Uterine Carcinosarcoma in a 2-year-old Female Wistar Hannover GALAS Rat

Carcinosarcomas are rare tumors in humans as well as rats and most commonly occur in the uterus. Recently, we observed a case of incidental carcinosarcoma of the uterus in a female Wistar Hannover GALAS [BrlHan:WIST@ Jcl (GALAS)] rat at 2 years of age. Histopathologically, the tumor was characterized by an admixture of malignant epithelial and nonepithelial elements. The carcinomatous components represented a type of endometrial carcinoma, consisting of glandular and solid proliferation of large-sized tumor cells. Prominent mitoses and tumor cell invasion were observed. The sarcomatous components were characterized by multifocal proliferation of severe atypical cells with cartilage matrix and were diagnosed as chondrosarcoma. Transitions between carcinomatous and sarcomatous components were observed, and many tumor cells in the solid lesion showed immunohistochemical reactivity with both cytokeratin and vimentin. Based on these findings, this tumor was diagnosed as a uterine carcinosarcoma. This is the first report of uterine carcinosarcoma in Wistar Hannover GALAS [BrlHan:WIST@Jcl (GALAS)] rats.     

The use of tetracycline in anthelmintic baits to assess baiting rate and drug efficacy against Echinococcus multilocularis in foxes

Anthelmintic (praziquantel) baiting of wild red foxes against Echinococcus multilocularis infection was studied in a highly epizootic suburban area of Otaru, Hokkaido (the northern island of Japan) during the summer and autumn in the years 1999-2004. Acceptance of baits containing the biomarker tetracycline (TC) was evaluated. The prevalence of E. multilocularis infection in foxes before baiting (1999-2000) was 58% (88/153), whereas in the fourth year of bait distribution year (2004), it decreased to 11% (5/45). Analysis of TC marking in the teeth of foxes showed that 39% (77/195) of those captured after baiting were estimated to have consumed baits in the year of capture. Importantly, more juvenile (56%, 49/87) than adult foxes (26%, 28/108) were marked, indicating efficient baiting of juveniles, which tended to have a higher worm burden of E. multilocularis. Of 77 marked foxes, E. multilocularis and Alaria alata (monitored as the second indicator species of deworming) were not detected in 70 (90%) and 76 (99%) foxes, respectively. The results suggest effective deworming by bait consumption. However, it was also demonstrated that 9% of the marked foxes were infected or re-infected after bait consumption, suggesting high infection pressure and the importance of frequent baiting.     

Pluripotent cell derivation from male germline cells by suppression of Dmrt1 and Trp53

Diploid germ cells are thought to have pluripotency potential. We recently described a method to derive pluripotent stem cells (PSCs) from cultured spermatogonial stem cells (SSCs) by depleting Trp53 and Dmrt1, both of which are known suppressors of teratomas. In this study, we used this technique to analyze the effect of this protocol in deriving PSCs from the male germline at different developmental stages. We collected primordial germ cells (PGCs), gonocytes and spermatogonia, and the cells were transduced with lentiviruses expressing short hairpin RNA against Dmrt1 and/or Trp53. We found that PGCs are highly susceptible to reprogramming induction and that only Trp53 depletion was sufficient to induce pluripotency. In contrast, gonocytes and spermatogonia were resistant to reprogramming by double knockdown of Dmrt1 and Trp53. PSCs derived from PGCs contributed to chimeras produced by blastocyst injection, but some of the embryos showed placenta-only phenotypes suggestive of epigenetic abnormalities of PGC-derived PSCs. These results show that PGCs and gonocytes/spermatogonia have distinct reprogramming potential and also suggest that fresh and cultured SSCs do not necessarily have the same properties.     

Resistance to anthracnose is decreased by tissue culture but increased with longer acclimation in the resistant strawberry cultivar

Inoculation of tissue-cultured plants of strawberry cultivar Ichigochukanbohon-Nou2gou (Nou-2) with the anthracnose pathogen (Glomerella cingulata) results in wilting and plant death, whereas inoculation of strawberry runners grown in greenhouses results in leaf spots, not wilting or death. When tissue-cultured Nou-2 plants were acclimated for 3, 9 or 15 days, plant resistance to anthracnose increased as the acclimation period increased, suggesting that the resistance of Nou-2 may be induced by external factors. To clarify the mechanisms of resistance, we used cDNA microarray analyses to compare gene expressions among tissue-cultured and acclimated plants of the resistant cultivar Nou-2 and the susceptible cultivar Tochiotome. As a result, we identified 18 cDNA clones that were upregulated during acclimation in Nou-2 but not in Tochiotome. In a real-time RT-PCR of the 18 clones, the expression levels of three were significantly higher in acclimated plants of Nou-2. Two of the three clones showed close homology to enzymes related to flavonoid biosynthesis, i.e., leucoanthocyanidin dioxygenase (LDOX, ANS) and UDP-glucosyltransferase, putative (3-GT). The clones spotted onto the cDNA microarrays were rechecked, and 23 nonredundant cDNA clones of 13 enzymes were estimated to be flavonoid biosynthetic enzymes. Most of these clones were upregulated by acclimation in Nou-2.     

Transactivational property of chemicals via medaka glucocorticoid receptor 1b using a stable reporter gene assay

The transactivational property of natural and synthetic chemicals via medaka GR1b was investigated after development of a stable cell line for the reporter gene assay. In our study, cortisol was the most potent agonist among the natural corticoids assayed for potency [EC₅₀ (concentration of agonist provoking a response halfway between the baseline and maximum response) 68 nM] and efficacy. Three artificial corticosteroids, namely, dexamethasone [EC₅₀ 16 nM, relative agonistic activity to cortisol (RAA) 144 %], prednisolone (EC₅₀ 81 nM, RAA 116 %) and clobetasol propionate (EC₅₀ 0.10 nM, RAA 220 %), showed strong agonistic activity and were more potent than the original corticoid, F. All synthetic corticoids used in our study were full agonists. Interestingly, melengestrol acetate, a synthetic progestogen, induced luciferase activity in a dose-dependent manner. Based on its EC₅₀ value and RAA of 29 nM and 57 %, respectively, this molecule was assessed as a partial agonist. None of the other steroids and chemicals assayed in our study induced an agonistic response. In conclusion, we successfully developed a stable reporter gene assay that can be used to assess the transactivational property of glucocorticoid-like chemicals toward medaka GR1b.     

Safety of alternate-day treatment with TS-1TM (tegafur/gimeracil/oteracil) in tumor-bearing dogs: a pilot study

Tegafur is a prodrug of fluoropyrimidine 5-fluorouracil (5-FU), while TS-1^TM is an oral fixed-dose combination of three active drugs, tegafur, gimeracil, and oteracil. This pilot study evaluated the safety of tegafur/gimeracil/oteracil in the treatment of cancers in dogs. Tegafur/gimeracil/oteracil was administered orally at a mean dose of 1.1 mg/kg twice daily on alternate days, Monday-Wednesday-Friday, every week to 11 dogs with tumors. Partial response and stable disease were observed in one dog each, whereas six exhibited progressive disease. Three dogs were not assessed. Adverse events, the most serious being grade 2, were noted in seven dogs. Adverse events were acceptable, and the drug was effective in some dogs. Therefore, tegafur/gimeracil/oteracil may be useful for treating malignant solid tumors in canines.     

Thermogravimetric evaluation of chitin degradation in soil: implication for the enhancement of ammonification of native organic nitrogen by chitin addition

Degradation of chitin, which is an aminopolysaccharide used as a soil amendment, has been often monitored in soil via its degradation products such as carbon dioxide and ammonium. We report here the applicability of thermogravimetry to measure the amount of chitin added to soil. The maximum pyrolysis rate of the upland surface soil of Brown Forest soil supplemented with chitin was strongly correlated with added chitin content (r = 0.999) when the content exceeded 6.0 g kg^?1. The maximum pyrolysis rates of chitin-added soil (around 385°C) was distinctive from those of soil supplemented with cellulose, chitosan, N-acetylglucosamine, and N,N’-diacetylchitobiose (around 340°C, 300°C, 200°C, and 240°C, respectively), indicating the specific detection of chitin. Soil incubation study demonstrated that 60 g kg^?1 chitin added to the soil declined exponentially (r = 0.993) within days and could not be detected at 90 days after the addition of chitin. Total carbon (C) content also decreased within days whereas total nitrogen (N) remained almost constant over the 90 days. The amount of ammonium-N increased in the initial 30 days after the addition of chitin and reached about 3.6 g kg^?1, which corresponded to the amount of N in the added chitin (4.1 g kg^?1) while the amount of nitrite-N and nitrate-N were below 2.0 and 15 mg kg^?1, respectively. Comparison of the measured ammonium-N and total-C contents with those calculated from the measured chitin-content implied that addition of chitin enhanced degradation of native organic compounds in soil.     

Expression levels of taste‐related genes in palate and tongue tip,and involvement of transient receptor potential subfamily M member 5 (TRPM5) in taste sense in chickens

The elucidation of the mechanisms underlying the taste sense of chickens will contribute to improvements in poultry feeding, because the molecular mechanism of chickens’ taste sense defines the feeding behavior of chickens. Here we focused on the gene expressions in two different oral tissues of chickens – the palate, which contains many taste buds, and the tongue tip, which contains few taste buds. Using the quantitative real‐time polymerase chain reaction method, we found that the molecular markers for taste buds of chickens, that is α‐gustducin and vimentin, were expressed significantly highly in the palate compared to the tongue tip. Our analyses also revealed that transient receptor potential subfamily M member 5 (TRPM5), a cation channel involved in taste transduction in mammals, was also highly expressed in the palate compared to the tongue tip. Our findings demonstrated that the expression patterns of these genes were significantly correlated. We showed that the aversion to bitter solution was alleviated by a TRPM5 inhibitor in behavior of chickens. Taken together, our findings enabled us to develop a simple method for screening taste‐related genes in chickens. The use of this method demonstrated that TRPM5 was involved in chickens’ taste transduction, and that a TRPM5 inhibitor can alleviate chickens’ bitter taste perception of feed ingredients.