48 research outputs found
In vitro larvicidal activity of geraniol and citronellal against Contracaecum sp (Nematoda: Anisakidae)
Acoustophoresis of disk-shaped microparticles: A numerical and experimental study of acoustic radiation forces and torques
Contracaecumovale (Nematoda: Anisakidae) from Rollandia rolland Quoy & Gaimard 1824 (Aves, Podicipedidae) in Argentina Contracaecumovale (Nematoda: Anisakidae) de Rollandia rolland Quoy & Gaimard 1824 (Aves, Podicipedidae) na Argentina
Necropsy on 15 specimens of white-tufted grebe, Rollandiarolland, caught in the Mar Chiquita and Chascomús lagoons (Buenos Aires province), revealed the presence of Contracaecumovale (Linstow, 1907). This nematode shows a marked specificity for podicipediform birds. The specimens were identified from morphological study on features such as cephalic and esophageal structures and caudal papillae, using both optical and scanning electron microscopy. This is the first record of C. ovale parasitizing R. rolland in Argentina.<br>Necropsia de 15 espécimes de mergulhão-de-orelha-branca, Rollandiarolland, coletados nas lagoas Mar Chiquita e Chascomús (Província de Buenos Aires), revelou a presença de Contracaecumovale (Linstow, 1907). Esse nematóide tem uma marcada especificidade pelas aves podicipediformes. Os espécimes foram identificados a partir de características, tais como estruturas morfológicas cefálicas e esofágicas e papilas caudais, utilizando-se microscopia óptica e microscopia eletrônica de varredura (MEV). Esse é o primeiro registro de C. ovale parasito de R. rolland na Argentina
Improved Swiss-rolling method for histological analyses of colon tissue
: Since the introduction of the Swiss-rolling technique by Reilly and Kirsner in 1965, various methodological approaches have been developed for histological analyses of intestinal tissues. Here, we describe an improved protocol for the processing of freshly harvested murine colons that can be extended to other intestinal tissues. With simple tools, this technique allows to tightly wrap the organ throughout the whole length and to keep it in place before fixation, avoiding excessive stiffness of the tissue. Unlike the original method which relies on frozen samples, processing of the biological samples right after resection preserves epitopes integrity for subsequent immunohistochemical analyses. Ultimately, this method provides a reproducible workflow to capture the entire colon length in a unique histological section in order to assess several features such as intestinal inflammation and tumorigenesis. • Easily include freshly isolated tissues • Shorten preparation time using a few affordable tools • Prevent unrolling and preserve tissue integrity
Two-photon absorption properties of Zn(II) complexes: Unexpected large TPA cross section of dipolar [ZnY2(4,4′-bis(para-di-n-butylaminostyryl)-2,2′-bipyridine)] (Y=Cl, CF3CO2)
Two-photon absorption properties of Zn(II) complexes: Unexpected large TPA cross section of dipolar [ZnY2(4,4 '-bis(para-di-n-butylaminostyryl)-2,2 '-bipyridine)] (Y = Cl, CF3CO2)
The two-photon absorption (TPA) properties of 4,4'-bis(para-di-n-butylaminostyryl)-2,2'-bipyridine (NBu(2)bipy) and related dipolar ([ZnY(2)(NBu(2)bipy)] (Y = Cl, CF(3)CO(2)), [Zn(2,2'-bipyridine) (2)(NBu(2)bipy)][PF(6)](2)) and octupolar ([Zn(NBu(2)bipy)(3)][PF(6)](2)) complexes were investigated by the two-photon emission (TPE) technique in a femtosecond regime, working in the 730-930 nm spectral range. We found, in contrast with previous literature data, that the TPA enhancement upon coordination of a TPA active ligand to a metal center may be larger in the dipolar rather than the corresponding octupolar complex, the response being easily modulated by the choice of the ancillary ligands
Lipid-rich diet enhances L-cell density in obese subjects and in mice through improved L-cell differentiation
International audienceThe enterohormone glucagon-like peptide-1 (GLP-1) is required to amplify glucose-induced insulin secretion that facilitates peripheral glucose utilisation. Alteration in GLP-1 secretion during obesity has been reported but is still controversial. Due to the high adaptability of intestinal cells to environmental changes, we hypothesised that the density of GLP-1-producing cells could be modified by nutritional factors to prevent the deterioration of metabolic condition in obesity. We quantified L-cell density in jejunum samples collected during Roux-en-Y gastric bypass in forty-nine severely obese subjects analysed according to their fat consumption. In mice, we deciphered the mechanisms by which a high-fat diet (HFD) makes an impact on enteroendocrine cell density and function. L-cell density in the jejunum was higher in obese subjects consuming > 30 % fat compared with low fat eaters. Mice fed a HFD for 8 weeks displayed an increase in GLP-1-positive cells in the jejunum and colon accordingly to GLP-1 secretion. The regulation by the HFD appears specific to GLP-1-producing cells, as the number of PYY (peptide YY)-positive cells remained unchanged. Moreover, genetically obese ob/ob mice did not show alteration of GLP-1-positive cell density in the jejunum or colon, suggesting that obesity per se is not sufficient to trigger the mechanism. The higher L-cell density in HFD-fed mice involved a rise in L-cell terminal differentiation as witnessed by the increased expression of transcription factors downstream of neurogenin3 (Ngn3). We suggest that the observed increase in GLP-1-positive cell density triggered by high fat consumption in humans and mice might favour insulin secretion and therefore constitute an adaptive response of the intestine to balance diet-induced insulin resistance
Expression and modulation of the Lewis x antigen (CD15) on the T cell line Molt-4
AbstractThe T cell lines Molt-4 and H9 exhibited a characteristic distribution of the cell adhesion molecule Lewis x (CD15, lacto-N-fucopentanose III) showing an unusually broad peak by flow cytometry ranging from cells without CD15 to cells with high expression. The cytokines IL-1, IL-2, IFN-β, IFN-γ, and TNF-α, known to activate T cells, did not affect CD15 expression. However, phorbol myristate acetate and the thymic peptide extract Thymex-L were able to enhance both the number of CD15-positive cells and the median fluorescence. The effects of both inducers were dose- and time-dependent. An additive or synergistic effect was not seen. These data suggest that phorbol esters and distinct thymic peptides can modulate the expression of the cell surface antigen CD15
