Phase transitions and critical phenomena in the two-dimensional Ising model with dipole interactions: A short-time dynamics study.

The ferromagnetic Ising model with antiferromagnetic dipole interactions is investigated by means of Monte Carlo simulations, focusing on the characterization of the phase transitions between the tetragonal liquid and stripe of width h phases. The dynamic evolution of the physical observables is analyzed within the short-time regime for 0.5≤δ≤1.3, where δ is the ratio between the short-range exchange and the long-range dipole interaction constants. The obtained results for the interval 0.5≤δ≤1.2 indicate that the phase transition line between the h=1 stripe and tetragonal liquid phases is continuous. This finding contributes to clarifying the controversy about the order of this transition. This controversy arises from the difficulties introduced in the simulations due to the presence of long-range dipole interactions, such as an important increase in the simulation times that limits the system size used, strong finite size effects, as well as to the existence of multiple metastable states at low temperatures. The study of the short-time dynamics of the model allows us to avoid these hindrances. Moreover, due to the fact that the finite-size effects do not significantly affect the power-law behavior exhibited in the observables within the short-time regime, the results could be attributed to those corresponding to the thermodynamic limit. As a consequence of this, a careful characterization of the critical behavior for the whole transition line is performed by giving the complete set of critical exponents.

Dermatosis perforantes: presentación de 8 casos / Perforating dermatosis: report of 8 cases

Las dermatosis perforantes (DP) o enfermedades por eliminación transepidérmica son un grupo de entidades caracterizadas por la extrusión de material dérmico alterado a través de la epidermis que incluye a la colagenosis perforante reactiva, la elastolisis perforante serpiginosa, la foliculitis perforante y la enfermedad de Kyrle. Se caracterizan por la aparición de pápulo-nódulos centrados por tapones o costras queratósicas, pruriginosos. Entre las opciones terapéuticas se describen los antihistamínicos, fototerapia y corticoides intralesionales, con resultados variables. Objetivos. Describir 8 casos de dermatosis perforante diagnosticados en nuestro servicio. Materiales y Métodos. Se realizó un estudio retrospectivo, observacional y descriptivo que evaluó las características clínicas, histológicas y la asociación con patología sistémica de los pacientes con diagnóstico histológico de dermatosis perforante que concurrieron a nuestro servicio entre septiembre de 2006 y julio de 2010.Resultados. Se diagnosticaron 8 pacientes con dermatosis perforante. Del total, 5 (62,5%) fueron hombres y 3 mujeres (37,5%). La edad media de presentación fue de 57,12 años (37-71 años); 6 (75%) correspondían a enfermedad de Kyrle y 2 (25%) a foliculitis perforante; 6 (75%) se asociaban a insuficiencia renal crónica, 6 (75%) a diabetes mellitus, 1 (12,5%) a insuficiencia renal aguda y 6 (75%) a enfermedad cardiovascular. Conclusiones. Si bien la mayoría de nuestros pacientes tenían antecedentes de diabetes y/o insuficiencia renal crónica como se describe en la literatura, cabe destacar que en uno de ellos no se encontró ninguna de estas asociaciones. Adicionalmente, el 75% de los pacientes tenía antecedentes de enfermedad cardiovascular. Encontramos una mayor incidencia en hombres (62,5%) a diferencia de lo reportado en algunos trabajos (AU)

Perforating dermatosis (DP) comprises a group of diseases characterized by the extrusion of dermic debris through the epidermis. It includes reactive perforating collagenosis, perforating folliculitis, elastosis perforans serpiginosa and Kyrle's disease. It presents as multiple pruritic papulo nodules centered by a keratotic plug. Antihistamines, phototherapy and intralesional steroids are among the therapeutic options described, with variable results. Objectives. To describe 8 cases of perforating dermatosis diagnosed in our department. Materials and Methods. We conducted a retrospective, observational and descriptive study evaluating clinical and histological features and association with systemic disease, of the patients with a biopsy confirmed, perforating dermatosis between September 2006 and July 2010. Results. Eight patients with perforating dermatosis were diagnosed. Of them, 5 (62,5%) were male and 3 female (37,5%). Mean age of presentation was 57,12 years (37-71 years); 6 (75%) corresponded to Kyrle's disease and 2 (25%) to perforating folliculitis; 6 (75%) were associated with chronic renal insufficiency, 6 (75%) with diabetes mellitus, 1 (12,5%) with acute renal insufficiency and 6 (75%) with cardiovascular disease. Conclusions. Although most of our patients had a history of chronic renal insufficiency or diabetes, as described in the literature, in one of them no associated disease was found. Furthermore, 75% of the patients presented with cardiovascular disease. Unlike previous reports, we found agreater incidence in men (62,5%) over women (AU)

Primary carnitine deficiency and sudden death: in vivo evidence of myocardial lipid peroxidation and sulfonylation of sarcoendoplasmic reticulum calcium ATPase 2.

OBJECTIVES: Primary carnitine deficiency is an autosomal recessive disorder caused by mutations in the SLC22A5 gene which results in impaired carnitine transport, cytosolic fatty acid accumulation and impaired beta oxidation. The disease is associated with cardiomyopathy and arrhythmias, but the mechanism is unknown. We hypothesized that carnitine deficiency results in increased myocardial oxidative stress. METHODS: We evaluated a 22-year-old woman with primary carnitine deficiency and ventricular fibrillation, as well as her first-degree relatives. RESULTS: Sequencing of SLC22A5 identified two deleterious mutations (A142S and R488H) and a novel mutation predicted to be a splice variant. Histology demonstrated increased myocardial lipid deposition and swollen mitochondria. Immunohistochemistry demonstrated accumulation of the reactive aldehyde 4-hydroxy-2-nonenal, indicative of increased lipid peroxidation, and sulfonylation of sarcoendoplasmic reticulum calcium ATPase 2 at cysteine 674. CONCLUSIONS: These findings suggest that increased oxidant stress may contribute to myocardial dysfunction and arrhythmogenesis in this disorder.

Immunolocalization of a lipase-like protein in the reproductive apparatus of female Phlebotomus papatasi, at various stages of the gonotrophic cycle.

In female phlebotomine sandflies, little is known about the reproductive accessory glands that presumably contribute to egg production and/or oviposition. The main protein secreted in the accessory glands of female Phlebotomus papatasi was recently characterised as a lipase-like protein, the first to be found in the female accessory glands of any insect. This protein, named PhpaLIP (for Phlebotomus papatasi lipase), has now been detected and localized in the reproductive tissues of female P. papatasi, at different stages of the gonotrophic cycle, using a polyclonal anti-PhpaLIP serum and both confocal scanning laser and immuno-electron microscopy. PhpaLIP appears to be always present in the accessory glands (with a secretory peak shortly before oviposition) but was also detected in the follicle cells of the ovarioles, within the developing vitelline envelope, and in the oviducts. The results are discussed in relation to the functions that PhpaLIP could have during the gonotrophic cycle, in the various reproductive structures of female P. papatasi.

Differential tissue expression of a calpastatin isoform in Xenopus embryos.

This study is aimed at demonstrating the role played by a calpastatin isoform (Xcalp3) in Xenopus embryos. A specific monoclonal antibody (mAb) was raised against a glutathione S-transferase (GST)-Xcalp3 fusion protein and characterized by immunoblotting and confocal fluorescence microscopy on stage 20-36 embryos. Under these conditions, calpastatin reactivity is associated with a major 110kDa protein fraction and preferentially expressed by notochord and somitic cells. In notochord cells, anti-calpastatin reactive sites were initially restricted to the luminal space of the vacuoles and later became diffused throughout the cytoplasm. In contrast, anti-calpastatin reactive sites in somitic cells were initially diffused throughout the cytoplasm and became restricted to a few intracellular granules in the later developmental stages. At the ultrastructural level, notochord cells appeared as flattened discs containing several vacuoles and numerous electron-dense granules. During transition from stages 26 to 32, electron-dense granules were gradually reduced in number as vacuoles enlarged in size and losed their calpastatin reactivity. Electron-dense granules were also present in myoblast cells and their number gradually reduced during development. To determine whether these observations bear any causal relationship to the calpain/calpastatin system, a number of Xenopus embryos were examined both ultrastructurally and histochemically following exposure to a specific calpain inhibitor (CI3). Under these conditions, Xenopus embryos exhibited an altered right-left symmetry and an abnormal axial shortening. In CI3-treated stage 32 embryos, notochord cells had a reduced vacuolar extension and exhibited at the same time an increase in granular content. The overall morphology of the somites was also distorted and myoblasts were altered both in shape and granular content. Based on these findings, it is concluded that the calpain/calpastatin may play an important role in the control of notochord elongation and somite differentiation during Xenopus embryogenesis.

High levels of human chitotriosidase hinder the formation of peritrophic membrane in anopheline vectors.

In the Anopheles midgut, Plasmodium falciparum produces a specific chitinase able to penetrate the blood meal surrounding the chitin-containing peritrophic membrane (PM). High levels of an analogous chitinase, chitotriosidase (CHIT), may be found in human blood, being the markers of macrophage activation. To verify the hypothesis that CHIT present in malaria patient blood could help parasite to overcome PM, we carried out a bioassay by feeding Anopheles stephensi females on an artificial apparatus that contained human blood from four different sources and with different chitinase concentrations: (1) healthy donors, as negative controls; (2) patients with malaria; (3) patients with Gaucher disease; and (4) whole blood enriched with commercial P. falciparum chitinase, as positive controls. After 16, 20 and 24 h of bloodfeeding, mosquitoes were dissected to extract the midgut and assess the effect of the different chitinases on membrane structure. Optical microscopy showed that formation of PM was clearly complete after 16 h in the posterior midgut from Anopheles already fed with healthy donor bloods. By contrast, PM formation was visible after 16 h in the posterior midgut of mosquitoes fed with malaria and Gaucher patient bloods but appeared clearly damaged at 20 and 24 h. At the same time, the PM formation was almost completely inhibited in the midgut of Anopheles fed with P. falciparum chitinase-enriched bloods. These alterations were clearly confirmed by transmission electronic microscopy. In the present paper, we demonstrate that human CHIT from different sources is active on anophelines' PM.

Biological activity of cytokines: an evolutionary perspective.

It appears evident that teleost fish are at present the vertebrate group in which, excluding mammals, most information on the immune system is available. However, despite the great impetus on the discovery of genes homologous to mammalian immunomodulatory molecules, the knowledge on biological activities exerted by cytokines is meager. This review reports the present knowledge on the biological activities of cytokine-like and cytokines in invertebrates and cold-blooded vertebrates.

Viral particles of the endogenous retrovirus ZAM from Drosophila melanogaster use a pre-existing endosome/exosome pathway for transfer to the oocyte.

BACKGROUND: Retroviruses have evolved various mechanisms to optimize their transfer to new target cells via late endosomes. Here, we analyzed the transfer of ZAM, a retroelement from Drosophila melanogaster, from ovarian follicle cells to the oocyte at stage 9-10 of oogenesis, when an active yolk transfer is occurring between these two cell types. RESULTS: Combining genetic and microscopic approaches, we show that a functional secretory apparatus is required to tether ZAM to endosomal vesicles and to direct its transport to the apical side of follicle cells. There, ZAM egress requires an intact follicular epithelium communicating with the oocyte. When gap junctions are inhibited or yolk receptors mutated, ZAM particles fail to sort out the follicle cells. CONCLUSION: Overall, our results indicate that retrotransposons do not exclusively perform intracellular replication cycles but may usurp exosomal/endosomal traffic to be routed from one cell to another.

Lipase and antibacterial activities of a recombinant protein from the accessory glands of female Phlebotomus papatasi (Diptera: Psychodidae).

The reproductive accessory glands of the adult female have a functional versatility in insects, contributing to reproduction in various ways. The major protein secreted by the accessory glands of female Phlebotomus papatasi (Diptera, Psychodidae) has already been characterised and named PhpaLIP (for P. papatasi lipase) because, in terms of its amino-acid sequence, it is very similar to a wide range of vertebrate lipases. The gene coding for PhpaLIP has now been cloned into a pQE30 vector and expressed in Escherichia coli. When the recombinant PhpaLIP was tested in vitro, it was found to have not only lipase-like activity (when p-nitrophenyl caprylate was used as the substrate) but also specific antibacterial activity against some Gram-positive and Gram-negative bacteria. The possible physiological roles of PhpaLIP in P. papatasi are discussed, in the light of these results.

Experimental and computational validation of BDTPS using a heterogeneous boron phantom.

The idea to couple the treatment planning system (TPS) to the information on the real boron distribution in the patient acquired by positron emission tomography (PET) is the main added value of the new methodology set-up at DIMNP (Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione) of University of Pisa, in collaboration with the JRC (Joint Research Centre) at Petten (NL). This methodology has been implemented in a new TPS, called Boron Distribution Treatment Planning System (BDTPS), which takes into account the actual boron distribution in the patient's organ, as opposed to other TPSs used in BNCT that assume an ideal uniform boron distribution. BDTPS is based on the Monte Carlo technique and has been experimentally validated comparing the computed main parameters (thermal neutron flux, boron dose, etc.) to those measured during the irradiation of an ad hoc designed phantom (HEterogeneous BOron phantoM, HEBOM). The results are also in good agreement with those obtained by the standard TPS SERA and by reference calculations carried out using an analytical model with the MCNP code. In this paper, the methodology followed for both the experimental and the computational validation of BDTPS is described.

An epithermal facility for treating brain gliomas at the TAPIRO reactor.

An epithermal facility for treating patients with brain gliomas has been designed and is under construction at the fast reactor TAPIRO at ENEA Casaccia (Italy). The calculational design tools employed were the Monte Carlo codes MCNP/MCNPX together with the DSA in-house variance reduction patch. A realistic anthropomorphic phantom ("ADAM") was included to optimise dose profiles and in-phantom treatment-planning figures-of-merit. The adopted approach was to minimise the treatment time whilst maintaining a reasonable therapeutic ratio. It is shown that TAPIRO, in spite of its low power of 5 kW, is able to provide an epithermal beam that is of good quality and of sufficient intensity to allow a single beam patient irradiation, under conservative assumptions, of 50 min.

Formation of the egg envelope of a teleost, Dicentrarchus labrax (L.): immunochemical and cytochemical detection of multiple components.

The formation of the egg envelope in a teleost, Dicentrarchus labrax (L.), was analysed at histological and ultrastructural level. The sequential deposition of three main layers (Z1, Z2 and Z3) constitutes the extracellular matrix throughout oocyte development. Various findings indicate that these subunits are biochemically distinct: (1) periodate- and phosphotungstic acid-reactive carbohydrates are obviously detected only in the Z1, that constitutes the initial deposit of the egg envelope in early lipidic oocytes; (2) a monoclonal antibody (DLE7) against egg envelope polypeptides did not immunostain the Z1 and the underlying Z2; (3) the antigenic determinants recognised by DLE7, thought to be exogenous in origin (synthesised in the liver), are incorporated in the inner layer (Z3). In addition, DLE7 immunostained a thin layer, assembled together with Z3. This line has not yet been described in teleost eggs and was named Z1a. This study first describes at fine cytological level the contribution of exogenous proteins to formation of the different egg envelope layers. Results obtained with conventional, immunochemical and cytochemical techniques suggest multiple synthetic sources (exogenous and follicular) of egg envelope proteins.

A mammalian-like lipase gene is expressed in the female reproductive accessory glands of the sand fly Phlebotomus papatasi (Diptera, Psychodidae).

A lipase-like protein (PhpaLIP) was identified as the major protein component in the secretion of the female reproductive accessory glands of the sand fly Phlebotomus papatasi. The full-length cDNA encoding this protein was isolated and its nucleotide sequence determined. The deduced translational product of the gene contains a GFSFG motif, consistent with a GXSXG consensus, which is shared by most bacterial and eukaryotic hydrolases. Transcriptional analysis of the PhpaLIP gene showed that its expression is female-specific, and is also detectable in districts other than accessory glands, suggesting that it might play different functions. Taken together with the observation of sequence similarity shared by PhpaLIP and mammalian lipases, the demonstration of the presence of lipase activity in the accessory gland secretion suggests a possible biological role of PhpaLIP gene product.

Foliculitis en penacho / Tufted hair folliculitis

Presentamos tres pacientes, dos mujeres y un varón, con diagnóstico de foliculitis en penacho, caracterizada por áreas de alopecia cicatrizal dentro de las cuales emergen conglomerados pilosos de un único orificio folicular. Una de las pacientes fue tratada con infiltraciones con corticoides y nadifloxacina tópica; la otra, con corticoides tópicos y queratolíticos, y el paciente varón, con isotretinoína oral. En los tres se obtuvo una mejoría parcial. La FEP sería una variante de la foliculitis decalvante, caracterizada por la formación del penacho piloso como fenómeno principal, evolución tórpida y tratamiento dificultoso

Foliculitis en penacho / Tufted hair folliculitis

Presentamos tres pacientes, dos mujeres y un varón, con diagnóstico de foliculitis en penacho, caracterizada por áreas de alopecia cicatrizal dentro de las cuales emergen conglomerados pilosos de un único orificio folicular. Una de las pacientes fue tratada con infiltraciones con corticoides y nadifloxacina tópica; la otra, con corticoides tópicos y queratolíticos, y el paciente varón, con isotretinoína oral. En los tres se obtuvo una mejoría parcial. La FEP sería una variante de la foliculitis decalvante, caracterizada por la formación del penacho piloso como fenómeno principal, evolución tórpida y tratamiento dificultoso (AU)

Cytology of lymphomyeloid head kidney of Antarctic fishes Trematomus bernacchii (Nototheniidae) and Chionodraco hamatus (Channicthyidae).

Species that live in extreme conditions have specially adapted physiology and tissue/organ organisation. The adaptation of lymphoid organs to low temperatures in polar species could be an original field of study, indicating how the immune system works under extreme conditions. In fishes, the head kidney is a key organ for immunity and here the cytology of this organ is studied in two common Antarctic species: Trematomus bernacchii and Chionodraco hamatus. Ultrastructural analysis revealed heterogeneity of epithelial cells, with reticular cells, subcapsular- and perivascular-limiting cells. Differences in the size and morphology of epithelial cells were observed between the polar species and warm water species of fish. Intermingled with epithelial cell leucocytes, such as lymphocytes, thrombocytes and macrophages, had comparable morphology in both species, contrary to sharp differences observed in the morphology of erythrocytes and granulocytes. The functional adaptation of the head kidney to the low temperatures of polar water is discussed.

Ovarian hyperstimulation-like syndrome after administration of triptorelin to a woman with endometriosis.

Ovarian hyperstimulation after a single dose of gonadotropin-releasing hormone (GnRH) analog is a rare phenomenon. A case of ovarian hyperstimulation-like syndrome after sole administration of triptorelin (Decapeptyl 3.75 mg) is reported in a woman who had undergone surgery for an endometriotic cyst. After administration of the drug, abdominal pressure increased with nausea and diffuse pelvic pain. Ultrasound examination showed bilateral enlargement of the ovaries (right 74 x 62 mm, left 62 x 53 mm), more than 10 follicles ranging in diameter from 15-25 mm, proliferative endometrium 7 mm thick and fluid in the Douglas pouch up to 25 x 23 mm thick. Estradiol plasma level was in the normal range. The syndrome spontaneously resolved in the course of treatment and a spontaneous pregnancy occurred when the triptorelin effect disappeared.

Comparative spermatology in Plecoptera (Insecta). II. An ultrastructural investigation on four species of Systellognatha.

Sperm structure of four Systellognatha species, Dinocras cephalotes (Curtis, 1827) and Perla grandis (Rambur, 1841), family Perlidae, Siphonoperla torrentium (Pictet, 1841), family Chloroperlidae, and Isoperla grammatica (Poda, 1761), family Perlodidae, was investigated by light microscopy, scanning and transmission electron microscopy, and immunofluorescence microscopy. The spermatozoa of all the species are filiform and flagellate; they have an elongated compact nucleus, topped by either a bi-layered or three-layered acrosomal complex, and a '9+9+2' axoneme flanked by two mitochondrial derivatives. However, some variations have been observed, particularly regarding the morphology of the acrosomal complex, the shape of the nucleus, two more or less evident accessory bodies flanking the axoneme and the degree of crystallisation of the mitochondrial derivatives. Our results support the suggestion that Systellognatha is a monophyletic group, showing a single sperm pattern. Chloroperlidae and Perlodidae retain the plesiomorphic condition of some sperm characters while Perlidae show some autoapomorphies. A phylogenetic affinity between Plecoptera and the other orders of Polyneoptera has been confirmed.

The immune system of sea bass, Dicentrarchus labrax, reared in aquaculture.

The sea bass Dicentrarchus labrax is one the most important seawater fish species of south Europe and Mediterranean aquaculture, and studies on its immune system are important for both scientific and applied purposes. In this paper, we summarise the results obtained in studies of the immune system in this species, and present original data on cell-mediated acquired immune response.