Purkinje cell abnormalities and synaptogenesis in genetically jaundiced rats (Gunn rats)

The course of cytological abnormalities and synaptogenesis of Purkinje cells were investigated in the culmen of cerebella from homozygous Gunn rats with hereditary hyperbilirubinemia from postnatal day 7 to adulthood (5-10 months old). The affected Purkinje cells were abundant at day 7. A large number of Purkinje cells reached the fully advanced stage of degeneration during the ensuring 16 days and disappeared between days 12 and 30. The Purkinje cells remaining at day 30 were less affected and recovered by the adult stage. Various abnormalities in Purkinje cell synaptogenesis with the parallel fibers, climbing fibers, and basket and stellate cell axons were observed. Primitive junctions between parallel fibers and Purkinje dendritic shafts were often found in adulthood. The parallel fiber boutons lacking postsynaptic partners and facing astrocytic processes were often noted from day 18 to adulthood. The persistence of such presynaptic elements suggests some mechanisms for stabilizing the synaptic elements once they have been formed. Many of the parallel fiber synaptic boutons with or without their postsynaptic partners were enlarged and were assumed to be transsynaptically affected by Purkinje cell damage. A number of climbing fiber synapses with perisomatic process of Purkinje cells, which are transient in normal synaptogenesis, were present at day 30 and a few of them were still found even in adulthood. Basket and stellate cell synapses were often found in abundance on the remaining Purkinje cells in adulthood, though they were not frequently encountered during the development period.     

Experimental arthritis induced by continuous infusion of IL-8 into rabbit knee joints.

To determine the roles of IL-8 in inflammatory synovitis, examination was made of the results of continuously injecting human recombinant IL-8 into the knee joints of New Zealand while rabbits. Recombinant human IL-8 was infused continuously into the joint cavity at 75 ng/h for 14 days by a polypropylene catheter connected to a mini-osmotic pump implanted in each rabbit. Infiltration of inflammatory cells into joint cavity and histopathological changes in synovial tissue were examined at 7 and 14 days following the start of infusion. The continuous infusion of IL-8 for 14 days led to severe arthritis characterized by apparent erythema and joint pain, the accumulation of leucocytes, infiltration of mononuclear cells in synovial tissue, and marked hypervascularization in the synovial lining layer. IL-8 may be a factor which can contribute to the inflammatory process of chronic arthritis by mediating leucocyte recruitment and hypervascularization in inflamed joints.     

BRONCHIAL CARCINOID ACCOMPANIED BY THYROID ADENOMAS AND ADRENAL ADENOMAS

A large tumor massively occupying the left pleural cavity had the Andings of both typical carcinoid and oncocytoma which were thought to be of bronchogenic origin. The ultrastructural observation of the tumor revealed a mixture of rod-shaped granules in addition to usual round neurosecretory ones. In the nuclei of dark cells of the oncocytoma, a latticed or hatched structure was detected. Besides two adenomas and hyperplastic foci of large acidophilic cells in the thyroid, a black adenoma and cortical adenoma in the adrenal gland, were detected. Moreover, there was an ectopic adrenal gland in the retroperitoneum. Briefly it was suggested that the bronchial carcinoid presented may be related to multiple endocrine adenomatosis.     

Comparative study of effects of cyclosporins A and G on collagen arthritis in mice

The effects of the immunosuppressive agents cyclosporin G (CsG) and cyclosporin A (CsA) on collagen arthritis were compared in mice. When administered subcutaneously daily on days 0–13 after immunization with type II collagen, CsG and CsA were both capable of suppressing the development of collagen arthritis in mice as well as the immunological response to native type II collagen in a dose-dependent manner. Histopathologically, no marked inflammatory lesions were observed in diarthroidal joints from mice treated with 100 mg/kg per day of CsA or 800 mg/kg per day of CsG. However, an analysis of dose response showed CsG to be 8 times less potent than CsA in inhibiting the development of arthritis.     

Expression of the histamine H1 receptor gene in relation to atherosclerosis.

Histamine in serum and arterial tissue contributes to the pathogenesis of atherosclerosis and the formation of coronary artery vasospasm. As the effect of histamine at a given site will be mediated by its specific receptors, we investigated by in situ hybridization and Northern blot analysis the expression and localization of human histamine H1 receptor mRNA in the arterial wall and in cultured human aortic intimal smooth muscle cells (SMC) and immortalized SMC (ISS10) and endothelial cells (SE1). In situ hybridization showed that SMC and endothelial cells expressed H1 receptor mRNA in vivo and that the expression was increased in SMC in the thickened intima of atherosclerotic foci in both the aorta and coronary artery. By Northern blot analysis, we also detected histamine H1 receptor mRNA in cultured SMC, ISS10, and SE1 and found that platelet-derived growth factor stimulated SMC to increase their expression of the mRNA in vitro. These results suggest that up-regulation of histamine H1 receptor expression by platelet-derived growth factor plays an important role in the initiation and progression of cardiovascular diseases.     

Neuroectodermal tumor of bone. Evidence for neural differentiation in a cultured cell line

A new cell line was established from a "neuroectodermal tumor of bone" affecting the right scapula of an 18-year-old man. The original neoplasm had dense proliferation of small round cells with abundant glycogen content and numerous Homer-Wright rosettes. The culture showed proliferation of small spindle cells with uniform oval nuclei and slender cytoplasmic processes. When the culture reached maximum density, rosette-like structures similar to those in the original tumor were formed. Under the influence of N6,O2'-dibutyryl adenosine 3',5'-cyclic monophosphoric acid (dibutyryl cAMP), the cultured cells expressed these rosette-like structures even in the lower cell concentration. Electron microscopy revealed that the cultured cells treated with dibutyryl cAMP contained high-density granules, well-developed microtubules, and abundant 10-nm filaments. By immunocytochemistry, neuron-specific enolase (NSE), and N-myc oncogene product were detected in the cultured cells as well as the original tumor. These results indicated the neuroectodermal origin of some of the small round cell tumors of bone.     

The management of medial ligament tears in patients with combined anterior cruciate and medial ligament lesions

The management of patients with combined medial collateral (MCL) and anterior cruciate (ACL) rupture remains controversial. We studied 25 such patients who elected to have the ACL lesion treated conservatively; 14 underwent MCL repair with early mobilization and 11 were treated with immobilization for two weeks. The mean follow up was 5.9 years (2 to 11). There was no difference in the clinical assessment of ligamentous laxity, KT-1000 measurements or Tegner activity scores between the two groups but there were significantly higher Lysholm function scores in the operated group.

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Résumé Le traitement optimal des cas associant des lésions du ligament croisé antérieur (ACL) à des lésions médiales collatérales (MCL) est controversé. Nous avons réalisé une étude sur le suivi du traitement de telles lésions dans le but d’évaluer si le traitement opératoire des déchirures de MCL peut apporter une amélioration des résultats fonctionnels pour des patients choisissant de ne pas subir une reconstruction de ACL. Notre étude portait sur 14 patients ayant subi une reconstruction du MCL et 11 patients traités sans opération. Nous n’avons pas observé de différences significatives entre les deux groupes pour les tests de relachement manuel, ni pour les mesures KT-1000, ni pour les niveaux d’activité de Tegner. En revanche les patients du groupe opératoire ont obtenu un meilleur score fonctionnel de Lysholm.

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Accepted: 7 December 1999