Keloids: A viral hypothesis.

The triggering cause of keloid formation on a healing wound remains an enigma. In fact, the hypotheses put forward so far to explain this phenomenon seem inconsistent with some clinical features of the disease. The recently established bonds between infectious agents and some pathologies of unknown origin such as peptic ulcer disease, Kaposi's sarcoma or cervical cancer among others led us to consider a potential infectious origin for keloids. This paper presents an infection-based hypothesis (specifically, a viral hypothesis) intended to account for most of their clinical features. Essentially, we hypothesize that healthy individuals carrying a virus, whether known or unknown, associated to some adjuvant, and having some genetic susceptibility, may develop keloids during the scar maturation process in the following manner: the virus would make the bone marrow or lymphatic system its reservoir, residing there in a silent state, and reach the wound via two different mechanisms. The primary mechanism might use an internal circuit through which the viral genome would be transported from its myeloid reservoir to the wound via bone marrow or circulating fibrocytes chemotactically attracted to the damaged skin region. The secondary mechanism might involve an external circuit by which infecting virions via saliva would be shed in the wound directly (preferentially in the sternal or deltoid region) or indirectly (other satellite regions) via the hands or some fomites. A combination of both mechanisms might also be possible. Once in the wound, the virus would switch from a silent state to a latent state by effect of some chemical stimulus probably generated during the tissue repair process; in the new state, the transcription of some of the powerful viral proteins might cause thorough derailment of the normal repair process. As a result, keloid growth might depend both on individual susceptibility and on the viral load deposited into the wound; the greater the susceptibility and viral load were, the more markedly the keloid would develop and the more aggressive it would be.

Influence of marginal donors on liver preservation injury.

PURPOSE: The purpose of this study was to assess the accumulated effects of marginal donor quality factors on liver preservation injury (LPI). METHODS: The most recent 400 consecutive liver transplantations at our institution were reviewed. Marginal liver donor criteria included the following: older than 60 years, an intensive care unit stay under ventilatory support for more than 4 days, a cold ischemia time more than 14 hr, high inotropic drug use, prolonged hypotensive episodes for more than 1 hr and less than 60 mm Hg, a peak serum sodium more than 155 mEq/L, and high levels of bilirubin, alanine transferase, or amino transferase. The type of steatosis (macrovesicular or microvesicular) was quantified in four categories: no steatosis, mild (<30%), moderate (30-60%), and severe (> 60%). LPI was stratified histologically in four levels: no damage, mild, moderate, and severe injury. These variables were included in a logistic regression analysis for prediction of the probability of the appearance of LPI. RESULTS: Five variables showed an independent influence on LPI: high inotropic drug use (odds ratio [OR]=1.56), donor age (OR=1.017 per year), moderate to severe macrovesicular steatosis (OR=3.63), cold ischemia time (OR=1,109 per hour), and prolonged stay in an intensive care unit (OR=1.79). Severe LPI was present in 32.7% of the grafts from donors without any factor of the model; in 46.8% from donors with one factor (P =0.09); in 66.2% from donors with two factors (P =0.006); and in 78.3% from donors with at last three factors (P =0.002) (global P=0.0001; chi2 =21.8). CONCLUSIONS: LPI can be potentially predicted based on donor and graft conditions. Accumulation of factors is correlated with an increased effect on LPI.

Melatonin reduces apoptosis and necrosis induced by ischemia/reperfusion injury of the pancreas.

The pancreas is highly susceptible to the oxidative stress induced by ischemia/reperfusion (IR) injury leading to the generation of acute pancreatitis. Melatonin has been shown to be useful in the prevention of the damage by ischemia-reperfusion in liver, brain, myocardium, gut and kidney. The aim of the study was to evaluate the cytoprotective properties of melatonin against injury induced by IR in pancreas. The obstruction of gastro-duodenal and inferior splenic arteries induced pancreatic IR in male Wistar rats. Melatonin was intraperitoneally administered before or/and after IR injury. The animals were killed at 24 and 48 hr after reperfusion and there were evaluated parameters of oxidative stress (lipoperoxides, superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione), glandular endocrine and exocrine function (lipase, amylase, insulin) and cell injury (apoptosis and necrosis). The IR induced a marked enhancement of oxidative stress and impaired pancreatic function. The histological analysis showed that IR induced acute pancreatitis with the accumulation of inflammatory infiltrate, disruption of tissue structure, cell necrosis and hemorrhage. Melatonin administration before or after pancreatic IR prevented all tissue markers of oxidative stress, biochemical and histological signs of apoptosis and necrosis, and restored glandular function. No histological signs of pancreatitis were observed 48 hr after reperfusion in 80% of the animals treated with melatonin, with only a mild edematous pancreatitis being observed in the remaining rats. Preventive or therapeutic administration of melatonin protected against the induction of oxidative stress and tissue injury, and restored cell function in experimental pancreatic IR in rats.

Radical surgery-peritonectomy and intraoperative intraperitoneal chemotherapy for the treatment of peritoneal carcinomatosis in recurrent or primary ovarian cancer.

BACKGROUND AND OBJECTIVES: Advanced ovarian cancer typically spreads in a diffuse intra-abdominal fashion. This characteristic suggests that combined radical surgery and intraperitoneal chemotherapy may be a useful treatment procedure. The purpose of this study was to review patients submitted to surgical debulking and hyperthermic intraoperative intraperitoneal chemotherapy (HIIC) and to evaluate the potential prognostic survival factors for advanced epithelial ovarian cancer in our center. METHODS: A series of patients (N = 33) diagnosed of peritoneal carcinomatosis for epithelial ovarian cancer (stage III) from January 1997 to December 2004 submitted to radical surgery-peritonectomy and HIIC with paclitaxel was included in this study; 19 primary ovarian cancer and 14 recurrent ovarian cancer. RESULTS: Cytoreduction R0 (P = 0.018) and negative lymph nodes (P = 0.005) were covariables for major prognostic survival. Patients with optimal cytoreduction R0 obtained survival rates of 63% at 5 years in recurrent ovarian cancer and 60% in primary ovarian cancer, 71% and 63%, respectively with associated subtotal infra-abdominal peritonectomy, and even better results if negative lymph nodes. CONCLUSIONS: Radical surgery-peritonectomy with HIIQ has been shown to be a surgical procedure with high tolerability, low morbimortality, enhanced survival, and prolonged disease-free interval in patients with peritoneal carcinomatosis so much for recurrent or primary ovarian cancer.

Assignment of steatotic livers by the Mayo model for end-stage liver disease.

Prognosis after liver transplantation depends on a combination of recipient and donor variables. The purpose of this study is to define an allocation system of steatotic donor livers relative to recipient model for end-stage liver disease (MELD) score. We reviewed 500 consecutive OLT, computing the MELD score for each recipient. Fatty infiltration in grafts was categorized in no steatosis, 10-30%, 30-60% and > or = 60% steatosis. MELD score did not affect preservation injury and graft dysfunction, which were increased with fat content. Recipient and graft survivals lowered when increasing MELD score. Outcome in low-risk recipients (MELD < or = 9) was not altered with steatosis, except those with > or = 60%. Survival functions in moderate-risk recipients (MELD 10-19) were moderately affected with 10-30% steatosis and severely with those with >30. Exactly 30-60% steatotic grafts work poorly in high-risk recipients (MELD > or = 20), and very poorly with > or = 60% steatosis. Prognosis of candidates is optimally influenced when divergence of recipient-donor risks is presented.

Melatonin prevents experimental liver cirrhosis induced by thioacetamide in rats.

Liver cirrhosis is a critical stage of chronic liver diseases that can produce liver failure, portal hypertension and hepatocarcinoma. Sustained oxidative stress plays a key role in cell damage and fibrosis induced during liver cirrhosis. We evaluated the effect of oxidative stress regulation by melatonin on the development of parenchymal destruction and stellate cell activation in experimental liver cirrhosis. Melatonin was administered to rats with liver cirrhosis induced by thioacetamide (TAA) for 1 or 3 months. Liver injury was assessed by serological analysis, as well as hematoxylin-eosin staining and the in situ apoptosis detection assay in liver sections. Oxidative stress was evaluated by lipoperoxide and reduced glutathione levels, and by the measurement of catalase and superoxide dismutase activities in liver and serum respectively. The activation of stellate cells was evaluated by alpha-smooth muscle actin expression in liver sections. Our results showed that TAA induced oxidative stress with extensive tissue damage and enhanced alpha-smooth muscle actin expression in liver. Melatonin prevented the oxidative stress-related changes associated with TAA toxicity. In conclusion, the study showed that melatonin prevents the tissue damage and fibrosis associated with TAA-induced liver cirrhosis in rats.