1,216 research outputs found

    Social biology of Liostenogaster vechti Turillazzi 1988 (Hymenoptera Stenogastrinae)

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    Liostenogaster vechti Turillazzi 1988, studied in Peninsular Malaysia, nests in huge aggregation of colonies, building its ring- or bracket-shaped nests on protected, smooth surfaces under overhanging rocks, bridge vaults etc. The biology and social behaviour of this species presents all the characteristics which set the Stenogastrinae aside from the other social vespids, i.e. production of an abdominal substance to help rear the immature brood, a three phase egg deposition, the presence of only four larval instars and the establishment of invariably small sized colonies. Colony life revolves round a dominant female, which has developed ovaries and spends most of her time on the nest. Colonies belonging to clusters from two separate localities showed a different percentages of potential egg layers per nest. In one cluster in particular, most of the colonies had only one egg layer, in spite of the differences in female population size. Like L. flavolineata (Cameron 1902), the colonial size of L. vecthi see..

    The meaning of different forms of structural myocardial injury, immune response and timing of infarct necrosis and cardiac repair

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    Although a decline in the all-cause and cardiac mortality rates following myocardial infarction (MI) during the past 3 decades has been reported, MI is a major cause of death and disability worldwide. From a pathological point of view MI consists in a particular myocardial cell death due to prolonged ischemia. After the onset of myocardial ischemia, cell death is not immediate, but takes a finite period of time to develop. Once complete myocytes’ necrosis has occurred, a process leading to a healed infarction takes place. In fact, MI is a dynamic process that begins with the transition from reversible to irreversible ischemic injury and culminates in the replacement of dead myocardium by a fibrous scar. The pathobiological mechanisms underlying this process are very complex, involving an inflammatory response by several pathways, and pose a major challenge to ability to improve our knowledge. An improved understanding of the pathobiology of cardiac repair after MI and further studies of its underlying mechanisms provide avenues for the development of future strategies directed toward the identification of novel therapies. The chronologic dating of MI is of great importance both to clinical and forensic investigation, that is, the ability to create a theoretical timeline upon which either clinicians or forensic pathologists may increase their ability to estimate the time of MI. Aging of MI has very important practical implications in clinical practice since, based on the chronological dating of MI, attractive alternatives to solve therapeutic strategies in the various phases of MI are developing

    The morphology of Van der Vecth's organ as a tool to measure caste dimorphism in Polistes paper wasps: a comparative approach

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    Given the centrality of chemical communication in social insects, there are many selective pressures acting on morpho-functional traits that mediate chemical pheromones. On the last gastral sternite of Polistes females, there is an important exocrine surface secreting chemical pheromone, named Van der Vecht's organ. It is involved in chemical defence of the nest, in rank and nestmate recognition, preventing workers from direct reproduction. Allometric differential growth of phenotypic traits between castes of social insects is generally considered as an indication of incipient physical castes. European Polistes present different nesting strategies and reproductive choices. Here, we carry out a comparison of Van der Vecht's organ size between castes of four European Polistes to provide a general measure of dimorphism. We show that Van der Vecht's organ of Polistes dominula and Polistes nimphus foundresses shows an allometric development being enlarged with respect to workers. Otherwise, no allometries have been highlighted in the other two studied species (i.e. Polistes associus and Polistes biglumis). Therefore, our data show that neither rigid monogyny nor specific nesting habits foster the evolution of true morphological castes in primitively eusocial taxa. Thus, at least two other species of Ezuropean Polistes show real evidence of incipient morphological castes

    Donor selection for allogenic hemopoietic stem cell transplantation: clinical and ethical considerations

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    Allogenic hematopoietic progenitor cell transplantation (allo-HSCT) is an established treatment for many diseases. Stem cells may be obtained from different sources: mobilized peripheral blood stem cells, bone marrow, and umbilical cord blood. The progress in transplantation procedures, the establishment of experienced transplant centres, and the creation of unrelated adult donor registries and cord blood banks gave those without an human leucocyte antigen- (HLA-) identical sibling donor the opportunity to find a donor and cord blood units worldwide. HSCT imposes operative cautions so that the entire donation/transplantation procedure is safe for both donors and recipients; it carries with it significant clinical, moral, and ethical concerns, mostly when donors are minors. The following points have been stressed: the donation should be excluded when excessive risks for the donor are reasonable, donors must receive an accurate information regarding eventual adverse events and health burden for the donors themselves, a valid consent is required, and the recipient’s risks must be outweighed by the expected benefits. The issue of conflict of interest, when the same physician has the responsibility for both donor selection and recipient care, is highlighted as well as the need of an adequate insurance protection for all the parties involved

    Cardiac oxidative stress and inflammatory cytokines response after myocardial infarction

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    Oxidative stress in heart failure or during ischemia/reperfusion occurs as a result of the excessive generation or accumulation of free radicals or their oxidation products. Free radicals formed during oxidative stress can initiate lipid peroxidation, oxidize proteins to inactive states and cause DNA strand breaks. Oxidative stress is a condition in which oxidant metabolites exert toxic effects because of their increased production or an altered cellular mechanism of protection. In the early phase of acute heart ischemia cytokines have the feature to be functional pleiotropy and redundancy, moreover, several cytokines exert similar and overlapping actions on the same cell type and one cytokine shows a wide range of biological effects on various cell types. Activation of cytokine cascades in the infarcted myocardium was established in numerous studies. In experimental models of myocardial infarction, induction and release of the pro-inflammatory cytokines like TNF-&alpha (Tumor Necrosis Factor &alpha), IL-1&beta (Interleukin- 1&beta) and IL-6 (Interleukin-6) and chemokines are steadily described. The current review examines the role of oxidative stress and pro-inflammatory cytokines response following acute myocardial infarction and explores the inflammatory mechanisms of cardiac injur

    Confocal laser scanning microscope, raman microscopy and western blotting to evaluate inflammatory response after myocardial infarction

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    Cardiac muscle necrosis is associated with inflammatory cascade that clears the infarct from dead cells and matrix debris, and then replaces the damaged tissue with scar, through three overlapping phases: the inflammatory phase, the proliferative phase and the maturation phase. Western blotting, laser confocal microscopy, Raman microscopy are valuable tools for studying the inflammatory response following myocardial infarction both humoral and cellular phase, allowing the identification and semiquantitative analysis of proteins produced during the inflammatory cascade activation and the topographical distribution and expression of proteins and cells involved in myocardial inflammation. Confocal laser scanning microscopy (CLSM) is a relatively new technique for microscopic imaging, that allows greater resolution, optical sectioning of the sample and three-dimensional reconstruction of the same sample. Western blotting used to detect the presence of a specific protein with antibody-antigen interaction in the midst of a complex protein mixture extracted from cells, produced semi-quantitative data quite easy to interpret. Confocal Raman microscopy combines the three-dimensional optical resolution of confocal microscopy and the sensitivity to molecular vibrations, which characterizes Raman spectroscopy. The combined use of western blotting and confocal microscope allows detecting the presence of proteins in the sample and trying to observe the exact location within the tissue, or the topographical distribution of the same. Once demonstrated the presence of proteins (cytokines, chemokines, etc.) is important to know the topographical distribution, obtaining in this way additional information regarding the extension of the inflammatory process in function of the time stayed from the time of myocardial infarction. These methods may be useful to study and define the expression of a wide range of inflammatory mediators at several different timepoints providing a more detailed analysis of the time course of the infarct

    Cardiovascular Involvement in Sepsis.

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    This special issue wants to contribute to a better understanding of cardiac involvement in sepsis. Sepsis is a complex syndrome that has recently been defined as “life-threatening organ dysfunction due to a dysregulated host response to infection”. It should be considered a major public health problem since it affects millions of people worldwide each year, and it accounts for most deaths in critically ill patients. The presence of myocardial dysfunction in sepsis is associated with higher mortality. A great attention has been dedicated to improving our knowledge and understanding of the intricate mechanisms underlying sepsis. However, data from the literature suggest the need to implement strategies to reliably measure sepsis morbidity and mortality. In fact, methods based on analyses of insurance claim data using sepsis-specific codes or separate codes for infection and organ dysfunction are unreliable in informing or measuring the effects of policy changes, and the postmortem diagnosis of sepsis is often elusive since postmortem investigations lack certain pathognomonic macroscopic and histopathological findings. From a morphological and diagnostic point of view, the term “septic disease” has been created to describe the cardiac involvement in the syndrome. However, this definition, rather than describing a morphological finding, was instead referred to the clinical setting. Although in recent years the concept of septic cardiomyopathy has evolved and it involves pathological alterations of myocardial cells in response to the multiplicity of acting mechanism of damage, the importance of structural changes during sepsis is often overlooked. In patients with sepsis, death is usually the result of a progressive multiorgan dysfunction, overlooking the primary infection through the hyperinflammation. The cardiac involvement as fundamental part of septic multiorgan dysfunction syndrome has been discussed for a long time
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