The aging process and potential interventions to extend life expectancy

Aging is commonly defined as the accumulation of diverse deleterious changes occurring in cells and tissues with advancing age that are responsible for the increased risk of disease and death. The major theories of aging are all specific of a particular cause of aging, providing useful and important insights for the understanding of age-related physiological changes. However, a global view of them is needed when debating of a process which is still obscure in some of its aspects. In this context, the search for a single cause of aging has recently been replaced by the view of aging as an extremely complex, multifactorial process. Therefore, the different theories of aging should not be considered as mutually exclusive, but complementary of others in the explanation of some or all the features of the normal aging process. To date, no convincing evidence showing the administration of existing “anti-aging” remedies can slow aging or increase longevity in humans is available. Nevertheless, several studies on animal models have shown that aging rates and life expectancy can be modified. The present review provides an overlook of the most commonly accepted theories of aging, providing current evidence of those interventions aimed at modifying the aging process.     

Special problems in the surgical treatment of megaesophageal cardial achalasia. A clinical case]

The paper report the case of a patient brought to the Authors' attention suffering from megaesophageal cardial achalasia who had already undergone gastroduodenal resection according to BII. It was considered worthwhile to report this case due to the problems which arose concerning the choice of a thoracic rather than abdominal route owing to the impossibility of associating cardiomyotomy with anti-reflux plastica surgery because of the reduced dimensions of the stomach.     

Evidence for the involvement of SDF-1 and CXCR4 in the disruption of endothelial cell-branching morphogenesis and angiogenesis by TNF-alpha and IFN-gamma

Vigorous inflammatory responses are associated with tissue damage, particularly when toxic levels of inflammatory cytokines are produced. Despite proangiogenic factors being present early at sites of inflammation, vascular repair occurs toward the end of the inflammatory response, suggesting modulation of the proangiogenic response. Endogenous inhibitors of angiogenesis induced during acute inflammation are poorly characterized. Here, we looked for endothelial cell-derived modulators of angiogenesis that may account for delayed neovascularization during inflammation. Gene profiling of endothelial cells showed that the inflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interferon-gamma (IFN-gamma) selectively promote expression of the antiangiogenic molecules, IFN-inducible protein-10, monokine induced by IFN-gamma, tryptophanyl-tRNA synthetase, and tissue inhibitor of metalmetalloproteinase-1, and inhibit expression of the proangiogenic molecules, platelet-endothelial cell adhesion molecule-1, vascular endothelial growth factor receptor-2, stromal cell-derived factor-1 (SDF-1), collagen type IV, endothelial cell growth factor-1, and carcinoembryonic antigen-related cell adhesion molecule-1. Reduced endothelial cell expression of SDF-1 protein by TNF-alpha and IFN-gamma disrupts extracellular matrix-dependent endothelial cell tube formation, an in vitro morphogenic process that recapitulates critical steps in angiogenesis. Replacement of SDF-1 onto the endothelial cell surface reconstitutes this morphogenic process. In vivo, TNF-alpha and IFN-gamma inhibit growth factor-induced angiogenesis and SDF-1 expression in endothelial cells. These results demonstrate that SDF-1/CXC chemokine receptor-4 constitutes a TNF-alpha- and IFN-gamma-regulated signaling system that plays a critical role in mediating angiogenesis inhibition by these inflammatory cytokines.     

Interleukin-18 expression induced by Epstein-Barr virus-infected cells

Human Epstein-Barr virus (EBV)-negative Burkitt lymphomas cells usually grow as malignant subcutaneous tumors in athymic mice, but these tumors regress when the Burkitt cells are injected in conjunction with EBV-positive lymphoblastoid cells or when the Burkitt cells are transfected with the EBV latent membrane protein-1 (LMP-1) gene. Tumor regression is mediated, in part, by murine interferon gamma (IFN-gamma) and the IFN-gamma-induced murine chemokine IFN-gamma-inducible protein-10 (IP-10). The mechanisms by which EBV-LMP-1 promotes the expression of IFN-gamma has remained unclear. Here we show that murine interleukin (IL)-18 was consistently expressed in regressing Burkitt tumors but was either expressed at low levels or absent from progressively growing Burkitt tumors. By immunohistochemical methods, IL-18 protein was visualized in regressing but not in progressively growing Burkitt tumors. In contrast, IL-12 p35 and IL-12 p40 were only rarely expressed in regressing Burkitt tumors. In splenocyte cultures, EBV-infected lymphoblastoid cells and LMP-1-transfected Burkitt cells promoted the expression of IL-18 but not the expression of IL-12 p35 and IL-12 p40. A neutralizing antibody directed at murine IL-18 reduced murine IP-10 expression induced by EBV-immortalized cells in splenocyte cultures. These results provide evidence for IL-18 expression in response to a viral latency protein and suggest that IL-18 may play an important role as an endogenous inducer of IFN-gamma expression, thereby contributing to tumor regression.     

MIP-1alpha expression in tissues from patients with hemophagocytic syndrome

Hemophagocytic syndrome (HPS) is a clinicopathologic syndrome that can be precipitated by a variety of causes and is characterized by a systemic activation of macrophages, which are induced to undergo phagocytosis. Chemokines play an important role in the inflammatory cell recruitment into tissues. We examined the expression of chemokines and cytokines in tissues exhibiting histologic evidence of HPS in a variety of settings: peripheral T-cell lymphoma, three patients; nasal T/NK cell lymphoma, one patient; subcutaneous panniculitis-like T-cell lymphoma, one patient; and chronic EBV infection, one patient. Compared with control tissues, we found elevated macrophage inflammatory protein-1alpha (MIP-1alpha) and interferon-gamma (IFN-gamma) expression, but not macrophage-derived chemotactic factor (MDC) or TNF-alpha, in tissues of patients with HPS irrespective of the cause or setting. MIP-1alpha can promote macrophage chemotaxis and IFN-gamma promotes macrophage activation. Elevated expression of IP-10 and monokine induced by IFN-gamma (Mig) was also detected in tissues exhibiting features of HPS, providing an explanation for the occurrence of chemoattraction of T-cells and NK cells. Immunohistochemical analysis of tissues with evidence of phagocytic activity in that site showed MIP-1alpha characteristically localized to endothelial cells of blood vessels and splenic sinuses, lymphocytes, and macrophages. These results provide evidence for MIP-1alpha chemokine expression in tissues from patients with HPS and suggest that MIP-1alpha may play an important role in the pathogenesis of the hemophagocytic syndrome.     

Surgery of large ventral hernias. Personal experience in 1990-1997

BACKGROUND: The surgical treatment of large wall defects conventionally defined as an extension over 10 cm is discussed. The difficulty to contain the bowels that have lost law of domicile in the abdominal hollow, constitutes motive for notable increase of the endo-abdominal Pressure with serious consequences in the postoperative course and this leads to the use of prothesis meshes that allow the closing of the abdominal hollow with the Tension-Free technique. METHODS: Personal experience embraces 45 patients, with large wall defects, divided into 21 patients with overumbilical location, 14 with umbilical location, 10 with periumbelical location; a simple suture has been used in 7 cases, the reconstruction of the wall according to Stoppa in 36 cases and the apposition of Goretex net internally and Marlex net externally in 2 cases. RESULTS: There have been neither mortality, neither recidivists of illness, but only some complications: 9 cases of superficial infection, 1 case of intestinal occlusion and 2 of subcutaneous seroma. CONCLUSIONS: According to their experience and wide literature review, the authors draw some conclusions: an accurate toilet and a careful evaluation of the respiratory functionality are fundamental; it's necessary to postpone surgical intervention in presence of local inflammation and, where this is improrogable it's opportune to avoid the use of prothesis meshes or refold on readsorbible prothesis; special care must be taken to the hemostasis and an aspirative drain for 24-48 hrs preserves from the risk of postoperative hematomas and following local infections. The submuscular mesh permits a Tension-Free suture and for this reason it would have nowdays a more extensive use. Finally it's pointed out the choice of a PTFEe mesh in contact with the intestinal skein.     

Spontaneous retroperitoneal hematoma: a case report

The A.A. present a case report of retroperitoneal spontaneous hematoma and put in evidence the difficulties in making an etiopathogenetic diagnosis of spontaneous renal cyst rupture. The patient was a 72 years old man admitted to the hospital in emergency for a painful ipogastric syntomatology and biliary vomit. The ecography showed a distanced gallbladder and the endoscopy evidenced a duodenal stenosis with compression of the gastric posterior wall, so that we were initially directed towards a pancreatic tumor even if the modest increase of the serum bilirubinemy and mostly the fact that direct component was almost normal, gave us strong doubts. The spiral TC gave finally the diagnosis of retroperitoneal hematoma and the presence of a bilateral polycystic kidney with several subcapsular cyst, let us suggest, as well as the anamnestic report of a physical stress, a renal origin of the bleeding. A wild literature review did not evidence other similar cases, but the ecclusion of other possible causes of retroperitoneal hematoma, suggested this conclusion.     

Chronic persistent Epstein-Barr virus infection of natural killer cells and B cells associated with granular lymphocytes expansion

B lymphocytes and epithelial cells are the only cell types known to be infected with Epstein-Barr virus (EBV) in normal individuals. Rarely, EBV also infects other cells, including natural killer (NK) cells, almost always in the context of fatal leukaemias or lymphoproliferative disorders. We report on a 6-year-old previously healthy girl who developed fevers and liver function abnormalities for 3 months. The peripheral blood revealed an abnormal expansion of large granular lymphocytes, comprising 24% of the white blood cells. Flow cytometric analysis of the peripheral blood mononuclear cells showed an abnormal increase of CD16-positive NK cells, 62% of which were EBV-infected by in situ EBER-1 hybridization. The circulating B cells were normal in number, but 18% were infected with EBV by in situ EBER-1 hybridization. Approximately 2 years after resolution of all symptoms and continued good health, 35% of the circulating mononuclear cells were EBV-infected, indicative of persistent expansion of EBV-infected cells. We conclude that abnormal expansions of EBV-infected NK and B cells can be associated with a chronic benign course.     

HIV-1 Tat enhances Kaposi sarcoma-associated herpesvirus (KSHV) infectivity

The high frequency of Kaposi sarcoma (KS) in immunodeficiency states, particularly in patients with AIDS, has been attributed to increased replication of KS-associated herpesvirus (KSHV), a necessary cofactor for KS development. However, experimental KSHV infection of endothelial lineage cells that compose KS lesions has been difficult even in the absence of immune cells. Here we show that HIV-1 Tat protein can directly promote KSHV transmission. Full-length HIV-1 Tat and a 13-amino-acid peptide corresponding to the basic region of Tat specifically enhances the entry of KSHV into endothelial and other cells, presenting evidence for an active role of HIV-1 in the development of KSHV-associated diseases. These results can explain why AIDS-KS is more frequent and clinically more aggressive than KS in other immunodeficiency states.