Laparoscopic vs open subtotal colectomy for benign and malignant disease

AIM: The present meta-analysis aims to compare short-term and long-term outcomes in patients undergoing laparoscopic or open subtotal colectomy for benign and malignant disease. METHODS: A literature search of Medline, Ovid, Embase and Cochrane databases was performed to identify studies published between 1992 and 2005, comparing laparoscopic (LSC) and open (OSC) subtotal colectomy. A random effect meta-analytical technique was used and sensitivity analysis performed on studies published since the beginning of 2000, higher quality papers, those reporting on more than 40 patients, and those studies reporting on adult cases or acute colitis. RESULTS: A total of eight studies satisfied the criteria for inclusion. These included outcomes on 336 patients, 143 (42.6%) of whom had undergone laparoscopic resection, with an overall conversion rate to open surgery of 5% (range 0-11.8%). Operative time was significantly longer in the laparoscopic group by 86.2 min (P < 0.001) and throughout subgroup analysis, although it was only in patients with acute colitis that this finding was without significant heterogeneity. Operative blood loss was less in the laparoscopic group by 57.5 millilitres in high quality and studies published since 2000, and 65.3 millilitres in those reporting on more than 40 patients. There was no significant difference in early or long-term complications between the groups. A statistically significant reduction in length of postoperative stay was observed in the laparoscopic groups by 2.9 days (P < 0.001). CONCLUSION: Laparoscopic subtotal colectomy was associated with longer operating times but a reduced length of stay compared to open surgery. Although short-term outcomes were equivalent in both groups, the suggested benefits in terms of reduced long-term obstructive complications were not supported by this meta-analysis.     

Evidence that monoclonal antibodies against the 55kD subunit of the rat IL-2 receptor do not inhibit the development of suppressor cells generated in mixed lymphocyte culture

Although the ability of Ts to prevent allograft rejection has been well established, their intrinsic characteristics and dependence upon lymphokines remain poorly defined. The cells from unmodified LEWxBN bulk 5-day rat MLR inhibit both proliferation in test MLR and generation of CTL, as well as prolonging the survival of donor-specific test cardiac allografts following adoptive transfer. We have examined the effects of a panel of mAb directed against functionally distinct epitopes on the p55 subunit of rat IL-2R on the generation and in vitro/in vivo activity of MLR-generated Ts. ART-18 (which blocks IL-2-dependent T cell growth) was the only mAb from the panel that profoundly suppressed alloreactive T cell proliferation in primary MLR (47.5%). However, the generation of Ts was never affected by any mAb (% suppression in test MLR = 40-60%). Neither ART-18 nor ART-65 (which does not affect T cell proliferation) interfered with the efficacy of Ts to inhibit CTL generation in fresh bulk MLR. Adoptive transfer of cells (3-10 x 10(6] from ART-18 or ART-65-modulated MLR into naive LEW rats prolonged (LEW x BN)F1 test cardiac allograft survival to 11-13 days (P less than 0.05 as compared with acutely rejecting hosts). All in vitro and in vivo effects exerted by MLR-generated cells were antigen-specific. In unmodified MLR, Ts were IL-2R+ (ca. 50% of total blasts), as shown by cell separation using magnetic beads. In contrast, in MLR with ART-18 added, Ts were primarily IL-2R- (ca. 10% of blasts). Thus, antirat p55 subunit IL-2R mAb do not inhibit MLR-generated Ts functionally operative in vitro and in vivo. IL-2R- Ts precursors requiring lymphokine(s) other than IL-2 may differentiate into IL-2-dependent Ts effectors. Such divergent IL-2 requirements for Ts growth in vitro may explain the Ts-sparing effects in allograft recipients treated with anti-IL-2R mAb.     

Adhesion molecules and transplantation.

OBJECTIVE: Accessory adhesion molecules are thought to influence the first interaction between host leukocytes and graft vascular endothelial cells. Their role in transplantation is reviewed. SUMMARY: Adhesion molecules have been divided into three major families: the selectins, the integrins, and the immunoglobulin superfamily. Selectins are small proteins that mediate the first contact between stimulated endothelial cells and leukocytes. Integrins interact with cytoskeletal components of cells, presumably coordinating extracellular stimuli with cytoskeleton dependent actions, such as motility, shape change, and phagocytic responses. Members of the immunoglobulin superfamily are structurally homologous, although they do not necessarily share similar functions. They are involved in T-cell proliferation and intracellular events. METHODS: Various groups of investigators have studied the influence and expression of adhesion molecules following transplantation. The authors of this article have reviewed and summarized the available literature. RESULTS: Many different adhesion molecules are up-regulated during the rejection event. Treatment of transplant recipients with monoclonal antibodies against accessory molecules, such as leukocyte function associated antigen 1 (LFA-1) and intercellular adhesion molecule 1 (ICAM-1), has resulted in either a prolongation of transplant survival or the induction of tolerance in some models. Other interventions are under study. CONCLUSION: By mediating the initial leukocyte/endothelial cell interactions, adhesion molecules may play an important role in graft rejection, mediation of infiltration into the graft, and dissemination of the antigenic message to the lymphoid tissues of the host. Future studies will have to deal not only with conceptualizing their function and mechanisms of action, but also with manipulating their interrelationships to the benefit of the graft recipient.     

Role of listeriolysin O in cell-to-cell spread of Listeria monocytogenes

Listeria monocytogenes is a facultative intracellular bacterial pathogen that escapes from a host vacuolar compartment and grows rapidly in the cytosol. Listeriolysin O (LLO) is a secreted pore-forming protein essential for the escape of L. monocytogenes from the vacuole formed upon initial internalization. However, its role in intracellular growth and cell-to-cell spread events has not been testable by a genetic approach. In this study, purified six-His-tagged LLO (HisLLO) was noncovalently coupled to the surface of nickel-treated LLO-negative mutants. Bound LLO mediated vacuolar escape in approximately 2% of the mutants. After 5.5 h of growth, cytosolic bacteria were indistinguishable from wild-type bacteria with regard to formation of pseudopod-like extensions, here termed listeriopods, and spread to adjacent cells. However, bacteria in adjacent cells failed to multiply and were found in double-membrane vacuoles. Addition of bound LLO to mutants lacking LLO and two distinct phospholipases C (PLCs) also resulted in spread to adjacent cells, but these triple mutants became trapped in multiple-membrane vacuoles that are reminiscent of autophagocytic vacuoles. These studies show that neither LLO nor the PLCs are necessary for listeriopod formation and uptake of bacteria into neighboring cells but that LLO is required for the escape of L. monocytogenes from the double-membrane vacuole that forms upon cell-to-cell spread.     

The systemic distribution of soluble antigen injected into the footpad of the laboratory rat

Injection into the hind footpad of the rat combines intradermal and subcutaneous routes. Material injected into the dermis of the sole is rapidly distributed by the lymphatics to several lymph node groups and enters the bloodstream principally with the thoracic duct lymph. The diffuse character of the lymphatic drainage of this site is emphasized. Material in the subcutaneous tissues gradually enters the systemic circulation and is filtered through various organs. Antigen injected into the footpad can elicit both effective delayed hypersensitivity and humoral host responses.