Adenoviral vectors for transient gene expression in human primitive hematopoietic cells: applications and prospects

The proliferation and differentiation of primitive hematopoietic cells is tightly controlled by a number of signaling pathways. Transient blockage or enhancement of these signaling pathways may provide a new approach to manipulate the proliferation and differentiation of primitive hematopoietic cells. Adenoviral vectors have in recent years emerged as powerful tools for transient gene expression in human primitive hematopoietic cells. Important advantageous properties of adenoviral vectors include: feasible production of high-titer vector preparations, high efficiency in transducing both quiescent and actively dividing cells, high levels of transient gene expression, and a lack of mutagenic properties associated with integrating vectors. Progress in adenoviral fiber retargeting was recently demonstrated to enable high gene transfer efficiency into nondividing human CD34(+) cells and nonobese diabetic/severe combined immunodeficient mouse bone marrow repopulating cells (SRCs), via the ubiquitously expressed CD46 as a cellular receptor. Importantly, fiber-retargeted adenoviral vectors can be engineered to report gene expression in single living CD34(+) cells, thereby facilitating the isolation and characterization of SRCs and its downstream progenitors based on intrinsic signaling pathways. This review focuses on the current progress and the potential future applications of adenoviral gene transfer into human primitive hematopoietic cells and leukemic cells.     

Long-term treatment with recombinant insulin-like growth factor (IGF)-I in children with severe IGF-I deficiency due to growth hormone insensitivity

CONTEXT: Children with severe IGF-I deficiency due to congenital or acquired defects in GH action have short stature that cannot be remedied by GH treatment. OBJECTIVES: The objective of the study was to examine the long-term efficacy and safety of recombinant human IGF-I (rhIGF-I) therapy for short children with severe IGF-I deficiency. DESIGN: Seventy-six children with IGF-I deficiency due to GH insensitivity were treated with rhIGF-I for up to 12 yr under a predominantly open-label design. SETTING: The study was conducted at general clinical research centers and with collaborating endocrinologists. SUBJECTS: Entry criteria included: age older than 2 yr, sd scores for height and circulating IGF-I concentration less than -2 for age and sex, and evidence of resistance to GH. INTERVENTION: rhIGF-I was administered sc in doses between 60 and 120 microg/kg twice daily. MAIN OUTCOME MEASURES: Height velocity, skeletal maturation, and adverse events were measured. RESULTS: Height velocity increased from 2.8 cm/yr on average at baseline to 8.0 cm/yr during the first year of treatment (P < 0.0001) and was dependent on the dose administered. Height velocities were lower during subsequent years but remained above baseline for up to 8 yr. The most common adverse event was hypoglycemia, which was observed both before and during therapy. It was reported by 49% of treated subjects. The next most common adverse events were injection site lipohypertrophy (32%) and tonsillar/adenoidal hypertrophy (22%). CONCLUSIONS: Treatment with rhIGF-I stimulates linear growth in children with severe IGF-I deficiency due to GH insensitivity. Adverse events are common but are rarely of sufficient severity to interrupt or modify treatment.     

ADHD-like symptoms and attachment in internationally adopted children

Internationally adopted children seem to be more likely to show ADHD-like symptoms than non-adopted children. The aims of this study were to explore the existence of ADHD-like symptoms and/or diagnosis in a sample of internationally adopted children depending on their country of origin and to describe the links that may exist between the display of these symptoms and observed narrative-based attachment patterns. A Catalan sample of 58 adopted children aged 7-8 (24 from Eastern Europe, 23 from China, and 11 from Ethiopia) was assessed with the Behavioral Assessment System for Children to identify ADHD-like symptoms, and the Friends and Family Interview to identify children's' attachment patterns. Results indicated that children adopted from Eastern Europe showed a trend toward more hyperactivity and significantly more attention problems than girls adopted from China. Children with a secure attachment showed significantly less attention problems and a trend toward less hyperactivity. More studies focusing on the etiology and treatment of these symptoms in adopted children are needed.     

Evolution of French Bordetella pertussis and Bordetella parapertussis isolates: increase of Bordetellae not expressing pertactin

Clin Microbiol Infect 2012; 18: E340-E346 ABSTRACT: Bordetella pertussis and Bordetella parapertussis are closely related bacterial agents of whooping cough. Whole-cell pertussis (wP) vaccine was introduced in France in 1959. Acellular pertussis (aP) vaccine was introduced in 1998 as an adolescent booster and was rapidly generalized to the whole population, changing herd immunity by specifically targeting the virulence of the bacteria. We performed a temporal analysis of all French B.?pertussis and B.?parapertussis isolates collected since 2000 under aP vaccine pressure, using pulsed-field gel electrophoresis (PFGE), genotyping and detection of expression of virulence factors. Particular isolates were selected according to their different phenotype and PFGE type and their characteristics were analysed using the murine model of respiratory infection and in vitro cell cytotoxic assay. Since the introduction of the aP vaccines there has been a steady increase in the number of B.?pertussis and B.?parapertussis isolates collected that are lacking expression of pertactin. These isolates seem to be as virulent as those expressing all virulence factors according to animal and cellular models of infection. Whereas wP vaccine-induced immunity led to a monomorphic population of B.?pertussis, aP vaccine-induced immunity enabled the number of circulating B.?pertussis and B.?parapertussis isolates not expressing virulence factors to increase, sustaining our previous hypothesis.     

Mechanisms of Exercise-Induced Pulmonary Hypertension in Patients With Cardiac Septal Defects

The objective of this study was to investigate mechanisms of exercise-induced pulmonary hypertension in patients with congenital cardiac septal defects. This was a randomized, placebo controlled, crossover drug trial in a single national pediatric cardiology centre that performs congenital cardiac defect surgery. There were 14 patients with cardiac septal defects and known exercise-induced pulmonary hypertension. The intervention consisted of 50 mg oral sildenafil versus placebo. Measurements included supine bicycle exercise echocardiography and oxygen uptake. The outcome measure was right-ventricular systolic pressure as estimated by Doppler tracings of tricuspid regurgitant jet as well as systolic and diastolic longitudinal myocardial velocities by color tissue Doppler echocardiography. Sildenafil did not change exercise right-ventricular systolic pressure during exercise; however, decreased systemic systolic pressure was seen. Enhanced biventricular longitudinal function with sildenafil compared with placebo was indicated by greater tissue Doppler velocities and displacement measurements during exercise. Finally, a less steep increase of right-ventricular pressure during exercise was associated with greater left-ventricular diastolic myocardial tissue Doppler velocity. Exercise-induced pulmonary hypertension in cardiac septal defects does not seem to have a pulmonary vasoconstrictive component, but it may be related to left-ventricular filling pressure. Furthermore, sildenafil improved biventricular systolic performance in this patient group, possibly related to decreased systemic afterload.     

Effect of insulin treatment on plasma oxidized LDL/LDL-cholesterol ratio in type 2 diabetic patients

OBJECTIVE: In type 2 diabetes mellitus, oxidized LDL/LDL-Cholesterol ratio, an accurate estimation of in vivo LDL oxidation, has been reported elevated and associated with macrovascular disease. Because insulin therapy induces significant modification of lipid metabolism, in type 2 diabetes, we evaluated the effect of insulin treatment on oxidized LDL/LDL-C ratio in type 2 diabetic patients and analyzed the results in comparison with the modifications induced by insulin on glycaemia, plasma lipids and LDL receptors. RESEARCH DESIGN AND METHODS: Plasma oxidized LDL concentrations were measured by sandwich ELISA in 21 type 2 diabetic patients before and 3 months after the introduction of insulin therapy, and in 27 age-matched controls. RESULTS: Type 2 diabetic patients had, compared to controls, significantly increased oxidized LDL/LDL-C ratio (P<0.0001). Three months after insulin treatment, oxidized LDL/LDL-C ratio was significantly reduced (21.1+/-4.7 vs. 24.0+/-5.8 U/mmol, P<0.01). This reduction was strongly associated, in multivariate analysis, with reduction of LDL(TG/cholesterol ratio) (P=0.008), and to a lesser extent with the decrease of LDL fructosamine (P=0.034), but not with the increase of the number of LDL receptors. CONCLUSIONS: In the present study we demonstrate for the first time a lowering effect of insulin therapy on oxidized LDL/LDL-C ratio in type 2 diabetic patients. This decrease is mainly associated with the reduction of LDL TG-enrichment, and to a lesser extent with the decrease of LDL glycation, but not with the insulin-induced increase in number of LDL receptors.     

Substrate oxidation during exercise: type 2 diabetes is associated with a decrease in lipid oxidation and an earlier shift towards carbohydrate utilization

OBJECTIVES: Exercise is a recommended treatment for type 2 diabetes but the actual pattern of metabolic adaptation to exercise in this disease is poorly known and not taken in account in the protocols used. Metabolic defects involved in the pathways of substrate oxidation were described in type 2 diabetes. We hypothesized that type 2 diabetes, regardless of age, gender, training status and weight, could influence by its own the balance of substrates at exercise. METHODS: 30 sedentary type 2 diabetic subjects and 38 sedentary matched control subjects were recruited. We used exercise calorimetry to determine lipid and carbohydrate oxidation rates. We calculated two parameters quantifying the balance of substrates induced by increasing exercise intensity: the maximal lipid oxidation point (PLipoxMax) and the Crossover point (COP), intensity from which the part of carbohydrate utilization providing energy becomes predominant on lipid oxidation. RESULTS: Lipid oxidation was lower in the diabetic group, independent of exercise intensity. PLipoxMax and COP were lower in the diabetic group [PLipoxMax=25.3+/-1.4% vs. 36.6+/-1.7% %Wmax (P<0.0001)] - COP =24.2+/-2.2% vs. 38.8+/-1.9% %Wmax (P<0.0001). CONCLUSIONS: Type 2 diabetes is associated with a decrease in lipid oxidation at exercise and a shift towards a predominance of carbohydrate oxidation for exercise intensities lower than in control subjects. Taking into account these alterations could provide a basis for personalizing training intensity.     

Is plasma viscosity a predictor of overtraining in athletes?

There is a lack of consensus about the biological diagnosis of the overtraining syndrome (OTS). Recently, efforts have been made to standardize its clinical diagnosis (e.g., standardized questionnaires like that of the French consensus group on overtraining of the Société Fran?aise de Médecine du Sport-SFMS). We previously reported that the early signs of overtraining (= "overreaching") in elite sportsmen are associated with a hemorheologic pattern (raised hematocrit and plasma viscosity etap) that suggests some degree of reversal of the "autohemodilution" which characterizes fitness, and that the feeling of heavy legs in overtrained athletes is related to higher etap and higher red cell aggregation. We thus investigated on a sample of 48 athletes (age 24 +/- 1 yr), referred for possible diagnosis of overtraining to what extent plasma viscosity is a predictor of OTS. From those 48 athletes 10 had a value of etap in the highest quartile (etap > 1.44 pPa.s) and 8 of them had a diagnosis of overreaching, while in the 38 whose etap was < 1.44 mPa.s there were 20 cases of overreachings. Overt cases of OTS were found in 1 subject of the highest quintile and two in the lowest. Thus the predictive value of etap for early stages (overreaching) or chronicized stages (overtraining syndrome) is as follows: (a) prediction of overreaching: sensitivity 28.57%; specificity 90%; positive predictive value 80%; negative predictive value 47.37%; (b) prediction of chronicized overtraining: sensitivity 2.70%; specificity 18.18%; positive predictive value; 10.00%; negative predictive value 5.26%. These results show that etap is a rather specific, although poorly sensitive predictor of overreaching but has no interest in the diagnosis of the overtraining syndrome itself.