Search results for "Helium"
showing 10 items of 1689 documents
Chemistry of pheromonal and defensive secretions in the nymphs and the adults ofDysdercus cingulatus Fabr. (Heteroptera, Pyrrhocoridae)
1991
59 ref.; International audience; The exocrine secretions from the nymphs and the adults of both sexes in D. cingulatus were chemically investigated. Seven compounds were identified in the anterior glands, and eleven in the median dorsoabdominal glands of nymphs and adults of both sexes. Fifty-five compounds were identified in the defensive glands (34 in posterior dorsoabdominal glands ofnymphs and 21 in metathoracic glands of adults), and six in the sternal glandular epithelium of the males. The biological function of the glandular secretions and of their identified compounds were investigated and are discussed.
Hydrodynamics of the cocurrent downflow of a gas and a foaming liquid through a packed bed. Part I. Estimation of the transition boundary between the…
2004
Abstract In the study the results of investigations are presented aimed at determining such values of the operating parameters for which the change of the hydrodynamic regime occurs from the gas continuous flow (GCF) to the pulsing flow (PF). Nitrogen, helium and argon were used as the gas phase while the liquid phase was formed by the aqueous solutions of the alcohols C 1 –C 4 of the concentrations which ensured the foaming of the system. Thus a wide range of physicochemical properties of the system was covered in the experiments. The present study, as well as Part II, contain a wealth of experimental data which characterise the PF through the packing for the foam-forming systems. It is de…
Time-point and dosage of gene inactivation determine the tumor spectrum in conditional Ptch knockouts
2009
Mutations in Patched (PTCH) have been associated with tumors characteristic both for children [medulloblastoma (MB) and rhabdomyosarcoma (RMS)] and for elderly [basal cell carcinoma (BCC)]. The determinants of the variability in tumor onset and histology are unknown. We investigated the effects of the time-point and dosage of Ptch inactivation on tumor spectrum using conditional Ptch-knockout mice. Ptch heterozygosity induced prenatally resulted in the formation of RMS, which was accompanied by the silencing of the remaining wild-type Ptch allele. In contrast, RMS was observed neither after mono- nor biallelic postnatal deletion of Ptch. Postnatal biallelic deletion of Ptch led to BCC preca…
Endothelial Wnt/β-catenin signaling inhibits glioma angiogenesis and normalizes tumor blood vessels by inducing PDGF-B expression
2012
Wnt modulates glioma vascularization by regulating PDGF-B expression.
High Lymph Vessel Density and Expression of Lymphatic Growth Factors in Peritoneal Endometriosis
2012
To investigate the occurrence of lymph vessels and lymphangiogenic growth factors in peritoneal lesions, we performed immunohistochemical staining of peritoneal lesions of 37 patients with antibodies against podoplanin (D2-40), lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), prospero homeobox protein 1 (Prox-1), vascular epithelial growth factor (VEGF)-C/VEGF-D. Overall, 10 lesions were double stained against D2-40 and von Willebrand factor. The lymph vessel density in peritoneal lesion was significantly higher in comparison with healthy peritoneum. All lymph vessel makers could be detected, whereby the lymph vessel density of LYVE-1- and Prox-1-positive lymph vessels was signi…
C21orf2 is mutated in recessive early-onset retinal dystrophy with macular staphyloma and encodes a protein that localises to the photoreceptor prima…
2015
Background/aim We have noted a phenotype of early-onset retinal dystrophy with macular staphyloma but without high myopia. The aim of this study is to report the underlying genetic mutations and the subcellular localisation of the gene product in the retina. Methods Retrospective case series (2012–2015); immunohistochemical analyses of mammalian retina for in situ protein localisation. Results All three probands were first noted to have decreased vision at 3–6 years old which worsened over time. At ages 39, 37 and 12 years old, all had similar retinal findings: dystrophic changes (retinal pigment epithelium mottling, vessel narrowing), macular staphyloma (despite only mild myopia or high hy…
Ultrastructure of one Ewing's sarcoma of bone with endothelial character and a comparative review of the vessels in 27 cases of typical Ewing's sarco…
1980
An atypical variant of Ewing's sarcoma, located in the left hip of a nine-year-old girl, is discussed at optical, histochemical and electron microscopical level. The endothelial appearing cells seem to play a main role in its histogenesis. Tumoral cells of an undifferentiated blastemic nature show round nuclei and bright lucent cytoplasm, being organized in solid sheets or vascular-like profiles. Alkaline and acid phosphatases are very prominent in all tumoral cells, and some of them also show PAS positive material. Its ultrastructure demonstrates an active pinocytic capacity, cytoplasmic filaments and Weibel-Palade bodies. Simultaneously a review is performed on 27 cases of typical Ewing's…
Confocal laser endomicroscopy for the diagnosis of urothelial bladder neoplasia: a technology of the future?
2010
Study Type – Diagnostic (exploratory cohort) Level of Evidence 2b What’s known on the subject? and What does the study add? Bladder cancer is initially diagnosed by white light cystoscopy followed by histopathological evaluation after transurethral resection of tissue suspicious for cancer. Difficulties may occur especially in the assessment of flat lesions or in discrimination between CIS and inflammatory disease. Confocal endomicroscopy during diagnostic colonoscopy has been a valuable tool for in vivo microscopic visualization and detection of colonic neoplasias and has contributed to optimized detection rates of up to 99%. We evaluated resected bladder urothelium of 18 patients by confo…
Extracellular calcium-sensing receptor mediates human bronchial epithelial wound repair
2010
The airway epithelium routinely undergoes damage that requires repair to restore epithelial barrier integrity. Cell migration followed by proliferation are necessary steps to achieve epithelial repair. Calcium-sensing receptor (CaSR) is implicated in cell migration and proliferation processes. Thus we hypothesized that CaSR mediates lung epithelial wound repair. We detected CaSR expression in human lung and in well-differentiated human bronchial epithelial cells (HBEC). To test the CaSR functionality, HBEC loaded with fura-2 were stimulated with extracellular Ca(2+) ([Ca(2+)](out)) which resulted in a concentration-dependent intracellular Ca(2+) ([Ca(2+)](i)) increase (potency approximately…
Central Odontogenic Fibroma combined with Central Giant Cell lesion of the mandible. Immunohistochemical profile.
2011
Central Odontogenic Fibroma is a benign neoplasm of mesenchymal origin that makes up less than 5% of odontogenic tumors. There is a variation of this lesion that includes a zone of giant cells. This neoplasm is characterized by fibroblast proliferation, a component of apparently inactive odontogenic epithelium within a mature connective tissue stroma and multinucleated osteoclast-like giant cells. Clinically, it manifests as a slow-growing central lesion, which causes painless cortical expansion and may occasionally cause the displacement of adjacent dental organs or resorption. We present a new case of this combined lesion that was revealed radiographically as a well-defined radiolucent ar…