Synovium and blood capillaries at the femoral attachment of anterior cruciate ligament are significantly abundant than those at the tibial attachment / Sinovial y capilares sanguíneos en la inserción femoral del ligamento cruzado anterior son significativamente más abundantes que los de la inserción tibial

SUMMARY: The anterior cruciate ligament (ACL) is a ligament that mainly controls the anterior and rotational mobility of the knee joint, and its surface is covered by a synovial membrane with large number of blood vessels. In general, nutritional supply to the ligament is from many capillaries in the adjacent synovium. However, statistical studies of the capillaries distributed to the ACL are insufficient. In this study, we examined cross-sectional histological images of the femoral attachment (femoral level), middle level of the tendon (middle level), and tibial attachment (tibial level) of the ACL and statistically analyzed blood capillary distribution among the three levels. The ACLs of 10 cadavers were divided into 5 equal sections, and 4mm-thick paraffin sections were made at the femoral level, middle level, and tibial level, and then hematoxylin-eosin (HE) staining were performed. The area of each transverse section was measured using Image-J 1.51n (U. S. National Institutes of Health, Bethesda, MD, USA). Fiber bundles of the ACL were relatively small and sparse in cross-sectional area at the femoral level and became larger and denser toward the tibial level. Many blood levels. The synovium at the attachment of ACL covered the surface of the fiber bundle and also penetrated deeply between the fiber bundles. In particular, the blood capillaries were densely distributed in the synovium at the femoral attachment rather than another two levels. Indeed, the number of capillaries were also most abundant in the femoral level. The cross-sectional ACL area at the femoral level is significantly small, however, the blood capillaries were most abundant. Therefore, when the ACL is injured, its reconstruction with preservation of the femoral ligamentous remnant may be clinically useful for remodeling of the grafted tendon.

El ligamento cruzado anterior (LCA) es un ligamento que controla principalmente la movilidad anterior y rotacional de la articulación de la rodilla, y su superficie está cubierta por una membrana sinovial con gran cantidad de vasos sanguíneos. En general, el suministro de nutrientes al ligamento proviene de muchos capilares en la sinovial adyacente. Sin embargo, los estudios estadísticos de los capilares distribuidos en el LCA son insuficientes. En este estudio, examinamos imágenes histológicas trans- versales de la inserción femoral (nivel femoral), el nivel medio del tendón (nivel medio) y la inserción tibial (nivel tibial) del LCA y analizamos estadísticamente la distribución de los capilares sanguíneos entre los tres niveles. Los LCA de 10 cadáveres se dividieron en 5 secciones iguales y se realizaron cortes en parafina de 4 µm de espesor a nivel femoral, medio y tibial, y luego se realizó tinción con hematoxilina-eosina (HE). El área de cada sección transversal se midió utilizando Image-J 1.51n (Institutos Nacionales de Salud de EE. UU., Bethesda, MD, EE. UU.). Los haces de fibras del LCA eran relativamente pequeños y escasos en el área de la sección transversal a nivel femoral y se hicieron más grandes y más densos hacia el nivel tibial. La membrana sinovial en la unión del LCA cubría la superficie del haz de fibras y también penetraba profundamente entre entre los haces de fibras. En particular, los capilares sanguíneos estaban densamente distribuidos en la unión femoral de la sinovial respecto a los otros dos niveles. De hecho, el número de capilares también fue más abundante a nivel femoral. El área transversal del LCA a nivel femoral era significativamente pequeña, sin embargo, los capilares sanguíneos fueron los más abundantes. Por lo tanto, cuando hay una lesión del LCA su reconstrucción con preservación del ligamento femoral remanente puede ser clínicamente útil para remodelar el tendón injertado.

Microcirculatory changes as a hallmark of aging in the heart and kidney / Cambios microcirculatorios como sello distintivo del envejecimiento en el corazón y riñón

SUMMARY: Changes in the microcirculation of multiple tissues and organs have been implicated as a possible mechanism in physiological aging. In particular, vascular endothelial growth factor is a secretory protein responsible for regulating angiogenesis via altering endothelial proliferation, survival, migration, extracellular matrix degradation and cell permeability. The aim of the present study was to evaluate the role of vascular endothelial growth factor in the progression of morphological alterations caused by physiological aging in the heart and kidney and to examine its relation to changes in capillary density. We used two age groups of healthy Wistar rats - 6- and 12-month- old. The expression of vascular endothelial growth factor was examined through immunohistochemistry and immunofluorescence and assessed semi-quantitatively. Changes in capillary density were evaluated statistically and correlated with the expression of vascular endothelial growth factor. We reported stronger immunoreactivity for vascular endothelial growth factor in the left compared to the right ventricle and also observed an increase in its expression in both ventricles in older animals. Contrasting results were reported for the renal cortex and medulla. Capillary density decreased statistically in all examined structures as aging progressed. The studied correlations were statistically significant in the two ventricles in 12-month-old animals and in the renal cortex of both age groups. Our results shed light on some changes in the microcirculation that take place as aging advances and likely contribute to impairment in the function of the examined organs.

Los cambios en la microcirculación de múltiples tejidos y órganos se han implicado como un posible mecanismo en el envejecimiento fisiológico. En particular, el factor de crecimiento endotelial vascular es una proteína secretora responsable de regular la angiogénesis mediante la alteración de la proliferación endotelial, la supervivencia, la migración, la degradación de la matriz extracelular y la permeabilidad celular. El objetivo del presente estudio fue evaluar el papel del factor de crecimiento del endotelio vascular en la progresión de las alteraciones morfológicas causadas por el envejecimiento fisiológico en el corazón y riñón y examinar su relación con los cambios en la densidad capilar. Utilizamos dos grupos de ratas Wistar sanas: 6 y 12 meses de edad. La expresión del factor de crecimiento del endotelio vascular se examinó mediante inmunohistoquímica e inmunofluorescencia y se evaluó semicuantitativamente. Los cambios en la densidad capilar se evaluaron estadísticamente y se correlacionaron con la expresión del factor de crecimiento del endotelio vascular. Informamos una inmunorreactividad más fuerte para el factor de crecimiento endotelial vascular en el ventrículo izquierdo en comparación con el derecho y también observamos un aumento en su expresión en ambos ventrículos en animales mayores. Se informaron resultados contrastantes para la corteza renal y la médula. La densidad capilar disminuyó estadísticamente en todas las estructuras examinadas a medida que avanzaba el envejecimiento. Las correlaciones estudiadas fueron estadísticamente significativas en los dos ventrículos en animales de 12 meses y en la corteza renal de ambos grupos de edad. Nuestros resultados arrojan luz sobre algunos cambios en la microcirculación que tienen lugar a medida que avanza el envejecimiento y probablemente contribuyan a un deterioro en la función de los órganos examinados.

The architecture of alveolar capillaries in the lungs of bactrian camels (Camelus bactrianus) / Arquitectura de los capilares alveolares de pulmones de camellos bactrianos (Camelus bactrianus)

SUMMARY: The Bactrian camel, which is native to China and Mongolia, is large in size and is an even-toed ungulate species. The double humps on the Bactrian camel back differentiate it from the dromedary camel, which has a single hump. This species has adapted to unsuitable conditions (lack of food and water) in the Gobi Desert and is advanced in unique anatomical and physiological characteristics during a prolonged evolution period. Several studies have been conducted on the anatomical features of the Bactrian camel, but none have given attention to the alveolar capillaries of the Bactrian camel lung. Therefore, the current study aims to explore the architecture of the alveolar capillary in the Bactrian camel lung and further explain the mechanism of blood flow in its lung. The current study extracted and examined the architecture of the alveolar capillary in the lung of the Bactrian camel (Camelus bactrianus) and further explained the mechanism of blood flow by performing lung casting and replica scanning electron microscopy methods. The reports showed that the resources of the alveolar-capillary originated from the capillaries of the subpleural space or interlobular septulum, sometimes originating from the precapillary arterioles or directly from the terminal arterioles. The alveolar capillaries anastomosed and formed a single layer of dense, basket-like network surrounding the alveolus. The mash diameter of the alveolar-capillary network was larger than that of the capillary, and the appearance of the mash was oval and elliptical. Many of the collapsed alveolar-capillary networks were found in the alveolar microvascular architecture in the lung of the Bactrian camel. The study found that, due to many collapsed alveoli in the Bactrian camel lung, the disproportional pressure between the pulmonary alveoli induced less imbalance of blood flow in the alveolar capillary, which affected the gas exchange efficiency. Therefore, the function of the anastomosing capillary branch was likely to regulate the blood flow between the alveolar-capillary network.

RESUMEN: El camello bactriano, es originario de China y Mongolia, es de gran tamaño y es una especie de ungulado de dedos pares. Las dobles jorobas del lomo del camello bactriano lo diferencian del dromedario, que tiene una sola joroba. Esta especie se ha adaptado a condiciones inadecuadas (falta de alimento y agua) en el desierto de Gobi y ha avanzado en características anatómicas y fisiológicas únicas durante un período de evolución prolongado. Se han realizado varios estudios sobre las características anatómicas del camello bactriano, pero ninguno ha prestado atención a los capilares alveolares del pulmón de este animal. Por lo tanto, el presente estudio tuvo como objetivo principal explorar la arquitectura del capilar alveolar en el pulmón del camello bactriano y explicar el mecanismo del flujo sanguíneo. A partir de nuestro trabajo se examinó la arquitectura del capilar alveolar en el pulmón del camello bactriano (Camelus bactrianus) mediante la realización de métodos de microscopía electrónica de barrido y escaneo pulmonar. Los informes mostraron que los recursos del alvéolo-capilar se originaban en los capilares del espacio subpleural o del tabique interlobulillar y a veces se originaban en las arteriolas precapilares o directamente en las arteriolas terminales. Los capilares alveolares se anastomosaban y formaban una densa red de capa única en forma de cesta que rodeaba el alvéolo. El diámetro del macerado de la red alveolar-capilar era mayor que el del capilar y el aspecto del macerado era ovalado y elíptico. Muchas de las redes alvéolo-capilares colapsadas se encontraron en la arquitectura microvascular alveolar en el pulmón del camello bactriano. El estudio encontró que, muchos alvéolos colapsados en el pulmón del camello bactriano, la presión desproporcionada entre los alvéolos pulmonares inducía un menor desequilibrio del flujo sanguíneo en el capilar alveolar, lo que afectaba la eficiencia del intercambio de gases. Por lo tanto, la función de la rama capilar anastomosante probablemente regularía el flujo sanguíneo entre la red alveolar-capilar.

Coat and skin morphology of hair sheep breeds in an equatorial semi-arid environment.

This study aims to address if are there annual changes in the hair coat traits and skin morphology of hair sheep breeds raised in an equatorial semi-arid region? Coat and skin samples were taken from thirty Morada Nova (4 ±â€¯2 years old; red coat; ±SD) and twenty Santa Inês multiparous ewes (5 ±â€¯2 years old; brown and black coat; ±SD) every 3 months over a year. Hair coat traits included thickness (mm), density (number of hairs cm-2), length (mm), and diameter (mm), plus epidermal and dermal thickness (µm), sweat glands and blood capillaries area (µm cm-2) were determined. Means of solar irradiance and ambient air temperature were higher between September and December. Annual changes (P < 0.05) in hair density, diameter, length and thickness, as well as the skin blood capillaries and sweat gland area differed between breeds. The modifications on hair coat traits resulted in minor changes on the effective thermal conductivity of the hair coat surface both for Morada Nova and Santa Ines sheep. Nevertheless, it was clearly evident that the overall cutaneous thermal insulation for Morada Nova sheep was lowest in September that was coupled with lower hair density, coat thickness, and higher sweat gland and blood capillary area (P < 0.05). In conclusion, even in an equatorial region, phenotypic acclimatization on morphological traits of cutaneous surface and skin traits can modify the overall thermal insulation of sheep breeds.

Nailfold videocapillaroscopy in healthy children and adolescents: description of normal patterns.

OBJECTIVES: to describe normal patterns of nailfold videocapillaroscopy (NVC) in healthy children and adolescents; to quantify the relationship between age and capillary dimensions, intercapillary distance and number of capillaries/mm; to evaluate the inter and intraobserver concordance. METHODS: Cross-sectional study including 100 healthy participants aged 5 to 18 years. Capillary dimensions (capillary loop length, capillary width and intercapillary distance) and number of capillaries/mm were evaluated in 900 capillaries using stereomicroscope under 100x magnification. Intra and inter observer agreements were tested. RESULTS: The capillary dimensions (mean ± SD) were: capillary loop length 278.6±60.3 µm, intercapillary distance 124.1±28.1 µm, capillary width 15.0±2.6 µm. Teenagers between 15 and 18 years had longer and more enlarged capillaries than the other age groups (p<0.001 and p=0.012 respectively). We also found a significant increase in the number of capillaries/mm with age (p<0.001). There was a positive correlation between age and number of capillaries/mm, capillary length, and capillary width (p<0.001, R=0.796; p<0.001, R=0.368; p=0.004, R=0.285, respectively). There was a good intra and interobserver concordance. Enlarged capillary and avascular areas were present in 11% and 10% of capillaries respectively. A weak negative correlation was found between the intercapillary distance and the number of capillaries/mm (p=0.05; R=-0.20). CONCLUSIONS: There is a wide variability in the capillary morphology among healthy individuals. There was a positive correlation between age and number of capillaries/mm, capillary length, and capillary width. In addition, NVC has been shown to be a reproducible method.

Microvascularization of corpus luteum of bovine treated with equine chorionic gonadotropin.

This study aimed to evaluate the morphological changes in microvascular density and corpus luteum (CL) vascularization in cows treated with eCG during stimulatory and superovulatory protocols. Sixteen cows were synchronized and divided into three groups: control (n = 6), stimulated (n = 4) and superovulated (n =6), one was submitted to estrous synchronization (ES) and received no eCG (control), and those that were submitted to ES and received eCG before or after follicular deviation (superovulation and stimulation of the dominant follicle, respectively). Ovulation was synchronized using a progesterone device-based protocol. After six days of ovulation, the cows were slaughtered and the ovaries and CL were collected. The CLs were processed and photomicrographs were taken under light microscopy to assess the vascular volume density (Vv) by stereology, and scanning electron microscopy (SEM) was used to perform ultrastructural analysis of the microvasculature. The Vv in stimulated and superovulated cows significantly increased (P ≤ 0.0001) when compared to control, indicating that the eCG is able to induce angiogenic activity in bovine CL. However, no significant differences were observed between stimulated and superovulated cows. The SEM demonstrated ratings indicative of angiogenesis, marked by several button-shaped projections in the capillaries, and the presence of more dilated capillaries in CL treated with eCG. These morphological findings are evidence of an angiogenic effect of the eCG treatment in CL of cows.

Comparação entre os métodos laboratorial e portátil na análise da glicemia em felinos com amostras de sangue venoso central e capilar / Comparison between the laboratory and portable methods in the glycemic analysis in cats with central venous and capillary blood samples

The objective of this study was to compare the efficacy of portable blood glucose measurement method in relation to the laboratory reference method, using central venous and capillary blood samples from 20 cats. The value obtained by the laboratory method using central venous blood sample was considered as the standard reference value. Other two values were obtained from the portable blood glucose meter, in which a sample from the same central venous blood and another one sample from capillary blood were used. For the 20 cats, the blood glucose results obtained by the laboratory method had an average of 80mg/dL; and the results found by the glucometer had an average of 84.1mg/dL with central venous blood and of 73.1mg/dL with capillary blood. The glycemic averages obtained by the glucometer with both blood samples compared to that achieved by the laboratory method resulted in variations below the maximum established (20%) by associations that regulate portable glucometers and by the organization for standardization, as well as the variation between the glycemic averages obtained by the glucometer using different blood samples. In the comparative analysis, there was no significant difference between the methods (p 0.05). In conclusion, the portable glucometer is effective in measuring blood glucose in cats, both from central venous blood and capillary blood samples.(AU)

Objetivou-se comparar a eficácia do método portátil de mensuração glicêmica com o método laboratorial de referência, utilizando-se amostras de sangue venoso central e de sangue capilar de 20 felinos. Considerou-se como valor padrão de referência o obtido pelo método laboratorial a partir de amostra de sangue venoso central. Outros dois valores foram obtidos por glicosímetro portátil, sendo utilizada amostra do mesmo sangue venoso central e outra amostra a partir de sangue capilar. Para os 20 felinos, os resultados glicêmicos verificados pelo método laboratorial tiveram média de 80mg/dL; e os resultados constatados pelo glicosímetro, média de 84,1mg/dL com sangue venoso central e 73,1mg/dL com sangue capilar. As médias glicêmicas obtidas pelo glicosímetro com ambas as amostras de sangue em relação à alcançada pelo método laboratorial resultaram em variações inferiores à máxima instituída (20%) por órgãos reguladores de glicosímetros e por entidade de padronização, bem como a variação entre as médias glicêmicas obtidas pelo aparelho com as distintas amostras de sangue. Na análise comparativa houve diferença significativa entre os métodos (p 0,05). Concluiu-se que o glicosímetro portátil é eficaz para mensuração da glicemia em felinos, tanto a partir de amostras de sangue venoso central como de sangue capilar.(AU)

Comparação entre os métodos laboratorial e portátil na análise da glicemia em felinos com amostras de sangue venoso central e capilar / Comparison between the laboratory and portable methods in the glycemic analysis in cats with central venous and capillary blood samples

The objective of this study was to compare the efficacy of portable blood glucose measurement method in relation to the laboratory reference method, using central venous and capillary blood samples from 20 cats. The value obtained by the laboratory method using central venous blood sample was considered as the standard reference value. Other two values were obtained from the portable blood glucose meter, in which a sample from the same central venous blood and another one sample from capillary blood were used. For the 20 cats, the blood glucose results obtained by the laboratory method had an average of 80mg/dL; and the results found by the glucometer had an average of 84.1mg/dL with central venous blood and of 73.1mg/dL with capillary blood. The glycemic averages obtained by the glucometer with both blood samples compared to that achieved by the laboratory method resulted in variations below the maximum established (20%) by associations that regulate portable glucometers and by the organization for standardization, as well as the variation between the glycemic averages obtained by the glucometer using different blood samples. In the comparative analysis, there was no significant difference between the methods (p 0.05). In conclusion, the portable glucometer is effective in measuring blood glucose in cats, both from central venous blood and capillary blood samples.

Objetivou-se comparar a eficácia do método portátil de mensuração glicêmica com o método laboratorial de referência, utilizando-se amostras de sangue venoso central e de sangue capilar de 20 felinos. Considerou-se como valor padrão de referência o obtido pelo método laboratorial a partir de amostra de sangue venoso central. Outros dois valores foram obtidos por glicosímetro portátil, sendo utilizada amostra do mesmo sangue venoso central e outra amostra a partir de sangue capilar. Para os 20 felinos, os resultados glicêmicos verificados pelo método laboratorial tiveram média de 80mg/dL; e os resultados constatados pelo glicosímetro, média de 84,1mg/dL com sangue venoso central e 73,1mg/dL com sangue capilar. As médias glicêmicas obtidas pelo glicosímetro com ambas as amostras de sangue em relação à alcançada pelo método laboratorial resultaram em variações inferiores à máxima instituída (20%) por órgãos reguladores de glicosímetros e por entidade de padronização, bem como a variação entre as médias glicêmicas obtidas pelo aparelho com as distintas amostras de sangue. Na análise comparativa houve diferença significativa entre os métodos (p 0,05). Concluiu-se que o glicosímetro portátil é eficaz para mensuração da glicemia em felinos, tanto a partir de amostras de sangue venoso central como de sangue capilar.

Reliability and validity of digital assessment of perifoveal capillary network measurement using high-resolution imaging.

BACKGROUND: Assessment of the perifoveal capillary network (PCN) might indicate macular function and could reflect the systemic microcirculation. The quantification and reliability of this measurement is currently unknown. The aim of this study was to validate quantification of the PCN by a non-invasive technique from high-resolution retinal images. METHODS: Ten healthy volunteers were included in this validation study. At least 320 high-resolution retinal images were used for assessment of inter- and intra-observer reliability. Non-invasive capillary perfusion mapping was performed using a retinal function imager. After the images were enhanced and segmented, the reproducibility was verified by comparing the values of two independent examiners and of a single examiner at two different time points. RESULTS: The inter-observer concordance coefficients were highly significant for PCN (intraclass correlation coefficient (ICC)=0.901, 95% CI 0.655 to 0.975, p<0.001) and normalised PCN (ICC=0.727, 95% CI 0.262 to 0.923, p=0.004). The intra-observer measurements at two different time points were also highly concordant for PCN (ICC=0.879, 95% CI 0.598 to 0.968, p<0.001) and for normalised PCN (ICC=0.960, 95% CI 0.851 to 0.990, p<0.001). CONCLUSIONS: The reliability of PCN measurement is reproducible and could be used as a new tool to quantify the capillary perfusion network of the macular area.

Microcirculatory effects of intravenous fluids in critical illness: plasma expansion beyond crystalloids and colloids.

PURPOSE OF REVIEW: Plasma expanders are reviewed to determine their ability to restore microvascular function as a means for extending the transfusion trigger and delaying the use of blood transfusions. This outcome is currently achievable because of the emergence of a new understanding of optimal tissue function that prioritizes maintenance of functional capillary density, which results from the normalization of blood viscosity via the increase in plasma viscosity with new viscogenic colloids. RECENT FINDINGS: Use of viscous plasma expanders in experimental models of extreme hemodilution, hemorrhagic shock and endotoxemia shows that the limiting factor in anemia is not oxygen-carrying capacity but the decline of microvascular function due to the lowering of functional capillary density. In support of this hypothesis, we find that viscogenic colloids including high-molecular-weight starches, dextrans, polyvinylpyrrolidone, keratin and polyethylene glycol-conjugated albumin maintain or restore microvascular function in extreme hemodilution, polyethylene glycol-conjugated albumin yielding the best results. SUMMARY: Preclinical studies show that polyethylene glycol-conjugated albumin at concentrations in the range of 2-4% extends the transfusion trigger, providing the more extended and complete microvascular and systemic recovery from hemorrhagic shock, extreme hemodilution and endotoxemia, postponing the need of reestablish intrinsic blood oxygen-carrying capacity to hemoglobin concentrations lower than those associated with accepted transfusion triggers.

Placentation in dolphins from the Amazon River Basin: the Boto, Inia geoffrensis, and the Tucuxi, Sotalia fluviatilis.

A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion. The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.

Structural features of forming and developing blood capillaries of the enamel organ of rat molar tooth germs observed by light and electron microscopy.

The process of vascularization of the enamel organ, a unique epithelial structure, occurs when the tooth germ is fully developed, i.e., at the onset of dentinogenesis. Although the three-dimensional organization of the capillaries has been previously investigated, the structural features underlying the formation of the new capillaries remains poorly understood. Thus, in the hope of better understanding the mechanism of formation of the stellate reticulum capillaries, upper first molar tooth germs of newborn and 3-day-old rats were fixed in glutaraldehyde-formaldehyde and processed for light and electron microscopy. Our results showed that blood capillaries are initially in close proximity to the outer enamel epithelium. Between and intercalated with the capillaries are round/ovoid clusters of cells, some of which are vacuolated, closely apposed to the outer enamel epithelium. The outer enamel epithelium is not a continuous layer, but exhibits gaps between the cells. This suggests that the capillaries penetrate the enamel organ through these gaps, since no invagination of the epithelium was observed. The presence of a cluster of cells containing vacuoles suggests that vasculogenesis is taking place. Images showing loss of the basal lamina, proliferation of endothelial cells, presence of filopodia and lateral sprouting suggests that angiogenesis is also occurring. Thus, neoformation of capillaries of the molar enamel organ of rat seems to occur simultaneously by mechanisms of vasculogenesis and angiogenesis.

Estudo comparativo do envelhecimento do sistema capilar dos músculos: diafragma e reto anterior do abdome em ratos. Futuro modelo para o estudo de atividade física? / A comparative study on the aging process of muscles' capillary system: diaphragm and rectus abdominis in rats. A future model for physical activity studies?

No presente estudo as alterações etárias no sistema capilar foram investigadas nos músculos diafragma e reto anterior do abdome em ratos de 1, 8 e 18 meses de idade. Os padrões de ativação destes músculos diferem em que o diafragma é regularmente mobilizado muitas vezes a cada minuto durante toda a vida do animal, enquanto o reto anterior do abdome, embora mobilizado na respiração seja ativado de maneira muito menos freqüente e regular. As fibras musculares foram pré-incubadas em pH 4,35 e fixadas pelo método de Padykula e Herman para estudar a atividade miofibrilar da ATP-ase, tornando possível a separação das fibras em três grupos: oxidativa lenta (I); glicolítica oxidativa rápida (IIA) e oxidativa rápida (IIB) e a identificação dos capilares ao redor das fibras no mesmo corte. A relação capilar/fibra e a densidade capilar foram obtidas. A análise da relação capilar/fibra e da área entre os dois tipos musculares mostrou padrões diferentes de desenvolvimento capilar, no envelhecimento, das fibras não fatigáveis (I e IIA) do músculo diafragma em comparação com o reto anterior do abdome. Estas diferenças etárias do diafragma e reto anterior do abdome poderiam estar relacionadas à contínua contração diafragmática e poderia vir a ser este um modelo natural de exercício permanente e envelhecimento muscular.

Light microscopy and computer three-dimensional reconstruction of the blood capillaries of the enamel organ of rat molar tooth germs.

We performed a light microscope and a computer three-dimensional reconstruction study of serial sections of the molar enamel organ of 3- and 5-day-old rats perfused with Indian ink through the arterial system. The tooth germs were fixed in Bouin's solution, embedded in paraffin, sectioned and stained with haematoxylin and eosin. For the three-dimensional reconstruction, light micrographs of the serial sections were digitized, and aligned using the serial EM Align software downloaded from http://synapses.bu.edu/tools/. After alignment, the boundaries of the India-ink-filled blood vessels were manually traced with a mouse using the software IGL trace (version 1.26b), also downloaded from the above website. After tracing, a three-dimensional representation of the blood vessel contours was generated in a VRML format and visualized with the help of the software Cortona Web3D viewer (version 4.0) downloaded from http://www.parallelgraphics.com/products/cortona/. Our results showed that in regions where ameloblasts are polarized the capillaries are arranged in three distinct levels: (1) penetrating and leaving capillaries in relation to the outer enamel epithelium; (2) capillaries crossing and branching inside the stellate reticulum; and (3) capillaries branching and anastomosing profusely within the stratum intermedium, thereby forming an extensive capillary plexus intimately associated with the cells of the stratum intermedium. The existence of a conspicuous capillary plexus intermingled with cells of the stratum intermedium, as shown in our results, suggests that some molecules produced by cells of the stratum intermedium could be released into the capillary plexus and thereafter carried to the dental follicle.

Nail fold capillaroscopy: normal findings in children and adolescents.

OBJECTIVES: Capillaroscopy is a simple diagnostic method that permits noninvasive in vivo study of the capillary network. Studies designed to standardize capillary normality in children are limited. This article presents the capillaroscopic findings in healthy children and adolescents, thus making the application of this methodology viable for patients in this age range. MATERIAL AND METHODS: Healthy children were recruited from a private elementary school and junior high school. Nail fold capillaroscopy was performed using a stereomicroscope at 16 times magnification, addressing the following parameters: capillary morphology, capillary enlargement, devascularization, microhemorrhage, and subpapillary venous plexus visibility (PVS). These parameters were related to age, sex, ethnicity, and local periungal conditions. RESULTS: The sample comprised 329 individuals with mean age of 8.2 years. We observed atypical capillary morphology in 118 of the studied cases (36%), mainly bizarre capillaries in 90 (27%), meandering capillaries in 32 (10%), and bushy capillaries in 20 (6%). The enlarged capillary phenomenon was uncommon, being observed in 30 cases (9%). The number of capillaries per millimeter varied from five to nine. Deletion areas were detected in only seven individuals (2%). The subpapillary venous plexus was not visualized in 13 (4%) cases. Younger children presented higher PVS scores and fewer capillaries/mm as compared with older children. PVS scores were lower in males and in nonwhite children. Other variables were not associated with sex or ethnicity. CONCLUSIONS: The normal nail fold capillary network in children resembles that observed in adults with some differences, such as a lower number of loops per millimeter, a higher PVS score, and a higher frequency of atypical loops. This information is important for the diagnostic evaluation of children in the context of autoimmune rheumatic diseases.

Inactivity changed fiber type proportion and capillary supply in cat muscle.

The effect of different levels of activity on fiber types, capillaries and enzymes of gastrocnemius and soleus muscles was studied in two groups of cats. The first group was successfully kept in a large room, exercised on a treadmill 15 min daily 5 days per week and kept in individual small cages. Each period lasted 6 weeks. A muscle biopsy was taken after each period. The second group was formed by cats that were caged for over 20 months. In the group caged for over 20 months, gastrocnemius muscle showed higher IIB and lower I fiber type proportion. Fiber cross-sectional area was not different in any condition. All capillary measurements were significantly lower in gastrocnemius muscle of long-term caged cats, and capillaries per mm2 were lower in soleus muscle of these cats. Exercise increased capillary/fiber in soleus muscle but subsequent caging did not reduced it. In soleus muscle, beta-hydroxy-acyl-CoA dehydrogenase levels decreased after the cage period and hexokinase levels increased after the exercise and decreased after the cage period. In conclusion, different levels of activity for short time produced enzyme changes in soleus muscle, whereas long-term inactivity changed fiber type proportion in gastrocnemius muscle and reduced capillary supply.

Peripheral retinal vasculature in normal Jamaican children.

A prospective study of the peripheral retinal vasculature in a Jamaican cohort of subjects with sickle cell disease has been in progress over a period of 12 years using fluorescein angiography. Various vascular patterns were identified but their significance was unclear since no comparable records were available in subjects of a similar age with normal (AA) haemoglobin genotype. Fluorescein retinal angioscopy and angiography have been performed in 76 haemoglobin AA controls participating in the cohort study. The peripheral retinal capillary bed could be seen and photographed in a limited portion of the temporal peripheral fundus in a majority of this group, and there was considerable variation in the vascular pattern which could be characterised. These observations allow deviations from normal to be identified in the retinal vasculature in subjects with sickle cell disease.

Peripheral retinal vasculature in normal Jamaican children

A prospective study of the peripheral retinal vasculature in a Jamaican cohort of subjects with sickle cell disease has been in progress over a period of 12 years using flourescein angiograpphy. Various vascular patterns were identified but their significance was unclear since no comparable records were available in subjects of a similar age with normal (AA) haemoglobin genotype. Fluorescein retinal angioscopy and angiography have been performed in 76 heamoglobin AA controls participating in the cohort study. The peripheral retinal capillary bed could be seen and photographed in a limited portion of the temporal peripheral fundus in a majority of this group, and there was considerable variation in the vascular pattern which could be characterised. These observations allow deviations from normal to be identified in the retinal vasculature in subjects with sickle cell disease (AU)