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11.
After re-emergence of malaria in 1993, a continued increase in Plasmodium vivax cases was observed from 1993 to 2006 in northern Gyeonggi and Gangwon Provinces adjacent to the demilitarized zone separating North from South Korea. Annual parasite incidence per 1000 people ranged from 0.33 in 2004 to 0.89 in 2006. While malaria case rates declined (22.6%) in 2004, they increased 75.1% in 2005 and 51.7% in 2006 from the previous years. An initial incorrect diagnosis of 46.8% of malaria cases as common cold resulted in a mean delay of 1.3 days for the detection malarial parasites. Of the total cases, 10.2% from December to May were due to latent intrinsic incubation infections acquired the previous malaria season and the rest of the cases from June to November were either latent or short incubation infections. Overall, the peak anopheline population occurred from July to September, resulting in a similar peak in malaria cases. While malaria cases increased during 2005–2006, anopheline populations, based on trap indices, were not significantly different during 4 years of surveillance. To decrease the malaria patient infective period to mosquitoes, public health centers in Paju and Cheorwon in 2006 prescribed chloroquine + primaquine at days 0–3 after initial malaria diagnosis followed by an additional 11 days of primaquine (early primaquine treatment), rather than chloroquine on days 0–3 and primaquine on days 4–17 (delayed primaquine treatment). A reduction in the malaria parasite incidence during 2007 was recorded for the two locations offering the early primaquine treatment relative to other locations using the delayed primaquine treatment.  相似文献   
12.
During early vertebrate development, neural crest cells emerge from the dorsal neural tube, migrate into the periphery, and form a wide range of derivatives. There is, however, a significant difference between the cranial and trunk neural crest with respect to the diversity of cell types that each normally produces. Thus, while crest cells from all axial levels form neurons, glia, and melanocytes, the cranial crest additionally generates skeletal derivatives such as bone and cartilage; trunk crest cells are generally thought to lack skeletogenic potential. Here, we show, however, that if avian trunk neural crest cells are cultured in appropriate media, they form both bone and cartilage cells, and if placed into the developing head, they contribute to cranial skeletal components. Thus, the neural crest from all axial levels can generate the full repertoire of crest derivatives. The skeletogenic potential of the trunk neural crest is significant, as it was likely realized in early vertebrates, which had extensive postcranial exoskeletal coverings.  相似文献   
13.
Summary The possible role of extracellular calcium ([Ca+2]e) in cryopreservation-induced cytotoxicity was tested using Madin-Darby canine kidney (MDCK) cells and a fluorescent multiple endpoint assay. MDCK cells maintained in 2 mM [Ca+2]e and treated with the calcium ionophore, ionomycin, increased their intracellular calcium ([Ca+2]i) as revealed by the calcium indicator dye, Fluo3 and the bottom-reading spectrofluorometer, CytoFluor 2300. The addition of 10 mM [ethylene bis (oxyethylenenitrilo)]-tetraacetic acid (EGTA) to the extracellular medium before treatment with ionomycin blocked this ionomycin-dependent increase in [Ca+2]i. A number of site and activity-specific fluorescent probes were surveyed to determine which indicator dye might best reveal the ionomycin-induced cytotoxic events during this increase in [Ca+2]i. Although most dyes changed their emission profiles in response to calcium, neutral red was found to best reflect the loss of [Ca+2]i homeostasis. The NR50 for a 15-min exposure to ionomycin in the presence of 2 mM [Ca+2]e was approximately 2μM ionomycin, but ionomycin had little apparent effect on neutral red retention when 10 mM EGTA was added to the extracellular medium. Thus it was clear that an increase in [Ca+2]i could be cytotoxic to MDCK cells and that neutral red could monitor this cytotoxic episode. To test if [Ca+2]e was similarly cytotoxic during cryopreservation, MDCK cells were subjected to cryopreservation in the presence of dimethylsulfoxide (DMSO). In contrast to previous studies, plasma membrane integrity, not lysosomal function, seemed to best correlate with cell survival subsequent to cryopreservation. In addition, decreasing [Ca+2]e had no discernable effect on the retention of plasma membrane indicator dyes, neutral red, or cell survival. It is concluded that a) plasma membrane indicator dyes, not neutral red, might be better indicators of cytotoxicity occurring during cryopreservation; b) DMSO might be toxic to lysosomes during cryopreservation of cultured cells; and c) although [Ca+2]e can contribute to cytotoxicity, the presence of [Ca+2]e might not influence cryopreservation-induced cytotoxicity.  相似文献   
14.

Background  

The analysis of microarray experiments requires accurate and up-to-date functional annotation of the microarray reporters to optimize the interpretation of the biological processes involved. Pathway visualization tools are used to connect gene expression data with existing biological pathways by using specific database identifiers that link reporters with elements in the pathways.  相似文献   
15.
We have identified a novel N -acetylgalactosaminyltransferase activity in lactating bovine mammary gland membranes. Acceptor specificity studies and analysis of products obtained in vitro by 400 MHz1H-NMR spectroscopy revealed that the enzyme catalyses the transfer of N - acetylgalactosamine (GalNAc) from UDP-GalNAc to acceptor substrates carrying a terminal, beta-linked N -acetylglucosamine (GlcNAc) residue and establishes a beta1-->4-linkage forming a GalNAcbeta1-->4GlcNAc ( N, N '-diacetyllactosediamine, lacdiNAc) unit. Therefore, the enzyme can be identified as a UDP-GalNAc:GlcNAcbeta-R beta1-->4-N- acetylgalactosaminyltransferase (beta4-GalNAcT). This enzyme resembles invertebrate beta4-GalNAcT as well as mammalian beta4- galactosyltransferase (beta4-GalT) in acceptor specificity. It can, however, be clearly distinguished from the pituitary hormone-specific beta4-GalNAcT by its incapability of acting with an elevated activity on a glycoprotein substrate carrying a hormone-specific peptide motif. Furthermore, the GalNAcT activity appeared not to be due to a promiscuous action of a beta4-GalT as could be demonstrated by comparing the beta4-GalNAcT and beta4-GalT activities of the mammary gland, bovine colostrum, and purified beta4-GalT, by competition studies with UDP-GalNAc and UDP-Gal, and by use of an anti-beta4-GalT polyclonal inhibiting antibody. Interestingly, under conditions where mammalian beta4-GalT forms with alpha-lactalbumin (alpha-LA) the lactose synthase complex, the mammary gland beta4-GalNAcT was similarly induced by alpha-LA to act on Glc with an increased efficiency yielding the lactose analog GalNAcbeta1-->4Glc. This enzyme thus forms the second example of a mammalian glycosyltransferase the specificity of which can be modified by this milk protein. It is proposed that the mammary gland beta4-GalNAcT functions in the synthesis of lacdiNAc- based, complex-type glycans frequently occurring on bovine milk glycoproteins. The action of this enzyme is to be considered when aiming at the production of properly glycosylated protein biopharmaceuticals in the milk of transgenic dairy animals.   相似文献   
16.
The phylum Porifera (sponges) was the first to diverge from the common ancestor of the Metazoa. In this study, six cDNAs coding for protein- serine/threonine kinases (PS/TKs) are presented; they have been isolated from libraries obtained from the demosponges Geodia cydonium and Suberites domuncula and from the calcareous sponge Sycon raphanus. Sequence alignments of the catalytic domains revealed that two major families of PS/TK, the "conventional" (Ca(2+)-dependent) protein kinase C (PKC), the cPKC subfamily, as well as the "novel" (Ca(2+)- independent) PKC (nPKC), form two separate clusters. In each cluster, the sequence from S. raphanus diverges first. To approach the question about the origin of protein-tyrosine kinases (PTK), which are found only in Metazoa, we analyzed two additional PS/TKs which have been cloned from S. domuncula: the stress-responsive protein kinase (KRSvSD) and the protein-kinase-C-related kinase (PRKvSD). The construction of the phylogenetic tree, comprising the eight PS/TKs and the PTK cloned previously from G. cydonium, revealed that the PTK derived from the branch including the KRSvSD kinase. These data facilitate the first molecular approach to elucidate the origin of metazoan PTK within the PS/TK superfamily.   相似文献   
17.
Electron microscopy of ultrathin sections of leaves of symptomless Himalaya Giant blackberry and of the virus indicator species, Rubus macraei, showing severe leaf curl symptoms following graft inoculation with scions from this blackberry, detected highly flexuous virus‐like particles with an unusual ‘beaded’ structure. Such particles were restricted to a few vascular cells and were distinct from P‐protein common in some such cells. This virus, provisionally named Hawaiian rubus leaf curl virus (HRLCV), symptomlessly infected a wide range of Rubus species and cultivars. Badnavirus‐like bacilliform particles were observed in some cells of a single R. macraei plant showing leaf curl symptoms following graft inoculation with the causal agent of this disease symptom from Himalaya Giant blackberry after passage through red raspberry, but not in any other material. PCR with primer sets for the badnaviruses Rubus yellow net virus and Gooseberry veinbanding associated virus, showed that no Rubus sources studied contained these viruses. However, using a sequence‐specific primer set designed from the sequence of the product generated with a badnavirus degenerate primer set, a specific product was amplified from healthy plants of all of 16 raspberry cultivars and two Rubus species, but not from 16 blackberry cultivars (including cv. Himalaya Giant). All of these sources were free from viruses known to occur in Rubus. Sequence analysis of this product showed no homology with any known badnavirus, or with any other published sequences. It seems most likely therefore that a region of the raspberry genome has been amplified using the degenerate badnavirus primer set and that it is absent from the blackberry genome.  相似文献   
18.
The bone morphogenetic proteins (BMPs) are a family of the transforming growth factor- (TGF-) superfamily that perform multiple roles during vertebrate and invertebrate development. Here, we report the molecular cloning of a novel BMP from regenerating arms of the ophiuroid Amphiura filiformis. The theoretically translated amino acid sequence of this novel BMP has high similarity to that of the sea urchin BMP univin. This novel BMP has been named afuni. Whole-mount in situ hybridisation implicates afuni in arm regeneration. Expression occurs in distinct proximal and distal regions of late regenerates (3- and 5-week postablation). These sites are at different stages of regeneration, suggesting multiple roles for this gene in adult arm development. Cellular expression of this gene occurs in migratory cells within the radial water canal (RWC) of regenerating and nonregenerating arms. These migrating coelomocytes suggest a key role for the coelomic RWC as a source of the cellular material for use in arm regeneration by A. filiformis.  相似文献   
19.
Spinal motor neurons must extend their axons into the periphery through motor exit points (MEPs), but their cell bodies remain within spinal motor columns. It is not known how this partitioning is established in development. We show here that motor neuron somata are confined to the CNS by interactions with a neural crest subpopulation, boundary cap (BC) cells that prefigure the sites of spinal MEPs. Elimination of BC cells by surgical or targeted genetic ablation does not perturb motor axon outgrowth but results in motor neuron somata migrating out of the spinal cord by translocating along their axons. Heterologous neural crest grafts in crest-ablated embryos stop motor neuron emigration. Thus, before the formation of a mature transitional zone at the MEP, BC cells maintain a cell-tight boundary that allows motor axons to cross but blocks neuron migration.  相似文献   
20.
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