Histo-architechtural Evaluation of Conventional Versus Two Rapid Microwave Processing Techniques.

Aims: This work aims to reduce the time of tissue processing, exclude xylene from tissue processing as well as to reduce the total quantity of reagents used per cycle of paraffin wax processing technique. Study Design: Harvesting and fixation of tissues. Grossing into triplicates, processing using three different techniques. Staining and grading of sections. Place and Duration of Study: Apparently healthy rabbits from the animal house, National Veterinary research Institute, Vom, Jos, Nigeria, between August and December, 2014. Methodology: Two apparently healthy rabbits were sacrificed and the Trachea, Lungs, Heart, Liver, Kidney, Stomach, Skin, Brain, and the Spleen were harvested and fixed in 10% buffered formalin for three days. They were grossed into triplicates, labeled and processed using the conventional, microwave without vacuum and microwave with vacuum respectively. They were sectioned and stained simultaneously using the haematoxylin and eosin staining technique as well as the Gordon and Sweet’s method. They were graded as excellent if they permitted microscopy, fair if not very good but can permit microscopy and poor if they cannot permit microscopy at all. Results: There is a drastic reduction in the duration of processing as well as the quantity of reagents used in the microwave techniques as compared to the conventional method. Xylene was completely eliminated in the microwave techniques. Tissue histo-architechture, special features as well as silver impregnation were clearly demonstrated without significant differences. Dye uptake as well as section thickness were comparable among the three techniques. Conclusion: Same-day turn-around is possible in histology, with reduced reagent consumption and elimination of xylene, without compromising section quality, dye uptake or ability to reduce silver to its metallic form. This will result to quick diagnosis hence quick intervention at a cheaper rate to both laboratories and clients. It is a good innovation in forensic and diagnostic histopathology and should be encouraged. Its compatibility with histochemical, immunohistochemical and molecular techniques should be evaluated to give a wider application.

Adaptación de la técnica de impregnación argéntica de Llombart para la demostración de fibras nerviosas, en cualquier tejido en cortes por parafina / Adaptation of Llombart's silver impregnation technique for demonstration of nerve fibers in any tissue in paraffin sections

En la investigación biológica sigue siendo necesaria la demostración de la inervación periférica en numerosos tejidos y órganos. El objetivo de este trabajo fue rescatar y modernizar uno de los métodos más constantes que hemos probado para demostrar la inervación periférica. La técnica de Llombart para fibras nerviosas se adaptó en cortes por parafina de 7 µm en diferentes tejidos animales. La impregnación argéntica se hizo por goteo en cámara húmeda. Se demostraron en forma constante, precisa y seriada terminaciones nerviosas y corpúsculos sensoriales, neuronas y fibras nerviosas periféricas. A pesar de la alta especificidad para fibras nerviosas, la técnica no compromete el panorama tisular por lo que da bellas imágenes de conjunto. Sin ser una técnica para argentafinidad, demuestra claramente dos tipos de células argentafines en las glándulas adrenales. La adición de los reactivos metálicos en gotas y en cámara húmeda, ofrece una variante sumamente económica.

In Biological research is still necessary for the demonstration of the peripheral innervation in numerous tissues and organs. The aim of this study was to rescue and modernize one of the most consistent methods that we have tried to demonstrate peripheral innervation. Llombart's technique for nerve fibers was adapted by paraffin cuts of 7 µm in different animal tissue. The silver impregnation was done by dripping in a moist chamber. It was demonstrated in a constant, precise and serial form, nerve terminations, and sensorial corpuscles, neurons, and peripheral nerve fibers. Despite being highly specific to nerve fibers, the technique does not sacrifice tissue panorama so it gives beautiful images set. Without being a technique to argentaffin structures, it clearly shows two types of argentaffin cells in the adrenal glands. The addition of the metal reactive in droplets and in a humid chamber provides a very economical variant.

Structural organization and pattern of innervations of human Meissner's corpuscle: a light microscopic study.

Background: Human glabrous skin has very rich nerve supply in the form of specialized nerve endings like Meissner’s corpuscles, Pacinian corpuscles, Krause end bulbs etc for carrying sensory information to brain. Aim of study: To study the structure, pattern of innervations and nerve terminations of human Meissner’s corpuscle. Methods: Skin samples from sixty human beings (age range 2 to 72 years) were taken, sections prepared and stained with a cytological (Haematoxylin – Eosin and Vongieson’s stains) and a neural stain (Silver Impregnation). Results: With cytological stain, Meissner’s corpuscles were seen in dermal papillae of glabrous skin, each consisting of a cellular structure having a peripheral capsule and central core of transversely arranged cells. With neural stain, each corpuscle was seen to be oval, globular or cylindrical structure, having a capsule surrounding the core of spirally arranged nerve fibers, sandwiched by Schwann cells. In between nerve fibers of the core were seen small bundles of collagen fibers. 2-6 nerve fibers innervated each Mc from the sub corial plexus of nerves and formed various patterns of nerve endings like networks, end bulbs and varicosities inside the Meissner’s corpuscle. Conclusion: Meissner’s corpuscle is a complex structure composed of capsule - consisting of spindle shaped capsular cells interspersed in collagen fibers, surrounding a core of helically arranged nerve fibers, Schwann cells and collagen fibers.

Nerve endings of filliform, fungiform and vallate papillae of dorsal tongue mucosa of White-lipped peccary (Tayassu pecari): Neurohistological observations / Terminação nervosa das papilas filiformes, fungiformes e valadas da mucosa dorsal da língua de queixada: observação neurohistológica

The neurohistologic observations were performed using the specimens prepared by Winkelmann and Schmitt silver impregnation method. The tissues were fixed in 10 percent formalin solution and sections of 40µm thickness were obtained by Leica Cryostat at -30ºC. The sections of dorsal mucosa of White-lipped peccary tongue showed numerous filliform and fungiform papillae, and two vallate papillae on the caudal part. The epithelial layer revealed queratinized epithelial cells and the connective tissue papillae of different sizes and shapes. Thick nerve fiber bundles are noted into the subepithelial connective tissue of the papillae. The connective tissue of fungiform and vallate papillae contained numerous sensitive nerves fibers bundles forming a complex nerve plexus.

As observações neuro-histológicas foram realizadas utilizando amostras preparadas segundo o método de impregnação por prata de Winkelmann e Schmitt. Os tecidos foram fixados em solução de formol a 10 por cento e seções de 40µm de espessura foram obtidas em criostato Leica -30ºC. As seções da mucosa dorsal da língua de queixada revelaram numerosas papilas filiformes, fungiformes e duas papilas valadas sobre a parte caudal. A camada epitelial revelou células epiteliais queratinizadas e papilas de tecido conjuntivo de diferentes tamanhos e formas foram observadas. Espessos feixes de fibras nervosas são notados no tecido conjuntivo subepitelial das papilas. O tecido conjuntivo das papilas fungiformes e valadas contêm numerosos feixes de nervos de fibras sensíveis formando um plexo nervoso complexo.

RESEARCH ON THE QUANTITATIVE ANALYSIS OF THE HIPPOCAMPUS—FORNIX—MAMILLOTHALAMIC SYSTEMS AND THE SPATIAL SEQUENTIAL STRUCTURE IN THE HIPPOCAMPUS OF THE RABBIT / 解剖学报

Nine adult rabbits, perfused with 10% formalin, were used in this experiment. Five of them were mounted on the stereotaxic apparatus according to the Sawyer's atlas. Brains were removed and made serial sections including thalamus and hippocampus. The neocortices of the other four rabbits were removed and the hippocampal formations were exposed. Serial sections of the hippocampus were made and stained alternately with Nissl's method and the silver impregnation method of Glees. The results could be summarized as follows.1. The hippocampus measured 28.00-36.00 mm in length, 6.00-8.50 mm in breadth and 2.68-3.39 mm in thickness. The total numbers of the pyramidal cells (CA_1-CA_4), the granular cells in the dentate gyrus and the basket cells were 7.36?10~6, 4.93?10~6, 2.40?10~5 respectively. The ratio of the total numbers among the pyramidal, granular and the basket cells was 30:20:1 approximately. The total number of the CA_1 pyramidal neurones was 4.11?10~6, and that of the CA_3 was 2.48?10~6. The ratio of the numbers of the CA_1 and CA_3 neurones was 1.66:1.2. The arrangements of the granular cells in the dentate gyrus and the apical dentrites of the CA_1 neurones were rather regular and possessed a typical array-like structure.3. The total numbers of the fibers in the column fornix (FN)and the mamillothalamic tract (MT) were 83700 and 58740 respectively. MT:FN=1:1.42. The total number of the neurones in the mamillary nucleus was 113500, and that of the anterior thalamic nucleus was 165600. The ratio of the neurones between these two nuclei was 1:1.46.According to the results mentioned above, the functional significance of the characteristic structure of the hippocampus was also discussed.