RN7SK small nuclear RNA controls bidirectional transcription of highly expressed gene pairs in skin.

Funder: Wellcome TrustFunder: Medical Research CouncilPausing of RNA polymerase II (Pol II) close to promoters is a common regulatory step in RNA synthesis, and is coordinated by a ribonucleoprotein complex scaffolded by the noncoding RNA RN7SK. The function of RN7SK-regulated gene transcription in adult tissue homoeostasis is currently unknown. Here, we deplete RN7SK during mouse and human epidermal stem cell differentiation. Unexpectedly, loss of this small nuclear RNA specifically reduces transcription of numerous cell cycle regulators leading to cell cycle exit and differentiation. Mechanistically, we show that RN7SK is required for efficient transcription of highly expressed gene pairs with bidirectional promoters, which in the epidermis co-regulated cell cycle and chromosome organization. The reduction in transcription involves impaired splicing and RNA decay, but occurs in the absence of chromatin remodelling at promoters and putative enhancers. Thus, RN7SK is directly required for efficient Pol II transcription of highly transcribed bidirectional gene pairs, and thereby exerts tissue-specific functions, such as maintaining a cycling cell population in the epidermis

Is the corpus callosum degeneration a predictor of long-term disability in Multiple Sclerosis patients?

Axonal injury and loss of white matter has been well documented in corpus callosum (CC) of patients with multiple sclerosis (MS), an inflammatory demyelinating disorder of the of Central Nervous System (CNS). The CC is the largest compact white matter fiber bundle of the brain connecting the two cerebral hemispheres. It seems that CC continue to mature structurally from infancy to adulthood (Muetzel RL, 2008). The topographical organization of its fibers allows the association of its abnormalities with those of specific cortical regions. It is one of the few white matter tracts that can be adequately evaluated by conventional Magnetic Resonance Imaging (MRI), having sharply demarcated two-dimensional limits on a mid-saggital T1W imaging (Fiqueira FF, 2007). So, as a consequence of these anatomic characteristics, it is reasonable to assume that CC morphometrics might be used as a possible marker for the analysis of its integrity. Conventional and non-conventional MRI techniques have been used to characterize pathological damages of the CC; for instance, diffusion tensor imaging (DTI) can show white matter changes undetected by conventional MRI (Bester M, 2008). We carried out a review focusing our interest on the diagnostic efficacy of MRI to predict MS disability. PubMed search engine was used to select manuscripts with predefined search terms: “corpus callosum”, “multiple sclerosis”, “disability” and “magnetic resonance imaging”. Only manuscripts in English language, published from January 2003 to January 2013, were selected. Abstracts and unpublished studies were excluded. References of all relevant retrieved articles, of review articles, were also evaluated manually in order to find additional articles. For data extraction an electronic form was prepared. The findings of the review suggest that CC atrophy is a more sensitive marker of disease activity than the global atrophy measures, predicting clinically definite multiple sclerosis (CDMS)conversion as early as 6 months of clinically isolated syndrome (CIS) (Kalincik T, 2012). Furthermore, the occurrence or growth of lesions over the first year in the splenium of corpus callosum, together with the cerebellum and the thalamus, was associated with cognitive worsening at year 5. CC atrophy seems to be a simple and an accurate predictor of disability, mostly for secondary progressive MS (Fiqueira FF, 2007), and it seems helpful for routine clinical activities (Vaneckova M, 2012)

Neuroanatomy, the Achille's heel of medical students. A systematic analysis of educational strategies for the teaching of neuroanatomy

Neuroanatomy has been deemed crucial for clinical neurosciences. It has been one of the most challenging parts of the anatomical curriculum and is one of the causes of “neurophobia,” whose main implication is a negative influence on the choice of neurology in the near future. In the last decades, several educational strategies have been identified to improve the skills of students and to promote a deep learning. The aim of this study was to systematically review the literature to identify the most effective method/s to teach human neuroanatomy. The search was restricted to publications written in English language and to articles describing teaching tools in undergraduate medical courses from January 2006 through December 2017. The primary outcome was the observation of improvement of anatomical knowledge in undergraduate medical students. Secondary outcomes were the amelioration of long‐term retention knowledge and the grade of satisfaction of students. Among 18 selected studies, 44.4% have used three‐dimensional (3D) teaching tools, 16.6% near peer teaching tool, 5.55% flipped classroom tool, 5.55% applied neuroanatomy elective course, 5.55% equivalence‐based instruction‐rote learning, 5.55% mobile augmented reality, 5.55% inquiry‐based clinical case, 5.55% cadaver dissection, and 5.55% Twitter. The high in‐between study heterogeneity was the main issue to identify the most helpful teaching tool to improve neuroanatomical knowledge among medical students. Data from this study suggest that a combination of multiple pedagogical resources seems to be the more advantageous for teaching neuroanatomy

PROGNOSTIC IMPACT OF IMMUNOHISTOCHEMICAL P53 EXPRESSION IN BONE MARROW BIOPSY IN HIGHER RISK MDS: A PILOT STUDY

Background and objectives: Mutations of the TP53 gene have an unfavorable prognosis in Myelodysplastic Syndromes (MDS). The product of the TP53gene is the p53 protein. Most of TP53mutations entail the accumulation of the protein in the nucleus of tumor cells. The immunohistochemical (IHC) staining for p53 can be a surrogate suggesting a mutational status and, if overexpressed, seems to be of prognostic value by itself. The best prognostic cut-off value of overexpression is controversial. The aim of this pilot study is to investigate about the correct value from a homogenous group of patients with higher IPSS-R risk MDS. Methods: In sixty consecutive patients diagnosed with MDS and categorized as IPSS-R risk “intermediate”, “high” and “very high”, the bone marrow biopsies performed at the diagnosis were retrospectively re-examined for IHC p53 expression. The result of p53 expression was subsequently related to survival.  Results: A worst overall survival was observed both in patients whose IHC p53 expression was ≥5% and ≥ 10% compared to the patients with a p53 expression respectively below 5% (p= 0.0063) or 10% (p=0.0038).  Conclusions: The ICH p53 expression in bone marrow biopsy in higher risk MDS was confirmed to have prognostic value.  These results indicate more than 10% expression as the best cut off value

Ultrasound and autoptic diagnosis of asphyxiating thoracic dysplasia

Background. The skeletal system develops from mesoderm. In most bones (e.g., the long bones), ossification is preceded by cartilage (endochondral ossification). In other cases, such as flat bones, ossification develops directly in the mesenchyme without cartilage formation (intramembranous ossification). Skeletal dysplasias are a heterogeneous group of more disorders associated with developmental abnormalities of bone and cartilage. The modes of transmission are similar: autosomal dominant and recessive and X-linked dominant and recessive. Despite the potential advantages of 3-dimensional ultrasound (3D-US), antenatal diagnosis of skeletal dysplasia is difficult, given the large variety and complexity of these disorders: their phenotypes are variables and their features are overlapping. We present a case report of a woman with prenatal diagnosis of skeletal thoracic dysplasia, confirmed by postnatal radiography and fetal autopsy. Case report. A 26-year-old woman, primigravida, was referred for routine ultrasonic examination during her second trimester of pregnancy. Ultrasonography (USG) showed a single live foetus of a gestational age of 20+3 weeks; biparietal diameter and head circumference were adequate for the week of gestation. There was a polyhydramnios. The fetal thorax was extremely narrow. The thoracic circumference (TC) measured 100 mm (< 5th percentile), the abdominal circumference (AC) measured 157 mm (50th percentile), and the TC/AC ratio was 0.64 (normal range: 0.77–1.01). The long-bone lengths measured < 5th percentile, especially the proximal part of the upper limbs. Ultrasound scans of fetal abdomen revealed bilateral slight increase in the size of kidneys. There were no neural tube defects, and the fetal stomach and urinary bladder were normal. Fetal echocardiography revealed mild ventricular septal defect with good hemodynamic effect. Based on these findings, the diagnosis postulated as possible was asphyxiating thorax dysplasia (ATD). After genetic counseling, the patient decided for an elective termination of the pregnancy. A stillborn male fetus was delivered with a weight of 470 g. Infantogram and gross autopsy findings (narrow thorax, short upper limb bones, poor definition of pyramids of kidneys) supported the diagnosis made. Conclusion. Although skeletal anomalies are difficult to diagnose antenatally, a detailed scan of fetal anatomy between 20 and 32 gestational weeks exclude majority of major skeletal dysplasias. Termination of pregnancy is indicated and must be followed by genetic counseling for recurrence risk

Rhinosinusal polyposis and metals: morphological aspects

Metals have strong toxic effects in humans and can act as immunoregulatory factors. The purpose of our study was to determine whether the concentrations of metals are associated with the clinical course of nasal polyposis (NP). We measured the concentrations of 10 metals (Zn, Mn, Se, Fe, Cr, Ni, Pb, Al, Cd, and Cu) in 58 patients with NP, and 29 controls with a healthy nasal mucosa. We used electron microscopy to compare the ultrastructural features of the nasal mucosa between NP patients and healthy controls. Concentrations of metals in nasal polyps and healthy mucosa were determined by mass spectrometry. Transmission electron microscopic (TEM) and scanning electron microscopic (SEM) images of the nasal mucosa were obtained. The mean tissue concentrations of all 10 metals were significantly lower in NP patients than in healthy controls (P < 0.001). Tissue concentrations of each metal were lower in stages III and IV NP than in stages I and II NP, although the differences were not statistically significant. TEM and SEM revealed changes in the mucosal ultrastructure in NP with progression from isolated polyposis (stages I and II) to massive polyposis (stages III and IV) with progressive fibrosis, devascularisation, and inflammation. Tissue concentrations of metals were lower in NP patients than in healthy controls, and this was particularly evident in massive polyposis. Polyp structure could contribute to the lower concentrations of metals by exposing the tissue to increased oxidative stress

Observation of channeling for 6500 GeV/c protons in the crystal assisted collimation setup for LHC

Two high-accuracy goniometers equipped with two bent silicon crystals were installed in the betatron cleaning insertion of the CERN Large Hadron Collider (LHC) during its long shutdown. First beam tests were recently performed at the LHC with 450 GeV/c and 6500 GeV/c stored proton beams to investigate the feasibility of beam halo collimation assisted by bent crystals. For the first time channeling of 6500 GeV/c protons was observed in a particle accelerator. A strong reduction of beam losses due to nuclear inelastic interactions in the aligned crystal in comparison with its amorphous orientation was detected. The loss reduction value was about 24. Thus, the results show that deflection of particles by a bent crystal due to channeling is effective for this record particle energy.peer-reviewe

Cadmium modifies the cell cycle and apoptotic profiles of human breast cancer cells treated with 5-fluorouracil

Industrialisation, the proximity of factories to cities, and human work activities have led to a disproportionate use of substances containing heavy metals, such as cadmium (Cd), which may have deleterious effects on human health. Carcinogenic effects of Cd and its relationship with breast cancer, among other tumours, have been reported. 5-Fluorouracil (5-FU) is a fluoropyrimidine anticancer drug used to treat solid tumours of the colon, breast, stomach, liver, and pancreas. The purpose of this work was to study the effects of Cd on cell cycle, apoptosis, and gene and protein expression in MCF-7 breast cancer cells treated with 5-FU. Cd altered the cell cycle profile, and its effects were greater when used either alone or in combination with 5-FU compared with 5-FU alone. Cd significantly suppressed apoptosis of MCF-7 cells pre-treated with 5-FU. Regarding gene and protein expression, bcl2 expression was mainly upregulated by all treatments involving Cd. The expression of caspase 8 and caspase 9 was decreased by most of the treatments and at all times evaluated. C-myc expression was increased by all treatments involving Cd, especially 5-FU plus Cd at the half time of treatment. Cd plus 5-FU decreased cyclin D1 and increased cyclin A1 expression. In conclusion, our results indicate that exposure to Cd blocks the anticancer effects of 5-FU in MCF-7 cells. These results could have important clinical implications in patients treated with 5-FU-based therapies and who are exposed to high levels of Cd

Interleukin 1β triggers synaptic and memory deficits in Herpes simplex virus type-1-infected mice by downregulating the expression of synaptic plasticity-related genes via the epigenetic MeCP2/HDAC4 complex

Extensive research provides evidence that neuroinflammation underlies numerous brain disorders. However, the molecular mechanisms by which inflammatory mediators determine synaptic and cognitive dysfunction occurring in neurodegenerative diseases (e.g., Alzheimer's disease) are far from being fully understood. Here we investigated the role of interleukin 1 beta (IL-1 beta), and the molecular cascade downstream the activation of its receptor, to the synaptic dysfunction occurring in the mouse model of multiple Herpes simplex virus type-1 (HSV-1) reactivations within the brain. These mice are characterized by neuroinflammation and memory deficits associated with a progressive accumulation of neurodegenerative hallmarks (e.g., amyloid-beta protein and tau hyperphosphorylation). Here we show that mice undergone two HSV-1 reactivations in the brain exhibited increased levels of IL-1 beta along with significant alterations of: (1) cognitive performances; (2) hippocampal long-term potentiation; (3) expression synaptic-related genes and pre- and post-synaptic proteins; (4) dendritic spine density and morphology. These effects correlated with activation of the epigenetic repressor MeCP2 that, in association with HDAC4, affected the expression of synaptic plasticity-related genes. Specifically, in response to HSV-1 infection, HDAC4 accumulated in the nucleus and promoted MeCP2 SUMOylation that is a post-translational modification critically affecting the repressive activity of MeCP2. The blockade of IL-1 receptors by the specific antagonist Anakinra prevented the MeCP2 increase and the consequent downregulation of gene expression along with rescuing structural and functional indices of neurodegeneration. Collectively, our findings provide novel mechanistic evidence on the role played by HSV-1-activated IL-1 beta signaling pathways in synaptic deficits leading to cognitive impairment

Morphological findings in malformed fetuses with normal karyotype

In our Department morphological findings on fetuses from therapeutic interruption of pregnancy or spontaneous abortion are performed since ten years in order to correlate the ultrasound and/or chromosomic diagnosis with a real presence of malformations. The fetopathologic examination generally agrees with the chromosomal diagnosis, while in several cases it is possible to find malformations also in presence of a normal karyotype (Gitz, 2011). In our experience over the past 5 years we have found that 17 fetuses with a normal karyotype showed different heterogeneous ultrasound malformations. Only in 2 cases the fetuses died in uterus (17th and 22nd weeks of gestation), the other cases, aged between 14th and 23rd weeks of gestation, went from voluntary abortions. In 7 cases the karyotype was defined by amniocentesis while in the remaining 10 was determined by fetal fibroblasts culture; in only 30% of the observed cases the couple had carried out a genetic evaluation. External malformations were present in 16 fetuses, often related to the face (such as micrognathia, low-set of ears, flattened nasal bridge, cleft lip) or limb (short, curved, stubby) of spine (spina bifida) or genitalia (hypospadias). Malformations of internal organs were present in 10 cases, often affecting the cardiovascular system (complex heart defects and abnormal origin of the greath vessels), and nervous system (meningocele, agenesia of the corpus callosum, ventricular dilatation and Arnold-Chiari malformation); less frequent were malformations of other systems (digestive, respiratory and urinary). There was a single case of situs viscerum inversus associated with complex cardiac malformations and atresia of the bucco-pharyngeal membrane. These results indicate that the fetal morphological study is useful not only to confirm but often to supplement and complete the ultrasound data. Moreover genetic evaluation, utilizing fetopatholgical study, may have an important role in defining the diagnostic and clinical procedure, especially in relapses with malformed fetus and normal karyotype