone concentrations in aged men].

OBJECTIVE: To investigate the association between polymorphism of CYP17 gene and serum hormone concentrations in aged men. METHODS: Eighty-three healthy men at the average age of 66.7 were divided into a < 66.7 group (n = 36) and a > 66.7 group (n = 47), and the polymorphism of CYP17 gene in the 5' promoter region was investigated by PCR using DNA from the men's peripheral blood lymphocytes. A new recognition site was created for the restriction enzyme MspA1 I by transition (T --> C) in the risk allele (A2). Three genotypes A1/A1, A1/A2, A2/A2 were established, serum sex-hormone levels measured, and mean hormone concentration evaluated in each genotype and age group. RESULTS: No evidence was found that the testosterone (T) level, estrogen (E2) level and T/E2 ratio were associated with the genotype of CYP17 gene. There was no significant difference in T and E2 levels between the two groups, but there was a significant increase in the T/E2 ratio (P < 0.05). CONCLUSION: A2 allele does not increase sex hormone levels in aged men, but the T/E, ratio was higher in the > 66.7 group than in the < 66.7 group. This may be closely associated with the mechanism of benign prostate hyperplasia and prostate cancer in aged men.

[Root anatomical structure and hydraulic traits of three typical shrubs on the sandy lands of northern Shaanxi Province, China].

Root xylem anatomical structure and hydraulic traits of three typical shrubs, i.e., Salix psammophila, Caragana korshinskii and Hippophae rhamnoides, within two soil layers (0-20 cm and 30-50 cm) were compared. The results showed that S. psammophila had a higher leaf water potential than C. korshinskii and H. rhamnoides, the average maximum and minimum lumen diameter (d(max) and d(min), respectively), the average lumen area of vessels (Alum) and the ratio of lumen area of all vessels to xylem area (Aves/Axyl) in S. psammophila roots were also significantly higher than those in C. korshinskii and H. rhamnoides, and the root vessel density (VD) in S. psammophila was the same as that in H. rhamnoides but significantly higher than that in C. korshinskii. Root hydraulic conductivity in S. psammophila was 5 times of C. korshinskii and 2.8 times of H. hamnoides. The vulnerability index in S. psammophila roots was similar to that in C. korshinskii but higher than that in H. hamnoides. S. psammophila belonged to a water-spending species, whereas both C. korshinskii and H. rhamnoides were water-saving species, and C. korshinskii was more drought-resistant than H. rhamnoides. There was no difference of d(max), d(min) and Alum between roots in two soil layers, but roots within in the 30-50 cm soil layer had larger VD and Aves/Axyl. The root specific hydraulic conductivity within the 30-50 cm soil layer was significantly higher than within the surface soil layer, whereas the vulnerability index within the 30-50 cm soil layer was smaller, indicating roots in deep soil layers had higher hydraulic transport efficiency and lower hydraulic vulnerability.

[Hydraulic limitation on photosynthetic rate of old Populus simonii trees in sandy soil of north Shaanxi Province].

'Old and dwarf trees' on the loess plateau region mainly occurred among mature trees rather than among small trees. To elucidate the mechanism of tree age on 'old and dwarf trees' formation, taking Populus simonii, a tree species that accounted for the largest portion of 'old and dwarf trees' on the loess plateau, as an example, the growth, photosynthesis and hydraulic traits of P. simonii trees with different ages (young: 13-15 years, mid-aged: 31-34 years, and old: 49-54 years) were measured. The results showed that the dieback length increased, and net photosynthetic rate, stomatal conductance, transpiration rate, and whole plant hydraulic conductance decreased significantly with the increasing tree age. Both net photosynthetic rate and stomatal conductance measured at different dates were significantly and positively related to the whole plant hydraulic conductance, suggesting that the decreasing photosynthetic rate of old trees was possibly caused by the declined hydraulic conductance. Although the resistance to cavitation in stems and leaves was stronger in old trees than in young and mid-aged trees, there were no differences in midday native stem embolization degree and leaf hydraulic conductance based on the vulnerability curve estimation, suggesting that the increased hydraulic resistance of the soil-root system is probably the most important reason for decreasing the whole plant hydraulic conductance of old trees.

Retroperitoneoscopic renal pedicle lymphatic disconnection for chyluria in presence of complex renal vasculature.

OBJECTIVE: To evaluate retroperitoneoscopic renal pedicle lymphatic disconnection (RRPLD) for chyluria in the setting of complex renal vasculature and compare those outcomes with the RRPLD outcomes of patients with normal renal vasculature. MATERIALS AND METHODS: From December 2002 to December 2011, RRPLD was performed in 14 patients with complex renal vasculature and 64 patients with normal renal vasculature. Preoperative multislice spiral computed tomography angiography for renal vessels was done on 5 patients with complex vasculature. The demographic and perioperative data were collected to assess critical outcomes. RESULTS: The abnormal vasculature was identified using preoperative multislice spiral computed tomography angiography in 5 patients and surgical exploration in 9 patients. RRPLD was successfully completed in all patients without conversion to open surgery or vascular injury. The mean operative time was significantly longer in those with complex renal vasculature than those with normal renal vasculature (105.4 ± 18.7 vs 84.5 ± 15.6 minutes; P = .000). The outcomes were similar in the 2 groups in terms of intraoperative blood loss (P = .060), mean hospital stay (P = .478), and intraoperative complications (P = .660). The occurrence of postoperative gross hematuria was significantly greater in those with complex renal vasculature than in those with normal renal vasculature (4 of 14 vs 2 of 64; P = .008). The event was resolved uneventfully. CONCLUSION: Although it is technically challenging, RRPLD is feasible and safe for patients in the presence of complex renal vasculature. Preoperative evaluation of the renal vasculature with multislice spiral computed tomography angiography is beneficial for managing abnormal renal vessels.

Relationships among MTHFR a1298c gene polymorphisms and methylation status of Dact1 gene in transitional cell carcinomas.

OBJECTIVES: The purpose of this study was to determine the relationship between methylation status of the Dact1 gene and MTHFR a1298c polymorphic forms in transitional cell carcinoma tissues in a Chinese population. METHODS: Polymorphisms of folate metabolism enzyme gene MTHFR were assessed by restrictive fragment length polymorphism (RFLP) methods and PCR-based DNA methylation analysis was used to determine the CpG island methylation status of the Dact1 gene. Associations between the methylation status of the Dact1 gene and clinical characteristics, as well as MTHFR a1298c polymorphisms, were analyzed. RESULTS: aberrant methylation of the Dact1 gene was found in 68.3% of cancer tissues and 12.4% of normal tissues,. The methylation rate of the Dact1 gene in cancer tissues was significantly higher in patients with lymph node metastasis than in those without lymph node metastasis (46.3% vs. 17.2%, P = 0.018). No association was found between aberrant DNA methylation and selected factors including sex, age, tobacco smoking, alcohol consumption and green tea consumption. After adjusting for potential confounding variables, variant allele of MTHFR a1298c was found to be associated with methylation of the Dact1 gene. Compared with wild type CC, the odds ratio was 4.33 (95% CI: 1.06-10.59) for AC and 4.95 (95% CI: 1.18-12.74) for AA. The N stage in TNM staging and the occurrence of lymph node metastasis were associated with an MTHFR 1298 AAµAC genotype (P<0.05). CONCLUSION: MTHFR 1298 AC and AA genotypes might help maintain a normal methylation status of the Dact1 gene, aberrant CpG island methylation of which is closely related to the genesis and progression of transitional cell carcinoma.

Comparison of two approaches to retroperitoneoscopic renal pedicle lymphatic disconnection for chyluria.

BACKGROUND AND PURPOSE: The retroperitoneoscopic renal pedicle lymphatic disconnection has been performed mainly via a renal adipose (RA) capsule approach. In this study, we reported a novel technique via extra-adipose (EA) capsule approach and compared the two approaches for intractable chyluria. PATIENTS AND METHODS: From December 2002 to March 2008, retroperitoneoscopic renal pedicle lymphatic disconnection was performed on 41 patients with 23 EA and 18 RA. The stripping of hilar vessels and ureterolympholysis were performed in both approaches, while the mobilization of the kidney was only performed in RA. Comparisons of the two approaches were conducted, including mean operative time, intraoperative blood loss, postoperative bed rest, and hospital stay, as well as operative outcome. RESULTS: Patients were treated successfully without major complications. EA showed the same advantages as RA in terms of intraoperative blood loss (54.9±19.3 mL vs 59.3±26.5 mL, P>0.05), postoperative hospital stay (6.6±1.0 d vs 7.2±0.9 d, P>0.05). Chyluria disappeared in all patients immediately after the operations. EA was significantly superior to RA in operative time (78.9±18.3 min vs 101.8±20.6 min, P<0.05) and the postoperative bed rest time (20.7±1.7 h vs 72.0±0.0 h, P<0.05). No recurrence or nephroptosis was diagnosed in any patient within the follow-up of 21 to 84 months. CONCLUSIONS: Retroperitoneoscopic renal pedicle lymphatic disconnection for chyluria is safe and efficacious. EA offers significantly shorter operative time and earlier return to postoperative ambulation.

Treatment with vector-expressed small hairpin RNAs against Ki67 RNA-induced cell growth inhibition and apoptosis in human renal carcinoma cells.

Short hairpin RNAs (shRNAs) transcribed by RNA polymerase III promoters can trigger sequence-selective gene silencing in mammalian cells. By virtue of their excellent function in knocking down expression of cancer-associated genes, shRNAs could be used as new therapeutic agents for cancer. As overexpression of Ki67 in renal cancer has been correlated to a more aggressive tumor phenotype, inhibition of Ki67 protein expression by means of shRNAs seems to be a promising approach for the therapy of renal cancer. In this study, we constructed an expression plasmid encoding shRNAs against the Ki67 gene, named pSilencerKi67, and transfected it into human renal carcinoma cells. The pSilencerKi67 was shown to significantly knock down the expression of the Ki67 gene in human renal carcinoma cells, resulting in inhibiting proliferation and inducing apoptotic cell death that can be maintained for at least 6 d. These findings offer the promise of using vector-based shRNAs against Ki67 in renal cancer gene therapy.

Inhibition of proliferation and induction of apoptosis in human renal carcinoma cells by anti-telomerase small interfering RNAs.

Telomerase is an attractive molecular target for cancer therapy because it is present in most malignant cells but is undetectable in most normal somatic cells. Human telomerase consists of two subunits, an RNA component (hTR) and a human telomerase reverse transcriptase component (hTERT). Small interfering RNA (siRNA), one kind of RNA interferences, has been demonstrated to be an effective method to inhibit target gene expression in human cells. We investigated the effects of siRNA targeting at both hTR and hTERT mRNA on the inhibition of telomerase activity in human renal carcinoma cells (HRCCs). The proliferation and apoptosis of HRCCs were examined. The treatment of HRCCs using hTR and hTERT siRNAs resulted in significant decrease of hTR mRNA, hTERT mRNA and hTERT protein. The siRNA can also inhibit the telomerase activity and the proliferation of HRCCs. Moreover, they can induce apoptotic cell death in a dose-dependent manner. From these findings, we propose that the inhibition of telomerase activity using siRNA targeting hTR and hTERT might be a rational approach in renal cancer therapy.