A2B adenosine and P2Y2 receptors stimulate mitogen-activated protein kinase in human embryonic kidney-293 cells. cross-talk between cyclic AMP and protein kinase c pathways.
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Mitogen-activated protein kinase (MAPK) cascades underlie long-term mitogenic, morphogenic, and secretory activities of purinergic receptors. In HEK-293 cells, N-ethylcarboxamidoadenosine (NECA) activates endogenous A2BARs that signal through Gs and Gq/11. UTP activates P2Y2 receptors and signals only through Gq/11. The MAPK isoforms, extracellular-signal regulated kinase 1/2 (ERK), are activated by NECA and UTP. H-89 blocks ERK activation by forskolin, but weakly affects the response to NECA or UTP. ERK activation by NECA or UTP is unaffected by a tyrosine kinase inhibitor (genistein), attenuated by a phospholipase C inhibitor (U73122), and is abolished by a MEK inhibitor (PD098059) or dominant negative Ras. Inhibition of protein kinase C (PKC) by GF 109203X failed to block ERK activation by NECA or UTP, however, another PKC inhibitor, Ro 31-8220, which unlike GF 109203X, can block the zeta-isoform, and prevents UTP- but not NECA-induced ERK activation. In the presence of forskolin, Ro 31-8220 loses its ability to block UTP-stimulated ERK activation. PKA has opposing effects on B-Raf and c-Raf-1, both of which are found in HEK-293 cells. The data are explained by a model in which ERK activity is modulated by differential effects of PKC zeta and PKA on Raf isoforms. (+info)
Connectin, an elastic protein from myofibrils.
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The elastic protein isolated from myofibrils of chicken skeletal muscle was compared with extracellular non-collagenous reticulin prepared from chicken liver and skeletal muscle. The amino acid compositions of these proteins were similar except that their contents of Phe, Leu, Cys/2, and Hyp were different. The impregnations of the elastic protein and reticulin with silver were also different. The reticulin was not at all elastic. It also differed from reticulin in solubility and antigenicity. It is proposed to call the intracellular elastic protein connectin. (+info)
Collagen fiber arrangement in canine hepatic venules.
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Cell-maceration/scanning electron microscopy, serial sections and scanning electron microscopy of vascular resin casts were employed to demonstrate the arrangement of collagen fibers in the terminal hepatic venules, involving the central, intercalated and collecting veins in dog liver. In cell-maceration specimens, each collagen fiber was observed to run in various directions, forming a sheath with a compact meshwork of collagen fibers. The collagenous meshwork in the hepatic venules was looser than those of the terminal portal venules and hepatic arterioles. Some collagen fibers formed bundles with an elongated spiral arrangement encircling the wall of the terminal hepatic venules. In resin casts, these venules were observed as a twisted configuration caused by spiral collagen bundles. A helical modification of such connective tissue bundles might provide a mechanically stable vascular structure and permit reversible changes in linear and circumferential vascular dimensions at the terminal tributaries of veins. Round or oval pores with diameters of approximately 9 microns were also observed in the sheath of collagen fibers. These pores, together with the relatively loose collagenous meshwork in the hepatic venules, might play a role in lymphocyte migration from these venules into the surrounding tissue and provide high permeability to the venule walls. No such helical configuration and pores were observed in either the portal venules or the hepatic arterioles. (+info)
Immunohistochemical analysis of c-yes and c-erbB-2 oncogene products and p53 tumor suppressor protein in canine mammary tumors.
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In order to evaluate the involvement of c-yes and c-erbB-2 oncogene products, and p53 tumor suppressor protein in canine mammary neoplastic lesions, sections of archived paraffin-embedded samples of 79 mammary tumors were analyzed immunohistochemically using antibodies against human c-yes p62 and c-erbB-2 products and p53. These 79 tumors were divided into 2 groups: 32 benign (2 adenosis, 7 simple adenomas, 14 complex adenomas, and 9 benign mixed mammary tumors) and 47 malignant tumors (26 simple adenocarcinomas, 7 complex adenocarcinomas, 5 solid carcinomas, 2 sclerosing carcinomas, 6 malignant mixed mammary tumors, and 1 malignant myoepithelioma). As a result of immunostaining, 40.6% (13/32) of the benign tumors and 21.3% (10/47) of the malignant tumors expressed the c-Yes oncogene product, ErbB-2 expression was detected in 50% (16/32) of the benign tumors and in 19.1% (9/47) of the malignant tumors. P53 expression was detected in 16% (4/25) of the benign tumors and in 30.6% (11/36) of the malignant tumors. Co-expression of c-Yes and ErbB-2, ErbB-2 and p53, and all 3 products was detected in 6, 1 and 7 tumors, respectively. (+info)
Serotypes and virulence factors of Escherichia coli strains isolated from dogs and cats.
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E. coli strains isolated from urine of dogs and cats with urinary tract infections (UTI) and from feces of healthy one's were serotyped, and the serotypes were correlated with uropathogenic virulence factors. The most prevalent O-serotypes, O4 and O6, were isolated from dogs and cats with UTI. In contrast, O11 and O102 strains were the most frequently found from feces of healthy dogs and cats. Most of type O4 and O6 strains possessed such virulence factors as pil, pap, sfa, hly, and cnf1, while most type O11 and O102 strains pil only or pil and aer. All strains of type O75 possessed afaI and aer. K1 antigen was negative in all strains obtained from UTI. (+info)
Pulsed Doppler ultrasonographic evaluation of portal blood flow in dogs with experimental portal vein branch ligation.
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Portal blood flow was measured using pulsed Doppler ultrasound in 6 dogs before and after left portal vein branch ligation. Mean portal vein blood flow velocity and mean portal vein blood flow were significantly reduced after ligation and the congestion index was increased (p < 0.01). Pulsed Doppler ultrasound studies provide valuable physiological information which may assist the clinician with the diagnosis of canine hepatic circulatory disorders. (+info)
The prevalence of Balantidium coli infection in fifty-six mammalian species.
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A total of 375 fecal samples of 56 mammalian species belonging to 17 families of 4 orders were examined for the detection of Balantidium coli from December 1994 to August 1995. As a result, B. coli was found from 6 species belonging to 4 families of 2 orders (Primates and Artiodactyla) of host animals examined. White-handed gibbon (Hylobates lar), squirrel monkey (Saimiri sciurea) and Japanese macaque (Macaca fuscata) were new hosts for B. coli. All the wild boar (Sus scrofa) and chimpanzee (Pan troglodytes) examined were positive. The highest number of B. coli was obtained from a chimpanzee (1,230/g feces). No B. coli was detected from the animals of orders Rodentia and Carnivora including dogs and cats. The rarity of B. coli infection in breeding animals in Japan. suggests that there is no serious problem in controlling infections. (+info)
A case of canine salmonellosis due to Salmonella infantis.
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A 7-year-old male dog kept outdoors manifested severe watery diarrhea with generalized weakness. Salmonella Infantis was isolated from a fecal sample and the dog recovered soon after medication with ampicillin, to which the isolate was highly sensitive. The present case was diagnosed as S. Infantis infection. Due to the importance of Salmonella in public health, soil samples were collected from the garden where the dog was kept and were examined for Salmonella, Some of them were positive for S. Infantis, however, no Salmonella was isolated from any soil samples collected after thorough disinfection of the surrounded environment. (+info)