Effects of different perfusates on functional parameters of isolated perfused dog kidneys.

BACKGROUND: The isolated perfused canine kidney has been established as a valid model for conducting both renal physiology and transplantation research. This model is of particular importance for developing new strategies to improve graft function after renal transplantation. In the present study, a newly developed method using isolated haemoperfused porcine kidneys was adapted for use in canine kidneys. In contrast to haemoperfusion, synthetic perfusion media can be standardized and can prevent the initiation of blood-mediated reperfusion reactions. Thus, an additional aim was to determine whether blood could be replaced by synthetic cell-free perfusion solutions. METHODS: Canine kidneys (n = 30) were harvested from donors euthanized in veterinary practices for causes unrelated to the present study. The kidneys were isolated and perfused with autologous blood or cell-free synthetic electrolyte buffer (Tyrode solution). During perfusion, we monitored renal perfusate flow (RPF), glomerular filtration rate (GFR), electrolyte and glucose reabsorption, oxygen consumption and urine concentration. RESULTS: Changes in perfusion medium did not affect the RPF. In contrast, GFR, urine concentration and oxygen consumption were significantly higher, whereas fractional excretion of sodium and glucose were significantly lower in blood- than in Tyrode-perfused kidneys. CONCLUSIONS: This system offers a simple model for studying whole-organ functional alterations after acute renal ischaemia. Renal function indicators were below values reported during in vivo physiological conditions. These functions were better conserved when kidneys were perfused with autologous blood than with Tyrode.     

Meniscal abnormalities: prospective correlation of double-contrast arthrography and arthroscopy

In a prospective study conducted over a 12-month period, 30 patients underwent double-contrast arthrography of the knee followed by arthroscopic study. An 80% correlation rate was found between results. Arthrography had a higher rate of accuracy (93%) than arthroscopy (84%) and had a 7% false-positive and 0% false-negative rate. A commonly overlooked arthrographic sign--the triple-S or stuck sail sign--was 91% accurate in the prediction of meniscal tears. The complementary nature of the two examinations is discussed.     

Patellofemoral joint: kinematic MR imaging to assess tracking abnormalities

The patellofemoral joint was imaged with magnetic resonance (MR) in the axial plane while the knee was positioned from 0 degrees to 32 degrees of flexion (nine positions). These multiple sequential images obtained within the early phases of flexion of the knee were viewed in a "cine-loop" format, producing a kinematic study that clearly demonstrated the relationship of the patella to the trochlear groove. Four healthy subjects and one patient with known bilateral subluxing patellae were studied. The preliminary results suggest that kinematic MR imaging of the patellofemoral joint is potentially useful for the evaluation of patellar tracking abnormalities.     

Clinical use of a standard kit-preparation of radiolabeled monoclonal antibody 96.5 in the diagnostic imaging of metastatic melanoma

We studied the efficiency of a standard-kit preparation using 1 mg 111In-labeled 96.5 monoclonal antibody in combination with 19 mg of unlabeled antibody in the diagnostic imaging of 27 patients with documented metastatic melanoma. Twenty-three of 26 patients (88%) demonstrated immunoscintigraphic localization of tumor. Of 104 metastatic sites previously documented by conventional studies, 62 (60%) were identified by immunoscintigraphy. A total of 77 sites demonstrated localization of radiolabeled antibody. Fifty-four (70%) corresponded to known sites of disease; eight sites (10%) were "discovered" by immunoscintigraphy and subsequently confirmed by conventional studies; 15 imaged sites (20%) could not be confirmed by conventional studies. Size and location of metastasis appear to be important features that influence imaging efficiency. Tumor size (greater than or equal to 2 cm v less than 2 cm) appears to be the statistical dominant determinant. The feasibility and potential clinical use of radioimmune imaging of tumors is discussed.     

The role of inflammation in the development of epiretinal membranes

Single or multiple (3) injections of "Shigella" endotoxin were administered into the rabbit vitreous body to investigate the development of epiretinal membranes following intraocular inflammation. The evaluation included clinical assessment of the resulting traction retinal detachments, together with histological, autoradiographic, immunohistochemical and ultrastructural studies. Traction retinal detachments were found beneath fibroglial epiretinal membranes (being more extensive in eyes which had received 3 endotoxin injections) in the vicinity of the medullary rays, while purely glial membranes occurred over attached peripheral retina. The primary change at the vitreoretinal interface was an elevation of the inner limiting lamina of the retina followed by the extension of glial cells onto the retinal surface. It is postulated that glial cells breach the inner limiting lamina as a sequel to inflammation involving the vitreoretinal interface and form a scaffold upon which fibroblast-like cells migrate.