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.

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.

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.

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.

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.

Dual cut-off transient elastography to assess liver fibrosis in chronic hepatitis B: a cohort study with internal validation.

BACKGROUND: Transient elastography has gained popularity to stage liver fibrosis in chronic viral hepatitis, however, diagnostic cut-offs for severe fibrosis in chronic hepatitis B are poorly defined. AIM: To evaluate an algorithm with two distinct cut-offs for positive and negative prediction of significant fibrosis and cirrhosis in chronic hepatitis B patients. METHODS: Two cohorts of treatment-naïve patients with chronic hepatitis B (125 training and 92 validations) were consecutively and concurrently examined by percutaneous liver biopsy and transient elastography. Fibrosis was staged by Metavir (significant fibrosis = F ≥ 2; cirrhosis = F4) in ≥ 2 cm long liver tissue cores. RESULTS: A >13.1 kPa positive and a ≤ 9.4 kPa negative cut-off for cirrhosis had a >90% sensitivity and specificity, with an accuracy of 94%. The corresponding cut-offs for F ≥ 2 were >9.4 and ≤ 6.2 kPa, thus classifying 56% of patients with an overall accuracy of 90%. In the validation cohort, F4 and F ≥ 2 were predicted by the above transient elastography cut-offs with an overall accuracy >90%. In 165 patients with higher than upper limit of normal transaminase activity the dual cut-off algorithm of transient elastography was as accurate as in the 52 patients with normal alanine aminotransferase values in the prediction and exclusion of cirrhosis, only. CONCLUSIONS: A dual cut-off algorithm allowed for correctly classifying both significant fibrosis and cirrhosis in the majority of the patients with chronic hepatitis B, independent of alanine aminotransferase values, thus reducing the need for liver biopsy investigations.

Standardized crush injury of the mouse median nerve.

The employment of transgenic mouse models for peripheral nerve regeneration studies is continuously increasing. In this paper, we describe a standardized method for inducing a crush lesion in mouse median nerve using a non-serrated clamp exerting a crush compression force of 20.43 MPa for a duration of 30 s. Quantitative assessment of posttraumatic functional recovery by grasping test showed that recovery was very fast and mice returned to baseline performance already after 20 days only. Stereological analysis of nerve fibers distal to the crush lesion showed the presence of axons with a significantly smaller size and thinner myelin sheath in comparison to controls. This experimental nerve injury model is highly reproducible and the impact on animal well-being is minimal. Its employment can be particularly indicated for exploring the basic neurobiological mechanisms of peripheral nerve regeneration.

Calibration of the stereological estimation of the number of myelinated axons in the rat sciatic nerve: a multicenter study.

Several sources of variability can affect stereological estimates. Here we measured the impact of potential sources of variability on numerical stereological estimates of myelinated axons in the adult rat sciatic nerve. Besides biological variation, parameters tested included two variations of stereological methods (unbiased counting frame versus 2D-disector), two sampling schemes (few large versus frequent small sampling boxes), and workstations with varying degrees of sophistication. All estimates were validated against exhaustive counts of the same nerve cross sections to obtain calibrated true numbers of myelinated axons (gold standard). In addition, we quantified errors in particle identification by comparing light microscopic and electron microscopic images of selected consecutive sections. Biological variation was 15.6%. There was no significant difference between the two stereological approaches or workstations used, but sampling schemes with few large samples yielded larger differences (20.7+/-3.7% SEM) of estimates from true values, while frequent small samples showed significantly smaller differences (12.7+/-1.9% SEM). Particle identification was accurate in 94% of cases (range: 89-98%). The most common identification error was due to profiles of Schwann cell nuclei mimicking profiles of small myelinated nerve fibers. We recommend sampling frequent small rather than few large areas, and conclude that workstations with basic stereological equipment are sufficient to obtain accurate estimates. Electron microscopic verification showed that particle misidentification had a surprisingly variable and large impact of up to 11%, corresponding to 2/3 of the biological variation (15.6%). Thus, errors in particle identification require further attention, and we provide a simple nerve fiber recognition test to assist investigators with self-testing and training.

Functional and morphological assessment of a standardized crush injury of the rat median nerve.

The availability of effective experimental models for investigating nerve regeneration and designing new strategies for promoting this unique repair process is important. The aim of this study was to standardize a rat median nerve crush injury model using a non-serrated clamp exerting a compression force of 17.02 MPa for a duration of 30s. Results showed that functional recovery, evaluated by grasping test, was already detectable at day-12 and progressively increased until day-28 after which animal performance plateaued until the end of testing (day-42), reaching a range of 75-80% of pre-operative values. Morphological analysis on the median nerve segments, distal to the crush lesion, which were withdrawn at the end of the experiment showed that regenerated nerve fibers are significantly more numerous and densely packed; they are also smaller and have a thinner myelin sheath compared to controls. Together, these results provide a baseline characterization of the crush median nerve injury experimental model for its employment in the investigation of nerve regeneration research, especially when a reproducible regeneration process is required, such as for the study of biological mechanisms of peripheral nerve fiber regeneration or development of new therapeutic agents for promoting posttraumatic nerve repair.

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.

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.

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.

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.

Rapid detection of bluetongue virus in blood and organ samples using a capture enzyme-linked immunosorbent assay.

An antigen capture ELISA for bluetongue (BT) virus was developed using tissue culture supernatant to identify different BT virus (BTV) serotypes 1, 2, 4, 9 and 16, which have been incriminated in the current epidemic in the Mediterranean Basin. To obtain a positive result and after amplification in tissue culture, the minimum amount of infecting virus required was 100 TCID(50). Results from the antigen capture ELISA were compared with conventional methods for virus isolation and identification, such as virus amplification on embryonated chicken eggs (ECEs), followed by tissue culture and the direct immunofluorescence test. The sensitivity and specificity of the ELISA in infected tissue culture supernatant using homogenates of BTV-positive ovine and bovine organs and blood, without a previous step in ECEs, were 100%. The assay was also applied to homogenates of chicken embryo tissues, which had been infected with different BTV serotypes. This method enabled detection of the virus with 100% sensitivity and specificity rates, also using amplification in ECEs. Furthermore, among the various embryo tissues tested, liver was found to be the most suitable for use with ELISA. In experimentally infected ovine blood samples, the ELISA revealed the presence of the virus. Given the high sensitivity and specificity obtained with the BTV serotypes in this trial, the method should greatly facilitate BT diagnosis.

Use of the complement fixation and brucellin skin tests to identify cattle vaccinated with Brucella abortus strain RB51.

In the European Union, RB51 vaccine can be used only under strictly controlled conditions for the immunisation of cattle at risk of infection with Brucella abortus. A test is therefore necessary to distinguish vaccinated from unvaccinated animals. The complement fixation test with RB51 antigen (RB51-CFT), dot-blot and gamma-interferon used to identify vaccinated animals have been described, but sensitivity of the tests has been poor and positivity transient after calfhood vaccination. To avail of a rapid and accurate diagnostic tool, the authors produced, controlled and evaluated an experimental brucellin prepared from strain RB51 (RB51 brucellin). The potency of this brucellin was evaluated in guinea-pigs sensitised with RB51 and compared with a commercially available brucellin. Both allergens produced similar biological activity in guinea-pigs. The RB51 brucellin skin test was performed in 10 cattle 414 days after calfhood vaccination with RB51 when they were negative to the RB51-CFT. The skin test revealed 60% sensitivity (with a confidence interval of 95%, CI 30.8%-83.3%) and 100% specificity (CI 60.7%-100%). These findings limit the use of the skin test only for screening to detect RB51 vaccinated herds, not individual animals. Nevertheless, following intradermal inoculation of RB51 brucellin, a transient antibody increase to the RB51-CFT was observed, from day 9 to day 20 post inoculation with RB51 brucellin. This transient antibody increase, when evaluated in parallel with the RB51 brucellin skin test results, enables detection of individual vaccinated animals (sensitivity 100%; CI 76.2%-100%).

Late diagnosis in severe and mild intellectual disability in adulthood.

BACKGROUND: The diagnosis of intellectual disability (ID) is highly dependent on a comprehensive personal and family medical history, a complete physical examination and a careful developmental assessment of the patient. Our study intended to: (1) classify the aetiology of mild and severe ID in an adult population of 140 Italian subjects; (2) evaluate the frequency of associated medical conditions; (3) evaluate the age of diagnosis in both groups; and (4) underline the importance of aetiological diagnosis for adult ID patients also. METHODS: The study involved 140 consecutive adult Italian ID inpatients and outpatients neurologically investigated at the Neurological Institute C. Mondino of Pavia Service for Mental Retardation. A total of 80 patients had mild ID (MID group) (39 females, 41 males), mean age 34 years (range 19-61 years), mean IQ = 64 (range 51-75), and 60 had severe ID (SID group) (32 females, 28 males), mean age 30 years (range 19-69 years). They underwent a complete diagnostic work-up that comprised prenatal, perinatal and postnatal history, physical examinations, laboratory investigations, genetic survey and neuroradiological investigations to determine the aetiology of ID and to evaluate the presence of associated medical conditions. RESULTS: ID aetiology was classified as prenatal in 34% of the MID and 28% of the SID group. Perinatal and postnatal events were found in 6% of the MID and in 5% of the SID group. Associated medical conditions were found in 97 patients (47% MID and 26% SID). A genetic diagnosis was possible in 6% of patients above 20 years of age and in 5% of patients above 40 years. A diagnosis of cerebral dysgenesis was possible in 5% of patients above 20 years and 4% of patients above 40 years. CONCLUSIONS: A long interval between the diagnosis of ID and the aetiological definition can be observed in a significant percentage (24%) of our population, leading to unfortunate consequences of late diagnosis: late onset of a specific therapeutic program, genetic counselling that is frequently no more useful, and ineffective prenatal diagnosis, leading to the birth of other affected subjects (for familiar ID).

Efficacy and safety studies on an inactivated vaccine against bluetongue virus serotype 2.

An inactivated vaccine was produced from an Italian field isolate of bluetongue virus serotype 2 (BTV-2) with a titre of 10(7.8)TCID50/ml. The virus was purified through a molecular cut cassette membrane, inactivated with beta-propriolactone and emulsified with ISA 206 (Seppic) adjuvant. The vaccine was then tested for sterility, toxicity and safety in laboratory and target animals according to European Pharmacopoeia standards. Immunogenicity was assessed by inoculating subcutaneously 10 sheep and 10 goats each with 2 ml of the vaccine and 10 bovines each with 5 ml of the vaccine. A booster dose was inoculated after 14 days and no side-effects were reported following vaccination. Fourteen days after the booster dose, all vaccinated animals developed virus neutralising (VN) bluetongue (BT) antibody titres that on day 60 post vaccination ranged between 1/20 and 1/1 280. After one year, goats still had high VN antibody titres. Sheep were challenged 138 days after vaccination by subcutaneously inoculating 1 ml of 10(5.6)TCID50/ml of an Italian field isolate of BTV serotype 2; four unvaccinated animals were also inoculated and used as controls. Starting from day 6 post challenge, control animals developed a fever, with temperature ranging from 39.9 degrees C to 40.6 degrees C and lasting 48 h on average. BTV-2 was also isolated from the blood of control animals between days 4 and 20 post challenge. Conversely, neither fever nor viraemia were detected in the vaccinated animals that were challenged. A new trial with a larger number of animals, including all target species, has been planned and is in progress.

A prospective study of blood alpha-fetoprotein messenger RNA as a predictor of hepatocellular carcinoma in patients with cirrhosis.

Blood alpha-fetoprotein messenger RNA (AFP mRNA) is thought to be a marker of hepatocellular carcinoma (HCC). Its value as a predictor of HCC in patients at risk is not known. A series of 201 patients with compensated cirrhosis (114 men, mean age 58 years) underwent surveillance with semi-annual ultrasound and serum alpha-fetoprotein measurements. Total RNA was extracted from peripheral blood mononuclear cells collected at different intervals and AFP mRNA was retrotranscribed and amplified by nested polymerase chain reaction. Ten patients with HCC and 30 blood donors were used as controls. Three patients with HCC, 39 with cirrhosis under surveillance and four blood donors circulated AFP mRNA (30, 20 and 13%, NS). During 50 months of surveillance, 27 patients with cirrhosis developed HCC: the tumour was detected more often in patients with higher than normal baseline serum AFP (> or =7 IU/L) than in those with normal AFP levels (21%vs 9%, P = 0.02). The incidence of HCC was the same in patients with and without AFP mRNA at baseline (15%vs 14%). In 53 patients, AFP mRNA was re-tested after 6-25 months of surveillance. HCC developed in two of 11 (18%) who were initially AFP mRNA positive and later became negative, in none of those who were initially negative and later became positive and in two of 39 (5%) who remained persistently negative. In conclusion, blood AFP mRNA is not a sensitive predictor of HCC in patients with compensated cirrhosis.