674 research outputs found

    The usefulness of c-Kit in the immunohistochemical assessment of melanocytic lesions

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    C-Kit (CD117), the receptor for the stem cell factor, a growth factor for melanocyte migra- tion and proliferation, has shown differential immunostaining in various benign and malig- nant melanocytic lesions. The purpose of this study is to compare c-Kit immunostaining in benign nevi and in primary and metastatic malignant melanomas, to determine whether c-Kit can aid in the differential diagnosis of these lesions. c-Kit immunostaining was per- formed in 60 cases of pigmented lesions, including 39 benign nevi (5 blue nevi, 5 intra- dermal nevi, 3 junctional nevi, 15 cases of pri- mary compound nevus, 11 cases of Spitz nevus), 18 cases of primary malignant melanoma and 3 cases of metastatic melanoma. The vast majority of nevi and melanomas examined in this study were posi- tive for c-Kit, with minimal differences between benign and malignant lesions. C-Kit cytoplasmatic immunoreactivity in the intraepidermal proliferating nevus cells, was detected in benign pigmented lesions as well as in malignant melanoma, increasing with the age of patients (P=0.007) in both groups. The patient’s age at presentation appeared to be the variable able to cluster benign and malignant pigmented lesions. The percentage of c-Kit positive intraepidermal nevus cells was better associated with age despite other vari- ables (P=0.014). The intensity and percentage of c-Kit positivity in the proliferating nevus cells in the dermis was significantly increased in malignant melanocytic lesions (P=0.015 and P=0.008) compared to benign lesions (compound melanocytic nevi, Spitz nevi, intradermal nevi, blue nevi). Immunostaning for c-Kit in metastatic melanomas was nega- tive. Interestingly in two cases of melanoma occurring on a pre-existent nevus, the melanoma tumor cells showed strong cytoplas- matic and membranous positivity for c-kit, in contrast with the absence of any immunoreac- tivity in pre-existent intradermal nevus cells. C-Kit does not appear to be a strong immuno- histochemical marker for distinguishing melanoma from melanocytic nevi, if we consid- er c-Kit expression in intraepidermal prolifer- ating cells. The c-Kit expression in proliferat- ing melanocytes in the dermis could help in the differential diagnosis between a superfi- cial spreading melanoma (with dermis inva- sion) and a compound nevus or an intradermal nevus. Finally, c-Kit could be a good diagnostic tool for distinguishing benign compound nevi from malignant melanocytic lesions with der- mis invasion and to differentiate metastatic melanoma from primary melanoma

    Petrological study of sorne dark inclusions in hercynian granitoids frorn the Hesperian Massif (Spain)

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    [Resumen] Se estudian algunos enclaves de origen ígneo incluidos en granitoides hercínicos sincinemáticos meso y catazonales situados en la zona Centroibérica. Esta serie de rocas así como otras similares situadas en áreas próximas, y estudiadas por diversos autores, presentan un notable grado de variabilidad composicional, encontrándose desde tipos fuertemente metaalumínicos a otros peralumínicos, e incluso rocas aberrantes fuertemente subsaturadas y con leucita normativa. También se observa, a nivel de afloramiento y microscópico, una fuerte heterogeneidad en las estructuras y en las texturas, debido a la superposici6n de procesos de hibridación y reajustes mineralógicos. Estas transformaciones están además relacionadas en pate con reacciones entre los materiales básicos y los granitoides que las incluyen. En los casos estudiados, la reactividad está realzada por el carácter catazonal de los granitoides, por su riqueza en fase volátil (manifiesta por una considerable proporción de moscovita) y por la imbricación con los procesos metam6rficos regionales y la migmatizaci6n. Por otra parte, se estudian rocas de un pequeño cuerpo plutónico básicJ, intrusivo en un conjunto de metasedimentos de grado medio-alto, próximos a un área de intensa migmatización, y que por sus características pueden corresponderse con algunos de los enclaves básicos incluidos en los granitoides migmáticos inhomogéneos.[Abstract] Several dark inclusions of igneous origin from synkinematic meso and catazonal Hercynian granitoids of the Central Iberian Zone are studied. The rocks of this group of inclusions and of similar ones outcropping in adyacent areas, which have been studied by various authors, showa remarkable degree of compositional variability. They range from strongly meta-aluminous to peraluminous types and even unusual undersaturated rocks or rocks with normative leucite· are known to exist among them. Hybridization processes, together with mineralogical readjus~ments, resulted in a marked textural and structural heterogeneity of the rocks at the scale of an outcrop or under the microscope. Part of these transformations can be related to interaction between the basic material of the inclusions and the enclosing granitoids. In the cases studied, reactivity was enhanced by the catazonal character of the granitoids, their richness in volatiles (as indicated by their considerable amount of muscovite) and their involvment in processes of regional metamorphism and migmatization. The rocks of a small plutonic outcrop intrusive in medium to high grade metasediments are studied.The chemico-mineralogical characteristics of these rocks suggest that they may be comparable withsorpe of the basic inclusions found in masses of the so-called inhomogeneous migmatitic granitoids

    Predicting workout quality to help coaches support sportspeople

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    The support of a qualified coach is crucial to keep the motivation of sportspeople high and help them pursuing an active lifestyle. In this paper,we discuss the scenario in which a coach follows sportspeople remotely by means of an eHealth platform, named u4fit. Having to deal with several users at the same time, with no direct human contact, means that it is hard for coaches to quickly spot who, among the people she follows, needs a more timely support. To this end, in this paper we present an automated approach that analyzes the adherence of sportspeople to their planned workout routines. The approach is able to suggest to the coach the sportspeople who need earlier support due to a poor performance. Experiments on real data, evaluated through classic accuracy metrics, show the effectiveness of our approach

    All-optical trapping and acceleration of heavy particles

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    A scheme for fast, compact, and controllable acceleration of heavy particles in vacuum is proposed, in which two counterpropagating lasers with variable frequencies drive a beat-wave structure with variable phase velocity, thus allowing for trapping and acceleration of heavy particles, such as ions or muons. Fine control over the energy distribution and the total charge of the beam is obtained via tuning of the frequency variation. The acceleration scheme is described with a one-dimensional theory, providing the general conditions for trapping and scaling laws for the relevant features of the particle beam. Two-dimensional, electromagnetic particle-in-cell simulations confirm the validity and the robustness of the physical mechanism.Comment: 10 pages, 3 figures, to appear in New Journal of Physic

    Reproductive aspects of the velvet belly lantern shark Etmopterus spinax (Condrichthyes: Etmopteridae), from the central western Mediterranean sea. Notes on gametogenesis and oviducal gland microstructure.

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    In this paper, the reproductive biology of the velvet belly lanternshark Etmopterus spinax was analyzed in Sardinian waters (central western Mediterranean). This species was sexually dimorphic with females growing to a larger size than males. Marked sexual dimorphism in size was also observed along the vertical gradient. Histological analysis of gonads was very useful in assigning macroscopical maturity stages. The investigation on the microstructure of oviducal gland (OG) highlighted four morphofunctional zones with mucous and/or proteic secretions according to the zone and to their specific functions and development. Sperm in the OG was found for the first time in E. spinax. The localization of sperm storage tubules deeper in OG suggested long-term sperm storage, which is in agreement with the long reproductive cycle described. This species matured late, specifically at 80.7% and 79% at the maximum observed size for females and males respectively. Mature specimens were found throughout the year with pregnant females observed in winter and autumn. A low fecundity was observed with a mean ovarian fecundity of 16.5 mature follicles

    Polytherapy in bone regeneration: clinical applications and preliminary considerations.

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    Polytherapy, namely the simultaneous application of three fundamental elements necessary for bone regeneration (growth factors, osteogenic cells and osteocnductive scaffolds) seems to lead to a very high success rate in the treatment of complex non-union (NU) cases and critical bone defects. NU are reported in 5–10% of long bone fractures. The use of autologous bone grafts has been long-considered the gold standard for the treatment of these cases. However the harvesting procedure from the iliac crest increases surgery time and presents some donor site complications which may be elevated. In recent years, surgeons have some alternatives to autologous grafting such as: application of organic or synthetic bone substitute, application of mesenchymal stromal cells (MSC) or growth factors (GF). In the literature there are many studies available about their application in monotherapy, but unfortunately the healing rate doesn't exceed 90%. Polytherapy seems to be a logical option to improve the healing rate, nevertheless, there are not still extensive studies that validate this strategy and moreover, some questions are not resolved

    New insights on the systematics of echinoids belonging to the family Spatangidae Gray, 1825 using a combined approach based on morphology, morphometry, and genetics

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    Spatangoids are probably the least resolved group within echinoids, with known topological incongruencies between phylogenies derived from molecular (very scarce) and morphological data. The present work, based on the analysis of 270 specimens of Spatangidae (Echinoidea, Spatangoida) trawled in the Sardinian seas (Western Mediterranean), allowed us to verify the constancy of some characters that we consider to be diagnostic at the genus level —such as the path of the subanal fasciole and the relationship between labrum and adjacent ambulacral plates —and to distinguish two distinct forms within the studied material. Based on morphological characters, morphometrics, and molecular analyses (sequencing of two mitochondrial markers: cytochrome c oxidase subunit1 (COI) and 16S), most of the individuals were classified as morphotype A and attributed to the species Spatangus purpureus, the most common spatangoid in the Mediterranean Sea, while a few corresponded to a different morphotype (B), genetically close to the species Spatangus raschi. Preliminary morphological analyses seemed to indicate that morphotype B specimens from Sardinia are slightly different from S. raschi and from Spatangus subinermis individuals, the second species of the family known to occur in the Mediterranean Sea. On the basis of morpho-structural observations and molecular analyses, comparing Mediterranean living forms with species from other areas (Central Eastern Atlantic, North Sea and neighboring basins, South African Sea, Philippines and Indonesian Archipelago, New Zealand, and Hawaiian Islands), the clear distinction of S. purpureus from several other species classified as Spatangus was confirmed. Based on the morphological and genetic differences, we propose to maintain the genus Spatangus including in it only the type species S. purpureus among the living species and to establish the new genus Propespatagus nov. gen. to include several other species previously classified as Spatangus. The clear distinction among different genera was also detected in fossil forms of Spatangus, Propespatagus nov. gen., and Sardospatangus (†) from the European Oligo-Miocene sedimentary rocks of Germany; the Miocene of Ukraine, Italy, and North Africa; the Plio-Pleistocene of Italy; and the Mio-Pliocene of Florida (USA). The new data can help in addressing taxonomic ambiguities within echinoids, as well as in improving species identification, and hence biodiversity assessments in the Mediterranean region

    Assessing thornback ray growth pattern in different areas of Western-Central Mediterranean Sea through a Multi-Model Inference analysis

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    The lack of information on age validation often affects ageing studies in cartilaginous fish, even in the most common species. Recently, the annual growth band deposition pattern has been directly validated for thornback ray in the Mediterranean Basin, thus providing a highly reliable protocol for age reading. In this regard, taking advantage of this new information, the present study aims to investigate this species growth for the first time over a wide area of the Western and Central Mediterranean Sea, involving four different FAO geographic sub-areas. In order to provide an accurate description of the species growth, different models were fitted to the age-length data obtained from the observation of vertebral centra thin sections. A total of 720 specimens were analysed (358 females and 362 males) with total length ranging between 11.5 and 86.4 cm. The corrected Akaike's Information criterion (AICc) indicated, among the tested models, the three-parameter von Bertalanffy function as the most robust in describing the species growth. Growth modelling outcomes revealed the thornback rays as capable of growing relatively fast during the first years; the growth rate gradually slows down allowing maximum sizes of about 90–100 cm in total length to be reached. Significant discrepancies in the growth pattern were found between sexes in all investigated areas with the only exception being in the Northern Tyrrhenian Sea. Differences in growth patterns were observed between areas, specifically in the estimated growth rate of the species for each sub-region. The present study, confirmed the importance of the availability of a validated ageing protocol and testing multiple growth models. Moreover, our results highlighted the urgent need to investigate a species growth in a wide geographic area, searching also for possible differences at sub-region level. Providing this information could indeed allow eventual management plans to be adapted to the exact growth pattern that the species exhibit in the region, in this way increasing their effectiveness

    A taxonomic survey of female oviducal glands in chondrichthyes: A comparative overview of microanatomy in the two reproductive modes

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    Oviducal glands (OGs) are distinct expanded regions of the anterior portion of the oviduct, commonly found in chondrichthyans, which play a key role in the production of the egg in-vestments and in the female sperm storage (FSS). The FSS phenomenon has implications for understanding the reproductive ecology and management of exploited populations, but little information is available on its taxonomic extent. For the first time, mature OGs from three lecithotrophic oviparous and four yolk-sac viviparous species, all considered at risk from the fishing impacts in the central western Mediterranean Sea, were examined using light microscopy. The OG microanatomy, whose morphology is generally conserved in all species, shows differences within the two reproductive modalities. Oviparous species show a more developed baffle zone in respect to viviparous ones because of the production of different egg envelopes produced. Among oviparous species, Raja polystigma and Chimaera monstrosa show presence of sperm, but not sperm storage as observed, instead, in Galeus melastomus and in all the viviparous sharks, which preserve sperm inside of specialized structures in the terminal zone
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