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111.
Regions believed to be refugia are known to have lineages indigenous to the regions. The Izu Peninsula, where genus Fagus existed during the last glacial period, was focused on to survey chloroplast DNA of Japanese beech (Fagus crenata Blume) that grew there. DNA sequence analysis of chloroplast genome regions of about 14 kb revealed two new haplotypes, O and E-1, in F. crenata populations in the Izu Peninsula and adjacent regions. Both haplotypes were conceivably derived from haplotype E. The result of the genetic analysis in this study in combination with the result of pollen analyses performed in the past clearly showed that refugia for F. crenata existed in the Izu Peninsula, and that F. crenata now in growth are lineages indigenous to the region.  相似文献   
112.
In the current study, milk protein variation was examined in cattle (Bos indicus), mithun (Bos frontalis), yak (Bos grunniens) and their hybrid populations in Bhutan to estimate genetic variability, conduct genetic characterization and assess the possibility of gene flow between mithun and cattle. Isoelectric focusing of 372 milk samples from 11 populations detected four molecular types of β‐lactoglobulin (A, B, E and M), five molecular types of αS1‐casein (A, B, C, E and X) and three molecular types of k‐casein (A, B and X). Mithun and yak shared alleles but were found to exhibit different allele frequencies for the proteins studied. The degree of genetic variability within populations was measured by average heterozygosity and ranged from 24–40% in cattle, 26% for yak and 33% for mithun. We also resolved the traditional mithun and cattle hybridization system via principal component analysis. Our results suggested secondary introgression of mithun genes to the village Thrabum population, and a close genetic relationship between Bhutanese indigenous cattle and Indian cattle.  相似文献   
113.
Cinnamomum camphora (L.) Presl is an evergreen broad-leaved tree of the Lauraceae family, widely distributed in the sub-tropical areas in the south of China and used as a virescent tree in urban gardens and streets in Shanghai for its beautiful shape and intensive stress-resistance. However, yellowing of C. camphora in recent years casts doubt about its significance. We believe the green-leaved and yellow-leaved C. camphora might be two different ecotypes, and tentatively refer to the green-leaved C. camphora as C. camphora f. viridis f. nov (CCV) and the yellow-leaved as C. camphora f. flavus f. nov (CCF). We studied their differences and arrived at the following conclusions: 1) compared with CCF, the area of lamina of CCV is significantly larger and the amount of chlorophyll (Chl) significantly higher; 2) the lamina and palisade tissues of CCV are significantly thicker than those of CCF, but its cuticle is significantly thinner; 3) the shape of the stomata of CCV is different from that of the CCF; the stomatal density and stomatal index of CCV are significantly lower than those of CCF. These results show that C. camphora might evolve adaptive differentiation in some aspects which can be used in virescence in urban streets and gardens.  相似文献   
114.
Clostridium botulinum types C and D are related to avian and mammalian botulism. Bovine botulism occurred at various farms from 2004 to 2007 in Japan. Since culture supernatants of isolates from cases of bovine botulism were neutralized completely and partially with type D and C antitoxins, respectively, we attempted to confirm the nucleotide sequences of the neurotoxin gene in isolates. The neurotoxin gene comprised two-thirds of the type D neurotoxin gene and one-third of the type C neurotoxin gene, indicating that the neurotoxin of bovine isolates is a mosaic of type D and C neurotoxins, D/C mosaic neurotoxin. We prepared four sets of primers to differentiate the genes of the mosaic and authentic forms with PCR. The results showed that all bovine botulism-related isolates possess the gene for the D/C mosaic form. Pulsed-field gel electrophoresis analysis demonstrated that isolates from bovine botulism which had occurred between 2004 and 2007 were genetically homologous, except for the isolate from one area. We further examined the biological and antigenic properties of the D/C mosaic neurotoxin, which was found to exhibit the highest lethal activity in mice compared with other types of neurotoxins. In the D/C mosaic neurotoxin, three epitopes recognized by monoclonal antibodies that specifically react to and neutralize the toxin were located in the carboxyl-terminal domain of the heavy chain. These results indicate that D/C mosaic neurotoxin is a pathogenic agent causing bovine botulism and has unique characteristics different from other type C and D neurotoxins.  相似文献   
115.
In the present study, we investigated the hydrothermal treatment of titanium with divalent cation solutions and its effect in promoting the adhesion of gingival epithelial cells and fibroblasts in vitro. Gingival keratinocyte-like Sa3 cells or fibroblastic NIH3T3 cells were cultured for 1 h on experimental titanium plates hydrothermally-treated with CaCl(2) (Ca) or MgCl(2) (Mg) solution, or distilled water (DW). The number and adhesive strengths of attached cells on the substrata were then analyzed. The number of Sa3 cells adhering to the Ca- and Mg-treated plates was significantly larger than in the DW group, but the strength of this adhesion did not differ significantly between groups. In contrast, NIH3T3 cell adhesion number and strength were increased in both the Ca and Mg groups compared to the DW group. Fluorescent microscopic observation indicated that, in all groups, Sa3 had identical expression levels of integrin β4 and development of actin filaments, whereas NIH3T3 cells in the Ca and Mg groups displayed much stronger punctate cytoplasmic signals for vinculin and more bundle-shaped actin filaments than cells in the DW group. As a result, it was indicated that the hydrothermal treatment of titanium with Ca or Mg solution improved the integration of soft tissue cells with the substrata, which may facilitate the development of a soft tissue barrier around the implant.  相似文献   
116.
Little information is available on the relationship between computed tomography (CT) imaging findings and the pathologic diagnosis of canine hepatic tumors. Our purpose was to clarify the characteristic features of CT findings in liver tumors in dogs. Data from 33 dogs with either a hepatocellular carcinoma, n = 14, hepatocellular adenoma, n = 14, or nodular hyperplasia, n = 5 were summarized from medical records. CT features for each histologic diagnosis were characterized and analyzed statistically. Common findings in hepatocellular carcinoma included central (79%, P = 0.0030) and marginal enhancement (93%, P = 0.00043) in the arterial phase, cyst-like lesions (93%), capsule formation (93%), and hypoattenuation in the portal (86%), and equilibrium phases (93%). Hepatic adenoma was characterized by a characteristic diffuse enhancement pattern during the arterial phase (57%, P = 0.013), which was also found in nodular hyperplasia (60%), but never in hepatocellular carcinoma. Nodular hyperplasia was less likely to have a capsule structure (20%, P = 0.0087). Mass size was significantly smaller in nodular hyperplasia than in hepatocellular carcinoma and hepatic adenoma (P = 0.0033 and 0.038, respectively). Hyperattenuation in the arterial and the portal phase i.e. contrast retention, was more frequent in hepatic adenoma than in the other groups (P = 0.037 and 0.037, respectively). Nodular hyperplasia was more frequently isoattenuating in the equilibrium phase (P = 0.043).  相似文献   
117.
Cellular activation and functional cell surface markers were evaluated during experimentally-induced endotoxemia in healthy horses. Eight healthy adult horses were infused a low dose of endotoxin (lipopolysaccharide from Escherichia coli O26: B6, 30 ng/kg of body weight, IV) and five control horses were given an equivalent volume of sterile saline solution. Venous blood samples were collected for flow cytometric analysis of peripheral blood mononuclear cells (PBMCs) and to measure plasma endotoxin concentrations. Clinical signs of endotoxemia were recorded at 10, 20, 30, 40, 50 min, 1, 2, 3, 4, 8, 16, 24 and 48 hr after endotoxin or saline solution administration. Clinical findings characteristic of endotoxemia (tachycardia, tachypnea, increased rectal temperature, and leukopenia) occurred transiently in all horses administered endotoxin; however, plasma endotoxin concentrations were detectable in only 50% (4/8) of the endotoxin-infused horses. The percentage of CD4(+), CD5(+), and CD8(+) cells decreased while the percentage of CD14(+), IgM(+), and MHC class II(+) cells increased significantly after endotoxin infusion. Alterations in the immunophenotype of PBMCs from horses with experimentally-induced endotoxemia were associated with changes in vital signs, indicating that endotoxin altered the immuno balance.  相似文献   
118.
Tick-borne diseases occurring in Zambia are assuming more importance as they continue to be a major economic problem not only in Zambia, but in many parts of Eastern, Southern and Central Africa. The current control methods, which include the use of toxic acaricides to kill ticks, and the virulent sporozoite infection and treatment method have limitations. Recombinant vaccines, currently in their experimental stages, offer hope for the future. The use of acaricides is hampered by the development of acaricide resistance and live vaccines are dependent on cold chain facilities, which are a formidable obstacle in the poorly developed infrastructure in parts of Zambia where the vaccine is most needed. Amidst these drawbacks are the results of the recent research on parasites and vector recombinant vaccines which promise to circumvent these problems. The history, current status and attitudes regarding the control of these diseases, taking into account their complexity, are reviewed. The establishment of the well-designed Central Veterinary Research Institute (CVRI) and Japanese International Cooperation Agency (JICA) sponsored veterinary school, both have a potential for high quality research, with access to a wealth of specimens a veritable goldmine of research material. It is thus hoped that this review will stimulate the desire to maximize the value of the tick and tick-borne disease research in both Zambia and the international research community.  相似文献   
119.
The potential role of Boophilus microplus as a natural tick vector of Babesia equi and Babesia caballi in Brazilian horses was assessed using nested polymerase chain reaction (PCR)-based marker assay. B. equi merozoite-specific 218bp gene fragment was detected in almost 96% of horse blood samples, and 45.3-62.5% of females, eggs, larvae, and nymphs of B. microplus collected from 47 horses at Campo Grande in the State of Matto Grosso, Brazil. Except for the partially-fed female ticks, the B. caballi-specific 430bp gene fragment was amplified from horse blood samples, and all developmental stages. Parasite DNA from both species was detected in horse blood samples and B. microplus, with the preponderance of B. equi DNA. No DNA samples were positive solely for B. caballi parasite. Only 32% of the Giemsa-stained thin blood smears were positive for Babesia parasites, as against detection of B. equi parasite DNA in 95.7% of the blood samples by nested PCR. We have obtained molecular evidence that strengthens earlier experimental and ultrastructural studies in Brazil incriminating B. microplus as a natural vector of B. equi, and possibly of B. caballi. The detection of B. equi and B. caballi DNA in eggs and larvae of B. microplus is likewise suggestive of the possibility of both transovarial and transstadial parasite transmission in this tick vector.  相似文献   
120.
Neospora caninum is a recognized protozoan parasite of a wide range of mammalian hosts, and was reported for the first time in 1988. The isolation of its oocysts in dog's faeces in 1998 led to its establishment as a parasitic species undergoing typical coccidian life cycle. Infection with N. caninum causes paralysis and death in young livestock and companion animals, and is associated with abortions and stillbirth in cattle, and neurologic disease in calves. Considering the economic and agricultural importance of neosporosis, there is the urgent need to develop biological control measures aimed at preventing its transmission, infection, as well as reducing severity of the disease. In this paper, we have reviewed the progress made to date on the parasite-host immunology and on vaccine development including its prospects, and discussed possible strategies in the formulation of vaccine(s) against neosporosis.  相似文献   
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