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991.
992.
While the presence of pinworm eggs in archaeological samples has been reported by many researchers in the New World, those have been detected very scarcely in the Old World, especially in East Asian countries. In fact, many parasite species were recovered from the archeological remains in Korea, eggs of Enterobius vermicularis had not been found. Recently, a female mummy buried in the 17th century was discovered in the Joseon tomb from Dangjin-gun, Chungcheongnam-do, Korea. After rehydration process for 12 days, investigations were carried on the luminal surface of the colon. From them, 3 eggs of E. vermicularis were recovered. They were elliptical, transparent with a thin egg shell, 50.3±5.2 μm (length) and 28.2±3.9 μm (width) in size. This is the first discovery of E. vermicularis eggs in East Asia.  相似文献   
993.
Species identification of Taenia tapeworms was performed using morphologic observations and multiplex PCR and DNA sequencing of the mitochondrial cox1 gene. In 2008 and 2009, a total of 1,057 fecal samples were collected from residents of Kongwa district of Dodoma region, Tanzania, and examined microscopically for helminth eggs and proglottids. Of these, 4 Taenia egg positive cases were identified, and the eggs were subjected to DNA analysis. Several proglottids of Taenia solium were recovered from 1 of the 4 cases. This established that the species were T. solium (n = 1) and T. saginata (n = 3). One further T. solium specimen was found among 128 fecal samples collected from Mbulu district in Arusha, and this had an intact strobila with the scolex. Phylegenetic analysis of the mtDNA cox1 gene sequences of these 5 isolates showed that T. saginata was basal to the T. solium clade. The mitochondrial cox1 gene sequences of 3 of these Tanzanian isolates showed 99% similarity to T. saginata, and the other 2 isolates showed 100% similarity to T. solium. The present study has shown that Taenia tapeworms are endemic in Kongwa district of Tanzania, as well as in a previously identified Mbulu district. Both T. solium isolates were found to have an "African/Latin American" genotype (cox1).  相似文献   
994.
Human alveolar echinococcosis (AE), a hepatic disorder that resembles liver cancer, is a highly aggressive and lethal zoonotic infection caused by the larval stage of the fox tapeworm, Echinococcus multilocularis. E. multilocularis is widely distributed in the northern hemisphere; the disease-endemic area stretches from north America through Europe to central and east Asia, including northern parts of Japan, but it has not been reported in Korea. Herein, we represent a first case of AE in Korea. A 41-year-old woman was found to have a large liver mass on routine medical examination. The excised mass showed multinodular, necrotic, and spongiform appearance with small irregular pseudocystic spaces. Microscopically, the mass was composed of chronic granulomatous inflammation with extensive coagulation necrosis and parasite-like structure, which was revealed as parasitic vesicles and laminated layer delineated by periodic acid-Schiff (PAS) stain. Clinical and histologic features were consistent with AE. After 8 years, a new liver mass and multiple metastatic pulmonary nodules were found and the recurred mass showed similar histologic features to the initial mass. She had never visited endemic areas of AE, and thus the exact infection route is unclear.  相似文献   
995.
Adults of Maritrema obstipum (Digenea: Microphallidae) were found in the intestines of 4 species of migratory birds, including the sanderling (Crocethia alba), Kentish plover (Charadrius alexandrines), Mongolian plover (Charadrius mongolus), and red-necked stint (Calidris ruficollis), collected from Yubu Island, Chungcheongnam-do, Korea. The worms of were 451 × 265 μm in size, and were easily identifiable as Maritrema species by the presence of the cirrus sac, and the ring-like distribution of the vitellaria. More specifically, the ejaculatory duct curved posteromedially, and the 2 parts of vitelline follicles were found to be distinct at the posterior end. The eggs were brown-colored, and 19.8 × 12.3 μm in size. All these findings implicated M. obstipum as the pertinent species of the worms. Beside these, adult worms of Gynaecotyla squatarolae, Parvatrema duboisi, and Acanthoparyphium sp. were also discovered. This is the first report establishing migratory birds as the natural definitive hosts for M. obstipum.  相似文献   
996.
We give an explicit construction to solve a conjecture of Mike Steel and David Penny that any phylogeny involving N taxa can be recovered unambiguously using on the order of log N binary characters and the method of maximum parsimony. Biologically, this means that homoplasy need not be a deterrent to parsimony methods. Some patterns of homoplasy are phylogenetically informative and can exponentially reduce the amount of data needed to resolve a phylogeny.  相似文献   
997.
Ezratty EJ  Stokes N  Chai S  Shah AS  Williams SE  Fuchs E 《Cell》2011,145(7):1129-1141
Ciliogenesis precedes lineage-determining signaling in skin development. To understand why, we performed shRNA-mediated knockdown of seven intraflagellar transport proteins (IFTs) and conditional ablation of Ift-88 and Kif3a during embryogenesis. In both cultured keratinocytes and embryonic epidermis, all of these eliminated cilia, and many (not Kif3a) caused hyperproliferation. Surprisingly and independent of proliferation, ciliary mutants displayed defects in Notch signaling and commitment of?progenitors to differentiate. Notch receptors and Notch-processing enzymes colocalized with cilia in wild-type epidermal cells. Moreover, differentiation defects in ciliary mutants were cell autonomous and rescued by activated Notch (NICD). By contrast, Shh signaling was neither operative nor required for?epidermal ciliogenesis, Notch signaling, or differentiation. Rather, Shh signaling defects in ciliary mutants occurred later, arresting hair follicle morphogenesis in the skin. These findings unveil temporally and spatially distinct functions for primary cilia?at the nexus of signaling, proliferation, and differentiation.  相似文献   
998.
Histamine, an important chemical mediator, has been shown to regulate inflammation and allergic responses. Stimulation of histamine receptors results in a significant increase in cytoplasmic Ca2+, which could be mediated by inositol trisphosphate (IP3)-dependent store-operated Ca2+ channels (SOC). However, the link between histamine-mediated signaling and activation of inflammatory genes such as cyclooxygenase 2 (COX-2) is still unknown. Our study indicated that the COX-2 protein was highly expressed in human lung cancer cells. Following stimulation with 10 μM of histamine, both store-operated Ca2+ entry (SOCE) and COX-2 gene expression were evoked. Histamine-mediated COX-2 activation can be prevented by 2-APB and SKF-96365, SOC channel inhibitors. In addition, deletion analysis of the COX-2 promoter suggested that the region between −80 bp and −250 bp, which contains NFκB binding sites, is the key element for histamine-mediated signaling. Knocking down ORAI1, one of the essential molecules of store-operated calcium channels, attenuated histamine-mediated COX-2 expression and NFκB activation. These results indicated that ORAI1-mediated NFκB activation was an important signaling pathway, responsible for transmitting histamine signals that trigger inflammatory reactions.  相似文献   
999.
Metallothionein MTT1 and MTT2 from Tetrahymena thermophila are sulfydryl-rich proteins that can bind to and are inducible by heavy metals such as mercury, cadmium, zinc, and copper. However, little is known about the induction and binding of T. thermophila metallothionein by trivalent metals. In this study, we found that 10–80 μM La3+ can promote Tetrahymena cells proliferation, and fluorescence spectrum analysis showed that La3+ can enter T. thermophila cells. Real-time quantitative polymerase chain reaction showed La3+ induced the expression of MTT1 and MTT2. Furthermore, Fluorescence analysis indicated La3+ bind to MTT1 and MTT2. These results implied that La3+ could interact with MTT1 and MTT2 via aspartic or glutamic acid oxygen atoms.  相似文献   
1000.
Although polyclonal regulatory T cells (Tregs) that once expressed Foxp3 (ex-Tregs) derived from Foxp3(+) Tregs have been described in homeostatic and autoimmune settings, little is known regarding the influence of the tumor environment on ex-Treg development. After adoptive transfer of HY-specific green Tregs (peripheral or thymic) to Rag2(-/-) B6 female mice bearing syngeneic HY-expressing MB49 tumors, a significant fraction rapidly lost expression of Foxp3. On the second transfer to a Rag2(-/-) B6 male environment, these ex-Tregs expanded strongly, whereas Tregs that maintained expression of Foxp3 expression did not. Both FACS and quantitative real-time-PCR analysis revealed that ex-Tregs upregulated genes characteristic of a Th1 effector-memory phenotype including IFN-γ and downregulated a panel of Treg-specific genes. Peripheral HY-specific green Tregs were adoptively transferred to Rag2(-/-) B6 male mice, to dissect the factors regulating ex-Treg differentiation. Development of ex-Tregs was more efficient in the mesenteric lymph node (mLN) than peripheral lymph node environment, correlating with a much greater level of IL-6 mRNA in mLN. In addition, the preferential development of ex-Tregs in mLN was significantly impaired by cotransfer of HY-specific naive CD4 T cells. Collectively, our study not only demonstrates the plasticity of Ag-specific Tregs in the context of the tumor environment, but also defines key molecular and cellular events that modulate ex-Treg differentiation.  相似文献   
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