44 research outputs found
In vitro larvicidal activity of geraniol and citronellal against Contracaecum sp (Nematoda: Anisakidae)
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)
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
Potential parasitic infections transmitted by seafood in ancient populations from Patagonia
Several foodborne diseases have been described in coastal populations from the past, many of them including parasitic infections related to marine diets. Considering this background, the strong relationship between hunter-gatherers from Patagonia and the marine species implies a possible source of parasitic infections and zoonotic risk. However, marine parasitic species have not been identified in archaeological sites from Patagonia so far. The aim of this paper is to propose the potential parasitic infections produced by the consumption of marine molluscs, fishes, birds and sea mammals by human populations from Patagonia during the Holocene, considering the current parasitic species identified in the Southern Atlantic Ocean. We searched in journal articles and book chapters for references of archaeological remains of molluscs, fishes, seabirds and marine mammals recorded in archaeological sites from the Atlantic coast below the 42nd parallel South. Afterwards, we surveyed all the macroparasites of marine origin identified by current parasitological research in the same species found in the archaeological record. We found that most of the marine species in the zooarchaeological record of Patagonia are currently hosts of many parasites. Some species of molluscs, fishes and pinnipeds are highly infected by larvae that are potentially hazardous for human health. Some of them are responsible for acute or chronic zoonotic diseases, with severe consequences depending on how the food was cooked, the amount of consumed parasites and the immune response of the host, in this case, humans. Fishes are host of several parasites related to anisakidosis and corynosomiasis. Sea lions species were also a potential source of the same zoonosis but also diphyllobothriasis. Molluscs are hosts of several parasitic species, but with less severe consequences for human health. On the other hand, birds are infected by adult parasites, without direct zoonotic importance. These findings, although limited by temporal and environmental variability, can provide a speculative overview about the potential influence of marine diets in the health of past hunter-gatherers of Patagonia, particularly if fishes, molluscs or marine mammals were consumed inadequately cooked.Fil: Alarcos, Ana Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Suby, Jorge Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; Argentin