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51.
Immunostimulatory sequence (ISS) DNA containing unmethylated CpG dinucleotides stimulate NK and APC to secrete proinflammatory cytokines, including IFN-alphabeta and -gamma, TNF-alpha, and IL-6 and -12, and to express costimulatory surface molecules such as CD40, B7-1, and B7-2. Although ISS DNA has little direct effect on T cells by these criteria, immunization of wild-type mice with ISS DNA and OVA results in Ag-specific CTL and Th1-type T helper activity. This investigation examines the mechanisms by which ISS DNA primes CD8(+) and CD4(+) lymphocyte activities. In this report we demonstrate that ISS DNA regulates the expression of costimulatory molecules and TAP via a novel autocrine or paracrine IFN-alphabeta pathway. Coordinated regulation of B7 costimulation and TAP-dependent cross-presentation results in priming of Ag-specific CD8(+) CTL, whereas CD40, B7, and IL-12 costimulation is required for priming of CD4(+) Th cells by ISS-based vaccines.  相似文献   
52.
The infection status with Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fishes from Yongjeon-cheon (a branch of Nakdong-gang) located in Cheongsong-gun, Gyeongsangbuk-do, the Republic of Korea (Korea). A total of 750 fishes in 19 species were examined by the artificial digestion method for 2 years (2019 and 2020). CsMc were detected in 378 (51.4%) out of 735 fishes in 14 species (73.7%), and the infection intensity was 666 per fish infected. In 2019, CsMc were found in 172 (68.0%) out of 253 fishes in 10 species, and the infection intensity was 565 per fish infected. In 2020, CsMc were detected in 206 (62.2%) out of 331 fishes in 10 species, and the infection intensity was 751 per fish infected. The other zoonotic trematode, ie. Metagonimus spp., Centrocestus armatus, Echinostoma spp. and Clinostomum complanatum, metacercariae were also detected in fishes from the survey streams, but their endemicities were relatively low. Conclusively, it was first confirmed that CsMc are highly endemic in fishes from Yongjeon-cheon in Cheongsong-gun, Gyeongsangbuk-do, Korea.  相似文献   
53.
The present study investigated characteristics of 24 parasite infection cases detected during colonoscopy in a regional hospital from January 2001 to December 2008. Sixteen patients were confirmed with Trichuris trichiura infection, 6 patients were with Ascaris lumbricoides infection, 1 patient with Enterobius vermicularis infection, and 1 patient with Anisakis infection. Among them, 7 patients (43.8%) were asymptomatic. Colonoscopy findings were normal in 18 patients (75.0%). Among the patients with T. trichiura infection, colonoscopy showed several erosions in 2 patients (8.3%) and non-specific inflammation of the affected segment of the colon in 3 patients (12.5%). In 1 patient with anisakiasis, colonoscopy revealed a markedly swollen colonic wall. Stool examinations were performed before treatment in 7 patients (29.2%) and were all negative for parasite eggs or worms. These results suggest that colonoscopy is a useful diagnostic approach for parasitic infections even for asymptomatic patients and for patients with negative stool examinations.  相似文献   
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Precise DNA manipulation is critical for molecular biotechnology. Restriction enzyme-based approaches are limited by their requirement of specific enzyme sites. Restriction-free cloning has greatly improved the flexibility and speed of precise DNA assembly. Most of these approaches focus on DNA assembly rather than gene removal. Here we present a polymerase chain reaction (PCR)-based cloning method that allows removal of multiple gene segments from plasmids without using restriction enzymes and thermostable ligase. We demonstrate simultaneous removal of three gene segments from a plasmid. This approach could be beneficial to DNA library construction, genetic and protein engineering, and synthetic biology.  相似文献   
56.
In the course of our search for bioactive metabolites from a colonial tunicate of the family Polyclinidae, six new (16) cyclic fatty acid derivatives were isolated. Their planar structures were established on the basis of NMR and MS spectroscopic analyses. The relative configuration was determined by NOESY experiment. Compounds 16 represent a fused bicyclic skeleton possibly derived from α,ω-dicarboxylic acids such as eicosanedioic acid or docosanedioic acid via a Diels–Alder type of cyclization. Compounds 14 and 6 showed mild cytotoxicity against a panel of five human solid tumor cell lines.  相似文献   
57.
The purpose of this investigation was to characterize the in vitro stability and in vivo disposition of paclitaxel in rats after solubilization of paclitaxel into hydrotropic polymeric micelles. The amphiphilic block copolymers consisted of a micellar shell-forming poly(ethylene glycol) (PEG) block and a core-forming poly(2-(4-vinylbenzyloxy)-N,N-diethylnicotinamide) (P(VBODENA)) block. N,N-Diethylnicotinamide (DENA) in the micellar inner core resulted in effective paclitaxel solubilization and stabilization. Solubilization of paclitaxel using polymeric micelles of poly(ethylene glycol)-b-P(D,L-lactide) (PEG-b-PLA) served as a control for the stability study. Up to 37.4 wt % paclitaxel could be loaded in PEG-b-P(VBODENA) micelles, whereas the maximum loading amount for PEG-b-PLA micelles was 27.6 wt %. Thermal analysis showed that paclitaxel in the polymeric micelles existed in the molecularly dispersed amorphous state even at loadings over 30 wt %. Paclitaxel-loaded hydrotropic polymeric micelles retained their stability in water for weeks, whereas paclitaxel-loaded PEG-b-PLA micelles precipitated in a few days. Hydrotropic polymer micelles were more effective than PEG-PLA micelle formulations in inhibiting the proliferation of human cancer cells. Paclitaxel in hydrotropic polymer micelles was administered orally (3.8 mg/kg), intravenously (2.5 mg/kg), or via the portal vein (2.5 mg/kg) to rats. The oral bioavailability was 12.4% of the intravenous administration. Our data suggest that polymeric micelles with a hydrotropic structure are superior as a carrier of paclitaxel due to a high solubilizing capacity combined with long-term stability, which has not been accomplished by other existing polymeric micelle systems.  相似文献   
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59.
Acetohydroxy acid isomeroreductase (AHIR) is a key enzyme in the biosynthesis of branched-chain amino acids. We have determined the first crystal structure of a class I AHIR from Pseudomonas aeruginosa at 2.0 A resolution. Its dodecameric architecture of 23 point group symmetry is assembled of six dimeric units and dimerization is essential for the formation of the active site. The dimeric unit of P.aeruginosa AHIR partially superimposes with a three-domain monomer of spinach AHIR, a class II enzyme. This demonstrates that the so-called plant-specific insert in the middle of spinach AHIR is structurally and functionally equivalent to the C-terminal alpha-helical domain of P.aeruginosa AHIR, and the C-terminal alpha-helical domain was duplicated during evolution from the shorter, class I AHIRs to the longer, class II AHIRs. The dimeric unit of P.aeruginosa AHIR possesses a deep figure-of-eight knot, essentially identical with that in the spinach AHIR monomer. Thus, our work lowers the likelihood of the previous proposal that "domain duplication followed by exchange of a secondary structure element can be a source of such a knot in the protein structure" being correct.  相似文献   
60.
The relationship between ultradian rhythm of heart rate and schedules of body contact or feeding was studied in five low birth weight infants of conceptional ages of 34-36 weeks. The differential contribution of body contact and feeding to the formation of the ultradian rhythm of heart rate was evaluated by applying two different schedules of two- and three-hour periods for feeding with a single schedule of three hours for body contact during an observation period of seven days. A chi-square periodogram was used to calculate the period of ultradian rhythm. As a result, a three-hour ultradian rhythm of heart rates was detected in all subjects, which seems to correspond to either schedule of body contact or of feeding. However, no clear changes in the ultradia n rhythm of heart rate were observed corresponding to changes in feeding schedules. The ultradian rhythm of heart rate seems to correspond more to body contact than to feeding.  相似文献   
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