Animal models of osteoarthritis: characterization of a model induced by Mono-Iodo-Acetate injected in rabbits.

Knee Osteoarthritis is a considerable public health concern, both in terms of life quality and treatment financial impacts. To investigate this disease, animal models are deemed a promising alternative. In fact, although a perfect model is generally farfetched, the creation of models that simulate human disease as accurately as possible remains an important research stake. This study aims to highlight the usefulness of the model induced by injected Mono-Iodo-Acetate and to standardize it for the rabbit species. Osteoarthritis was induced by an infra-patellar injection of 0.2 ml of an MIA solution in the left knee of 24 female New Zealand rabbits. The right knee served as a control by receiving an injection of physiological serum. The rabbits were divided into 4 groups of 6 individuals each according to the dose of MIA received per knee. All rabbits were euthanized 30 days after the injection. After sacrifice, the knees were carefully dissected and macroscopic and microscopic scores of cartilage, meniscal and synovial lesions were attributed to each group. Our study followed the laboratory animal care and management guideline published in 2017 by the Canadian Council of Animal Care. The control knees of all rabbits showed no macroscopic or microscopic lesions. The macroscopic lesions: osteophytes, meniscal lesions, fibrillation and erosion of the cartilage and microscopic lesions: disorganization of the chondrocytes, decrease in proteoglycans and synovial inflammation clinically diagnosed in human pathology were all detected and were similarly reproducible among the knees of the same group. Through this work, we highlighted the merits of the arthritis model induced by MIA, namely its simulation of several aspects of human pathology. Further advantages are low cost, speed, reproducibility. This model notably avoids delicate and risky surgical operations.

Immunohistochemical Characterization of Human Synovial Bursa Cells by Light and Transmission Electron Microscopy: Where do These Cells Come From? / Caracterización Inmunohistoquímica de las Células de la Bolsa Sinovial Humana Através de Microscopías de Luz y Transmisión: ¿De dónde Provienen esas Células?

In the present study human synovial bursa specimens were examined by light and transmission electron microscopy. For light microscopical investigation the bursa tissue was stained with azan, haematoxylin-eosin and monoclonal antibodies (CD14, CD33, CD36, CD68, laminin). For electron microscopical investigation the bursa specimens were fixated with Karnovsky's solution and 1,5% osmium tetroxide (Os0(4)) in water distilled and contrasted with 5% uranylacetate and embedded in Epon®. For the first time the antigenic phenotype was characterized and conclusions were drawn about the origin of the synovial bursa cells. Histologically the bursa was divided in two distinct layers; the intima, which is formed by a lining layer and a lamina propria, and a subintimal layer. The intima consisted of macrophage like (type I) and fibroblast like cells (type II). According to the immunohistochemical staining and the electron microscopy the type I cell seemed to be a bone marrow derived monocyte and the more frequently seen type II cell was derived from subintimal fibroblasts. The intimal bursa cell frequently interdigitated and usually communicated by their filopodia (indirect cell-cell-communication). Neither tight or gap junctions nor desmosomes could be documented. Although there was no evidence for the existence of a basal lamina, a concentration of extracellular matrix components beyond the bursa cells was observed. In our study there was no accumulation of laminin around the bursal cells, but striking was a vascular bundle of the intima subintima border zone, which was positive for laminin and CD68 and separated the intima from the subintima. In our opinion this histological structure plays an important role in the regeneration of the lining cells and acts like a barrier between bursa and blood.

En el presente estudio se examinaron bolsas sinoviales humanas a través de microscopía de luz y electrónica de transmisión. Para la microscopía de luz, el tejido de las bolsas se tiñó con Azan, H-E y anticuerpos monoclonales (CD14, CD33, CD36, CD68, laminina). Para la microscopía electrónica las bolsas fueron fijadas con solución de Karnovsky y tetróxido de osmio al 1,5% (Os04) en agua destilada y contrastada con acetato de uranilo al 5% y embebido en Epon®. En primera instada, el fenotipo antigénico fue caracterizado, concluyéndose acerca del origen de las células que componen la bolsa sinovial. Histológicamente la bolsa fue dividida en dos capas distintas - la íntima - la cual es formada por una capa lineal y una lámina propia, y, una subintima. La íntima consistió en células parecidas a macrófagos (Tipo I) y células semejantes a fibroblastos (Tipo II). De acuerdo a la tinción inmunohistoquímica y a la microscopía electrónica, las células tipo I parecen provenir de la médula ósea derivada de monocitos y el más frecuente tipo celular II fue derivadado de los fibroblastos de la subintima. Frecuentemente las células de la íntima de la bolsa se interdigitaban y usualmente se comunicaban a través de sus prolongaciones (comunicación célula indirecta-célula). No se observaron ni uniones abiertas, ni cerradas, ni desmosomas. Aunque no hubo evidencia de la existencia de una lámina basal, se observó una concentración de componentes de matriz extracelular más allá de las células de la bolsa. No hubo acumulación de laminina alrededor de estas células, pero destacada era una banda vascular de la zona límite entre íntima y subintima, la cual fue positiva para laminina y CD68 la cual separaba la íntima de la subintima. En nuestra opinión esta estructura histológica juega un importante rol en la regeneración de las células lineales y actúa como una barrera entre la bolsa y la sangre.

Variation among giant rice bodies: report of four cases and their clinicopathological features.

OBJECTIVE: To report four cases of rice bodies (RBs) showing remarkable size variations and discuss their pathogenesis. DESIGN AND PATIENTS: Based on analysis of the clinical data, we speculate on the pathogenesis of RBs using immunohistochemical and ultrastructural methods. The patients comprised three men and one woman, three with RBs in the subacromial bursae and one in the wrist synovial sheath, aged 28 (woman), 44, 50 and 81 (wrist) years, respectively. RESULTS: There were no particular differences in clinical data among the patients. T2-weighted MR imaging was very useful for diagnosis of the RBs, allowing their clear delineation from the bursal fluid. The RBs consisted of a layered protein- aceous substance with vague targetoid cut surfaces. Much fibrin and a lesser amount of collagen fibers were recognized together with various mononuclear cells, which were few in number and predominantly T cells. The bursae and synovial sheath had multiple fibrinoid spheroids at the luminal surface. CONCLUSION: Fibrinoid nodular deposits probably became detached, forming the nuclei of RBs and growing to a giant RB 65 mm in diameter.

Neurohistology of the subacromial space.

Subacromial decompression is one of the most commonly performed shoulder procedures. Debridement of the subacromial soft tissues is a critical part of the procedure. However, the extent of soft tissue debridement is not well defined. The purpose of this study was to identify neural elements within the soft tissues composing the subacromial space. Using special immunohistochemical stains and electron microscopy, neural elements were identified within the subacromial bursa, rotator cuff tendon, biceps tendon and tendon sheath, and transverse humeral ligament. There was a significantly richer supply of free nerve fibers in the bursa compared with the other tissues. The nociceptive information relayed by these fibers may be responsible for the pain associated with impingement syndrome.

[Scanning electron microscopy of the synovial membrane of the distal phalangeal joint and the navicular bursa in horses]. / Rasterelektronenmikroskopische Untersuchungen zur Synovialmembran an Hufgelenk und Bursa podotrochlearis beim Pferd.

20 extremities of horses were used to investigate the synovial membrane of the distal interphalangeal joint and the navicular bursa. From each extremity five specimens were taken from the distal interphalangeal joint capsule, two further from the navicular bursa. Synovial villi were found near the articular cartilage as well as everywhere where the joint capsule did not form a tight periostal cover or was not connected with ligaments or tendons. Some lay between the articular surfaces of the phalanx media and phalanx distalis. Besides synovial villi and synovial folds "trabecular-like" cords of synovial membrane were demonstrated in the dorsal recess of the distal interphalangeal joint. These extend from one side of synovial membrane to another but they do not have a free ending. The surface of the synovial membrane and the arrangement of several synovial structures are documented.

The synovial structure of breast-implant-associated bursae.

Over 2 million silicone breast prostheses have been implanted since they were introduced in the 1960s. After implantation, a fibrovascular tissue reaction referred to as a "capsule" is observed. Many consider this capsule to be a static structure, an effective barrier to the egress of foreign material. However, reports documenting the presence of silicone within lymph nodes of patients with apparently unruptured implants indicate that silicone may be transported away from the breast-implant capsule. To characterize the cells making up the breast-implant capsule, 183 capsules from 103 ruptured or bleeding implants and 80 intact implants were studied. Gross and light microscopic studies were performed on all, and selected capsules were subjected to ultrastructural study and Fourier-transform infrared spectroscopy. Light microscopic examination of the capsule revealed an organized, layered structure with an associated network of endothelia-lined spaces. The capsules varied in cellularity, depending on the type and integrity of the implant. The superficial cell layer of all capsules had cytoplasmic processes directed toward the surface. These long cytoplasmic processes contained vacuoles ultrastructurally, indicating phagocytic and pinocytotic capability. These cells bore immunological markers of bone marrow derived macrophage-type cells. The extracellular matrix of the surface layer consisted of an amorphous fibrillar protein lacking the ultrastructural periodicity of mature collagen. No cell-to-cell junctions were observed. Deeper capsular layers were characterized by fibroblast-type cells in a collagen matrix. No capsules studied contained basement membrane or basal lamina between the stroma of the capsule and the surface cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Equine synovial tendon sheaths and bursae: a transmission electron microscope study.

A transmission electron microscope study was undertaken to investigate the details of the synovial tendon sheath and bursal lining in horses. The lining cells appeared to be fibroblasts and were buried in a finely granular ground substance. Generally these cells had poor cytoplasmic organelles, sparse short profiles of rough endoplasmic reticulum (RER), few scattered ribosomes and, occasionally, a poorly developed Golgi complex. However, a few lining cells appeared more active, having pronounced RER with dilated cisternane. The surface of the lining cells, particularly those with dilated RER, had filipodia of different shapes, which in some instances appeared to surround a detached matrix. This feature might indicate that these cells are capable of phagocytosis. In young animals, the lining was more or less akin to that of the adult. However, the lining cells were virtually indistinguishable from the fibroblasts in the subconnective tissue.

Equine synovial tendon sheaths and bursae: an histological and scanning electron microscopical study.

The structure of equine synovial tendon sheaths and bursae has been examined by light and scanning electron microscopy. Tissue samples were obtained from horses of various types and ages with no clinical evidence of sheath or bursal disorders. The interior of both structures was lined by a cellular layer superimposed on a vascular zone supported by a fibrous layer. The pattern of cell distribution of the lining varied from site to site within the same structure depending on the nature of the underlying tissue and on the amount of movement to which the structure was subjected. The cellular layer was predominantly fibrous in nature with scanty, widely separated fibroblasts (eg where it lines the palmar ligament, tendons and paratendons). In the mesotendon and bursal extremities, where the lining is subjected to a positive degree of movement, the cellular layer was areolar in type with well established folds populated by abundant cells oval to round in shape. In foals and yearlings, the supportive layer was mainly around the areolar with patches of adipose tissue; which were gradually replaced by fibrous tissue as the animal grew.

Amyloid deposits in surgically removed articular and periarticular tissue.

In tissue from 13 of 30 patients subjected to meniscectomy, amyloid degeneration was found to varying extent along the surface of the meniscus. Tissue from 30 synovectomies, 30 bursectomies and 30 ganglia showed amyloid deposits in four, six and eight cases, respectively. Amyloid was found significantly more frequently in older patients, but there was no sex difference and no relation to duration of the symptoms or to other histological changes in the tissue. Micro-deposits of amyloid in joint tissue and tissue neighbouring joints are a frequent finding, especially in elderly persons, but the clinical significance of this finding is not clear.

Bursal fat necrosis as the presenting manifestation of pancreatic disease: light and electron microscopic studies.

Bursal swelling with inflammatory lipid laden creamy appearing bursal fluid is described in an alcoholic patient with pancreatitis. Joints swollen at the same time had clearer effusions. Morphologic and biochemical studies support the necrotic bursal membrane as the source for the synovial fluid lipids.

Ultrastructure of the subacromial bursa in painful shoulder syndromes.

In order to determine if inflammation of the subacromial bursa or "bursitis" is as common an occurrence as believed in painful conditions of the shoulder, eight bursae were obtained during surgery from 3 cases of calcifying tendinitis, 2 of tight coracoacromial ligament, 2 of rotator cuff tear and 1 of acromioclavicular osteoarthritis. In the cases of calcifying tendinitis, tight coracoacronial ligament and rotator cuff tear the morphological changes mainly consisted of a numerical increase in cells throughout the bursal wall along with proliferation of endothelial cells in the vascular channels. All of the cells including the endothelial had densely packed, intermediate type filaments in their cytoplasm but no appreciable diminution of metabolic organelles. Lipid droplets were abundant in the extracellular connective tissue of the bursae from the cases with rotator cuff tear. In contrast to the other cases, the bursa from the case of acromioclavicular osteoarthritis showed widespread fibrin deposition in association with cell necrosis. In none of the cases did inflammatory leukocytic cells infiltrate bursal tissue. We conclude, that the subacromial bursa tends to undergo proliferative or degenerative changes in rotator cuff tendinopathies but bursal inflammation with polymorphonuclear cell infiltrate does not occur commonly.

Apatite-associated arthropathy: a clinical study of 14 cases and of 2 patients with calcific bursitis.

Fourteen cases of acute calcific periarthritis and 2 cases of acute calcific bursitis are described. All patients had radiologic periarticular calcific deposits. Synovial fluid was available from 8 patients. Hydroxyapatite crystals were positively identified in 1 by x-ray diffraction analysis and by scanning and transmission electron microscopy. Apatite-associated arthropathy likely represents a form of crystal-induced inflammation. Three articular syndromes can be recognized; acute calcific periarthritis, acute (calcific) arthritis and a subacute-to-chronic arthritis resembling osteoarthritis. To improve patient classification, diagnostic criteria are proposed.

[Recessus and ganglia (author's transl)]. / Recessus und Ganglien. Ein rasterelektronenmikroskopischer Vergleich.

Preparated, communicating Recessus - Bursa suprapatellaris, Recessus popliteus and Bursa musculi gastrocnemii medialis - will be compared with ganglia. The surfaces document conformity. The REM-controls show a further proof of the gangliagenesis from recessus.

Gastrocnemio-semimembranosus bursa and its relation to the knee joint. I. Anatomy and histology.

The gastrocnemio-semimembranosus bursa and its relation to the knee joint was investigated in an autopsy material. Arthrography, dissection and microscopy were performed. The area between the joint and the bursa is described. The frequency of communicating bursa is higher in older individuals and this is due to degeneration of the joint capsule.