Total Endovascular Aortic Replacement in Post-Dissecting Thoraco-Abdominal Aortic Aneurysm with A New Inner Branched Device.

To describe a new inner-branched device used to treat two cases of chronic post-dissection aortic thoraco-abdominal aneurysms (PD-TAAAs) after ascending aortic surgery. A 67-year-old male who had undergone an ascending aorta and arch surgical replacement and a 70-year-old male with a previous Bentall procedure for acute type A aortic dissection were admitted at our department with a PD-TAAA diagnosis. Both patients were defined unfit for open surgery by a multidisciplinary team and a totally percutaneous endovascular repair was planned. A prophylactic cerebro-spinal fluid drainage was applied and at least one hypogastric artery was targeted for salvage in order to reduce the risk of spinal cord ischemia. A new inner branch device by Jotec® (GmbH/ Criolife; Hechingen, Germany/Kennesaw, Georgia) was implanted. A TEVAR and a standard EVAR completed the procedures and a double barrel technique was performed in order to achieve the preservation of the selected hypogastric artery. In both patients the complete technical success was achieved. The postoperative period was uneventful and the patients were discharged on the 6th and 7th postoperative day, respectively. The triple-phase angio-CT performed at 6 months showed the complete false lumen exclusion and the patency of the endografts and of the target visceral vessels. The total endovascular treatment of PD-TAAAs is a fascinating technique with encouraging results in experienced centers. Inner branched devices may expand the field of application of this new technology. More data are required to evaluate mid- and long-term results.

A Mechanized Pediatric Elbow Joint Powered by a De-Based Artificial Skeletal Muscle.

To increase the acceptability of exoskeletons, there is growing attention toward finding an alternative soft actuator that can safely perform at close vicinity of the human body. In this study, we investigated the capability of the dielectric elastomer actuators (DEAs), for muscle-like actuation of rehabilitation robots. First, an artificial skeletal muscle was configured using commercially available stacked DEAs arranged in a 3x4 array of three parallel fibers consisting of four DEAs connected in series. The shortening and force generation capabilities of this artificial muscle were then measured. An alternate 3x5 version of this muscle was mounted on the forearm of an upper extremity phantom model to actuate its elbow joint. The actuation capability of this muscle was then tested under various tensile loads, 1 N to 4 N, placed at the center of mass of the forearm+hand of the phantom model. The active range of motion and angular velocity of the phantom model's tip of the hand were measured using a motion capture system. The 3×4 artificial muscle produced 30.47 N of force and 5.3 mm of maximum shortening. The 3x5 artificial muscle was capable of actuating the elbow flexion 19.5º with 16.2 º/s angular velocity in the sagittal plane, under a 1 N tensile load. The active range of motion was substantially reduced as the tensile loads increased, which limits the capability of these muscles in the current upper extremity exoskeleton design.

Engineering plasmonic metal colloids through composition and structural design.

The optical properties of metal nanomaterials are determined by a set of parameters that include composition, particle size and shape, overall architecture, and local environment. This Tutorial Review examines the influence of each of these factors on the localized surface plasmon resonance of colloidal metal nanoparticles. This examination is paralleled with a discussion of the advances which have enabled the synthesis of structurally defined metal nanomaterials, as these samples serve as the best platforms for elucidating the fundamental properties of plasmonic colloids. Based on the analysis of such samples, five guidelines are presented to aid the rational design and synthesis of new metal nanostructures for advanced applications in nanomedicine, energy, chemical sensing, and colloidal plasmonics in general.

Effectiveness of a propolis and zinc solution in preventing acute otitis media in children with a history of recurrent acute otitis media.

Recurrent acute otitis media (rAOM) is frequently encountered in infants and children and the lack of any definitive treatment has led parents and physicians to try complementary and alternative therapies. We evaluated the efficacy of a propolis and zinc suspension in preventing AOM in 122 children aged 1-5 years with a documented history of rAOM, who were prospectively, blindly, randomized 1:1 to receive the suspension plus elimination of environmental risk factors or elimination of environmental risk factors only. AOM- and respiratory-related morbidity were assessed at study entry and every four weeks. In the 3-month treatment period AOM was diagnosed in 31 (50.8%) children given the propolis and zinc suspension and in 43 (70.5%) controls (p=0.04). The mean number of episodes of AOM per child/month was 0.23+/-0.26 in the propolis and zinc group and 0.34+/-0.29 in controls (reduction 32.0%, p=0.03). The administration of a propolis and zinc suspension to children with a history of rAOM can significantly reduce the risk of new AOM episodes and AOM-related antibiotic courses, with no problem of safety or tolerability, and with a very good degree of parental satisfaction. No effect can be expected on respiratory infections other than AOM.

Structural determinants of CCR5 recognition and HIV-1 blockade in RANTES.

Certain chemokines act as natural antagonists of human immunodeficiency virus (HIV) by blocking key viral coreceptors, such as CCR5 and CXCR4, on the surface of susceptible cells. Elucidating the structural determinants of the receptor-binding and HIV-inhibitory functions of these chemokines is essential for the rational design of derivative molecules of therapeutic value. Here, we identify the structural determinants of CCR5 recognition and antiviral activity of the CC chemokine RANTES, showing that critical residues form a solvent-exposed hydrophobic patch on the surface of the molecule. Moreover, we demonstrate that the biological function is critically dependent on dimerization, resulting in the exposure of a large ( approximately 180 A2), continuous hydrophobic surface. Relevant to the development of novel therapeutic approaches, we designed a retroinverted RANTES peptide mimetic that maintained both HIV- and chemotaxis-antagonistic functions.

HIV-1-specific immunity in persistently seronegative individuals at high risk for HIV infection.

A growing number of reports indicates that certain groups of individuals who almost certainly have been exposed to human immunodeficiency virus (HIV), yet continue to exhibit no signs or symptoms of infection, often have subtle evidence of specific immunity. We studied such a high-risk (HR) cohort of persistently seronegative individuals with histories of long-term sexual exposure to an HIV-infected partner to look for evidence of both humoral and cellular immunity that might have been induced by exposure to the virus. Twenty-three heterosexual and four homosexual monogamous couples with discordant HIV status were included in the study. Twelve of the HR partners were studied for in vitro stimulation of peripheral blood mononuclear cells (PBMC) by HIV envelope-derived peptides. All 12 responded overwhelmingly to a peptide containing the fifth conserved region of gp120. By generating and cloning T cell lines specific for this peptide, we concluded that in these individuals the T cell response to the envelope is mainly focused on the carboxy-terminus region of gp120 and is characterized by an oligoclonal expansion of CD4+ T cells expressing the same TCR Eighteen HR partners and 37 HIV-1 seropositive subjects were tested for the presence of anti-CD4 antibodies (anti-CD4 Abs) using a recombinant CD4-based enzyme-linked immunosorbent assay (ELISA). Anti-CD4 Abs were detected in eight of the HR partners (six confirmed by Western blot) and in nine of the HIV-1 seropositive subjects (eight confirmed by Western blot). Results from binding competition assays with a panel of monoclonal anti-CD4 Abs suggested that the anti-CD4 Abs detected in the HR partners are directed toward epitopes that are induced by gp120 binding. Twenty-seven of the HR partners were tested for the presence of antibodies that cross-react with HLA class I and gp120 (anti-HLA Abs). Anti-HLA Abs were detected in 16 of the HR partner sera and in 4/94 sera from a control population of normal healthy blood donors. Taken together, the results suggest that in some individuals with a history of long-term exposure to HIV, specific immunity may develop in the absence of overt infection. The common trigger for these responses is gp120.

Effect of ceruletide on rest pain in patients with arterial insufficiency of the lower extremity.

The effect of ceruletide (CRL), a synthetic decapeptide analogue of cholecystokinin, on rest pain and arterial blood flow was evaluated in 8 patients with advanced, occlusive atherosclerosis of the lower extremities. CRL 1, 2, or 4 ng kg-1 or placebo were infused intravenously in random order, and in a double-blind fashion. Pain relief, assessed by a scoring system, was significantly better (p less than 0.01) following the 2 and 4 ng kg-1 doses of CRL (2.71 and 2.66, respectively) than following placebo (0.75). Arterial blood flow was not affected by either CRL in any dose or by placebo. Pretreatment with naloxone, a pure opioid antagonist, abolished the analgesic effect of CRL. Following the 2 ng dose of CRL, beta-endorphin levels were significantly elevated from a basal value of 125 +/- 15 pg/ml to 191 +/- 35 pg/ml 5 h after CRL administration (p less than 0.05). Circulating levels of ACTH, prolactin and GH were not affected by CRL. It is concluded that CRL was effective in relieving ischaemic rest pain, and that the mechanism was related to the release of endogenous opioids.