Real-time PCR in a plastic chip based on solid state FRET

We show a novel solid state optical detection platform, integrated in a plastic biochip, based on colloidal nanocrystal FRET donors. The approach exploits a "smart" polymeric layer with both optical and biorecognition properties that allows real-time monitoring of biomolecular interactions and quantitative analyses of real-time PCR. The proposed strategy, demonstrated here for DNA detection, may open interesting perspectives for a wide range of applications, such as for proteomic studies.

Molecular characterization of 6 unrelated Italian patients with 5alpha-reductase type 2 deficiency

Steroid 5alpha-reductase (5alphaR) deficiency (OMIM number #264600) is a rare 46,XY disorder of sex differentiation caused by mutations in the 5alphaR type 2 gene (SRD5A2) resulting in dihydrotestosterone deficiency during fetal development. We report on the analysis of the SRD5A2 gene in 6 unrelated 46,XY Italian patients with external genitalia morphology ranging from predominantly female to nearly completely male. Three subjects were seen and assessed at birth, 1 patient was referred to us before puberty, and 2 at postpubertal age. Six different causative mutations (5 missense and 1 nonsense) and a rare polymorphism were identified. Four patients presented homozygous single-base substitutions. These SRD5A2 mutations were located in exon 2 (variant Cys133Gly), exon 4 (Gly196Ser and Ala207Asp) and exon 5 (Tyr235Phe). A fifth subject was a compound heterozygote who carried a nonsense mutation in exon 1 (Trp53X) and a second SRD5A2 alteration in exon 5 (Tyr235Phe). The final patient presented a mutation in only 1 allele (Gly34Trp) together with the Ala49Thr variant. The molecular characterization of these patients made it possible to identify novel mutations and to confirm, before gender assignment or any surgical approach, the suspected 5alphaR deficiency in 2 newborns, 1 of whom had inconclusive hormonal data. 5alphaR deficiency in subjects without parental consanguinity and the presence of compound heterozygotic patients suggest that SRD5A2 mutations carrier frequency may be higher than previously thought.

Metal-enhanced fluorescence of colloidal nanocrystals with nanoscale control

Engineering the spectral properties of fluorophores, such as the enhancement of luminescence intensity, can be achieved through coupling with surface plasmons in metallic nanostructures. This process, referred to as metal-enhanced fluorescence, offers promise for a range of applications, including LEDs, sensor technology, microarrays and single-molecule studies. It becomes even more appealing when applied to colloidal semiconductor nanocrystals, which exhibit size-dependent optical properties, have high photochemical stability, and are characterized by broad excitation spectra and narrow emission bands. Other approaches have relied upon the coupling of fluorophores (typically organic dyes) to random distributions of metallic nanoparticles or nanoscale roughness in metallic films. Here, we develop a new strategy based on the highly reproducible fabrication of ordered arrays of gold nanostructures coupled to CdSe/ZnS nanocrystals dispersed in a polymer blend. We demonstrate the possibility of obtaining precise control and a high spatial selectivity of the fluorescence enhancement process.

Respiratory epithelial adenomatoid hamartoma of the maxillary sinus: case report

The case is described of a male patient with respiratory epithelial adenomatoid hamartoma of the left maxillary sinus that initially presented as a chronic sinus inflammation. This benign lesion is characterized by glandular proliferation originating from the surface of the respiratory epithelium. Maxillary sinus localisation is very rare but is very important to be able to distinguish hamartomas from schneiderian papillomas of the inverted type and adenocarcinomas, potentially requiring aggressive surgical treatment. Moreover, misinterpretation of the respiratory epithelial adenomatoid hamartoma as chronic sinus inflammation may result in inadequate treatment. The clinical and pathological features of this lesion are discussed.

Charge transport in disordered films of non-redox proteins

Electrical conduction in solid state disordered multilayers of non-redox proteins is demonstrated by two-terminal transport experiments at the nanoscale and by scanning tunneling microscopy (STM/STS experiments). We also show that the conduction of the biomolecular films can be modulated by means of a gate field. These results may lead to the implementation of protein-based three-terminal nanodevices and open important new perspectives for a wide range of bioelectronic/biosensing applications.

Axillary lymph node nanometastases are prognostic factors for metastatic relapse in breast cancer patients

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Background: Early breast cancer presents with a remarkable and largely unaccounted for heterogeneity of outcomes. Undetected, microscopic lymph node tumor deposits may account for a significant fraction of this prognostic diversity. Thus, we systematically evaluated the presence of lymph node tumor cell deposits <0.2 mm in diameter [pN0(i+), nanometastases], and analysed their prognostic impact. Methods: Seven hundred and two single institution, consecutive patients with 8 years of median follow-up were studied. To maximize the chances of detecting micro and nanometastases, whole-axilla dissections were analysed. pN0 cases were systematically reevaluated by step sectioning and anti-cytokeratin immunohistochemical analysis of 6676 corresponding dissected lymph nodes. The risk of first adverse events and of distant relapse of bona fide pN0 patients was compared with that of pN0(i+), pN1mi and pN1 cases. Crude cumulative incidence (CCI) curves were used to estimate the cumulative probability of occurrence of adverse events. CCI curves were compared by the Gray’s test. A proportional sub distribution hazard (SDH) regression model was utilized to assess the difference among CCI curves of pN0(i+) versus pN0(i-), and of pN1mi versus pN0(i+). Competing risks were accounted for and regression models were adjusted for established breast cancer prognostic factors, i.e. grading, pathological T stage and age. Proportional SDH assumptions were checked using Schoenfeld-type residuals. Results: A pN0(i+) status was shown to be a strong risk factor for event-free survival (P<0.0005) and for metastatic relapse in both univariate and multivariate analyses accounting for competing risks and adjusted for grading, pathological T stage and age. Conclusions: Our findings demonstrate that nanometastases are an important risk factor in breast cancer. These results support the inclusion of procedures for nanometastasis detection in TNM pathological staging.

No significant financial relationships to disclose.

Self-assembling of proteins and enzymes at nanoscale for biodevice applications

Different nanotechnological strategies have been selected to implement biomolecular devices following a bottom-up or top-down approach depending on the biomolecule and on its functionality. Biomolecules have particular functionality and self-assembling capabilities that can be exploited for the implementation of both bioelectronic devices and multipurpose engineered biosurfaces. Surface preparation with supramolecular methods and microcontact printing have been developed and optimised to realise suitable functionalised surfaces. These surfaces can be used to link metalloproteins and enzymes for the implementation of nanobioelectronic devices and planar biosensors or to bind cells in order to promote their growth along predefined tracks and grooves. Some possible applications of these biosurfaces are shown and discussed. Results are presented for the realisation of a biomolecular nanodevice working in air based on the metalloprotein azurin immobilised in the solid state, the formation and characterisation of functional glutamate Dehydrogenase monolayers for nanobiosensing applications, the results of soft lithography processes on azurin for biosensor implementation, and the development of physiological self-assembled patterns of laminin-1 for cell culture applications and hybrid devices.

Epidemiology of status epilepticus in a rural area of northern Italy: a 2-year population-based study

We performed a 2-year population-based study on status epilepticus (SE) in adults in the rural area of Lugo di Romagna, northern Italy, to verify whether an area of low-level urbanization has a lower risk of occurrence of SE (as recently suggested), different clinical features and short-term prognosis than areas of high-level urbanization. We found crude and age- and sex-adjusted annual incidence rates of SE of 16.5/100 000 and 11.6/100 000, respectively. In patients under 60 years crude incidence was 2.9/100 000 and in the elderly (>/=60 years) 38.6/100 000. Acute symptomatic SE accounted for 30% and a cerebrovascular pathology was the most frequently associated etiologic condition (60%). A history of seizures was reported in 41% of patients. The first therapeutic intervention was mainly benzodiazepines (lorazepam 46%; diazepam 33%). The 30-day case fatality was 7%. We observed that the adult population of an area with a low level of urbanization has the same risk for SE, clinical features and short-term prognosis as European urban areas. The only contrasting result is the 30-day case fatality of 7% against the 39% found in the other Italian study (Bologna), despite the similarity of the SE features in these two areas of the same region. We infer that the short-term prognosis of SE could also be considerably influenced by differences in health service organization (and hence management) possibly due to different levels of urbanization.

De novo pure 12q22q24.33 duplication: First report of a case with mental retardation, ADHD, and Dandy-Walker malformation

We present a patient with a de novo 12q nonmosaic pure duplication characterized by multiple minor anomalies and Dandy-Walker malformation. A neurological and behavioral assessment revealed psychomotor retardation and attention deficit/hyperactivity disorder (ADHD), with neurobehavioral abnormalities (auto- and heteroaggressive behavior). Fluoxetine therapy in this case markedly improved the neurobehavioral profile, with a decreased level of aggression. To define the extension of the duplicated region, we performed FISH analyses by using YAC probes. The analyses revealed a tandem duplication of the 12q22q24.33 region, with the proximal breakpoint located between 96.5 and 97.6 cM and the distal one between 154 and 161 cM. This is the first case of pure de novo duplication involving the 12q22q24.33 region. To better define the clinical phenotype associated with 12q partial duplication, we compared our case with the four patients with similar pure duplications previously described.

Study of the surface morphology of a cholesteryl tethering system for lipidic bilayers

The immobilization of functional molecules embedded in lipidic membranes onto inorganic substrates is of great interest for numerous applications in the fields of biosensors and biomaterials. We report on the preparation and the morphological characterization of a tethering system for lipidic bilayers, which is based on cholesteryl derivatives deposited on hydrophilic surfaces by self-assembling and microcontact printing techniques. The investigation of the structural properties of the realized films by atomic, lateral, and surface potential microscopy allowed us to assess the high quality of the realized cholesteryl layers.

Retention of nativelike conformation by proteins embedded in high external electric fields

In this Communication, we show that proteins embedded in high external electric fields are capable of retaining a nativelike fold pattern. We have tested the metalloprotein azurin, immobilized onto SiO2 substrates in air with proper electrode configuration, by applying static fields up to 10(6)-10(7) Vm. The effects on the conformational properties of protein molecules have been determined by means of intrinsic fluorescence measurements. Experimental results indicate that no significant field-induced conformational alteration occurs. Such results are also discussed and supported by theoretical predictions of the inner protein fields.

Solid state protein monolayers: Morphological, conformational, and functional properties

We have studied the morphological, conformational, and electron-transfer (ET) function of the metalloprotein azurin in the solid state, by a combination of physical investigation methods, namely atomic force microscopy, intrinsic fluorescence spectroscopy, and scanning tunneling microscopy. We demonstrate that a "solid state protein film" maintains its nativelike conformation and ET function, even after removal of the aqueous solvent.

Formation and characterization of glutamate dehydrogenase monolayers on silicon supports

In this paper we have tested two different procedures (the "three-step" and the "four-step" procedures) for the covalent immobilization of glutamate dehydrogenase (GDH) onto silicon supports. Atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), fluorescence spectroscopy and an enzymatic assay were used to probe the structure and activity of the immobilized enzyme. Our results demonstrate that coupling through the "three-step" procedure does not significantly affect either the fold pattern or the activity of the enzyme, suggesting that this method could be ideally suited to the development of high quality monolayers for use in enzyme-based planar biosensors.