Nephrocalcinosis formation by soy isoflavones in male rats

Isoflavones (IFs), found in the form of both aglycones and glucosides in soybean foods, induce weak estrogenic activities. Although IFs have a number of health benefits, it was previously reported that IFs cause nephrocalcinosis (NC) in the kidney of male Fischer 344 (F344) rats. The present study aims to elucidate the safety of IFs by focusing on IF-induced NC formation in rats. Fermented soybean extract (FSE) containing 420 mg/g isoflavone aglycones was orally administered to male F344 and Sprague-Dawley (SD) rats for 28 days. FSE induced NC formation in the kidney of F344 rats, but not in SD rats. However, absorption of IFs did not differ between F344 and SD rats. NC formation and its severity of FSE were histologically compared with those of soybean extract (SE) containing 518 mg/g isoflavone glucosides in F344 rats. There were no differences in the number of NC formations and the extent of calcium deposit between FSE and SE groups. To examine the dose effect of FSE on NC formation, doses of 20, 140, or 1000 mg/kg FSE were administered to F344 rats for 90 days. NC formation was observed in the 140 and 1000 mg/kg groups. These results indicated that a high dose of oral administration of IFs induced NC formation depending on the strain of rat.     

Lack of hepatocarcinogenicity of 2,2’-[1,2-ethanediylbis(oxymethylene)]bis-oxirane, 3-hydroxy-2-naphthoic acid,and acetoacetanilide in a medium-term rat liver bioassay

The carcinogenicity of 2,2’-[1,2-ethanediylbis(oxymethylene)]bis-oxirane (ethylene glycol diglycidyl ether; EGDE), 3-hydroxy-2-naphthoic acid (HNA), and acetoacetanilide (AAA) was investigated using a medium-term rat liver bioassay for an occupational safety assessment. F344 male rats were administered a single intraperitoneal injection of diethylnitrosamine (200 mg/kg body weight (bw)/day) and then starting 2 weeks later, they received EGDE at 6, 20, and 60 mg/kg bw/day, HNA at 20, 60, and 200 mg/kg bw/day, or AAA at 60, 200, and 600 mg/kg bw/day by oral gavage for 6 weeks. The animals in the positive control group received phenobarbital sodium solution (PB, 25 mg/kg bw/day) by oral gavage and those in the negative control group received a vehicle (water/corn oil) during the administration period of test substances in this model. All animals were subjected to two-thirds partial hepatectomy at week 3 and euthanized at week 8. Neither the number nor the area of hepatocellular foci positive for glutathione S-transferase placental form (GST-P) increased in any of the EGDE, HNA, or AAA treated groups. However, the number and area of GST-P-positive foci significantly increased in the positive control group treated with PB. The results indicate that EGDE, HNA, and AAA lack hepatocarcinogenicity in rats.     

Effect of nitrogen deposition on CH4 uptake in forest soils in Hokkaido,Japan

Abstract

It has been well documented by short-term artificial experiments that the CH⁴ uptake is inhibited by N input, especially NH^{4 p+}-N input. To investigate the effect of the natural N input by throughfall and other factors on the CH⁴ uptake in forest soils, we measured the CH⁴ uptake rates for 6 months during the snow-free period of the year and N input by throughfall throughout the year at 10 sites in Hokkaido, Japan, from 1997 to 2002. Water filled pore space (WFPS) and pH values in the soils varied widely among the sites (38-93% and 3.9-6.2, respectively). The rates of NH^{4 p+}-N and NH^{3 p-}-N inputs ranged from 1.3 to 6.9 kg N ha^p-1 year^p-1 and from 0.8 to 2.9 kg N ha^p-1 year^p-1, respectively. The NH^{4 p+}-N input was generally higher than the NH^{3 p-}-N input. Total N input by throughfall amounted to 2.3-9.4 kg N ha^p-1 year^p-1. The highest CH⁴ uptake rate occurred within the period from July to September (41-215 μg CH⁴ m^p-2 h^p-1) each year at most sites. CH⁴ uptake rate was relatively low (~50 μg CH⁴ M-2 h^p-1) at northern sites, while a high CH⁴ uptake rate was observed throughout the year 100 (? CH⁴ m^p-2 h^p-1) at southern sites. The mean CH⁴ uptake rates were significantly different among the sites. Cumulative CH⁴ uptake ranged from 1.4 to 6.6 kg CH⁴ ha^p-1 [184 d]^p-1 with a mean values of 3.22 ± 1.36 kg CH⁴ ha^p-1 [184 d]^p-1. Cumulative CH⁴ uptake increased with increasing temperature and decreased with an increase in precipitation (Rain), NH^{4 p+}-N input (TF^NH4) WFPS, soil total C (TC), and total N (TN). There was a quadratic relationship between the CH⁴ uptake and NH^{3 p-}-N input (TF^NO3), soil pH, and C / N ratio in soil. A regression equation was obtained as follows to predict the CH⁴ uptake in forest soils: Cumulative CH⁴ uptake = 0.47 / Rain + 0.38 / TF^NH4 + 0.34 / TC - 0.30 / TF^N03 (R ^p2 = 0.74, p = 0.0001). This equation indicates that atmospheric N input into forest soils is one of the main factors that control cumulative CH⁴ uptake with precipitation, total carbon content in soil in Hokkaido, Japan.     

Hepatocellular carcinoma in a young dog

A 25-month-old Chihuahua dog with no clinical signs was evaluated for high serum liver enzymes. Ultrasonography and computed tomography revealed a mass in the left hepatic medial lobe. The histological diagnosis reached using resected tissues was hepatocellular carcinoma (HCC). To the authors’ knowledge, this is the youngest dog diagnosed with HCC.     

Corrosive-wear characteristics of diamond-coated cemented carbide tools

Continuous milling tests with diamond-coated and uncoated cemented carbide tools and polycrystalline diamond tools were carried out on air-dried and wet melapi (Shorea sp.) and western redcedar (Thuja plicata D. Don). These tools were examined for corrosive-wear characteristics of the tool-edge appearance, cutting-edge profile, edge recession, and cutting-power consumption. The tool surfaces were observed with a scanning electron microscope and were analyzed by energy-dispersive X-ray spectroscopy. Based on these examinations, the occurrence of corrosive wear while cutting wet woods was confirmed for the uncoated and polycrystalline diamond tools. In contrast, the coated tools did not exhibit corrosive wear, nor did delamitation or wear of the diamond film occur with any of the work materials. The diamond-coated tools showed high resistance not only to mechanical wear but also to corrosive wear.The results of this work were presented at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998     

Toll-like receptor 2 and 9 are expressed and functional in gut-associated lymphoid tissues of presuckling newborn swine

To clarify the crucial role of Toll-like receptor (TLR) 2 and TLR9 in immature gut-associated lymphoid tissues (GALT), we focused on the expression of TLR2 and TLR9 and the immune responses induced by their ligands in the GALT of presuckling newborn swine. Quantitative real-time PCR revealed that TLR2 and TLR9 mRNA were expressed at detectable levels in all tested tissues (heart, thymus, lung, spleen, liver, kidney, skeletal muscle, duodenum, jejunum, ileum, ileal Peyer patches (Pps), and mesenteric lymph nodes (MLN)). In particular, in immature intestinal tissues and GALT, TLR2 and TLR9 mRNA were expressed at higher levels in ileal Pps and MLN than in the duodenum, jejunum, and ileum. We confirmed that the TLR2 and TLR9 proteins were also highly expressed and that their ligands were preferentially recognized by TLR2- or TLR9-expressing cells in the MLN and ileal Pps. Zymosan, CpG2006, and lactic acid bacteria could promote mitogenesis and production of multiple cytokines by the MLN and ileal Pps. In addition, double immunostaining for cytokeratin 18 and either TLR2 or TLR9 revealed that both TLR2 and TLR9 are strongly expressed in the columnar membranous (M) cells. Interestingly, while the apical membrane of the columnar M cells strongly expressed TLR2 protein and preferentially recognized zymosan, both "TLR2 expression on the apical membrane" and "TLR2-mediated zymosan binding" were negligible in neighboring enterocytes. These results indicate that TLR2 and TLR9 allow MLN and ileal Pps to respond to a variety of bacterial components immediately after birth, thereby providing newborns with a host defense system.     

Cellular localization of IL-18 and IL-18 receptor in pig anterior pituitary gland

Pro-inflammatory cytokine interleukin 18 (IL-18) has been proposed to have a role in modulating immuno-endocrine functions. Our previous study showed that IL-18 and IL-18 receptor (IL-18R) colocalized in somatotrophs of the bovine anterior pituitary gland, and the possibility that IL-18 acts on somatotrophs as an autocrine factor. In the present study, we investigated the localization of IL-18 and IL-18R in the pig anterior pituitary gland. RT-PCR analysis showed the expression of IL-18 and IL-18R mRNAin the pig anterior pituitary gland. Immunohistochemistry of IL-18 and specific hormones revealed the presence of IL-18 in somatotrophs, mammotrophs, thyrotrophs and gonadotrophs. IL-18R was localized in somatotrophs and thyrotrophs. Furthermore, the somatotrophs immunoreactive for IL-18 did not contain IL-18R. Thus, IL-18R and IL-18 were not colocalized in an identical somatotroph. These findings suggest that the localization of IL-18 in pig somatotrophs is different from that in bovine somatotrophs, although IL-18 closely associates with somatotrophs in the anterior pituitary glands in both species.     

Alterations of lymphocyte subpopulations in healthy dogs with aging and in dogs with cancer

Changes in an individual's immune status are considered major contributing factors towards the morbidity of cancer and mortality of aging. To evaluate age-related changes in the immune status of dogs, the immunophenotypes (CD3, CD4, CD8 and CD21) of peripheral blood lymphocytes were measured in 160 healthy dogs aged from 1 to 17 years, and in 365 dogs with various tumors and at various stages. In healthy dogs, the absolute numbers of white blood cells, lymphocytes, and CD3(+), CD4(+) and CD21(+) lymphocytes decreased significantly with age. The relative percentages of lymphocytes and CD4(+) cells decreased significantly, while CD8(+) cells increased significantly with age. The CD4:CD8 ratio showed a significant age-related decrease. In contrast, dogs with tumors possessed significantly lower absolute numbers and relative percentages of all lymphocyte phenotypes, while the CD4:CD8 ratio was significantly higher than in age-matched controls. The relative percentages of CD3(+) and CD8(+) lymphocytes were significantly lower in dogs with distant metastases compared with dogs without metastases, and the CD4:CD8 ratio increased with advanced stage. These observations illustrate the significant changes in immune status with age and the presence of marked immunological defects in a large-scale study of dogs with advanced tumors.     

Chromosome doubling of Lychnis spp. by in vitro spindle toxin treatment of nodal segments

Lychnis (Caryophyllaceae) consists of about 30 species distributed throughout the temperate regions of the Northern Hemisphere, from East Asia to Europe. Many Lychnis spp. have high ornamental value and cultivated as pot or garden plants. In the present study, in vitro chromosome doubling of several Lychnis spp. was examined in order to widen their variability in horticultural traits. Initially effect of various spindle toxin treatments [100, 500 or 1000 mg l⁻¹ colchicine (COL), 10, 20 or 50 mg l⁻¹ oryzalin (ORY), or 1, 5, 10 mg l⁻¹ amiprophos-methyl (APM)] of nodal segments of a triploid genotype of L. senno (3x) was investigated on survival of nodal segments and chromosome doubling in nodal segment-derived plantlets. Significantly higher percentage (75.0%) of surviving segments after spindle toxin treatment was obtained in 10 mg l⁻¹ ORY treatment. Flow cytometry (FCM) analysis of leaf tissues showed that 9.4–13.8% of plantlets, which were derived from 10 to 20 mg l⁻¹ ORY, or 5 mg l⁻¹ APM treatments, were hexaploid (6x) or ploidy chimera (3x + 6x, 4x + 6x, 5x + 6x, 3x + 4x + 6x). The results obtained by FCM analysis were confirmed by chromosome observation in root tip cells. Thus 10 mg l⁻¹ ORY treatment of nodal segments is suitable for in vitro chromosome doubling of triploid L. senno. Efficient chromosome doubling was also achieved in diploid L. fulgens (2x) and L. sieboldii (2x) by treating nodal segments with 10 mg l⁻¹ ORY: 68.9–88.7% of nodal segments survived after ORY treatment, and 24.7–26.5% of plantlets derived from ORY-treated nodal segments were tetraploid (4x) or ploidy chimera (2x + 4x) in both species. These results indicate that the in vitro chromosome doubling method established for triploid L. senno may be applicable to a wide range of Lychnis spp. Tetraploid L. fulgens and L. sieboldii showed a compact plant form, and had thick stems and deep green leaves compared with the diploid mother plants. On the other hand, hexaploid L. senno showed very poor growth and died before flowering.