Isolation, and morphological and chemical properties of an autolysis-deficient mutant of Clostridium botulinum type A

An autolysis-deficient mutant was isolated from Clostridium botulinum type A 190L by treatment with ethyl methanesulfonate. The cell wall prepared from the mutant autolyzed at much slower rate than that from the parent strain, accompanying with much less liberation of both amino terminals and reducing groups. Electron microscopic observation revealed that the mutant strain was converted to short rod or curved spherical form with thickened cell walls when the growth temperature was shifted from 37 to 45 C. The mutant had a significantly larger amount of non-peptidoglycan-carbohydrate complexes than did the parent strain and became markedly resistant to the autolysin partially purified from the parent, compared with the parent strain. Furthermore, the mutant was fairly tolerant to killing by penicillin. These results suggest that the autolysis deficiency of the mutant was due not only to the deficient production of autolysin but also to the excess accumulation of carbohydrate in the cell wall.

Detection of the c-myc gene product in urinary bladder cancer

Expression of the c-myc gene product in urinary bladder cancer was investigated by immunohistochemical staining with anti-c-myc monoclonal antibody (mAb) MYC-1. Positive staining was observed in the cytoplasm, but not in the nucleus in tissues fixed with 10% formalin. On the other hand, positive staining was localized in the nucleus in cryopreserved tissues. Of 34 cryopreserved specimens examined, positive staining with MYC-1 mAb was observed in 1 of 12 (8.3%) of grade 1 (G1), 12 of 15 (80%) of G2 and 6 of 7 (86%) of G3. Positive staining with Ki-67 mAb was observed in 2 of 12 (17%) of G1, 12 of 15 (80%) of G2, and 6 of 7 (86%) of G3. These results suggest that tumors with higher nuclear pleomorphism contain more proliferating cells.

[Production of monoclonal antibodies against human bladder cancer cells and application to immunohistochemical analysis of bladder cancer]

Two hybridomas secreting two monoclonal antibodies IgG1 B1.4 and IgG2a B1.6 were obtained by immunizing BALB/c mice with human bladder cancer cell line EJ-1. In immunohistochemical staining of cryopreserved tissues, B1.4 reacted with 0 of 9 grade 1 TCC, 6 of 11 grade 2, all of 6 grade 3 and five metastatic specimens. The antigen recognized by B1.4 was not expressed by normal urothelial cells but were expressed by vascular endothelial cells and muscle of tunica media. The target antigen of B1.6 was expressed by normal urothelial cells and all grade of TCC. In this study, it was demonstrated that poorly differentiated bladder cancer and metastatic specimens of bladder cancer express a vascular carbohydrate antigen. Taking the escape mechanism of immune surveillance, into consideration, it is possible that the antigen recognized by B1.4 is an indicator of metastatic potential of bladder cancer.

[Upper urinary tract tumors following bladder cancer]

We treated in total 795 patients with primary transitional cell carcinoma of the urinary bladder between April, 1964 and December, 1988. Eighteen patients of them had upper urothelial cancer during the follow-up period. Thirteen of the 18 patients had received transurethral resection for the initial bladder cancer, while 3 total cystectomy and 2 segmental resection. The over-all incidence of bladder cancer patients who subsequently developed upper urinary tract tumors was 2.3 per cent. The interval between initial treatment of the bladder cancer and treatment for the upper urinary tract tumor ranged from 2 to 74 months (median 20 months). The five-year survival rate after treatment for the upper urinary tract tumor was 31.7 per cent. We conclude that the following are high risk patients for development of upper urinary tract recurrences: 1) patients with bladder cancer near orifices, 2) patients with recurrent bladder cancer under bladder preserving treatment for a long time, 3) patients with G2 multifocal bladder cancer.

Nitro reaction in mice injected with pyrene during exposure to nitrogen dioxide

We have previously reported that the beta-glucuronidase-treated urine of mice injected intraperitoneally with pyrene during exposure to NO2 contained highly mutagenic compounds such as nitropyrene metabolites when tested by the Ames assay using Salmonella typhimurium strain TA98. In the present study, we found that the formation of these mutagens was dose-dependent between 10 and 200 mg of pyrene per kg of body weight at 5 and 10 ppm of NO2. Further, to elucidate the substrate of nitration in vivo, we injected 1-hydroxypyrene, which is the metabolite of pyrene, to mice intraperitoneally during exposure to NO2. Since the results were the same as those obtained by injection with pyrene, we suggest that the pyrene was not nitrated directly but after its hydroxylation.

Biliary excretion of glutathione conjugates of 4,5-epoxy-4,5-dihydro-1- nitropyrene and 9,10-epoxy-9,10-dihydro-1-nitropyrene in rats administered 1-nitropyrene orally and their further metabolism in the intestinal tract

1-Nitropyrene (1-NP), a mutagenic and carcinogenic substance that occurs in the environment, is metabolized by reductive and oxidative pathways. 4,5-Epoxy,4,5-dihydro-1-NP (1-NP 4,5-oxide) and 9,10-epoxy-9,10-dihydro-1-NP (1-NP 9,10-oxide) are oxidatively activated metabolites of 1-NP, and react with glutathione. HPLC analysis of biliary metabolites from rats administered [3H]1-NP orally showed the presence of glutathione conjugates of 1-NP 4,5-oxide and 1-NP 9,10-oxide and their metabolites, cysteinylglycine and cysteine conjugates. During the 48 h following [3H]1-NP administration, 21.4% of the biliary metabolites were excreted as glutathione, cysteinylglycine and cysteine conjugates of 1-NP oxides. The proportions of glutathione conjugates of 1-NP 4,5-oxide and 1-NP 9,10-oxide were 2.6 and 10.4% respectively. Bile and pancreatic juice collected from normal rats metabolized glutathione conjugates of 1-NP oxides and produced the corresponding cysteinylglycine and cysteine conjugates. In particular, the gamma-glutamyltransferase activity of pancreatic juice was markedly high. When glutathione conjugates of 1-NP oxides were incubated with a cell-free extract of small intestinal contents, they decreased rapidly and cysteine conjugates increased via cysteinylglycine conjugates, indicating that pancreatic juice plays an important role in the small intestine for the metabolism of glutathione conjugates to corresponding cysteine conjugates. Although degradation activity of small intestinal contents for cysteine conjugates was very low, degradation activity of the contents of the cecum and large intestine was high and was inhibited by an inhibitor of cysteine conjugate beta-lyase (beta-lyase) activity, aminooxyacetic acid. Furthermore, the intestinal anaerobic bacteria Peptostreptococcus magnus and Eubacterium limosum showed high beta-lyase activity, suggesting that the cysteine conjugates might be further metabolized by beta-lyase of the normal bacterial flora in the lower intestine to the reactivated metabolites and reabsorbed.

Mutagenicity of oxidized microsomal metabolites of 1-nitropyrene in Chinese hamster ovary cells

1-Nitropyrene, a tumorigenic environmental pollutant, is mutagenic in Chinese hamster ovary (CHO) cells in the presence of a liver homogenate 9000 g supernatant fraction (S9). The metabolic pathways involved in this response were studied by comparing the mutagenicities at the hypoxanthine-guanine phosphoribosyl transferase locus of 1-nitropyrene, some oxidized microsomal metabolites of 1-nitropyrene, and related compounds. In the absence of S9, pyrene 4,5-oxide and 6-hydroxy-1-nitropyrene displayed the highest mutagenicities, followed by 1-nitropyrene 9,10-oxide and 1-nitropyrene 4,5-oxide; 3- and 8-hydroxy-1-nitropyrene were weaker mutagens, while pyrene and 1-nitropyrene were essentially without activity. With S9, the order of mutagenic potency was 1-nitropyrene 4,5-oxide greater than 6-hydroxy-1-nitropyrene approximately 1-nitropyrene 9,10-oxide greater than 1-nitropyrene approximately 3-hydroxy-1-nitropyrene approximately 8-hydroxy-1-nitropyrene greater than pyrene approximately pyrene 4,5-oxide, with the latter two compounds being essentially inactive. Inclusion of the epoxide hydrolase inhibitor 1,2-epoxy-3,3,3-trichloropropane during the S9-mediated treatment of CHO cells with 1-nitropyrene increased mutation induction 5-fold. Also, liver microsomes prepared from guinea-pigs treated with Aroclor 1254 mediated a stronger mutagenic response with 1-nitropyrene than microsomes from Aroclor-treated rats. 1-Nitropyrene was essentially non-mutagenic in the presence of microsomes from untreated and phenobarbital-treated rats. Examination of the 1-nitropyrene metabolites produced during the microsomal incubations indicated that Aroclor-induced guinea-pig microsomes yielded substantial amounts of 1-nitropyrene 4,5-dihydrodiol, while Aroclor-induced rat microsomes produced 6-fold more 6- and 8-hydroxy-1-nitropyrene than phenobarbital microsomes.(ABSTRACT TRUNCATED AT 250 WORDS)

[VM-26 and VP-16 salvage therapy for refractory germinal testicular cancers]

Thirteen evaluable patients with germinal testicular cancers failing to be cured with first-line therapy (refractory) were treated by salvage chemotherapy. Ten patients received salvage chemotherapy with VM-26 (50 mg/m2, twice a week X 6 weeks) and cisplatin (CDDP, 20 mg/m2 for 5 consecutive days every 3 weeks for 3-4 times) (P-VM), 3 patients were also treated by radiation therapy, and 3 patients received VP-16 (100 mg/m2) and CDDP (20 mg/m2) (P-VP), all given daily for 5 consecutive days every 3-4 weeks for 4-5 courses. Of 13 evaluable patients, 6 (46%) had complete response (CR) (three cases were also treated with radiation therapy), 4 (31%) achieved partial response (PR), and 3 (23%) had no response. Limited to 7 patients treated with only P-VM therapy, there were 3 (43%) CR and 4 (57%) PR. Nine patients (69%) remained alive and were continuously disease free 18 to 84 months (median 48 months). Hematologic toxicity was severe, but with no death related to sepsis. Salvage chemotherapy with VM-26 or VP-16 and cisplatin offers potentially curative treatment to patients with refractory testicular cancer. The addition of radiation therapy to salvage chemotherapy was also effective.

Correlation of c-myc expression with nuclear pleomorphism in human renal cell carcinoma

The expression of the c-myc gene product in renal cell carcinomas was examined by immunostaining with monoclonal antibody (mAb) MYC-1. The effects of preservation and fixation of tissues on staining were first examined. In cryostat sections fixed with 4% buffered formalin for 15 min, staining was observed in the nucleus. On the other hand, in paraffin sections after fixation with 10% formalin, staining was observed in the cytoplasm, but not in the nucleus. Because c-myc protein has been shown to be a nuclear protein, the finding that c-myc protein was not detectable in the nucleus appeared to be due to the preservation or fixation procedures used. Therefore, cryostat sections fixed with 4% formalin were used to investigate the correlation between the reaction of MYC-1 mAb and nuclear pleomorphism in primary and metastatic renal cell carcinomas. Among 41 primary tumors, positive staining was observed in 2 of 17 tumors (12%) of grade 1, 17 of 21 (81%) of grade 2, and all 3 (100%) of grade 3. Among 17 metastatic tumors, positive staining was not observed in any of the 5 (0%) of grade 1 but was observed in 2 of 4 (50%) of grade 2 and all 8 (100%) of grade 3. Thus, the frequency of the positive reaction with MYC-1 mAb was correlated with nuclear pleomorphism in primary and metastatic renal cell carcinomas. The reaction of Ki-67 mAb, which recognized a nuclear antigen present in proliferating cells, was also correlated with nuclear pleomorphism. These findings suggest that the c-myc gene product plays a role in cell proliferation in renal cell carcinomas.

[A case of primary ureteral squamous cell carcinoma associated with calculus]

A case of primary squamous cell carcinoma of the ureter associated with ureteral calculus is presented. A 66-year-old woman was admitted to our hospital, with the chief complaint of macroscopic hematuria in October, 1985. A kidney-ureter-bladder X-ray and drip intravenous pyelography failed to reveal the calculus shadow clearly. However, computerized tomographic scan revealed the calculus shadow clearly adjacent to the ureteral tumor, and retrograde pyelography revealed the filling defect on a third lower portion of the left ureter. She was diagnosed with tumor of the ureter associated with the calculus. She underwent complete nephroureterectomy with excision of a periureteral cuff of the bladder. The tumor was diagnosed histologically as squamous cell carcinoma. Metastases and recurrence of tumor have never occurred on July, 1987. Forty-four cases of the primary ureteral squamous cell carcinoma could be collected in the Japanese literature. Moreover, we deal with this disease associated with the ureteral calculus.

Mutagenicity and nitropyrene concentration of indoor air particulates exhausted from a kerosene heater

The particulates in a room warmed with a radiant kerosene heater were collected, extracted and fractionated into diethyl ether-soluble neutral, acidic and basic fractions. The mutagenicity of these fractions was measured with Salmonella typhimurium strains TA98, TA98NR, TA98/1,8-DNP6 and TA100 in the presence and absence of S9 mix. Room air without the heater showed very low mutagenicity. However, a sample from a room at the beginning of the burning period showed very high mutagenicity (237 His+ revertants/plate/m3 of air in strain TA98 in the absence of S9 mix). In contrast, emissions from the heater after it was burning stably showed low mutagenicity (9 His+ revertants/plate/m3). The crude extract of particulates from the heater at the beginning of the burning period was analyzed by high-pressure liquid chromatography (HPLC) and showed a considerable amount of nitropyrenes (NPs); the concentrations of 1-NP and 1,6-diNP were 1.62 ng and 0.149 ng/m3 of air, respectively, and accounted for 1.2% and 17.6%, respectively, of the mutagenicity in strain TA98 in the absence of S9 mix. In addition, an HPLC-Ames histogram showed that peaks of mutagenicity corresponding to 1-NP and diNPs accounted for 75.7% (1-NP, 4.9%; 1,6-diNP, 17.1%; 1,8-diNP, 46.3%; 1,3-diNP, 7.4%) of the HPLC-recovered mutagenicity for strain TA98 without S9 mix. These results that kerosene heaters, especially immediately after ignition, create mutagenic substances such as NPs.

In vitro intestinal microflora-mediated metabolism of biliary metabolites from 1-nitropyrene-treated rats

To investigate the modifying role of the intestinal microflora in the metabolism of 1-nitropyrene (1-NP) via enterohepatic circulation, we collected bile from male Wistar rats administered [3H]1-NP orally. The bile was mixed with the intestinal contents (IC) prepared from untreated rats and the mixture was incubated anaerobically under an atmosphere of nitrogen at 37 C. Samples of the reaction mixture were removed at intervals to assay their mutagenic potential, to determine the radioactivity bound to the IC, and for analysis of the biliary metabolites. The binding of the radioactivity to the IC increased linearly as a function of time during the 1-hr incubation. The time-dependent binding does not occur with heat-treated IC and the binding was inhibited by addition of D-saccharic acid 1,4-lacton, a beta-glucuronidase inhibitor. The mutagenicity (for Salmonella typhimurium strain TA98 without S9 mix) of the bile increased early in the incubation period and then decreased very rapidly. The mutagenicity of the bile was also enhanced by treatment with a sonicated IC extract or beta-glucuronidase, but not with a heat-treated IC or aryl-sulfatase. The metabolites produced after the bile was incubated for short periods with the IC were mainly nitrohydroxypyrenes; at later times nitroreduction occurred. The level of acetylaminohydroxypyrenes, which were formed by deconjugation, did not change during the incubation. To determine the degree of contribution of the IC to the total acetylating capacity, we measured acetyltransferase activity of the IC and various organs in Wistar rats. The liver had the highest N-acetyltransferase activity among the seventeen organs examined. Considerable activity was also detected in the kidney, small intestine, lung, and testis, but the IC showed very low activity. The acetylating capacity of the IC was 0.27% of the total capacity in rats, and that of the liver was more than 80%. These results suggest that the nitrohydroxypyrenes formed from 1-NP in the liver were conjugated to glucuronic acid and excreted via the bile duct into intestine. Hydrolysis of these glucuronide conjugates by bacterial beta-glucuronidase liberated into intestine, free nitrohydroxypyrenes, which were direct-acting mutagens. The released aglycons were then rapidly nitro-reduced by intestinal microflora, but contribution of the intestinal microflora to acetylation of the reduced metabolites is very low.

Detection of mutagenic compounds in the urine of mice administered pyrene during exposure to NO2

The urine of mice injected intraperitoneally with pyrene during exposure to NO2 was found to contain highly mutagenic compounds by means of the Ames test using Salmonella typhimurium strain TA98. The mice were exposed to 20 ppm NO2 for 3 days before intraperitoneal injection of pyrene (800 mg/kg of body weight). The pyrene-treated mice were further exposed to NO2 for an additional 24 hr, and the urine from the mice was collected in ice-cooled containers and stored frozen in the dark. The collected samples were treated with beta-glucuronidase and passed through activated Sep-Pack C18 cartridges. After elution with methanol, the effluent was concentrated and the residue was dissolved in dimethyl sulfoxide (DMSO). The DMSO solution was fractionated by high-performance liquid chromatography and the mutagenicity of each fraction was assayed with S. typhimurium strain TA98. The mutagenic compounds 3-hydroxy-1-nitropyrene, 6-hydroxy-1-nitropyrene, 8-hydroxy-1-nitropyrene, and 1-hydroxypyrene were identified in the mutagenic fractions by mass spectrometry and UV-visible spectrophotometry with synthetic reference substances. These mutagenic compounds may have been formed by either nitration of hydroxylated pyrene, or hydroxylation of 1-nitropyrene, which is formed in vivo from pyrene and NO2, or the simultaneous occurrence of these two reactions in the mouse body.

Postoperative systemic adjuvant chemotherapy for bladder cancer

Forty-six patients with bladder cancer without distant metastasis (M0) were treated by chemotherapy as an adjuvant after total cystectomy using three protocols (protocol I: adriamycin 50 mg/m2, cyclophosphamide 500 mg/m2, and cis-platinum 50 mg/m2 i.v., starting at least 2 weeks after surgery every 3 weeks for three cycles; protocol II: adriamycin 30 mg/m2 on the 1st postoperative day, cyclophosphamide 300 mg/m2 on the 1st and the 7th days; protocol III: FT-207 60 mg/m2, p.o. every day for 1 year). Average follow-up periods after surgery by protocol were 18 months for protocol I, 31 for protocol II, and 43 for protocol III. Analysis of the survival curves showed no statistically significant differences among the three groups or between a historical control group of 106 patients and the entire patient population examined in the present study. The histopathological grades recorded in the 46 patients were G1, G2, and G3 in 1, 22, and 23, respectively. However, from a study of 48 pT3 and pT4 cases, the survival rate of 10 patients receiving protocol I therapy was statistically significantly higher than those of 12 patients treated according to protocol II and of 26 historical controls, at 1 year and 2 years, respectively. Toxic effects, with gastrointestinal symptoms including nausea and vomiting and myelosuppression (including leukopenia and anemia) were more frequent with protocol I. Alopecia occurred in about 80%-90% of patients treated according to either protocol I or II. Almost all patients could tolerate adjuvant chemotherapy, and none of them died as a result of these regimens. The results recorded in this study justify the evaluation of combination adjuvant chemotherapy with adriamycin, cyclophosphamide and cis-platinum in a prospectively randomized trial.

Genotoxicity of a variety of nitroarenes in DNA repair tests with human hepatocytes

The genotoxicities of 8 nitroarenes, i.e., 1-nitropyrene, 1,3-dinitropyrene, 1,6-dinitropyrene, 1,8-dinitropyrene, 2,7-dinitrofluorene, 3-nitrofluoranthene, 1-nitro-3-hydroxypyrene and 1-nitro-3-acetoxypyrene, were examined in DNA repair tests using human isolated hepatocytes. Out of the tested nitroarenes, 5 compounds, i.e., 1-nitropyrene, 1,3-dinitropyrene, 1,6-dinitropyrene, 1,8-dinitropyrene and 1-nitro-3-acetoxypyrene, clearly elicited positive responses of DNA repair. Among the chemicals which elicited positive responses, the levels of unscheduled DNA synthesis induced by the three dinitropyrene isomers were much higher than those of the other nitroarenes. Three chemicals, i.e., 2,7-dinitrofluorene, 3-nitrofluoranthene and 1-nitro-3-hydroxypyrene, elicited negative responses. The negative responses of 2,7-dinitrofluorene and 3-nitrofluoranthene, which had been positive in DNA repair tests with rodent hepatocytes, suggest some species differences between humans and rats in the metabolic activity of hepatocytes toward these agents.

[A case of signet ring cell carcinoma of the urinary bladder]

A 51-year-old man was hospitalized with complaints of gross hematuria and terminal micturition pain. Cystoscopy revealed a low columnar tumor at the dome of the bladder. Ultrasonography and X-ray CT also demonstrated the same shape of tumor and no evidence of invasion to adjacent organs. Gastrointestinal examination, including upper gastrointestinal series and barium enema failed to reveal any primary tumor. The serum CEA level was 2.3 ng/ml, which was not elevated. Total cystectomy with ileal conduit and adjuvant chemotherapy consisting of cyclophosphamide, adriamycin and cisplatinum was performed. He died of a recurrent tumor 2 years and 2 months after the operation. Besides our experience of primary signet ring cell carcinoma of the urinary bladder, a review of the literature is reported.

[Review of ureteral carcinoma as seen in mapping of the cystectomized bladder]

The incidence of unexpected ureteral carcinoma on mapping and recurrence of upper urinary tract urothelial cancer was examined in 160 patients who had undergone total cystectomy for vesical cancer and complete mapping of the specimens between May, 1978 and June, 1986 at our Center. Unexpected carcinoma in the ureteral stump was found in 5 patients (3.1%) and recurrent cancer in the upper urinary tract developed in 2 (1.3%) of the 160 patients. The incidence was higher in the recurrent bladder cancer cases, and also higher in patients with non-visible, high grade and superficial tumors of the bladders.