Catalytic oxygen production mediated by smart capsules to modulate elastic turbulence under a laminar flow regime

Liquid flow in microchannels is completely laminar and uniaxial, with a very low Reynolds number regime and long mixing lengths. To increase fluid mixing and solubility of reactants, as well as to reduce reaction time, complex three-dimensional networks inducing chaotic advection have to be designed. Alternatively, turbulence in the liquid can be generated by active mixing methods (magnetic, acoustic waves, etc.) or adding small quantities of elastic materials to the working liquid. Here, polyelectrolyte multilayer capsules embodying a catalytic polyoxometalate complex have been suspended in an aqueous solution and used to create elastic turbulence and to propel fluids inside microchannels as an alternative to viscoelastic polymers. The overall effect is enhanced and controlled by feeding the polyoxometalate-modified capsules with hydrogen peroxide, H2O2, thus triggering an on-demand propulsion due to oxygen evolution resulting from H2O2 decomposition. The quantification of the process is done by analysing some structural parameters of motion such as speed, pressure, viscosity, and Reynolds and Weissenberg numbers, directly obtained from the capillary dynamics of the aqueous mixtures with different concentrations of H2O2. The increases in fluid speed as well as the capsule-induced turbulence effects are proportional to the H2O2 added and therefore dependent on the kinetics of H2O2 dismutation.

CHARGE syndrome: an overview on dental and maxillofacial features

OBJECTIVES

CHARGE is an acronym referring to the aspects of this rare syndromic condition. Patients with CHARGE association are today considered as subjects lacking in pathognomonic dental alterations. The present study is aimed at adding to the body of evidence of the cases reported in literature and the continuous clinical research which show a clinical picture which is strongly associated with patients afflicted by this syndrome.

PATIENTS AND METHODS

We report a case-series of 8 patients with CHARGE syndrome. The dental features associated with CHARGE syndrome are from case-reports, but without a congruity that can lead to a definition of the dental condition typical of the CHARGE phenotype.

CONCLUSIONS

The systemic problems affecting these patients are predominant in compromising their quality of life: this is the reason for a frequent lack of a diagnostics and interceptive phase, relative to oral diseases. We report new oral pathological conditions affecting CHARGE patients. Knowledge of these pathological conditions may induce dentists to carry out specific diagnoses of these patients, thus, avoiding the deterioration of oral conditions.

Severe pneumonia after intravesical BCG instillation in a patient with invasive bladder cancer: case report and literature review

We present here the case of a 66 year old man with a severe bilateral community acquired pneumonia secondary to dissemination after an intravesical instillation of bacilllus Calmette-Guerin (BCG). Diagnosis was based on positive polymerase chain reaction (PCR) for mycobacterium tuberculosis complex in bronchoalveolar lavage and on the finding on transbronchial biopsy of non necrotising granulomas histopathologically similar to the granulomas found in bladder biopsies. These findings were confirmed using a validated real time PCR assay demonstrating the presence of the BCG genome in transbronchial and bladder biopsies.

Anti-aggregating effect of the naturally occurring dipeptide carnosine on aβ1-42 fibril formation

Carnosine is an endogenous dipeptide abundant in the central nervous system, where by acting as intracellular pH buffering molecule, Zn/Cu ion chelator, antioxidant and anti-crosslinking agent, it exerts a well-recognized multi-protective homeostatic function for neuronal and non-neuronal cells. Carnosine seems to counteract proteotoxicity and protein accumulation in neurodegenerative conditions, such as Alzheimer's Disease (AD). However, its direct impact on the dynamics of AD-related fibril formation remains uninvestigated. We considered the effects of carnosine on the formation of fibrils/aggregates of the amyloidogenic peptide fragment Aβ1-42, a major hallmark of AD injury. Atomic force microscopy and thioflavin T assays showed inhibition of Aβ1-42 fibrillogenesis in vitro and differences in the aggregation state of Aβ1-42 small pre-fibrillar structures (monomers and small oligomers) in the presence of carnosine. in silico molecular docking supported the experimental data, calculating possible conformational carnosine/Aβ1-42 interactions. Overall, our results suggest an effective role of carnosine against Aβ1-42 aggregation.

Radiochemistry on chip: towards dose-on-demand synthesis of PET radiopharmaceuticals

We have developed an integrated microfluidic platform for producing 2-[(18)F]-fluoro-2-deoxy-D-glucose ((18)F-FDG) in continuous flow from a single bolus of radioactive isotope solution, with constant product yields achieved throughout the operation that were comparable to those reported for commercially available vessel-based synthesisers (40-80%). The system would allow researchers to obtain radiopharmaceuticals in a dose-on-demand setting within a few minutes. The flexible architecture of the platform, based on a modular design, can potentially be applied to the synthesis of other radiotracers that require a two-step synthetic approach, and may be adaptable to more complex synthetic routes by implementing additional modules. It can therefore be employed for standard synthesis protocols as well as for research and development of new radiopharmaceuticals.

Factors associated with access to antiviral treatment in a multicentre cross-sectional study of patients with chronic hepatitis B in Italy

A multicentre cross-sectional survey was performed to provide an accurate picture of patients with chronic hepatitis B (CHB) cared for by Italian Infectious Diseases Centers (IDCs). This analysis describes factors associated with access to the treatment of CHB in a country where barriers to treatment are not expected to exist because of comprehensive coverage under the National Health System (NHS). The study was performed in 74 IDCs. The analysis focused on 3305 patients with CHB of 3760 HBsAg-positive patients enrolled from March to September, 2008. To account for missing values, a Multiple Imputation method was used. Treatment was reported in 2091 (63.3%) patients. In the multivariate analysis, an increased chance of getting treatment was independently associated with 10 years increase of age at diagnosis (adjusted odds ratio [aOR] 1.2, 95% confidence interval [CI] 1.1-1.3, P < 0.001), HBeAg positivity (aOR 1.8, 95% CI 1.1-2.8, P < 0.001), cirrhosis (aOR 3.6, 95% CI 2-6.3, P = 0.012), HDV (aOR 1.6, 95% CI 1.02-2.5, P = 0.042) and HIV positivity (aOR 6.5, 95% CI 4-10.8, P < 0.001). Conversely, a decreased chance was associated with female gender (aOR 0.6, 95% CI 0.5-0.7, P < 0.001), immigration (aOR 0.6, 95% CI 0.5-0.9, P = 0.009), alcohol consumption (aOR 0.7, 95% CI 0.5-0.98, P = 0.04) and HCV positivity (aOR 0.5, 95% CI 0.3-0.8, P = 0.005). Our study shows that Italian IDCs treat a high percentage of patients with CHB. Nevertheless, disparities exist which are not related to the severity of disease limiting access to antiviral therapy of CHB, even in a country with a universal healthcare system.

Imaging tumors of the patella

BACKGROUND

Patellar tumors are rare; only a few series have been described in the literature and radiographic diagnosis can be challenging. We reviewed all patellar tumors at one institution and reviewed the literature.

MATERIALS AND METHODS

In an evaluation of the database at one institution from 1916 to 2009, 23,000 bone tumors were found. Of these, 41 involved the patella. All had imaging studies and microscopic diagnostic confirmation. All medical records, imaging studies, and pathology were reviewed.

RESULTS

There were 15 females and 26 males, ranging from 8 to 68 years old (average 30). There were 30 benign tumors; eight giant cell tumors, eight chondroblastomas, seven osteoid osteomas, two aneurysmal bone cysts, two ganglions, one each of chondroma, exostosis, and hemangioma. There were 11 malignant tumors: five hemangioendotheliomas, three metastases, one lymphoma, one plasmacytoma, and one angiosarcoma.

CONCLUSION

Patellar tumors are rare and usually benign. As the patella is an apophysis, the most frequent lesions are giant cell tumor in the adult and chondroblastoma in children. Osteoid osteomas were frequent in our series and easily diagnosed. Metastases are the most frequent malignant diagnoses in the literature; in our series malignant vascular tumors were more common. These lesions are often easily analyzed on radiographs. CT and MR define better the cortex, soft tissue extension, and fluid levels. This study presents the imaging patterns of the more common patellar tumors in order to help the radiologist when confronted with a lesion in this location.

Novel POMGNT1 point mutations and intragenic rearrangements associated with muscle-eye-brain disease

Congenital muscular dystrophies due to defects in genes encoding proteins involved in α-dystroglycan (α-DG) glycosylation are a heterogeneous group of muscle disorders variably associated with central nervous system and eye abnormalities. One of the more severe is muscle-eye-brain disease (MEB). Mutations in genes coding for proven or putative glycosyltransferases (POMT1, POMT2, POMGnT1, fukutin, FKRP, and LARGE), the DPM3 gene encoding a DOL-P-Man synthase subunit, and the DAG1 gene encoding α-dystroglycan, have been associated with altered α-DG glycosylation.

We report new POMGnT1 mutations and evaluate protein expression in 3 patients and 2 foetuses with variably severe MEB features. We identify two new point mutations (c.643 C > T, c.1863delC), one new intragenic rearrangement (deletion of exons 2–8), and a new intron retention (between exons 21 and 22) resulting from a known point mutation c.1895 + 1 G > T. Our study provides further evidence that rearrangements of the POMGnT1 gene are relatively common. Importantly, if heterozygous, they can be missed on standard genomic DNA sequencing. POMGNT1 protein analysis in 3 patients showed that the severity of the phenotype does not correlate with protein expression. Cerebral MRI is important for identifying MEB and α-dystroglycanopathy phenotypes in children and foetuses, and hence for directing the genetic analysis.

Single-molecule mechanical unfolding of amyloidogenic beta2-microglobulin: the force-spectroscopy approach

The recombinant production of a novel chimeric polyprotein is described. The new protein contains either wild-type beta(2)-microglobulin (beta(2)m) or its truncated variant (DeltaN6 beta(2)m) (see picture). Structural characterization is achieved by means of single-molecule force spectroscopy studies of specific beta(2)m regions which could be involved in amyloidogenesis.

Enhanced fluorescence by metal nanospheres on metal substrates

We investigate the metal enhanced fluorescence by silver nanospheres on a thin silver substrate. Experimental measurements for core/shell colloidal nanocrystals embedded in a polymer matrix show a fluorescence enhancement factor of about 9. We apply the discrete dipole approximation method to describe the local-field enhancement factor (LFEF). We find that the observed fluorescence enhancement is related to the broad LFEF profile induced by the substrate.

Micro/Nanoscale Parallel Patterning of Functional Biomolecules, Organic Fluorophores and Colloidal Nanocrystals

We describe the design and optimization of a reliable strategy that combines self-assembly and lithographic techniques, leading to very precise micro-/nanopositioning of biomolecules for the realization of micro- and nanoarrays of functional DNA and antibodies. Moreover, based on the covalent immobilization of stable and versatile SAMs of programmable chemical reactivity, this approach constitutes a general platform for the parallel site-specific deposition of a wide range of molecules such as organic fluorophores and water-soluble colloidal nanocrystals. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11671-009-9386-7) contains supplementary material, which is available to authorized users.

Exploring local flexibility/rigidity in psychrophilic and mesophilic carbonic anhydrases

Molecular flexibility and rigidity are required to determine the function and specificity of protein molecules. Some psychrophilic enzymes demonstrate a higher catalytic efficiency at low temperatures, compared to the efficiency demonstrated by their meso/thermophilic homologous. The emerging picture suggests that such enzymes have an improved flexibility of the structural catalytic components, whereas other protein regions far from functional sites may be even more rigid than those of their mesophilic counterparts. To gain a deeper insight in the analysis of the activity-flexibility/rigidity relationship in protein structure, psychrophilic carbonic anhydrase of the Antarctic teleost Chionodraco hamatus has been compared with carbonic anhydrase II of Bos taurus through fluorescence studies, three-dimensional modeling, and activity analyses. Data demonstrated that the cold-adapted enzyme exhibits an increased catalytic efficiency at low and moderate temperatures and, more interestingly, a local flexibility in the region that controls the correct folding of the catalytic architecture, as well as a rigidity in the hydrophobic core. The opposite result was observed in the mesophilic counterpart. These results suggest a clear relationship between the activity and the presence of flexible and rigid protein substructures that may be useful in rational molecular and drug design of a class of enzymes playing a key role in pathologic processes.