[Clinical value of prostate specific antigen screening in early detection of prostate cancer].

OBJECTIVE: To evaluate the clinical significance of prostate-specific antigen (PSA) screening in early detection of prostate cancer in Chinese men. METHODS: PSA screening was performed in 8562 asymptomatic men who had been enrolled for health checkup and all were > or = 50 years old. Prostate biopsy was recommended for those with a serum PSA level > or = 4.0 ng/ml. The pathological and clinical features of the patients with prostate cancer detected by the PSA screening were compared with that of 82 clinically diagnosed prostate cancer patients during the same period. RESULTS: Of the 8562 asymptomatic men, 719 had PSA levels > or = 4.0 ng/ml and biopsy was performed in 295 of them. Fifty-eight prostate cancers were detected. The biopsy rate was 41.0% and positive detection rate was 19.7%. The overall age distribution in the screening group and the clinical groups was not significantly different (P = 0.176). However, 41.4% (24/58) of the patients in screening group were > 75 years old, and significantly more than that in the clinical group (25.6%, P = 0.0491). The proportion of the patients with PSA levels > or = 20 ng/ml in the screening group was significantly less than that in the patients of the clinical group (44.8% vs. 75.6%, P = 0.0002). Whether in the patients whose age was > 75 years old (P < 0.05) or < or = 75 years old (P = 0.0002), the patients in the screening group had significantly lower Gleason scores < 7 (60.3% vs. 34.1%, P = 0.002), more T1 or T2 tumor (87.9% vs. 26.8%, P < 0.0001) and more chance to receive radical prostatectomy (50.0% vs. 18.3%, P < 0.0001) than the patients in the clinical group did. However, the distributions of PSA levels at diagnosis and biopsy Gleason scores were not significantly different between the above mentioned two groups (P > 0.05). CONCLUSION: Prostate-specific antigen (PSA) screening is useful for early detection of prostate cancer in Chinese men aged > or = 50 years. The patients detected by PSA screening usually show a lower PSA level, Gleason scores and early clinical stage disease, and have more chance for radical prostatectomy than the clinically diagnosed patients.

[Correlation of prostate cancer susceptibility with genetic polymorphism of cytochrome P450 2E1, smoking and drinking: a case-control study in the population of Nanjing area].

OBJECTIVE: To investigate the association of the risk of prostate cancer (PCa) with the polymorphism of the CYP2E1 gene, smoking and drinking, and to explore the joint role of genes and living habits in PCa pathogenesis. METHODS: We conducted a case-control study on 109 PCa patients and 202 age-matched non-PCa male controls, and detected the polymorphisms of CYP2E1 Rsa I and Pst I sites by PCR-RFLP using DNA from peripheral blood lymphocytes. RESULTS: The history of deep smoking (OR = 2.29, 95% CI: 1.28 - 4.09) or heavy smoking (OR = 1.81, 95% CI: 1.02 - 3.22) was a risk factor. The CYP2E1 C1/C1 genotype significantly increased the risk of PCa (OR = 1.71, 95% CI: 1.04 - 2.82) and apparently interacted with drinking (OR = 2.21, 95% CI: 1.06 - 4.59). Heavy smokers with the C1/C1 genotype showed an increased risk of PCa (OR = 2.80, 95% CI: 1.20 - 6.56), as compared with non-smokers carrying the genotype of C1/C2 or C2/C2. CONCLUSION: The risk of PCa obviously increases in individuals with both the CYP2E1 C1/C1 genotype and the habit of smoking or drinking, and it has a significant positive correlation with the dose of tobacco exposure.

Molecular mechanism of epididymal protease inhibitor modulating the liquefaction of human semen.

AIM: To study the molecular mechanism of epididymal protease inhibitor (Eppin) modulating the process of prostate specific antigen (PSA) digesting semenogelin (Sg). METHODS: Human Sg cDNA (nucleotides 82-849) and Eppin cDNA (nucleotides 70-723) were generated by polymerase chain reaction (PCR) and cloned into pET-100D/TOPO. Recombinant Eppin and Sg (rEppin and rSg) were produced by BL21 (DE3). The association of Eppin with Sg was studied by far-western immunoblot and radioautography. In vitro the digestion of rSg by PSA in the presence or absence of rEppin was studied. The effect of anti-Q20E (N-terminal) and C-terminal of Eppin on Eppin-Sg binding was monitored. RESULTS: Eppin binds Sg on the surface of human spermatozoa with the C-terminal of Eppin (amino acids 75-133). rSg was digested with PSA and many low molecular weight fragments were produced. When rEppin is bound to rSg, then digested by PSA, incomplete digestion and a 15-kDa fragment results. Antibody binding to the N-terminal of rEppin did not affect rSg digestion. Addition of antibodies to the C-terminal of rEppin inhibited the modulating effect of rEppin. CONCLUSION: Eppin protects a 15-kDa fragment of rSg from hydrolysis by PSA.

[Persistent Müllerian duct syndrome: a report of 2 cases and review of the literature].

OBJECTIVE: To study the etiopathogenesis, clinical manifestations, diagnosis and management of persistent Müllerian duct syndrome (PMDS). METHODS: Two cases of PMDS were reported, one accompanied by transverse testicular ectopia and the other associated with cryptorchidism. Corporeal hysterectomy and orchidopexy were given to both the patients and cryptorchidectory the latter. RESULTS: Vascular supply and texture of the testis were normal in both the 2 patients after 1.5-2 years' follow-up. CONCLUSION: PMDS is male pseudohermaphroditism, for which means should be taken to preserve the blood supply and fertility function of the testis in surgical management, and attention should be paid to possible development of testis tumor in follow-up.

[Voltage-dependent anion channels (VDAC) on human sperm membrane].

OBJECTIVE: To further study gene expression and characterization of voltage-dependent anion channels (VDACs) on human spermatozoa. METHODS: VDACs were cloned by PCR from the testis cDNA library. Recombinant human sperm VDACs were produced in E. coli system by molecular cloning technology. Sperm membrane protein was extracted by 1% Triton X-100 and separated by chloroform/methanol. RESULTS: The gene expression of VDACs was found in the human testis cDNA library and VDAC protein was detected located on the sperm membrane by alpha-helix. CONCLUSION: VDAC proteins, abundant on the human sperm membrane and responsible for anion transportation, play an important role in sperm signaling transduction and fertility.

[Establishment of a mouse model of hypospadias induced by estradiol benzoate].

OBJECTIVE: To establish a mouse model of hypospadias induced by benzoate estradiol to further the studies on the molecular mechanisms of hypospadias. METHODS: A total of pregnant mice were randomly divided into 5 groups, Group A, B, C, D and E, and injected subcutaneously (sc) with estradiol benzoate at the dose of 0, 0.2, 1, 5 and 25 mg x kg(-1) d(-1) respectively from the 12th to the 16th gestational day. The mortality of the newborn mice was recorded and the male neonates of 2 pregnant mice from each group were anatomized to observe the testis position and prostate agenesis on the delivery day. Examinations were made for urethra and cryptorchidism on the 28th postnatal day. RESULTS: The death rates of the neonates in Group A, B, C, D and E were 21.6%, 21.5%, 41.4%, 56. 6% and 75.0%, respectively. Hypospadias was detected in Group C (3.3%, 1/30), D (20.0%, 4/20) and E (23.0%, 3/13), with significant difference between Group D and A (P < 0.05) and E and A (P < 0.05), but not between Group D and E (P > 0.05). Cryptorchidism was found in Group C (6.6%, 2/30) , D (30.0%, 6/20) and E (61.6%, 8/13), with significant difference between Group D and A (P < 0.05) and E and A (P < 0.05) , but not between Group D and E (P >0.05). CONCLUSION: Exposure of pregnant mice to large dose of estradiol benzoate can induce hypospadias and cryptorchidism in their neonates. And the right dose of estradiol benzoate for the establishment of the mouse model of hypospadias should be 5 mg x kg(-1) x d(-1).

[Procaryotic expression, purification and identification of recombinant human prostate-specific antigen].

OBJECTIVE: To produce recombinant human prostate-specific antigen (PSA) by molecular cloning technology and to identify its activity. METHODS: The human PSA cDNA and PET-12a vector were digested by NdeI and BamH1 before ligated by T4 ligase. The correct sequence was verified and transformed into high competent E. coli BL21 (DE3). Recombinant PSA was expressed and purified by hydrophobic interaction phenyl Sepharose column and activated by trypsin digestion. Enzymatic activation assay was done by hydrolysis of the substrate S-2586 and semenogelin. RESULTS: Non-active recombinant PSA was digested by trypsin and demonstrated enzyme activity. The activated PSA hydrolyzed S-2586 and its physiological substrate semenogelin (Sg). CONCLUSION: Recombinant pro-PSA can be an active serine protease by trypsin digestion and demonstrate native PSA enzymatic activity.

Genetic polymorphisms in the cytochrome P450 1A1 and 2E1 genes, smoking, drinking and prostate cancer susceptibility: a case-control study in a Han nationality population in Southern China.

AIM: To investigate the association among the polymorphisms of the cytochrome P450 1A1 and 2E1 genes, smoking, drinking and the risk of prostate cancer (PCa) in a Han nationality population in Southern China. METHODS: A case-control study including 225 PCa patients and 250 age-matched controls was conducted. The six polymorphic sites of the CYP 1A1 and CYP2E1 genes were analysed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) or allele-specific PCR technique using genomic DNA isolated from peripheral blood lymphocytes. RESULTS: We found that the CYP1A1 Val/Val genotype significantly increased the risk for PCa (OR, 2.26; 95% CI, 1.09-4.68). In contrast, the CYP2E1 C1/C2 (OR, 0.67; 95% CI, 0.46-0.99) or C2/C2 genotype (OR, 0.31; 95% CI, 0.10-1.00) significantly decreased the risk. Furthermore, the individuals carrying the CYP1A1 Val allele and the CYP2E1 C1/C1 genotype showed the highest risk (OR, 2.50; 95% CI, 1.45-4.29). Though there was no significant difference with smoking history (P = 0.237) or drinking habit (P = 0.499) between cases and controls, a deep smoking habit (OR, 2.02; 95% CI, 1.28-3.17) and heavy smoking history (OR, 1.61; 95% CI, 1.04-2.50) significantly increased the susceptibility of PCa after stratification by smoking method and accumulative smoking amount. Moreover, both the CYP1A1 Val allele (OR, 2.82; 95% CI, 1.49-5.35) and CYP2E1 C1/C1 genotype (OR, 2.57; 95% CI, 1.31-5.02) had obvious interaction with heavy smoking history that significantly raised the risk. We also discovered a significant interaction between the CYP2E1 C1/C1 genotype and drinking (OR, 1.85; 95% CI, 1.04-3.28). CONCLUSIONS: Individuals carrying the CYP1A1 Val allele or the CYP2E1 C1/C1 genotype with a smoking or drinking habit were at increased risk of PCa, which also showed a positive correlation with exposure dose of tobacco.

[Correlation of epididymal protease inhibitor Eppin and Semenogelin on human ejaculated spermatozoa].

OBJECTIVE: To evaluate the correlation of epididymal protease inhibitor(Eppin) and Semenogelin(Sg) on human ejaculated spermatozoa. METHODS: The experimental approaches include: (1) Immunoprecipitation of Eppin with anti-Eppin from semen; (2) Colocalization of Eppin and Sg by immunofluorescence; (3) Immunoprecipitation of rEppin and rSg;(4) Far-Western blotting of rEppin and rSg;(5) Competition of saturated 125I-rSg binding to rEppin with unlabeled Sg, and direct binding of 125I-rSg to rEppin on a blot; (6) Autoradiography of 125I-rSg with rEppin. RESULTS: Eppin-Sg complex present on the surface of human ejaculated spermatozoa, Cys-239 is the only cystein for rEppin binding rSg. Reduction and carboxymethylation of Cys-239 blocks binding of 125I-rEppin to rSg. CONCLUSION: Our study demonstrates that Eppin and Sg bind to each other on human ejaculated spermatozoa. A disulfide linkage occurs between Sg and Eppin, indicating the specificity of binding.

Polymorphisms of metabolic enzyme genes, living habits and prostate cancer susceptibility.

In this report, genetic polymorphism of phase I and II metabolic enzyme (CYP2E1, CYP17, GSTM1 and GSTT1) genes, living habits, and risk of prostate cancer (PCa) was studied in 163 patients with prostate carcinoma of Han nationality in Southern China and 202 age-matched controls. The genotypic polymorphism of CYP2E1, CYP17, GSTM1 and GSTT1 genes was analyzed by PCR-RFLP assay using genomic DNA isolated from peripheral blood lymphocytes. The significant risk factors for PCa included long-term exposure to toxicant (OR=2.27, 95%CI: 1.26-4.09), the tumor history of lineal consanguinity (OR=2.19, 95%CI: 1.30-3.67), sexual history before age 30 of no more than 8 times per month (OR=1.85, 95%CI: 1.22-2.81), deep inhalation of cigarette smoke (OR=2.01, 95%CI: 1.20-3.37) or heavy smoking (OR=1.67,95%CI: 1.01-2.76). Among individuals with long-term heavy smoking without tea-drinking habit, the risk increased significantly (OR=4.27, 95%CI: 1.62-11.24 and OR), 2.76, 95%CI: 1.20-6.32). CYP2E1 C1/C1 genotype significantly increased the risk for PCa (OR=1.61, 95%CI: 1.04-2.49) with an apparent interaction with alcohol (OR=2.07, 95%CI: 1.07-4.00). However, stratification by the amount of accumulative smoking revealed that among people with a heavy smoking history, the individuals with the CYP2E1 C1/C1 genotype (OR=2.55, 95%CI: 1.20-5.43) and the individuals with GSTT1 null genotype (OR=2.23, 95%CI: 1.09-4.57) showed a significantly increased risk. Any other significant results with GSTM1 or CYP17 genes were not observed in this research. Individuals with more sensitive genotypes (from one to four) were at an increased risk. The data show that, in the development of PCa, there are many interactions among predisposing genotypes and genetic polymorphisms and unhealthy living habits. Individuals with more susceptible genotypes and unhealthy habits such as prolonged exposure to smoking are at an increased risk.

Increased expressions of vascular endothelial growth factor (VEGF), VEGF-C and VEGF receptor-3 in prostate cancer tissue are associated with tumor progression.

AIM: To investigate the differences in microvessel densities (MVD) and the expressions of vascular endothelial growth factor (VEGF), VEGF-C and VEGF receptor-3 (VEGFR-3) between prostate cancer (PCa) tissues and adjacent benign tissues, and to explore the correlations among MVD, Jewett-Whitmore staging, Gleason scores and expressions of VEGF, VEGF-C and VEGFR-3 in the progression of PCa. METHODS: An immunohistochemical approach was adopted to detect the expressions of CD34, VEGF, VEGF-C and VEGFR-3 in both cancer areas and peripheral benign areas of 71 primary prostatic adenocarcinoma specimens. A statistic analysis was then performed according to the experimental and clinic data. RESULTS: Significantly upregulated expressions of VEGF, VEGF-C and VEGFR-3 were all found in malignant epithelium/cancer cells compared with adjacent benign epithelium (P<0.01). Patients in stage D had a significantly higher score than patients in stage A, B or C when comparing the expression of VEGF-C or VEGFR-3 in the tumor area (P<0.01). In addition, significant correlations were observed between Jewett-Whitmore staging and VEGF-C (r(s)=0.738, P<0.01), clinical staging and VEGFR-3 (r(s)=0.410, P<0.01), VEGF-C and Gleason scores (r(s)=0.401, P<0.01), VEGFR-3 and Gleason scores (r(s)=0.581, P<0.001) and MVD and VEGF (r(s)=0.492, P<0.001). CONCLUSION: Increased expressions of VEGF and VEGF-C were closely associated with progression of PCa. The main contribution of increased VEGF expression for PCa progression was to upregulate MVD, which maintained the growth advantage of tumor tissue. However, the chief role of increased expressions of VEGF-C and VEGFR-3 was to enhance lymphangiogenesis and provide a main pathway for cancer cells to disseminate.

[High intensity focused ultrasound combined with endocrine therapy in treating prostate cancer].

OBJECTIVE: To evaluate the clinical efficacy of high intensity focused ultrasound (HIFU) combined with endocrine therapy in the treatment of patients with prostate cancer. METHODS: Twenty patients with prostate cancer were treated with extracorporeal HIFU device( model FEP-BY01 ) and androgen ablation, of whom 15 received orchiectomy and 5 LHRH-a. Fourteen patients of the total number were given flutamide in addition to castration. RESULTS: The mean follow-up was 13.5 months (ranging 6 to approximately 30). Before and after the treatment, the prostate volume, prostate specific antigen (PSA), international prostate symptom score (IPSS) and maximal flow rate (Qmax) of the patients were (36.4 +/- 16.2) ml and (20.6 +/- 11.8) ml (P < 0.05), (32.2 +/- 10.4) ng/ml and (2.4 +/- 0.8) ng/ml (P < 0.01), 20. 5 +/- 6.5 and 13.6 +/- 7.5 (P < 0.05), (10.6 +/- 6.3) ml/s and (14.2 +/- 4.6) ml/s (P < 0.05), respectively. Mild hematuria and pain were noted in 5 and 8 patients respectively, and 1 patient underwent internal urethrotomy with a cold knife because of urethral stricture. er, with minimal complications. CONCLUSION: HIFU combined with endocrine therapy is effective in the treatment of prostate canc-

Anemia in patients on combined androgen block therapy for prostate cancer.

AIM: To study the effect of combined androgen block therapy on hemoglobin and hematocrit values in patients with prostate cancer. METHODS: One hundred and thirty-six patients with adenocarcinoma of prostate were treated with combined androgen block (orchiectomy and flutamide 250 mg, tid). Complete blood counts were determined before and after 1, 2, 3, 6, 9 and 12 months of therapy. RESULTS: The hemoglobin and hematocrit levels declined significantly in all patients and at all the time points after treatment (P<0.05). CONCLUSION: Prostate cancer patients treated with combined androgen block would develop obvious anemia. Recombinant human erythropoietin can be used to treat patients with severe anemia.

Transplantation tolerance mediated by regulatory T cells in mice.

BACKGROUND: With potent suppressive effect on responder T cells, CD(4)(+)CD(25)(+) regulatory T (Treg) cells have become the focus of attention only recently and they may play an important role in transplantation tolerance. However, the mechanism of action is not clear. This study was designed to assess the possibility of using CD(4)(+)CD(25)(+) Treg cells to induce transplantation tolerance and to investigate their mechanism of action. METHODS: CD(4)(+)CD(25)(+) Treg cells were isolated using magnetic cell separation techniques. Mixed lymphocyte reactions were used to assess the ability of Treg cells to suppress effector T cells. Before skin transplantation, various numbers of CD(4)(+)CD(25)(+) Treg cells, which have been induced using complex skin antigens from the donor, were injected into the host mice either intraperitoneally [0.5 x 10(5), 1 x 10(5), 2 x 10(5), 3 x 10(5), 4 x 10(5), or 5 x 10(5)] or by injection through the tail vein [5 x 10(3), 1 x 10(4), 2 x 10(4), 5 x 10(4), 1 x 10(5), 2 x 10(5)]. Skin grafts from two different donor types were used to assess whether the induced Treg cells were antigen-specific. The survival time of the allografts were observed. Single photon emission computed tomography was also used to determine the distribution of Treg cells before and after transplantation. RESULTS: Treg cells have suppressive effect on mixed lymphocyte reactions. Grafts survived longer in mice receiving CD(4)(+)CD(25)(+) Treg cell injections than in control mice. There was a significant difference between groups receiving intraperitoneal injection of either 2 x 10(5) or 3 x 10(5) CD(4)(+)CD(25)(+) Treg cells and the control group (P < 0.05, respectively). Better results were achieved when Treg cells were injected via the tail vein than when injected intraperitoneally. The transplantation tolerance induced by CD(4)(+)CD(25)(+) Treg cells was donor-specific. Analysis of the localization of Treg cells revealed that Treg cells mainly migrated from the liver to the allografts and the spleen. CONCLUSIONS: CD(4)(+)CD(25)(+)Treg cells can induce donor-specific transplantation tolerance. Cell-to-cell contact may be the primary mechanism by which Treg cells act on effector T cells.

[Tamsulosin in the treatment of benign prostatic hyperplasia patients with acute urinary retention].

OBJECTIVE: To evaluate the clinical efficacy of alpha-1 A adrenoceptor antagonist (tamsulosin) in the treatment of benign prostatic hyperplasia (BPH) patients with acute urinary retention. METHODS: Seventy-two BPH patients with acute retention of urine were randomly divided into treatment group and control group of 36 patients each. All the patients were treated with indwelling catheter, oral antibiotics and the patients in treatment group tamsulosin 0.4 mg once a day for 3 days. The catheter was removed after 72 hours of treatment. RESULTS: After removal of the catheter, 44% (32/72) of patients voided successfully. The effect rates were 61% (22/36) in the tamsulosin treatment group and 28% (10/36) in the control group(P < 0.01). CONCLUSIONS: Treatment with tamsulosin was effective in raising the success rate of voiding without catheter after an episode of acute urinary retention. The efficacy of treatment was not influenced by the volume of prostate.

[Anemia in patients on combined androgen block therapy for prostate cancer].

OBJECTIVE: To study the effect of combined androgen block therapy on hemoglobin (Hb) and hematocrit value (Ht) in patients with prostate cancer. METHODS: One hundred and thirty-six patients with adenocarcinoma of the prostate were treated with combined androgen block (orchiectomy and flutamide 250 mg, Tid). Complete blood counts were detected before initiation and after 1, 2, 3, 6, 9 and 12 months of therapy. RESULTS: Hb level declined significantly in all patients from a mean baseline of (136 +/- 14) g/L to (126 +/- 16) g/L, (121 +/- 14) g/L, (120 +/- 15) g/L, (113 +/- 12) g/L, (121 +/- 13) g/L and (123 +/- 15) g/L at 1, 2, 3, 6, 9 and 12 months. Ht decreased from a mean baseline of 0.424 +/- 0.041 to 0.390 +/- 0.038, 0.381 +/- 0.042, 0.378 +/- 0.038, 0.366 +/- 0.041, 0.384 +/- 0.039 and 0.387 +/- 0.040. The differences between Hb, Ht before and after treatment were significant (P < 0.05). CONCLUSION: Patients with prostate cancer being treated with combined androgen block would develop a significant degree of anemia. Hemoglobin and hematocrit level should be monitored periodically. This kind of anemia can be treated by recombinant human erythropoietin.

[The effect of acute urinary retention on serum prostate specific antigen concentration].

OBJECTIVES: To study the effect of acute urinary retention on the serum prostate-specific antigen (PSA) concentration. METHODS: Blood samples from 34 benign prostatic hyperplasia (BPH) patients with acute urinary retention were drawn immediately before suprapubic cystomy and 48 hours after relief of urinary retention. Serum PSA concentrations were measured with radioimmunoassay. RESULTS: The mean serum PSA levels of BPH patients with acute urinary retention was (24.6 +/- 16.1) micrograms/L (range from 2.6 micrograms/L to 45.8 micrograms/L). Forty-eight hours after relief of urinary retention, the mean serum PSA levels declined to (9.4 +/- 6.3) micrograms/L (range from 1.7 micrograms/L to 16.6 micrograms/L). The difference was significant (P < 0.01). CONCLUSIONS: Acute urinary retention could dramatically increase the serum PSA value of patients with BPH. After relief of the urinary retention, the patients had a great than 50% decreased of PSA values.