Picosecond rotation of a ring-shaped optical lattice by using a chirped vortex-pulse pair

A novel method of ultrafast rotation of a ring-shaped optical lattice in the picosecond time region was proposed and demonstrated. Our ring-lattice generator was assembled by a pair of linearly chirped pulses with a time delay, a high-order birefringent retarder, and an axially symmetric polarization element. Using a mode-locked Ti:sapphire laser oscillator as a light source, stable two-, four-, and six-petaled ring-lattice rotations were demonstrated with the rotation periods of 1.6, 3.2, and 4.8 ps, respectively. Our method has the potential to open up a new technique to resonantly excite propagating quasi-particles together with their coherent enhancement.

Intracellular signal transduction evoked by low-density lipoprotein in vascular smooth muscle cells

Low-density lipoprotein (LDL) is a well-known causal factor in the development of arteriosclerosis. In the present study, we evaluated LDL-evoked cellular signal transduction in cultured rat vascular smooth muscle cells (VSMC). The addition of LDL at concentrations of more than 50 ng/ml, and apolipoprotein B (Apo-B) at more than 5 ng/ml, induced rapid but transient increases in the inositol 1,4,5-trisphosphate (InsP3) level, and caused rapid phasic and subsequent tonic increases in cytosolic free Ca2+ concentration [( Ca2+]i) in a dose-dependent manner in VSMC. LDL and Apo-B also caused transient acidification followed by Na(+)-dependent and amiloride-sensitive alkalization of the cells due to stimulation of a Na+/H+ exchanger. The enhancement of thymidine incorporation induced by the addition of LDL correlated well with the degree of increment of [Ca2+]i increases by the lipoprotein. These results suggest that an increase in [Ca2+]i mediated by InsP3 and intracellular alkalization may function as an important signal for enhanced DNA synthesis induced by LDL in VSMC.

Formation of a Transfer Product from Stevioside by the Cultures of Actinomycete

An Actinomycete, strain K-128, which was isolated from soil, formed a transfer product when the strain was cultured in a medium containing both stevioside and curdlan. The transfer product in culture broth was separated by DIAION HP-20 column and TOYOPEARL HW-40F column chromatographies. From structural studies, the transfer product was identified as C13-O-beta-6(2)-beta-glucosylsophorosyl-C19-O-beta-glucopyranosyl steviol. This product was the first to be obtained by a culture of an Actinomycete.

Expression of protein gene product 9.5 and Sal-like protein 4 in canine seminomas

The aim of the present study was to characterize canine classical seminoma (SE) and spermatocytic seminoma (SS) by immunohistochemical expression of gonocytic and spermatogonial cellular markers (c-Kit, placental alkaline phosphatase [PLAP], protein gene product 9.5 [PGP9.5] and Sal-like protein 4 [Sall4]) and histochemically by the periodic acid-Schiff (PAS) reaction. Twenty-five cases of SE and 23 cases of SS were investigated. Two cases of dysgerminoma were also examined. c-Kit was expressed on the cell membrane of 13 of 25 cases of SE (52%) and four of 23 cases of SS (16%). This marker was not expressed in dysgerminoma. PLAP immunoreactivity was observed in the cytoplasm of neoplastic cells of six of 25 cases of SE (24%). PLAP was not expressed in cases of SS and dysgerminoma. All samples of SE, SS and dysgerminoma showed cytoplasmic expression of PGP9.5 and nuclear immunoreactivity for Sall4. There was fine granular cytoplasmic PAS staining in neoplastic cells in five of 25 cases of SE (20%), while all samples of SS and dysgerminoma cases were PAS negative. These findings suggest that it is not possible to differentiate canine SE and SS using these markers. This may be because canine SS may be derived from spermatogonia that can differentiate to spermatocytes and also because cases of canine SE might consist of neoplastic cells that have lost their gonocytic nature. This study was the first to show positive immunoreactivity for Sall4 in canine seminomas and dysgerminomas and expression of PGP9.5 in canine dysgerminomas.

Modifying effects of liver tumor promotion in rats subjected to co-administration of indole-3-carbinol and phenobarbital

Indole-3-carbinol (I3C) and phenobarbital (PB) are cytochrome P450 (CYP) 1A and CYP2B inducers, respectively, and have liver tumor-promoting effects in rats. In this study, we investigated the modifying effects on tumor promotion by I3C and PB co-administration. Six-week-old male F344 rats received a single intraperitoneal injection of N-diethylnitrosamine for initiation treatment. Two weeks after the initiation, rats were given no tumor-promoting agents (DEN alone), I3C (2,500 or 5,000 ppm in diet), PB (60 or 120 ppm in drinking water), or 2,500 ppm I3C + 60 ppm PB for 6 weeks. One week after the I3C/PB treatments, all animals underwent a two-thirds partial hepatectomy. The number and area of liver cell foci positive for glutathione S-transferase placental form (GST-P(+) foci) were not significantly fluctuated in the PB+I3C group in the isoadditive statistical model. On the contrary, the mRNA levels of Cyp2b1/2 and Nqo1 were suppressed and enhanced, respectively, in the PB+I3C group in the isoadditive model, but there was no enhancement in the microsomal reactive oxygen species (ROS) production, thiobarbituric acid-reactive substance levels, and Ki-67(+) cell ratio in this group. The results suggest that the co-administration of I3C and PB causes no modifying effects in liver tumor promotion in rats.

Methacarn as a whole brain fixative for gene and protein expression analyses of specific brain regions in rats

For molecular analysis in anatomically-specific brain regions for rodent studies, it is necessary to establish a fast and accurate procedure for tissue sampling to achieve high integrity and expression fidelity of extracted molecules. The present study was performed to examine suitability of whole brain fixation with methacarn and subsequent tissue sampling using punch-biopsy devices for gene expression analysis in rats. After fixation, each specific region, i.e., hippocampal dentate gyrus, corpus callosum, cingulate cortex or cerebellar vermis was collected, and the integrity and variability of expression data of extracted total RNAs and polypeptides were examined. Methacarn fixation, acetone fixation, and unfixed tissues were compared. Methacarn fixation resulted in high integrity of total RNAs sufficient for conducting global expression analysis and superior in terms of uniformity in the integrity among brain regions to that of acetone fixation. Extracted polypeptide after methacarn fixation revealed similar integrity to that without fixation or with acetone fixation. Methacarn fixation resulted in lower mRNA expression variability between samples than acetone fixation in microarray analysis. The fidelity of polypeptide expression was mostly equivalent between methacarn and acetone fixation in 2-dimensional differential in-gel electrophoresis, although the expression levels of a small number of polypeptides from acetone-fixed tissues were affected. These results suggest that whole brain fixation with methacarn retains advantages for global analyses of mRNAs and polypeptides in rodent studies.

Liver tumor promoting effect of orphenadrine in rats and its possible mechanism of action including CAR activation and oxidative stress

Orphenadrine (ORPH), an anticholinergic agent, is a cytochrome P450 (CYP) 2B inducer. CYP2B inducers are known to have liver tumor-promoting effects in rats. In this study, we performed a rat two-stage liver carcinogenesis bioassay to examine the tumor-promoting effect of ORPH and to clarify its possible mechanism of action. Male rats were given a single intraperitoneal injection of N-diethylnitrosamine (DEN) as an initiation treatment. Two weeks after DEN administration, rats were fed a diet containing ORPH (0, 750, or 1,500 ppm) for 6 weeks. One week after the ORPH-administration rats were subjected to two-thirds partial hepatectomy for the acceleration of hepatocellular proliferation. The number and area of glutathione S-transferase placental form-positive foci significantly increased in the DEN-ORPH groups. Real-time RT-PCR revealed increased mRNA expression levels of Cyp2b1/2, Mrp2 and Cyclin D1 in the DEN-ORPH groups and of Gpx2 and Gstm3 in the DEN-High ORPH group. Microsomal reactive oxygen species (ROS) production and oxidative stress markers such as thiobarbituric acid-reactive substances and 8-hydroxydeoxyguanosine were increased in the DEN-High ORPH group. Immunohistochemically, constitutively active/androstane receptor (CAR) were clearly localized in the nuclei of hepatocytes in the DEN-ORPH groups. These results suggest that ORPH causes nuclear translocation of CAR resulting in the induction of the liver tumor-promoting activity. Furthermore, oxidative stress resulting from ROS production is also involved in the liver tumor-promoting activity of ORPH.

Suppressive effect of liver tumor-promoting activities in rats subjected to combined administration of phenobarbital and piperonyl butoxide

Phenobarbital (PB) is a cytochrome P450 (CYP) 2B inducer, and piperonyl butoxide (PBO) is a CYP1A/2B inducer. These inducers have liver tumor-promoting effects in rats. In this study, we performed a rat two-stage liver carcinogenesis bioassay to examine the tumor-promoting effect of PB and PBO co-administration. Male rats received an intraperitoneal injection of N-diethylnitrosamine (DEN) for initiation. Two weeks after DEN administration, rats were given PB (60 or 120 ppm in drinking water), PBO (1,250 or 2,500 ppm in diet) or 60 ppm PB+1,250 ppm PBO for 6 weeks. One week after the PB/PBO treatment, all rats were subjected to a two-thirds partial hepatectomy. To evaluate the effect of the combined administration, we used two statistical additive models. In the isoadditive model, the average values of the area of GST-P positive foci in the PB+PBO group were significantly lower than those in the High PB or High PBO groups. In the heteroadditive model, the net values of Cyp1a1 mRNA level and microsomal reactive oxygen species (ROS) production in the PB+PBO group were significantly lower than the sum of those in the Low PB or Low PBO groups. On the contrary, there was no interactive effect in the PCNA-positive hepatocyte ratio, mRNA levels of Cyp2b1/2, Gstm3, Gpx2 and Nqo1, and the level of thiobarbituric acid-reactive substances in the PB+PBO group. These results suggest that PB and PBO co-administration causes suppressive effects in liver tumor-promoting activity in rats resulting from inhibited microsomal ROS production because of suppression of CYP1A induction.

Immunohistochemical cellular distribution of proteins related to M phase regulation in early proliferative lesions induced by tumor promotion in rat two-stage carcinogenesis models

We have previously reported that 28-day treatment with hepatocarcinogens increases liver cells expressing p21(Cip1), a G1/S checkpoint protein, and M phase proteins, i.e., nuclear Cdc2, Aurora B, phosphorylated-Histone H3 (p-Histone H3) and heterochromatin protein 1α (HP1α), in rats. To examine the roles of these markers in the early stages of carcinogenesis, we investigated their cellular distribution in several carcinogenic target organs using rat two-stage carcinogenesis models. Promoting agents targeting the liver (piperonyl butoxide and methapyrilene hydrochloride), thyroid (sulfadimethoxine), urinary bladder (phenylethyl isothiocyanate), and forestomach and glandular stomach (catechol) were administered to rats after initiation treatment for the liver with N-diethylnitrosamine, thyroid with N-bis(2-hydroxypropyl)nitrosamine, urinary bladder with N-butyl-N-(4-hydroxybutyl)nitrosamine, and forestomach and glandular stomach with N-methyl-N'-nitro-N-nitrosoguanidine. Numbers of cells positive for nuclear Cdc2, Aurora B, p-Histone H3 and HP1α increased within preneoplastic lesions as determined by glutathione S-transferase placental form in the liver or phosphorylated p44/42 mitogen-activated protein kinase in the thyroid, and hyperplastic lesions having no known preneoplastic markers in the urinary bladder, forestomach and glandular stomach. Immunoreactive cells for p21(Cip1) were decreased within thyroid preneoplastic lesions; however, they were increased within liver preneoplastic lesions and hyperplastic lesions in other organs. These results suggest that M phase disruption commonly occur during the formation of preneoplastic lesions and hyperplastic lesions. Differences in the expression patterns of p21(Cip1) between thyroid preneoplastic and proliferative lesions in other organs may reflect differences in cell cycle regulation involving G1/S checkpoint function between proliferative lesions in each organ.

Increased cellular distribution of vimentin and ret in the cingulum of rat offspring after developmental exposure to decabromodiphenyl ether or 1,2,5,6,9,10-hexabromocyclododecane

Abstract: To determine effects of developmental exposure to brominated flame retardants (BFRs), weak thyroid hormone disruptors, on white matter development, white matter-specific global gene expression analysis was performed using microdissection techniques and microarrays in male rats exposed maternally to decabromodiphenyl ether (DBDE), one of the representative BFRs, at 10, 100 or 1000 ppm. Based on previous gene expression profiles of developmental hypothyroidism and DBDE-exposed cases, vimentin⁺ immature astrocytes and ret proto-oncogene (Ret)⁺ oligodendrocytes were immunohistochemically examined after developmental exposure to representative BFRs, i.e., DBDE, 1,2,5,6,9,10-hexabromocyclododecane (HBCD; 100, 1000 or 10,000 ppm) and tetrabromobisphenol A (TBBPA; 100, 1000 or 10,000 ppm). Vimentin⁺ and Ret⁺ cell populations increased at ≥ 100 ppm and ≥ 10 ppm DBDE, respectively. Vimentin⁺ and Ret⁺ cells increased at ≥ 1000 ppm HBCD, with no effect of TBBPA. The highest dose of DBDE and HBCD revealed subtle fluctuations in serum thyroid-related hormone concentrations. Thus, DBDE and HBCD may exert direct effects on glial cell development at ≥ middle doses. At high doses, hypothyroidism may additionally be an inducing mechanism, although its contribution is rather minor.

Inhibitory effect of α-lipoic acid on thioacetamide-induced tumor promotion through suppression of inflammatory cell responses in a two-stage hepatocarcinogenesis model in rats

To investigate the protective effect of α-lipoic acid (a-LA) on the hepatocarcinogenic process promoted by thioacetamide (TAA), we used a two-stage liver carcinogenesis model in N-diethylnitrosamine (DEN)-initiated and TAA-promoted rats. We examined the modifying effect of co-administered a-LA on the liver tissue environment surrounding preneoplastic hepatocellular lesions, with particular focus on hepatic macrophages and the mechanism behind the decrease in apoptosis of cells surrounding preneoplastic hepatocellular lesions during the early stages of hepatocellular tumor promotion. TAA increased the number and area of glutathione S-transferase placental form (GST-P)(+) liver cell foci and the numbers of proliferating and apoptotic cells in the liver. Co-administration with a-LA suppressed these effects. TAA also increased the numbers of ED2(+), cyclooxygenase-2(+), and heme oxygenase-1(+) hepatic macrophages as well as the number of CD3(+) lymphocytes. These effects were also suppressed by a-LA. Transcript levels of some inflammation-related genes were upregulated by TAA and downregulated by a-LA in real-time RT-PCR analysis. Outside the GST-P(+) foci, a-LA reduced the numbers of apoptotic cells, active caspase-8(+) cells and death receptor (DR)-5(+) cells. These results suggest that hepatic macrophages producing proinflammatory factors may be activated in TAA-induced tumor promotion. a-LA may suppress tumor-promoting activity by suppressing the activation of these macrophages and the subsequent inflammatory responses. Furthermore, a-LA may suppress tumor-promoting activity by suppressing the DR5-mediated extrinsic pathway of apoptosis and the subsequent regeneration of liver cells outside GST-P(+) foci.

Enhanced liver tumor promotion activity in rats subjected to combined administration of phenobarbital and orphenadrine

Phenobarbital (PB) and orphenadrine (ORPH) are cytochrome P450 (CYP) 2B inducers and have liver tumor-promoting effects in rats. In this study, we performed a rat two-stage liver carcinogenesis bioassay to examine the tumor-promoting effect of PB and ORPH co-administration. Twelve male rats per group were given an intraperitoneal injection of N-diethylnitrosamine (DEN) for initiation. Two-week after DEN administration, rats were given PB (60 or 120 ppm in drinking water), ORPH (750 or 1,500 ppm in diet) or 60 ppm PB+750 ppm ORPH for 6-week. One-week after the PB/ORPH treatment, all rats were subjected to two-thirds partial hepatectomy. To evaluate the effect of the combined administration, we used two statistical models: a heteroadditive model and an isoadditive model. In the heteroadditive model, the net values of the number and area of glutathione S-transferase placental form (GST-P) positive foci, Cyp2b1/2, Gstm3 and Gpx2 mRNA levels, microsomal reactive oxygen species (ROS) production and thiobarbituric acid-reactive substances level in the PB+ORPH group were significantly higher than the sum of the net values of those in the Low PB and Low ORPH groups. In the isoadditive model, the average values of the area of GST-P positive foci and PCNA positive hepatocyte ratio and Gstm3 mRNA level in the PB+ORPH group were significantly higher than the average values of those in the High PB and High ORPH groups. These results suggest that PB and ORPH co-administration causes synergistic effects in liver tumor-promoting activity in rats resulting from oxidative stress due to enhanced microsomal ROS production.

Preferential expression of cancer/testis genes in cancer stem-like cells: proposal of a novel sub-category, cancer/testis/stem gene

Cancer/testis (CT) antigens encoded by CT genes are immunogenic antigens, and the expression of CT gene is strictly restricted to only the testis among mature organs. Therefore, CT antigens are promising candidates for cancer immunotherapy. In a previous study, we identified a novel CT antigen, DNAJB8. DNAJB8 was found to be preferentially expressed in cancer stem-like cells (CSCs)/cancer-initiating cells (CICs), and it is thus a novel CSC antigen. In this study, we hypothesized that CT genes are preferentially expressed in CSCs/CICs rather than in non-CSCs/-CICs and we examined the expression of CT genes in CSCs/CICs. The expression of 74 CT genes was evaluated in side population (SP) cells (=CSC) and main population (MP) cells (=non-CSC) derived from LHK2 lung adenocarcinoma cells, SW480 colon adenocarcinoma cells and MCF7 breast adenocarcinoma cells by RT-PCR and real-time PCR. Eighteen genes (MAGEA2, MAGEA3, MAGEA4, MAGEA6, MAGEA12, MAGEB2, GAGE1, GAGE8, SPANXA1, SPANXB1, SPANXC, XAGE2, SPA17, BORIS, PLU-1, SGY-1, TEX15 and CT45A1) showed higher expression levels in SP cells than in MP cells, whereas 10 genes (BAGE1, BAGE2, BAGE4, BAGE5, XAGE1, LIP1, D40, HCA661, TDRD1 and TPTE) showed similar expression levels in SP cells and MP cells. Thus, considerable numbers of CT genes showed preferential expression in CSCs/CICs. We therefore propose a novel sub-category of CT genes in this report: cancer/testis/stem (CTS) genes.

Immunohistochemical characterization of neuroendocrine differentiation of canine anal sac glandular tumours

Histological features and expression of neuroendocrine markers were examined in 69 samples of canine anal sac glandular carcinomas (ASGCs). The tumours were classified into solid, rosette and tubular types and mixtures of these types. Tumour-associated death in dogs with solid tumours and mixed tumours with solid components was higher than in dogs with rosette and tubular type tumours. Chromogranin A immunoreactivity was observed in 28 of 69 samples (40.6%) irrespective of histological type and was localized to the marginal areas of the tumour nest and the basal areas of the tubular and rosette structures. Neuron-specific enolase immunoreactivity in neoplastic epithelial cells was observed in 32 cases (46.4%) and was less frequently observed in the tubular type (14.3%). Synaptophysin expression was present in 15.9% of cases and was least frequent in the tubular type. Twenty-one of the 69 samples expressed more than two neuroendocrine markers and were classified as carcinomas with neuroendocrine differentiation. There was no relationship between neuroendocrine differentiation and clinical outcome. These results suggest that some ASGCs have neuroendocrine differentiation regardless of histological pattern, but clinical outcome is more related to the histological pattern than to neuroendocrine differentiation.

Tumour endothelial marker-1 is expressed in canine Haemangiopericytomas

The aim of this study was to characterize immunohistochemically 18 cases of canine haemangiopericytoma (CHP) using two new candidate markers for pericytes, tumour endothelial marker (TEM)-1 and new glue (NG)-2, as well as the conventional mesenchymal cellular markers, vimentin, α-smooth muscle actin (α-SMA), desmin and von Willebrand factor (vWF). Because pericytes may have the same origin as endothelial or smooth muscle cells or the same differentiation potential as myofibroblasts, 17 cases of leiomyosarcoma (LMS), 20 cases of haemangiosarcoma (HS) and three cases of myofibroblastic sarcoma (MFS) were also examined. Expression of TEM-1 by >10% of the neoplastic population was observed in 94.4% (17/18) of haemangiopericytomas, 23.5% (4/17) of LMSs, 30.0% (6/20) of HSs and 66.7% (2/3) of MFSs. NG-2 expression by >10% of the neoplastic population was observed in 16.7% (3/18) of haemangiopericytomas, 52.9% (9/17) of LMSs, 0% (0/20) of HSs and 33.3% (1/3) of MFSs. Vimentin was expressed by all of tumours. In haemangiopericytoma, the incidence of positive immunoreactivity in >10% of the neoplastic population was 5.6% (1/18) for both α-SMA and desmin and 0% (0/18) for vWF. Considering the phenotypic features of cells expressing TEM-1, CHPs are thought to originate from immature vascular mural cells sharing their phenotype with myofibroblasts. NG-2 expression may be a phenotype of smooth muscle cells rather than pericytes in dogs.

Effect of enzymatically modified isoquercitrin on preneoplastic liver cell lesions induced by thioacetamide promotion in a two-stage hepatocarcinogenesis model using rats

To investigate the protective effect of enzymatically modified isoquercitrin (EMIQ) on the hepatocarcinogenic process, we used a two-stage hepatocarcinogenesis model in N-diethylnitrosamine-initiated and thioacetamide (TAA)-promoted rats. We examined the modifying effect of co-administration with EMIQ on the liver tissue environment including hepatic macrophages and lymphocytes and on the induction mechanism of preneoplastic cell apoptosis during early stages of hepatocellular tumor promotion. TAA increased the number and area of glutathione S-transferase placental form (GST-P)(+) liver cell foci and the numbers of proliferating and apoptotic cells in randomly selected areas in liver sections. Co-administration with EMIQ suppressed these effects. TAA also increased the numbers of ED2(+), cyclooxygenase-2(+), and heme oxygenase-1(+) liver cells, as well as the number of CD3(+) lymphocytes. These effects were also suppressed by EMIQ. EMIQ increased liver levels of thiobarbituric acid-reactive substance and 8-hydroxydeoxyguanosine, and TUNEL(+) apoptotic cells, death receptor 5 (DR5)(+) cells and 4-hydroxy-2-nonenal(+) cells within GST-P(+) foci. Outside the GST-P(+) foci, EMIQ decreased the numbers of apoptotic cells and DR5(+) cells. These results suggest that TAA-induced tumor promotion involves activation of hepatic macrophages producing proinflammatory factors. EMIQ may suppress the TAA-induced tumor-promoting activity by an anti-inflammatory mechanism mediated by suppressing the activation of these macrophages. Furthermore, EMIQ may suppress tumor-promoting activity differentially between the inside and outside of GST-P(+) foci. Within GST-P(+) foci, EMIQ facilitates the apoptosis of preneoplastic cells through the upregulation of DR5. Outside the GST-P(+) foci, EMIQ suppresses apoptosis and the subsequent regeneration of non-transformed liver cells.

Involvement of PTEN/Akt signaling and oxidative stress on indole-3-carbinol (I3C)-induced hepatocarcinogenesis in rats

We previously reported that indole-3-carbinol (I3C) had hepatocellular tumor-promoting activity in a short-term (8 weeks) two-stage liver carcinogenesis model in rats. It was suggested that this effect was related to the production of reactive oxygen species (ROS) caused by cytochrome P450 1A (CYP1A) induction. In the present study, 0.5% I3C was administered to DEN-initiated rats for 26 weeks to examine the effect of prolonged administration of I3C and to clarify the possible mechanisms of I3C-induced hepatocarcinogenesis. The number and area of GST-P positive foci, ROS production, TBARS level, 8-OHdG content and mRNA levels of Ahr and Nrf2 gene batteries significantly increased in the DEN-I3C group compared with the DEN-alone group. Furthermore, some GST-P positive preneoplastic foci progressed to hepatocellular adenomas with the prolongation of I3C administration. Lack of PTEN and phospho-Smad2/3 expression and translocations of PDPK1 and phospho-Akt substrates to underneath the cell membrane were observed in the majority of hepatocellular adenomas. In addition, the number of Ki-67 positive cells increased in adenomas compared with the preneoplastic foci. These results suggest that the administration of I3C for 26 weeks in DEN-initiated rats induces tumor progression from hepatocellular altered foci to hepatocellular adenomas by ROS-mediated Akt activation that inhibits the TGF-β/Smad signaling and results in the increased cell proliferation.

Liver tumor promoting effect of omeprazole in rats and its possible mechanism of action

Omeprazole (OPZ), a proton pump inhibitor, is a cytochrome P450 (CYP) 1A1/2 inducer. Some CYP1A inducers are known to have liver tumor promoting effects in rats and the ability to enhance oxidative stress. In this study, we performed a two-stage liver carcinogenesis bioassay in rats to examine the tumor promoting effect of OPZ (Experiment 1) and to clarify a possible mechanism of action (Experiment 2). In Experiment 1, male F344 rats were subjected to a two-third partial hepatectomy, and treated with 0, 138 or 276 mg/kg OPZ by oral gavage once a day for six weeks after an intraperitoneal injection of N-diethylnitrosamine (DEN). Liver weights significantly increased in the DEN+OPZ groups, and the number and area of glutathione S-transferase placental form (GST-P) positive foci significantly increased in the DEN+276 mg/kg OPZ group. In Experiment 2, the same experiment as Experiment 1 was performed, but the dosage of OPZ was 0 or 276 mg/kg. The number and area of GST-P positive foci as well as liver weights significantly increased in the DEN+276 mg/kg OPZ group. The number of proliferative cell nuclear antigen (PCNA)-positive cells also significantly increased in the same group. Real-time RT-PCR showed that the expression of AhR battery genes including Cyp1a1, Cyp1a2, Ugt1a6 and Nqo1, and Nrf2 battery genes including Gpx2, Yc2, Akr7a3, Aldh1a1 Me1 and Ggt1 were significantly upregulated in this group. However, the production of microsomal reactive oxygen species (ROS) and formation of thiobarbituric acid-reactive substances (TBARS) decreased, and 8-hydroxydeoxyguanosine (8-OHdG) content remained unchanged in this group. These results indicate that OPZ, CYP1A inducer, is a liver tumor promoter in rats, but oxidative stress is not involved in the liver tumor promoting effect of OPZ.

Threshold dose of liver tumor promoting effect of β-naphthoflavone in rats

To determine the threshold dose of β-Naphthoflavone (BNF) that induces hepatocellular tumor promoting effects, reactive oxygen species (ROS) generation and thiobarbituric acid-reactive substance (TBARS) formation, and drug-metabolizing enzymes that protect against ROS generation, two-stage liver carcinogenesis model was used. Partial hepatectomized rats (n = 11 to 12) were fed diets containing 0, 0.03, 0.06, 0.125 or 0.25% BNF for 6 weeks after an intraperitoneal injection of N-diethylnitrosamine (DEN) to initiate hepatocarcinogenesis. Histopathologically, glutathione S-transferase placental form (GST-P)-positive foci significantly increased in rats given 0.25% BNF. No marked changes in ROS production and TBARS contents were observed between the BNF treated and DEN alone groups. Real-time RT-PCR showed that the expression of Cyp1a1, Cyp1a2, Cyp1b1 and Nqo1 significantly increased in the groups given 0.03% BNF or more, but Ugt1a6, Akr7a3 and Gstm1 significantly increased in the groups given 0.125% BNF or more. Gpx2 and Yc2 significantly increased in the groups given 0.06% BNF or more and 0.25% BNF, respectively. Inflammation-related genes such as Ccl2, Mmp12, Serpine1 and Cox-2 significantly increased in the 0.25% BNF group. In immunohistochemistry, the number of cyclooxygenase-2 (COX-2)-positive cells increased in rats given 0.25% BNF. These results suggest that 0.25% BNF is the threshold dose for liver tumor promotion, and the fact that inflammation-related genes and COX-2 protein increased in the 0.25% BNF group strongly suggests that inflammation is involved in the liver tumor promoting effect of BNF in rats.

Enhanced liver tumor promotion but not liver initiation activity in rats subjected to combined administration of omeprazole and β-naphthoflavone

Omeprazole (OPZ) and β-naphthoflavone (BNF) are cytochrome P450 (CYP)1A inducers and have liver tumor promoting effects. In this study, we investigated the co-promoting and co-initiating effects of OPZ and BNF in rats. In Experiment 1, male rats were subjected to partial hepatectomy (PH), and given oral doses of 138 or 276 mg/kg OPZ, 0.125% or 0.25% BNF or 138 mg/kg OPZ+0.125% BNF (n = 9~12) for 6 weeks after N-diethylnitrosamine (DEN) initiation. In Experiment 2, male rats were treated with oral doses of 138 or 276 mg/kg OPZ, 0.03% or 0.06% BNF or 138 mg/kg OPZ+0.03% BNF (n = 11~12) for 9 days starting 1 week before initiating treatment. As an initiating treatment, 2-Amino-3,4-dimethylimidazo[4,5-f]quinolone (MeIQx) was orally administered 12 hr after PH. The rats were fed a basal diet for 15 days, followed by a diet containing 0.015% 2-acetylaminofluorene for the next 10 days with a single oral dose of carbon tetrachloride. In Experiment 1, the number and area of glutathione S-transferase placental form-positive foci in the OPZ+BNF group were significantly higher than the average values of the High OPZ or the High BNF group. The expression of cyclooxygenase-2 (Cox-2) and COX-2 protein in the liver significantly increased in the OPZ+BNF group. In Experiment 2, liver initiation activity was not enhanced by the co-administration of OPZ+BNF. The results of our studies suggest that the co-administration of OPZ and BNF results in synergistic effects in the liver tumor promotion probably owing to increased COX-2 expression, but no modifying effect in the liver initiation activity of MeIQx in rats.

Alterations of the p53 tumor-suppressor gene and ki-ras oncogene in human pancreatic cancer-derived cell-lines with different metastatic potential

Alterations of the p53 and Ki-ras genes were examined in 12 human pancreatic cancer-derived cell lines with different metastatic potential. Point mutations of the Ki-ras gene at codon 12 were found in 10 out of 12 cell lines (83%), while abnormalities of the p53 gene were identified in 8 out of 12 cell lines (67%) which included point mutations (n=7) and one base deletion (n=1). The comparison between alterations of the p53 and Ki-ras genes showed that all the 12 cell lines revealed alterations of both genes or one of these genes regardless of the metastatic potential. Further, same alterations of the Ki-ras gene or p53 gene were noted among the cell lines with increased metastatic potential and their parental cell lines. These findings suggest that alterations of the p53 gene, like the Ki-ras gene is a frequent event in pancreatic cancer, and could contribute cooperatively in the oncogenic steps of pancreatic cancer. It is also suggested that the genetic changes of the p53 and Ki-ras genes are not substantially associated with the metastatic potential in pancreatic cancer.

Developmental exposure to manganese chloride induces sustained aberration of neurogenesis in the hippocampal dentate gyrus of mice

The effect of exogenously administered manganese (Mn) on developmental neurogenesis in the hippocampal dentate gyrus was examined in male mice after maternal exposure to MnCl(2) (0, 32, 160, or 800 ppm as Mn in diet) from gestational day 10 to day 21 after delivery on weaning. Immunohistochemistry was performed to monitor neurogenesis and interneuron subpopulations on postnatal days (PNDs) 21 and 77 (adult stage). Reelin-synthesizing γ-aminobutyric acid (GABA)ergic interneurons increased in the hilus with ≥ 160 ppm on weaning to sustain to PND 77 at 800 ppm. Apoptosis in the neuroblast-producing subgranular zone increased with 800 ppm and TUC4-expressing immature granule cells decreased with 800 ppm on weaning, whereas at the adult stage, immature granule cells increased. On PND 21, transcript levels increased with Reln and its receptor gene Lrp8 and decreased with Dpysl3 coding TUC4 in the dentate gyrus, confirming immunohistochemical results. Double immunohistochemistry revealed a sustained increase of reelin-expressing and NeuN-lacking or weakly positive immature interneurons and NeuN-expressing mature neurons in the hilus through to the adult stage as examined at 800 ppm. Brain Mn concentrations increased at both PNDs 21 and 77 in all MnCl(2)-exposed groups. These results suggest that Mn targets immature granule cells causing apoptosis and neuronal mismigration. Sustained increases in immature reelin-synthesizing GABAergic interneurons may represent continued aberration in neurogenesis and following migration to cause an excessive response for overproduction of immature granule cells through to the adult stage. Sustained high concentration of Mn in the brain may be responsible for these changes.

Antioxidant N-acetyl-L-cysteine (NAC) supplementation reduces reactive oxygen species (ROS)-mediated hepatocellular tumor promotion of indole-3-carbinol (I3C) in rats

Indole-3-carbinol (I3C) has a liver tumor promoting activity in rats, and is also known as a cytochrome p450 1A (CYP1A) inducer. The generation of reactive oxygen species (ROS) resulting from CYP1A induction due to I3C, is probably involved in the tumor promotion. To clarify whether ROS generation contributes to I3C's induction of hepatocellular altered foci, partially hepatectomized rats were fed a diet containing 0.5% of I3C for 8 weeks with or without 0.3% N-acetyl-L-cysteine (NAC), an antioxidant, in their drinking water after N-diethylnitrosamine (DEN) initiation. Immunohistochemical analysis showed that the glutathione-S-transferase placental form (GST-P) positive foci promoted by I3C were suppressed by the administration of NAC. The mRNAs of members of the phase II nuclear factor, erythroid derived 2, like 2 (Nrf2) gene batteries, whose promoter region is called as antioxidant response element (ARE), were down-regulated in the DEN-I3C-NAC group compared to the DEN-I3C group, but Cyp1a1 was not suppressed in the DEN-I3C-NAC group compared to the DEN-I3C group. There was no marked difference in production of microsomal ROS and genomic 8-hydroxy-2'-deoxygunosine (8-OHdG) as an oxidative DNA marker between the DEN-I3C-NAC and DEN-I3C groups, while mapkapk3 and Myc were decreased by the NAC treatment. These results indicate that oxidative stress plays an important role for I3C's tumor promotion, and NAC suppresses induction of hepatocellular altered foci with suppressed cytoplasmic oxidative stress.

Possible mechanism of superoxide formation through redox cycling of plumbagin in pig heart

The purpose of this study is to elucidate the possible mechanism of superoxide formation through redox cycling of plumbagin (PLG) in pig heart. Of four 1,4-naphthoquinones tested in this study, PLG was most efficiently reduced in the cytosolic fraction of pig heart. On the other hand, lawsone (LAS) was little reduced. Thus, whether or not PLG and LAS induce the formation of superoxide anion radical in pig heart cytosol was examined, by using the methods of cytochrome c reduction and chemiluminescence. PLG significantly induced the formation of superoxide anion radical, even though LAS had no ability to mediate superoxide formation. PLG was a significant inhibitor for the stereoselective reduction of 4-benzoylpyridine (4-BP) catalyzed by tetrameric carbonyl reductase (TCBR) in pig heart cytosol. Furthermore, PLG was confirmed to competitively inhibit the 4-BP reduction, and the optimal pH for the PLG reduction was around 6.0 similar to that for the 4-BP reduction. These results suggest that PLG mediates superoxide formation through its redox cycling involved in the two-electron reduction catalyzed by TCBR, and induces oxidative stress in pig heart.

Indole-3-carbinol enhances oxidative stress responses resulting in the induction of preneoplastic liver cell lesions in partially hepatectomized rats initiated with diethylnitrosamine

The liver tumor-promoting effects of indole-3-carbinol (I3C), a cytochrome P450 (CYP) 1A inducer found in cruciferous vegetables, were investigated using a medium-term hepatocarcinogenesis model in rats. Six-week-old male F344 rats received an intraperitoneal injection of N-diethylnitrosamine (DEN) and were fed a diet containing 0 (DEN-alone), 0.25, 0.50 or 1.0% of I3C for 8 weeks from 2 weeks after DEN-initiation. The number and area of liver cell foci positive for glutathione S-transferase placental form (GST-P) significantly increased in the livers of rats given 0.5% I3C or more, compared to those in the DEN-alone group. The number of GST-P positive foci also increased in the 0.25% I3C group. The number of liver cells positive for proliferating cell nuclear antigen (PCNA) significantly increased in all I3C groups compared to that in the DEN-alone group. Real-time RT-PCR analysis showed that I3C increased transcript levels of not only Cyp1a1 but also aryl hydrocarbon receptor (AhR) and/or nuclear factor (erythroid-derived 2)-like 2 (Nrf2) gene batteries, such as Cyp1a2, Cyp1b1, Ugt1a6, Nrf2, Nqo1, Gsta5, Gstm2, Ggt1and Gpx2. Reactive oxygen species (ROS) in the microsomal fraction significantly increased in all I3C-treated groups compared to the DEN-alone group, and thiobarbituric acid-reactive substances (TBARS) levels and 8-hydroxy-2'-deoxyguanosine (8-OHdG) content significantly increased in all of the I3C-treated groups and 1.0% I3C group, respectively. These results suggest that I3C is an AhR activator and enhances microsomal ROS production resulting in the upregulation of Nrf2 gene batteries, but the oxidative stress generated overcomes the antioxidant effect of Nrf2-related genes. Such 'a redox imbalance' subsequently induces liver tumor-promoting effects by enhancing cellular proliferation in rats.

A neuroendocrine carcinoma of undetermined origin in a dog

In this report, we describe a case of neuroendocrine carcinoma of undetermined origin in a dog. Necropsy revealed scattered small neoplastic nodules in the bilateral lungs and a small nodule in the parapancreatic lymph node. Histopathologically, both pulmonary and lymph nodal nodules showed a similar histologic pattern, with neoplastic cells being arranged in diffusely proliferating sheet-like cellular nests separated by variable amounts of fibrous septa, sometimes forming rosettes and duct-like structures. Scattered small necrotic foci and invasion to fibrous septa were typically observed. Neoplastic cells showed round to oval-shaped nuclei with prominent nucleoli and abundant eosinophilic cytoplasm that were positive for Grimelius' silver impregnation staining and immunostaining with cytokeratin, synaptophysin, vasoactive intestinal peptide and chromogranin A, indicative of the development of a neuroendocrine carcinoma. However, judging from the distribution of tumors lacking the portion suggestive of the primary site in any organ examined, as well as no further indication of differentiation potential of neoplastic cells, this tumor has so far been diagnosed as neuroendocrine carcinoma of undetermined origin.

Dynamics of a paired optical vortex generated by second-harmonic generation

We study the dynamics of a paired optical vortex (OV) generated by second-harmonic generation (SHG) using sub-picosecond pulses. By changing the position of a thin nonlinear crystal along the propagation direction, we observe a rotation of two vortices with changing separation distance. The dynamics is well explained by SHG with a beam walk-off, which introduces a contamination of zero-order Laguerre-Gaussian beam (LG(0)) together with topological charge doubling. The quantitative analysis indicates that the rotation angle of the OVs manifests the Gouy phase while the splitting provides the walk-off angle of the crystal. We also show that the subtraction of LG(0) is realized by the superposition of LG(0) with an anti-balanced phase in the pump.

A mixed apocrine gland tumor with metastases to the bone and bone marrow in a miniature poodle

A 10-year-old female miniature poodle had a mass in its carpal joint of the left forelimb. The tumor was divided into small multiple lobules by delicate connective tissues, and necroses were found in some of the central lobules. In some connective stromal areas, chondroid and osteoid tissues were formed. The tumor cells were similar to the structure of apocrine gland epithelial cells with apical blebs resembling apocrine secretion and eosinophilic secretary materials within the luminal space, and spindle cells were sometimes found in the basal area of the glandular structure. In some areas, tumor cells invaded in the blood vessels, bone and bone marrow. Immunohistochemically, the tumor cells forming tubulo-acinar to solid structures were intensely positive for cytokeratin and keratin K8/K18, and the spindle cells were positive for vimentin and alpha-smooth muscle actin. This case was diagnosed as a malignant mixed apocrine gland tumor with metastases to the bone and bone marrow.

Coherent transfer of orbital angular momentum to excitons by optical four-wave mixing

We demonstrate the coherent transfer of optical orbital angular momentum (OAM) to the center of mass momentum of excitons in semiconductor GaN using a four-wave mixing (FWM) process. When we apply the optical vortex (OV) as an excitation pulse, the diffracted FWM signal exhibits phase singularities that satisfy the OAM conservation law, which remain clear within the exciton dephasing time (approximately 1ps). We also demonstrate the arbitrary control of the topological charge in the output signal by changing the OAM of the input pulse. The results provide a way of controlling the optical OAM through carriers in solids. Moreover, the time evolution of the FWM with OAM leads to the study of the closed-loop carrier coherence in materials.

Extramammary Paget's disease: treatment, prognostic factors and outcome in 76 patients

BACKGROUND

Extramammary Paget's disease (EMPD) is a rare cutaneous carcinoma usually presenting as a genital erythematous lesion in the elderly. Although most EMPD tumours are in situ, invasive EMPD has a poor prognosis.

OBJECTIVE

To evaluate the clinical and pathological features of EMPD and determine prognostic factors for survival.

METHODS

The medical records of 76 patients with EMPD were retrospectively reviewed.

RESULTS

Of the 66 patients who underwent curative surgical excision, five (8%) developed local recurrence, but surgical margin (<or=2 cm or >2 cm) was not correlated with local recurrence. Thirteen of the 76 patients (17%) developed systemic metastases and 10 of these died of disease. On univariate analysis, the presence of nodules in the primary tumour, clinical lymph node swelling, elevated serum carcinoembryonic antigen (CEA) levels, tumour invasion level and lymph node metastasis were significant prognostic factors. On multivariate analysis, invasion level and elevated serum CEA were the only factors that were significantly associated with reduced survival.

CONCLUSIONS

Invasion level and lymph node metastasis are important prognostic factors in EMPD. In patients with in situ tumour, local tumour control is the major aim of treatment; however, wide surgical margins are not associated with a lower risk of local recurrence.