1,721,057 research outputs found
Fish immunology after the post-genomic era.
No full textThe research on fish immunology has risen impressively over the last decades, providing deep insights into the evolution of the immune system of vertebrates and underlying genetic networks, but also discovering some peculiarities, mainly related to ancestral or heavily specialised molecular and cellular characters. Gathered information has built a sound platform to further accomplish the elucidation of evolutionary processes and boost application-based research to monitor fish health and contrast old and emerging diseases. The extensive cloning of genes encoding for immune-regulatory molecules, together with the sequencing of many fish genomes, provided scientists with a comprehensive panel of nucleotide sequences. Therefore, fish have become the main research models for cold-blooded vertebrates. It is expected in the near future that much research will be addressed to revive the more arduous work remaining, namely, that of associating molecules, cell features and anatomy with function.
Considerable efforts have been, and will be, directed toward a careful interpretation of differences among species, disclosure of relation to fish habits, and interactions of individual specimens with the changing (and challenging) environment. When proposing expert reviews on some research topics that pursue these intriguing perspectives, this Special Issue of Fish and Shellfish Immunology aimed at updating current knowledge on fish immunology. This Special Issue arises from outstanding contributions presented at the Symposium of the European Organisation of Fish Immunology (EOFFI) held in Viterbo, Italy, on May 2010. As a result of the wide and qualified participation of scientists from all the continents, the Organisation has been renamed as the new International Society of Fish and Shellfish Immunology (ISFSI, www.isfsim.org), aiming at extending the scientific interests and activities to shellfish immunology
Monoclonal antibodies in fish immunology: Identification, ontogeny and activity of T- and B-lymphocytes
No full textThe current status on the antibodies that have been produced against teleost fish immuno-
globulins, immunoglobulin-bearing cells (B-cells), thymocytes and T-cells is reviewed. An
updated list of monoclonal antibodies is reported together with their antigen specificity, their use
in the detection of cross-reacting cells, and their eventual use as markers of fish leucocyte
subpopulations. The evidence obtained with monoclonal antibodies on the ontogeny of lymphoid
cells and functions of lymphocyte subpopulations is presented. The possibility to create a common
nomenclature for fish monoclonal antibodies is discussed
Spermatozoa and chronic treatment with finasteride: a TEM and FISH study
No full textFinasteride is a specific inhibitor of the 5alpha reductase enzyme originally approved for the treatment of benign prostatic hypertrophy and also for the treatment of androgenetic alopecia (AGA) in men at a dose of 1 mg/day. We report on three cases of young men recruited at our Centre for Male Infertility who had used finasteride for five years. Semen quality was investigated by light microscopy to evaluate sperm concentration and motility. Sperm morphology was performed by transmission electron microscope (TEM) and the data were analyzed. The presence of Y microdeletions was investigated by PCR. Meiotic segregation was explored by fluorescence in situ hybridization (FISH). Patient 1 was azoospermic, patients 2 and 3 showed a normal sperm concentration and severely reduced progressive motility. TEM analysis revealed altered sperm morphology consistent with necrosis and FISH data revealed elevated diploidy and sex chromosome disomy frequencies. This examination was repeated 1 year after the men had suspended the use of finasteride, without receiving any other treatment. A recovery of spermatogenetic process was observed. Motility and morphology improved whereas the meiotic pattern did not change presenting elevated diploidy and sex chromosome disomy frequency
Oxygen Harvesting from Eukaryotic Green Algae Cultivation on Moon’s Surface
Full text linkThe presence of oxygen in the Earth atmosphere represents the key resource for the human life. Outside that thin layer of atmosphere, every place is naturally unsuitable for life. Nowadays, the vital resources on board the ISS, the only manned outpost in space, are constantly resupplied directly from Earth in an open-loop cycle. Different strategies must be adopted for deep-space manned explorations in order to ensure the mission independence from Earth. The main idea behind this work is to support the incoming manned mission towards the Moon by recycling part of the emitted carbon dioxide and the urine produced by the human crew to feed a green algae cultivation in a dedicated photobioreactor aimed to close-loop oxygen production. Indeed, oxygen availability opens to a variety of new scenarios for planetary colonization and exploration. A great amount of work on this side has been carried out in the context of MELiSSA Project, whose main objective is to set-up a regenerative life support system to reach the highest degree of autonomy to produce water, food, and oxygen by the mission wastes. Leveraging on the MELiSSA Project experiences and on an ISS photobioreactor demonstrator developed by DRL, we propose to use a Chlorella Vulgaris cultivation in a photobioreactor placed in a space system, properly designed for its survival on the Moon’s surface. In this work we present the basic principle of photosynthesis linked to the hyperparameters that mostly affect the Chlorella Vulgaris cultivation, the set-up of the numerical simulations used for the design of the photobioreactor capable to work in Moon environmental conditions and the preliminary sizing of the system from a thermal and power supply point of view
Ontogeny of thymocytes in sea bass Dicentrarchus labrax: studies with monoclonal antibodies.
No full textThe monoclonal antibody DLT15 directed against thymocytes of the sea bass Dicentrarchus labrax specifically recognised an antigen determinant(s) expressed during development of thymic lymphoid cells. While immunoreaction is excluded from lymphoblast-like cells present in the thymic anlage, it was first detected one month posthaching in thymocytes. Thereafter, a marked increase in number of immunoreactive cells occurred mostly in the outer region of the thymus. This study aimed to analyse the chronology and some features of thymocyte differentiation
F-ACTIN DISTRIBUTION IN THE OVARIES OF PRE-VITELLOGENIC AND VITELLOGENIC BLACK BLOWFLIES, PHORMIA-REGINA (MEIGEN) (DIPTERA, CALLIPHORIDAE)
No full textThe spatial distribution of F-actin microfilaments in the ovaries of pre-vitellogenic and vitellogenic female black blowflies, Phormia regina (Diptera : Calliphoridae), as the females shift from a sugar to a liver diet, is determined using rhodamine-labelled phalloidin (rh-phalloidin). During the pre-vitellogenic stages of ovarian development (i.e. corresponding to a sugar diet) a single bright fluorescent layer marks the interface between follicle cells and the oocyte. Fluorescence is also most evident at the inner surface of the ring canals of the nurse cells. This is observed in the nurse cells both in the distal part of the germarium, and in the vitellogenic growing oocyte. However, when liver-fed (i.e. necessary for vitellogenesis), 2 bright fluorescent layers are observed at the follicle cell-oocyte interface. In addition, the cytoplasm of the nurse cells during vitellogenesis appears full of fluorescent microfilaments and the actin rings are found to increase in size and thickness. The changing organization of the F-actin microfilaments in the follicles during the process of both egg chamber and oocyte formation is discussed and possible functions considered
Immunocytochemical detection and cytomorphology of lymphocyte subpopulations in a teleost fish Dicentrarchus labrax
No full textThe monoclonal antibodies DLT15 and DLIg3
directed against thymocytes and serum immunoglobulins
of the sea bass (Dicentrarchus labrax, L.) were used to
study cells from the thymus, head kidney, spleen, gut-associated
lymphoid tissue and peripheral blood leukocytes
of this fish by immunofluorescence and pre-embedding
immunoelectron microscopy. Immunofluorescence
and flow cytometry of leukocyte fractions revealed
a large number of DLT15-positive cells in the
thymus (~80%) and intestine (~55%) and fewer cells in
the spleen (~7%), head kidney (~6%) and peripheral
blood (~3%). DLT15-positive cells had two main morphologies,
both detectable among thymocytes: a large
round heterochromatic nucleus with light sparse cytoplasm
(type a) and an irregular and heterocromatic nucleus
with cytoplasm rich in polysomes and mitochondria
(type b). Type b was most represented in spleen,
head kidney, intestine and blood. We suggest that the
type b morphology represents more differentiated lymphocytes.
Flow cytometry revealed numerous DLIg3-
positive cells in the head kidney (~33%), spleen (~30%)
and peripheral blood leukocytes (~21%) and fewer positive
cells in the intestine (~3%) and thymus (~2%).
DLIg3-positive cells had the morphology of lymphocytes
(with a large round nucleus) or macrophages in all
tissues. Plasma cells lacked membrane immunoreactivity.
This is the first ultrastructural characterisation of putative
T- and B-lymphocyte subpopulations in a fish species;
these subpopulations are differentially distributed
in teleost lymphoid organs
Immunohistochemistry of gut-associated lymphoid tissue of the sea bass Dicentrarchus labrax (L.)
No full textHistology revealed scattered lymphoid cells at all levels of the digestive tract of the sea bass Dicentrarchus labrax (L.), notably in the mucosa and submucosa. Immunohistochemistry with monoclonal antibodies against T cells (DLT15) and immunoglobulin-bearing cells (DLIg3 and DLIg13) demonstrated
the presence of a gut-associated lymphoid tissue. Quantitative analysis showed that the concentration of DLT15-positive cells largely exceeded that of Ig-bearing cells, while the number and the distribution of DLIg3- and DLIg13-immunoreactive cells were superimposable. An apparent gradient in the number of lymphoid cells was present, concentrating them towards the anus. This suggests that, as in other fish species, the posterior gut acquired higher immunological relevance
FINE-STRUCTURE OF THE CHORION AND MICROPYLE OF THE SEA BASS EGG DICENTRARCHUS-LABRAX (TELEOSTEA, PERCICHTHYDAE)
No full textThe fine structure of the chorion and micropyle of mature unfertilized eggs of the sea bass Dicentrarchus labrax was examined by scanning and transmission electron microscopy. The chorion consists of three layers: a thin electrondense outer layer, a paracrystalline middle layer and a thick inner layer consisting of 12 electrondense filamentous lamellae alternating with interlamellar material of lower electrondensity. The two more external layers are crossed by pore canals opening on the egg surface. The funnel-type micropyle is located at the animal pole of the egg. The walls of the micropylar canal have circular, rib-like thickenings reflecting the stratified inner layer of the chorion. The results are discussed and compared with those in other Teleostea
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