Effects of aging on the architecture of the ileocecal junction in rats.

AIM: To evaluate the structural organization of the elastic and collagen fibers in the region of the ileocecal transition in 30 young and old male Wistar rats. METHODS: Histology, immunohistochemistry (IHC), transmission electron microscopy and scanning electron microscopy were employed in this study. The results demonstrated that there was a demarcation of the ileocecal region between the ileum and the cecum in both groups. RESULTS: The connective tissue fibers had different distribution patterns in the two groups. IHC revealed the presence of nitric oxide synthase, enteric neurons and smooth muscle fibers in the ileocecal junctions (ICJs) of both groups. Compared to the young group, the elderly group exhibited an increase in collagen type I fibers, a decrease in collagen type III fibers, a decreased linear density of oxytalan elastic fibers, and a greater linear density of elaunin and mature elastic fibers. CONCLUSION: The results revealed changes in the patterns of distribution of collagen and elastic fibers that may lead to a possible decrease in ICJ functionality.

Fibroelastic components of the vesicourethral junction of rats in the aging process / Componentes fibroelásticos de la unión vesicouretral de ratas en el proceso de envejecimiento

The vesicourethral junction comprising the vesical trigone, is relevant in setting and positioning of the urinary bladder, along with the vesical neck, fixed by lateral ligaments of the bladder and tendinous arch of the pelvis fascia. Namely,the puboprostatic ligament (men) and the pubovesical (women). The circular set elastic fibers in this junction are important and valuable in the elasticity and plasticity of the area, allowing quick expansion and withdrawal with the flow of urine, and associated to smooth muscle tissue and nerve control form an important collective to maintain urinary continence. The objective of the present study is to describe the elastic system in the vesicouretral junction in relation to aging and its involvement in the states of urinary continence and incontinence, as well as the study of the vesicouretral junction in various age groups while evaluating with electron transmission microscopy. To carry out the study, 12 Wistar rats were used, divided into groups: neonate (4 animals), adult group (4 animals) and aged group (4 animals). Electron transmission microscopy with use of tanic acid technique associated to glutaraldehyde fixation, satisfactorily showed the extreme structural differences between mature elaunin and oxytalan fibers present between intercelular spaces and bundles of collagen fibers. The phases of elastogenesis in neonate animals and degradation of the elastic system of older animals were also evaluated.

La unión vesico-uretral, componente del trígono vesical, posee una relevante importancia en la fijación y posicionamiento de la vejiga urinaria conjuntamente con el cuello vesical, fijado por los ligamentos laterales de la vejiga y arco tendinoso de la fascia de la pelvis. Principalmente, sus componentes anteriores son: el ligamento puboprostático en los hombres y el ligamento pubovesical en las mujeres. Las fibras elásticas dispuestas circularmente en esta unión, son de valiosa importancia en la elasticidad y plasticidad de la región, permitiendo expansión y retiro rápido con el flujo de la orina, y asociado a musculatura lisa y control nervioso forman un conjunto importante para el mantenimiento de la continencia urinaria. Debido a existencia de puntos no esclarecidos en esta región en relación al sistema elástico y su participación en los estados de continencia/incontinencia urinaria, el presente trabajo tiene por objetivo el estudio de la unión vesico-uretral evaluándola en diferentes grupos etarios, a través de la microscopía electrónica de transmisión. Fueron utilizados 12 ratones Wistar, divididos en grupo de neonatos (4 animales), grupo adulto (4 animales) y grupo de ratones viejos (4 animales). La microscopía electrónica de transmisión, con uso de la técnica del ácido tánico asociado al fijador glutaraldeído, mostró satisfactoriamente las diferencias ultraestructurales entre las fibras elásticas maduras, elaunínicas y oxitalánicas, presentes entre los espacios intercelulares de las células musculares y haces de fibras colágenas, y también fases de elastogénesis en animales neonatos y envejecimiento y degradación del sistema elástico en los animales mayores.

Efeitos do envelhecimento sobre os componentes fibroelásticos da junção vésico-uretral: uma breve revisão / Effects of aging on the components of fibroelastic-urethral junction vésico: a brief review

A junção vésico-uretral (JVU) é um dos componentes do trígono da bexiga que juntamente com o colo vesical possui relevante importância para fixação e posicionamento da bexiga urinária. A JVU é formada por fibras colágenas e elásticas, sendo que este fibroelástico tem o papel de ser o principal fator na geração da pressão de fechamento da uretra e da JVU em repouso. A presente revisão literária tem por objetivo descrever o sistema elástico da JVU e sua relação com o avanço da idade. Verificou-se que na JVU existe a presença de fibras elásticas maduras, elaunínicas e oxitalânicas, e que o sistema elástico da JVU não é um componente que determina o aparecimento da incontinência urinária no processo fisiológico de envelhecimento. E que o sistema elástico na região é indiretamente responsável pela continência urinária, e atua como suporte para a musculatura lisa do local, que provavelmente tem alterações mais relevantes com o avanço da idade do que o próprio sistema elástico.

The vesico-urethral junction (VUJ) is a component of the trigone of the bladder, which together with the bladder neck has important significance for fixation and positioning of the urinary bladder. The vesico-urethral junction is formed by collagen fibers and elastic, and this tissue fibroelastic has the function of being the main factor in generating the pressure to close the urethra and VUJ at rest. This literature review aims to describe the system of elastic VUJ and its correlation with advancing age. We found that in VUJ, there is the presence of mature elastic fibers, and elaunínicas oxytalan, and the system of elastic VUJ is not a component that determines the onset of urinary incontinence in the physiological process of aging. And the elastic system in the region is indirectly responsible for urinary continence, and acts as a support for the smooth muscles of the site that is probably most relevant changes with advancing age of the elastic system itself.

Effect of ionizing radiation on rat parotid gland.

A common side effect of radiotherapy used in the treatment of oral cancer is the occurrence of structural and physiological alterations of the salivary glands due to exposure to ionizing radiation, as demonstrated by conditions such as decreased salivary flow. The present study evaluated ultrastructural alterations in the parotid glands of rats receiving a fractionated dose (1,500-cGy) of radiation emitted by a Cesium-137 source and rats that were not subjected to ionizing radiation. After sacrifice, the parotid glands were removed and examined by transmission electron microscopy. Damage such as cytoplasmic vacuolization, dilatation of the endoplasmic reticulum and destruction of mitochondria, as well as damage to the cellular membrane of acinar cells, were observed. These findings lead to the conclusion that ionizing radiation promotes alterations in the glandular parenchyma, and that these alterations are directly related to the dose level of absorbed radiation. Certain phenomena that appear in the cytoplasm and nuclear material indicate that ionizing radiation causes acinar cell death (apoptosis).

Effect of ionizing radiation on rat parotid gland

A common side effect of radiotherapy used in the treatment of oral cancer is the occurrence of structural and physiological alterations of the salivary glands due to exposure to ionizing radiation, as demonstrated by conditions such as decreased salivary flow. The present study evaluated ultrastructural alterations in the parotid glands of rats receiving a fractionated dose (1,500-cGy) of radiation emitted by a Cesium-137 source and rats that were not subjected to ionizing radiation. After sacrifice, the parotid glands were removed and examined by transmission electron microscopy. Damage such as cytoplasmic vacuolization, dilatation of the endoplasmic reticulum and destruction of mitochondria, as well as damage to the cellular membrane of acinar cells, were observed. These findings lead to the conclusion that ionizing radiation promotes alterations in the glandular parenchyma, and that these alterations are directly related to the dose level of absorbed radiation. Certain phenomena that appear in the cytoplasm and nuclear material indicate that ionizing radiation causes acinar cell death (apoptosis).

Um efeito colateral comum da radioterapia usada no tratamento de câncer na cavidade oral é a ocorrência de alterações estruturais e fisiológicas sobre as glândulas salivares por exposição à radiação ionizante, como demonstrada em situações com decréscimo do fluxo salivar. O presente estudo teve por objetivo avaliar as alterações ultra-estruturais de glândulas parótidas de ratos que receberam uma dose fracionada (1500 - cGy) de radiação emitida por uma fonte de Césio 137 e ratos que não receberam a radiação ionizante. Após o sacrifício, as glândulas parótidas foram removidas e examinadas por microscopia eletrônica de transmissão. Lesões das organelas citoplasmáticas, como dilatação do retículo endoplasmático, destruição das mitocôndrias e formação das vacuolizações citoplasmáticas, além de lesão da membrana celular das células acinares foram observadas. Portanto, a radiação ionizante promove alterações no parênquima glandular, o que está diretamente relacionado com a dose de radiação absorvida. Determinados fenômenos que surgem no citoplasma e material nuclear são indicadores de que a radiação ionizante leva a célula acinar a morte programada (apoptose).

Analysis of thyroid gland microvascularization in rats induced by ingestion of potassium bromide: a scanning electron microscopy study.

The microvascularization of the thyroid gland in rats was studied in animals following ingestion of potassium bromide in various concentrations in drinking water (15, 50 or 100 mg/l) over a period of either 16 or 66 days. Accordingly, animals were divided into six study groups and one control group. Microvascularization was compared among the groups. The pattern of thyroidal follicle distribution within the blood vessels was evaluated by scanning electron microscopy. Animals that ingested potassium bromide presented an increased density and number of meshes in the capillary network of the follicle. The peripheral vessels showed flattening of the walls and in the central portion of the follicle, the distribution of the capillary network did not undergo any morphologic alteration.

New bone formation in the female rabbit tibia.

The current study aims to evaluate the new bone formation in polyvinylpyrrolidone (PVP) grafts inserted into the tibia of ten female rabbits. The animals were submitted to oophorectomy in order to induce an osteopenic condition and densitometrically analyzed at the beginning of the experiment, at three months and at seven months. During the 16 weeks of osseointegration, the animals were submitted to subcutaneous injections of three bone markers at one-week intervals, four weeks for each. Before the third densitometric analysis, the animals were sacrificed and material was collected for histological evaluation, in which osteoid formations and mineralized bone tissue were observed surrounding the grafts, even within the medullary cavity. Only small quantities of new bone were found in the osteopenic animals, indicating the high osteocondutivity of PVP and its efficacy in inducing osteopenia. Among the samples with no graft, a high level of disorganization of the material was observed in the oophorectomized group, confirming the efficacy of oophorectomy.

Structural and microvascular study of soleous muscle of Wistar rats after section of the sciatic nerve.

It is not well established yet the relationship between the activation of satellite cells and skeletal muscle microcirculation after surgical denervation. Trough scanning and transmission electron microscopy methods, we studied comparatively the alterations of the soleus muscle in Wistar rats after surgical denervation. Our results evidenced the activation, duplication and migration of satellite cells to the interior of muscle fibers coexisting with a raise in the capillary density characterized by a higher number of anastomosis and capillary sprouts. We conclude that the microcirculation plays a key role in the regenerative process.

New bone formation in the female rabbit tibia

O presente estudo constitui em se fazer uma avaliação da neoformação óssea em enxertos de PVP (polivinilpirrolidona) colocados em tíbias de dez coelhas. Os animais foram submetidos à cirurgia de ooforectomia para a indução de um quadro osteopênico e analisados densitometricamente no início do experimento, aos três meses e aos sete meses. Durante as dezesseis semanas de osteointegração, os animais foram submetidos a injeções subcutâneas de três marcadores ósseos, em intervalos semanais, por quatro semanas cada um; em seguida, foram sacrificados, previamente à terceira análise densitométrica, para avaliação histológica do material. Foi observada a presença de formações osteóides e tecido ósseo mineralizado envolvendo o enxerto, inclusive na região medular, em menor quantidade nos animais osteopênicos, o que indica a boa qualidade osteocondutora do PVP e a eficácia na indução de osteopenia pela menor quantidade de material ósseo encontrado. No material sem enxerto, observou-se um tecido mais desorganizado no grupo ooforectomizado, reiterando a eficácia da ooforectomia.

Structural and microvascular study of soleous muscle of Wistar rats after section of the sciatic nerve

Ainda não está suficientemente estabelecida a relação entre a ativação das células satélites e a microcirculação muscular, após denervação cirúrgica. Através de métodos de microscopia eletrônica de transmissão e varredura, foram estudadas comparativamente as alterações do músculo sóleo, de ratos Wistar, após sua denervação.Os resultados evidenciaram que no músculo denervado ocorre ativação, duplicação e migração das células satélites para o interior da fibra muscular, acompanhadas de aumento de densidade da rede capilar, caracterizada por maior número de anastomoses e brotamentos angiogênicos. Fica assim evidenciada a importância da microvascularização nos processos biológicos de reparação muscular.

Nutrition pathways to the symphysis pubis.

The blood supply of the symphysis pubis is still the subject of some debate. Classic anatomy books state that this joint is avascular, whereas some published works have shown blood vessels in young specimens. As several articular discs such as the knee menisci are known to have blood vessels in their peripheries, we decided to investigate the possible nutrition pathways to the interpubic disc and ligaments. We used 60 Wistar rats, male and female, aged between 28 and 32 days, or between 90 and 100 days. Samples were processed using a variety of techniques: regular histology, immunohistochemestry, India ink injection and corrosion casting. The interpubic disc consisted of an inner bearing portion and an outer fibrous rim. The interpubic ligaments and the fibrous rim were well vascularized in all groups. Marrow contacts between the interpubic disc and the subchondral bone were also observed. Blood vessels formed an authentic arterial circle embracing the joint, from which blood vessels branched into capillary loops facing the avascular inner bearing portion of the disc. These results confirm the need for future studies on the human symphysis pubis, to provide more details on its structure, which would enable clinicians such as physiotherapists to improve prognosis and treatment design. Future studies may also explain the pathways down which the hormone relaxin reaches its targets within this joint.

Histomorphometric evaluation of new bone formation in diabetic rats submitted to insertion of temporary implants.

This study aimed to quantify new bone formation in the femurs of diabetic Wistar rats. Over an eight-week period, MTI-MP implants were evaluated in control rats and in diabetic rats. At several points during this period, various markers for bone deposit were introduced. The material was observed under fluorescent light microscopy. New bone formation in periosteal and cortical regions linked to the implant did not vary significantly between the groups. However, there were significant differences in total new bone formation in the medullar canal and in bone/implant contact area in the medullar portion. Bone deposits attached to the surface of the temporary implants demonstrated that they are biocompatible and capable of osseointegration.

Histomorphometric evaluation of new bone formation in diabetic rats submitted to insertion of temporary implants

Este estudo se propôs a quantificar a neoformação óssea nos fêmures de ratos Wistar diabéticos. Implantes MTI-MP® foram avaliados por um período cicatricial de 8 semanas durante as quais foram administrados marcadores de deposição óssea. O material foi observado sob microscopia de luz fluorescente. A neoformação óssea nas regiões periostal e na cortical junto ao implante não mostraram diferença significativa entre os grupos. Essa mostrou-se significativa quando avaliado o canal medullar, na avaliação do tecido neoformado como um todo e na área de contato entre osso e implante quando analisada sua porção intramedullar. A deposição óssea analisada junto à superfície dos implantes temporários demonstrou que os mesmos são biocompatíveis e passíveis de osteointegração.

Tridimensional architecture of the collagen element in the arachnoid granulations in humans: a study on scanning electron microscopy.

The arachnoid granulations of adult individual of both sexes were studied through scanning electron microscopy. The dura mater and arachnoid meninges of individuals were collected at the Service of Death Verification of São Paulo - USP and fixed in Karnovsky solution. After this period the material was prepared for analysis in electron microscope. Our results demonstrated that the arachnoid granulations are formed by a pedicle, body and apex, being surrounded by a capsule of connective tissue, which in turn is composed of, basically, bundles of collagen fibers that line pores of different shapes and sizes. The smaller pores are lined by tiny bundles and are located at the apical region of the granulation and the larger are lined by thicker bundles and are located at the lateral regions. In the body we verified that the bundles of collagen fibers compose a fibrous meshwork and in some regions these bundles have circular orientation, forming pores similar to those found at the region of the capsule.

Tridimensional architecture of the collagen element in the arachnoid granulations in humans: a study on scanning electron microscopy

The arachnoid granulations of adult individual of both sexes were studied through scanning electron microscopy. The dura mater and arachnoid meninges of individuals were collected at the Service of Death Verification of Säo Paulo - USP and fixed in Karnovsky solution. After this period the material was prepared for analysis in electron microscope. Our results demonstrated that the arachnoid granulations are formed by a pedicle, body and apex, being surrounded by a capsule of connective tissue, which in turn is composed of, basically, bundles of collagen fibers that line pores of different shapes and sizes. The smaller pores are lined by tiny bundles and are located at the apical region of the granulation and the larger are lined by thicker bundles and are located at the lateral regions. In the body we verified that the bundles of collagen fibers compose a fibrous meshwork and in some regions these bundles have circular orientation, forming pores similar to those found at the region of the capsule

A morphometric study of age-related changes in the elastic systems of the common carotid artery and internal carotid artery in humans.

The present study aims to quantify the distribution of the elastic fiber system in the walls of the common carotid artery and the internal carotid artery in humans. In order to identify specific fibers, segments of carotid arteries were stained using the Verhoeff (for elastic fibers), Weigert (for elastic and elauninic fibers) and Weigert-oxone (for elauninic and oxytalanic fibers) methods. A histomorphometric study was undertaken in order to estimate the linear density (LV) of the fibrous components present in the elastic system and determine the total length of these components in each segment. Microscopic fields were sampled using a test system in which the colors and bands defined in the current study were superimposed on the histological preparations. Data were analyzed through linear regression using first-order rate equations and computer software. The internal carotid artery can be loosely defined as muscular in nature. In order to classify common carotid arteries, it is necessary to consider subject age. From 0 to 30 years of age, the LV of mature elastic fibers does not change significantly in either (left or right) common carotid artery, although a significant reduction in the LV of this type of fiber occurs in the right internal carotid artery. The most marked reduction in oxytalanic and elauninic fibers occurs between 0 and 10 years of age, becoming less intense between the ages of 10 and 30.

Histomorphometrical study of the elastic fiber system in the anterior cerebral artery of man

The aim of the present study was to quantify the distribution of the elastic fiber system within the wall of the anterior cerebral artery. The study is based on the works of Glynn (1940) and Stehbens (1989) concerning the incidence and origin of brain aneurysms and recent studies of the elastic fibers. The anterior cerebral artery was divided into three segments, S1, S2 and S3: S1 corresponds to the origin of the anterior cerebral artery, S2 is located at the junction of the anterior cerebral artery with the anterior communicating artery, and S3 at the junction of the rostrum and genu of the corpus callosum,which were submitted to routine histological procedures. A histomorphometrical study was undertaken using an estimation of the linear density (Ld) of the components of the fibrous elastic system which evaluates their full length in each segment. Data were analyzed using first order linear regression methods. The results show a decreasing quantity of elastic fibers in the three segments (S1>S2>S3). Study of the elastic fiber system may originate new concepts regarding the genesis of cerebral artery aneurysm

Correlation between variations in the termination of the human renal veins and the frequency of valves

Foram estudados o tronco principal e as junções cavo-renais direita e esquerda de 100 cadáveres com o objetivo de investigar as possíveis relações entre a presença de valvas e as variações na forma de terminação das veias renais. As valvas desenvolvidas não foram encontradas na veia-renal esquerda. Na veia renal direita as valvas desenvolvidas encontravam-se com maior freqüência nos casos em que a junção cavo-renal direita ocorria acima da esquerda, 10 entre 16 casos (62,5 por cento) e nos casos de veias renais direitas duplas, 14 entre 24 (58,3 por cento). Nos casos de junção cavo-renal direita ao mesmo nível da esquerda foram encontradas em 10 entre 27 casos (37 por cento) e nos casos de junção cavo-renal direita abaixo da esquerda em 07 entre 31 casos (22,6 por cento). As valvas rudimentares foram encontradas na veia renal direita em 19 casos e na veia renal esquerda em 12 casos. Os autores discutem as relações dos tipos morfológicos das valvas com o nível de terminação das veias renais na veia cava e com o ângulo formado pelas junções cavo-renais.

Morphology and incidence of valves in the facial vein of humans

Se realizó este estudio para constatar la periocidad y cantidad en que se encuentran las valvas en la vena facial. Las venas faciales, derecha e izquierda de 50 cadáveres, adultos, de sexo masculino, previamente sumergidos en formol al 10 por ciento, fueron disecadas y abiertas longitudinalmente, desde su origen hasta su desembocadura, con el fin de constatar la presencia y ubicación de las valvas. Se observaron valvas en 41 casos (82 por ciento). Estas eran bien desarrolladas y fueron clasificadas en valvas ostiales y parietales. Entre las valvas ostiales habían unicúspides y bicúspides, mientras que las parietales eran solamente bicúspides. El trecho de la vena facial que presentó el mayor número de valvas fue el que se encuentra a nivel de la glándula submaxilar. Las paredes venosas que tenían valvas, presentaban seno valvular. Las relaciones entre variaciones anatómicas, constitución de la pared venosa y la presencia de valvas, son discutidas a lo largo del presente trabajo

Meso and microscopic study of the facial vein and adjacent tissues

El objetivo de esta investigación es estudiar las relaciones de la vena facial con las estructutras adyacentes. Las venas faciales, derecha e izquierda, de 50 cadáveres, fueron disecadas bajo microscopio estereoscopio y descritas sus relaciones con estructuras vecinas. Segmentos de las venas facialesde 10 cadáveres fueron sometidos a cortes histológicos teñidos por el método de weigert modificado por Van Gieson. La vena facial, a pesar de su corto trayecto, sufre importantes variaciones en la constitución de su pared. En sus relaciones de sintopía, se relacionan con músculos, tejido adiposo y glándulas entre otros tejidos. Verificamos la existencia de fibras elásticas y colágenas, conectando la adventicia a los tejidos adyacentes, así como formando una vaina fibrosa alrededor de la vena facial , lo que probablemente protege esta vena de tracciones poroducidas durante los movimientos de las estructuras vecinas. En el trabajo también son discutidas las implicancias de la sintopía de la vena facial y de los requerimientos biodinámicos generados por el movimiento sobre la morfología de esta vena