Global gene expression analysis provides insight into local adaptation to geothermal streams in tadpoles of the Andean toad Rhinella spinulosa

Indexación: Web of Science; Scopus.The anuran Rhinella spinulosa is distributed along the Andes Range at altitudes that undergo wide daily and seasonal variation in temperature. One of the populations inhabits geothermal streams, a stable environment that influences life history traits such as the timing of metamorphosis. To investigate whether this population has undergone local adaptation to this unique habitat, we carried out transcriptome analyses in animals from two localities in two developmental stages (prometamorphic and metamorphic) and exposed them to two temperatures (20 and 25 degrees C). RNA-Seq, de novo assembly and annotation defined a transcriptome revealing 194,469 high quality SNPs, with 1,507 genes under positive selection. Comparisons among the experimental conditions yielded 1,593 differentially expressed genes. A bioinformatics search for candidates revealed a total of 70 genes that are highly likely to be implicated in the adaptive response of the population living in a stable environment, compared to those living in an environment with variable temperatures. Most importantly, the population inhabiting the geothermal environment showed decreased transcriptional plasticity and reduced genetic variation compared to its counterpart from the non-stable environment. This analysis will help to advance the understanding of the molecular mechanisms that account for the local adaptation to geothermal streams in anurans.https://www.nature.com/articles/s41598-017-01982-

Intestinal tuberculosis in a child living in a country with a low incidence of tuberculosis: a case report

Background: Relatively common in adults, intestinal tuberculosis is considered rare in children and adolescents. The protean manifestations of intestinal tuberculosis mean that the diagnosis is often delayed (sometimes even for years), thus leading to increased mortality and unnecessary surgery. The main diagnostic dilemma is to differentiate intestinal tuberculosis and Crohn’s disease because a misdiagnosis can have dramatic consequences. Case presentation: A 13-year-old Caucasian, Italian female adolescent attended the Emergency Department complaining of abdominal pain, a fever of up to 38°C, night sweats, diarrhea with blood in stool, and a weight loss of about three kilograms over the previous two months. Physical examination revealed a marked skin pallor and considerable abdominal distension with relevant discomfort in all the abdominal quadrant. Laboratory tests revealed a decreased white blood cell count with anemia and increased C-reactive protein levels. The Mantoux tuberculin skin test was negative. A chest X-ray and an abdominal ultrasonography did not reveal any significant findings. The patient underwent colonoscopy that showed diffuse mucosal congestion and significant blood loss, and laparatomy showed small bowel and colon loops with a whitish appearance. A biopsy of the ileal mucosa revealed inflammation with noncaseating granulomas possibly due to bacterial infection. Given the suspicion of an opportunistic bacterial infection in a child with chronic inflammatory bowel disease (possibly Crohn’s disease), treatment with a third-generation cephalosporin was started. However, the abdominal pain, fever and poor general condition persisted and so, after 11 days, the patient underwent total body computed tomography and magnetic resonance imaging of the brain. On the basis of the radiological findings, miliary tuberculosis was suspected and bronchoscopy was performed and resulted positive for Mycobacterium tuberculosis. Miliary tuberculosis was confirmed and an effective treatment with four drugs was started. Conclusion: This case shows that the manifestations of intestinal tuberculosis can be very difficult to diagnose and mimic those of Chron’s disease. Total body computed tomography and laparotomy with an intestinal biopsy for the detection of Mycobacterium tuberculosis are the means of avoid the risks of a misdiagnosis in children with unexplained chronic abdominal problems

Case Report: Atypical psychotic onset of type I Arnold-Chiari malformation

Introduction: We report a case of type I Arnold-Chiari malformation that is very peculiar because of its particular onset especially characterized by psychiatric symptoms. These symptoms were so prevailing that, for fifteen years, they masked the neurological aspects and the patient was treated with high doses of psychotropic drugs without any benefit. If the Arnold-Chiari malformation had been diagnosed before the development of severe hydro-syringomyelia, the patient could have underwent decompressive neurosurgery which may have improved her quality of life. It is worthwhile to highlight that psychotic symptoms may be caused by this congenital malformation, that typically has an aspecific onset. Therefore it\u2019s important to consider an eventual organic etiology while challenging a resistant clinical picture with unusual presentation. Case description: A 51-year-old woman reported neurological symptoms consisting of headaches, blurred vision, diplopia, tinnitus, vertigo and psychiatric symptoms including obsessive ideas about the fear of killing her son, auditory and visual pseudo-hallucinations. The symptoms had developed suddenly at the age of 35 years and persisted thereafter. She underwent multiple hospitalizations in psychiatric units and was treated with a variety of psychopharmacological approaches without substantial improvement. We performed a brain MRI that identified a type I Arnold-Chiari malformation. We assessed psychiatric symptoms using the Structured Clinical Interview for DSM IV Axis I Disorders, the Brief Psychiatric Rating Scale, and the Yale-Brown Obsessive-Compulsive Scale. A tailored psychopharmacological therapy led to a partial improvement in mood and anxiety but not in hallucinations. Discussion: We want to highlight how important is, in everyday psychiatric clinical practice, not to focus only on psychiatric aspects but consider the patient globally, because in this case psychiatric problems were the onset presentation of a rare neurological syndrome

Electron-Beam-Induced Grafting Of Chitosan Onto HDPE/ATZ Composites for Biomedical Applications

HDPE and HDPE/ATZ surfaces were functionalised with chitosan Via electron-beam irradiation technique in order to prepare materials suitable for biomedical purposes. ATR–FTIR and wettability measurements were employed for monitoring the surface changes after both irradiation and chitosan grafting reaction. The presence of ATZ influenced both the EB irradiation process and the surface functionalisation. Mechanical properties of irradiated materials were not remarkably affected by irradiation processing. Biological assays indicated that electrostatic interactions between the negative charges of the surface of cell membranes and the –NH3+ sites on chitosan chains promoted cell adhesion, while some oxidized species produced during the irradiation process were thought to cause a detrimental effect on the cell Viability

The microanalysis of iron and sulphur oxidation states in silicate glass - Understanding the effects of beam damage

Quantifying the oxidation state of multivalent elements in silicate melts (e.g., Fe²⁺ versus Fe³⁺ or S²⁻ versus S⁶⁺) is fundamental for constraining oxygen fugacity. Oxygen fugacity is a key thermodynamic parameter in understanding melt chemical history from the Earth's mantle through the crust to the surface. To make these measurements, analyses are typically performed on small (<100 µm diameter) regions of quenched volcanic melt (now silicate glass) forming the matrix between crystals or as trapped inclusions. Such small volumes require microanalysis, with multiple techniques often applied to the same area of glass to extract the full range of information that will shed light on volcanic and magmatic processes. This can be problematic as silicate glasses are often unstable under the electron and photon beams used for this range of analyses. It is therefore important to understand any compositional and structural changes induced within the silicate glass during analysis, not only to ensure accurate measurements (and interpretations), but also that subsequent analyses are not compromised. Here, we review techniques commonly used for measuring the Fe and S oxidation state in silicate glass and explain how silicate glass of different compositions responds to electron and photon beam irradiation