Lewis lung carcinoma cells enhance the synthesis of C3 and are opsonized by C3 secreted from murine macrophages

We investigated the effect of Lewis Lung carcinoma cells on the production of C3 by murine macrophages and examined the capacity of secreted C3 to opsonize Lewis Lung carcinoma cells. C3 released in culture from macrophages obtained from tumor-bearing C57Bl/6 mice as well as from normal macrophages exposed to Lewis Lung carcinoma cells in vitro was measured by hemolytic assays and by Western blot. We found that contact with tumor cells in vivo as well as in vitro enhanced the amount of C3 secreted by murine macrophages by a factor of 2-3. The inflammatory agent carrageenan caused only a small increase in the amount of secreted C3. On Western blots of concentrated macrophage supernatants, there was partial cleavage of secreted C3 which was, however, not more pronounced in the case of C3 from tumor-stimulated macrophages than from normal macrophages. Supernatants from normal as well as tumor-stimulated macrophages were capable of opsonizing Lewis Lung carcinoma cells as shown by their capacity to bind human erythrocyte in an immune adherence reaction. Pretreatment of the tumor cells with a protease inhibitor, PMSF, inhibited the capacity of the tumor cells to bind C3, suggesting that a tumor cell-associated protease might be involved in the binding of C3 to the tumor cell surface.     

Scanning electron microscopy of jejunal biopsies in patients with untreated and treated coeliac disease

Biopsy specimens of jejunal mucosa from children with coeliac disease (CD) were examined by scanning electron microscopy (SEM) and light microscopy (LM) before and after gluten-free diet. The results demonstrate that SEM is more sensitive than LM in documenting early morphological restoration of jejunal mucosa in patients treated with gluten-free diet.     

Recovery Factors Affecting Utilization of Small Pediatric Donor Kidneys

Kidneys from small pediatric donors are underutilized. Using data from the Scientific Registry of Transplant Recipients for donors <21 kg in which at least one organ was recovered from 1997 to 2007 (n = 3341), donor and recovery factors were evaluated by multivariate analysis for associations with (a) kidney nonrecovery and (b) transplantation of recovered kidneys. Results: The proportion of kidney recoveries were 55% during liver procurements and 40% during intestine procurements amongst donors <10 kg (p < 0.01) compared to 93% and 88%, respectively, for donors weighing 10–20 kg (p = 0.003). Intestine procurement was independently associated with an 81% greater likelihood of kidney nonrecovery (p < 0.0001) and a 48% lower likelihood of transplantation (p = 0.0004). A multivariate Cox model indicated that single kidney recipients had a 63% higher risk of graft failure compared with en bloc kidney recipients (p < 0.0001); however, concurrent intestine recovery was not a significant risk factor for graft loss. Intestine recovery from donors <21 kg of age is strongly associated with higher kidney nonrecovery and lower transplantation rates. Graft survival is worse with single kidney transplantation, but is not significantly affected by intestine recovery. Small pediatric donors procurement teams should strive to increase kidney recoveries overall and en bloc recoveries in particular.     

Characterization of the mucins produced by normal human colonocytes in primary culture

Mature goblet cells filled with mucin ready for secretion represent about one third of the cells in primary cultures of human colonocytes. In the present study characterization of the mucins produced by cultured human colonocytes was made by histochemical methods by lectin and monoclonal antibody binding. Two monoclonal antibodies and three lectinsDolichos biflorus (DBA),Helix pomatia (HPA) andArachis hypogea (PNA) recognizing epitopes or sugar haptens characteristic of different stages of mucin glycoprotein maturation, were employed. The reacivity to these probes was tested both on cultured colonocytes and on tissue sections of the normal colon mucosa. The results show that the mucins produced in culture are glycosylated to the mature form, as they show the same reactivity to lectins and antibodies of the mucins expressed in tissue sections of the normal colon mucosa. In addition, it is demonstrated that cultured human colonocytes do not express mucins reactive to PNA, which are characteristic of tumors. Since the cultured colonocytes maintain the expression of differentiated functions for at least three days, they may offer a useful model to study metabolism, function and regulation of colon mucins in health and disease.

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Résumé Des cellules caliciformes matures remplies de mucine prêtes à la sécrétion constituent environ 1/3 de toutes les cellules dans des cultures primaires de colonocytes humains. Au cours de l'étude présente, les mucines produites par des cultures de colonocytes humains ont été typisées par des méthodes histochimiques, par liaison à la lectin et à des anti-corps monoclonaux. Deux anti-corps monoclonaux et trois types de lectin Dolichos biflorus (DBA), Helix pomatio (HPA) et Arachis hypogea (PNA) susceptibles de reconnaïtre les épitopes ou les haptènes d'hydrate de carbone caractéristiques de différentes phases de la maturation des glycoprotéines des mucines ont été emplyés. Les réactivités à ces substances ont été testéees à la fois sur des cultures de colonocytes et sur des segments de tissu muqueux coliques normaux. Les résultats montrent que les mucines produites en culture sont glycosylées dans les formes matures car elles présentent la même réactivité aux lectins et aux anti-corps des mucines tels que mesurés dans des segments de tissue de muqueuse colique normale. De plus, on a démontré que les colonocytes humains cultivés ne produisent pas de mucine réactive au PNA qui sont caractéristiques des tumeurs. Etant donné que les colonocytes humains cultivés conservent l'expression d'une différenciation des fonctions pour au moins trois jours, ils peuvent constituer un modèle utile pour étudier le métabolisme de la fonction et de la régulation des mucines coliques chez le sujet sain et pathologique.

     

Searching for Preclinical Models of Acute Decompensated Heart Failure: a Concise Narrative Overview and a Novel Swine Model

Cardiovascular Drugs and Therapy - Available animal models of acute heart failure (AHF) and their limitations are discussed herein. A novel and preclinically relevant porcine model of decompensated...     

PROviding Better ACcess To ORgans: A comprehensive overview of organ‐access initiatives from the ASTS PROACTOR Task Force

The American Society of Transplant Surgeons (ASTS) PROviding better Access To Organs (PROACTOR) Task Force was created to inform ongoing ASTS organ access efforts. Task force members were charged with comprehensively cataloguing current organ access activities and organizing them according to stakeholder type. This white paper summarizes the task force findings and makes recommendations for future ASTS organ access initiatives.