A thirteen-week oral toxicity study of annatto extract (norbixin), a natural food color extracted from the seed coat of annatto (Bixa orellana L.), in Sprague-Dawley rats

A subchronic oral toxicity study of annatto extract (norbixin), a natural food color, was conducted. Groups of 10 male and 10 female Sprague-Dawley rats were fed annatto extract at dietary levels of 0, 0.1, 0.3 and 0.9% for 13 weeks. There were no treatment-related adverse effects on body weight, food and water consumption, ophthalmology and hematology data. Blood biochemical analysis revealed changes in rats of both sexes confined to the 0.9% and 0.3% groups, including increased alkaline phosphatase, phospholipid, total protein, albumin and albumin/globulin ratio. Marked elevation in absolute and relative liver weights was also found in both sexes of the 0.9% and 0.3% groups, but not the 0.1% group. Hepatocyte hypertrophy was evident and an additional electron microscopic examination demonstrated this to be linked to abundant mitochondria after exposure to a dietary level of 0.9% annatto extract for 2 weeks. Thus, the No-Observed-Adverse-Effect-Level (NOAEL) was judged to be a dietary level of 0.1% (69 mg/kg body weight/day for males, 76 mg/kg body weight/day for females) of annatto extract (norbixin) under the present experimental conditions.

Adenocarcinoma and multiple adenomas of the large intestine, associated with Cronkhite-Canada syndrome

The Cronkhite-Canada syndrome is a rare non-hereditary disorder with generalised gastrointestinal polyposis, associated with ectodermal changes. We report here a case of adenocarcinoma and multiple adenomas of the large intestine associated with Cronkhite-Canada syndrome in a 61-year-old Japanese man. Histologically, the rectal tumour was composed of well-differentiated tubular adenocarcinoma, admixed with foci of adenomatous components, and associated with hyperplastic mucosa of Cronkhite-Canada syndrome. Multiple polyps, >20 polyps < or = 2.0 cm in diameter, were found near the carcinoma of the resected rectum. Histologically, superficial parts of the polyps were composed of tubular adenomas, and basal parts of the polyps were hyperplastic dilated glands. It was speculated that, in the present case, the rectal adenocarcinoma arose from mucosal hyperplasia (Cronkhite-Canada polyp)-adenoma-carcinoma pathway. This suggested that Cronkhite-Canada syndrome has definite malignant potential, although the frequency of malignant transformation is thought to be low in Cronkhite-Canada syndrome.

Prenatal and neonatal exposure to bisphenol-A enhances the central dopamine D1 receptor-mediated action in mice: enhancement of the methamphetamine-induced abuse state

Bisphenol-A (BPA), one of the most common environmental endocrine disrupters, has been extensively evaluated for toxicity in a variety of tests in rodents, including developmental and reproductive toxicity, and carcinogenicity. However, little is known about its action on the CNS. In this report, we show that prenatal and neonatal exposure to BPA in mice leads to the enhancement of the dopamine D1 receptor-dependent rewarding effect induced by a psychostimulant methamphetamine. Furthermore, this treatment with BPA markedly enhanced hyperlocomotion and its sensitization induced by methamphetamine, which reflects extensive abuse associated with sociological and psychiatric problems. We also demonstrated that chronic exposure to BPA produced an up-regulation of dopamine D1 receptor function to activate G-protein in the mouse limbic forebrain, which is thought to be a critical site for the expression of rewarding effects by abuse drugs. Additionally, chronic BPA exposure produced a significant increase in levels of the dopamine D1 receptor mRNA in the whole brain. In contrast, no change in protein levels of methamphetamine-targeted proteins, dopamine transporter or the type 2 vesicle monoamine transporter in the brain was observed by prenatal and neonatal exposure to BPA. The present data provide the first evidence that prenatal and neonatal exposure to BPA can potentiate the central dopamine D1 receptor-dependent neurotransmission, resulting in supersensitivity of methamphetamine-induced pharmacological actions related to psychological dependence on psychostimulants.

Blood-pressure-lowering effect of a novel fermented milk containing gamma-aminobutyric acid (GABA) in mild hypertensives

OBJECTIVE

To study the effect of a new fermented milk product containing GABA (FMG) on the blood pressure (BP) of patients with mild hypertension.

DESIGN

A randomized, placebo-controlled, single-blind trial.

SETTING

The study was carried out at the outpatient clinic of the Cardiovascular Disease Center, Tokyo Metropolitan Police Hospital, Japan.

SUBJECTS

The study population comprised 39 mildly hypertensive patients (16 women and 23 men) aged 28-81 y (mean, 54.2 y).

INTERVENTIONS

The study consisted of a 12-week period of daily intake of FMG or placebo (weeks 1-12) followed by 2 weeks of no intake (weeks 13 and 14). We measured the peripheral BP and heart rate of seated patients at weeks 0, 2, 4, 8, 12 and 14. Routine blood study and urinalysis were performed before and after the intake.

RESULTS

There was a significant decrease of BP within 2 or 4 weeks, and it remained decreased throughout the 12-week intake period. For the FMG recipients, the mean decrease after 12 weeks was 17.4+/-4.3 mmHg in the systolic BP (SBP) and 7.2+/-5.7 mmHg in the diastolic BP (DBP). Both of these values differed statistically from baseline levels (P<0.01), and the SBP of the FMG group differed from the placebo group (P<0.05). Heart rate, body weight, hematological and blood chemistry variables, and urinalysis results (glucosuria and proteinuria) did not vary both groups throughout the study.

CONCLUSION

FMG may contribute to lowering BP in mildly hypertensive people.

Th1/Th2 profile in peripheral blood in atopic cough and atopic asthma

BACKGROUND

Eosinophilic tracheobronchitis with cough hypersensitivity, abbreviated as atopic cough, is an important cause of chronic cough. The reason for the absence of airway hyper-responsiveness is unknown, differing from asthma, a Th2 cytokine-mediated disorder.

OBJECTIVE

To compare the type 1 helper T cell (Th1)/Th2 balance in the peripheral blood from subjects with atopic cough and atopic asthma, we assessed the intracellular cytokine production at the single-cell level.

METHODS

Thirty-six subjects (10 patients with atopic cough, 18 with atopic asthma, and eight control subjects) were included. Intracellular IL-4 and IFN-gamma were detected in CD4+ T cells by flow cytometry.

RESULTS

A significantly lower ratio of IFN-gamma-/IL-4-producing CD4+ T cells after phorbol 12-myristate acetate/ionomycin stimulation was found in patients with atopic cough and atopic asthma compared with normal subjects. In comparison between atopic patients, the ratio of IFN-gamma-/IL-4-producing cells was significantly higher in atopic cough than in atopic asthma. However, the proportion of IL-4-producing CD4+ T cells was significantly higher in patients with atopic asthma than in normal control subjects and no significant difference was detected between patients with atopic cough and normal subjects. No significant difference in the proportion of IFN-gamma-producing cells was found between the subjects. Overall, the total IgE levels were positively correlated to the IL-4-producing cells and inversely correlated to the ratio of IFN-gamma-/IL-4-producing cells.

CONCLUSION

These results show the lower degree of Th2 cytokine predominance in atopic cough compared with atopic asthma and suggest the relation between the Th1/Th2 balance and atopic status.

Application of toxicogenomics to the endocrine disruption issue

Toxicogenomics can be expected to be a useful method for detecting the carcinogenic potential of endocrine active substances (EASs) in the short term with the generation of understanding of mode-of-action and mechanisms when a reliable database with information about proteomics and informatics is established. At present, there are no concrete epidemiological data supporting any exogenous EAS contribution to hormone-related organ carcinogenesis in humans. However, with the establishment of appropriate animal models and analysis of genomic-scale gene expression, risk identification and evaluation should be facilitated within a relatively short period, and this approach eventually promises to contribute a great deal of risk management regarding EASs.

Dose-dependent promotion by phenylethyl isothiocyanate, a known chemopreventer, of two-stage rat urinary bladder and liver carcinogenesis

The effects of phenylethyl isothiocyanate (PEITC) on urinary bladder and liver carcinogenesis were analyzed in a rat model. Diets containing 0.1%, 0.05%, or 0.01% PEITC were administered for 32 wk to male Fischer 344 rats with and without pretreatment with an injection of diethylnitrosamine (200 mg/kg body wt i.p.) and 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine in the drinking water for 4 wk for initiation. In the initiated groups, PEITC administration significantly increased the incidences of papillary or nodular hyperplasia, dysplasia, and transitional cell carcinomas at higher doses of 0.01%, 0.01%, and 0.05%, respectively, compared with the control group, given initiation alone, in a dose-dependent manner. Without initiation, administration of 0.1% and 0.05% PEITC induced simple and papillary or nodular hyperplasia and dysplasia in the urinary bladder. In the liver, induction of glutathione S-transferase placental form-positive foci was dose dependently enhanced by PEITC administration, but the incidences of liver tumors were not different among the groups. From the present experiment, we can conclude that > 0.01% PEITC enhances rat urinary bladder carcinogenesis, while weakly promoting hepatocarcinogenesis. In addition, it is suggested that > 0.05% PEITC has tumorigenic potential.

Organ differences in the enhancing potential of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine on carcinogenicity in the prostate, colon and pancreas

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most abundant carcinogenic heterocyclic amine in cooked meat and fish, is speculated to be associated with human carcinogenesis. It has been shown to induce DNA adducts in a variety of organs in rodents and thus clarification of any enhancement of neoplasia is a very important subject for assessing human risk. In order to evaluate modifying effects of PhIP on carcinogenesis, several in vivo experiments in rats were performed. These featured dietary administration of PhIP at different dose levels and for different durations, and included intragastric dosing for a short period, or continuous dietary administration after initiation with other carcinogen, namely 3,2'-dimethyl-4-aminobiphenyl (DMAB) or 1,2-dimethylhydrazine (DMH). The data indicate that a short administration of PhIP is sufficient to induce prostate tumors but long-term treatment is required for effects in the colon. They also suggest tumor enhancing potential dependent on the organ, i.e. evident in the colon but not the prostate. Furthermore, promotion of colon neoplasia may depend on the initiator employed. Thus these findings suggest that the carcinogenic mechanisms of PhIP may vary in its different target organs.

Down-regulation of Lsm1 is involved in human prostate cancer progression

Elucidation of genetic alterations is an approach to understanding the underlying molecular mechanisms of progression of human prostate cancers. We have searched for genes differentially expressed in advanced prostate cancers using cDNA-representational difference analysis, and thereby isolated the Lsm1 as one of down-regulated gene. An Lsm1 expression vector was transfected into PC3 cells, normally featuring down-regulated Lsm1, and four transfectants were established. No differences in morphology or cell proliferation were evident in comparison with parent PC3 or PC3/mock-transfectants. In contrast, significant suppression of invasive potential or metastatic ability of Lsm1 transfectants was observed in the Matrigel chemoinvasion assay and in nude mice, respectively. With human prostate cancers, almost all of informative prostatectomised cases without neoadjuvant therapy showed allelic retention in the Lsm1 region, whereas refractory cancers frequently showed allelic loss in this region. No critical gene mutations were found in open reading frame of Lsm1 in prostate cancers examined by PCR-SSCP analysis, including localised and refractory cancers. These results suggest that Lsm1 is deeply involved in prostate cancer progression through its down-regulation, independent of any gene mutation.

Protective effect of acetaminophen against colon cancer initiation effects of 3,2'-dimethyl-4-aminobiphenyl in rats

A previous investigation demonstrated the anticarcinogenicity of acetaminophen (APAP) against colon carcinogenesis in rats induced by 3,2'-dimethyl-4-aminobiphenyl (DMAB). DMAB was selected as a structurally related surrogate for heterocyclic amines, formed during cooking of protein, which are believed to be involved in human colon cancer. The objective of the present study was to ascertain whether the early initiating effects of this colon carcinogen are inhibited by APAP. Six groups of male F344 rats were treated over a 6-week period as follows: (1) vehicle (corn oil) for 6 weeks; (2) APAP in the diet at 1000 ppm daily for 6 weeks; (3) 50 mg/kg DMAB by gavage once a week for the last 4 weeks; (4) 5 mg/kg DMAB as for (3); (5) 1000 ppm APAP for 6 weeks and 50 mg/kg DMAB for the last 4 weeks; and (6) 1000 ppm APAP and 5 mg/kg DMAB as for (5). Colonic tissue was within normal limits in the control and APAP groups. In the APAP only group, apical enterocytic hypertrophy and hyperaemia over the entire surface epithelium was present. In the high-dose DMAB group, in the lower third of the crypts, foci of enlarged glands with hypertrophic cells exhibiting karyomegaly and anisokaryosis (FHE) of 3+ degree of severity were evident in 100% of the animals. Also, there were increases in periglandular fibrocytes, matrix and mononuclear cells (PF). In the low-dose DMAB group both FHE and PF changes with the same degree of severity were reduced. In rats given the low dose of DMAB plus APAP, FHE and PF with the same degree of severity (3+) was absent. Both DMAB exposures increased significantly the replicating fraction of colonic enterocytes in an exposure-related fashion and the replicating fractions were significantly reduced by APAP. In 32P-postlabelling of colon, liver and urinary bladder DNA, high-dose DMAB produced 2-6 distinct dose-related spots reflecting DNA adducts. These spots were reduced or were no longer detectable in all three tissues when APAP was given 2 weeks before and during DMAB exposure. Using immunohistochemical detection of DMAB adducts in the colon, a dose-related colour intensity was present for both doses of DMAB. APAP reduced this by 94-fold. Thus, APAP produced a marked protective effect in colonic enterocytes against several parameters of neoplastic development by the carcinogen.

Abnormal IgG galactosylation in MRL-lpr/lpr mice: pathogenic role in the development of arthritis

MRL-lpr/lpr (MRL/lpr) mice spontaneously develop arthritis by an increase in the incidence of agalactosylated oligosaccharides in serum IgG, similar to rheumatoid arthritis patients. However, whether this association has a pathogenic significance is still unknown. In this study, we analyzed the oligosaccharide structure of serum IgG in various MRL mice with or without arthritis, to clarify the relationship between the oligosaccharide abnormality and the development of arthritis. The level of agalactosylation in serum IgG was comparable in both arthritis-free MRL/lpr and MRL-+/+ (MRL/+) mice at 6 weeks of age. In contrast, the incidence of IgG lacking galactose markedly increased in MRL/lpr mice at 6 months of age (the age at which arthritis occurred), compared with that from age-matched MRL/+ mice without arthritis. However, the proportion of agalactosylated IgG increased similarly in anti-CD4 monoclonal antibody-treated MRL/lpr mice at 6 months of age, despite the absence of the development of arthritis, because of depletion of CD4+ T cells. These results suggest that the abnormality in IgG galactosylation of MRL/lpr mice developed in an age-dependent manner, but it did so independently of CD4+ T cell-dependent B-cell activation and is not a consequence of the development of arthritis.

Accumulative increase of loss of heterozygosity from leukoplakia to foci of early cancerization in leukoplakia of the oral cavity

BACKGROUND

Oral leukoplakia is a premalignant lesion, but the genetic changes in the foci of early cancerization in leukoplakia have not been studied.

METHODS

Loss of heterozygosity (LOH) was successively investigated in 13 cases in the leukoplakia and foci of early cancerization in the same leukoplakia. The authors microdissected both lesions, and 33 microsatellite markers at 14 chromosomal loci were examined by a polymerase chain reaction-based microsatellite assay.

RESULTS

Loss of heterozygosity detected in the leukoplakia was identically observed in the foci of early cancerization in leukoplakia in 11 of 13 cases, and in 2 cases allelic divergence was observed. Loss of heterozygosity occurred even in the leukoplakia with high frequency at 9p21 (66.7%), 3p14-25 (61.5%), 4q31-32 (45.5%), and 17p12-14 (44.4%). The foci of early cancerization in leukoplakia showed accumulative increase of LOH at these and other loci. Loss of heterozygosity at 5q21-23 was found to have significant difference between the leukoplakia and the foci of early cancerization in leukoplakia (P = 0.0137, Fisher exact test). Microsatellite instability was observed at low level in three cases. The mean value of fractional allelic loss in the leukoplakia differed significantly from that in the foci of early cancerization in leukoplakia (0.02 < P < 0.05, Student t test).

CONCLUSIONS

The high incidence of LOH in the leukoplakia indicated premalignant potentiality of this lesion and that accumulative increase of LOH from leukoplakia to foci of early cancerization in leukoplakia might play a significant role in the cancerization of leukoplakia. Comparison of LOH between the leukoplakia and the foci of early cancerization in leukoplakia suggested that these two lesions were derived from a common clone.

Lack of promotion of 7,12-dimethylbenz[a]anthracene-initiated mouse skin carcinogenesis by 1.5 GHz electromagnetic near fields

The effects of 1.5 GHz electromagnetic near fields of time division multiple access (TDMA) signal for the Personal Digital Cellular, Japanese cellular telephone standard (PDC) used for cellular phones, on mouse skin carcinogenesis initiated by 7,12-dimethylbenz[a]anthracene (DMBA) were examined. Ten-week-old ICR female mice were treated with a single application of DMBA on shaved dorsal skin by painting at a concentration of 100 microg/100 microl acetone per mouse. One week later, mice were divided into four groups, receiving electromagnetic near fields exposure (DMBA-EMF), sham-exposure (DMBA-Sham), 12-O-tetradecanoylphorbol-13-acetate (TPA, 4 microg /200 microl acetone/mouse), as a positive control (DMBA-TPA), and no-treatment (DMBA-Control). EMF near fields exposure conditions were as follows: skin local peak specific absorption rate (SAR) 2.0 W/kg, whole body average SAR 0.084 W/kg (ratio of peak to average SAR is 24), 90 min a day, 5 days a week, for 19 weeks. At week 20, animals were killed and skin tumors were analyzed histopathologically. The incidences of skin tumors in DMBA-EMF, DMBA-Sham, DMBA-TPA and DMBA-Control groups were 0/48 (0%), 0/48 (0%), 29/30 (96.6%) and 1/30 (3.3%), respectively. Histopathologically, papilloma and squamous cell carcinoma (SCC) were observed in the DMBA-TPA group and only papilloma observed in the DMBA-Control group. The incidences of squamous cell papillomas and squamous cell carcinomas in DMBA-TPA and DMBA-Control groups were 29/30 (96.6%) and 1/30 (3.3%), respectively, numbers of tumors per mouse (tumor multiplicity) being 18.8 +/- 13.4 and 0.1 +/- 0.5. These data clearly demonstrated that near fields exposure to 1.5 GHz EMF, used for cellular phones, does not exert any enhancing effect on skin tumorigenesis initiated by DMBA.

In situ visualization of ultraviolet-light-induced DNA damage repair in locally irradiated human fibroblasts

We have developed a novel method that uses a microfilter mask to produce ultraviolet-induced DNA lesions in localized areas of the cell nucleus. This technique allows us to visualize localized DNA repair in situ using immunologic probes. Two major types of DNA photoproducts [cyclobutane pyrimidine dimers and (6-4) photoproducts] were indeed detected in several foci per nucleus in normal human fibroblasts. They were repaired at those localized sites at different speeds, indicating that DNA photoproducts remain in relatively fixed nuclear positions during repair. A nucleotide excision repair protein, proliferating cell nuclear antigen, was recruited to the sites of DNA damage within 30 min after ultraviolet exposure. The level of proliferating cell nuclear antigen varied with DNA repair activity and diminished within 24 h. In contrast, almost no proliferating cell nuclear antigen fluorescence was observed within 3 h in xeroderma pigmentosum fibroblasts, which could not repair either type of photolesion. These results demonstrate that this technique is useful for visualizing the normal nucleotide excision repair process in vivo. Interestingly, however, in xeroderma pigmentosum cells, proliferating cell nuclear antigen appeared at ultraviolet damage sites after a delay and persisted as late as 72 h after ultraviolet exposure. This result suggests that this technique is also valuable for examining an incomplete or stalled nucleotide excision repair process caused by the lack of a single functional nucleotide excision repair protein. Thus, the technique provides a powerful approach to understanding the temporal and spatial interactions between DNA damage and damage-binding proteins in vivo.

Modifying effects of propolis on MeIQx promotion of rat hepatocarcinogenesis and in a female rat two-stage carcinogenesis model after multiple carcinogen initiation

The modifying effects of the dietary administration of water- and ethanol-extracted propolis produced in Brazil (WB and EB, respectively) on 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) promotion of rat hepatocarcinogenesis were investigated in a medium-term liver bioassay system with use of male Fischer 344 rats. The number and area of glutathione S-transferase placental form (GST-P)-positive foci in rats given 0.5% WB were significantly increased compared with the group given MeIQx alone. Furthermore, the numbers of GST-P-positive foci were higher in rats given 0.1% WB or EB than in those given the basal diet alone. The modifying effects of propolis on other organs were also examined in female Fischer 344 rats given multiple carcinogens for initiation. Rats received water- and ethanol-extracted propolis produced in Brazil and Uruguay (WB, EB, WU, and EU, respectively) in the diet after exposure to three different carcinogens. The incidence of total mammary tumors was significantly lower in rats given EU than in the control group. These results indicate that a water extract of propolis exerts a cocarcinogenic effect on MeIQx hepatocarcinogenesis while promoting the effect at low dose in a two-stage hepatocarcinogenesis model. Moreover, they suggest that ethanol-extracted propolis may be an inhibitor of mammary gland carcinogenesis.

Beef tallow, but not perilla or corn oil, promotion of rat prostate and intestinal carcinogenesis by 3,2'-dimethyl-4-aminobiphenyl

The modifying effects of three kinds of fat (corn oil, beef tallow or perilla oil, each at 20% in the diet) on F344 rat prostate carcinogenesis induced by 3,2'-dimethyl-4-aminobiphenyl (DMAB) were investigated. Non-invasive carcinomas of the ventral prostate were induced by DMAB alone and invasive carcinomas of the other prostate lobes and seminal vesicles by DMAB and testosterone propionate (TP). Eight groups of F344 rats were initiated with 50 mg / kg body weight of DMAB at 2-week intervals for the first 20 weeks, four also receiving TP, extended until week 60. The animals received basal chow powder diet or one of three high fat diets throughout the experiment (60 weeks). One further group served as a non-carcinogen-treated control maintained on basal chow powder diet. Beef tallow significantly increased the development of ventral prostate carcinomas with DMAB alone (from 15 to 45%, P < 0.05), while perilla oil reduced the incidence of prostatic intraepithelial neoplasia (PIN) in the ventral lobe of rats given DMA + TP (from 70 to 10%, P < 0.01), but not in those given DMAB alone. No other effects of high fats were observed regarding PIN or invasive cancers of the dorsolateral and anterior prostate or seminal vesicles. A satellite experiment demonstrated that all high fat diets for 4 weeks increased the 5-bromo-2-deoxyuridine (BrdU) labeling index of prostate epithelial cells, suggesting that a high fat intake, irrespective of the fatty acid composition, may accelerate cell kinetics in the prostate. Of the three high fat diets, beef tallow was also found to increase intestinal carcinogenesis. Thus, the present data revealed carcinogenesis in the prostate and intestine to be promoted by beef tallow.

Pronounced inhibition by a natural anthocyanin, purple corn color, of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-associated colorectal carcinogenesis in male F344 rats pretreated with 1,2-dimethylhydrazine

The potential of purple corn color (PCC), a natural anthocyanin, to modify colorectal carcinogenesis was investigated in male F344/DuCrj rats, initially treated with 1,2-dimethylhydrazine (DMH), receiving 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in the diet. After DMH initiation, PCC was given at a dietary level of 5.0% in combination with 0.02% PhIP until week 36. No PCC-treatment-related changes in clinical signs, body weight and food consumption were found. Incidences and multiplicities of colorectal adenomas and carcinomas in rats initiated with DMH were clearly increased by PhIP. In contrast, lesion development was suppressed by PCC administration. Furthermore, in the non-DMH initiation groups, induction of aberrant crypt foci by PhIP tended to be decreased by the PCC supplementation. The results thus demonstrate that while PhIP clearly exerts promoting effects on DMH-induced colorectal carcinogenesis, these can be reduced by 5.0% PCC in the diet, under the present experimental conditions.

Haematopoietic cell-specific CDM family protein DOCK2 is essential for lymphocyte migration

Cell migration is a fundamental biological process involving membrane polarization and cytoskeletal dynamics, both of which are regulated by Rho family GTPases. Among these molecules, Rac is crucial for generating the actin-rich lamellipodial protrusion, a principal part of the driving force for movement. The CDM family proteins, Caenorhabditis elegans CED-5, human DOCK180 and Drosophila melanogaster Myoblast City (MBC), are implicated to mediate membrane extension by functioning upstream of Rac. Although genetic analysis has shown that CED-5 and Myoblast City are crucial for migration of particular types of cells, physiological relevance of the CDM family proteins in mammals remains unknown. Here we show that DOCK2, a haematopoietic cell-specific CDM family protein, is indispensable for lymphocyte chemotaxis. DOCK2-deficient mice (DOCK2-/-) exhibited migration defects of T and B lymphocytes, but not of monocytes, in response to chemokines, resulting in several abnormalities including T lymphocytopenia, atrophy of lymphoid follicles and loss of marginal-zone B cells. In DOCK2-/- lymphocytes, chemokine-induced Rac activation and actin polymerization were almost totally abolished. Thus, in lymphocyte migration DOCK2 functions as a central regulator that mediates cytoskeletal reorganization through Rac activation.

Organ dependent enhancement of rat 3,2'-dimethyl-4-aminobiphenyl (DMAB) carcinogenesis by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP): positive effects on the intestine but not the prostate

In order to evaluate tumor enhancing effects of the heterocyclic carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), doses of 100 and 300 p.p.m. PhIP were given for 40 weeks to male F344 rats, which initially received 3,2'-dimethyl-4-aminobiphenyl (DMAB). DMAB shows a similar carcinogenic organ spectrum to that of PhIP, including the prostate and colon. PhIP alone at a dose of 300 p.p.m. resulted in the development of prostate and intestine cancers. Furthermore, among the DMAB-treated group, enhancement of intestinal carcinogenesis by 300 p.p.m. PhIP was observed. However, no prostate enhancement was demonstrated in the DMAB + PhIP group. Since PhIP-DNA adduct formation in the prostate epithelial cells in a satellite experiment was not affected by pre-treatment with DMAB, it is speculated that the contradictory findings between the intestine and prostate may be due to the specific biological effects of PhIP. Taking into account previous data, that PhIP clearly enhanced rat 1,2-dimethylhydrazine-initiated colon tumorigenesis, the potential of PhIP to enhance colon carcinogenesis may be initiator dependent.

Susceptibility and negative epistatic loci contributing to type 2 diabetes and related phenotypes in a KK/Ta mouse model

The KK/Ta mouse strain serves as a suitable polygenic model for human type 2 diabetes. Using 93 microsatellite markers in 208 KK/Ta x (BALB/c x KK/Ta)F1 male backcross mice, we carried out a genome-wide linkage analysis of KK/Ta alleles contributing to type 2 diabetes and related phenotypes, such as obesity and dyslipidemia. We identified three major chromosomal intervals significantly contributing to impaired glucose metabolism: one quantitative trait locus for impaired glucose tolerance on chromosome 6 and two loci for fasting blood glucose levels on chromosomes 12 and 15. The latter two loci appeared to act in a complementary fashion. Two intervals showed significant linkages for serum triglyceride levels, one on chromosome 4 and the other on chromosome 8. The KK allele on chromosome 8 acts to promote serum triglyceride levels, whereas the KK allele on chromosome 4 acts to suppress this effect in a recessive fashion. In addition, it is suggested that the chromosome 4 locus also acts to downregulate body weight and that the chromosome 8 locus acts to upregulate serum insulin levels. Our data clearly showed that each disease phenotype of type 2 diabetes and related disorders in KK/Ta mice is under the control of separate genetic mechanisms. However, there appear to be common genes contributing to different disease phenotypes. There are potentially important candidate genes that may be relevant to the disease.

Crystal structure of alkaline cellulase K: insight into the alkaline adaptation of an industrial enzyme

The crystal structure of the catalytic domain of alkaline cellulase K was determined at 1.9 A resolution. Because of the most alkaliphilic nature and it's highest activity at pH 9.5, it is used commercially in laundry detergents. An analysis of the structural bases of the alkaliphilic character of the enzyme suggested a mechanism similar to that previously proposed for alkaline proteases, that is, an increase in the number of Arg, His, and Gln residues, and a decrease in Asp and Lys residues. Some ion pairs were formed by the gained Arg residues, which is similar to what has been found in the alkaline proteases. Lys-Asp ion pairs are disfavored and partly replaced with Arg-Asp ion pairs. The alkaline adaptation appeared to be a remodeling of ion pairs so that the charge balance is kept in the high pH range.

[Effect of highly active antiretroviral therapy (HAART) on hypergammaglobulinemia in HIV infected patients]

To investigate the mechanism of hypergammaglobulinemia in HIV infected patients, the effect of highly active antiretroviral therapy (HAART) on the hypergammaglobulinemia was analyzed. Involved in this study were 34 untreated, 21 HAART-effective (complete response) and 14 HAART-non-effective (partial response) patients. Serum levels of HIV-RNA and gammaglobulin and immunoglobulin (Ig) isotypes were measured. Mean HIV-RNA levels of untreated and partial response patients were 1.6 x 10(4) copies/ml and 0.4 x 10(4) copies/ml, respectively. HIV-RNA levels of all complete response patients were below 4.0 x 10(2) copies/ml. Mean gammaglobulin percentages of untreated, partial response and complete response patients were 24.4%, 21.8% and 17.9%, respectively (p < 0.01 in untreated vs complete response patients). Mean IgG levels in the three groups were 2,489 mg/dl, 1,947 mg/dl and 1,618 mg/dl, respectively (p < 0.001 in untreated vs complete response patients). IgA levels were high in some untreated patients and lower in complete response patients. IgE levels were increased in some untreated and partial response patients, but there was no significant difference among the three groups. These results suggested that the hypergammaglobulinemia found in HIV infected patients was associated with HIV replication. The activation mechanism might differ by Ig isotypes.

Green tea catechins enhance tumor development in the colon without effects in the lung or thyroid after pretreatment with 1,2-Dimethylhydrazine or 2,2′-dihydroxy-di-n-propylnitrosamine in male F344 rats

Modifying effects of green tea catechins (GTCs) on the post-initiation stage of colon, lung and thyroid carcinogenesis were examined in F344 male rats. Groups of 20 animals were given subcutaneous injections of 40 mg/kg body wt of 1,2-dimethylhydrazine twice a week for 2 weeks or oral administration of 0.1% 2,2'-dihydroxy-di-n-propylnitrosamine (DHPN) in the drinking water for 2 weeks for initiation. They then received diet containing 1 or 0.1% green tea catechin or basal diet alone for 33 weeks. Histopathological examination after final sacrifice showed that although total incidence and multiplicity of colon tumors were not significantly different from controls, values for colon adenomas were decreased while those for carcinomas and the average size of tumors were significantly increased in the 0.1% GTC group. A similar tendency was observed for the 1% GTC group. Incidences and/or multiplicity of lung hyperplasia and tumors, and thyroid lesions did not significantly vary among the DHPN-treated groups. These results indicate that GTCs do not inhibit, but rather may enhance colon carcinogenesis, while not influencing lung and thyroid carcinogenesis under the present experimental conditions.

Site-dependent modulating effects of conjugated fatty acids from safflower oil in a rat two-stage carcinogenesis model in female Sprague–Dawley rats

Modifying effects of dietary administration of conjugated fatty acids from safflower oil (CFA-S), rich in conjugated linoleic acid, on major organs were examined in the post-initiation stage of a two-stage carcinogenesis model in female rats. Groups of 21 or 22 F344 female rats were treated sequentially with 2,2'-dihydroxy-di-n-propylnitosamine (intragastrically, i.g.), 7,12-dimethylbenz[a]anthracene (i.g.), 1,2-dimethylhydrazine (subcutaneously) and N-butyl-N-(4-hydroxybutyl)nitrosamine (in drinking water) during the first 3 weeks for initiation, and then administered diet containing 1 or 0.1% CFA-S for 33 weeks. Further groups of animals were treated with carcinogens or 1% CFA-S alone, or maintained as non-treated controls. All surviving animals were killed at week 36, and major organs were examined histopathologically for development of pre-neoplastic and neoplastic lesions. The 1 and 0.1% CFA-S treatment significantly decreased the incidence and multiplicity of mammary carcinomas, though a clear dose response was not observed. In the urinary bladder, the incidence of papillary or nodular hyperplasia but not tumors was significantly increased in the 1% CFA-S-treated group. The results indicate that low dose CFA-S may find application as a potent chemopreventor of mammary carcinogenesis.

Generalized Wegener's granulomatosis responding to sulfamethoxazole-trimethoprim monotherapy

Wegener's granulomatosis (WG) has two different clinical phases: the initial phase and generalized phase. In patients with generalized WG, both steroids and cyclophosphamide have generally been used. We report a case of generalized WG that was temporarily, but successfully treated with sulfamethoxazole-trimethoprim (S/T) alone. S/T therapy reduced the elevated levels of soluble IL-2 receptor and IL-6 in parallel with improvement of the patient's symptoms and urinary protein excretion. In view of the high incidence of lethal adverse effects of cytotoxic drugs, S/T monotherapy may be worth trying not only for initial phase WG but also for generalized WG with careful follow-up when the patient is not acutely ill.

Thermostabilization by replacement of specific residues with lysine in a Bacillus alkaline cellulase: building a structural model and implications of newly formed double intrahelical salt bridges

An alkaline, mesophilic endo-1,4-beta-glucanase from alkaliphilic Bacillus sp. strain KSM-64 was significantly thermostabilized by replacement of both Asn179 and Asp194 with lysine by site-directed mutagenesis. Structural remodeling of the mutant enzyme newly generated by the double mutation suggested that Glu175-->Lys179 and Glu190-->Lys194 were the most plausible ion pairs, both of which involved side chains at the i and i + 4 positions on the alpha(4)-helix from Glu175 to Ser195. By molecular dynamics simulations, the N(zeta) hydrogens of Lys179 and Lys194 were found to coordinate with the carbonyl O(varepsilon1) and O(varepsilon2) of Glu175 and the carbonyl O(varepsilon1) of Glu190, respectively, with distances of around 2 A for all. These results confirm that the formation of these double intrahelical ion pairs (salt bridges) is responsible for the thermostabilization by the double mutation.

Prostate carcinomas developing in transgenic rats with SV40 T antigen expression under probasin promoter control are strictly androgen dependent

We have generated a transgenic rat with the SV40 T antigen under probasin promoter control, allowing prostate-specific gene expression. Males demonstrate atypical epithelial cell proliferation in the prostate from 4 weeks of age and develop prostate carcinomas at 100% incidence before they are 15 weeks old. Castration at 5 weeks of age was found to inhibit the prostate tumor formation completely, whereas testosterone propionate administration induced marked cell proliferation as well as microinvasion in prostate carcinomas. Castration at 20 weeks of age, after tumor development, even with testosterone propionate treatment, induced complete tumor involution within 5 weeks. To investigate the underling processes, sequential histological changes were monitored 1, 2, 3, 7, 14, and 21 days after castration. At days 1-3, many apoptotic bodies and inflammatory cells, including foam cells, were observed, and clear glandular structures were no longer evident in the tumors. Seven days after castration, most glands were involved, and nuclei of the cells did not show atypia. After 14 and 21 days, only atrophic glands were observed. During this process, expression of caspase 3, caspase 6, BAX, bcl-x, TRPM-2, and MMP7 genes was apparently increased. Comparison of the gene expression profile between a prostate carcinoma in a transgenic animal and a normal prostate of a wild-type rat by a cDNA array technique was also conducted. The results suggested that our model is suitable to investigate mechanisms of carcinogenesis, including androgen dependence, involution, and apoptosis.

Effects of hemoglobin on pulmonary arterial pressure and pulmonary vascular resistance in patients with chronic emphysema

BACKGROUND

The increase in viscosity caused by secondary polycythemia is thought to be one of the major causes of pulmonary hypertension secondary to chronic emphysema. However, very few clinical studies considered the relation between pulmonary hypertension and polycythemia in the case of chronic obstructive pulmonary disease.

OBJECTIVE

The purpose of this study is to elucidate the relative contribution of an increase in hemoglobin level (Hb) to mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR).

METHODS

We retrospectively investigated 41 patients with chronic emphysema who had undergone a right heart catheterization. Multiple-regression analysis and F test were performed to investigate both direct effects of Hb and PaO(2) as independent variables on mPAP and PVR as dependent variables.

RESULTS

Significant correlations were found between PaO(2) and mPAP (or PVR), or Hb and mPAP (or PVR), indicating that both Hb and PaO(2) are contributory to mPAP and PVR. The F test demonstrated that Hb and PaO(2) could directly affect the level of either mPAP or PVR.

CONCLUSIONS

It was concluded that Hb had a direct effect on mPAP and PVR, independently of hypoxia in patients with chronic emphysema.

Metastasizing neuroblastomas from taste buds in rats transgenic for the Simian virus 40 large T antigen under control of the probasin gene promoter

During establishment of a prostate cancer model in rats transgenic for the Simian virus 40 large T antigen, under control of the probasin gene promoter, with protein expression specific to the prostate, tongue, and spinal cord, undifferentiated small round cell tumors were frequently observed. Extensive examination of tongues of the transgenic rats, despite a macroscopically normal appearance, revealed the tumors to have come from taste buds of the papilla circumvallata and papilla foliata. The lesions were positive for the SV40 T antigen, PGP9.5 (ubiquitin C-terminal hydrolase), and synaptophysin, neuron and neuroendocrine markers. Morphologically and immunohistochemically, the tumors were diagnosed as neuroblastomas, considering the neuroepithelial origin. Histologically identical tumor cells in the spinal cord and lung were observed only in the rats with deeply invading tongue tumors, suggesting that metastasis from the tongue tumors had occurred. Castration or supplementation with testosterone propionate did not alter tumor development, indicating the tumors to be androgen-independent. These results clearly show that taste buds can give rise to metastasizing neuroblastomas.

[A-56-year-old woman with parkinsonism, whose mother had Parkinson's disease]

We report a 56-year-old woman with progressive gait disturbance. Her mother had Parkinson's disease with onset at age 70. She died at age 74 and the post-mortem examination confirmed the diagnosis of Lewy body positive Parkinson's disease. The patient was well until the age of 50(1995) when she noted an onset of resting tremor and difficulty of gait. She also developed delusional ideation and was admitted to a psychiatric service of another hospital, where a major tranquilizer was given. The delusion disappeared but she developed marked rigidity. The major tranquilizer was discontinued and an anticholinergic and amantadine HCl were given. She showed marked improvement to Hoehn and Yahr stage II and was discharged. In 1995, when she was 52 years of the age, she developed delusion again and a major tranquilizer was given. She developed marked parkinsonism again and became Hoehn and Yahr stage V. The major tranquilizer was discontinued and she was treated with levodopa/carbidopa, trihexyphenidyl, bromocriptine, and dops. She improved remarkably to stage II. She was admitted to our service on October 8, 1996 for drug adjustment. She was alert and not demented. She was anxious but delusion or hallucination was noted. Higher cerebral functions were intact. Cranial nerve functions were also intact except for masked face and small voice. Her posture was stooped and steps were small. She showed retropulsion and moderate bradykinesia. Resting tremor was noted in her left hand. Rigidity was noted in both legs. No cerebellar ataxia or weakness was noted. Deep tendon reflexes were within normal range and sensation was intact. Her cranial MRI revealed some atrophic changes in the putamen, in which a T 2-high signal linear lesion was seen along the lateral border of the putamen bilaterally. In addition, posterior part of the putamen showed T 2-low signal intensity change. She was treated with 1.6 mg of talipexole, 6 mg of trihexyphenidyl, and 100 mg of L-dops. She was in stage III of Hoehn and Yahr. She developed neurogenic bladder with a large amount of residual urine for which she required catheterization. She was transferred to another hospital. Despite drug adjustment, she lost response to levodopa and her parkinsonism deteriorated gradually. She also developed syncope orthostatic hypotension. In April of 1998, she developed intracerebral hemorrhage and was admitted again on April 19, 1998. She was unable to stand and showed marked akinesia and rigidity. She was in stage V of Hoehn and Yahr. Her cranial CT scan revealed bilateral high-density lesions in the posterior parietal lobes. She developed dysphagia for which she required gastrostomy. She was transferred to another hospital but her clinical condition deteriorated further. On December 22, 1999, she developed fever and dyspnea and was admitted to our service again. She developed cardial arrest at the emergency room from hypoxia. She was resuscitated; however, she was comatose with loss of brain stem reflexes. Later on she developed generalized myoclonus. She developed cardiac arrest and pronounced dead on December 28, 1999. The patient was discussed in a neurological CPC. The chief discussant arrived at the conclusion that the patient had striatonigral degeneration because of poor response to levodopa in the later course, autonomic failures, and MRI changes. Some other participants thought that the patient had a form of familial Parkinson's disease. Opinions were divided into these two possibilities. Post-mortem examination revealed that the substantia nigra showed intense neuronal loss and gliosis, however, no Lewy bodies were seen. In addition, intracytoplasmic inclusions were seen in oligodendrocytes. The putamen was markedly atrophic in its posterior part with marked gliosis and neuronal loss. The ventromedial part of the pontine nucleus also showed neuronal loss and intracytoplasmic glial inclusions. Pathologic diagnosis was multiple system atrophy. In the parietal lobe, an arteriovenous malformation with bleeding was noted. This is very unique case. Although her mother had Lewy body-positive Parkinson's disease, the patient had Lewy body-negative multiple system atrophy with a-synuclein-positive glial inclusions. Whether this is just a coincidental occurrence or the presence of a genetic load for Parkinson's disease might triggered her multiple system atrophy is an interesting question to be answered in future.

Establishment of rat hepatocellular carcinoma cell lines with differing metastatic potential in nude mice

For better understanding of cancer metastasis, we have established an in vivo model for induction of highly metastatic hepatocellular carcinomas (HCC) in male F344 rats. From 1 tumor, 4 cell lines with differing metastatic potential (C1, C2, C6, C5F) were established by subcloning using the limited-dilution cloning technique. Two other lines, N1 and L2, arose from another primary HCC and a lung metastatic lesion, respectively. Although cell adhesion of each cell line in culture medium was different, tumors developing in the subcutis of nude mice after transplantation were all moderately differentiated HCC with a trabecular pattern. On subcutaneous injection into nude mice, all 6 cell lines proved to be tumorigenic in the injection site and C5F was highly metastatic to the lung. With injection into the tail vein, N1 and L2 formed frequent metastases in the lung as well as in lymph nodes. Using intraperitoneal injection, C1, C6, N1 and L2 showed marked disseminated growth in the abdominal cavity with bloody ascitis. Northern blot analysis revealed expression of known metastasis-related genes, KAI1 and heparanase, to be decreased in C5F, but no differences in expression of nm23-H1 were evident. A point mutation in the GSK-3beta phosphorylation site of the beta-catenin gene was found in L2. These transplantable HCC cell lines that have different metastatic ability should be useful for elucidation of mechanisms of metastasis.

Establishment of rat hepatocellular carcinoma cell lines with differing metastatic potential in nude mice

For better understanding of cancer metastasis, we have established an in vivo model for induction of highly metastatic hepatocellular carcinomas (HCC) in male F344 rats. From 1 tumor, 4 cell lines with differing metastatic potential (C1, C2, C6, C5F) were established by subcloning using the limited-dilution cloning technique. Two other lines, N1 and L2, arose from another primary HCC and a lung metastatic lesion, respectively. Although cell adhesion of each cell line in culture medium was different, tumors developing in the subcutis of nude mice after transplantation were all moderately differentiated HCC with a trabecular pattern. On subcutaneous injection into nude mice, all 6 cell lines proved to be tumorigenic in the injection site and C5F was highly metastatic to the lung. With injection into the tail vein, N1 and L2 formed frequent metastases in the lung as well as in lymph nodes. Using intraperitoneal injection, C1, C6, N1 and L2 showed marked disseminated growth in the abdominal cavity with bloody ascitis. Northern blot analysis revealed expression of known metastasis-related genes, KAI1 and heparanase, to be decreased in C5F, but no differences in expression of nm23-H1 were evident. A point mutation in the GSK-3beta phosphorylation site of the beta-catenin gene was found in L2. These transplantable HCC cell lines that have different metastatic ability should be useful for elucidation of mechanisms of metastasis.

Lineage switch induced by overexpression of Ets family transcription factor PU.1 in murine erythroleukemia cells

PU.1 is an Ets family transcription factor essential for myelomonocyte and B-cell development. We previously showed that overexpression of PU.1 in murine erythroleukemia (MEL) cells inhibits growth and erythroid differentiation and induces apoptosis of the cells. In an effort to identify target genes of PU.1 concerning these phenomena by using a messenger RNA differential display strategy, we found that some myeloid-specific and lymphoid-specific genes, such as the osteopontin gene, are transcriptionally up-regulated in MEL cells after overexpression of PU.1. We then found that expression of several myelomonocyte-specific genes, including the CAAT-enhancer-binding protein-alpha and granulocyte-macrophage colony-stimulating factor receptor genes, was induced in MEL cells after overexpression of PU.1. B-cell-specific genes were also examined, and expression of the CD19 gene was found to be induced. Expression of the myelomonocyte-specific proteins CD11b and F4/80 antigen but not the B-cell-specific proteins B220 and CD19 was also induced. After overexpression of PU.1, MEL cells became adherent and phagocytic and showed enhanced nitroblue tetrazolium reduction activity. Expression of myelomonocyte-specific and B-cell-specific genes was not induced when a mutant PU.1 with part of the activation domain deleted (a change found to inhibit erythroid differentiation of MEL cells) was expressed. These results indicate that PU.1 induces a lineage switch in MEL cells toward myelomonocytic cells and that its activation domain is essential for this effect. The results also suggest that the pathway of the lineage switch is distinct from that of inhibition of erythroid differentiation in MEL cells.

Observation of vacuum-ultraviolet Kr(2)* laser oscillation pumped by a compact discharge device

We have demonstrated vacuum-ultraviolet (VUV) Kr(2) * laser oscillation as a result of the realization of a stable self-sustained discharge of high-pressure Kr by use of a compact discharge device. Glow discharge was obtained with as much as 10 atm of pure Kr. The VUV emission intensity centered at 147.8 nm abruptly increased when the charging voltage exceeded a certain value. In addition to this threshold behavior, considerable spectral narrowing (4.0?0.4 nm) was observed when the charging voltage increased. The maximum output energy at 148 nm was 150muJ . The gain coefficient was estimated to be 1.1% cm (-1) .

Reactivity of anti-proliferating cell nuclear antigen (PCNA) murine monoclonal antibodies and human autoantibodies to the PCNA multiprotein complexes involved in cell proliferation

Proliferating cell nuclear Ag (PCNA) occurs as a component of multiprotein complexes during cell proliferation. We found the complexes to react with murine anti-PCNA mAbs, but not with anti-PCNA Abs in lupus sera. The complexes were purified from rabbit thymus extract by affinity chromatography using anti-PCNA mAbs (TOB7, TO17, and TO30) and analyzed by ELISA, immunoprecipitation, immunoblotting, and HPLC gel filtration. That PCNA was complexed with other proteins was demonstrated by its copurification with a group of proteins excluded by an HPLC G3000 SW column. Although immunoblot analysis showed the mAbs to react exclusively with the 34-kDa PCNA polypeptide, they nonetheless immunoprecipitated the same group of proteins, confirming the interaction of the isolated PCNA with other proteins. Anti-PCNA sera, including AK, which reacts with biologically functional sites on PCNA, did not react with complexed PCNA, but did react with it once it was dissociated from the complexes. PCNA complexes in turn reacted with murine anti-DNA mAbs, as well as with Abs against p21, replication protein A, DNA helicase II, cyclin-dependent kinases 4 and 5, and topoisomerase I. These findings suggest that the PCNA complexes purified using anti-PCNA mAbs comprise the "protein machinery" for DNA replication and cell cycle regulation. They also suggest that anti-PCNA mAbs are useful tools with which to characterize the protein-protein interactions within PCNA complexes, as well as the autoimmune responses to proteins interacting with PCNA, which may shed light on the mechanisms of autoantibody production in lupus patients.

Epidemiology and etiology of premalignant and malignant urothelial changes

Bladder neoplasms are common around the world. Incidences are particularly high in the Nile River Valley secondary to schistosomiasis, which is frequently associated with the development of squamous cell carcinoma similar to that of other chronic inflammatory processes of the lower urinary tract. However, elsewhere, most bladder tumors are of the urothelial (transitional) cell type. There is a marked male predominance and there are extensive racial differences. It is predominantly a neoplasm that occurs in patients aged >50 years. Urothelial carcinomas comprise two distinct diseases both biologically and molecularly: a low-grade papillary tumor which frequently recurs; and a high-grade malignancy which can present as dysplasia or carcinoma in situ, but frequently presents as invasive disease. However, epidemiological investigations of urothelial malignancies have generally not distinguished between preneoplastic and invasive neoplasms or between these two types of urothelial neoplasms. It is recommended that future studies should distinguish between these entities. The most common etiologic factor of urothelial malignancies besides schistosomiasis is cigarette smoking. In addition, numerous specific chemicals have been identified as bladder carcinogens in humans, some relating to specific occupational exposures. Bladder carcinogens include aromatic amines and amides, such as 4-aminobiphenyl, benzidine, 2-naphthylamine and phenacetin-containing analgesics, and certain cancer chemotherapeutic agents, such as phosphoramide mustards. More recently, occupational exposure to various combustion gases, such as diesel exhaust, has been related to an increased risk of developing bladder neoplasms. Also, exposure to chlorination by-products in drinking water and to arsenic has been suggested as increasing the risk of bladder neoplasia. As numerous specific chemicals appear to be related to the development of bladder tumors, various polymorphisms of enzymes involved in their metabolism have been suggested as affecting the susceptibility to their carcinogenicity. This has been particularly true with respect to the role of acetyltransferases in relation to aromatic amine carcinogenesis. Dietary influences have also been suggested as affecting bladder neoplasia susceptibility. Various heterocyclic amines generated by pyrolysis of food have been suggested as potential dietary factors increasing the risk of bladder cancer, particularly in relation to the ingestion of red meat. Despite the existence of several identifiable factors that increase or decrease the risk of bladder cancer, many patients have no known carcinogens or risk factors.

Establishment of rat hepatocellular carcinoma cell lines with differing metastatic potential in nude mice

For better understanding of cancer metastasis, we have established an in vivo model for induction of highly metastatic hepatocellular carcinomas (HCC) in male F344 rats. From 1 tumor, 4 cell lines with differing metastatic potential (C1, C2, C6, C5F) were established by subcloning using the limited-dilution cloning technique. Two other lines, N1 and L2, arose from another primary HCC and a lung metastatic lesion, respectively. Although cell adhesion of each cell line in culture medium was different, tumors developing in the subcutis of nude mice after transplantation were all moderately differentiated HCC with a trabecular pattern. On subcutaneous injection into nude mice, all 6 cell lines proved to be tumorigenic in the injection site and C5F was highly metastatic to the lung. With injection into the tail vein, N1 and L2 formed frequent metastases in the lung as well as in lymph nodes. Using intraperitoneal injection, C1, C6, N1 and L2 showed marked disseminated growth in the abdominal cavity with bloody ascitis. Northern blot analysis revealed expression of known metastasis-related genes, KAI1 and heparanase, to be decreased in C5F, but no differences in expression of nm23-H1 were evident. A point mutation in the GSK-3beta phosphorylation site of the beta-catenin gene was found in L2. These transplantable HCC cell lines that have different metastatic ability should be useful for elucidation of mechanisms of metastasis.

Lack of chemopreventive effects of lycopene and curcumin on experimental rat prostate carcinogenesis

The chemopreventive efficacy of lycopene and curcumin with regard to prostate carcinogenesis was investigated using 3,2'-dimethyl-4-aminobiphenol (DMAB)- and 2-amino-1-methylimidazo[4,5-b]pyridine (PhIP)-induced rat ventral prostate cancer models. Three 60 week experiments with male F344 rats were carried out. In the first DMAB was given for the first 20 weeks and lycopene or curcumin were administered concomitantly or subsequently at dietary doses of 15 and 500 p.p.m., respectively. In the second experiment lycopene and curcumin were given to rats pretreated with DMAB at doses of 5, 15 or 45 p.p.m. or 100 or 500 p.p.m. In the third PhIP was selected as an initiator for prostate carcinogenesis and administered for 20 weeks. Rats were then fed a diet containing lycopene at a dose of 45 p.p.m. or curcumin at a dose of 500 p.p.m. or both together. Chemopreventive effects of lycopene and curcumin on development of DMAB-induced ventral prostate carcinomas were observed only in the first experiment and no confirmation of inhibition potential was obtained in the following studies. Neither summational nor synergistic chemoprevention was evident. It is concluded from the present data that, overall, neither lycopene nor curcumin can consistently prevent rat prostate carcinogenesis.

Dose-dependent induction of glandular stomach preneoplastic and neoplastic lesions in male F344 rats treated with catechol chronically

The dose-dependence of catechol glandular stomach carcinogenesis was investigated in male F344 rats. Groups of 30 male animals were fed catechol at dietary levels of 0 (control). 0.1, 0.2, 0.4, and 0.8% for up to 104 weeks. Five rats of each group were killed at 34 weeks and the remaining animals were sacrificed at the termination, all undergoing histopathological examination. Moderate retardation of body weight increase was observed in the 0.8% group. but no adverse effects were found in terms of survival. Submucosal hyperplasias and adenomas of the pyloric glands developed in the 0.4 and 0.8% groups, only very minor changes being noted in the 0.1 and 0.2% groups at week 34. Incidences of adenocarcinoma development in the pylorus were 4% and 8% in 0.4% and 0.8% groups, respectively, and 0 in the 0.1% and 0.2% groups, at the termination. Adenomas and submucosal hyperplasias were found in nearly all animals fed 0.2% catechol or more, the incidences of those in 0.1% group being 0% and 56%, respectively. Serum gastrin levels were significantly increased in the 0.2, 0.4, and 0.8% groups at 34 weeks, and in all treated groups at the termination, at extents comparable with the induction of proliferative lesions in the pylorus. The results thus demonstrated that dietary levels of 0.4% and 0.8% catechol long-term induce adenocarcinomas in the pyloric glands, while 0.1 and 0.2% cause benign proliferative lesions, all accompanied by increase in serum gastrin levels. As a no-effect level could not be decided in the present study, further investigation of lower doses is needed to determine whether a threshold exists.

Autoantibody responses to cardiolipin and DNA in infancy: association with lymphocytic panniculitis

We report an infant with anticardiolipin (aCL) antibodies who presented with erythematous nodular skin lesions and elevated liver enzyme levels. The cutaneous manifestation was histologically lymphocytic lobular panniculitis with vasculitic and hemorrhagic changes. The infant also had low levels of anti-double stranded DNA (dsDNA) and anti-single stranded DNA (ssDNA) antibodies. There were no detectable antibodies to small nuclear ribonucleoproteins including Ro/SSA and La/SSB. His mother was consistently seronegative for any of these antibodies. Without corticosteroid therapy, cutaneous lesions resolved and anticardiolipin antibodies, but not anti-dsDNA and ssDNA antibodies, normalized within 16 months after the onset of the disease. Our patient demonstrated an uncommon presentation of aCL related cutaneous manifestation, the presentation with panniculitis being only the third such patient reported in the literature. Of great interest was the appearance of aCL antibodies and skin lesions during very early infancy.

Genetic aspects of inherent B-cell abnormalities associated with SLE and B-cell malignancy: lessons from New Zealand mouse models

Genes that predispose to SLE are closely related to key events in pathogenesis of this disease. As much of the pathology can be attributed to high affinity autoantibodies and/or their immune complexes, some of the genes may exert effects in the process of emergence, escape from tolerance mechanisms, activation, clonal expansion, differentiation, class switching and affinity maturation of self-reactive B cells. A number of growth and differentiation factors and signaling molecules, including positive and negative regulators, are involved in this process. Genetic variations associated with functional deficits in some of such molecules can be involved in the susceptibility for SLE. As is the case with SLE, hereditary factors play significant roles in the pathogenesis of B cell chronic lymphocytic leukemia (B-CLL). Patients with B-CLL or their family members frequently have immunological abnormalities, including those associated with SLE. It is suggested that certain genetically determined regulatory abnormalities of B cells may be a crossroad between B-CLL and SLE. A thorough understanding of the genetic pathways in B cell abnormalities leading to either SLE or B-CLL is expected to shed light on their association. New Zealand mouse strains are pertinent laboratory models for these studies. Chromosomal locations of several major genetic loci for abnormal proliferation, differentiation and maturation of B cells and relevant candidate genes, located in close proximity to these intervals and potentially related to the SLE pathogenesis, have been identified in these mice. Further studies make for a wider knowledge and understanding of the pathogenesis of SLE and related B-cell malignancy.

Preface and overview: genetics of SLE; a sine qua non for identification

Clinical manifestations of systemic lupus erythematosus (SLE) are extremely diverse and variable, mainly because SLE is a multi-factorial disease. Variable combinations of contributing genes at multiple loci in individual patients probably result in diverse disease phenotypes. Genes that predispose to SLE are undoubtedly related to key events in pathogenesis, and may involve a variety of genes in immune system. These genes are currently unidentified, mostly because of the complexity of multi-factorial inheritance. Recently, the application of the polymerase chain reaction and the availability of maps of microsatellites have facilitated a genome-wide scan to define the number and locations of genes for complex traits. However, extensive genetic heterogeneities and polymorphisms and complex modes of inheritance of disease phenotypes have delayed completion of a genome-wide analysis of susceptibility loci for human SLE. Since many SLE-susceptibility genes show low penetrance, several hundred affected sibpairs are assumed to be necessary to show linkages for many of the contributing loci. In this respect, studies of polymorphisms and functions of candidate genes suggested based on studies on murine models may contribute to studies on SLE patients and their relatives. Major genetic loci have been mostly identified in SLE-prone mouse strains. Nevertheless, identity of natures, functions and roles in the pathogenesis of SLE remains undetermined. Considering the possibility of clustering of susceptibility loci in a particular chromosomal interval, the final goal for identification of susceptibility genes will largely depend on the generation of mutant SLE-prone mice with homologous recombination of the potential target gene. Extensive reviews collected here are expected to form the basis for identification of target genes and for clarification of the genetic mechanisms underlying SLE.

Frequent c-Ha-ras gene mutations in rat mammary carcinomas induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most abundant heterocyclic amine in cooked meat and fish, is carcinogenic to the mammary glands of rats. Mutations in the H-ras gene were here examined in PhIP-induced mammary tumors of female F344 rats by the polymerase chain reaction followed by single strand conformation polymorphism analysis (PCR-SSCP) and restriction enzyme length polymorphism analysis (RFLP). Mutations in codon 12 of the H-ras gene were detected in four out of 13 tumors by PCR-SSCP. Three of them were GGA to GAA, and one was GGA to GTA. However, by RFLP analysis, four additional mutations in codon 13 were also detected in the same samples. Two had a GGC to CGC mutation, and the other shifts were GGC to GAC and GGC to GTC. Therefore, overall eight out of 13 cases had H-ras gene mutations. These results indicate that changes in H-ras function may play important roles in PhIP-induced mammary carcinogenesis.

Membrane recruitment of DOCK180 by binding to PtdIns(3,4,5)P3

DOCK180 was originally identified as one of two major proteins bound to the Crk oncogene product and became an archetype of the CDM family of proteins, including Ced-5 of Caenorhabditis elegans and Mbc of Drosophila melanogaster. Further study has suggested that DOCK180 is involved in the activation of Rac by the CrkII-p130(Cas) complex. With the use of deletion mutants of DOCK180, we found that the C-terminal region containing a cluster of basic amino acids was required for binding to and activation of Rac. This region showed high amino-acid sequence similarity to the consensus sequence of the phosphoinositide-binding site; this led us to examine whether this basic region binds to phosphoinositides. For this purpose we used PtdIns(3,4,5)P(3)-APB beads, as reported previously [Shirai, Tanaka, Terada, Sawada, Shirai, Hashimoto, Nagata, Iwamatsu, Okawa, Li et al. (1998) Biochim. Biophys. Acta 1402, 292-302]. By using various competitors, we demonstrated the specific binding of DOCK180 to PtdIns(3,4,5)P(3). The expression of active phosphoinositide 3-kinase (PI-3K) did not enhance a DOCK180-induced increase in GTP-Rac; however, the expression of PI-3K translocated DOCK180 to the plasma membrane. Thus DOCK180 contained a phosphoinositide-binding domain, as did the other guanine nucleotide exchange factors with a Dbl homology domain, and was translocated to the plasma membrane on the activation of PI-3K.