799 research outputs found

    Conservation of Silk Genes in Trichoptera and Lepidoptera

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    Larvae of the sister orders Trichoptera and Lepidoptera are characterized by silk secretion from a pair of labial glands. In both orders the silk filament consists of heavy (H)- and light (L)-chain fibroins and in Lepidoptera it also includes a P25 glycoprotein. The L-fibroin and H-fibroin genes of Rhyacophila obliterata and Hydropsyche angustipennis caddisflies have exon/intron structuring (seven exons in L-fibroin and two in H-fibroin) similar to that in their counterparts in Lepidoptera. Fibroin cDNAs are also known in Limnephilus decipiens, representing the third caddisfly suborder. Amino acid sequences of deduced L-fibroin proteins and of the terminal H-fibroin regions are about 50% identical among the three caddisfly species but their similarity to lepidopteran fibroins is <25%. Positions of some residues are conserved, including cysteines that were shown to link the L-fibroin and H-fibroin by a disulfide bridge in Lepidoptera. The long internal part of H-fibroins is composed of short motifs arranged in species-specific repeats. They are extremely uniform in R. obliterata. Motifs (SX)n, GGX, and GPGXX occur in both Trichoptera and Lepidoptera. The trichopteran H-fibroins further contain charged amphiphilic motifs but lack the strings of alanines or alanine-glycine dipeptides that are typical lepidopteran motifs. On the other hand, sequences composed of a motif similar to ERIVAPTVITR surrounded by the (SX)4-6 strings and modifications of the GRRGWGRRG motif occur in Trichoptera and not in Lepidoptera

    Broad ligament cystic lymphangioma: A case report

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

    Kinetic Force Method with Quasiparticle Pairs for Numerical Modeling 3D Rarefied Gas Flows

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    Abstract. In the paper a new way of Kinetic Force Method application for modeling rarefied gas flows is suggested. This way is founded on a kinetic equation for auxiliary two-particle distribution function of quasiparticle pairs. One-particle distribution function satisfying the classical Boltzmann equation can be obtained from the auxiliary distribution function by a simple integration. The using of quasiparticle pairs guarantees energy and momentum conservation in the course of the rarefied gas flows modeling automatically. Comparison of the results obtained by Kinetic Force Method and DSMC method is carried out on the examples of numerical simulations of the homogeneous relaxation and the vacuum pump micro flows

    Different significance between intratumoral and peritumoral lymphatic vessel density in gastric cancer: a retrospective study of 123 cases

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    <p>Abstract</p> <p>Background</p> <p>Patients with gastric cancer in China have worse outcome and poorer prognosis. Tumor-induced lymphangiogenesis plays a crucial role in metastasis and tumor progression. The intratumoral and peritumoral lymphatics were supposed to have different biological effects. Three major growth factors, vascular endothelial growth factor- (VEGF)-A, VEGF-C and VEGF-D, are involved in the activation process via their receptors (VEGFRs). The purpose of current study is to investigate the significant difference between intratumoral and peritumoral lymphatic vessel density (LVD) in gastric cancer and their correlations with lymphangiogenetic growth factors.</p> <p>Methods</p> <p>Intratumoral LVD (I-LVD) and peritumoral LVD (P-LVD) of 123 patients with primary gastric cancer were assessed after staining with D2-40, and confirmed by double staining with D2-40/CD34. Proliferative activity of lymphatics endothelium was evaluated by double staining with D2-40/Ki-67. The associations were analyzed between I-LVD/P-LVD and the expression level of VEGF-A, VEGF-C, VEGF-D and the receptor VEGFR-3, which was measured by immunohistochemistry (IHC). The correlations of I-LVD and P-LVD with patient prognosis were also valued.</p> <p>Results</p> <p>(1) The peritumoral lymphatics (PTLs) were relatively enlarged with dilated lumen compared with the intratumoral lymphatics (ITLs). Increased P-LVD was significantly higher than I-LVD (<it>P </it>< 0.05). (2) P-LVD was found significantly associated with lymph node metastasis (LNM) (<it>P </it>< 0.001), lymphatic vessel invasion (LVI) (<it>P </it>< 0.001), VEGF-C (<it>P </it>= 0.003), VEGF-D expression level (<it>P </it>= 0.005) and VEGFR-3 expression level (<it>P </it>< 0.001) in peritumoral tissues, despite no significant association was found between above variants with I-LVD. However, increased I-LVD was demonstrated to be associated with decreased tumor volume (<it>P </it>< 0.001). Neither I-LVD nor P-LVD was correlated with VEGF-A expression (<it>P </it>> 0.05). (3) Proliferative activity of lymphatics endothelium was observed in PTLs, in spite of ITLs. (4) Increased P-LVD, but not I-LVD, was indicated to be an independent risk factor for lymph node metastasis by multivariate logistic regression analysis, and was related to worse disease-free survival and overall survival.</p> <p>Conclusions</p> <p>PTLs play roles in gastric cancer progression. Increased P-LVD, but not I-LVD, was significantly associated with VEGF-C/-D/VEGFR-3 system, and could be an independent risk factor for lymph node metastasis and a prognostic factor in gastric cancer.</p
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