Jean-Pierre Faure

S antigen-induced experimental autoimmune uveo-retinitis in rats

Experimental autoimmune uveoretinitis was induced in rats after one injection of purified retinal S antigen mixed with adjuvants. Lewis and PVG/c rat strains were highly sensitive. S antigens isolated from bovine, human, swine and guinea pig retinas had a high pathogenicity in Lewis rats, whereas allogenic S antigen did not induce the disease. Mycobacterial adjuvant was effect in both disease and antibody production but H. pertussis adjuvant strongly increased the severity of the ocular reaction, giving a hyperacute Arthus-type inflammation, even with low doses of antigen. No disease was found after immunization without bacteria (incomplete Freunds adjuvant or alum). With any bacterial adjuvant, the histological pattern was in agreement with the hypothesis of early reagin-mediated phenomena acting on the blood-retinal barrier, as suggested by previous experiments.

A Simple and Rapid Method for Isolation of Retinal S Antigen

A procedure is described for the rapid isolation of S antigen from retinal tissue, by salt precipitation, gel filtration and final purification by adsorption chromatography on hydroxyapatite-agarose. The method yielded a highly purified material and allowed an excellent preservation of the antigenicity, as shown by high pathogenic activity in induction of experimental autoimmune uveoretinitis.

PANCREATIC METASTASIS OF RENAL CELL CARCINOMA: PRESENTATION, TREATMENT AND SURVIVAL

PURPOSE The pancreas is an uncommon site of metastasis from renal cell carcinoma, comprising 2% of pancreatic tumors removed in sizable series of operations. To our knowledge the role of operative resection in the setting of metastatic malignancy to the periampullary region has not yet been defined. We reviewed the records of 6 women and 2 men who underwent pancreatic resection due to malignancy and analyzed various prognostic factors. MATERIALS AND METHODS Between 1985 and 1995, 269 patients underwent pancreatic resection for malignancy at our hospitals, including 150 (56%) for pancreatic duct cancer, 65 (24%) for carcinoma of the ampulla, 27 (10%) for distal bile duct cancer, 19 (7%) for duodenal carcinoma and 8 (3%) for renal cell carcinoma metastasis. We reviewed the records of these latter 8 cases, and analyzed demographics, primary tumor type, disease-free interval, resection type, concomitant other organ resection, histological examination of the specimen, morbidity, adjuvant therapy and survival. RESULTS Pancreatic metastasis of renal cell carcinoma was managed by duodenopancreatectomy in 5 patients and total pancreatectomy in 3. There were no perioperative deaths. Mean tumor size in cases of a solitary pancreatic metastasis was 4 cm. (range 1.5 to 8). In the 3 patients treated with total pancreatectomy there were 2, 5 and 3 pancreatic metastases, respectively. Pathological examination revealed negative lymph nodes in all cases. Mean survival was 48 months. At study end 6 patients were alive at 24, 26, 30, 46, 84 and 88 months, while 2 died at 13 and 70 months, respectively. CONCLUSIONS We advocate aggressive surgical resection when possible. Surgical removal of metastatic lesions prolongs survival but radical lymph node dissection is not mandatory. We also recommend careful long-term followup of patients with a history of renal cell carcinoma.

ANTI-RETINAL AUTOIMMUNITY AND CIRCULATING IMMUNE COMPLEXES IN PATIENTS WITH RETINAL VASCULITIS

Sera from 44 patients with isolated retinal vasculitis (RV), 38 patients with retinal vasculitis accompanying systemic inflammatory diseases (RV + SID), and 33 patients with a similar range of systemic inflammatory diseases without eye involvement (SID alone) were assayed for circulating immune complexes (CIC) and for anti-retinal autoantibodies. CIC were present in 41% of patients with isolated RV and 55% of patients with RV + SID, whilst anti-retinal antibodies were present in about 70% of all patients with RV. 42% of those with SID alone had CIC and 30% of those with SID alone had retinal autoantibodies. Titres of anti-retinal antibodies were higher in patients with RV than in those with SID alone. In isolated RV there was an inverse relation between pronounced retinal autoimmunity and the occurrence of CIC--i.e., the more severe autoimmune retinal disease occurred in CIC-negative patients. Most patients with RV + SID tended to have mild or moderate retinal disease accompanied by both retinal autoantibodies and CIC, but severe retinal disease occurred in CIC-positive patients who did not have circulating anti-retinal antibodies. Patients with SID alone had high titres of retinal antibodies only when they were CIC-positive. It is suggested that the formation of CIC, possibly of an idiotype/anti-idiotype nature, may be a compensatory mechanism accompanying anti-retinal autoimmunity and that an imbalance between autoimmunity and immune complex formation may be an important predisposing factor in the development of retinal inflammatory disease.

Production and specificity of monoclonal antibodies to retinal S antigen

Hybridomas producing monoclonal antibodies to the retinal S antigen were obtained by fusion of spleen cells from a BALB/c mouse immunized with purified bovine S antigen and NS-1 myeloma cells. Six cloned hybridomas were selected and expanded as large scale cultures and as ascites in mice. The specificity of the antibodies produced by these hybridomas was assessed by ELISA and immunofluorescence. All were specific for S antigen, except one which showed slight reactivity with other proteins. One antibody was specific for bovine S antigen, whereas the others showed cross reactivity with purified S antigens from various mammals. Immunofluorescence allowed to demonstrate the presence of common epitopes of S antigen in the retinal photoreceptor cells of species representative of every class of Vertebrates.

Protective roles of polyethylene glycol and trimetazidine against cold ischemia and reperfusion injuries of pig kidney graft.

Ischemia‐reperfusion injury (IRI) represents an allo‐independent risk factor which favors chronic allograft nephropathy (CAN). Here we analyzed the influence of preservation solutions on the function of autotransplanted pig kidneys over 1–16 weeks after surgery. Kidneys were cold‐flushed and cold‐stored for 24 or 48 h either in University of Wisconsin (UW), modified‐UW Hôpital Edouard Herriot, polyethylene glycol 20 kDa (PEG)‐supplemented preservation solutions with low K+ (ECPEG) or high K+ (ICPEG) content. Animals autotransplanted with kidneys cold‐stored for 24 h in ECPEG exhibited the greatest levels of creatinine clearance (Ccr: 161 ± 12 mL/min, n = 10) and the lowest levels of proteinuria (0.5 ± 0.03 mg/mL) 16 weeks after surgery as compared with pigs autotransplanted with kidneys cold‐stored in the other solutions tested (Ccr ranging from 80 and 140 mL/min). Similar differences, but with lower Ccr levels, were achieved after a prolonged period of cold‐storage(48 h). ECPEG better preserved the kidneys from monocytes/macrophages and CD4+ T cells infiltrations, VCAM‐1 and MHC class II overexpressions and occurrence of renal interstitial fibrosis (2%) as compared with the other preservation solutions (5%–20%). Adding the anti‐ischemic drug trimetazidine (TMZ) to the preservation solutions, particularly ECPEG, further improved the quality of the week‐16 post‐transplanted kidneys (Ccr: 182 ± 12 mL/min, n = 10). These findings demonstrated that adding PEG to extracellular‐like (with low K+ content) preservation solutions in combination with TMZ significantly improved the long‐term outcome of kidney grafts in this model of autotransplanted pig kidney.

Study of the ultrastructure of the rabbit corneal endothelium by the freeze-fracture technique: apical and lateral junctions.

Abstract Freeze-fracture replicas of the rabbit cornea were used to study the spatial structure and the general characteristics of the endothelial cell layer. Between adjacent endothelial cells discontinuous, non-complete occluding junctions were observed which correspond to the junctional elements of the “terminal bar” at the apex of endothelial cells, under the apical folds. They are constituted by rows of interconnected particles on the fracture P-face, and by corresponding furrows on the fracture E-face. On the lateral sides on the cells, there are gap junctions which appear as linear arrays of particles on the P-face and as geometrically arranged complementary pits on the E-face. The apical occluding junctions, as well as the lateral gap junctions are discontinuous, and hence do not constitute a complete barrier for the diffusion of solutes from the anterior chamber into the intercellular spaces.

Polyethylene Glycol Reduces Early and Long-Term Cold Ischemia-Reperfusion and Renal Medulla Injury

Ischemia-reperfusion injury (IRI) after transplantation is a major cause of delayed graft function, which has a negative impact on early and late graft function and improve acute rejection. We have previously shown that polyethylene glycol (PEG) and particularly PEG 20M has a protective effect against cold ischemia and reperfusion injury in an isolated perfused pig and rat kidney model. We extended those observations to investigate the role of PEG using different doses (30g or 50g/l) added (ICPEG30 or ICPEG50) or not (IC) to a simplified preservation solution to reduce IRI after prolonged cold storage (48-h) of pig kidneys when compared with Euro-Collins and University of Wisconsin solutions. The study of renal function and medulla injury was performed with biochemical methods and proton NMR spectroscopy. Histological and inflammatory cell studies were performed after reperfusion (30–40 min) and on days 7 and 14 and weeks 4, 8, and 12. Peripheral-type benzodiazepine receptor (PBR), a mitochondrial protein involved in cholesterol homeostasis, was also studied. The results demonstrated that ICPEG30 improved renal function and reduced medulla injury. ICPEG30 also improved tubular function and strongly protect mitochondrial integrity. Post-IRI inflammation was strongly reduced in this group, particularly lymphocytes TCD4+, PBR expression was influenced by IRI in the early period and during the development of chronic dysfunction. This study clearly shows that PEG has a beneficial effect in renal preservation and suggests a role of PBR as a marker IRI and repair processes.

Formation of intercellular spaces and junctions in regenerating rabbit corneal endothelium

Abstract Rabbit corneal endothelium was destroyed over a diameter of 10 mm using liquid nitrogen applied for 15 sec to the anterior surface. The corneas were afterwards removed at different periods, from 1 day to 2 months and studied by light microscopy after silver impregnation, by transmission electron microscopy, and by scanning electron microscopy in order to study the formation of new intercellular spaces and junctions in the regenerating endothelium. The intercellular spaces and junctions are all reconstituted at the end of the fifth day, when the whole of Descemets membrane is entirely covered by cells. This period also corresponds to the recovery of the endothelial function. The dynamics of the formation of intercellular spaces are described, and the rapid appearance of two types of junctions as soon as contact between cells is completed. Junctions of the first type, always at the apex of the cells, are single or multiple with adjacent intra-cytoplasmic opacities and correspond to the junctional elements of the “terminal bar”. Junctions of the second type, on the lateral plasma membranes of the cells, are not constantly observed; they are straight, or curved. or circular; their length is variable, and they possess a periodicity in their structure, and correspond to gap junctions.

Pineal-retinal molecular relationships: distribution of S-antigen in the pineal complex

The immunocytochemical localization of S-antigen, a specific protein first discovered in retinal photoreceptors, was studied in the pineal complex of vertebrates (eel, pike, frog, lizard, passerines, mouse, hamster) using monoclonal antibody immunofluorescence. S-antigen immunoreactivity was demonstrated concurrently in retinal photoreceptors and in most pineal phototransducers of all species, i.e. in pineal cells of the receptor series (cone-like, modified photoreceptor cells, pinealocytes) and in cone-like photoreceptors of the frog frontal organ and lizard parietal eye. The labelling was distributed either in all compartments of these cells, or restricted to outer segments. The functional significance of the S-antigen as well as some phylogenetic and ontogenic implication of this marker are discussed.