Transient ischemic attack and minor stroke as "surgeons affairs": a narrative review.

OBJECTIVE: The scope of this paper is to review the subtypes of transient ischemic attack (TIA) and minor stroke (mS) in which a surgical treatment is needed, discussing the importance and the timing of a multidisciplinary approach, in order to achieve an optimized management and prevent major strokes or other critical complications. MATERIALS AND METHODS: The keywords "transient ischemic attack," "minor stroke," "surgical treatment," "vascular surgery," "heart surgery," "neurosurgery," and "multidisciplinary" were searched using MEDLINE, EMBASE, and Scopus. Relevant search results were discussed by the authors for references inclusion. RESULTS: Notwithstanding that best medical therapy is usually the first choice for the most part of cases, there are specific but recurrent etiologies that must be properly recognized because of a potential surgical approach, even in urgency. In fact, symptomatic carotid stenosis, or particular cases of hemodynamic cerebrovascular events, should be promptly referred to vascular surgeon, since increasing evidences highlighted a benefit from an early artery revascularization. In addition, beyond arrhythmic causes, cardioembolic events due to bacterial endocarditis and atrial myxoma should be quickly diagnosed, possibly in emergency department, because they are a presumptive urgency for heart surgery. In addition to the above-mentioned conditions, in patients suffering from vertebrobasilar TIA or mS, clinicians should keep in mind the Bow Hunter disease, because surgical artery decompression can represent the only suitable treatment in selected cases. CONCLUSIONS: TIA and mS require a multidisciplinary in order to discuss therapeutic options, comparing risks and benefits and determining the best timing for an optimized management.

Search for Lepton Number and Flavor Violation in K

Searches for the lepton number violating K^{+}→π^{-}µ^{+}e^{+} decay and the lepton flavor violating K^{+}→π^{+}µ^{-}e^{+} and π^{0}→µ^{-}e^{+} decays are reported using data collected by the NA62 experiment at CERN in 2017-2018. No evidence for these decays is found and upper limits of the branching ratios are obtained at 90% confidence level: B(K^{+}→π^{-}µ^{+}e^{+})<4.2×10^{-11}, B(K^{+}→π^{+}µ^{-}e^{+})<6.6×10^{-11} and B(π^{0}→µ^{-}e^{+})<3.2×10^{-10}. These results improve by 1 order of magnitude over previous results for these decay modes.

Habitat suitability modelling to predict the distribution of deep coral ecosystems: The case of Linosa Island (southern Mediterranean Sea, Italy).

In areas with limited field data, predictive habitat mapping is a valuable method for elucidating species-environment relationships and enhancing our knowledge of the spatial distribution and complexity of benthic habitats. Species distribution models (SDMs) can be an important tool to support in science-based ecosystem management. The availability of direct observations of mesophotic species, including gorgonians and black corals, during costly surveys is generally limited. Therefore, predicting the distribution of mesophotic species in relation to key physical parameters of the seafloor would help improving conservation strategies in existing and new Marine Protected Areas (MPAs). This study aims to assess the distribution of gorgonians and black corals off Linosa Island, in the Strait of Sicily, a biogeographic boundary area between the western and eastern Mediterranean. The volcanic island of Linosa represents a small, naturally preserved area, with very limited human pressure, hosting rich marine benthic biodiversity on its wide submarine portions. Distribution of the most common coral species off Linosa Island was modelled under an SDM framework, relying on direct observations collected during two research cruises in 2016 and 2017 and a series of terrain parameters acquired through geophysical techniques. We used the so-called "ensemble of small models" approach to calibrate SDMs, which achieved fair-to-excellent results (AUC >0.7). In addition to identifying depth as the primary factor influencing coral distribution, our study also highlighted ruggedness as a significant terrain variable. Specifically, the depth range of 110-230 m emerged as the critical parameter determining habitat suitability for all modelled species, also highlighting peculiar and specie-specific habitat requirements.

Rescue of erythroid development in gene targeted GATA-1- mouse embryonic stem cells.

Development of definitive (fetal liver-derived) red cells is blocked by a targeted mutation in the gene encoding the transcription factor GATA-1. We used in vitro differentiation of GATA-1- mouse embryonic stem (ES) cells to reveal a requirement for GATA-1 during primitive (yolk sac-derived) erythropoiesis and to establish a rescue assay. We show that the block to development includes primitive, as well as definitive, erythroid cells and is complete at the level of globin RNA expression; that the introduction of a normal GATA-1 gene restores developmental potential both in vivo and in vitro; and that efficient rescue is dependent on a putative autoregulatory GATA-motif in the distal promoter. Use of in vitro differentiated ES cells bridges a gap between conventional approaches to gene function in cell lines and analysis of loss of function mutations in the whole animal.

Vitamin A controls epithelial/mesenchymal interactions through Ret expression.

Mutations or rearrangements in the gene encoding the receptor tyrosine kinase RET result in Hirschsprung disease, cancer and renal malformations. The standard model of renal development involves reciprocal signaling between the ureteric bud epithelium, inducing metanephric mesenchyme to differentiate into nephrons, and metanephric mesenchyme, inducing the ureteric bud to grow and branch. RET and GDNF (a RET ligand) are essential mediators of these epithelial-mesenchymal interactions. Vitamin A deficiency has been associated with widespread embryonic abnormalities, including renal malformations. The vitamin A signal is transduced by nuclear retinoic acid receptors (RARs). We previously showed that two RAR genes, Rara and Rarb2, were colocalized in stromal mesenchyme, a third renal cell type, where their deletion led to altered stromal cell patterning, impaired ureteric bud growth and downregulation of Ret in the ureteric bud. Here we demonstrate that forced expression of Ret in mice deficient for both Rara and Rarb2 (Rara(-/-)Rarb2(-/-)) genetically rescues renal development, restoring ureteric bud growth and stromal cell patterning. Our studies indicate the presence of a new reciprocal signaling loop between the ureteric bud epithelium and the stromal mesenchyme, dependent on Ret and vitamin A. In the first part of the loop, vitamin-A-dependent signals secreted by stromal cells control Ret expression in the ureteric bud. In the second part of the loop, ureteric bud signals dependent on Ret control stromal cell patterning.

Phylogeography of the common ragworm Hediste diversicolor (Polychaeta: Nereididae) reveals cryptic diversity and multiple colonization events across its distribution.

Previous studies on the common ragworm Hediste diversicolor (Polychaeta: Nereididae) revealed a marked genetic fragmentation across its distribution and the occurrence of sibling taxa in the Baltic Sea. These results suggested that the phylogeographic patterns of H. diversicolor could reflect interactions between cryptic differentiation and multiple colonization events. This study aims to describe the large-scale genetic structuring of H. diversicolor and to trace the phylogeographic origins of the genetic types described in the Baltic Sea. Samples of H. diversicolor (2 < n < 28) were collected at 16 locations across the NE Atlantic coasts of Europe and Morocco and in the Mediterranean, Black and Caspian Seas and sequenced at two mitochondrial gene fragments (COI and cytb, 345 and 290 bp, respectively). Bayesian analyses revealed deep phylogeographic splits yielding three main clades corresponding to populations (i) from the NE Atlantic coasts (from Germany to Morocco) and from part of the Western Mediterranean, (ii) from the Mediterranean Sea, and (iii) from the Black and Caspian Seas. These clades are further divided in well-supported subclades including populations from different regions of NE Atlantic and Mediterranean (i.e. Portugal/Morocco, Western Mediterranean, Adriatic Sea). The Baltic Sea comprises three sympatric lineages sharing a common evolutionary history with populations from NE Atlantic, Western Mediterranean and Black/Caspian Seas, respectively. Hence, the current patterns of genetic structuring of H. diversicolor appear as the result of allopatric isolation, multiple colonization events and possible adaptation to local environmental conditions.

Impaired mammary gland and lymphoid development caused by inducible expression of Axin in transgenic mice.

Axin is a component of the canonical Wnt pathway that negatively regulates signal transduction by promoting degradation of beta-catenin. To study the role of Axin in development, we developed strains of transgenic mice in which its expression can be manipulated by the administration of doxycycline (Dox). Animals carrying both mouse mammary tumor virus (MMTV)-reverse tetracycline transactivator and tetracycline response element (TRE)2-Axin-green fluorescent protein (GFP) transgenes exhibited Dox-dependent Axin expression and, when induced from birth, displayed abnormalities in the development of mammary glands and lymphoid tissues, both sites in which the MMTV promoter is active. The transgenic mammary glands underwent normal ductal elongation and side branching during sexual maturation and early pregnancy, but failed to develop lobulo-alveoli, resulting in a defect in lactation. Axin attenuated the expression of cyclin D1, a Wnt target that promotes the growth and differentiation of mammary lobulo-alveoli. Increased apoptosis occurred in the mammary epithelia, consistent with the inhibition of a Wnt/cyclin D1 survival signal by Axin. High levels of programmed cell death also occurred in the thymus and spleen. Immature thymocytes underwent massive apoptosis, indicating that the overexpression of Axin blocks the normal development of T lymphocytes. Our data imply that the Axin tumor suppressor controls cell survival, growth, and differentiation through the regulation of an apoptotic signaling pathway.

Domains of axin involved in protein-protein interactions, Wnt pathway inhibition, and intracellular localization.

Axin was identified as a regulator of embryonic axis induction in vertebrates that inhibits the Wnt signal transduction pathway. Epistasis experiments in frog embryos indicated that Axin functioned downstream of glycogen synthase kinase 3beta (GSK3beta) and upstream of beta-catenin, and subsequent studies showed that Axin is part of a complex including these two proteins and adenomatous polyposis coli (APC). Here, we examine the role of different Axin domains in the effects on axis formation and beta-catenin levels. We find that the regulators of G-protein signaling domain (major APC-binding site) and GSK3beta-binding site are required, whereas the COOH-terminal sequences, including a protein phosphatase 2A binding site and the DIX domain, are not essential. Some forms of Axin lacking the beta-catenin binding site can still interact indirectly with beta-catenin and regulate beta-catenin levels and axis formation. Thus in normal embryonic cells, interaction with APC and GSK3beta is critical for the ability of Axin to regulate signaling via beta-catenin. Myc-tagged Axin is localized in a characteristic pattern of intracellular spots as well as at the plasma membrane. NH2-terminal sequences were required for targeting to either of these sites, whereas COOH-terminal sequences increased localization at the spots. Coexpression of hemagglutinin-tagged Dishevelled (Dsh) revealed strong colocalization with Axin, suggesting that Dsh can interact with the Axin/APC/GSK3/beta-catenin complex, and may thus modulate its activity.

Correction of murine beta-thalassemia by gene transfer into the germ line.

A murine beta-thalassemia was corrected by the transfer of cloned beta-globin genes into the mouse germ line. The cloned mouse beta maj-globin gene or the cloned human beta-globin gene was introduced into mice deficient in beta-globin synthesis because of a deletion of the beta maj-globin gene. Both introduced genes produced functional beta-globin chains, leading to a reduction in one case, and elimination in another case, of the anemia and associated abnormalities of the red blood cells.

Evolutionary conservation of repetitive sequence expression in sea urchin egg RNA's.

Cloned repetitive DNA sequences were used to determine the number of homologous RNA transcripts in the eggs of two sea urchin species, Strongylocentrotus purpuratus and S. franciscanus. The eggs of these species contain different amounts of RNA, and their genomes contain different numbers of copies of the cloned repeats. The specific pattern of repetitive sequence representation in the two egg RNA's is nonetheless quantitatively similar. The evolutionary conservation of this pattern suggests the functional importance of repeat sequence expression.

Fibromyalgia comorbidity in primary headaches.

Fibromyalgia syndrome (FMS) is a chronic pain condition of unknown aetiology characterized by diffuse pain and tenderness at tender points. The aim of the study was to assess the prevalence and clinical features of FMS in the different forms of primary headaches, in a tertiary headache centre. Primary headache patients (n = 217) were selected and submitted to the Total Tenderness Score, anxiety and depression scales, Migraine Disability Assessment, allodynia questionnaire, Short Form 36 Health Survey and the Medical Outcomes Study-Sleep Scale. In patients with FMS, the Multidimensional Assessment of Fatigue, the Pain Visual Analog Scale, the Manual Tender Point Survey and the Fibromyalgia Impact Questionnaire were employed. FMS was present in 36.4% of patients and prevailed significantly in tension-type headache and in patients with higher headache frequency. Headache frequency, pericranial muscle tenderness, anxiety and sleep inadequacy were especially associated with FMS comorbidity. In the FMS patients, fatigue and pain at tender points were significantly correlated with headache frequency. FMS seems increasingly prevalent with increased headache frequency, for the facilitation of central sensitization phenomena favoured by anxiety and sleep disturbances.

Videoendoscopic adenoidectomy with microdebrider.

After evaluating approaches proposed, over the last few years, by several Authors, to make the procedure of adenoidectomy safer and more accurate, we have developed a new procedure based on the combined use of a rigid 70 degrees endoscope with a video attachment and a microdebrider, both introduced through the oral cavity. This procedure offers several advantages: an improved field of vision, continuous suction of blood, and extreme precision in removing the adenoid tissue. Compared with current practices which employ the adenotome or curette, it is possible with our approach to remove adenoid tissue in the most important centres: the choanal and tubaric regions. The validity and safety of this videoendoscopic adenoidectomy with microdebrider has been demonstrated in 201 patients.

Androgen insensitivity syndrome.

OBJECTIVE: We provide a review of the literature about the Androgen Insensitivity Syndrome (AIS), its onset and associated developmental anomalies and the genetic alterations causing it. MATERIALS AND METHODS: We searched PubMed with a larger emphasis on the physiology, genetics and current management of AIS. RESULTS: AIS is an X-linked recessive Disorder of Sex Development (DSD). It is caused by mutations of the Androgen Receptor, and their large amount and heterogeneity (missense and nonsense mutations, splicing variants, deletions, and insertions) are responsible for the wide spectrum of possible phenotypes of patients, divided into Partial AIS (PAIS) and Complete AIS (CAIS). Once the clinical and laboratory investigations have laid the foundation for a diagnostic hypothesis, it is important to identify the actual karyotype of the individual and search for the mutation in the Androgen Receptor to diagnose with certainty the syndrome. Alternatively, in the absence of such evidence, the diagnosis should more properly be an AIS-like condition, which we describe as well in our report. CONCLUSIONS: The management of this DSD is based on pharmacotherapies, surgery and psychological support: all of them must be directed to facilitate the patient's life, considering his/her sexual identity.

In vivo demonstration of red cell-endothelial interaction, sickling and altered microvascular response to oxygen in the sickle transgenic mouse.

Intravascular sickling, red cell-endothelium interaction, and altered microvascular responses have been suggested to contribute to the pathophysiology of human sickle cell disease, but have never been demonstrated under in vivo flow. To address this issue, we have examined a transgenic mouse line, alphaHbetaSbetaS-Antilles [betaMDD] which has a combined high (78%) expression of beta S and beta S-Antilles globins. In vivo microcirculatory studies using the cremaster muscle preparation showed adhesion of red cells, restricted to postcapillary venules, in transgenic mice but not in control mice. Electron microscopy revealed distinct contacts between the red cell membrane and the endothelium surface. Some red cells exhibiting sickling were regularly observed in the venular flow. Infusion of transgenic mouse red cells into the ex vivo mesocecum vasculature also showed adhesion of mouse red cells exclusively in venules. Under resting conditions (pO2, 15-20 mmHg), there were no differences in the cremaster microvascular diameters of control and transgenic mice; however, transgenic mice showed a drastic reduction in microvascular red cell velocities (Vrbc) with maximal Vrbc decrease (> 60%) occurring in venules, the sites of red cell adhesion and sickling. Local, transient hyperoxia (pO2, 150 mmHg) resulted in striking differences between control and transgenic mice. In controls, oxygen caused a 69% arteriolar constriction, accompanied by 75% reduction in Vrbc. In contrast, in transgenic mice, hyperoxia resulted in only 8% decrease in the arteriolar diameter and in 68% increase in VrBC; the latter is probably due to an improved flow behavior of red cells as a consequence of unsickling. In summary, the high expression of human sickle hemoglobin in the mouse results not only in intravascular sickling but also red cell-endothelium interaction. The altered microvascular response to oxygen could be secondary to blood rheological changes, although possible intrinsic differences in the endothelial cell/vascular smooth muscle function in the transgenic mouse may also contribute. These sickle transgenic mice could serve as a useful model to investigate vasoocclusive mechanisms, as well as to test potential therapies.

Magnetic resonance evidence of hypoxia in a homozygous alpha-knockout of a transgenic mouse model for sickle cell disease.

All transgenic mouse models for sickle cell disease express residual levels of mouse globins which complicate the interpretation of experimental results. We now report on a mouse expressing high levels of human betaS and 100% human alpha-globin. These mice were created by breeding the alpha-knockout and the mouse beta(major)-deletion to homozygosity in mice expressing human alpha- and betaS-transgenes. These betaS-alpha-knockout mice have accelerated red cell destruction, altered hematological indices, ongoing organ damage, and pathology under ambient conditions which are comparable with those found in alphaH betaS-Ant[betaMDD] mice without introduction of additional mutations which convert betaS into a "super-betaS" such as the doubly mutated betaS-Antilles. This is of particular importance for testing strategies for gene therapy of sickle cell disease. Spin echo magnetic resonance imaging at room air and 100% oxygen demonstrated the presence of blood hypoxia (high levels of deoxygenated hemoglobin) in the liver and kidneys that was absent in control mice. We demonstrate here that transgenic mice can be useful to test new noninvasive diagnostic procedures, since the magnetic resonance imaging technique described here potentially can be applied to patients with sickle cell disease.

Roles of fetal G gamma-globin promoter elements and the adult beta-globin 3' enhancer in the stage-specific expression of globin genes.

The human fetal G gamma-globin and adult beta-globin genes are expressed in a tissue- and developmental stage-specific pattern in transgenic mice: the G gamma gene in embryonic cells and the beta gene in fetal and adult erythroid cells. Several of the cis-acting DNA sequences thought to be responsible for these patterns of expression are located 5' to the G gamma-globin gene and 3' to the beta-globin gene. To further define the locations and functional roles of these elements, we examined the effects of 5' truncations on the expression of the G gamma-globin gene, as well as the ability of G gamma-globin upstream sequences to alter the developmental regulation of a beta-globin gene, as well as the ability of G gamma-globin upstream sequences to alter the developmental regulation of a beta-globin gene. We found that sequences between -201 and -136 are essential for expression of the G gamma-globin gene, whereas those upstream of -201 have little effect on the level or tissue or stage specificity of G gamma-globin expression. The G gamma-globin upstream sequences from -201 to -136 were, furthermore, capable of activating a linked beta-globin gene in embryonic blood cells; however, a G gamma-globin fragment from -383 to -206 was similarly active in this assay, and the complete fragment from -383 to -136 was considerably more active than either of the smaller fragments, suggesting the presence of multiple cis-acting elements for embryonic blood cells. Our data also suggested the possibility of a negative regulatory element between -201 and -136. These results are discussed in relation to several DNA elements in the G gamma-globin upstream region, which have been shown to bind nuclear factors in erythroid cells. Finally, we observed that removal of the beta-globin 3'-flanking sequences, including the 3' enhancer, from the G gamma-globin upstream-beta-globin hybrid gene resulted in a 25-fold reduction in expression in embryonic blood cells. This suggests that the beta-globin 3' enhancer is potentially active at the embryonic stage and thus cannot be solely responsible for the fetal or adult specificity of the beta-globin gene.

Beta-globin enhancers target expression of a heterologous gene to erythroid tissues of transgenic mice.

To examine the role of human beta-globin enhancers in tissue-specific and developmental regulation, a hybrid beta-globin-simian virus 40 gene was analyzed in transgenic mice. A beta-globin DNA fragment containing two previously defined enhancers stimulated transcription from the simian virus 40 promoter in a tissue- and stage-specific pattern similar to that of the normal beta-globin gene. These results help to define the functions of beta-globin regulatory elements and suggest an approach for targeted expression of heterologous genes in erythroid cells in vivo.

Upstream G gamma-globin and downstream beta-globin sequences required for stage-specific expression in transgenic mice.

The human G gamma-globin and beta-globin genes are expressed in erythroid cells at different stages of human development, and previous studies have shown that the two cloned genes are also expressed in a differential stage-specific manner in transgenic mice. The G gamma-globin gene is expressed only in murine embryonic erythroid cells, while the beta-globin gene is active only at the fetal and adult stages. In this study, we analyzed transgenic mice carrying a series of hybrid genes in which different upstream, intragenic, or downstream sequences were contributed by the beta-globin or G gamma-globin gene. We found that hybrid 5'G gamma/3'beta globin genes containing G gamma-globin sequences upstream from the initiation codon were expressed in embryonic erythroid cells at levels similar to those of an intact G gamma-globin transgene. In contrast, beta-globin upstream sequences were insufficient for expression of 5'beta/3'G gamma hybrid globin genes or a beta-globin-metallothionein fusion gene in adult erythroid cells. However, beta-globin downstream sequences, including 212 base pairs of exon III and 1,900 base pairs of 3'-flanking DNA, were able to activate a 5'G gamma/3'beta hybrid globin gene in fetal and adult erythroid cells. These experiments suggest that positive regulatory elements upstream from the G gamma-globin and downstream from the beta-globin gene are involved in the differential expression of the two genes during development.

Identification of an enhancer required for the expression of a mouse major urinary protein gene in the submaxillary gland.

The MUP1.5b gene was previously found to be expressed specifically in the submaxillary gland and at high levels when introduced into mice as a transgene including 4.7 kb of 5'-flanking DNA and 0.3 kb of 3'-flanking DNA. To localize regulatory elements responsible for this tissue-specific pattern of expression, we tested the expression of three additional MUP1.5b transgenes including various amounts of 5'-flanking DNA. These experiments indicated that sequences between -1.85 and -3.46 kb from the transcription initiation site were required for high-level expression in the submaxillary gland. The presence of regulatory elements in this region was also suggested by the detection of a DNase I-hypersensitive site, seen only in submaxillary gland nuclei, at position -2.5 kb upstream from the MUP1.5a gene, a member of the same MUP gene subfamily and virtually identical to the MUP1.5b gene. Further evidence for enhancer activity was provided by the ability of the 1.6-kb DNA fragment including sequences between -1.85 and -3.46 kb to stimulate the expression of an otherwise inactive MUP1.5b-chloramphenicol acetyltransferase fusion gene specifically in the submaxillary gland. The nucleotide sequence of this 1.6-kb DNA fragment was found to be identical for the MUP1.5a and MUP1.5b genes. Together, these results provide the first localization of a cis-acting regulatory sequence involved in the differential tissue-specific expression of the MUP gene family.

Tissue-specific and hormonally regulated expression of a rat alpha 2u globulin gene in transgenic mice.

To investigate the tissue-specific and hormonal regulation of the rat alpha 2u globulin gene family, we introduced one cloned member of the gene family into the mouse germ line and studied its expression in the resulting transgenic mice. Alpha 2u globulingene 207 was microinjected on a 7-kilobase DNA fragment, and four transgenic lines were analyzed. The transgene was expressed at very high levels, specifically in the liver and the preputial gland of adult male mice. The expression in male liver was first detected at puberty, and no expression was detected in female transgenic mice. This pattern of expression is similar to the expression of endogenous alpha 2u globulin genes in the rat but differs from the expression of the homologous mouse major urinary protein (MUP) gene family in that MUPs are synthesized in female liver and not in the male preputial gland. We conclude that these differences between rat alpha 2u globulin and mouse MUP gene expression are due to evolutionary differences in cis-acting regulatory elements. The expression of the alpha 2u globulin transgene in the liver was abolished by castration and fully restored after testosterone replacement. The expression could also be induced in the livers of female mice by treatment with either testosterone or dexamethasone, following ovariectomy and adrenalectomy. Therefore, the cis-acting elements responsible for regulation by these two hormones, as well as those responsible for tissue-specific expression, are closely linked to the alpha 2u globulin gene.