Inactivation of PTEN is associated with increased angiogenesis and VEGF overexpression in gastric cancer

AIM: To investigate the expression of PTEN/MMAC1/TEP1 and vascular endothelial growth factor (VEGF), their roles in biologic behavior and angiogenesis and their association in gastric cancer.METHODS: Immunohistochemical staining was used to evaluate the expression of PTEN, VEGF and microvascular density (MVD) on paraffin-embedded sections in 70 patients with primary gastric cancer and 24 patients with chronic superficial gastritis (CSG). Expression of PTEN, VEGF and MVD were compared with clinicopathological features of gastric cancer. The relationship between expression of PTEN, VEGF and MVD as well as the relationship between PTEN and VEGF expression in caner cells were investigated. RESULTS: PTEN expression significantly decreased (t= 3.98, P<0.01) whereas both VEGF expression and MVD significant increased (t = 4.29 and 4.41, respectively, both P<0.01) in gastric cancer group compared with CSG group. PTEN expression was significantly down-regulated (t=1.95, P<0.05) whereas VEGF expression (t = 2.37, P<0.05) and MVD (t= 3.28, P<0.01) was significantly up-regulated in advanced gastric cancer compared with early-stage gastric cancer. PTEN expression in gastric cancer showed a negative association with lymph node metastasis (t= 3.91, P<0.01), invasion depth (t= 1.95, P<0.05) and age (t= 4.69, P<0.01). MVD in PTEN-negative gastric cancer was significantly higher than that in PTEN-positive gastric cancer (t=3.69, P<0.01), and there was a negative correlation betweenPTEN expression and MVD (γ=-0.363, P<0.05). VEGF expression was positively associated with invasion depth (especially with serosa invasion, t = 4.69, P<0.01), lymph node metastasis (t= 2.31, P<0.05) and TNM stage (t= 3.04, P<0.01). MVD in VEGF-positive gaslyic cancer was significantly higher than that in VEGF-negative gastric cancer (t=4.62, P<0.01), and there was a positive correlation between VEGF expression of and MVD (y = 0.512, P<0.05). VEGF expression in PTEN-negative gaslyic cancer was significantly stronger than that in PTEN-positive gastric cancer (t=2.61, P<0.05), and there was a significantly negative correlation between the expression of VEGF and PTEN (γ=-0.403, P<0.05).CONCLUSION: Our results imply that inactivation of PTEN gene and over-expression of VEGF contribute to the neovascularization and progression of gastric cancer. PTEN-related angiogenesis might be attributed to its up-regulation of VEGF expression. PTEN and VEGF could be used as the markers reflecting the biologic behaviors of tumor and viable targets in therapeutic approaches to inhibit angiogenesis of gastric cancers.

Male genital schwannoma, review of 5 cases

Aim: To study the clinical features of male genital schwannoma. Methods: Five male patients with genital schwannoma admitted from 1991 to 2000 were reviewed. The lesions were located in the prostate, spermatic cord, testis or penis. Tumors were simply resected in 3 patients and radically eradicated in 2. Results: The average age of the cohort was 37 years. The most common sign at presentation was a palpable genital mass accidentally discovered by the patient or detected by the physician during a physical check. Diagnosis was made through postoperative pathological examination. Follow-up ranged from 2 years to 6 years (mean 4.5 years). Four cases were cured by simple excision and 1 patient with malignant testis schwannoma died of recurrence 1 year after surgery. Conclusion: Owing to the lack of characteristic clinical manifestation, the final diagnosis relys on postoperative pathological examination. S-100 and vimentin are useful markers for the diagnosis of these tumors.

Early diagnosis of bacterial and fungal infection in chronic cholestatic hepatitis B

AIM: To investigate the early diagnostic methods of bacterial and fungal infection in patients with chronic cholestatic hepatitis B.METHODS: One hundred and one adult in-patients with chronic hepatitis B were studied and divided into 3 groups:direct bilirubin (DBil)/total bilirubin (TBil)≥0.5, without bacterial and fungal infection (group A, n=-38); DBil/TBil<0.5, without bacterial and fungal infection (group B, n=23),DBil/TBil≥0.5, with bacterial or fungal infection (group C,rr=-40). The serum biochemical index and pulse rate were analyzed.RESULTS: Level of TBil, DBil, alkaline phosphatase (ALP) and DBiI/ALP in group A increased compared with that in group B. The level of ALP in group C decreased compared with that in group A, whereas the level of TBil, DBil and DBiI/ALP increased (ALP: 156+43, 199+68, respectively,P<0.05, TBil: 370+227, 220+206, respectively, P<0.01,DBil: 214+143, 146+136, respectively, P<0.01, DBiI/ALP:1.65+1.05, 0.78+0.70, respectively, P<0.001). The level of DBil and infection affected DBiI/ALP. Independent of theeffect of DBil, infection caused DBiI/ALP to rise (P<0.05).The pulse rate in group A decreased compared with that in group B (63.7+6.4, 77.7+11.4, respectively, P<0.001),and the pulse rate in group C increased compared withthat in group A (81.2+12.2, 63.7+6.4, respectively, P<0.001).The equation (infection=0.218 pusle rate +1.064 DBiI/ALP-16.361), with total accuracy of 85.5%, was obtained from stepwise logistic regression. Pulse rate (≥80/min) andDBiI/ALP (≥1.0) were used to screen infection. The sensitivity was 62.5% and 64.7% respectively, and the specificity was 100% and 82.8% respectively.CONCLUSION: Bacterial and fungal infection deterioratejaundice and increase pulse rate, decrease serum ALP andincrease DBiI/ALP. Pulse rate, DBiI/ALP and the equation(infection=0.218 pusle rate+1.064 DBil/ALP-16.361) arehelpful to early diagnosis of bacterial and fungal infectionin patients with chronic cholestatic hepatitis B.

Folding and everting distal end of graft flap to reduce orifice stenosis following onlay urethroplasty

<abstract>Aim: Orifice stenosis remained to be a common complication of hypospadias repair. We had modified the preputial island flap urethroplasty by folding and everting the distal end of the pedicle graft flap to prevent the neoorifice from stenosis. Methods: Sixteen patients had undergone hypospadias repair using a modified onlay island flap technique. A urethral catheter was retained for 8 days to 10 days after operation. Results: Satisfactory results were seen in all the patients with a cosmetically fine appearance. One patient had a urinary tract infection and another, urethrocutaneous fistula and both were amply treated. No glanular adhesion or stenosis occurred. A long-term follow up of 6 months to 4 years (mean: 2 years) in 15 patients did not find any complication. Conclusion: The modified preputial island flap urethroplasty technique is an easy, reliable and effective approach to reduce orifice stenosis in hypospadias repair.

SELF-ADAPTIVE CONTROLS OF A COMPLEX CELLULAR SIGNALING TRANSDUCTION SYSTEM

In cells, the interactions of distinct signaling transduction pathways originating from cross-talkings between signaling molecules give rise to the formation of signaling transduction networks, which contributes to the changes (emergency) of kinetic behaviors of signaling system compared with single molecule or pathway. Depending on the known experimental data, we have constructed a model for complex cellular signaling transduction system, which is derived from signaling transduction of epidermal growth factor receptor in neuron. By the computational simulating methods, the self-adaptive controls of this system have been investigated. We find that this model exhibits a relatively stable selfadaptive system, especially to over-stimulation of agonist, and the amplitude and duration of signaling intermediates in it could be controlled by multiple self-adaptive effects, such as 'signal scattering', 'positive feedback', 'negative feedback' and 'B-Raf shunt'. Our results provide an approach to understanding the dynamic behaviors of complex biological systems.

POTENT DEGLYCOSYLATED RICIN A CHAIN IMMUNOTOXINS SPECIFICALLY KILLING OF XENOTROPIC MURINE RETROVIRUS-INFECTED CELLS

Immunotoxins (ITs) are conjugates between toxin and specific ligands, such as monoclonal antibodies (McAb) and growth factor, which may result in potent and specific killing of antigen positive cells. This approach was initially expected to create new cancer therapeutic reagents. Recently, however, the possibility of treating AIDS and other retrovirus-induced diseases with ITs has been realized, and several ITs directed against envelope glycoproteins of human immunodeficiency virus (HIV) have been constructed. Retroviruses have also been implicated as etiologic agents for autoimmune diseases in humans and animal models of systemic lupus erythematosus (SLE). The expression of an endogenous retroviral envelope glycoprotein and the production of autoantibodies reacting with this protein were found to correlate with the development of fatal glomerulonephritis and arteritis in lupus-prone strains of mice. To elucidate true roles of the endogenous retroviruses in animal models of autoimmune diseases the