Local delivery of the Neuregulin1 receptor ecto-domain (ecto-ErbB4) has a positive effect on regenerated nerve fiber maturation.

The Neuregulin/ErbB system plays an important role in the peripheral nervous system, under both normal and pathological conditions. We previously demonstrated that expression of soluble ecto-ErbB4, the released extracellular fragment of the ErbB4 receptor, stimulated glial cell migration in vitro. In this study we examined the possibility of manipulating this system in vivo in order to improve injured peripheral nerve regeneration. Transected rat median nerves of adult female Wistar rats were repaired with a 10-mm-long graft made by muscle-in-vein combined nerve guide previously transduced with either the adeno-associated viral (AAV) vector AAV2-LacZ or AAV2-ecto-ErbB4. Autologous nerve grafts were used as control. Both stereological and functional analyses were performed to assess nerve regeneration. Data show that delivery of soluble ecto-ErbB4 by gene transfer in the muscle-in-vein combined nerve guide has a positive effect on fiber maturation, suggesting that it could represent a potential tool for improving peripheral nerve regeneration.

Feasibility and reproducibility of spleen transient elastography and its role in combination with liver transient elastography for predicting the severity of chronic viral hepatitis.

Liver transient elastography (L-TE) is a reliable, noninvasive predictor of disease severity in chronic liver disease of viral aetiology (CLD). Owing to the relationships among severity of CLD, portal hypertension and spleen involvement, the assessment of splenic stiffness (S-TE) may have an added value in staging CLD. Of 132 CLD patients of viral aetiology, 48 with myeloproliferative disorders (MD) and 64 healthy volunteers (HV), were concurrently investigated by both L-TE and S-TE. Liver disease severity was staged by liver biopsy (LB; Metavir) taken concurrently with TE examination and upper gastrointestinal tract endoscopy for gastro-oesophageal varices. The S-TE inter-observer agreement was analysed by an intra-class correlation coefficient (ICC); L-TE and S-TE accuracy was evaluated by receiver operating characteristic (ROC) curve analysis. Logistic regression analysis assessed the independent effect of L-TE and S-TE as predictors of hepatic fibrosis stage. S-TE failed in 22 CLD (16.6%), 12 (25%) MD and 12 (18%) HV. In the three groups, the ICC was 0.89 (0.84-0.92), 0.90 (0.85-0.94) and 0.86(0.80-0.91), respectively. In the CLD group, L-TE and S-TE independently predicted significant fibrosis (OR 5.2 and 4.6) and cirrhosis (OR 7.8 and 9.1), but at variance from L-TE, S-TE was independent from liver necroinflammation and steatosis. The NPV of S-TE for gastro-oesophageal varices was 100% using a 48 kPa cut-off. In CLD, spleen stiffness alone or in combination with hepatic stiffness can be reliably and reproducibly assessed by TE with the added value of improving the noninvasive diagnosis of severe liver disease and excluding the presence of oesophageal varices.

Conceptual design of a Doppler spectrometer for 102 m/s cross-field flows in tokamak divertors.

The cross-field transport in the scrape-off-layers (SOLs) and divertors in tokamaks is of a similar size to the poloidal component of the parallel flow, thereby significantly impacting the plasma transport there. However, its direct observation has been challenging because the drift velocity (102-103 m/s) is significantly below the detection limit of conventional diagnostics. To realize cross-field ion flow measurement, a variety of systematic uncertainties in the system must be narrowed down. Here, we develop a conceptual design of the Doppler spectrometry that enables us to measure the impurity flows with 102-m/s accuracy based on an in situ wavelength-calibration technique developed in the astrophysics field, the iodine-cell method. We discuss its properties and applicability. In particular, the scaling relation between wavelength accuracy and various spectroscopic parameters is newly presented, which suggests the high importance of the wavelength resolution of the system. Based on transport simulations for the JT-60SA divertor, the feasibility of the system is assessed.

Improved accuracy and robustness of electron density profiles from JET's X-mode frequency-modulated continuous-wave reflectometers.

JET's frequency-modulated continuous wave (FMCW) reflectometers have been operating well with the current design since 2005, and density profiles have been automatically calculated intershot since then. However, the calculated profiles had long suffered from several shortcomings: poor agreement with other diagnostics, sometimes inappropriately moving radially by several centimeters, elevated levels of radial jitter, and persistent wriggles (strong unphysical oscillations). In this research, several techniques are applied to the reflectometry data analysis, and the shortcomings are significantly improved. Starting with improving the equilibrium reconstruction that estimates the background magnetic field, adding a ripple correction in the reconstructed magnetic field profile, and adding new inner-wall reflection positions estimated through ray-tracing, these changes not only improve the agreement of reconstructed profiles to other diagnostics but also solve density profile wriggles that were present during band transitions. Other smaller but also persistent wriggles were also suppressed by applying a localized correction to the measured beat frequency where persistent oscillations are present. Finally, the burst analysis method, as introduced by Varela et al. [Nucl. Fusion 46 S693 (2006)], has been implemented to extract the beat frequency from stacked spectrograms. Due to the strong suppression of spurious reflections, the radial jitter that sometimes would span several centimeters has been strongly reduced. The stacking of spectrograms has also been shown to be very useful for stacking recurring events, like small gas puff modulations, and extracting transport coefficients that would otherwise be below the noise level.

Effect of vascular endothelial growth factor gene therapy on post-traumatic peripheral nerve regeneration and denervation-related muscle atrophy.

Functional recovery after peripheral nerve injury depends on both improvement of nerve regeneration and prevention of denervation-related skeletal muscle atrophy. To reach these goals, in this study we overexpressed vascular endothelial growth factor (VEGF) by means of local gene transfer with adeno-associated virus (AAV). Local gene transfer in the regenerating peripheral nerve was obtained by reconstructing a 1-cm-long rat median nerve defect using a vein segment filled with skeletal muscle fibers that have been previously injected with either AAV2-VEGF or AAV2-LacZ, and the morphofunctional outcome of nerve regeneration was assessed 3 months after surgery. Surprisingly, results showed that overexpression of VEGF in the muscle-vein-combined guide led to a worse nerve regeneration in comparison with AAV-LacZ controls. Local gene transfer in the denervated muscle was obtained by direct injection of either AAV2-VEGF or AAV2-LacZ in the flexor digitorum sublimis muscle after median nerve transection and results showed a significantly lower progression of muscle atrophy in AAV2-VEGF-treated muscles in comparison with muscles treated with AAV2-LacZ. Altogether, our results suggest that local delivery of VEGF by AAV2-VEGF-injected transplanted muscle fibers do not represent a rational approach to promote axonal regeneration along a venous nerve guide. By contrast, AAV2-VEGF direct local injection in denervated skeletal muscle significantly attenuates denervation-related atrophy, thus representing a promising strategy for improving the outcome of post-traumatic neuromuscular recovery after nerve injury and repair.

Use of poly(DL-lactide-ε-caprolactone) membranes and mesenchymal stem cells from the Wharton's jelly of the umbilical cord for promoting nerve regeneration in axonotmesis: in vitro and in vivo analysis.

Cellular systems implanted into an injured nerve may produce growth factors or extracellular matrix molecules, modulate the inflammatory process and eventually improve nerve regeneration. In the present study, we evaluated the therapeutic value of human umbilical cord matrix MSCs (HMSCs) on rat sciatic nerve after axonotmesis injury associated to Vivosorb® membrane. During HMSCs expansion and differentiation in neuroglial-like cells, the culture medium was collected at 48, 72 and 96 h for nuclear magnetic resonance (NMR) analysis in order to evaluate the metabolic profile. To correlate the HMSCs ability to differentiate and survival capacity in the presence of the Vivosorb® membrane, the [Ca(2+)]i of undifferentiated HMSCs or neuroglial-differentiated HMSCs was determined by the epifluorescence technique using the Fura-2AM probe. The Vivosorb® membrane proved to be adequate and used as scaffold associated with undifferentiated HMSCs or neuroglial-differentiated HMSCs. In vivo testing was carried out in adult rats where a sciatic nerve axonotmesis injury was treated with undifferentiated HMSCs or neuroglial differentiated HMSCs with or without the Vivosorb® membrane. Motor and sensory functional recovery was evaluated throughout a healing period of 12 weeks using sciatic functional index (SFI), extensor postural thrust (EPT), and withdrawal reflex latency (WRL). Stereological analysis was carried out on regenerated nerve fibers. In vitro investigation showed the formation of typical neuroglial cells after differentiation, which were positively stained for the typical specific neuroglial markers such as the GFAP, the GAP-43 and NeuN. NMR showed clear evidence that HMSCs expansion is glycolysis-dependent but their differentiation requires the switch of the metabolic profile to oxidative metabolism. In vivo studies showed enhanced recovery of motor and sensory function in animals treated with transplanted undifferentiated and differentiated HMSCs that was accompanied by an increase in myelin sheath. Taken together, HMSC from the umbilical cord Wharton jelly might be useful for improving the clinical outcome after peripheral nerve lesion.

Transient elastography predicts fibrosis progression in patients with recurrent hepatitis C after liver transplantation.

OBJECTIVE: Transient elastography (TE) allows non-invasive evaluation of the severity of liver disease in patients with chronic hepatitis C. This procedure, however, warrants further validation in the setting of liver transplantation (LT), including patients under follow-up for recurrent hepatitis C. SETTING: Tertiary referral hospital. PATIENTS: 95 patients (75 males) transplanted for end-stage liver disease due to hepatitis C virus. INTERVENTIONS: Paired liver biopsy (LB) and TE were carried out 6-156 (median, 35) months after LT. 40 patients with recurrent hepatitis C sequentially evaluated 6-21 months apart. MAIN OUTCOME MEASURES: Clinical, laboratory and graft histological features influencing TE results. RESULTS: Median TE values were 7.6 kPa in the 90 patients with a successful TE examination, being 5.6 kPa in the 30 patients with Ishak fibrosis score (S) of 0-1, 7.6 kPa in the 38 with S2-3; 16.7 kPa in the 22 with S4-6, (p < 0.0001). Areas under the ROC curves were 0.85 (95% CI, 0.76 to 0.92) for S > or = 3, 0.90 (95% CI, 0.82 to 0.95) for S > or = 4 with 7.9 and 11.9 kPa optimal TE cut-off (81% and 82% sensitivity, 88% and 94% negative predictive value, respectively). Fibrosis, necroinflammatory activity and higher than 200 IU/l gamma-glutamyl transpeptidase levels independently influenced TE results. During post-LT follow-up, TE results changed in parallel with grading (r = 0.63) and staging (r = 0.71), showing 86% sensitivity and 92% specificity in predicting staging increases. CONCLUSIONS: TE accurately predicts fibrosis progression in LT patients with recurrent hepatitis C, suggesting that protocol LB might be avoided in patients with improved or stable TE values during follow-up.

SilkBridge™: a novel biomimetic and biocompatible silk-based nerve conduit.

Silk fibroin (Bombyx mori) was used to manufacture a nerve conduit (SilkBridge™) characterized by a novel 3D architecture. The wall of the conduit consists of two electrospun layers (inner and outer) and one textile layer (middle), perfectly integrated at the structural and functional level. The manufacturing technology conferred high compression strength on the device, thus meeting clinical requirements for physiological and pathological compressive stresses. In vitro cell interaction studies were performed through direct contact assays with SilkBridge™ using the glial RT4-D6P2T cells, a schwannoma cell line, and a mouse motor neuron NSC-34 cell line. The results revealed that the material is capable of sustaining cell proliferation, that the glial RT4-D6P2T cells increased their density and organized themselves in a glial-like morphology, and that NSC-34 motor neurons exhibited a greater neuritic length with respect to the control substrate. In vivo pilot assays were performed on adult female Wistar rats. A 10 mm long gap in the median nerve was repaired with 12 mm SilkBridge™. At two weeks post-operation several cell types colonized the lumen. Cells and blood vessels were also visible between the different layers of the conduit wall. Moreover, the presence of regenerated myelinated fibers with a thin myelin sheath at the proximal level was observed. Taken together, all these results demonstrated that SilkBridge™ has an optimized balance of biomechanical and biological properties, being able to sustain a perfect cellular colonization of the conduit and the progressive growth of the regenerating nerve fibers.

Employment of the mouse median nerve model for the experimental assessment of peripheral nerve regeneration.

The experimental investigation of nerve regeneration after microsurgical repair is usually carried out in rats, rather than mice, because of the larger sized peripheral nerves. Today however, the availability of genetically modified mice makes the use of this laboratory animal very intriguing for investigating nerve regeneration at a molecular level. In this study we aimed to provide a standardization of the experimental model based on microsurgical direct repair, by 12/0 suture, of the left median nerve in adult male mice. Postoperative recovery was regularly assessed by the grasping test. At day-75 postoperative, regenerated median nerve fibers were analyzed by design-based quantitative morphology and electron microscopy. Yet, sections were immuno-labelled using two axonal antibodies commonly employed for rat nerve fibers. Results indicated that functional recovery begun at day-15 and progressively increased reaching values not significantly different from normal by day-50. Quantitative morphology showed that, at day-75, the number of regenerated nerve fibers was not significantly different in comparison to controls. In contrast, differences were detected in fiber density, mean axon and fiber diameter and myelin thickness which were all significantly lower than controls. Immunohistochemistry showed that axonal markers commonly used for rat nerves studies are effective also for mouse nerves. Similar to the rat, the mouse median nerve model is superior to sciatic nerve model for the minimal impact on animal well-being and the effectiveness of the grasping test for motor function evaluation. The main limitation is the small nerve size which requires advanced microsurgical skills for performing 12/0 epineurial suturing.

Laboratory tests for evaluating the level of attenuation of bluetongue virus.

One of the most important steps when preparing a live attenuated vaccine is the assessment of the level of attenuation in target animals. It is costly and time consuming as it requires, on each occasion, a large number of susceptible animals and contained accommodation. This study assessed the consistency of the bovine foetal aorta endothelial (BFA) cell line and newborn mice for evaluating the attenuation level of BTV4, BTV9 and BTV16 Italian field isolates. Following serial passages in BHK(21c13) or Vero cell cultures, BTV attenuated clones demonstrated a reduced replication capability in the BFA cells compared to the homologous virulent strains. Similarly, following intracerebral inoculation, the attenuated clones were completely innocuous to newborn mice contrary to the homologous virulent strains which killed all animals within 10 days. Vaccines produced with the BTV9 or BTV4 attenuated clones were safe, immunogenic and capable of preventing clinical symptoms and viraemia in sheep following challenge with homologous virulent virus. The two assays may be valuable indicators of the gradual changes occurring in the BTV population leading to virus attenuation, they can predict the safety of a BTV attenuated vaccine and, in turn, reduce the number of sheep and cattle required to assess the level of attenuation attained.

Gellan Gum-based luminal fillers for peripheral nerve regeneration: an in vivo study in the rat sciatic nerve repair model.

Peripheral nerve injuries (PNI) resulting in a gap to be bridged between the transected nerve ends are commonly reconstructed with autologous nerve tissue, but there is a need for valuable alternatives. This experimental work considers the innovative use of the biomaterial Gellan Gum (GG) as a luminal filler for nerve guidance channels made from chitosan with a 5% degree of acetylation. The engineered constructs should remodel the structural support given to regenerating axons by the so-called bands of Büngner. Four different GG formulations were produced by combining varying amounts of High-Acyl GG (HA-GG) and Methacrylated GG (MA-GG). The effective porosity of the freeze-dried networks was analysed by SEM and micro-CT 3D reconstructions, while the degradation and swelling abilities were characterized in vitro for up to 30 days. The metabolic activity and viability of immortalized Schwann cells seeded onto the freeze-dried networks were also evaluated. Finally, the developed hydrogel formulations were freeze-dried within the chitosan nerve guides and implanted in a 10 mm rat sciatic nerve defect. Functional and histomorphological analyses after 3, 6, and 12 weeks in vivo revealed that although it did not result in improved nerve regeneration, the NGC25:75 formulations could provide a basis for further development of GG scaffolds as luminal fillers for hollow nerve guidance channels.

An inactivated vaccine for the control of bluetongue virus serotype 16 infection in sheep in Italy.

Because no suitable products are at the moment available to safely control the spread of BTV-16 in Europe, an inactivated vaccine was produced from the reference field isolate of bluetongue virus serotype 16. One group of six sheep was vaccinated subcutaneously with the inactivated vaccine twice, on days 0 and 28, whereas a second group of eight sheep was inoculated with saline solution and used as mock-vaccinated control animals. Seventy-eight days after the first vaccination, all sheep were inoculated subcutaneously with a suspension containing 10(6.3) TCID(50) of a virulent reference BTV-16 isolate. Apart from a transient inflammatory reaction at the injection site, no adverse effects were reported following vaccination. All vaccinated animals developed high titres (7.3-9.3log(2)(ED50%/50 microl)) of virus-specific neutralising antibodies and were resistant to challenge with BTV-16. Conversely, following challenge, control animals developed hyperthermia and long lasting high-titre viraemia.

Association of hereditary spherocytosis and idiopathic hemochromatosis. A synergistic effect in determining iron overload.

Two siblings, both splenectomized at an early age for hereditary spherocytosis, had a severe hemochromatosis develop. The human leukocyte antigen (HLA) system typing showed that they were half HLA identical. All the other members of the family who did not have evidence of hereditary spherocytosis, including those who displayed identical HLA haplotypes with the two patients, did not have any increase in iron stores. These results suggest that the two siblings are heterozygous for idiopathic hemochromatosis and that the coexistence of this condition with hereditary spherocytosis can cause a severe iron overload.

Evaluation of T and B lymphocytes in liver infiltrates of patients with chronic active hepatitis.

The proportions of T and B lymphocytes in the liver infiltrates of 23 patients with chronic active hepatitis have been determined. The results were compared with the values obtained from peripheral blood and with the presence of HB virus markers and alpha-fetoprotein in liver tissue. A group of patients with chronic liver disease other than chronic active hepatitis were studied as controls. In chronic active hepatitis the percentage of hepatic T cells was 49 +/- 8 SD (control patients 61 +/- 8) (P less than 0.01), whereas the percentage of B cells was 40 +/- 10 (control patients 18 +/- 8) (P less than 0.01). No correlation was observed between hepatic T and B cells and the presence of HB virus. The numbers of T cells in liver tissue was significantly higher, the numbers of B cells lower, in patients whose biopsies were positive for alpha-fetoprotein than in those whose biopsies were negative. In peripheral blood, only the patients with chronic active hepatitis and established cirrhosis presented lower absolute values of T cells, whereas surface immunoglobulin-positive lymphocytes were within the normal range.

A clinicopathological study of liver disease in haemophiliacs.

Chronic liver disease is not often reported in patients with haemophilia. Although a high incidence of abnormal liver function tests has been reported, the clinical significance of these findings and their relation to chronic liver disease cannot be established without a liver biopsy. The results of this procedure, carried out in 11 patients with severe haemophilia A and B, in whom SGOT had been persistently raised for three years, are reported. Five patients had chronic active hepatitis, four had chronic persistent hepatitis, one had cirrhosis, and one alcoholic hepatitis. No haemorrhagic complication followed the biopsy procedure, which was carried out in patients given prophylactic clotting factor concentrates. These results suggest that duration of abnormal liver function tests is likely to represent liver disease in haemophiliacs, and that biopsy should be considered to establish the diagnosis and plan a suitable therapeutic programme.

Geographical variation in prevalence of hepatitis B virus DNA in HBsAg negative patients.

AIMS--To study the geographical variation of the prevalence of hepatitis B virus (HBV) DNA in hepatitis B surface antigen (HBsAg) negative subjects. METHODS--A nested polymerase chain reaction (PCR) assay was used to amplify the core region of HBV. The assay was able to detect 10 molecules of a full length HBV plasmid. RESULTS--When applied to HBsAg negative paraffin wax embedded liver samples from Italy, Hong Kong, and the United Kingdom, a geographical variation in the prevalence of HBV-DNA positivity was noted. Two of 18 (11%) of Italian samples and 2/29 (6.9%) of Hong Kong samples were positive for HBV-DNA while none of the 70 cases from the United Kingdom was positive by nested PCR. Contamination by plasmid DNA was excluded using a novel method based on heteroduplex formation. One HBV-DNA positive case had idiopathic chronic active hepatitis, but the diagnoses in the other three HBV-DNA positive cases did not suggest any aetiological connection between HBV-DNA positivity and liver pathology. CONCLUSIONS--HBV-DNA could be detected in the liver tissues of a proportion of HBsAg negative subjects. The prevalence of such cases is related to the endemic rate of a geographical region. The use of HBV PCR on paraffin wax embedded tissues will be valuable for future studies on the molecular epidemiology of HBV.

Proliferating cell nuclear antigen assessed by a computer-assisted image analysis system in patients with chronic viral hepatitis and cirrhosis.

BACKGROUND: Assessment of liver cell proliferation by immunodetection of proliferating cell nuclear antigen may predict regenerative potential and survival of liver and hepatocellular carcinoma risk in patients with chronic viral hepatitis. AIM: To evaluate proliferating cell nuclear antigen status and its clinical significance in a large cohort of patients with chronic viral hepatitis and different degree of liver damage by a computer assisted imaging analysis system. MATERIALS: Liver biopsies from 358 patients with chronic hepatitis (259 males, 49 years, 63% with hepatitis C infection, 27% with hepatitis B virus, 10% with multiple infections) were studied. METHODS: Proliferating cell nuclear antigen was localised by immunoperoxidase on microwave oven pre-treated formalin-fixed, paraffin embedded sections using PC10 monoclonal antibody. Proliferating cell nuclear antigen labelling index was calculated by an automated imaging system (Immagini e Computers, Milan, Italy). RESULTS: Mean proliferating cell nuclear antigen labelling index ranged from 0.1% for patients with minimal changes to 3.6% for those with cirrhosis and hepatocellular carcinoma. Overall, proliferating cell nuclear antigen labelling index was higher in males, in older patients, in multiple infections and in hepatitis C virus compared to hepatitis B virus related cases. By linear regression analysis, proliferating cell nuclear antigen labelling index correlated with older age, male gender; higher transaminase levels, hepatitis C virus, higher histological gradIng and staging: by multivariate analysis male gender, hepatitis C virus, higher grading and staging resulted as independent variables. Both hepatitis C virus or hepatitis B virus cirrhotics had similar liver cell proliferation rate but those with hepatitis B virus had higher prevalence of liver cell dysplasia with respect to those with hepatitis C virus. CONCLUSIONS: Proliferating cell nuclear antigen labelling index was a reliable assay for assessing liver cell proliferation rate in patients with chronic viral hepatitis and correlated with liver disease severity

Ranitidine vs metoclopramide in the medical treatment of reflux esophagitis.

45 patients with symptomatic reflux esophagitis were randomly treated with either Ranitidine (150 mg b.i.d.) or Metoclopramide (10 mg t.i.d.) for six weeks. The severity of dyspeptic symptoms and the grade of endoscopic and histological esophagitis were assessed before and after treatment. Both drugs proved significantly effective in inducing symptomatic and endoscopic improvement, but Ranitidine appeared significantly superior in promoting disappearance or improvement of endoscopic esophagitis. Moreover Ranitidine was found to significantly reduce the severity of histological changes, whereas Metoclopramide was unable to do so.

[Controlled clinical trial of 2-mercapto-propionyl-glycine in chronic hepatopathies]. / Sperimentazione clinica controllata della 2-mercapto-propionil-glicina nelle epatopatie croniche

A controlled clinical trial comparing 2-Mercapto-Priopionyl-Glycine (2-MPG) plus B12 vitamin with B12 vitamin alone in chronic liver disease has been conducted in seven hospitals in Italy. Patients were divided into two groups on the basis of liver histology; group I included 26 patients showing histological evidence for chronic persistent hepatitis (C.P.H.) (according to De Groote et al.) whereas group II consisted of 54 patients with chronic aggressive hepatitis (C.A.H.) or compensated liver cirrhosis. Patients of each group were randomly allocated to 2-MPG plus B12 vitamin, or to placebo plus B12 vitamin, in a double-blind way. The drug (or placebo) was diluted in 500 ml of 10% Levulose, and administered intravenously; 1000 gamma of B12 vitamin were added to each bottle. Patients in the 2-MPG group received 2.5 gms of the drug daily; the treatment lasted for 30 days. The following parameters were checked in all patients on admission, and repeated at the end of treatment: Serum bilirubin, serum Cholesterol, A.P., BSP retention, Prothrombin time, S-GOT, S-GPT, Gamma-GT, Total serum Protein, serum electrophoresis, Immunoglobulins. Patients given 2-MPG showed significant decreases of serum transaminases, and improvement of BSP retention.