Vertebral pattern and morphology is determined during embryonic segmentation.

BACKGROUND: The segmented nature of the adult vertebral column is based on segmentation of the paraxial mesoderm during early embryogenesis. Disruptions to embryonic segmentation, whether caused by genetic lesions or environmental stress, result in adult vertebral pathologies. However, the mechanisms linking embryonic segmentation and the details of adult vertebral morphology are poorly understood. RESULTS: We induced border defects using two approaches in zebrafish: heat stress and misregulation of embryonic segmentation genes tbx6, mesp-ba, and ripply1. We assayed vertebral length, regularity, and polarity using microscopic and radiological imaging. In population studies, we find a correlation between specific embryonic border defects and specific vertebral defects, and within individual fish, we trace specific adult vertebral defects to specific embryonic border defects. CONCLUSIONS: Our data reveal that transient disruptions of embryonic segment border formation led to significant vertebral anomalies that persist through adulthood. The spacing of embryonic borders controls the length of the vertebra. The positions of embryonic borders control the positions of ribs and arches. Embryonic borders underlie fusions and divisions between adjacent spines and ribs. These data suggest that segment borders have a dominant role in vertebral development.

Shark centra microanatomy and mineral density variation studied with laboratory microComputed Tomography.

Centra of shark vertebrae from three species of Lamniformes (Alopias vulpinus, Carcharodon carcharias and Isurus oxyrinchus) and three species of Carcharhiniformes (Carcharhinus plumbeus, Carcharhinus obscurus and Prionace glauca) were imaged with laboratory microcomputed Tomography (microCT) using volume element (voxel) sizes between 16 and 24 µm. Linear attenuation coefficients were the same in the corpus calcarea (hour-glass-shaped cone) and intermedialia of the lamniforms but were smaller in the intermedialia than in the corpus calcarea of the carcharhiniforms. All centra contained growth bands which were visible as small changes in linear attenuation coefficient. In all six cases, the cross-sections of the cones were close to circular, and the cone angles matched those reported in the literature. Cartilage canals were a prominent structure in the intermedialia of all species, 3D renderings of centra of C. obscurus and I. oxyrinchus diameters showed these canals ran radially outward from the cone walls, and canal diameters were consistent with the limited numerical values in the literature. Somewhat higher calcification levels around the periphery of cartilage canals and of outer surfaces of the intermedialia and corpus calcerea suggest microstructural variation exists at scale below that which can be resolved in the present data sets.

Direct activation of chordoblasts by retinoic acid is required for segmented centra mineralization during zebrafish spine development.

Zebrafish mutants with increased retinoic acid (RA) signaling due to the loss of the RA-inactivating enzyme Cyp26b1 develop a hyper-mineralized spine with gradually fusing vertebral body precursors (centra). However, the underlying cellular mechanisms remain incompletely understood. Here, we show that cells of the notochord epithelium named chordoblasts are sensitive to RA signaling. Chordoblasts are uniformly distributed along the anteroposterior axis and initially generate the continuous collagenous notochord sheath. However, subsequently and iteratively, subsets of these cells undergo further RA-dependent differentiation steps, acquire a stellate-like shape, downregulate expression of the collagen gene col2a1a, switch on cyp26b1 expression and trigger metameric sheath mineralization. This mineralization fails to appear upon chordoblast-specific cell ablation or RA signal transduction blockade. Together, our data reveal that, despite their different developmental origins, the activities and regulation of chordoblasts are very similar to those of osteoblasts, including their RA-induced transition from osteoid-producing cells to osteoid-mineralizing ones. Furthermore, our data point to a requirement for locally controlled RA activity within the chordoblast layer in order to generate the segmented vertebral column.

Vertebral morphology in the tail-whipping common thresher shark, Alopias vulpinus.

Thresher sharks (Alopias spp.) are characterized by an elongated, scythe-like caudal fin that is used in tail-whipping, a behaviour where the tail is thrown overhead to stun prey. Tail-whipping is performed via extreme dorsoventral bending of the vertebral column, and is dramatically different from lateral oscillatory motion used for swimming. Previous work has examined thresher shark vertebral morphology and mechanical properties, but in the context of swimming loads. Our goal was to assess centra morphometrics and microarchitecture for variations that may support extreme dorsoventral bending. We examined anterior and posterior body vertebrae from an embryo, five juvenile, and four adult thresher sharks using micro-computed tomography. We used principal component and landmark analyses to examine variables influencing vertebral morphology and mineral arrangement, respectively. We found that morphology and microstructure significantly varied across body regions and ontogeny. We hypothesize that anterior body vertebrae increase stability, while posterior body vertebrae support the caudal fin. Vertebral size and quantity of mineral structures (lamellae and nodes) increased across ontogeny, suggesting vertebrae adapt over development to support a larger body and tail. Based on our results, we hypothesize that thresher shark vertebrae vary in morphometrics and mineralization (amount and arrangement) supporting the mechanical needs for tail-whipping.

Design and Characterization of Ocular Inserts Loaded with Dexamethasone for the Treatment of Inflammatory Ophthalmic Disease.

The short precorneal residence time of ophthalmic drops is associated with their low absorption; therefore, the development of ocular inserts capable of prolonging and controlling the ophthalmic release of drugs is an interesting option in the design and development of these drugs. A surface response design was developed, specifically the Central Composite Design (CCD), to produce ophthalmic films loaded with Dexamethasone (DEX) by the solvent evaporation method having experimental levels of different concentrations of previously selected polymers (PVP K-30 and Eudragit RS100.). Once optimization of the formulation was obtained, the in vivo test was continued. The optimal formulation obtained a thickness of 0.265 ± 0.095 mm, pH of 7.11 ± 0.04, tensile strength of 15.50 ± 3.94 gF, humidity (%) of 22.54 ± 1.7, mucoadhesion strength of 16.89 ± 3.46 gF, chemical content (%) of 98.19 ± 1.124, release of (%) 13,510.71, and swelling of 0.0403 ± 0.023 g; furthermore, in the in vivo testing the number and residence time of PMN cells were lower compared to the Ophthalmic Drops. The present study confirms the potential use of polymeric systems using PVPK30 and ERS100 as a new strategy of controlled release of ophthalmic drugs by controlling and prolonging the release of DEX at the affected site by decreasing the systemic effects of the drug.

Direct BMP signaling to chordoblasts is required for the initiation of segmented notochord sheath mineralization in zebrafish vertebral column development.

The vertebral column, with the centra as its iteratively arranged building blocks, represents the anatomical key feature of the vertebrate phylum. In contrast to amniotes, where vertebrae are formed from chondrocytes and osteoblasts deriving from the segmentally organized neural crest or paraxial sclerotome, teleost vertebral column development is initiated by chordoblasts of the primarily unsegmented axial notochord, while sclerotomal cells only contribute to later steps of vertebrae formation. Yet, for both mammalian and teleostean model systems, unrestricted signaling by Bone Morphogenetic Proteins (BMPs) or retinoic acid (RA) has been reported to cause fusions of vertebral elements, while the interplay of the two signaling processes and their exact cellular targets remain largely unknown. Here, we address this interplay in zebrafish, identifying BMPs as potent and indispensable factors that, as formerly shown for RA, directly signal to notochord epithelial cells/chordoblasts to promote entpd5a expression and thereby metameric notochord sheath mineralization. In contrast to RA, however, which promotes sheath mineralization at the expense of further collagen secretion and sheath formation, BMP defines an earlier transitory stage of chordoblasts, characterized by sustained matrix production/col2a1 expression and concomitant matrix mineralization/entpd5a expression. BMP-RA epistasis analyses further indicate that RA can only affect chordoblasts and their further progression to merely mineralizing cells after they have received BMP signals to enter the transitory col2a1/entpd5a double-positive stage. This way, both signals ensure consecutively for proper mineralization of the notochord sheath within segmented sections along its anteroposterior axis. Our work sheds further light onto the molecular mechanisms that orchestrate early steps of vertebral column segmentation in teleosts. Similarities and differences to BMP's working mechanisms during mammalian vertebral column formation and the pathomechanisms underlying human bone diseases such as Fibrodysplasia Ossificans Progressiva (FOP) caused by constitutively active BMP signaling are discussed.

Microstructure of Vertebrae, Ribs, and Gastralia of Triassic Sauropterygians-New Insights into the Microanatomical Processes Involved in Aquatic Adaptations of Marine Reptiles.

Isolated ribs and vertebrae of Middle Triassic sauropterygians are studied. The vertebrae have a well-defined large cavity in their centra, which is a unique feature and is without any modern analogue. The articular facets of vertebrae are made of endochondral bone including calcified as well as uncalcified cartilage. Vertebrae are pachyosteosclerotic in the pachypleurosaurs Neusticosaurus and Serpianosaurus from the Alpine Triassic, and osteosclerotic in the placodont, in the medium-sized Nothosaurus marchicus, and in the pachypleurosaur Anarosaurus. In large Nothosaurus specimens, the vertebrae are cavernous. The ribs of all sampled specimens are osteosclerotic, which resembles the microanatomy of long bones in all studied taxa. The proximal to medial part of ribs mainly consists of a compact periosteal cortex surrounding an inner endosteal territory. Toward the distal end of the ribs, the periosteal thickness decreases whereas the endosteal territory increases. Despite a shift from periosteal versus endosteal tissues, global rib compactness remains relatively constant. Osteosclerosis in ribs and vertebrae is reached by the same processes as in the long bones: by a relative increase in cortex thickness that is coupled by a reduction of the medullary cavity, by the persistence of calcified cartilage, and by an inhibition of remodeling although some resorption may occur but without complete redeposition of bone. Processes differ from those observed in Permian marine reptiles and some mosasaurines, where either extensive remodeling or inhibition of bone resorption leads to osteosclerosis. Besides differences regarding the microanatomy, all studied bones of a taxon are consistent in their bone tissue type. Anat Rec, 302:1770-1791, 2019. © 2019 American Association for Anatomy.

An adult osteopetrosis model in medaka reveals the importance of osteoclast function for bone remodeling in teleost fish.

Osteoclasts play important roles during bone growth and in maintaining bone health and bone homeostasis. Dysfunction or lack of osteoclasts leads to increased bone mass and osteopetrosis phenotypes in mouse and human. Here we report a severe osteopetrosis-like phenotype in transgenic medaka fish, in which membrane bound EGFP (mEGFP) was expressed in osteoclasts under control of the cathepsin K promoter (ctsk:mEGFP). In contrast to reporter lines with GFP expression in the cytoplasm of osteoclasts, adult fish of the mEGFP line developed bone defects indicative for an osteoclast dysfunction. Activity of tartrate-resistant acid phosphatase (TRAP) was down-regulated and excess bone was observed in most parts of the skeleton. The osteopetrotic phenotype was particularly obvious at the neural and haemal arches that failed to increase their volume in growing fish. Excess bone caused severe constriction of the spinal cord and the ventral aorta. The continuation of tooth development and the failure to shed teeth resulted in severe hyperdontia. Interestingly, at the vertebral column vertebral body arches displayed a severe osteopetrosis, while vertebral centra had no or only a mild osteopetrotic phenotype. This confirms previous reports from cichlids that, different from the arches, allometric growth of fish vertebral centra initially does not depend on the action of osteoclasts. Independent developmental mechanism that shapes arches and vertebral centra can also lend support to the hypothesis that vertebral centra and arches function as independent developmental modules. Together, this medaka osteopetrosis model confirms the importance of proper osteoclast function during normal skeletal development in teleost fish that requires bone modeling and remodeling.

Complications related to the type of epicutaneous catheter in a cohort of neonates / Complicaciones relacionadas al tipo de catéter percutáneo en una cohorte de neonatos / Complicações relacionadas ao tipo de cateter epicutâneo em uma coorte de neonatos

Aims: To analyze the relationship between the type of epicutaneous catheter installed and the time until the occurrence of complications that motivate early removal of the device. Method: Prospective cohort study conducted in a neonatal intensive care unit of a private hospital in the city of São Paulo, in the period July 1st 2010 to June 30th 2011. The cohort consisted of neonates undergoing the installation of polyurethane double-lumen or silicone single-lumen epicutaneous catheter. Results and discussion: We analyzed 270 catheters. There was no association between the type of epicutaneous catheter and time until the occurrence of complications (p=0,45). The polyurethane double-lumen catheter presented higher average time of catheter permanence (p≤0,01). Conclusion: Both types of epicutaneous catheters have enabled intravenous infusion over 10 days and showed no major complications.

Analizar la relación entre el tipo de catéter percutáneo instalado y el tiempo que transcurre hasta la ocurrencia de complicaciones que motivan la retirada precoz del dispositivo. Método: Cohorte prospectiva, realizada en una unidad de cuidados intensivos neonatales de un hospital privado en la ciudad de São Paulo, en el período de 1 de julio de 2010 a 30 de junio de 2011. La cohorte estuvo compuesta por neonatos sometidos a la instalación del catéter percutáneo doble lumen de poliuretano o mono lumen de silicona.Resultados y discusión: Se analizaron 270 catéteres. No existió asociación entre el tipo de catéter percutáneo y el tiempo transcurrido hasta la ocurrencia de complicaciones (p=0,45). El catéter doble lumen de poliuretano presentó mayor tiempo medio de permanencia del catéter (p≤0,01). Conclusiones: Los dos tipos de catéteres percutáneos permitieron el uso de la infusión intravenosa por más de 10 días y no presentaron complicaciones más graves.

Objetivos: analisar a relação entre o tipo de cateter epicutâneo instalado e o tempo até a ocorrência de complicações que motivam a remoção precoce do dispositivo. Método: Coorte prospectiva, realizada em uma unidade de cuidados intensivos neonatais de um hospital privado na cidade de São Paulo, no período de 01 de julho de 2010 a 30 de junho de 2011. A coorte foi composta por neonatos submetidos à instalação do cateter epicutâneo duplolúmen de poliuretano ou monolúmen de silicone. Resultados e discussão: Foram analisados 270 cateteres. Não houve associação entre o tipo de cateter epicutâneo e o tempo até a ocorrência de complicações (p=0,45). O cateter duplolúmen de poliuretano apresentou maior tempo médio de permanência do cateter (p≤0,01). Conclusão: Os dois tipos de cateteres epicutâneos permitiram a infusão intravenosa por mais de 10 dias e não apresentaram complicações mais graves.

Oclusión de arteria central de retina y Rabdomiosarcoma de etmoides: informe de un caso / Occlusion of central retinal artery and ethmoid rhabdomyosarcoma. report of a case

La mayoría de los tumores de senos paranasales se presenta en estado avanzado y, por lo general, las tasas de curación son precarias. El carcinoma de células escamosas es el tipo más frecuente de tumor maligno en nariz y senos paranasales (70–80 por ciento). Los papilomas son entidades diferenciadas que pueden experimentar degeneración maligna. Los cánceres crecen dentro de los límites óseos de los senos y, a menudo, son asintomáticos hasta que erosionan e invaden las estructuras adyacentes. En este trabajo se describe el caso de una paciente atendida en nuestro servicio con diagnóstico de rabdomiosarcoma de etmoides complicado con oclusión de arteria central de la retina, complicación poco frecuente en nuestro medio(AU)

Two patients are reported with hypernephroma at Basuheeb Hospital , Yemen , 32 and 75 years, which are not, collected risk factors associated with the underlying pathology . The symptoms occurred in one of them were right lumbar pain and hematuria , and in the other , bilateral lumbar pain , with the same affected right kidneys in both patients. Renal ultrasound and urography confirmed the pathology in both cases by tomography . Total nephrectomy was applied , obtaining histologic diagnosis of clear cell renal carcinoma and, according to TNM classification , both were found in stage II

Avaliação da acurácia diagnóstica da técnica de biopsia estereotáxica na investigação de processos expansivos encefálicos / Evaluation of the diagnostic accuracy of stereotactic biopsy technique in the investigation of expansive brain processes

Introdução: As lesões expansivas do sistema nervoso central constituem um grupo diversificado de condições neoplásicas e não neoplásicas que podem ocorrer em virtualmente qualquer região anatômica e em pacientes de qualquer idade. A biópsia estereotáxica cerebral (BEC) é um procedimento seguro que pode ser usado na determinação do diagnóstico histopatológico desses processos. O objetivo deste estudo foi avaliar a acurácia da técnica de BEC na determinação do diagnóstico de processos expansivos intraparenquimatosos cerebrais. Métodos: Foram avaliadas 114 amostras distintas de BEC, através da técnica de hematoxilina-eosina, com o intuito de estabelecer o diagnóstico histológico de cada caso. As neoplasias secundárias foram avaliadas pela técnica de imunoistoquímica para estabelecer o sítio primário destas lesões. Resultados: Foi encontrada um média de idade igual a 52.92 anos (±8,125), com uma idade mediana de 51,0 anos. O grupo de pacientes incluiu 64 homens (56%). O número de fragmentos analisados em cada caso era igual a 12. Os fragmentos mediam em média 8,0 milímetros de largura e 1,0 mm de comprimento. O diagnóstico histológico de neoplasia foi estabelecido em 95 casos (83,3%), sendo o astrocitoma difuso (24,5%) e o glioblastoma (22,8%) os tipos histológicos mais frequentes. Foram encontrados 10 casos de envolvimento cerebral por neoplasias secundárias, sendo o linfoma não-hodgkiniano difuso de células B e o adenocarcinoma (80% em conjunto) os tipos predominantes. As lesões não neoplásicas corresponderam a 19 casos (16,7%) da amostra. Conclusão: A acurácia da BEC corresponde cerca de 92%, favorecendo seu emprego principalmente na investigação clínica de processos neoplásicos

Introduction: Expansive brain lesions of the central nervous system are a diverse group of neoplastic and non-neoplastic conditions that may occur in virtually any anatomical region and in patients of all ages. Stereotactic brain biopsy (SBB) is a safe procedure that can be used to determine the histopathologic diagnosis of these processes. The aim of this study was to evaluate the accuracy of SBB in determining the diagnosis of expansive intraparenchymal brain processes. Methods: We evaluated 114 different samples of SBB through the hematoxylin-eosin technique in order to establish the histologic diagnosis of each case. Secondary neoplasms were evaluated by immunohistochemistry to determine the primary site of these lesions. Results: Patient mean age was 52.92 years (± 8.125), with a median of 51.0 years. The group of patients included 64 men (56%). Twelve fragments were analyzed in each case. On average, fragments were 8.0 mm wide and 1.0 mm long. The histological diagnosis of cancer was established in 95 cases (83.3%). Diffuse astrocytoma (24.5%) and glioblastoma (22.8%) were the most frequent histological types. There were 10 cases of cerebral involvement by secondary neoplasms, and diffuse non-Hodgkin B-cell lymphoma and adenocarcinoma (80% combined) were the predominant types. There were 19 cases of non-neoplastic lesions (16.7%) in this sample. Conclusion: The accuracy of SBB was 92%, which favors its use in clinical research of neoplastic processes