¿Hay un modelo experimental animal adecuado para el estudio del hombro? / Is there an adequate experimental animal model for the study of the shoulder?

Objetivo: Describir el esqueleto de la articulación del hombro en diferentes especies para establecer un modelo experimental de la patología del hombro. Material y metodología: Obtuvimos hombros de diferentes especies: perro (beagle), cerdo (mini-pig), conejo de Nueva Zelanda, liebre, cordero y oveja adulta. Extrajimos las articulaciones escápulo-humerales de ambos lados. Efectuamos una radiografía en cuatro proyecciones (antero-posterior, axial y dos oblicuas) y un TAC con reconstrucción tridimensional. Posteriormente disecamos las piezas para analizar el espacio subacromial y la cavidad glenoidea. Resultados: Ninguna de las especies analizadas posee un acromion desarrollado ni coracoides para definir un espacio subacromial. El cerdo presenta una cápsula posterior más desarrollada que la anterior y un m. subescapular desarrollado y el m. bíceps presenta un tendón en su porción larga pequeño y extraarticular con una corredera bicipital profunda. La oveja presenta un labrum superior desarrollado, con un tendón de la porción larga del m. bíceps en una corredera poco profunda. Conclusión: No hemos encontrado un modelo experimental adecuado para estudiar la patología del espacio subacromial. La oveja y el cerdo pueden ser buenos modelos para estudiar la patología de la glenoides (AU)

Objective: To describe the skeleton of the shoulder joint in different species to establish an experimental model of shoulder pathology. Material and methods: Shoulders were obtained from different species: dog (beagle), pig (minipig), New Zealand rabbit, hare, lamb and adult sheep. The scapulohumeral joints from both sides were extracted. X-ray images were obtained in 4 projections (anteroposterior, axial and two oblique) and a CT scan with 3D reconstruction. We then dissected the pieces to analyze the subacromial space and glenoid cavity. Results: None of the species analyzed possesses a developed acromion or coracoid to define a subacromial space. The pig has a more developed posterior than anterior capsule and a developed subscapularis muscle and the biceps muscle has a tendon on its extraarticular small long portion with a deep bicipital groove. The sheep has a developed superior labrum, with a tendon of the long portion of the biceps muscle in a shallow groove. Conclusion: We did not find an adequate experimental model to study the pathology of the subacromial space. The sheep and the pig may be good model to study the pathology of the glenoid (AU)

Identification of tissue factor in two human pancreatic cancer cell lines.

We have studied the effects of two human pancreatic cancer and two human small cell lung cancer cell lines on clotting and platelet aggregation. Both pancreatic lines markedly shortened recalcification times and induced platelet aggregation. The lung cancer lines produced little shortening of recalcification times and no platelet aggregation. The clotting and aggregation activities of the pancreatic lines were further characterized. Recalcification times following the addition of cancer cell line material to plasmas deficient in factors VII and X were markedly prolonged, suggesting that the activity is due to tissue factor. Hirudin, an inhibitor of thrombin from the saliva of leeches, and rabbit polyclonal immunoglobulin G anti-bovine brain tissue factor inhibited both procoagulant and aggregation activities. Apyrase (an enzyme degrading ADP), diisopropylfluorophosphate (a serine protease inhibitor) and L-trans-epoxysuccinylleucylamido(4-guanidino)butane (a cysteine protease inhibitor) failed to inhibit these activities. Increasing concentrations of heparin inhibited platelet aggregation. Subcellular fractionation studies showed these activities to be localized to the plasma membrane. The association between mucin and the acceleration of clotting has been well described. The absence of mucin in electron micrographs of these pancreatic whole cells, membrane fractions, and shed microvesicles, as well as the failure of chaotropic agents (i.e., agents stripping material extrinsic to the cell membrane such as mucin) to abrogate this activity support these activities being intrinsic to the plasma membrane. These data strongly suggest that these activities are due to tissue factor which appears to be released as microvesicles in vitro. The release of tissue factor via microvesicles in vivo is one possible mechanism for the coagulopathy sometimes seen in patients with pancreatic carcinoma.

Hemolytic uremic syndrome in a patient with small cell lung cancer.

Hemolytic uremic syndrome is a rare entity in patients with carcinoma and presents with a triad of renal insufficiency, microangiopathic hemolytic anemia, and thrombocytopenia. We report this syndrome for the first time in a patient with small cell lung carcinoma. Spontaneous platelet aggregation of washed normal platelets was demonstrated using patient plasma. Circulating immune complex levels were not elevated. The entity completely resolved after treatment with plasma, vincristine, aspirin, and dipyridamole.

Acute nonlymphocytic leukemia after thiotepa instillation into the bladder: report of 2 cases and review of the literature.

We report 2 cases of acute nonlymphocytic leukemia after thiotepa instillation into the bladder for superficial bladder carcinoma and review 4 additional cases from the literature. Intravesical thiotepa is absorbed systemically in patients with bladder carcinoma and such treatment may be associated with the rare occurrence of acute nonlymphocytic leukemia and/or the myelodysplastic syndrome.