α-Conotoxins and α-Cobratoxin Promote,while Lipoxygenase and Cyclooxygenase Inhibitors Suppress the Proliferation of Glioma C6 Cells     

Tatiana I. Terpinskaya  Alexey V. Osipov  Elena V. Kryukova  Denis S. Kudryavtsev  Nina V. Kopylova  Tatsiana L. Yanchanka  Alena F. Palukoshka  Elena A. Gondarenko  Maxim N. Zhmak  Victor I. Tsetlin  Yuri N. Utkin 《Marine drugs》2021,19(2)

Among the brain tumors, glioma is the most common. In general, different biochemical mechanisms, involving nicotinic acetylcholine receptors (nAChRs) and the arachidonic acid cascade are involved in oncogenesis. Although the engagement of the latter in survival and proliferation of rat C6 glioma has been shown, there are practically no data about the presence and the role of nAChRs in C6 cells. In this work we studied the effects of nAChR antagonists, marine snail α-conotoxins and snake α-cobratoxin, on the survival and proliferation of C6 glioma cells. The effects of the lipoxygenase and cyclooxygenase inhibitors either alone or together with α-conotoxins and α-cobratoxin were studied in parallel. It was found that α-conotoxins and α-cobratoxin promoted the proliferation of C6 glioma cells, while nicotine had practically no effect at concentrations below 1 µL/mL. Nordihydroguaiaretic acid, a nonspecific lipoxygenase inhibitor, and baicalein, a 12-lipoxygenase inhibitor, exerted antiproliferative and cytotoxic effects on C6 cells. nAChR inhibitors weaken this effect after 24 h cultivation but produced no effects at longer times. Quantitative real-time polymerase chain reaction showed that mRNA for α4, α7, β2 and β4 subunits of nAChR were expressed in C6 glioma cells. This is the first indication for involvement of nAChRs in mechanisms of glioma cell proliferation.  相似文献   

Short-term microbial responses to soluble inorganic P input in a tropical lowland rain forest in Amazonia     

Yuri W. L. DE SOUSA  Erika BUSCARDO  Carlos A. N. QUESADA  Henrique E. M. NASCIMENTO  Laszlo NAGY 《土壤圈》2021,31(6):964-972

In non-flooded lowland rain forests with low soil phosphorus (P) in parts of Amazonia, P cycling largely occurs via leaf litter recycling by arbuscular mycorrhizal (AM) fungal symbionts. Occasional high input of P into these ecosystems occurs during drought years with increased litterfall. As the length and frequency of drought events are projected to increase in the region, a single-dose nutrient addition experiment was carried out to test how this would impact P cycling. An application rate of 4 kg P ha^-1 was used, which corresponds to twice the amount of litter-derived P in an average year. It was hypothesized that i) the added mineral P would be immobilized by soil microorganisms, leading to measurable increase in soil microbial biomass carbon (C) and P and ii) AM colonization rate would be reduced by the pulse in mineral P available for plant uptake. The results did not support either of our hypotheses. The addition of P did not have an effect on AM root colonization, nor was P immobilized by soil microbiota during the experimental period. The lack of a difference between the control and treatment at our study site could be attributed to the relatively low one-off dose of P applied that did not change either the colonization rate of roots by AM fungi or the amount of soil available labile P. To obtain a mechanistic understanding of the availability, capture, and use of P by plant-symbiont associations in tropical rain forest ecosystems, further integrated studies of the soil-plant system combining long-term nutrient manipulations, modeling, and experimental approaches are required.  相似文献   

Rheological properties and structural changes in raw and cooked abalone meat   总被引：8，自引：0，他引：8  

Xin Gao  Hiroo Ogawa  Yuri Tashiro  Naomichi Iso 《Fisheries Science》2001,67(2):314-320

SUMMARY: In a study of the relationship between structural changes and rheological parameters of raw and cooked abalone meat, abalone Haliotis discus was cooked in boiling water for 3 h, then cut up and separated into cross- and vertical sections. Structural change was observed using a light microscope and scanning electron micrography. The rheological parameters were obtained by stress-relaxation experiments. Microscopic photography revealed that structural change between muscle fibers in both sections of the cooked meat was greater than that in the raw meat. The elastic modulus and rupture strength in both sections of cooked meat showed no difference between the cross- and vertical sections, and were smaller than those for the raw meat. The relaxation time for the cooked meat was also greater than for the raw meat. These results were mainly because of collagen being gelatinized during heating. These changes were also observed by staining collagen and differential scanning calorimetry.  相似文献   

Effects of the estrous cycle on the efficacy of oocyte collection and in vitro embryo production in Duroc‐breed     

Koji Misumi  Yuri Hirayama  Misae Suzuki  Michiko Nakai  Junko Noguchi  Hiroyuki Kaneko  Kazuhiro Kikuchi 《Animal Science Journal》2014,85(2):112-117

Collection efficacy and in vitro embryo developmental ability of oocytes obtained from Duroc‐breed ovary donors at different stages of the estrous cycle (days 6, 12 and 16 after estrus) were performed. The numbers of collected oocytes did not differ significantly among the different estrous cycle groups (total 72–90 oocytes per gilt). However, the blastocyst rates of oocytes collected on days 12 and 16 (9.2% and 19.4%, respectively) were significantly higher than those on day 6 (1.1%). More oocytes were obtained on day 16 from small follicles (<2 mm in diameter; 85.3 oocytes per gilt) than from medium‐sized (≥2–<6 mm) and large (≥6 mm) follicles (17.5 and 12.8 oocytes, respectively). The blastocyst rates in both the medium‐sized and large follicle groups (20.0% and 19.2%, respectively) were significantly higher than that in the small follicle group (6.3%). The blastocyst cell numbers in both the medium‐sized and large follicle groups (39.4 and 43.3 cells, respectively) were significantly higher than that in the small follicle group (30.6 cells). The results suggest that oocyte collection from cycling Duroc pigs can be carried out efficiently from the late luteal to follicular stage. Those oocytes collected from medium‐sized and large follicles show better embryo development.  相似文献   

Histopathological and Immunohistochemical Characterization of Spontaneously Occurring Uterine Deciduomas in Young Adult Rats     

Katsuhiko Yoshizawa  Yuko Emoto  Yuichi Kinoshita  Ayako Kimura  Norihisa Uehara  Takashi Yuri  Nobuaki Shikata  Airo Tsubura 《Journal of toxicologic pathology》2013,26(1):61-66

Uterine deciduomas were found in two female virgin rats, a 15-week-old Lewis rat and a 7-week-old Sprague-Dawley rat. The firm white nodules were located at the base of unilateral uterine horns and were approximately 6 mm and 4 mm in diameter. Histopathologically, the nodules were composed of three areas, each with a distinct type of proliferating cells: large epithelioid decidual cells with round nuclei, prominent nucleoli and abundant eosinophilic cytoplasm (antimesometrial region); compact spindle-shaped cells with oval nuclei and vacuolar cytoplasm (transitional region); and pleomorphic and spiny cells with round to oval nuclei and compact eosinophilic cytoplasm (mesometrial region). These cells proliferated in sheet-like arrangements and transformed into the other types of cells located in surrounding regions. Immunohistochemically, proliferating cells in all regions were strongly positive for proliferating cell nuclear antigen. The proliferating cells were positive for vimentin, and large decidual cells were positive for common acute lymphoblastic leukemia antigen 10, a marker of uterine interstitial cells. Large decidual cells were positive for α-smooth muscle actin and desmin, suggesting differentiation into muscular cells. Progesterone receptor was expressed in all cell types; however, estrogen receptor α was not expressed in the antimesometrial region. These extremely rare tumor-like nodules represent nonneoplastic lesions referred as decidual reactions of endometrial interstitial cells, and their biological behavior is that of a space-occupying benign tumor in young rats. Our cases might provide information as a historical control in toxicity and pharmacological studies in rats.  相似文献   

Early cell enlargement by night-time heating of fruit produce watermelon fruit (Citrullus lanatus Matsum. et Nakai) with high sucrose content     

Youichi Ikeshita  Yuri Kanamori  Nobuyuki Fukuoka  Jun Matsumoto  Yasutaka Kano 《Scientia Horticulturae》2010

To investigate the effects of night-time temperature on cell and fruit size, and sugar accumulation in watermelon fruit, fruits were treated with high night-time temperatures in a greenhouse. The minimum night-time ambient temperature of the heating box (18 °C) was approximately 6 °C higher than that of the control. The length, diameter and weight of heat-treated fruit at the end of heating treatment, 16 days after anthesis (DAA), were significantly greater than that of control fruit, but those at harvesting, 42 DAA, were almost the same in both treatments. Mean cell size of the outer portion of heat-treated fruit at 16 DAA was significantly larger than that of the control. Cell size of the fruits at 42 DAA did not differ between heat-treated and control fruits. Sucrose, glucose and fructose content of fruit at 16 DAA did not differ between heat-treated and control fruit. However, sucrose content of the outer portion of heat-treated fruit was 162% of that of control fruit at 42 DAA. Glucose and fructose contents at 42 DAA did not differ between heat-treated and control fruit, except glucose content of outer portion.  相似文献   

Malignant Mesothelioma in the Thoracic Cavity of a Crj:CD(SD) Rat Characterized by Round Hyalinous Stroma     

Doi T  Kotani Y  Takahashi K  Hashimoto S  Yamada N  Kokoshima H  Tomonari Y  Wako Y  Tsuchitani M 《Journal of toxicologic pathology》2010,23(2):103-106

Spontaneous malignant mesothelioma was found in a 104-week-old male Crj:CD(SD) rat. The tumor was scattered on the surface of the lung, heart, mediastinal pleura and thoracic wall and metastasized to the alveolar septa. Histopathologically, small flattened or cuboidal tumor cells proliferated with stroma, formed almost normal papillary structures and reacted positively to colloidal iron stain and immunohistochemical staining for mesothelin. Round hyalinous stromata were pronounced, which is a characteristic feature, and the possible reason for this is as follows; at first, a small amount of collagen fibers was formed in the center of the clusters of several tumor cells, and then the cell clusters expanded like balloons with an increase in the collagen fibers.  相似文献   

Stability of the regulatory T cell lineage in vivo     

Rubtsov YP  Niec RE  Josefowicz S  Li L  Darce J  Mathis D  Benoist C  Rudensky AY 《Science (New York, N.Y.)》2010,329(5999):1667-1671

Tissue maintenance and homeostasis can be achieved through the replacement of dying cells by differentiating precursors or self-renewal of terminally differentiated cells or relies heavily on cellular longevity in poorly regenerating tissues. Regulatory T cells (T(reg) cells) represent an actively dividing cell population with critical function in suppression of lethal immune-mediated inflammation. The plasticity of T(reg) cells has been actively debated because it could factor importantly in protective immunity or autoimmunity. By using inducible labeling and tracking of T(reg) cell fate in vivo, or transfers of highly purified T(reg) cells, we have demonstrated notable stability of this cell population under physiologic and inflammatory conditions. Our results suggest that self-renewal of mature T(reg) cells serves as a major mechanism of maintenance of the T(reg) cell lineage in adult mice.  相似文献   

Trichomoniasis in finches from the Canadian Maritime provinces — An emerging disease     

María J. Forzán  Rapha?l Vanderstichel  Yuri F. Melekhovets  Scott McBurney 《The Canadian veterinary journal. La revue veterinaire canadienne》2010,51(4):391-396

Trichomoniasis was diagnosed in multiple incidents of mortality in wild purple finch (Carpodacus purpureus) and American goldfinch (Carduelis tristis) in the Canadian Maritimes. Birds exhibited regurgitation, emaciation, and hyperplastic oropharyngitis, ingluvitis, and esophagitis. Trichomonas gallinae was identified by histopathology and polymerase chain reaction (PCR). Trichomoniasis (trichomonosis) is an emerging disease in wild finches of eastern Canada.  相似文献   

Relationship between the water molecules in fish-meat gel and the gel structure     

Lujia Luo  Yuri Tashiro  Hiroo Ogawa 《Fisheries Science》2012,78(5):1137-1146

To elucidate the structure of the network of the water retention mechanism of fish-meat gel, the microscopic relationship between the water content and viscoelasticity was investigated, and the specific surface area (S) where the water molecules are adsorbed was also measured. The gel structures of fish-meat, actomyosin (AM), and myosin (M) were investigated. In the fish-meat gel, as the water content increased, the number of network chains (??) decreased and the molecular weight between the cross-linking points (M _e) increased. At 10?% salinity and approximately 79?% moisture, ?? decreased to a minimum and M _e began to increase remarkably. In addition, when the moisture increased to 78?%, S increased about 1.5 times and the elasticity decreased significantly, indicating that this level of water content is the limit for sufficiently forming a gel structure in fish-meat gel. In the AM and M gels, M _e and S were similar to those observed in the fish-meat gels. When the moisture content increased, they also increased, regardless of the salt concentration. This result suggests that the size of the network was enlarged or that the network chains were cleaved.  相似文献