Albumin nanoparticles improved the stability, nuclear accumulation and anticytomegaloviral activity of a phosphodiester oligonucleotide.

The goal of this study was to evaluate the potential of albumin nanoparticles as a delivery system for antisense oligonucleotides. Nanoparticles were prepared by a coacervation process and cross-linkage with glutaraldehyde. Phosphodiester (PO) and phosphorotioate (PS) oligonucleotides were either adsorbed on the surface of nanoparticles (PO-NPA and PS-NPA) or incorporated in the nanoparticle matrix (PO-NPB and PS-NPB). When PO-loaded nanoparticles were incubated with phosphodiesterase, only NPB was able to keep the oligonucleotide hybridization capability for at least 60 min. The antiviral activity was evaluated in MRC-5 fibroblasts infected with human cytomegalovirus at a MOI of 0.0035. Both PO nanoparticle formulations significantly increased the antiviral activity of free PO (P<0.001) and NPB showed slightly higher efficacies than NPA (P<0.05). On the other hand, PS exhibited significant higher activity than free PO (P<0.001), however, no significant differences were found between PS-nanoparticle and PO-nanoparticle formulations. These findings were well correlated with the intracellular distribution observed for fluorescent oligonucleotide-loaded albumin nanoparticles. Even these carriers delayed and decreased the uptake of PO by MRC-5 cells, they finally induced a diffused cytoplasmic distribution and major nuclear accumulation. In summary, albumin nanoparticles partially protected a PO against enzymatic degradation and improved their presence in the nucleus and thus, increased its efficiency.     

In-vitro model for the ultrastructural study of the formation of thrombi in human platelets.

Platelets are cell fragments with dynamic properties involved in clot formation after tissue damage. Platelet activation causes a change in shape, secretion of intracellular granules and aggregation with each other through the cytoskeleton components and biochemical changes. Platelet adhesion, considered as the major event in haemostasis, has been studied in several in-vitro and in-vivo models to evaluate the feasible thrombogenicity of some materials, the dynamics of specific receptors, as well as the effect of different buffers and inhibitors in this process. In spite of the numerous reports about platelet activation, to date there is no information available about the fine structure of the platelet-platelet and platelet-substrate interactions. In the present report we describe an in-vitro system that allows the visualization of these interactions: platelets are adhered to an inert substrate, and interactions with suspended platelets as a process to initiate the formation of thrombi was followed by ultramicrotomy and transmission electron microscopy.     

Brachial endothelial function in subjects with familial combined hyperlipidemia and its relationships to carotid artery intima-media thickness.

AIM: The aim of this study was to quantify the flow-mediated dilatation (FMD) of brachial artery in asymptomatic members of families with familial combined hyperlipidemia (FCH) and to determine the relation between FMD and risk factors accompanying FCH. We also investigated the association between FMD and the intima-media thickness (IMT) of the common carotid artery. METHODS: Eighty-two members of 29 FCH families were divided into two groups: probands and hyperlipidemic first-degree relatives (HL) (n=47) and normolipidemic first-degree relatives (NL) (n=35). The control (C) groups, C-HL (n=20) and C-NL (n=20), consisted of sex- and age-matched healthy individuals. FMD was assessed in the brachial artery by measuring the change in brachial artery diameter in response to reactive hyperemia. RESULTS: Both hyperlipidemic subjects and their NL had significantly lower FMD (3.4+/-3% vs 6.3+/-2.8%, P<0.001, 5.2+/-2.3% vs 7.8+/-2.8%, P<0.01, respectively) compared to controls. In multivariate backward stepwise regression analysis, FMD in members of FCH families was independently associated with sex (P<0.001), age (P<0.01), C-peptide (P<0.05) and borderline with glycemia (P=0.052). FMD correlated inversely with IMT in all subjects of FCH families and in hyperlipidemic members. In multivariate backward stepwise regression analysis this relation remained independent (P<0.001, P<0.01, respectively). CONCLUSIONS: Members of FCH families showed impaired FMD, which was independently associated with markers of insulin resistance. FMD and IMT were independently associated in hyperlipidemic, but not in normolipidemic members of FCH families.     

Modulation of arterial stiffness with intensive competitive training.

BACKGROUND: Aerobic exercise training has been associated with beneficial effects on the cardiovascular system, improving arterial compliance, possibly related to a positive impact on the endothelium. The effects of competitive aerobic exercise are not so well documented. This prompted us to evaluate the possible modulation of arterial properties in a group of athletes and their response to the aging process. METHODS: 423 healthy males were enrolled in a cross-sectional study, 212 of whom were competitive athletes and 211 were controls. All underwent carotid-femoral pulse wave velocity (PWV) evaluation, and casual blood pressure and other relevant anthropometric data were evaluated. RESULTS: To control the effects of age, each group was divided into two subgroups with an age cut-point of 20 years. PWV was 6.3 +/- 0.9 m/s (athletes) vs. 7.0 +/- 1.0 m/s (controls) for ages <20 years, and 7.6 +/- 1.2 m/s (athletes) vs. 8.1 +/- 0.9 m/s (controls) for ages >20 years, with statistically significant differences in both comparisons. A linear regression model with logarithmic tendency analysis with age as the independent determinant of PWV revealed a different progression of age-related deterioration of aortic compliance between the two groups (athletes and controls). CONCLUSIONS: Our data documented better compliance indices in competition athletes compared with controls, which may reflect optimization of endothelial function. This improvement was age-dependent, being less pronounced as the athletes grow older, which could be due partially to sustained stretching effects on the arterial walls in long-term competitors.     

Estimation of salt intake by urinary sodium excretion in a Portuguese adult population and its relationship to arterial stiffness.

BACKGROUND: Portugal has one of the highest mortality rates from stroke, a high prevalence of hypertension and probably a high salt intake level. AIM: To evaluate Portuguese salt intake levels and their relationship to blood pressure and arterial stiffness in a sample of four different adult populations living in northern Portugal. METHODS: A cross-sectional study evaluating 24-hour urinary excretion of sodium (24 h UNa+), potassium and creatinine, blood pressure (BP), and pulse wave velocity (PWV) as an index of aortic stiffness in adult populations of sustained hypertensives (HT), relatives of patients with previous stroke (Fam), university students (US) and factory workers (FW), in the context of their usual dietary habits. RESULTS: We evaluated a total of 426 subjects, mean age 50 +/- 22 years, 56% female, BMI 27.9+/-5.1, BP 159/92 mmHg, PWV 10.4+/-2.2 m/s, who showed mean 24h UNa+ of 202 +/- 64 mmol/d, corresponding to a daily salt intake of 12.3 g (ranging from 5.2 to 24.8). The four groups were: HT: n = 245, 49 +/- 18 years, 92% of those selected, 69% treated, BP 163/94 mmHg, PWV 11.9 m/s, 24 h UNa+ 212 mmol/d, i.e. 12.4 g/d of salt); Fam: n = 38, 64 +/- 20 years, 57 % of those selected, BP 144/88 mmHg, PWV 10.5 m/s, 24 h UNa+ 194 mmol/d, i.e. 11.1 g/d of salt; US: n = 82, 22 +/- 3 years, 57% of those selected, BP 124/77 mmHg, PWV 8.7 m/s, 24h UNa+ 199 mmol/d, i.e. 11.3 g/d of salt; FW: n = 61, 39 9 years, 47% of those selected, BP 129/79 mmHg, PWV 9.5 m/s, 24 h UNa+ 221 mmol/d, i.e. 12.9 g/d of salt. The ratio of urinary sodium/potassium excretion (1.9 (0.4) was significantly higher in HT than the other three groups. In the 426 subjects, 24h UNa+ correlated significantly (p < 0.01) with systolic BP (r = 0.209) and with PWV (r=0.256) after adjustment for age and BP. Multivariate analysis showed that BP, age and 24h UNa+ correlated independently with PWV taken as a dependent variable. CONCLUSIONS: Four different Portuguese populations showed similarly high mean daily salt intake levels, almost double those recommended by the WHO. Overall, high urinary sodium excretion correlated consistently with high BP levels and appeared to be an independent determining factor of arterial stiffness. These findings suggest that Portugal in general has a high salt intake diet, and urgent measures are required to restrict salt consumption in order to prevent and treat hypertensive disease and to reduce overall cardiovascular risk and events.     

Online data visualization using the neural gas network.

A high-quality distance preserving output representation is provided to the neural gas (NG) network. The nonlinear mapping is determined concurrently along with the codebook vectors. The adaptation rule for codebook positions in the projection space minimizes a cost function that favors the trustworthy preservation of the local topology. The proposed visualization method, called OVI-NG, is an enhancement over curvilinear component analysis (CCA). The results show that the mapping quality obtained with OVI-NG outperforms the original CCA, in terms of the trustworthiness, continuity, topographic function and topology preservation measures.     

The use of endoprostheses (stents) in airway stenosis]

Six patients with obstruction of the trachea were treated with silicone rubber endothracheal stents implanted with flexible bronchoscope. In every case the stent caused significant clinical improvement of the ventilation. At the postintubation stenosis the stent can result a final recovery, at the malignant processes the implantation seems to be a new palliative method.