Telomeric repeat-containing RNA is dysregulated in acute myeloid leukemia.

TERRA (telomeric repeat-containing RNA) is a class of long noncoding RNAs transcribed from subtelomeric and telomeric regions. TERRA binds to the subtelomeric and telomeric DNA-forming R-loops (DNA-RNA hybrids), which are involved in telomere maintenance and telomerase function, but the role of TERRA in human cells is not well characterized. Here, we comprehensively investigated for the first time TERRA expression in primary human hematopoietic cells from an exploratory cohort of patients with acute myeloid leukemia (AML), patients with acute lymphoblastic leukemia (ALL), patients with telomere biology disorder (TBD), and healthy subjects. TERRA expression was repressed in primary human hematopoietic cells, including healthy donors, patients with ALL, and patients with TBD, irrespective of their telomere length, except for AML. A second cohort comprising 88 patients with AML showed that TERRA was overexpressed in an AML subgroup also characterized by higher R-loop formation, low TERT and RNAseH2 expression, and a paucity of somatic splicing factor mutations. Telomere length did not correlate with TERRA expression levels. To assess the role of TERRA R-loops in AML, we induced R-loop depletion by increasing RNAseH1 expression in 2 AML cell lines. Decreased TERRA R-loops in AML cell lines resulted in increased chemosensitivity to cytarabine. Our findings indicate that TERRA is uniformly repressed in primary human hematopoietic cells but abnormally expressed in an AML subset with low telomerase.

Pressure-sensitive platform based on multiplexed in-series macro-bend optical fiber sensors.

This work shows a pressure-sensitive platform instrumented with a set of five in-series macro-bend optical fiber sensors. The structure of 20×20cm is divided into sixteen 5×5cm sensing cells. Sensing is based on the wavelength-dependent intensity changes in the array transmission visible spectrum, which carries information about the pressure acting on the structure. Data analysis uses principal component analysis to reduce spectral data to 12 principal components that explain 99% of the data variance and k-nearest neighbors classification and support vector regression methods. The capability of pressure detection with fewer sensors than the number of monitored cells was demonstrated with an accuracy of 94% for predicting the pressure location and a mean absolute error of 0.31 kPa within 3.74-9.98 kPa range.

New derivative of trans-dehydrocrotonin isolated from Croton cajucara shows reduced cytotoxic and genotoxic effects in hepatocellular carcinoma (HepG2) cell line.

The Croton cajucara (Euphorbiales, Euphorbiaceae) plant occurs widely in the Amazon region, where its leaves and stem bark are consumed by the population to treat several diseases. The secondary metabolite trans-dehydrocrotonin (DCTN) is mainly accountable for the biological activities of this plant. However, prolonged consumption is associated with hepatotoxic effects due to the furan ring present in the molecule. This group is responsible for toxicity reactions in other drugs. In this work, we inserted a COOH group into the molecule to prevent the formation of toxic intermediates. We assessed the cytotoxicity and genotoxicity of both molecules on HepG2 cells. Results showed that the new derivative (CCTN) is less cytotoxic and did not reduce cell viability at any concentration tested. Genotoxicity was also reduced as assessed by the comet and micronucleus assay. Therefore, the new derivative appears to be promising and additional tests should be performed to evaluate its therapeutic activities.

Two new surprising species of leaf-litter toad of the Rhinella margaritifera species group (Anura: Bufonidae) from the Peruvian Amazon, LoretoPeru.

We describe two new species of Rhinella (Anura: Bufonidae) from the department of Loreto, Peru. We integrate morphological and phylogenetic analyses to provide evidence of new species. R. angeli sp. nov. is diagnosable from all congeners by its pronounced fleshy proboscis and R. unapensis sp. nov. by the small size (mean snout-vent length=37.7 4.1 mm) of adult males, snout pointed in dorsal view, nearly acute in lateral view, and small bony protrusion at the angle of jaws among other characters. The two species are allopatric, where the first species is known to be associated inhabits upland (=terra firme) forests, while the second white sand forests (=varillales) around Iquitos city. The two new species represent the 20th and 21st species of the Rhinella margaritifera species group.

Defective hematopoietic differentiation of immune aplastic anemia patient-derived iPSCs.

In acquired immune aplastic anemia (AA), pathogenic cytotoxic Th1 cells are activated and expanded, driving an immune response against the hematopoietic stem and progenitor cells (HSPCs) that provokes cell depletion and causes bone marrow failure. However, additional HSPC defects may contribute to hematopoietic failure, reflecting on disease outcomes and response to immunosuppression. Here we derived induced pluripotent stem cells (iPSCs) from peripheral blood (PB) erythroblasts obtained from patients diagnosed with immune AA using non-integrating plasmids to model the disease. Erythroblasts were harvested after hematologic response to immunosuppression was achieved. Patients were screened for germline pathogenic variants in bone marrow failure-related genes and no variant was identified. Reprogramming was equally successful for erythroblasts collected from the three immune AA patients and the three healthy subjects. However, the hematopoietic differentiation potential of AA-iPSCs was significantly reduced both quantitatively and qualitatively as compared to healthy-iPSCs, reliably recapitulating disease: differentiation appeared to be more severely affected in cells from the two patients with partial response as compared to the one patient with complete response. Telomere elongation and the telomerase machinery were preserved during reprogramming and differentiation in all AA-iPSCs. Our results indicate that iPSCs are a reliable platform to model immune AA and recapitulate clinical phenotypes. We propose that the immune attack may cause specific epigenetic changes in the HSPCs that limit adequate proliferation and differentiation.

Personalized upper limb orthosis necessitates variety of tools during the development process: hemiplegic child case study.

PURPOSE: A design methodology for the creation of an upper-limb dynamic orthosis for children was developed in this article. For a non-negligible numerous of cases, orthoses are abandoned for many reasons: they are expensive, heavy, complicated to use, uncomfortable, non-customized, and so on. Three-dimensional (3D) printing technologies are a way to answer a lot of these issues. Moreover, virtual reality and serious games are more and more used in rehabilitation for users' motivation and sometimes for disability evaluation. MATERIALS AND METHODS: Microsoft Kinect and Leap Motion technologies combined with games were manipulated to identify the user abilities. Meetings with specialists were made to develop the technical specifications of the orthosis. 3D printer was used with an iterative process for the development of the personalized orthosis. It allowed to progressively focus on the final product thanks to successive prototypes. A Polylactic Acid material was validated with specialists to verify the product reliability. RESULTS: Thirteen prototypes were printed. Technical adjustments were done regarding the 3D printer technology and the molding procedure during the first development cycles. User and physiotherapists were more involved during the 4 final cycles. CONCLUSIONS: A combination of design process, technological tools and technical material allowed a 67 g dynamic upper-limb orthosis to be produced, satisfying all technical specifications.Implications for rehabilitationAn iterative design process allows to quickly manufacture and test numerous physical prototypes with design team and final user.Moulding material can be used with 3D printer technologies for facilitating the personalization of the orthosis.Virtual reality and serious game are used as engineering tools to clarify the patient's abilities and needs.

A new species of the Rhinella margaritifera (Laurenti 1768) species group (Anura, Bufonidae) from southern Brazilian Amazonia.

Neotropical toads from the Rhinella margaritifera species group have been considered a taxonomic puzzle for a long time. Because of the high morphological similarity and an unknown number of undescribed taxa among the species of this group, we did an extensive search for character distribution within all nominal taxa. Herein we describe Rhinella parecis sp. nov. a new species from Southern Brazilian Amazon. We provide a morphological diagnosis, morphometric comparisons with similar species, and a molecular phylogenetic hypothesis on the relationships of the new species. Rhinella parecis sp. nov. is assigned to the R. margaritifera group and differs from others species by snout-vent length ranging 40.7-53.5 mm in males (n=12) and 44.9-54.8 mm in females (n=4), snout rounded in dorsal view, acute with fleshy ridge extending to tip of snout in lateral view, canthal and pre-orbital crests absent, supra-orbital, parietal and supra-tympanic crests present and low, dorsolateral row of tubercles present, bony protrusion at the angle of jaws absent, tympanum evident, vertebral apophyses absent and toes half-webbed. The new species is the 20th species associated to the R. margaritifera group distributed in the Chapada dos Parecis, a probable center of endemism in states of Rondônia and Mato Grosso, Brazil.

The Amazonian Red Side-Necked Turtle Rhinemys rufipes (Spix, 1824) (Testudines, Chelidae) Has a GSD Sex-Determining Mechanism with an Ancient XY Sex Microchromosome System.

The Amazonian red side-necked turtle Rhynemis rufipes is an endemic Amazonian Chelidae species that occurs in small streams throughout Colombia and Brazil river basins. Little is known about various biological aspects of this species, including its sex determination strategies. Among chelids, the greatest karyotype diversity is found in the Neotropical species, with several 2n configurations, including cases of triploidy. Here, we investigate the karyotype of Rhinemys rufipes by applying combined conventional and molecular cytogenetic procedures. This allowed us to discover a genetic sex-determining mechanism that shares an ancestral micro XY sex chromosome system. This ancient micro XY system recruited distinct repeat motifs before it diverged from several South America and Australasian species. We propose that such a system dates back to the earliest lineages of the chelid species before the split of South America and Australasian lineages.

Rediscovery of Osteocephalus vilarsi (Anura: Hylidae): an overlooked but widespread Amazonian spiny-backed treefrog.

Osteocephalus vilarsi (Melin, 1941) is an Amazonian treefrog species known for over 75 years from its holotype only. Due to a lack of published data on its morphological diagnostic characters and their variations, as well as the absence of molecular, acoustic and ecological data supporting its identity, a highly dynamic taxonomic history has led this species to be confused and even synonymised with other Osteocephalus species from distinct species groups. The molecular phylogenetic relationships of O. vilarsi were investigated based on recently collected specimens from eight Northwestern Brazilian localities in the state of Amazonas, leading to its removal from the Osteocephalus taurinus species group and placement in the Osteocephalus planiceps species group. Furthermore, detailed data on morphology and colour variation are provided, as well as advertisement call and tadpole descriptions. Finally, the currently known geographic range of O. vilarsi is considerably extended, first data on the natural history of the species are provided, and the possible ecological preference of O. vilarsi for Amazonian white-sand forests is discussed.

Redescription of the Amazonian tiny tree toad Amazophrynella minuta (Melin, 1941) (Anura: Bufonidae) from its type locality.

The description of Amazophrynella minuta was published in 1941 by the Swedish naturalist Douglas Melin based on material from Taracuá (Amazonas state, Brazil). This description was very brief and based on the morphology of few specimens with diagnostic characters and color variation not well defined. Moreover, the type series is currently in poor state of conservation. Consequently, taxonomic ambiguity surrounds the nominal taxon A. minuta, which hampers the description of many unnamed congeneric species. Herein, we redescribe A. minuta based on recently collected specimens from the type locality, designate a lectotype, formulate a new diagnosis, provide patterns of morphological variation, measurements and body proportions.

Description of the advertisement calls of four species of Amazophrynella (Anura:Bufonidae).

Amazophrynella comprises 11 small bufonid species with a pan-Amazonian distribution (Fouquet et al. 2012a, b; Rojas et al. 2016, Rojas et al. 2018). All species inhabit the forest leaf litter, breed in seasonal puddles and are diurnally and nocturnally active (Fouquet et al. 2012b; Rojas et al. 2014; 2015; 2016). Until now only one nominal species, A. javierbustamantei, and two putative lineages-A. moisesii (Rio Yuyapichis, Peru) and A. siona (Santa Cecilia, Ecuador)-had their advertisement calls formally described (Duellman 1978; Schlüter 1981; Rojas et al. 2016). Herein, we described for the first time the advertisement calls from additional four species of Amazophrynella.

A Pan-Amazonian species delimitation: high species diversity within the genus Amazophrynella (Anura: Bufonidae).

Amphibians are probably the most vulnerable group to climate change and climate-change associate diseases. This ongoing biodiversity crisis makes it thus imperative to improve the taxonomy of anurans in biodiverse but understudied areas such as Amazonia. In this study, we applied robust integrative taxonomic methods combining genetic (mitochondrial 16S, 12S and COI genes), morphological and environmental data to delimit species of the genus Amazophrynella (Anura: Bufonidae) sampled from throughout their pan-Amazonian distribution. Our study confirms the hypothesis that the species diversity of the genus is grossly underestimated. Our analyses suggest the existence of eighteen linages of which seven are nominal species, three Deep Conspecific Lineages, one Unconfirmed Candidate Species, three Uncategorized Lineages, and four Confirmed Candidate Species and described herein. We also propose a phylogenetic hypothesis for the genus and discuss its implications for historical biogeography of this Amazonian group.

Integrative overview of the herpetofauna from Serra da Mocidade, a granitic mountain range in northern Brazil.

The Brazilian mountain ranges from the Guiana Shield highlands are largely unexplored, with an understudied herpetofauna. Here the amphibian and reptile species diversity of the remote Serra da Mocidade mountain range, located in extreme northern Brazil, is reported upon, and biogeographical affinities and taxonomic highlights are discussed. A 22-days expedition to this mountain range was undertaken during which specimens were sampled at four distinct altitudinal levels (600, 960, 1,060 and 1,365 m above sea level) using six complementary methods. Specimens were identified through an integrated approach that considered morphological, bioacoustical, and molecular analyses. Fifty-one species (23 amphibians and 28 reptiles) were found, a comparable richness to other mountain ranges in the region. The recorded assemblage showed a mixed compositional influence from assemblages typical of other mountain ranges and lowland forest habitats in the region. Most of the taxa occupying the Serra da Mocidade mountain range are typical of the Guiana Shield or widely distributed in the Amazon. Extensions of known distribution ranges and candidate undescribed taxa are also recorded. This is the first herpetofaunal expedition that accessed the higher altitudinal levels of this mountain range, contributing to the basic knowledge of these groups in remote areas.

The tadpole of Amazophrynella manaos Rojas, Carvalho, Gordo, Ávila, Farias and Hrbek, 2014 (Anura, Bufonidae) from the type locality and adjacent regions at Central Amazonia, Brazil.

The genus Amazophrynella, as currently recognized (Fouquet et al. 2012a, b), is represented by four nominal species (Frost 2014; Rojas et al. 2014) but the tadpoles of only one species, Amazophrynella minuta (Melin) from Ecuador, have been described (Duellman & Lynch 1969; Duellman 1978). Amazophrynella manaos Rojas, Carvalho, Gordo, Ávila, Farias and Hrbek, 2014 occurs in the leaf litter of terra firme forest in the southwestern part of the Brazilian Guiana region (Rojas et al. 2014). The tadpole of this species was briefly described in diagrammatic drawings by Hero (1990) as Dendrophryniscus minutus. Herein, we provide a detailed description of this tadpole based on individuals at 12 stages of development collected in five different sites, including the type locality, at Central Amazonia, Brazil.

A new species of Amazophrynella (Anura:Bufonidae) from the southwestern part of the Brazilian Guiana Shield.

Amazophrynella is a genus of the family Bufonidae, currently represented by three species. The type species of the genus, Amazophrynella minuta, however, is a complex of species occurring throughout the Amazonian biome. This group remains problematic taxonomically; the difficulty lays principally in the lack of diagnostic characters in the original description of A. minuta, the lack of molecular data and refined taxonomic comparison of individuals through its wide distribution. We describe a new species of the genus Amazophrynella, distributed in the southwestern part of the Guiana Shield of Brazil based on a series of morphological and molecular characters. The new species differs from others of the genus by presenting a slightly truncated triangular snout, ventral texture covered by many fine granules, white belly covered with black spots and by fifteen molecular autapomorphies in the 16S rDNA fragment. Uncorrected p-distances of a fragment of the 16S mitochondrial rDNA gene revealed high divergence among other Amazophrynella species (9%-14%). Additionally we provide a new diagnosis of topotypic material of Amazophrynella minuta including molecular data. Our results show the existence of a subestimated diversity in the genus Amazophrynella. 

Trypanosoma cruzi disrupts thymic homeostasis by altering intrathymic and systemic stress-related endocrine circuitries.

We have previously shown that experimental infection caused by Trypanosoma cruzi is associated with changes in the hypothalamus-pituitary-adrenal axis. Increased glucocorticoid (GC) levels are believed to be protective against the effects of acute stress during infection but result in depletion of CD4(+)CD8(+) thymocytes by apoptosis, driving to thymic atrophy. However, very few data are available concerning prolactin (PRL), another stress-related hormone, which seems to be decreased during T. cruzi infection. Considering the immunomodulatory role of PRL upon the effects caused by GC, we investigated if intrathymic cross-talk between GC and PRL receptors (GR and PRLR, respectively) might influence T. cruzi-induced thymic atrophy. Using an acute experimental model, we observed changes in GR/PRLR cross-activation related with the survival of CD4(+)CD8(+) thymocytes during infection. These alterations were closely related with systemic changes, characterized by a stress hormone imbalance, with progressive GC augmentation simultaneously to PRL reduction. The intrathymic hormone circuitry exhibited an inverse modulation that seemed to counteract the GC-related systemic deleterious effects. During infection, adrenalectomy protected the thymus from the increase in apoptosis ratio without changing PRL levels, whereas an additional inhibition of circulating PRL accelerated the thymic atrophy and led to an increase in corticosterone systemic levels. These results demonstrate that the PRL impairment during infection is not caused by the increase of corticosterone levels, but the opposite seems to occur. Accordingly, metoclopramide (MET)-induced enhancement of PRL secretion protected thymic atrophy in acutely infected animals as well as the abnormal export of immature and potentially autoreactive CD4(+)CD8(+) thymocytes to the periphery. In conclusion, our findings clearly show that Trypanosoma cruzi subverts mouse thymus homeostasis by altering intrathymic and systemic stress-related endocrine circuitries with major consequences upon the normal process of intrathymic T cell development.