细化搜索
结果 171-180 的 321
Phospholipase C-mediated vasorelaxing action of melatonin in rat isolated aorta
2005
Kim, S.J. (Chonbuk National University, Jeonju, Republic of Korea) | Baek, S.S. (Chonbuk National University, Jeonju, Republic of Korea) | Kang, H.S. (Chonbuk National University, Jeonju, Republic of Korea) | Kim, J.S. (Chonbuk National University, Jeonju, Republic of Korea), E-mail: kimjs@chonbuk.ac.kr
Melatonin, the principal hormone of the vertebral pineal gland, participates in the regulation of cardiovascular system in vitro and in vivo. However, the effects of melatonin on vascular tissues are still vague. The aim of this study was to assess the relationship between phospholipase C (PLC) and nitric oxide synthase (NOS)/cyclic guanosine 3',5'-monophosphate (cGMP) signaling cascade in the relaxatory action of melatonin in isolated rat aorta. Melatonin induced a concentration-dependent relaxation in phenylephrine (PE)- and KCl-precontraceted endothelium intact (+E) aortic rings.
显示更多 [+] 显示较少 [-]Expression of caveolin-3 as positive intracellular signaling regulator on the development of hypertrophy in cardiac tissues
2005
Kim, J.H. (Gyeongsang National University, Jinju, Republic of Korea) | Han, J. (Inje University, Busan, Republic of Korea) | Kim, Y.K. (Inje University, Gimhae, Republic of Korea) | Hong, Y.G. (Inje University, Busan, Republic of Korea), E-mail: yonghong@inje.ac.kr | Yang, Y.A. (Inje University, Gimhae, Republic of Korea)
We have examined distribution and expression of caveolin-3 (cav-3), one of three caveolin isoforms from 16-wks-old spontaneously hypertensive rats (SHR) compared with age-matched control wistar-kyoto (WKY) rats. The expression of cav-3 was increased, whereas expression of PKB/Akt and calcineurin (Cn) was not changed in cardiac tissues of SHR compared to WKY rats. Interestingly, expression of cav-3, PKB/Akt and Cn were decreased in plasma membrane fraction in SHR compared to WKY rats. In H9c2 cardiomyoblast cells treated with phenylephrine (50 μM, 48hr) or isoproterenol (10 μM, 48hr), the expression of cav-3 was markedly enhanced compared to nontreated cells.
显示更多 [+] 显示较少 [-]Standardization of an enzyme-linked immunosorbent assay for detection of antibody to avian reticuloendotheliosis virus
2005
Sung, H.W. (Kangwon National University, Chunchon, Republic of Korea), E-mail: sunghw@kangwon.ac.kr | Lee, S.J. (Kangwon National University, Chunchon, Republic of Korea)
Enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to reticuloendotheliosis virus (REV) at single serum dilution was standardized. REV HI, one of the Korean field isolates, was inoculated into chicken embryo fibroblast (CEF) cells and was harvested from the culture fluids and cells after 10 to 12 days. Viruses were purified by centrifugation at the 107,000×g for 12 hours on 20, 30, 45% (W/V) sucrose gradient. Virus specific fraction was collected and used as ELISA antigen. To standardize ELISA, the optimal concentration of coating antigen (1 ㎍/well) and conjugate (1/1000) was determined by corrected OD (OD value of positive serum-OD value of negative serum) and P/N ratio (OD value of positive serum/OD value of negative serum).
显示更多 [+] 显示较少 [-]A case of canine patent ductus arteriosus showed favorable therapeutic response by surgery combined with needle-acupuncture therapy
2005
Kim, K.S. (Withpet Animal Clinic, Seoul, Republic of Korea) | Kim, B.Y. (Noah Animal Clinic, Seoul, Republic of Korea) | Kim, T.H. (Kim Tae-Hwa Animal Clinic, Seoul, Republic of Korea) | Kim, W.B. (Gaepo Animal Clinic, Seoul, Republic of Korea) | Liu, Jian Zhu (Chungnam National University, Daejeon, Republic of Korea) | Lee, J.Y. (Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan) | Rogers, Philip A.M. (Teagasc, Grange Research Centre, Dunsany, Co., Meath, Ireland) | Kim, D.H. (Chungnam National University, Daejeon, Republic of Korea), E-mail: dhkim@cnu.ac.kr
A 6-month-old male Poodle was referred with chief complaint of dysponea and cough. Cyanosis was not detected. This dog was diagnosed as a case of canine patent ductus arteriosus (PDA) by X-ray and ultrasonography. Diuretics and bronchodialators were administered for 4 weeks. Clinical symptoms were not improved. Thoracotomy was done at right recumbent position. The length of ductus arteriosus was 8 mm and the diameter was 6 mm, respectively. Double ligation was performed in surgery. Continuous cardiac murmur, cough and strong femoral pulsation were disappeared after surgery. The diameters of the pulmonary artery and vein found to normal by X-ray on 10 days after operation.
显示更多 [+] 显示较少 [-]Electrocardiographic surrogates of structural myocardial alterations in the Dorper sheep heart
2005
J. Ker | E.C. Webb
In this study we evaluated the validity of well-known human electrocardiographic markers of myocardial pathology in Dorper sheep. These markers include: the duration of the QRS complex of premature ventricular complexes (PVCs), the presence of notching of the QRS complex of PVCs and change of the ST-segment of PVCs. It was shown that these three electrocardiographic phenomena correlate with myocardial pathology in the hearts of Dorper sheep. We also describe a new electrocardiographic indicator of myocardial pathology, namely an increase in the frequency of cardiac memory T waves as a new electrocardiographic surrogate for myocardial pathology in the hearts of Dorper sheep.
显示更多 [+] 显示较少 [-]Survey of nematophagous fungi in South Africa : research communication
2005
D.T. Durand | H.M. Boshoff | L.M. Michael | R.C. Krecek
Three hundred and eighty-four samples of leaf litter, soil, faeces from domestic and game animals, compost and aqueous cultures of infective nematode larvae contaminated with unidentified fungi were plated out on water agar, baited with pure infective larvae of Haemonchus contortus, incubated and examined for the presence of nematophagous fungi. Duddingtonia flagrans was isolated from five samples, and 73 samples were positive for other nematophagous fungi.
显示更多 [+] 显示较少 [-]Epidemiological studies of amphistome infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe
2005
D.M. Pfukenyi | S. Mukaratirwa | A.L. Willingham | J. Monrad
During the period between January 1999 and December 2000, the distribution and seasonal patterns of amphistome infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe were determined through monthly coprological examination. Cattle faecal samples were collected from 12 and nine dipping sites in the highveld and lowveld communal grazing areas, respectively. Patterns of distribution and seasonal fluctuations of intermediate host-snail populations and the climatic factors influencing the distribution were also determined by sampling at monthly intervals for a period of 24 months (November 1998 to October 2000) in six dams and six streams in the highveld and in nine dams in the lowveld communal grazing areas. Each site was sampled for relative snail density and the vegetation cover and type, physical and chemical properties of water, and mean monthly rainfall and temperature were recorded. Aquatic vegetation and grass samples 0-1 m from the edges of the snail habitats were collected monthly to determine the presence or absence of amphistome metacercariae. Snails collected at the same time were individually checked for the emergence of larval stages of amphistomes. A total of 16 264 (calves 5 418, weaners 5 461 and adults 5 385) faecal samples were collected during the entire period of the study and 4 790 (29.5 %) of the samples were positive for amphistome eggs. For both regions the number of animals positive for amphistome eggs differed significantly between the 2 years, with the second year having a significantly higher prevalence (P < 0.01) than the first year. Significantly higher prevalences were found in the highveld compared to the lowveld (P < 0.001), for adult cattle than calves (P < 0.01), and in the wet over the dry season (P < 0.01). Faecal egg output peaked from October to March in both years of the study. Bulinus tropicus, Bulinus forskalii and Biomphalaria pfeifferi were recorded from the study sites. The main intermediate host for amphistomes was B. tropicus with a prevalence of infection of 8.5 %. However, amphistome cercariae were also recorded in Biom. Pfeifferi and B. forskalii. Amphistome cercariae were recorded from both the highveld and lowveld areas with peak prevalence during the post-rainy season (March to May). Metacercariae were found on herbage from the fringes of the snail habitats between February and August, with most of the metacercariae concentrated on herbage 0-1 m from the edges of the habitats. Based on the epidemiological findings a control programme was devised. From this study, large burdens of immature flukes could be expected in cattle during the dry months. Since adult cattle would be resistant to the pathogenic effects of the migrating immature amphistomes the target for control would be young animals being exposed to the infection for the first time. Therefore, the first anthelmintic treatment can be administered in calves in mid June when maximum migration of immature amphistomes starting 3-4 weeks after infection in the early dry season would be expected. A second treatment could be given in late July or early August to remove potentially dangerous burdens of immature flukes acquired later in the dry season. Where resources permit, another strategy would be to treat against the mature flukes in March or April in order to reduce the number of eggs deposited on pastures and the opportunity for infection of the intermediate host snails. To reduce cercarial shedding by the intermediate host snails molluscicides can also be applied during the peak transmission periods (April/May and August/September).
显示更多 [+] 显示较少 [-]Serological evidence of chicken anaemia virus infection in Nigerian indigenous chickens : research communication
2005
B.O. Emikpe | D.O. Oluwayelu | O.G. Ohore | O.A. Oladele | A.T. Oladokun
Serum samples from 20 out of 180 (11.1 %) apparently healthy Nigerian indigenous chickens were negative for antibodies against chicken anaemia virus using the enzyme-linked immunosorbent assay (ELISA). Of the 160 positive sera (88.9 %), 12 (7.5 %) had titres ranging from 1 500-3 000, 46 (28.8 %) had titres from 3 000-5 000 while 102 (63.8 %) had titres between 5 000-11 000. The overall mean titre value was 5 845 + 2 402. This appears to be evidence of a natural outbreak of the infection since the chickens had no history of vaccination against any poultry disease.
显示更多 [+] 显示较少 [-]Viral and bacterial diseases in livestock in Mongolia
2005
Odontsetseg, N. (Hokkaido Univ., Sapporo (Japan)) | Mweene, A.S. | Kida, H.
5371 This review focuses on the status of infectious diseases that are serious for animal health and have adverse economic effects in Mongolia. Data presented here are limited due to the lack of published or other easily available documents. Foot-and-mouth disease continues to cause substantial economic losses as exemplified by the outbreak of infection with serotype O PanAsia lineage virus. In the case of the 2001 outbreak, a 65%reduction in export revenues was recorded. In order to ascertain the free status of Mongolia from rinderpest, sero-epidemiological surveillance has been carried out since 2001. In 2004, Mongolia was certified free from rinderpest by Office Interna-tional des Epizooties (OIE). A sharp rise in both animal and human brucello-sis incidence has become a serious problem. Rabies and anthrax remain endemic with occasional human cases. Other prevailing infectious diseases are contagious pustular dermatitis, contagious agalactia, enterotoxemia and ¡pas-teurellosis. The current programs for the control of infectious diseases in livestock in Mongolia lack a definite policy that would enable rapid implementation. A large-scale surveillance of infectious diseases in animals and management of appropriate preventive measures are urgently required in Mongolia.
显示更多 [+] 显示较少 [-]Antigenotoxic effect of Pleurotus cornucopiae extracts on the mutagenesis of Salmonella typhimurium TA98 elicited by benzo(a)pyrene and oxidative DNA lesions in V79 hamster lung cells
2005
Bohi, K.M.E. (Hokkaido Univ., Sapporo (Japan)) | Sabik, L. | Muzandu, K. | Shaban, Z. | Soliman, M. | Ishizuka, M. | Kazusaka, A. | Fujita, S.
Pleurotus cornucopiae (PC) mushroom with a brilliant yellow pileus is found in the field and known in Japan as Tamogi dake mushroom. The purpose of this paper is to investigate the mechanism of the antimutagenic effect of PC mushroom using both the Ames test and Comet assay. We have found a strong inhibitory effect of both aqueous and organic PC extracts on the mutagenicity elicited by benzo[a]pyrene (B[a]P). This inhibition was dose- dependent in reaction mixtures containing cytosolic and microsomal fractions (S-9) from untreated rat liver as well as in those containing S-9 from aryl hydrocarbon receptor (Au) ligand of Sudan III-treated rats. Sudan III was a potent inducer of cytochrome P450 1A (CYP1A) activity. We treated rats with Sudan III to enhance the metabolic activation of B[a]P by the S-9 fraction. To explain whether this antimutagenicity was due to the inhibition of CYP1A activity that metabolically activates B[a]P, we tested the effects of the extracts on activities of CYP1A1 and CYP1A2, represented by ethoxyresorufin Odeethylase (EROD) and methoxyresorufin Odemethylase (MROD), respectively. Both aqueous and organic extracts inhibited EROD activity at all dose levels, while the inhibitory effect was only observed at high doses with regard to MROD activity. Furthermore, pre-treatment of Chinese hamster V79cells with PC extracts significantly reduced H2O2 - induced-DNA damage, indicating that PC extracts provide a protective effect against oxidative DNA damage. These results indicate that whole-mushroom extracts contain compounds that may inhibit the metabolic activation of B[a]P by CYP1A1 as well as prevent oxidative DNA damage.
显示更多 [+] 显示较少 [-]