Involvement of the Thalamus, Hippocampus, and Brainstem in Hypsarrhythmia of West Syndrome: Simultaneous Recordings of Electroencephalography and fMRI Study.

BACKGROUND AND PURPOSE: West syndrome is a developmental and epileptic encephalopathy characterized by epileptic spasms, neurodevelopmental regression, and a specific EEG pattern called hypsarrhythmia. Our aim was to investigate the brain activities related to hypsarrhythmia at onset and focal epileptiform discharges in the remote period in children with West syndrome using simultaneous electroencephalography and fMRI recordings. MATERIALS AND METHODS: Fourteen children with West syndrome underwent simultaneous electroencephalography and fMRI at the onset of West syndrome. Statistically significant blood oxygen level-dependent responses related to hypsarrhythmia were analyzed using an event-related design of 4 hemodynamic response functions with peaks at 3, 5, 7, and 9 seconds after the onset of each event. Six of 14 children had focal epileptiform discharges after treatment and underwent simultaneous electroencephalography and fMRI from 12 to 25 months of age. RESULTS: At onset, positive blood oxygen level-dependent responses were seen in the brainstem (14/14 patients), thalami (13/14), basal ganglia (13/14), and hippocampi (13/14), in addition to multiple cerebral cortices. Group analysis using hemodynamic response functions with peaks at 3, 5, and 7 seconds showed positive blood oxygen level-dependent responses in the brainstem, thalamus, and hippocampus, while positive blood oxygen level-dependent responses in multiple cerebral cortices were seen using hemodynamic response functions with peaks at 5 and 7 seconds. In the remote period, 3 of 6 children had focal epileptiform discharge-related positive blood oxygen level-dependent responses in the thalamus, hippocampus, and brainstem. CONCLUSIONS: Positive blood oxygen level-dependent responses with hypsarrhythmia appeared in the brainstem, thalamus, and hippocampus on earlier hemodynamic response functions than the cerebral cortices, suggesting the propagation of epileptogenic activities from the deep brain structures to the neocortices. Activation of the hippocampus, thalamus, and brainstem was still seen in half of the patients with focal epileptiform discharges after adrenocorticotropic hormone therapy.

Longitudinal Findings of MRI and PET in West Syndrome with Subtle Focal Cortical Dysplasia.

BACKGROUND AND PURPOSE: Despite the development of neuroimaging, identification of focal cortical dysplasia remains challenging. The purpose of this study was to show the longitudinal changes of MR imaging and FDG-PET in patients with West syndrome and subtle focal cortical dysplasia. MATERIALS AND METHODS: Among 52 consecutive patients with West syndrome, 4 were diagnosed with subtle focal cortical dysplasia on 3T MR imaging. MR imaging and PET findings were evaluated longitudinally at onset and at 12 and 24 months of age. RESULTS: At the onset of West syndrome, MR imaging demonstrated focal signal abnormalities of the subcortical white matter in 2 patients. In the other 2 patients, focal subcortical high-intensity signals became visible on follow-up T2WI as myelination progressed. PET at onset showed focal cortical hypometabolism in 3 patients, with 1 of these patients also having focal hypermetabolism and 1 having normal findings. On PET at 24 months, hypometabolism persisted in 2 patients and disappeared in 1, and hypermetabolism disappeared in 1. In 1 patient with normal MR imaging and PET findings at onset, focal hyperintensity and hypometabolism first appeared at 24 months of age. The findings on MR imaging and PET in these patients evolved differently with brain maturation and the clinical course. CONCLUSIONS: Subtle focal cortical dysplasia can be undetectable on MR imaging at the onset of West syndrome and is not always accompanied by hypometabolism or hypermetabolism on PET. Longitudinal MR imaging and PET studies may be useful for detecting such lesions. Even in West syndrome with a congenital structural abnormality, PET findings evolve differently with brain maturation and the clinical condition.

Identification and antioxidant activity of several pigments from the residual green tea (Camellia sinensis) after hot water extraction.

Antioxidant activity of green tea extract or tea-derived polyphenols has been extensively studied. However, antioxidant activity in the non-polyphenolic fraction of green tea has been poorly analyzed. In the present study, we analyzed the antioxidant activity of the non-polyphenolic fraction of the residual green tea (Camellia sinensis) after hot water extraction using the aluminum chloride method. The non-polyphenolic fraction of residual green tea caused a significant suppression against hydroperoxide generation from oxidized linoleic acid in a dose-dependent manner. When the concentrate of the non-polyphenolic fraction was applied to a silica gel TLC plate and developed, six color spots were observed, which were considered to be chlorophylls a and b, pheophytins a and b, carotenoids, such as beta-carotene and lutein according to their specific colors, Rf values of silica gel TLC and spectrophotometric properties. Among these pigments, pheophytins a and b showed relatively abundant amounts, and the second major group of the pigment was chlorophylls a and b, and carotenoids such as beta-carotene and lutein indicated lower concentrations. Although all these pigments exhibited significant antioxidant activities, the ranks of suppressive activity against hydroperoxide generation were chlorophyll a > lutein > pheophytin a > chlorophyll b > beta-carotene > pheophytin b. These results suggest that the non-polyphenolic fraction of residual green tea has a potent suppressive activity against hydroperoxide generation from oxidized linoleic acid, which is derived from the antioxidant activities of chlorophylls a and b, pheophytins a and b, beta-carotene and lutein. This finding also implies that the combined intake of polyphenols in water-soluble fraction and antioxidative pigments in the non-polyphenolic fraction of green tea will be more efficient to prevent life style-related chronic diseases.

Molecular analysis of multidrug resistance in feline lymphoma cells.

OBJECTIVE: To evaluate the mechanism of multidrug resistance in feline lymphoma cell lines. SAMPLE POPULATION: A feline lymphoma cell line (FT-1) and its adriamycin (ADM)-resistant subline (FT-1/ADM). PROCEDURES: The FT-1 cell line was cultivated in the presence of a gradually increasing concentration of ADM to generate its ADM-resistant subline (FT-1/ADM). Susceptibility of cells from the parental FT-1 cell line and the FT-1/ADM subline to antineoplastic drugs was determined. From the complementary DNA (cDNA) template of FT-1/ADM cells, feline MDR1 cDNA was amplified by use of polymerase chain reaction (PCR) and sequenced. Reverse transcription (RT)-PCR and Western blot analyses were performed to assess expression of the MDR1 gene and P-glycoprotein (P-gp) in FT-1/ADM cells, compared with that in FT-1 cells. RESULTS: A drug sensitivity assay revealed that FT-1/ADM cells were much more resistant to ADM and vincristine than the parental FT-1 cells. The feline MDR7 cDNA amplified by use of PCR was 3,489 base pairs long, corresponding to approximately 90% of the whole open reading frame of human MDR1 cDNA; its amino acid sequence was 91.5, 87.0, and 79.4% identical to that of human MDR1, mouse mdr1a, and mdr1b cDNA, respectively. By RT-PCR analysis, expression of MDR1 messenger RNA was clearly detected in FT-1/ADM cells but not in the parental FT-1 cells. Western blot analysis also revealed the expression of P-gp encoded by the MDR1 gene in FT-1/ADM cells but not in FT-1 cells. CONCLUSIONS: The basic structure of the feline MDR1 gene was essentially the same as that of multidrug-resistance genes of other species. Expression of P-gp appeared to be one of the mechanisms responsible for the development of multidrug resistance in feline lymphoma cell lines in vitro.

Protective effects of alpha-tocopherol and beta-carotene on para-nonylphenol-induced inhibition of cell growth, cellular respiration and glucose-induced proton extrusion of bacteria.

para-Nonylphenol (NP) showed a dose-dependent inhibition against the cell growth of Bacillus subtilis, Micrococcus luteus, Pseudomonas aeruginosa and Staphylococcus aureus at 5-100 microM. However, other typical plastic-derived endocrine disruptors such as bisphenol A and di-2-ethylhexyl phthalate (DEHP) did not significantly affect the cell growth of these bacteria at 5-100 microM. The NP-induced cell growth inhibition was restored when concomitantly supplemented with lipophilic antioxidants such as alpha-tocopherol and beta-carotene, but not with hydrophilic antioxidants, ascorbic acid and (-)-epigallocatechin gallate (EGCG). NP also suppressed in a dose-dependent manner cellular oxygen consumption and glucose-induced proton extrusion of these bacteria at 10-100 microM. Both effects were prevented when added with alpha-tocopherol and beta-carotene, but not with ascorbic acid and EGCG. The significance of these results is discussed from the viewpoint of environmental microbiology and a possible biochemical mechanism of the inhibitory effect of NP is suggested.

Protective effect of antioxidants against para-nonylphenol-induced inhibition of cell growth in Saccharomyces cerevisiae.

The cell growth-modulating activity of an endocrine disruptor, p-nonylphenol (NP), was estimated using the yeast Saccharomyces cerevisiae as a simple model of eukaryotic cells. NP caused a dose-dependent suppressive effect on cell growth of S. cerevisiae at 10, 25 and 50 microM. The NP-induced cell growth inhibition was restored when concomitantly lipophilic antioxidants such as alpha-tocopherol and beta-carotene were supplied, but not the hydrophilic antioxidants ascorbic acid or (-)epigallocatechin gallate (EGCG). The cellular oxygen consumption of S. cerevisiae was also inhibited in a dose-dependent fashion by the extracellular addition of NP, and pretreatment with alpha-tocopherol and beta-carotene suppressed NP-induced inhibition of cellular oxygen consumption, but ascorbic acid and EGCG were not effective. Furthermore, NP caused a marked generation of radical oxygen species (ROS) in S. cerevisiae, which was suppressed by treatment with alpha-tocopherol and beta-carotene, but not with ascorbic acid and EGCG. However, NP did not show a significant inhibitory effect on cell growth and survival of mitochondria-deficient petite mutant cells and they showed a relatively weak ROS-generating activity compared with parent yeast cells. These results suggest that NP-induced inhibition of cell growth and oxygen consumption in S. cerevisiae might be possibly associated with ROS generation in yeast mitochondria. The significance of this finding is discussed from the viewpoint of NP-induced oxidative stress against eukaryotic cells.

Enhancing effect of a plastic plasticizer, di-2-ethylhexyl phthalate on umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002).

Di-2-ethylhexyl phthalate (DEHP) is the most extensively used phthalate ester as a plasticizer for plastic products made of polyvinyl chloride (PVC), and previous mutagenic and genotoxic studies have shown positive and negative results of DEHP-induced genotoxicity. To elucidate this discrepancy, we reestimated the genotoxicity of DEHP in more detail using the umu C gene expression system in Salmonella typhimurium (TA 1535/pSK 1002) which reflects SOS response against genotoxin-induced DNA damage. Although DEHP itself did not have a significant effect on umu C gene expression in tester bacteria at 0.5 to 4 mM, higher concentrations of DEHP (2 and 4 mM) caused a weak induction of umu C gene expression in the presence of commercially available S-9 mixture. Rat liver S-9 fraction alone also showed a similar weak inducing activity in the absence of substrates for drug-metabolizing enzymes. When DEHP was preincubated with S-9 fraction of various rat organs and applied to the umu C gene expression assay, S-9 fraction of rat pancreas had the strongest inducing activity, and S-9 fractions of liver and intestine homogenates showed weak but significant activities. However, S-9 fractions of lung and kidney homogenates did not exhibit any significant activities. These S-9 fractions have proportional lipase activities comparable with umu C gene expression activities. Furthermore, when DEHP was treated with highly purified lipase from porcine pancreas, a significant umu C gene expression was observed and this expression was enhanced in the presence of 1 or 5 mM bile acids such as choric acid and deoxychoric acid. These results suggest that DEHP itself has no or very low genotoxicity, but enzymatic and non-enzymatic factors in specific tissues induce DEHP-dependent genotoxic activity.

A simple estimation method for the embryonic toxicity of plastic wrapping sheets using an egg shell-free culture system of chick embryos.

To estimate the embryonic toxicity of food wrapping films, the shell-free chick embryos were cultured using plastic wrapping sheets like a suspending hammock. Polyethylene (PE) wrapping sheets with no additives showed much higher survivability than polyvinylchloride (PVC) wrapping sheets including plasticizers. Furthermore when a PVC wrapping sheet was autoclaved at 110 degrees C for 30 min, the embryonic survivability significantly decreased compared with the untreated PVC wrapping sheet. These observations suggest that the egg shell-free culture method using a plastic wrapping sheet is a useful estimation method for the embryonic toxicity of food wrapping film.

Inhibition of liver glutathione S-transferase placental form-positive foci development in the rat hepatocarcinogenesis by Porphyra tenera (Asakusa-nori).

The effects of Asakusa-nori, Porphyra tenera (PT), a popular edible seaweed in Japan, on the development of putative preneoplastic lesions, glutathione S-transferase placental form (GST-P)-positive foci, in the male F344 rat liver were examined using a medium-term bioassay system. PT significantly decreased both the number and area of GST-P-positive foci in rat livers initiated with diethylnitrosamine (DEN). To investigate possible mechanisms of inhibition, effects of PT on 5-bromo-2'-deoxyuridine (BrdU) labeling in GST-P-positive foci and the surrounding area of hepatocytes were studied. The ratio of the GST-P-positive foci to surrounding tissue labeling indices was decreased in the PT-treated group as compared with the DEN alone group. Ornithine decarboxylase activity in the liver was slightly increased and spermidine/spermine N'-acetyltransferase activity was slightly decreased in the PT-treated animals. These results suggest that PT possesses chemopreventive effects against DEN-induced hepatocarcinogenesis.

Potent suppressive effect of a Japanese edible seaweed, Enteromorpha prolifera (Sujiao-nori) on initiation and promotion phases of chemically induced mouse skin tumorigenesis.

Potent antigenotoxic and anti-tumor promoting activities of a Japanese edible seaweed, Enteromorpha prolifera (Sujiao-nori in Japanese) were previously identified using an in vitro cell culture experiment (Y. Okai, K. Higashi-Okai, S. Nakamura, Y. Yano, S. Otani, Cancer Lett. 87 (1994) 25-32). However, in vivo anti-carcinogenic activity of this seaweed has not been elucidated until now. In the present study, the anticarcinogenic activity of E. prolifera was analyzed using an initiation and promotion model experiment of mouse skin tumorigenesis caused by 7,12-dimethylbenz[a]anthracene (initiator) and 12-O-tetradecanoylphorbol-13-acetate (promoter). (1) Application of the extract of E. prolifera prior to the treatment with a tumor initiator or promoter caused a significant suppression against skin tumorigenesis, and the combined application of the extract prior to both treatments with initiator and promoter exhibited much stronger suppression against the same skin tumorigenesis. (2) As a possible active principle for the anticarcinogenic activity of the extract, we propose a chlorophyll-related compound, pheophytin-a, which has been recently identified in the extract of this alga as an antigenotoxic substance (Y. Okai, K. Higashi-Okai, J. Sci. Food Agric. 74 (1997) 531-535), and showed significant suppressive effects in the same tumorigenesis experiment. These results suggest that E. prolifera has a potent suppressive activity against chemically induced mouse skin tumorigenesis through the suppression at the initiation and promotion phases, and that pheophytin-a might be partially associated with the in vivo anticarcinogenic activity.

Potent suppressive activity of chlorophyll a and b from green tea (Camellia sinensis) against tumor promotion in mouse skin.

Potent antigenotoxic and anti-tumor promoting activities of chlorophyll a from green tea (camellia sinensis) have been shown using in vitro cell culture experiments (Okai Y. et al. (1996) Mutation Res., 370, 11-17). In the present study, the authors analyzed in vivo effects of chlorophyll a and b from green tea on tumor promotion in mouse skin in the following ways. 1. When chlorophyll a and b from green tea were applied before each treatment by a tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA) on BALB/c mouse skin initiated by 7, 12-dimethylbenz [a] an-thracene (DMBA), they caused significant suppression in a dose-dependent manner against BALB/c mouse skin tumorigenesis. 2. Chlorophyll a and b showed significant suppressive effects against TPA-induced inflammatory reaction such as edema formation in BALB/c mouse ear skin in a dose-dependent fashion. These results suggest that chlorophyll a and b possess potent suppressive activities against tumor promotion in mouse skin.

Potent suppressive activity of pheophytin a and b from the non-polyphenolic fraction of green tea (Camellia sinensis) against tumor promotion in mouse skin.

Chlorophyll-related compounds pheophytin a and b have been recently identified as antigenotoxic substances in the non-polyphenolic fraction of green tea (Camellia sinensis), which suppressed umu C gene expression in tester bacteria induced by various genotoxins (Okai and Higashi-Okai, Cancer Lett. 118 (1997) 117-123). In the present study, the authors analyzed in vivo and in vitro effects of pheophytin a and b from the non-polyphenolic fraction of green tea on tumor promotion in mouse skin as follows. (1) When pheophytin a and b from green tea were topically applied prior to each treatment with a tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA) on BALB/c mouse skin initiated by 7,12 dimethylbenz[a]anthracene (DMBA), they caused suppression in a dose-dependent fashion against skin tumorigenesis. (2) Pheophytin a and b exhibited significant suppressions against TPA-induced inflammatory reaction, such as edema formation, in BALB/c mouse ear skin in a dose-dependent manner. (3) Pheophytin a and b from green tea showed inhibitory effects against early induction of ornithine decarboxylase (ODC) in BALB/c mouse skin fibroblasts caused by TPA. These results suggest that pheophytin a and b from the non-polyphenolic fraction have potent suppressive activities against tumor promotion in mouse skin.

Potent anti-inflammatory activity of pheophytin a derived from edible green alga, Enteromorpha prolifera (Sujiao-nori).

Recently, a chlorophyll-related compound, pheophytin a, has been identified from an edible green alga, Enteromorpha prolifera (Sujiao-nori in Japanese) as a potent suppressive substance against genotoxin-induced umu C gene expression in a tester bacteria (Okai and Higashi-Okai, 1997, J. Sci. Food Agricul. 71, 531-535). In the present study, anti-inflammatory effects of pheophytin a from Enteromorpha prolifera have been analyzed using in vitro and in vivo experiments. 1. Pheophytin a suppressed the production of superoxide anion (O2-) in mouse macrophages induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) using the cytochrome C reduction method. 2. Pheophytin a caused a suppressive effect against formyl-Met-Leu-Phe, (FMLP)-induced chemotaxis of human polymorphonuclear leukocytes (PMNs) in Boyden's chamber experiment. 3. Pheophytin a exhibited a significant suppression against TPA-induced inflammatory reaction such as edema formation in BALB/c mouse ear. These results suggest that pheophytin a from Enteromorpha prolifera has a potent anti-inflammatory activity.

In vivo gene transfection of human endothelial cell nitric oxide synthase in cardiomyocytes causes apoptosis-like cell death. Identification using Sendai virus-coated liposomes.

BACKGROUND: Nitric oxide (NO) has various actions on the cardiovascular system, although its pathophysiological significance in myocardial cells remains obscure. The aim of the present study was to identify direct NO actions on cardiomyocytes by gene transfection in vivo using a newly developed vector under physiological conditions. METHODS AND RESULTS: Liposomes containing the beta-galactosidase (beta-gal) gene alone or with the human endothelial cell nitric oxide synthase (ecNOS) gene were coated with UV-inactivated Sendai virus and injected into the left ventricular wall of rat heart in vivo. Histological examination confirmed that the transfection efficiency was comparable to adenovirus-mediated transfection and that the new vector per se caused no inflammation. beta-Gal expression was confined to cardiomyocytes between two intercalated discs, suggesting that the transfected gene did not permeate the discs. An immunohistochemical study showed that cotransfection of the ecNOS gene induced massive myocardial cell shrinkage in both transfected cells and the adjacent myocytes in a time- and dose-dependent manner. Histochemical findings in shrunk cells coincided with apoptosis as identified by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling. Electron microscopy of the lesion revealed myofibrillar degradation and accumulation of mitochondria but no apoptotic bodies. Pre-treatment with the NOS inhibitor N omega-nitro-L-arginine methyl ester abolished these morphological alterations. CONCLUSIONS: The efficient expression of the human ecNOS gene in vivo suggests that NO or its toxic metabolite caused myocardial degradation, a part of which was compatible with apoptosis of the transfected cardiomyocytes themselves and the adjacent cells as a paracrine effect. These morphological features mimicked acute myocarditis or ischemic injury.

B cell stimulating activity of seaweed extracts.

The activity of seaweed extracts on murine and human lymphocytes was studied in vitro. The extracts of some kind of seaweed, such as Hizikia fusiformis and Meristotheca papulosa, stimulated normal mouse spleen cells to proliferate. The responder cells are B cells, because the response was depleted by the treatment of spleen cells with anti-immunoglobulin (Ig) antibody and complement and being passed through a nylon wool column. This response is not due to lipopolysaccharide (LPS) contamination, because seaweed extracts can stimulate spleen cells of C3H/HeJ mice which are LPS low responders. Seaweed extracts also enhanced Ig production by B cells and tumor necrosis factor (TNF) production by macrophages. Furthermore, seaweed extracts stimulated human lymphocytes to proliferate. All these B cell stimulating activities of seaweed extracts associated with glycoproteins whose molecular weights resided in 100 kD. These results suggest that seaweed extracts have stimulating activity on B cells and macrophages and this ability could be clinically for the modulation of immune responses.

Enhancing effect of polysaccharides from an edible brown alga, Hijikia fusiforme (Hijiki), on release of tumor necrosis factor-alpha from macrophages of endotoxin-nonresponder C3H/HeJ mice.

An enhancing activity for the release of tumor necrosis factor-alpha from macrophages of C3H/HeJ mice was detected in the hot water-soluble extract of an edible brown alga, Hijikia fusiforme (Hijiki in Japanese). This activity was divided into the polysaccharide and nonpolysaccharide fractions, with the former showing much higher activity than the latter. The active components in the polysaccharide fraction were further purified by ion-exchange column chromatography and gel permeation system of high-performance liquid chromatography; they were identified as polysaccharides with apparent molecular mass of about 2,000 and 70 kDa and were designated Hijiki-derived polysaccharides I and II (HPS-I and HPS-II), respectively. They also enhanced macrophage-dependent suppression against the growth of EL-4 tumor cells in an in vitro culture experiment, with HPS-I exhibiting much higher immunologic activity than HPS-II. Furthermore, other comparative experiments confirmed that the immunoenhancing activities of polysaccharides from H. fusiforme are associated with the functions of polysaccharides themselves, but not with the artificial activity induced by contaminated endotoxins. Some biochemical properties of immunoenhancing polysaccharides were partially characterized, and the significance of this finding is discussed from the viewpoint of the protective role of edible seaweeds against carcinogenesis.

Potent suppressive activity of nonpolyphenolic fraction of green tea (Camellia sinensis) against genotoxin-induced umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002), tumor promotor-dependent ornithine decarboxylase induction of BALB/c 3T3 fibroblast cells, and chemically induced mouse skin tumorigenesis.

Many experimental studies for anticarcinogenic activity of green tea (Camellia sinensis) and tea-derived polyphenols have been carried out. However, the anticarcinogenic activity of the nonpolyphenolic fraction of green tea has been poorly elucidated. To study this problem, the effect of the nonpolyphenolic fraction of green tea leaves was analyzed using in vitro and in vivo experiments associated with tumor initiation and promotion as follows: 1) The nonpolyphenolic fraction caused a strong suppressive effect on umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002) induced by genotoxic substances such as 2-amino-6-methyldipirido[1,2-a:3',2'-d]imidazole (Glu-P-1) and 2-aminoanthracene (2-AA) in the presence of a hepatic metabolizing enzyme mixture. 2) The same fraction showed a dose-dependent inhibition of ornithine decarboxylase (ODC) in BALB/c 3T3 fibroblasts induced by a tumor promotor, 12-O-tetradecanoylphorbol-13-acetate (TPA). 3) The same fraction also exhibited a significant suppression against mouse skin tumorigenesis induced by 7,12-dimethylbenz[a]anthracene (DMBA) (initiator) and TPA (promotor) through inhibition at both stages of tumor initiation and promotion. These results suggest that the nonpolyphenolic fraction of green tea has a potent suppressing activity against carcinogenesis associated with tumor initiation and promotion.

Potent suppressing activity of the non-polyphenolic fraction of green tea (Camellia sinensis) against genotoxin-induced umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002)--association with pheophytins a and b.

Antigenotoxic and antimutagenic activities of green tea extract and tea-derived polyphenols have been studied using in vitro and in vivo experiments. However, antigenotoxic substances in the non-polyphenolic fraction of green tea have been poorly elucidated. In the present study, the effect of the non-polyphenolic fraction of green tea on genotoxin-induced umu C gene expression was analyzed using a tester bacteria, and potent antigenotoxic substances in the non-polyphenolic fraction were identified. The non-polyphenolic fraction of green tea showed strong suppressive activities against umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002) induced by 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indol (Trp-P-1) or mitomycin C (MMC) in the presence or absence of S9 metabolizing enzyme mixture. The non-polyphenolic fraction of green tea exhibited major two-color bands in a silica gel TLC and they were identified as chlorophyll-related compounds, pheophytins a and b, judged by their specific colors, Rf values in silica gel TLC and absorption spectra. These pigments showed significant suppressive activities against umu C gene expression in tester bacteria induced by Trp-P- and MMC in a dose-dependent manner. These results suggest that the non-polyphenolic fraction of green tea contains pheophytins a and b as potent antigenotoxic substances.

Establishment and characterization of a canine T-lymphoblastoid cell line derived from malignant lymphoma.

A canine lymphoma cell line (CL-1) was established in culture from tumor cells found in the pleural fluid of a 7-year old female Japanese terrier with thymic form lymphoma. The CL-1 cells were positive for CD45 and MHC class II and negative for CD4, CD5, CD8, Thy-1 and B-cell specific antigen and surface immunoglobulin. The CL-1 cells had a rearranged T-cell receptor beta-chain gene and a germ-line form immunoglobulin gene, indicating that the CL-1 cells represented a monoclonally expanded population of canine alpha beta T-cell lineage.

Possible immunomodulating activities of carotenoids in in vitro cell culture experiments.

Immunomodulating activities of beta-carotene and carotene-associated carotenoids such as canthaxanthin (beta, beta-carotene-4,4 dione) and astaxanthin (3,3'-dihydroxyl beta, beta-carotene 4,4-dione) were analyzed by in vitro cell culture experiments. (i) beta-Carotene, canthaxanthin and astaxanthin caused significant stimulatory effects on the cell proliferative response of spleen cells and thymocytes from BALB/c mice at the concentrations of 2 x 10(-8) to 10(-7) M, although they showed the activities different from each other. (ii) Astaxanthin exhibited the highest activity on the polyclonal antibody (immunoglobulin M and G) production of murine spleen cells at the concentrations of 2 x 10(-8) to 10(-7) M but beta-carotene did not cause a significant effect at a low concentration (2 x 10(-8) M) although stimulated at a high concentration (2 x 10(-7) M). Canthaxanthin expressed moderate activities at the same concentrations. (iii) All tested carotenoids significantly enhanced the release of interleukin-1 alpha and tumor necrosis factor-alpha from murine peritoneal adherent cells at the concentrations of 2 x 10(-8) to 10(-7) M and the ranks of cytokine-inducing activities were astaxanthin > canthaxanthin > beta-carotene. These results indicate that carotenoids such as beta-carotene, canthaxanthin and astaxanthin have possible immunomodulating activities to enhance the proliferation and functions of murine immunocompetent cells.