Peripheral nerve morphogenesis induced by scaffold micropatterning

Several bioengineering approaches have been proposed for peripheral nervous system repair, with limited results and still open questions about the underlying molecular mechanisms. We assessed the biological processes that occur after the implantation of collagen scaffold with a peculiar porous micro-structure of the wall in a rat sciatic nerve transection model compared to commercial collagen conduits and nerve crush injury using functional, histological and genome wide analyses. We demonstrated that within 60 days, our conduit had been completely substituted by a normal nerve. Gene expression analysis documented a precise sequential regulation of known genes involved in angiogenesis, Schwann cells/axons interactions and myelination, together with a selective modulation of key biological pathways for nerve morphogenesis induced by porous matrices. These data suggest that the scaffold's micro-structure profoundly influences cell behaviors and creates an instructive micro-environment to enhance nerve morphogenesis that can be exploited to improve recovery and understand the molecular differences between repair and regeneration.     

Thrombectomy and surgical reconstruction for extensive iliocaval thrombosis in a patient with agenesis of the retrohepatic vena cava and atresia of the left renal vein

In 80% of the patients presenting with deep-venous thrombosis (DVT), a risk factor can be identified. An absent or hypoplastic infrarenal vena cava is a rare risk factor for DVT in young adults. In these cases, the prevalence of congenital anomalies of the inferior vena cava (IVC) is estimated at 0.5% of the general population, up to 5% in young people. The association with coagulopathy increases the risk of DVT. We report a case of a young man who presented with a massive caval and iliofemoral-popliteal thrombosis in presence of the agenesis of retrohepatic inferior vena cava and atresia of the left renal vein. Open thrombectomy and caval reconstruction with a polytetrafluoroethylene graft were performed. Surgical option with vein reconstruction was preferred to prevent new episodes of thrombosis and the risk of acute renal failure.     

Prognosis of patients with spontaneous rupture of hepatocellular carcinoma in cirrhosis

The treatment of cirrhotic patients with spontaneous rupture of hepatocellular carcinoma (HCC) is controversial and largely dependent on general conditions of the patients and compensation of the underlying cirrhosis. We retrospectively reviewed clinical, imaging and surgical records of 24 consecutive cirrhotic patients (17 males, 7 females; age range 52–88 years) with hemoperitoneum from spontaneous rupture of HCC observed from June 2004 to January 2010 at our Institution. When indicated, patients were referred to surgery or trans-arterial embolization (TAE). Advanced decompensated patients were conservatively treated and clinically followed up. Spontaneous rupture of HCC was assessed by aspiration of bloody ascites at paracentesis in all cases. The presence of large blood-clots over HCC and liver surface at US and/or CT was considered a specific sign of ruptured HCC in 14 cases. In two out of four patients who underwent TAE active bleeding from tumor surface could be demonstrated. In 2 cases, the active hemorrhage from the HCC surface could be assessed by contrast-enhanced ultrasonography. Four out of 24 patients underwent surgery. Three out of four of these patients died within 2 weeks, 8 months, and 20 months after operation, respectively. The remaining patient is still alive at 52 months follow-up. Four patients underwent TAE and died at 1, 2, 6 and 10 months after treatment, because of recurrent peritoneal bleeding and/or liver failure. Sixteen patients with ruptured HCC in the advanced Child C cirrhosis were treated conservatively with blood derivative transfusion and with procoagulant drugs. All patients, but one died within 2–18 days. One patient survived the acute hemorrhage from ruptured HCC and died of liver failure after 3 months. We concluded that spontaneous rupture of HCC is usually a fatal event in patients with poor liver function, even after successful TAE. In compensated patients, timely surgical treatment can result in long term and even tumor-free survival of the patient.     

Balance exercise in patients with chronic sensory ataxic neuropathy: a pilot study

Although exercise therapy is considered part of the treatment of neuropathic patients, and somatosensory input is essential for motor learning, performance and neural plasticity, rehabilitation of patients with sensory ataxia has received little attention so far. The aim of this prospective pilot study was to explore the short‐ and medium‐term efficacy of a 3‐week intensive balance and treadmill exercise program in chronic ataxic neuropathy patients; 20 consecutive patients with leg overall disability sum score (ODSS‐leg) ≥2, absent/mild motor signs, clinical and therapeutic stability ≥4 months were enrolled. Evaluations were done at baseline, at the end of treatment and at 3‐ and 6‐month follow‐up. Outcome measurements included: ODSS‐leg, Berg balance scale, 6‐min walk distance, and the functional independence measure (FIM) scale. The short‐form‐36 health status scale (SF‐36) was used to measure health‐related quality of life (HRQoL). ODSS‐leg improved significantly compared with baseline, 3 weeks, 3 months (primary outcome), and 6 months follow‐up. A significant improvement in all functional secondary outcome measurements and in some SF‐36 subscales was also observed. This pilot study suggests that balance exercise is safe and well tolerated and might be effective in ameliorating disability and HRQoL in patients with chronic peripheral sensory ataxia.     

Diagnostic value of troponin T for alterations in left ventricular mass and function in dialysis patients

BACKGROUND: Cardiac troponin T (cTnT) is related to left ventricular (LV) mass in patients with end-stage renal disease (ESRD). Furthermore, cTnT reflects the severity of systolic dysfunction in patients with heart diseases. We tested the diagnostic value of cTnT for left ventricular hypertrophy (LVH) and LV systolic dysfunction in a large group of clinically stable hemodialysis patients without heart failure. RESULTS: CTnT was significantly (P < 0.001) higher in patients with LVH than in those with normal LV mass. In a multiple logistic regression model, adjusting for potential confounders (including cardiac ischemia), systolic pressure and cTnT (both P = 0.003) were the strongest correlates of LVH. Similarly, cTnT was significantly higher (P = 0.005) in patients with systolic dysfunction than in those with normal LV function and in a multiple logistic regression model cTnT ranked as the second independent correlate of this alteration after male sex. Serum cTnT had a high positive prediction value for the diagnosis of LVH (87%) but its negative prediction value was relatively low (44%). The positive predictive value of cTnT for LV dysfunction was low (25%) while its negative predictive value was high (93%). A combined analysis including systolic pressure (for the diagnosis of LVH) and sex (for the diagnosis of LV systolic dysfunction) augmented the diagnostic estimates to an important extent (95% positive prediction value for LVH and 98% negative prediction value for LV systolic dysfunction). CONCLUSIONS: CTnT has a fairly good diagnostic potential for the identification of LVH and for the exclusion of LV systolic dysfunction in patients with ESRD without heart failure. This marker may be useful for the screening of alterations in LV mass and function in clinically stable hemodialysis patients.     

Control of aerostasis in pulmonary metastasectomy by precision resection. Standard technique versus fibrin glue modification

The control of aerostasis after performing non-anatomical pulmonary resections constitutes a serious problem. The presence of an air leak in the postoperative period requires a prolonged thoracic drainage and consequently a longer hospital stay. The aim of our study was to evaluate the usefulness of fibrin glue and its effectiveness in the prevention of air leaks. At the Department of Thoracic Surgery of the National Cancer Institute of Milan, we conducted a case-control study in 90 patients submitted to metastasectomy for secondary lung cancer, removing multiple small nodules < or = 1.5 cm using the precision resection technique. We divided the patients into two groups, both of 45 subjects: group 1 treated with fibrin glue and group 2 submitted to cauterization of the pulmonary parenchyma. The patient characteristics were well matched for age, type of approach and operation, number of resections performed and type of pathology. The assessment parameters investigated were the duration of the air leak, expected complications, drainage time and length of hospital stay. In group 1 we performed fewer than 5 precision resections in 21 cases, from 5 to 10 in 16, and more than 10 in 8. In group 2 we executed fewer than precision resections in 21 cases, from 5 to 10 in 17, and more than 10 in 7. In group 1 the duration of the air leak was 2.93 +/- 1.91 days as against 6.95 +/- 7.01 days in group 2 (p = 0.000). In group 1 we had one complication (2%) (a long-term air leak lasting > 10 days), while in group 2 we had a long-term air leak in 11 cases (24%) (p = 0.000). Mean thoracic drainage time was 4.22 +/- 1.43 days in group 1, and 8.13 +/- 7.37 in group 2 (p = 0.000). The mean postoperative hospital stay was 6.22 +/- 1.43 days in group 1 compared to 10.13 +/- 7.37 days in group 2 (p = 0.000). In the group of patients treated with fibrin glue we obtained a significant reduction in drainage time, complications and postoperative hospital stay. The results of our experience show that the use of fibrin glue in non-anatomical resections with a high risk of developing air leakage is effective in reducing the expected complications, with a favourable impact also on the quality of life of patients with metasases.     

Overview on the mechanisms of drug-induced liver cell death

Drug-induced hepatotoxicity is a significant and still unresolved clinical problem. The limitation in current knowledge regarding mechanisms of hepatic toxicity renders most of the preclinical review process failing and most of drug-induced hepatic injury remains unpredictable. Current knowledge on the mechanisms of drug-induced liver cell death is reviewed here. The intervention of both intra- and extracellular factors in determining the appearance of drug-induced cell apoptosis or necrosis is also discussed. Finally, the role of both mitochondria and non parenchymal cells are reviewed with respect to approaches useful to manage drug-induced liver injury.