Bone-marrow-derived side population cells for myocardial regeneration.

Bone-marrow-derived stem cells have displayed the potential for myocardial regeneration in animal models as well as in clinical trials. Unfractionated bone marrow mononuclear cell (MNC) population is a heterogeneous group of cells known to include a number of stem cell populations. Cells in the side population (SP) fraction have a high capacity for differentiation into multiple lineages. In the current study, we investigated the role of murine and human bone-marrow-derived side population cells in myocardial regeneration. In these studies, we show that mouse bone-marrow-derived SP cells expressed the contractile protein, alpha-actinin, following culture with neonatal cardiomyocytes and after delivery into the myocardium following injury. Moreover, the number of green-fluorescent-protein-positive cells, of bone marrow side population origin, increased progressively within the injured myocardium over 90 days. Transcriptome analysis of these bone marrow cells reveals a pattern of expression consistent with immature cardiomyocytes. Additionally, the differentiation capacity of human granulocyte colony-stimulating factor stimulated peripheral blood stem cells were assessed following injection into injured rat myocardium. Bone marrow mononuclear cell and side population cells were both readily identified within the rat myocardium 1 month following injection. These human cells expressed human-specific cardiac troponin I as determined by immunohistochemistry as well as numerous cardiac transcripts as determined by polymerase chain reaction. Both human bone marrow mononuclear cells and human side population cells augmented cardiac systolic function following a modest drop in function as a result of cryoinjury. The augmentation of cardiac function following injection of side population cells occurred earlier than with bone marrow mononuclear cells despite the fact that the number of side population cells used was one tenth that of bone marrow mononuclear cells (9 x 10(5) cells per heart in the MNC group compared to 9 x 10(4) per heart in the SP group). These results support the hypotheses that rodent and human-bone-marrow derived side population cells are capable of acquiring a cardiac fate and that human bone-marrow-derived side population cells are superior to unfractionated bone marrow mononuclear cells in augmenting left ventricular systolic function following cryoinjury.

Laparoscopic inguinal hernia repair: over a thousand convincing reasons to go on.

BACKGROUND: Laparoscopic hernia repair has emerged as an effective alternative method for treating inguinal hernias. The ability to provide this service as day surgery or short-stay (23-h stay) treatment makes it an attractive method in this age of resource limitations. The technique is cost-effective when the use of disposable instruments is kept to a minimum. METHODS: Our team performed laparoscopic transabdominal pre-peritoneal (TAPP) inguinal hernia repair on 1,389 patients in the period from September 1999 to March 2007. We take this opportunity to discuss the lessons we have learnt and our experience and views with regards to certain procedure-specific problems encountered by many of our peers. RESULTS: A variety of commonly encountered inguinal and groin hernias were treated by TAPP with good results, minimal morbidity (4.39%) and one mortality. We have discussed our views on technical aspects of the procedure, such as the extent of pre-peritoneal dissection, methods of treating the hernia sac, the size and number of pre-peritoneal prosthetic meshes deployed, fixation of the mesh and reconstitution of the peritoneum. Our views on the causes and our strategies for managing complications such as seroma formation (3.09%), recurrence (0.29%), bleeding (0.36%) and mesh infection (0.14%) have been outlined. We believe that incidental hernias (N=150) discovered during initial laparoscopy can be safely treated with no added morbidity, provided the patients' views and consent regarding the treatment are given due consideration. CONCLUSION: Laparoscopic TAPP hernia repair has proven to be an efficient method of providing treatment for groin hernias. Our experience over the last eight years has given us over a thousand convincing reasons to continue working and improving upon this service.

Prevention of trocar site incisional hernia following laparoscopic ventral hernia repair.

BACKGROUND AND OBJECTIVES: Trocar-site incisional hernia following laparoscopic ventral hernia repair is reported to have a relatively high incidence. The main reasons are trocar diameter and design, pre-existing fascial defects, and some operation- and patient-related factors. The aim of this article to show a new technique of ventral hernia repair that could prevent trocar site incisional hernia. METHODS: After establishing the pneumoperitoneum, three 5-mm ports are inserted in positions according to the site and size of the hernia. The procedure begins by dissection of the adhesions of bowel loops or omentum (if any) from the hernia to clear a good margin for mesh coverage. Then a single 10-mm to 15-mm port (mesh insertion port) is inserted in the center of the ventral hernia depending on the size of the mesh. The mesh is fixed in position with a 5-mm tacker. The peritoneum and underlying superficial fascia are carefully closed before closing the skin. RESULTS: A total of 35 patients were recruited for this method. The mean hospital stay was 1.5 days, the mean age was 50.35 years and the mean operative time was 40 minutes. In all patients, 10x15-cm ePTFE was used. No single incidence of trocar-site incisional hernia occurred during a mean follow-up of 2 years. Three (8.57%) patients developed complications and no mortality was reported. CONCLUSION: The mesh introduction through the port, which is situated at the center of the hernia defect is a simple, cost-effective technique and will prevent trocar-site incisional hernia.