Conditioned saccharin avoidance induced by infusion of amphetamine in the nucleus accumbens shell and morphine in the ventral tegmental area: behavioral and biochemical study.

Drugs of abuse possess the seemingly paradoxical property of conditioning rats to avoid from drinking a saccharin solution that had been predictively paired with their systemic administration (conditioned saccharin avoidance, CSA). CSA is dependent upon an intact dopamine (DA) transmission but the locus, central or peripheral, and eventually the brain area from which this effect originates and its relationship with the rewarding properties of the drug is debated. In order to clarify this issue we tested the ability of amphetamine and morphine to induce CSA after infusion at the same dose-range and in the same areas from which these drugs induce conditioned place preference (CPP). Drugs were infused intracerebrally immediately after saccharin drinking in two acquisition trials and CSA was tested on a two bottle saccharin/water choice. Amphetamine (10 and 20 µg/0.5 µl) induced CSA after infusion in the NAc shell but was ineffective in the NAc core. Morphine (0.5 and 1 µg/0.5 µl) induced CSA from the VTA at both doses tested. Amphetamine (20 µg/0.5 µl) and morphine (1 µg/0.5 µl) failed to induce CSA after infusion 1.2mm dorsal the NAc shell and the VTA respectively. Finally, morphine (1 µg/0.5 µl), infused in the VTA, elicited a selective increase in dialysate DA in the NAc shell. These results indicate that drugs of abuse induce CSA from the same intracerebral sites and at the same doses at which they induce CPP. These observations are consistent with the existence of a strong relationship between CSA and drug reward related to their ability to stimulate DA transmission in the NAc shell.

Scanning electron microscopy study of articular cartilage in the evolution of hip arthritis.

The authors report the results of scanning electron microscopy examination of samples of articular surface taken from 15 arthritic femoral heads removed during hip replacement. The specimens were collected from areas of the femoral head where different degrees of degenerative changes were identified, and processed with the normal techniques for scanning electron microscopy. A definition was made of the mechanisms leading to articular cartilage wear, the most obvious sign of cartilage degeneration. The earlier stages were characterized by the appearance of clefts in the surface layer, which merged and formed scales that flaked off, giving rise to superficial abrasions. The evolution of the degenerative process led to a deepening of the clefts, reaching the intermediate and deep layers and creating further scales of cartilage tissue, oblique or perpendicular to the surface. The elimination of these formations causes more or less marked wear that can extend down to the subchondral bone (ulcers and ground surfaces). As well as information on the condition of the articular surfaces, scanning electron microscopy may also provide details on the morphology and structure of the chondrocytes and the fibrillar network in the sagittal sections, showing the regressive phenomena associated with arthritis.

Human articular cartilage in osteoarthrosis. I. The matrix. Transmission electron microscopic study.

The present research has been carried out with the aim of contributing to the understanding of morphological changes in human articular cartilage during osteoarthrosis and to evaluate the usefulness of TEM in this application. Only the matrix was examined in this first phase of study. Fragments from the femoral head of 20 patients subjected total hip arthroplasis, were studied by TEM after treatment with current procedures. The images obtained were considered observing the division of cartilage into superficial, intermediate and deep layers. Patients were divided according to the gravity of their clinical conditions. The least severe forms of pathology seem to involve only the superficial layer, which quickly loses the lamina splendens and may be affected by rarefactions of the matrix, which becomes fissured, while the deep layers are only slightly involved. During the later stages, the pathology progresses with irregularity of disposition and size of the collagen fibres and an increase in the number and size of fissures. The intermediate layer shows architectural disorder in the collagen fibres, even reaching the deep layer. The interfibrillar distance appears greater. As pathology progresses, the superficial layer tends to disappear, while the successive layers undergo progressive alteration in disposition and size of the collagen fibres. Globular aggregations of various dimensions and electron density similar to collagen are present in the deep layer.

Morphological aspects of the synovial membrane and femoral epiphyseal cartilage in experimentally induced chronic anemia.

The authors describe the microscopic and ultrastructural changes in the synovial membrane and femoral growth cartilage in experimentally induced chronic anemia. The reiterated anoxic stimulus is responsible for premature morphologic changes which become progressively worse and then appear to stabilize after 30 days. The series of events at the completion of the experiment are characterized by the following: 1) villous hyperplasia-hypertrophy with an increase of the secretory vesicles of type B synoviocytes in the intima and lymphoplasmacellular infiltrates in the sub-intima of the synovial membrane with fragmentation of the bony trabeculae, 2) areas of premature closure of the growth cartilage, 3) irregularity of the profile, thickness, and structure of the articular cartilage. The authors propose a biologic correlation between the above osteoarticular changes and the typical features of certain disorders of this anatomical region (hemopathies, Legg-Calvé-Perthes disease).

Peripheral chondrosarcoma: ultrastructural investigation by transmission and scanning electron microscopy.

Ultrastructural analysis by transmission and scanning electron microscopy was performed on two grade 1 peripheral chondrosarcomas which had arisen from a preexisting osteochondroma. This analysis allowed us to determine the morphologic changes in both the cell and the matrix and suggested a low grade of malignancy. We emphasize that ultrastructural analysis with scanning and electron microscopy is only valid when conducted on representative areas of the tumor.

Morphological aspects of the synovial membrane and the femoral epiphyseal nucleus in anemia induced experimentally (note 1).

The authors describe the macroscopic and ultra-structural changes in the synovial membrane and the growth nucleus consequent to anemia induced experimentally. In the anatomical region studied an early and a late response to the transitory anoxia is observed. The former is represented by the accentuation of the macrophagic activity of the A synoviocytes and by pictures of trabecular fragmentation. The latter is represented by hyperplasia of the synovial membrane, a reduction in the thickness of the joint cartilage, and by early and patchy calcification of the epiphyseal disc.

[The role of osteotomy in the therapy of the arthritic genu varum]. / Il ruolo della osteotomia nella terapia del ginocchio varo artrosico.

The good results achieved with osteotomy in the treatment of arthritic varus knee lead the authors to pinpoint some frequently controversial aspects that are important for the attainment of an excellent outcome. The study consisted of 46 patients, each subjected to valgus osteotomy. The site of the tibial osteotomy should be above the insertion point of the patellar tendon in order to better guarantee stability and healing. For mechanical reasons, high metaphyseal peroneal osteotomy is preferred over other methods such as diaphyseal osteotomy, excision of the peroneal head, and proximal tibioperoneal syndesmotomy. Both osteotomies can be done through a single anterolateral incision, without risking injury to the lateral popliteal sciatic nerve. The preferred method of osteotomy is to cut a noncuneiform linear rima with the osteotome and perform the angular correction at the joint of the metaphyseal spongy bone. The osteotomy is then stabilized with staples and a cast for a period of 40 days. Overcorrection past the physiological valgus deformity is necessary in order to move the weight-bearing axis onto the lateral hemirima; the degree of surgical correction should be calculated on the basis of orthostatic radiographs. Good clinical results are always accompanied by the following radiographic developments: opening of the medial articular hemirima, improvement of the subchondral bone sclerosis, and reappearance of the outlines of both the spongy bone and the subchondral bone lamina; all these are signs of good bone adjustment made possible by the reinstatement of mechanical equilibrium in the knee.