Pericytes in the Placenta: Role in Placental Development and Homeostasis.

The placenta is the most variable organ, in terms of structure, among the species. Besides it, all placental types have the same function: production of viable offspring, independent of pregnancy length, litter number, or invasion level. The angiogenesis is a central mechanism for placental functionality, due to proper maternal-fetal communication and exchanges. Much is known about the vasculature structure, but little is known about vasculature development and cellular interactions. Pericytes are perivascular cells that were described to control vasculature stability and permeability. Nowadays there are several new functions discovered, such as lymphocyte modulation and activation, macrophage-like phagocytic properties, tissue regenerative and repair processes, and also the ability to modulate stem cells, majorly the hematopoietic. In parallel, placental tissues are known to be a particularly immune microenvironment and a rich stem cell niche. The pericyte function plethora could be similar in the placental microenvironment and could have a central role in placental development and homeostasis.

Optimization of Canine Placenta Decellularization: An Alternative Source of Biological Scaffolds for Regenerative Medicine.

Due to the scarcity of tissues and organs for transplantation, the demand for bioengineered tissues is increasing with the advancement of technologies and new treatments in human and animal regenerative medicine. Thus, decellularized placental extracellular matrix (ECM) has emerged as a new tool for the production of biological scaffolds for subsequent recellularization and implantation for recovery of injured areas or even for replacement of organ and tissue fractions. To be classified as an ideal biological scaffold, the ECM must be acellular and preserve its proteins and physical features to be useful for cellular adhesion. In this context, we developed a process of decellularization of canine placentas with 35 and 40 days of gestation using dodecyl sulfate sodium under immersion and agitation in sterile conditions. Before use of this scaffold in recellularization processes, the decellularization efficiency needs to be confirmed by the absence of cellular content and an irrelevant amount of reminiscent DNA. Both vasculature architecture and ECM proteins, such as collagen types I, III, and IV, laminin, and fibronectin, were preserved with our method. In this way, we established a new biological scaffold model that could be used for recellularization in regenerative medicine of tissues.

Mouse placental scaffolds: a three-dimensional environment model for recellularization.

The rich extracellular matrix (ECM) and availability make placenta eligible as alternative biomaterial source. Herein we produced placental mouse scaffolds by decellularization, and structure, composition, and cytocompatibility were evaluated to be considered as a biomaterial. We obtained a cell-free scaffold containing 9.42 ± 5.2 ng dsDNA per mg of ECM, presenting well-preserved structure and composition. Proteoglycans were widespread throughout ECM without cell nuclei and cell remnants. Collagen I, weak in native placenta, clearly appears in the scaffold after recellularization, opposite distribution was observed for collagen III. Fibronectin was well-observed in placental scaffolds whereas laminin and collagen IV were strong expressed. Placental scaffolds recellularization potential was confirmed after mouse embryonic fibroblasts 3D dynamic culture, resulting in massive scaffold repopulation with cell-cell interactions, cell-matrix adhesion, and maintenance of natural morphology. Our small size scaffolds provide a useful tool for tissue engineering to produce grafts and organ fragments, as well as for cellular biology purposes for tridimensional culture substrate.

Decellularized bovine cotyledons may serve as biological scaffolds with preserved vascular arrangement.

Technically produced scaffolds are common to establish transplantable tissues for regenerative medicine, but also biological ones that are closer to the natural condition become of interest. Placentas are promising, because they represented available, complete organs with rich extracellular matrix (ECM) and well-developed vasculature that easily could build anastomoses to a host's organ. Only placentas from larger animal models such as the bovine meet the dimensions large enough for most organs but are not adequately described yet. We here studied the nature of the ECM in 27 natural and decellularized bovine cotyledons, that is, the fetal part of the placentomes, by means of histology, immunohistochemistry, and electron microscopy. Successful decellularization was done by perfusion with 0.01%, 0.1%, and 0.5% sodium dodecyl sulfate each and subsequent immersion in 1% Triton X-100, resulting in a removal of cells and DNA, whereas the structure of the allantochorionic surface and villi was preserved. Although some fibres disappeared, also the arrangement of the main ECM proteins was largely similar before and after decellularization: Along the larger vessels, a densely packed network of thick fibres occurred, organized in layers without cells or spaces in between. Collagen IV, fibronectin, and laminin contributed to those areas. In contrast, collagen I and III characterized the meshwork of medium-sized and thin fibres in the mesenchyme, respectively. In conclusion, decellularized bovine cotyledons indeed had characteristics of a biological scaffold and provide an interesting alternative to develop large-scale scaffolds with complex vascular architecture for tissue engineering purposes.

Common calcaneal tendon repair with glycerin-preserved carotid artery xenografts and autologous bone marrow mononuclear cells in rabbits / Reparo de tendão calcanear comum de coelhos com xenoimplante de artéria carótida preservada em glicerina associado a células mononucleares da medula óssea autólogas

Fifteen adult rabbits were used to evaluate the repair of experimental common calcaneal tendon defects treated with glycerin-preserved canine carotid artery xenografts alone or associated with autologous mononuclear bone marrow cells (AMCs). Rabbits were submitted to daily clinical examination; implanted sites were analyzed under light microscopy within 15, 30 and 60 days of surgery. Pelvic limbs receiving xenografts associated with AMCs had better physical performance as well as higher collagen fiber, fibroblast, lymphocyte and new vessel counts at all postoperative time points considered. Glycerin-preserved canine carotid artery xenografts associated with AMCs constituted an effective method for common calcaneal tendon repair in rabbits.(AU)

Utilizou-se 15 coelhos adultos para avaliar o reparo de lesão do tendão calcanear comum com implante de artéria carótida de cães, preservada em glicerina, associado ou não a células mononucleares autólogas da medula óssea (CMAs). Os animais foram observados diariamente por meio de avaliações clínicas e o local do implante foi analisado sob microscopia de luz decorridos 15, 30 e 60 dias de pós-operatório. Notou-se em todos os períodos de observação, com o implante associado às CMAs, melhor desempenho físico dos membros pélvico e maior intensidade de fibras colágenas, fibroblastos e linfócitos e neovascularização. A utilização de xenoimplante de artéria carótida de cães preservada em glicerina associado à administração de células mononucleares da medula óssea foi eficiente no reparo do tendão calcanear comum de coelhos.(AU)

Comparison of palmar digital neurectomy by the guillotine technique and palmar digital neurotomy associated with end-to-side neurorrhaphy in mares / Comparação entre neurectomia por técnica de guilhotina e neurotomia associada à neurorrafia em alça de balde em nervo digital palmar de éguas

Five mares were submitted to palmar digital neurectomy by the guillotine technique and palmar digital neurotomy followed by end-to-side neurorrhaphy (right and left thoracic limbs, respectively). Mares were checked for local pain sensation using hoof tester and submitted to lameness workup at 15-day intervals. No evidence of painful neuroma formation was detected. Palmar digital nerve (PDN) stump segments were collected within 60 days of surgery. Mean left and right limb PDN stump thickness corresponded to 5.96 mm and 7.16 mm, respectively. Schwann cells prevailed over connective healing tissue in all PDN stumps studied. Well-formed nerve-like structures with better organized nervous tissue and predominance of parallel nerve fiber orientation were documented in left limb PDN stumps. End-to-side neurorrhaphy tended to promote tissue organization, potentially reducing the chances of neuroma formation...

O nervo digital palmar (NDP) lateral do membro torácico direito (MTD) de cinco equinos fêmeas foi submetido à neurectomia pela técnica da guilhotina, e o do membro torácico esquerdo (MTE) à neurotomia e neurorrafia término-lateral. Os animais foram avaliados a cada 15 dias quanto ao teste de sensibilidade cutânea com pressão local com pinça de casco e de claudicação, não sendo notados sinais clínicos de neuroma doloroso. Aos 60 dias pós-cirurgia coletou-se segmentos dos cotos proximais dos NDPs. Os dos MTDs apresentavam em média, a espessura de 7,16 mm e aos dos MTEs de 5,96 mm. Nos cotos proximais dos nervos dos membros direito e esquerdo notou-se predominância de células de Schwann à grande quantidade de tecido conjuntivo cicatricial. Os do MTEs apresentavam estruturas de nervo típico, bem constituídas, com maior organização do tecido nervoso e predomínio de fibras nervosas orientadas paralelamente. A neurorrafia termino-lateral apresentou tendência a ocasionar maior organização entre as estruturas analisadas, o que lhe conferiu menor potencial em desenvolver neuromas dolorosos...

Abraçadeira de náilon na correção de entrópio juvenil em cães shar-pei / Abrazadeira de nyllon en corrección de entropión juvenil en perros shar-pei / Temporary correction of juvenile entropion in shar pei dogs with nylon band

O entrópio é a inversão de parte ou de toda margem palpebral, fazendo com que a pele com pelos atrite as superfícies conjuntival e corneal causando irritação. Em cães o entrópio pode ser hereditário ou adquirido, sendo que, algumas raças apresentam certa predisposição. Para propor um método mais eficiente, com um material alternativo para a correção temporária do entrópio juvenil em filhotes de cães da raça Shar Pei, foram utilizados 10 animais, com peso variável, com idades de até 12 meses, portadores de entrópio juvenil. Com os animais devidamente preparados e anestesiados foram aplicadas as abraçadeiras de náilon em número e angulação referente ao grau de entrópio presente. Para a passagem da abraçadeira de náilon 2x80mm pelo subcutâneo palpebral foi usada agulha hipodérmica 40x16, na qual foi posicionada a abraçadeira em sua luz para que pudesse atravessar as duas porções de pele, formando então uma ?prega?. A aplicação das abraçadeiras demonstrou-se de fácil e rápida execução. As abraçadeiras permaneceram de foram efetiva nas pálpebras, garantindo a eversão das margens palpebrais, variando entre 5 e 12 semanas, com uma média de permanência de 8 semanas. Alguns animais tiveram que ser reoperados sucessivamente e foram acompanhados até a blefaroplastia definitiva. As complicações observadas são referentes ao prurido e ao desconforto inicial. A abraçadeira de náilon 2x8mm se constitui em material barato, de fácil esterilização, com aplicação rápida e efetiva nos casos de entrópio juvenil em cães da raça Shar Pei, mantendo a segurança e integridade dos bulbos oculares por 8 semanas em média.

The entropion is the reversing of part or all of eyelid margin, causing the skin with hair rubbing the surfaces conjunctival and corneal making irritation. Entropion can be inherited or acquired and some races of dogs have predisposition. To suggest a more efficient method, with an alternative material for the temporary eyelids fixation in juvenile Shar Pei dogs, 10 animals were anesthetized and prepared properly applied the ties of nylon band in number and angle related to the degree of entropion present. A 40x16 hypodermic needle was used for the passage of the 2x8mm nylon band by subcutaneous eyelid, which the band placed in its light so that it could cross the two portions of the skin, then forming a ?fold?. The animals remained with the owners, returning weekly for evaluation. The application of bands has shown itself to easy and quick implementation. The animals remained with ?Elizabethan? collar because it was observed itching in the first 72 hours after application of bands. There was no presence of bleeding or formation of infectious process in any of the procedures performed. The permanence of bands in the eyelids effectively, ensuring patency of eyelid margins, ranged between 5 and 12 weeks, with an average length of stay of 8 weeks. Some animals had to be reoperated and were followed until the final blepharoplasty. Complications are observed for the itching and the initial discomfort. The 2x8mm nylon band whether it is in material cheap, easy sterilization, with rapid and effective application in cases of juvenile entropion in Shar Pei dogs, maintaining the security and integrity of ocular balls for 8 weeks on average and can thus be recommended its clinical use.

El entropión es la inversión de parte o de toda margen del párpado, haciendo con que la piel, con pelos, friccione las superficies conjuntival y de la córnea causando irritación. En perros, el entropión puede ser hereditario o adquirido, siendo que, algunas razas presentan cierta predisposición. Para un método más eficiente, con material alternativo para la corrección temporaria del entropión juvenil en cachorros de perros de la raza Shar Pei, se ha utilizado 10 animales, con peso variable, con edades de hasta 12 meses, portadores de entropión juvenil. Con los animales debidamente preparados y anestesiados se aplicó las abrazaderas de nylon en número y ángulo referente al grado del entropión propio. Para el pasaje de la abrazadera de nylon 2x80 mm por el subcutáneo del párpado se utilizó una aguja hipodérmica 40x16, en la cual se posicionó la abrazadera en su luz para que pudiera atravesar las dos porciones de piel, formando entonces una ?pliega?. La aplicación de las abrazaderas se demostró de fácil y rápida ejecución. Las abrazaderas permanecieron de forma efectiva en los párpados, garantizando la eversión de las márgenes palpebrales, variando entre 5 y 12 semanas, con una media de permanencia de 8 semanas. Algunos animales tuvieron que ser nuevamente operados y acompañados hasta la blefaroplastia definitiva. Las complicaciones observadas son referentes al prurito y la incomodidad inicial. La abrazadera de nylon 2x8 mm se constituye en material barato, de fácil esterilización, de rápida aplicación y efectiva en los casos de entropión juvenil en perros de la raza Shar Pei, manteniendo seguridad e integridad de los bulbos oculares por 8 semanas en media.

Caracterização vascular dos setores e segmentos arteriais renais de suínos / Caracterización vascular de los sectores y segmentos arteriales renales de porcinos / Vascular characterization of the sectors and renal arterial segments of swine

As artérias renais, originárias da aorta, dividem-se primeiramente em artérias renais setoriais, que a seguir se ramificam, originando as artérias renais segmentares. A localização topográfica desses vasos estabelece, respectivamente, a presença dos setores e segmentos renais. Para determinar o comportamento vascular arterial e consequente distribuição em setores e segmentos renais de suínos, foram utilizados dezesseis pares de rins de suínos, cuja análise e observação permite descrever: a artéria renal, única em sua maioria, divide-se em ramos setoriais craniais e caudais em 14 rins direitos e 13 esquerdos, em ramos setoriais dorsais e ventrais em três rins esquerdos e um direito; ainda, em apenas um exemplar esquerdo a artéria renal mostrou-se dupla em sua origem. Para os rins direito e esquerdo analisados, tanto o setor cranial, quanto o caudal apresentaram as seguintes artérias renais segmentares: dorsocranial, dorsomédiocranial, dorsomédio, dorsomédiocaudal, dorsocaudal, ventrocranial, ventromédiocranial, ventromédio, ventromédiocaudal e ventrocaudal. Quando presentes os setores renais dorsal e ventral, os vasos renais segmentares distribuíram-se como cranial, médiocranial, médio, médiocaudal e caudal, de acordo com sua disposição topográfica no órgão.

The renal arteries, original of the aorta, become separated firstly in sectorial renal arteries, that to proceed if they ramify, originating the segmentary renal arteries. The topographical location of those vases establishes, respectively, the presence of the sections and renal segments. To determine the arterial vascular behavior and consequent distribution in sections and renal segments of swine, it was used sixteen pairs of swine kidneys, whose analysis and observation allows to describe: the renal artery, only in it majority, becomes separated in cranial sectorial branches and flows in 14 right kidneys and 13 left, in number and ventral sectorial branches in three left kidneys and a right; still, in just a left copy the renal artery couple was shown in its origin. For the right and left kidneys analyzed, as much the cranial section as the flow they presented the following segmentary renal arteries: dorsocranial, dorsomediumcranial, dorsomedium, dorsomediumcaudal, dorsocaudal, ventrocranial, ventromediumcranial, ventromedium, ventromediumcaudal and ventrocaudal. When dorsal and ventral renal sections are present, the segmentary renal vases were distributed as cranial, mediumcranial, medium, mediumcaudal and caudal, in agreement with its topographical disposition in the organ.

Las arterias renales, originarias de la aorta, se dividen primeramente en arterias renales sectoriales, que a seguir se ramifican, originando las arterias renales segmentares. La localización topográfica de esos vasos establece, respectivamente, la presencia de los sectores y segmentos renales. Para determinar el comportamiento vascular arterial y consecuente distribución en sectores y segmentos renales de porcinos fueron utilizados dieciséis pares de riñones (de porcinos), cuya análisis y observación permite describir: la arteria renal, única en su mayoría, se divide en ramas craneal y caudal en 14 riñones derechos y 13 izquierdos, en ramas dorsal y ventral en tres riñones izquierdos y un derecho; solamente en un ejemplar izquierdo la arteria renal se mostró dupla en su origen. Para los riñones derecho e izquierdo analizados, tanto el sector craneal como el caudal presentaron las siguientes arterias renales segmentares: dorso craneal, dorso medio craneal, dorso medio, dorso medio caudal, dorso caudal, ventro craneal, ventro medio craneal, ventro medio, ventro medio caudal y ventro caudal. Cuando presentes los sectores renales dorsal y ventral, los vasos renales segmentares se distribuirán como craneal, medio craneal, medio, medio caudal y caudal, de acuerdo con su disposición topográfica en el órgano.

Correlação entre a pressão arterial média e o fluxo sangüíneo na artéria oftalmica externa em gatos (felis catus linnaeus, 1758) / Correlation between arterial pressure and blood flow in the external ophthalmic artery in cats (felis catus linnaeus, 1758)

Foram utilizados 20 gatos sem raça definida, com massa corpórea entre 2 e 4 quilogramas, hígidos, anestesiados com tiletamina e zolazepam (6,0 mg/kg). A artéria femoral foi canulada de forma asséptica e um manômetro acoplado a uma coluna de ar foi conectada ao cateter, a PAM foi aferida antes e a cada 15 minutos até o término do exame ultra-sonográfico. A fluxometria da artéria oftálmica externa foi obtida através do equipamento de ultra-sonografia dotado de eco-doppler, com transdutor setorial de 6,0 MHz, aplicado diretamente sobre a córnea. Cada olho teve o fluxo de sua artériaaferido pelo programa do próprio aparelho, sendo tomadas três amostras. O índice de resistência vascular foi calculado com base nos valores do fluxo sistólico e diastólico médio de cada vaso. Obteve-se um valor médio para a PAM de 144,9 ± 26,68 mmHg e uma velocidade de fluxo de 41,3 ± 14,28 cm/s para a artéria oftálmica externa no olho direito em sístole, 23,95 ± 11,46 cm/s em diástole e 42,75 ± 12,64 cm/s no olho esquerdo em sístole, 25,45 ± 9,61 cm/s em diástole, não existindo diferença significativa entre os olhos. O índice de resistência vascular calculado foi de 0,4175 para a artéria oftálmica externa no olho direito e 0,4015 para a do olho esquerdo, sem diferença significativa entre os olhos. Os resultados apontam para um mecanismo intrínseco de controle do fluxo, controlado por fatores locais na artéria oftálmica externa. Os valores do índice de resistência denotam uma artéria de baixo fluxo. Como conclusão, têm-se os valores de referência acima citados para a PAM e para o fluxo sangüíneo na artéria oftálmica externa em gatos sem raça definida anestesiados com tiletamina e zolazepam, e a informação de que não existe correlação entre esses valores.

There were used 20 mixed breed cats, both male and female, with body mass between 2 and 4 kilograms, that received anesthesia with tiletamine and zolazepam (6,0 mg/kg). The femoral artery was assepticale cannulated and a manometer connected to an air column was connected to the catheter. The MAP was surveyed before and every 15 minutes until the end of the ultrasound examination. The flow of the external ophthalmic artery was measured through the ultrasond equipment, with an echo-doppler and a sectorial transducer of 6.0 MHz, directly applied to the cornea. Each eye had the artery flow surveyed by the equipment's own device, 3 samples being taken. The vascular resistance index was calculated based on the mean values of systolic and diastolic flow of each vasses. An average value for the MAP of 144.9 ± 26.68 mmHg and a flow of 14.28 ± 41.3 cm/sec for the external ophthalmic artery in the right eye in systole, 23.95 ± 11.46 cm/sec in diastole and 42.75 ± 12.64 cm/sec in the left eye in systole, 25.45 ± 9.61 cm/sec in diastole, were verified, there being no significant difference between the eyes. The calculated index of vascular resistance was of 0.4175 ± 0.0774 for the external ophthalmic artery in the right eye and 0,4015 ± 0.0719 for the left eye, without any significant difference between the eyes. The results point to an intrinsic mechanism of flow control, controlled by local factors in the external ophthalmic artery. The values of the resistance index denote a low flow artery. Concluding, this study revealed the reference values, above cited, for the MAP and the blood flow in the external ophthalmic artery in mixed breed cats, anesthetized with tiletamine and zolazepam, and the information that there is no correlation between these values.

Segmentos arteriais dos rins de queixadas (Tayassu pecari Link, 1795) / Arterial segments of kidneys in white-lipped peccaries (Tayassu pecari Link, 1795)

Foram estudados 18 pares de rins de queixadas (Tayassu pecari), cujas artérias foram injetadas com solução corada de Vinilite dissolvido em acetona P.A., em seguida submetidos a corrosão ácida. Os moldes vasculares assim obtidos permitiram observar que: a) as artérias renais, sempre únicas, dividem-se primeiramente em ramos setoriais renais, sendo esses cranial, dorsal, dorsocranial, dorsocaudal, ventral, ventrocranial, ventrocaudal e caudal; b) as artérias segmentares renais, oriundas da segunda divisão das artérias renais, de acordo com a sua disposição topográfica, constam de: cranial, mediocranial, média, mediocaudal, caudal, dorsal e ventral; c) independente da modalidade em que se apresentam, os segmentos renais encontram-se separados entre si por áreas paucivasculares.

Was studied 18 pairs of White-lipped peccaries kidneys (Tayassu pecari), that has your renal arteries injected whit Vinilit dissolved in P.A. acetone e colored, following submitted to acid corrosion. The vascular molds like this obtained propose that: a) the renal arteries, always single, to divide firstly in setorial renal branches, being these cranial, dorsal, dorsocranial, dorsocaudal, ventral, ventrocranial, ventrocaudal and caudal; b) the segmentary renal arteries, originating from second division of the renal arteries, in agreement with your topographical disposition, consists of: cranial, mediocranial, middle, mediocaudal, caudal, dorsal and ventral; c) independent of the modality in which to introduce, the renal segments are separated amongst themselves by paucivasculars areas.