Efficient gene delivery to the cone-enriched pig retina by dual AAV vectors.

Gene therapy with adeno-associated viral (AAV) vectors is limited by AAV cargo capacity that prevents their application to the inherited retinal diseases (IRDs), such as Stargardt disease (STGD) or Usher syndrome type IB (USH1B), which are due to mutations in genes larger than 5 kb. Trans-splicing or hybrid dual AAV vectors have been successfully exploited to reconstitute large gene expression in the mouse retina. Here, we tested them in the large cone-enriched pig retina that closely mimics the human retina. We found that dual AAV trans-splicing and hybrid vectors transduce pig photoreceptors, the major cell targets for treatment of IRDs, to levels that were about two- to threefold lower than those obtained with a single AAV vector of normal size. This efficiency is significantly higher than that in mice, and is potentially due to the high levels of dual AAV co-transduction we observe in pigs. We also show that subretinal delivery in pigs of dual AAV trans-splicing and hybrid vectors successfully reconstitute, albeit at variable levels, the expression of the large genes ABCA4 and MYO7A mutated in STGD and USH1B, respectively. Our data support the potential of dual AAV vectors for large gene reconstitution in the cone-enriched pig retina that is a relevant preclinical model.

Numerical simulation of incompressible viscous flow in deforming domains.

We present a second-order accurate finite difference method for numerical solution of the incompressible Navier-Stokes equations in deforming domains. Our approach is a generalization of the Bell-Colella-Glaz predictor-corrector method for incompressible flow. In order to treat the time-dependence and inhomogeneities in the incompressibility constraint introduced by presence of deforming boundaries, we introduce a nontrivial splitting of the velocity field into vortical and potential components to eliminate the inhomogeneous terms in the constraint and a generalization of the Bell-Colella-Glaz algorithm to treat time-dependent constraints. The method is second-order accurate in space and time, has a time step constraint determined by the advective Colella-Friedrichs-Lewy condition, and requires the solution of well behaved linear systems amenable to the use of fast iterative methods. We demonstrate the method on the specific example of viscous incompressible flow in an axisymmetric deforming tube.

Treatment of obese patients with obstructive sleep apnea syndrome (OSAS): effect of weight loss and interference of otorhinolaryngoiatric pathology.

The role of weight loss in the therapy of obstructive sleep apnea syndrome (OSAS) was investigated in 23 affected patients with various degrees of obesity (body mass index range 26.6-61.0) free of cranio-facial malformations. Weight loss resulted 18.5 +/- 14.7 (s.d.) kg and was significantly correlated with baseline BMI value (r = 0.94; P less than 0.0001). Weight loss significantly reduced the number of apneas + hypopneas per hour of sleep ((A + H)I) from 66.5 +/- 23.0 to 33.0 +/- 26.2 (P less than 0.0001) and improved the mean of oxygen desaturation peaks during apneas (mSaO2) from 81.9 +/- 6.9 to 87.6 +/- 3.9; P less than 0.001). A significant correlation was found between weight loss and changes in the (A + H)I (r = -0.55; P less than 0.01) and the mSaO2 (r = 0.46; P less than 0.05). The (A + H)I significantly improved in both patients who lost more than 10 kg (basal BMI: 42.3 +/- 10.0) and in those who lost less than 10 kg (basal BMI: 30.2 +/- 2.3), whereas the mSaO2 improved only in the former. Obese patients with moderate to heavy ORL pathological findings had worse pretreatment and final OSAS parameters than those with absent or mild ORL lesions. However, both groups showed a significant, although quantitatively different, improvement of the (A + H)I and mSaO2 after weight loss. Compared to those who were cured or improved after the treatment, patients who failed to obtain significant effects on OSAS clinical presentation also had a significantly higher prevalence of ORL pathology. It is concluded that: (1) weight loss improves parameters and clinical presentation of OSAS in the majority of affected obese patients; (2) a relationship exists between the entity of weight loss and that of improvement of the syndrome; (3) weight loss must be encouraged even in patients with mild to moderate overweight; (4) the presence of ORL pathology may represent a confusing factor in the interpretation of the results obtained after weight loss.

Benfluorex action on metabolic control and insulin sensitivity in type 2 non-insulin dependent diabetics.

In this study, 16 overweight or obese NIDDM patients with a long period of stable weight and dietary surveillance were treated with 150 mg t.i.d. of Benfluorex per os for 3 months. A significant improvement occurred in the fasting and post-meal glucose levels and in the HbA1C values, regardless of weight changes that occurred throughout the study. No significant changes were found in the fasting or meal-stimulated insulin (IRI) levels and in the glucose:IRI molar ratios. On the contrary, there were no significant variations in C-peptide levels while the glucose:CPR ratio appeared to decrease while on Benfluorex. In basal conditions, 11 patients presented insulin insensitivity (as measured by the glucose-insulin-somatostatin technique) which was unaffected by the pharmacological treatment. Benfluorex may therefore ameliorate metabolic control in overweight or obese NIDDM patients, but our data do not clarify whether its effects are mediated by an improvement in the action of insulin in peripheral tissues.

Diabetic autonomic neuropathy and impaired human pancreatic polypeptide secretion in response to food.

In normal subjects, the early human pancreatic polypeptide (hPP) increase induced by food is mainly dependent on vagal activity. Parasympathetic function and plasma hPP response to a standard mixed meal were evaluated in 10 long term insulin-dependent (type I) diabetic patients (group A), 6 age-matched newly diagnosed type I diabetic patients (group B), and 8 normal subjects. The indices of vagal function (beat to beat heart rate variation during deep breathing and the Valsalva maneuver) were uniformly altered in group A, while they were in the normal range in group B, thus excluding in these latter patients the presence of vagal damage. Plasma hPP in response to standard mixed meal was measured at 5, 15, 30, 60, and 120 min. Fasting plasma hPP concentrations (determined by RIA) in groups A and B (mean +/- SEM, 113 +/- 21 and 83 +/- 21 pg/ml, respectively) did not significantly differ from normal (59 +/- 12 pg/ml). In group A, the initial meal-induced hPP increase was significantly lower than normal (5 min, 139 +/- 12; 15 min, 173 +/- 24; 30 min, 137 +/- 17 pg/ml; P less than 0.01 vs. 5 min, 412 +/- 76; 15 min, 446 +/- 57; 30 min, 325 +/- 56 pg/ml). All group B patients had a marked early increase in the peptide, similar to that in the normal subjects. These results suggest that diabetic autonomic neuropathy is associated with dysfunction of hPP secretion, and the evaluation of hPP in response to SMM may be considered a sensitive and nonstressful method for the assessment of parasympathetic impairment in diabetes.