Inhibitory effects of tea extracts on the mutagenicity of 1-methyl-1, 2,3,4-tetrahydro-beta-carboline-3-carboxylic acid on treatment with nitrite in the presence of ethanol

It has been shown that the mutagenicity of 1-methyl-1,2,3, 4-tetrahydro-beta-carboline-3-carboxylic acid (MTCCA), a major mutagen precursor in soy sauce on treatment with nitrite and ethanol, was strongly decreased by the addition of hot water extracts of green, black and oolong teas in the reaction mixture when it was treated with 50mM nitrite at pH3.0, 37 degrees C for 60min in the presence of 7.5% ethanol. The mutagenicity-decreasing activity of the teas was scarcely decreased by washing the teas with chloroform and benzene and was partly decreased by butanol and ethyl acetate. Typical polyphenols such as catechins were shown to have the antimutagenicity dose dependently. The antimutagenicity and the reducing power of tea extracts gave a positive good correlation. The results suggest that the mutagenicity of MTCCA on treatment with nitrite in the presence of ethanol may be decreased by the mixed fractions of lyophilic components such as polyphenols, which have high reducing power such as catechins and the other compounds which have little reducing power including the derivatives of the catechins and so on. Although the antimutagenicity of teas and catechins was also considerably effective when they were added after the nitrosation, that of black tea and some catechins was less effective.

Incidence rate of satellite tumors in renal cell carcinoma

BACKGROUND

Nephron-sparing surgery for incidentally detected small renal tumors has been performed. The main objection to such surgery concerns the incidence rate of satellite renal tumors. In this study, the authors analyzed the rate of incidence and proliferative potential of satellite renal tumors.

METHODS

The tumors of 124 renal cell carcinoma patients with a clinically identified unilateral and single tumor measuring </=90 mm who were examined between November 1991 and May 1997 were analyzed prospectively. The authors determined whether these specimens obtained by radical nephrectomy had satellite tumors, and whether the satellite tumors were reactive with a monoclonal antibody (MoAb), MIB-1, to assess their proliferative potential.

RESULTS

Satellite renal cell carcinomas were detected in 8 of the 124 patients (6.5%). None of the pathologic variables examined (tumor grade, tumor stage, main tumor size, cell pattern, and vascular invasion) were found to be predictive of the presence of satellite tumors. Of these eight tumors, two main tumor specimens and three satellite tumor specimens reacted with the MIB-1 MoAb. The reactivity of MIB-1 correlated with the tumor grade. The satellite tumors were observed to have a proliferative potential compared with the main tumors. Among 86 kidney specimens from patients with urothelial tumors after total nephroureterectomy, 2 (2.3%) contained small renal cell carcinoma but did not show positive staining with the MoAb MIB-1.

CONCLUSIONS

The incidence rate of satellite tumors among 124 renal cell carcinoma patients was 6.5% and the presence of satellite tumors was not predictable. Some of these satellite tumors showed positive staining with the MIB-1 MoAb, but small renal tumors detected in kidney specimens with urothelial tumors did not.

[Results of chemotherapy and salvage surgery for advanced testicular cancer]

Since 1980, 73 patients with advanced testicular cancer have been treated with chemotherapy and 43 patients received post-chemotherapy (salvage) surgery. The median age of all patients was 31 years old, ranging from 17 to 63 years. The histology of the primary testicular tumor was pure seminoma in 23 patients and non-seminoma in 50 patients. According to the Japan Urological Association classification, 38 patients were classified as stage II and 35 patients as stage III. As first-line chamotherapy, 52 patients were treated with PVB regimen (cisplatin, vinblastin, bleomycin), 16 patients with PEB (cisplatin, etoposide, bleomycin) and 5 patients with VAB-6 (vinblastine, actinomycin-D, bleomycin, cisplatin, cyclophosphamide). Thirty (41%) of the 73 patients achieved a complete response (CR) with chemotherapy alone and 63 (86%) achieved no evidence of disease (NED) with salvage treatment. As second-line chemotherapy, 16 patients were treated with PE (cisplatin, etoposide), or VIP (etoposide, ifosfamide, cisplatin) or VeIP (vinblastine, ifosfamide, cisplatin). One of the 16 patients achieved CR and 11 (69%) patients achieved NED. As salvage surgery, retroperitoneal lymphnode dissection (RPLND) was performed in 22 patients, RPLND with thoracotomy in 7 cases and thoracotomy alone in 4 cases. Necrosis was found in surgical specimens of 24 (56%) patients, mature teratoma in 6 (14%) and residual cancer in 13 (30%). Ninety-six percent and 100% of the patients with necrosis and mature teratoma survived with NED, respectively, but only 54% of the patients with residual carcinoma survived despite further treatment. Residual cancer was still found in 8 of the 32 (25%) marker normalized cases. Residual cancer could not reliably be predicted or discriminated from necrosis or mature teratoma by the prognostic criteria. Therefore, salvage surgery remains essential in the treatment of advanced testicular cancer.

Characteristics of cardiovascular morphology and function in the high-normal subset of hypertension defined by JNC-VI recommendations

A cross-sectional study was conducted to compare the morphological and functional characteristics of the cardiovascular system among subgroups of hypertension defined by the JNC-VI recommendations. One hundred and sixteen subjects (normotensives and unmedicated hypertensives: 49+/-10 yr) were classified into 4 groups based on the criteria of JNC-VI: normotensive (NOR: n = 38), high-normal blood pressure (HN: n = 16), stage 1 hypertensive (SI: n = 28), and stage 2 to 3 hypertensive (SII-III: n = 34). Ultrasonographic examinations of the heart and carotid artery were performed in all subjects, and the following parameters were obtained: left ventricular mass index (LVMI), relative wall thickness at end-diastole (RWTd), cardiac diastolic function (A/E), common carotid artery diameter (CAD), intimal media thickness of the common carotid artery (IMT), and distensibility of the common carotid artery (Distens). RWTd, A/E, and IMT in SI (RWTd, 0.41+/-0.07; A/E, 1.21+/-0.41; IMT, 0.69+/-0.17 mm) and SII-III patients (0.40+/-0.08, 1.38+/-0.33, 0.80+/-0.21 mm) were larger than those in NOR patients (0.33+/-0.03, 0.86+/-0.21, 0.56+/-0.10 mm) (p < .01). Furthermore, LVMI in SII-III (135.5+/-35.5 g/m2) patients was larger than that in NOR patients (99.4+/-17.5 g/m2) (p < .05). RWTd in HN patients (0.37+/-0.06) was significantly higher than that in NOR patients (p < .05). A/E tended to be larger in HN than in NOR patients (p < 0.1). In the normotensives, no significant difference in any of the parameters was detected between those with optimal (n = 19) and normal (n = 19) blood pressure. Thus, both morphological and functional changes were associated with elevation of blood pressure. Cardiac morphological adaptation and functional impairment were present even in subjects with high-normal blood pressure level, while there were no significant differences between the normal and optimal subsets.

Evaluation of the development of intestinal function in rats reared on hydrolyzed or native protein-based milk formula

BACKGROUND

In recent years, hydrolyzed protein has often been used as a protein source in food products, including infant formula. In the current study, the effects of different protein sources in milk formula on the development of intestinal function in artificially reared rats were examined.

METHODS

Rat pups were artificially reared on casein-whey protein-based, whey protein-based, or hydrolyzed whey protein-based milk formula, and the intestinal lactase and maltase activities and the capacity of intestinal immunoglobulin (Ig)G uptake in these rats during the suckling period were determined.

RESULTS

There were no significant differences in the activities of disaccharidases among the three groups. In the rats reared on hydrolyzed whey protein milk formula, the plasma and jejunal concentrations of human IgG 2 hours after intragastric administration of human IgG were significantly lower than those of rats reared on milk formulas containing native proteins.

CONCLUSIONS

The present results suggest that the presence of native protein in milk formula and maternal milk may be important for jejunal IgG uptake in suckling rats and the possibility that the presence or absence of native protein in milk formula can modify some developmental processes of the small intestine in suckling animals.

Thimet oligopeptidase cleaves the full-length Alzheimer amyloid precursor protein at a beta-secretase cleavage site in COS cells

We developed an assay method using a novel quenched fluorescent substrate (QFS) flanking the beta-cleavage site of amyloid precursor protein (APP), and purified a candidate beta-secretase from bovine brain. N-terminal amino acid analysis showed the candidate to be thimet oligopeptidase (TOP). The cDNA for human TOP was cloned from a human brain cDNA library and expressed in COS cells. The enzyme was further purified on a Ni2+-agarose column. TOP cleaved the Swedish Alzheimer's substrate (SEVNLDAEFR) as well as the normal substrate (SEVKMDAEFR). We then coexpressed TOP with APP695 in COS cells, collected transfected cells and conditioned media, and analyzed them by immunoblotting. The antibody against the specific secreted APP cleaved by beta-secretase (sAPPbeta) detected the secretion of sAPPbeta only from APP/hTOP-overexpressing cells, and not from cells overexpressing of antisense hTOP cDNA. Finally, we analyzed the immunolocalization of overexpressed hTOP in COS cells. Most hTOP was localized in the nuclei, but a small amount was localized in the Golgi or other organelles around the nuclei. These results suggest that TOP has a beta-secretase-like activity responsible for the processing of APP.

Effects of roselle (Hibiscus sabdariffa Linn.), a Thai medicinal plant, on the mutagenicity of various known mutagens in Salmonella typhimurium and on formation of aberrant crypt foci induced by the colon carcinogens azoxymethane and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in F344 rats

The 80% ethanol extract of roselle (Hibiscus sabdariffa Linn.), a medicinal plant in Thailand, was examined for antimutagenic and chemopreventive activity in a colon carcinogenesis model. It reduced about 60-90% of the mutagenicity induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and other heterocyclic amines 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline(MelQ),2-amino-3, 8-dimethylimidazo[4,5-f]quinoxaline(MelQx),3-amino-1,4-dimet hyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2),2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1),2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2), at a concentration of 12.5 mg/plate in the Salmonella mutation assay. The extract showed no mutagenicity and no antibacterial activity below this dose. Mutagenicity of methylazoxymethanol (MAM) acetate, which, like PhIP, is a colon carcinogen,was also efficiently inhibited by the roselle extract. To investigate chemoprevention by roselle in a colon carcinogenesis model, we examined the inhibitory effects of the roselle extract in F344 rats in which aberrant crypt focus (ACF) formation was induced by azoxymethane (AOM) and PhIP. In the initiation stage, the number of AOM-induced ACF in the colon was significantly decreased by roselle (17-25%) compared with that in rats treated with AOM alone. The amount of O6-methylguanine in the colonic mucosa tended to be decreased in the roselle-treated rats. The number of PhIP-induced ACF was also significantly decreased by roselle treatment (22%) at a concentration of 1.0 g/kg body weight in the initiation stage. However, in the post-initiation stage of AOM-induced ACF formation, roselle increased the number of ACF, especially the number of foci which had more than three crypts/focus. These results indicate that roselle has antimutagenic activity against MAM acetate and heterocyclic amines and that it decreases the number of AOM- and PhIP-induced ACF in the initiation stage, although it rather increased the number of ACF in the post-initiation stage.

[Renal oncocytoma with cystic degeneration: a case report]

A 45-year-old man was referred to our department because of a right renal mass which was incidentally found at a health screening. Ultrasound sonography, computerized tomography and magnetic resonance imaging showed a hypovascular tumor 3 cm in diameter with the fluid at the upper pole of the right kidney, implicating that the tumor was renal cell carcinoma originating from a renal cyst wall, or with central necrosis. A radical nephrectomy was therefore performed. The tumor was dark-brown and contained brown fluid. The histopathological findings showed renal oncocytoma with cystic degeneration.

Impact of tumor size on the clinical outcomes of patients with Robson State I renal cell carcinoma

BACKGROUND

In the TNM classification of renal cell carcinoma released in 1997, T1 tumors were defined as organ-confined tumors 7.0 cm or less in size, and T2 as those larger than 7.0 cm. The consideration of tumor size should be predicated on its prognostic value in predicting survival, because the goal of clinical staging is to separate patients into similar classes of survival based on the extent of disease at presentation. The authors examined the impact of tumor size on the clinical outcomes of patients with Robson Stage I disease to determine a size cutoff that would maximize the predictive value of the TNM staging system.

METHODS

Between 1962 and 1995, 382 patients with renal cell carcinoma were treated at the Department of Urology at the Osaka Medical Center for Cancer and Cardiovascular Diseases in Osaka, Japan, and the TNM staging of 350 of those patients was recorded. Of 350 patients, 157 (45%) were at TNM Stage I, 47 (13%) at Stage II, 65 (19%) at Stage III, and 81 (23%) at Stage IV, according to the TNM stages defined in 1997. Robson Stage I includes TNM Stages I and II, and 204 patients in these stages were analyzed in this study. This study group included 146 men and 58 women with a mean age of 57.8 years (range, 26-84 years). The mean follow-up period was 5.4 years.

RESULTS

The patient survival periods were not significantly different for those with TNM Stages I and II. This finding indicated that the tumor size cutoff of 7.0 cm was not useful in predicting the prognosis. The patients at TNM Stages I and II were then divided into two groups at each size cutoff, from 2.5 cm to 9.0 cm, at 0.5-cm intervals. The tumor size cutoff of 5.5 cm was most predictive of patient survival (P = 0.0121). None of other patient characteristics varied significantly between the two groups at this dichotomous point. Tumor size and microscopic intrarenal venous invasion, but not grade or infiltration pattern, were found in univariate and multivariate analyses to be significantly predictive of the survival of Robson Stage I patients after radical nephrectomy.

CONCLUSIONS

The current data indicate that the tumor size cutoff of 5.5 cm was most significantly predictive of the survival of Robson Stage I patients after radical nephrectomy. The tumor size cutoff of 5.5 cm was also shown to be significant in univariate and multivariate analyses.

Protective effects of a culture supernatant of Lactobacillus acidophilus and antioxidants on ileal ulcer formation in rats treated with a nonsteroidal antiinflammatory drug

Ileal ulcers and thiobarbituric acid (TBA)-reactive substances in the ileal mucosa were induced in rats treated with a nonsteroidal antiinflammatory drug, 5-bromo-2-(4-fluorophenyl)-3-(4-methylsulfonylphenyl)thiophene (BFMeT), at a dose of 1,000 mg/kg administered with tap water as drinking water. However, the formation of ileal ulcers and TBA-reactive substances in the ileal mucosa was repressed by giving the animals a culture supernatant of Lactobacillus acidophilus as drinking water. We measured the antioxidative activity of the culture supernatant and found that the supernatant inhibited the formation of t-butyl hydroperoxide-induced TBA-reactive substances in erythrocyte membrane ghosts. Therefore, the effects of various known antioxidative compounds on the ileal ulcer formation induced by BFMeT were investigated. While alpha-tocopherol, t-butyl-1,4-hydroxyanisole and allopurinol did not repress ulcer formation after BFMeT treatment, ascorbic acid, dimethyl sulfoxide, glutathione and beta-carotene significantly inhibited formation. Among these compounds, ascorbic acid was the most effective. Accumulation of TBA-reactive substances in the ileal mucosa after BFMeT treatment also decreased significantly in rats treated with ascorbic acid. In addition, the percentage of gram-negative rods in the ileal contents of rats treated with BFMeT and tap water was dramatically increased, but it was not increased in rats treated with BFMeT and these antioxidants. A positive correlation between the percentage of gram-negative rods and the number of ileal ulcers was also observed. These results suggest that lipid peroxidation mediated by oxygen radicals plays an important role in the induction of ileal ulcers by BFMeT in rats, and that lipopolysaccharide-activated neutrophils probably produce highly reactive hypochlorous acid and hydrogen peroxide, which are inactivated by ascorbic acid and glutathione, respectively.

The deletion of the C-terminal tail and addition of an endoplasmic reticulum targeting signal to Alzheimer's amyloid precursor protein change its localization, secretion, and intracellular proteolysis

The metabolic pathway of Alzheimer's amyloid precursor protein (APP) involves restricted intracellular proteolysis by secretases, which leads to the secretion of the N-terminal soluble APP (sAPP) and the generation of a cell-associated C-terminal fragment. The precise cellular sites at which these processes occur remain unknown. In this report, we describe the route of APP sorting and the processing site using novel systems with and without sorting signals on the APP molecule. One system involves the replacement of the C-terminal ten amino acids of APP with Adenoviral E19 protein containing an endoplasmic reticulum (ER) retrieval signal (APPE19); the other involves deleting the last ten amino acids corresponding to the replaced site (APPdeltaC10). APPE19 localized mainly within the cis/medial Golgi compartment and exclusively suppresses the secretion of APP. In contrast, deletion of the C-terminal tail promotes sAPP secretion by a constitutive secretion pathway. Metabolic labeling followed by immunoprecipitation with anti-APP antibody revealed that APPE19 is rapidly degraded within 30 min and that the subsequent intracellular turnover rate is decreased with 40% of the protein retained within the cells even after a chase period a 3 h. In contrast, APPdeltaC10 is rapidly eliminated from the intracellular compartments and secreted into the culture medium. The surface internalization and recycling processes of this protein are relatively impaired compared with wild-type APP. The ratios of the levels of production to secretion of sAPP alpha, the N-terminal, soluble APP fragment released by alpha-secretase, are proportional to the secretion efficiencies among APP species, suggesting the localization of alpha-secretase within a compartment late in the constitutive secretion pathway. These secretion mutants which utilize ER targeting signals are useful tools for analyzing the location of secretases and the intracellular degradation system within a constitutive secretion pathway such as ER quality control.