Antitumor effects of human interferon-alpha 2b secreted by recombinant bacillus Calmette-Guérin vaccine on bladder cancer cells.

OBJECTIVE: Our objective was to construct a recombinant bacillus Calmette-Guérin vaccine (rBCG) that secretes human interferon-alpha 2b (IFNα-2b) and to study its immunogenicity and in vitro antitumor activity against human bladder cancer cell lines T24 and T5637. METHODS: The signal sequence BCG Ag85B and the gene IFNα-2b were amplified from the genome of BCG and human peripheral blood, respectively, by polymerase chain reaction (PCR). The two genes were cloned in Escherichia coli-BCG shuttle-vector pMV261 to obtain a new recombinant plasmid pMV261-Ag85B-IFNα-2b. BCG was transformed with the recombinant plasmid by electroporation and designated rBCG-IFNα-2b. Mononuclear cells were isolated from human peripheral blood (PBMCs) and stimulated with rBCG-IFNα-2b or wild type BCG for 3 d, and then cultured with human bladder cancer cell lines T24 and T5637. Their cytotoxicities were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: BCG was successfully transformed with the recombinant plasmid pMV261-Ag85B-IFNα-2b by electroporation and the recombinant BCG (rBCG-IFNα-2b) was capable of synthesizing and secreting cytokine IFNα-2b. PBMC proliferation was enhanced significantly by rBCG-IFNα-2b, and the cytotoxicity of PBMCs stimulated by rBCG-IFNα-2b to T24 and T5627 was significantly stronger in comparison to wild type BCG. CONCLUSIONS: A recombinant BCG, secreting human IFNα-2b (rBCG-IFNα-2b), was constructed successfully and was superior to control wild type BCG in inducing immune responses and enhancing cytotoxicity to human bladder cancer cell lines T24 and T5637. This suggests that rBCG-IFNα-2b could be a promising agent for bladder cancer patients in terms of possible reductions in both clinical dosage and side effects of BCG immunotherapy.

[Construction of recombinant bacillus Calmette-Guérin vaccine secreting human interferon-alpha 2b].

OBJECTIVE: To construct a recombinant bacillus Calmette-Guérin vaccine (rBCG) secreting human interferon-alpha 2b (IFN alpha-2b). METHODS: BCG Ag85B signal sequence and IFN alpha-2b gene were amplified from the genome of BCG and of human peripheral blood by polymerase chain reaction (PCR), respectively. IFN alpha-2b gene was cloned in E. coli-BCG shuttle-vector pMV261 to get pMV261-IFN alpha-2b. A new recombinant plasmid pMV261-IFN alpha-2b was constructed by inserting BCG Ag85B signal sequence into pMV261-Ag85B-IFN alpha-2b. Then, BCG was transformed with this recombinant plasmid by electroporation, and designated as rBCG-IFN alpha-2b. The DNA and protein expressions of IFN alpha-2b gene in rBCG were determined by PCR and Western blot respectively. Also the quantity of IFN alpha-2b protein secreted by rBCG in culture supernatants was determined by enzyme linked immunosorbent assay (ELISA). RESULTS: By partial nucleotide sequencing, the DNA sequences of human IFN alpha-2b and BCG Ag85B were consistent with that in the Gene Bank, and were correctly inserted into the shuttle expression vector pMV261 to construct recombinant plasmid pMV261-Ag85B-IFN alpha-2b. BCG was successfully transformed with this recombinant plasmid by electroporation and the recombinant BCG (rBCG-IFN alpha-2b) was capable of synthesizing and secreting cytokine IFN alpha-2b. The concentration of IFN alpha-2b in culture supernatants was quantified by ELISA and calculated to be approximately 301.45 pg/ml. CONCLUSIONS: Recombinant BCG secreting human IFN alpha-2b (rBCG-IFN alpha-2b) was constructed successfully and the specific IFN alpha-2b protein can be expressed highly and steadily by rBCG vaccine.

Poor visualization of renal collecting system in intravenous urography as an indicator of invasive transitional cell carcinoma in the upper urinary tract.

BACKGROUND: Transitional cell carcinoma of the upper urinary tract (UUT-TCC) accounts for 5% to 10% of all renal tumours and 5% to 6% of all urothelial tumours all over the world. In China, the proportion of UUT-TCC to all urothelial tumours may be 26%, which is higher than that in the western world. The early diagnosis of UUT-TCC is difficult and the present study elucidates the diagnostic value of poor or nonvisualization (PNV) in intravenous urography in patients with UUT-TCC and its correlations with pathological findings and clinical characteristics. METHODS: The data of 172 consecutive patients between January 1997 and January 2005 with UUT-TCC who underwent nephroureterectomy in our departments were selected and analyzed retrospectively. RESULTS: Of our sample, 144 cases presented with gross haematuria (83.7%) and 12 with microscopic haematuria (7.0%). Forty-six cases (26.7%) were detectable by cytology. Filling defect identified 36 positive cases of 172 patients (20.9%), PNV was present in the images of 105 of 172 patients (61.0%). The detection rate by PNV (61.0%) was significantly different from that by cytology (26.7%) or by filling defect (20.9%) (P = 0.031, P = 0.001, respectively). Univariate logistic regression analysis for PNV showed that tumour stage, grade and size were significant predictors (P = 0.028; P = 0.031; P = 0.006, respectively). Tumour stage and size were identified as independent risk factors in the multivariate logistic regression model (P = 0.042; P = 0.014). CONCLUSIONS: Except for suspected urolithiasis, urinary tuberculosis or congenital abnormalities, UUT-TCC should be considered if PNV exists in intravenous urography especially of old patients. The value of PNV is much more significant than filling defect in intravenous urography in the diagnosis of UUT-TCC. It is supposed that PNV carries more risk of higher stage and larger tumour size in UTT-TCC.

[Predictive factors for conversion of transurethral resection of the prostate to open prostatectomy].

OBJECTIVE: To evaluate the factors for the conversion of transurethral resection of the prostate (TURP) to open prostatectomy and to provide clinical evidence for surgical options. METHODS: From January 1997 to March 2005, we performed 1 086 TURP and made retrospective analyses of 11 risk factors concerning the demographics, clinical history, laboratory data, ultrasound results, and intraoperative complications of the patients. In addition, multivariate logistic regression was used to determine those variables predicting the conversion of TURP. RESULTS: Thirty-nine (3.59%) of the TURP cases required conversion, mostly because of uncontrollable hemorrhage (71.79%). Multivariate analyses showed that a prostate volume > 85.2 ml (OR = 2.568, P < 0.01), intraoperative slit of capsula prostatic (OR = 1.916, P < 0.01) and a second midstream bladder specimen (VB2) white blood cell count of the urine > 13.5/HP (OR = 1.486, P < 0.01) predicted the conversion to open prostatectomy. CONCLUSION: Benign prostatic hyperplasia (BPH) patients with a huge prostate and those with intraoperative slit of capsula prostatic undergoing TURP are more likely to be converted. And uncontrollable hemorrhage, huge prostate and poor endoscopic vision are the major reasons for the conversion.

Preventive effect of gelatinizedly-modified chitosan film on peritoneal adhesion of different types.

AIM: To comparatively study the preventive effect of gelatinizedly-modified chitosan film on peritoneal adhesions induced by four different factors in rats. METHODS: Chitosan was chemically modified by gelatinization, and made into films of 60 microm in thickness, and sterilized. Two hundred Sprague-Dawley rats were randomly divided into five groups, Sham-operation group (group A), wound-induced adhesion group (group B), purified talc-induced adhesion group (group C), vascular ligation-induced adhesion group (group D), and infection-induced adhesion group (group E), respectively. In each group, the rats were treated with different adhesion-inducing methods at the cecum of vermiform processes and then were divided into control and experimental subgroups. Serous membrane surface of vermiform processes were covered with the films in the experimental subgroups, and no films were used in the control subgroups. After 2 and 4 wk of treatments, the abdominal cavities were reopened and the adhesive severity was graded blindly according to Bhatia's method. The cecum of vermiform processes were resected for hydroxyproline (OHP) measurement and pathological examination. RESULTS: Adhesion severity and OHP level: After 2 and 4 wk of the treatments, in the experimental subgroups, the adhesions were significantly lighter and the OHP levels were significantly lower than those of the control subgroups in group B (2 wk: 0.199 +/- 0.026 vs 0.285 +/- 0.041 microg/mg pr, P < 0.001; 4 wk: 0.183 +/- 0.034 vs 0.276 +/- 0.03 microg/mg pr, P < 0.001), D (2 wk: 0.216 +/- 0.036 vs 0.274 +/- 0.040 microg/mg pr, P = 0.004; 4 wk: 0.211 +/- 0.044 vs 0.281 +/- 0.047 microg/mg pr, P = 0.003) and E (2 wk: 0.259 +/- 0.039 vs 0.371 +/- 0.040 microg/mg pr, P < 0.001; 4 wk: 0.242 +/- 0.045 vs 0.355 +/- 0.029 microg/mg pr, P < 0.001), but there were no significant differences in groups A (2 wk: 0.141 +/- 0.028 vs 0.137 +/- 0.026 microg/mg pr, P = 0.737; 4 wk: 0.132 +/- 0.031 vs 0.150 +/- 0.035 microg/mg pr, P = 0.225) and C (2 wk: 0.395 +/- 0.044 vs 0.378 +/- 0.043 microg/mg pr, P = 0.387; 4 wk: 0.370 +/- 0.032 vs 0.367 +/- 0.041 microg/mg pr, P = 0.853); Pathological changes: In group B, the main pathological changes were fibroplasias in the treated serous membrane surface and in group D, the fibroplasia was shown in the whole layer of the vermiform processes. In group E, the main pathological changes were acute and chronic suppurative inflammatory reactions. These changes were lighter in the experimental subgroups than those in the control subgroups in the three groups. In group C, the main changes were foreign body giant cell and granuloma reactions and fibroplasias in different degrees, with no apparent differences between the experimental and control subgroups. CONCLUSION: The gelatinizedly-modified chitosan film is effective on preventing peritoneal adhesions induced by wound, ischemia and infection, but the effect is not apparent in foreign body-induced adhesion.

Hepatic effects in workers exposed to 2-methoxy ethanol.

The objective of this study was to investigate the effects of 2-ME on hepatic function in exposed workers. Fifty-three impregnation workers from two copper-clad laminate-manufacturing factories using 2-ME as a solvent were recruited as the exposed group. Another group of 121 lamination workers with indirect exposure to 2-ME was recruited as the comparison group. Environmental monitoring of air 2-ME concentrations and biological monitoring of urine 2-methoxy acetic acid concentrations were performed. Venous blood was collected for blood biochemistry analyses. Liver function examination results showed that the aspartate amino transferase, alanine amino transferase, and gamma-glutamyl transferase in the 2-ME-exposed workers were not significantly different from those in the comparison workers. After adjustment for hepatitis carrier status, gender, body mass index, and duration of employment, no difference were found between exposed and comparison groups. We conclude that 2-ME was not a hepatotoxin.