Safety and adverse reactions in subcutaneous allergen immunotherapy: a review

BACKGROUND

Allergen immunotherapy (AIT) is the only treatment which acts on the causes of allergic diseases by modifying their natural history. In the eighties subcutaneous immunotherapy (SCIT) with high biological power allergen extracts caused a number of severe systemic reactions and also fatalities in the UK and the US, resulting in its limitation and in the introduction of other routes of administration. A decisive advance for SCIT safety was understanding that the major cause of mortality was injecting the allergen extract to patients with uncontrolled asthma at the time of injection.

AREAS COVERED

This awareness resulted in a significant decrease in fatalities, but not in their abolition. In 2019, an increase in SCIT-related mortality was observed, suggesting to continue the research for still unidentified factors favoring severe reactions, such as the administration of a wrong extract or of allergen doses higher than listed, unintentional intravenous administration, and missed dose reduction after protracted interruption. Moreover, in the context of the improving of the safety, the role played in tolerance-promoting by adjuvants such as CpG oligodeoxynucleotides has to be taken into account, as well as the potential preventive effect performed by the monoclonal anti-IgE antibody omalizumab against the exacerbation of severe reactions during SCIT.

CONCLUSION

The safety of SCIT is good, but the research to improve it further must continue. In particular, the pathophysiological mechanisms related to AIT for inhalants and for Hymenoptera venom should be studied, based on the evident diversity demonstrated by the complete absence of fatal reactions to Hymenoptera venom immunotherapy from its introduction in comparison with the history of serious and fatal offenses examined in this review.

Monolithic AlGaAs second-harmonic nanoantennas: erratum

Figure 1(b) in [V. F. Gili et al, Opt. Express24, 15965 (2016)10.1364/OE.24.015965] is corrupted and is corrected in this erratum.

Frequency doubling and parametric fluorescence in a four-port aluminum gallium arsenide photonic chip

In this Letter, we report on the fabrication and characterization of a monolithic III-V semiconductor photonic chip, designed to perform nonlinear parametric optical processes for frequency conversion and non-classical state generation. This chip co-integrates an AlGaAs microdisk that is evanescently coupled to two distinct suspended waveguides designed for light injection and collection around 1600 nm and 800 nm, respectively. Quasi-phase matching provided by the resonator geometry and material symmetry, resonant field enhancement, and confinement ensure efficient nonlinear interactions. We demonstrate second-harmonic generation efficiency of 5%W^-1 and a biphoton generation rate of 1.2 kHz/µW through spontaneous down-conversion.

A bio-psycho-social approach in elderly population: outcome of adapted physical activity in patients with osteoarthritis

BACKGROUND

The beneficial effect of physical activity on a large spectrum of diseases is well known, with particular importance for elderly people. Among the different types of activity, adapted physical activity (APA) has been applied in a number of disease-related physical deficit.

OBJECTIVE

The purpose of this study is to determine the outcome of a six months APA program in elder patients with osteoarthritis concerning physical and functional health and as second endpoint to determine the potential effect of AFA on reducing the risk of institutionalization.

METHODS

The clinical indexes used to assess the outcome included the Blaylock Risk Assessment Screening Score (BRASS), the Psychological General Well Being Index (PGWBI), the Cumulative Illness Rating Scale (CIRS), the Short Physical Performance Battery (SPPB), and the visual analogue scale (VAS).

RESULTS

A significant difference (p = 0.047) between the pre-APA and the post-APA value was found for BRASS, and highly significant differences (p <0.0001) were found for SPBB and VAS.

CONCLUSIONS

These findings show that a six months APA program in elder patients with osteoarthritis improves physical function, reduces pain intensity and decreases the risk of institutionalization. Moreover the positive outcome of APA we found in elder patients with osteoarthritis suggests a more frequent use of such rehabilitation approach, also evaluating its economic impact on this disease.

Two decades with omalizumab: what we still have to learn

From its availability for clinical use nearly two decades ago for severe asthma, omalizumab has gained strong evidence of efficacy and safety in the treatment of severe asthma not controlled by standard-of-care therapy. It has been acknowledged by Global Initiative on Asthma guidelines as add-on therapy against severe uncontrolled asthma. Thanks to controlled trials supporting its efficacy, omalizumab has also been licensed for the treatment of chronic spontaneous urticaria. The optimal duration of treatment in either disease has not been established. Despite its high price, omalizumab appears to be cost-effective in severe uncontrolled asthma as well as in chronic urticaria. The literature suggests a wide range of applications for omalizumab in various disorders regardless of allergic or non-allergic pathophysiology.

Microscopic Nanomechanical Dissipation in Gallium Arsenide Resonators

We report on a systematic study of nanomechanical dissipation in high-frequency (≈300  MHz) gallium arsenide optomechanical disk resonators, in conditions where clamping and fluidic losses are negligible. Phonon-phonon interactions are shown to contribute with a loss background fading away at cryogenic temperatures (3 K). Atomic layer deposition of alumina at the surface modifies the quality factor of resonators, pointing towards the importance of surface dissipation. The temperature evolution is accurately fitted by two-level systems models, showing that nanomechanical dissipation in gallium arsenide resonators directly connects to their microscopic properties. Two-level systems, notably at surfaces, appear to rule the damping and fluctuations of such high-quality crystalline nanomechanical devices, at all temperatures from 3 to 300 K.

Directionally induced quasi-phase matching in homogeneous AlGaAs waveguides

We report on the experimental observation of quasi-phase matching in a homogeneous waveguide. By fabricating a monolithic snake-shaped suspended AlGaAs nanowire on a (001) GaAs wafer, we demonstrate the unraveled version of a χ⁽²⁾ whispering-gallery-mode microdisk, obtaining second-harmonic generation in the optical telecom wavelength range. With a radius of curvature of 50 μm and four spatial oscillations along the (110) average direction, a splitting of the second-harmonic spectrum occurs around the phase-matching wavelength of the corresponding straight waveguide. This splitting, which increases as the radius of curvature decreases, provides a useful degree of freedom for the design of small-footprint nonlinear photonic devices on-chip.

Controlling second-harmonic generation at the nanoscale with monolithic AlGaAs-on-AlOx antennas

We review recent achievements in the field of nanoscale nonlinear AlGaAs photonics based on all-dielectric optical antennas. After discussing the motivation and main technological challenges for the development of an AlGaAs monolithic platform for χ ⁽²⁾ nonlinear nanophotonics, we present numerical and experimental investigations of the second-order nonlinear response and physical reasons for high efficiency of second-order nonlinear interactions in the AlGaAs nano-antennas. In particular, we emphasize the role of the dipolar resonances at the fundamental frequency and the multipolar resonances at the second harmonic wavelength. We also discuss second-harmonic generation directionality and show possible strategies to engineer the radiation pattern of nonlinear antennas.

Light-Mediated Cascaded Locking of Multiple Nano-Optomechanical Oscillators

Collective phenomena emerging from nonlinear interactions between multiple oscillators, such as synchronization and frequency locking, find applications in a wide variety of fields. Optomechanical resonators, which are intrinsically nonlinear, combine the scientific assets of mechanical devices with the possibility of long distance controlled interactions enabled by traveling light. Here we demonstrate light-mediated frequency locking of three distant nano-optomechanical oscillators positioned in a cascaded configuration. The oscillators, integrated on a chip along a common coupling waveguide, are optically driven with a single laser and oscillate at gigahertz frequency. Despite an initial mechanical frequency disorder of hundreds of kilohertz, the guided light locks them all with a clear transition in the optical output. The experimental results are described by Langevin equations, paving the way to scalable cascaded optomechanical configurations.

Polarization properties of second-harmonic generation in AlGaAs optical nanoantennas

Manipulating light at the nanoscale by means of dielectric nanoantennas recently received renewed attention thanks to the development of key enabling fabrication tools in semiconductor technology, combined with the extremely low losses exhibited by dielectrics in the optical regime. Nanostructures based on III-V type semiconductors, characterized by an intrinsic broken symmetry down to a single elementary cell, has already demonstrated remarkable nonlinear conversion efficiencies at scales well below the operating wavelength. In this Letter, we thoroughly investigate the emission properties of second-harmonic generation (SHG) in AlGaAs monolithic nanoantennas. Our findings point toward the pivotal role of volume susceptibility in SHG, further unraveling the physics behind the nonlinear processes in these systems. The extremely high SHG efficiency attained, together with the control over the polarized emission in these nanoantennas, constitute key ingredients for the development of tunable nonlinear metasurfaces.

Monolithic AlGaAs second-harmonic nanoantennas

We demonstrate monolithic aluminum gallium arsenide (AlGaAs) optical nanoantennas. Using a selective oxidation technique, we fabricated epitaxial semiconductor nanocylinders on an aluminum oxide substrate. Second harmonic generation from AlGaAs nanocylinders of 400 nm height and varying radius pumped with femtosecond pulses delivered at 1554-nm wavelength has been measured, revealing a peak conversion efficiency exceeding 10^-5 for nanocylinders with an optimized geometry.

HIV treatment and care among Italian inmates: a one-month point survey

Background

HIV infection, with an estimated prevalence be between 2 and 50 times those of the general adult population is a major health challenge for prison authorities worldwide. Since no nationwide surveillance system is present in Italy, data on HIV prevalence and treatment in prisons are limited to only a few and small observational studies. We aimed to estimate HIV prevalence and obtain an overview on diagnostic and therapeutic activities concerning HIV infection in the Italian penitentiary system.

Methods

We piloted a multi-centre cross-sectional study investigating the prevalence of HIV infection and assessing HIV-related medical activities in Italian correctional institutions.

Results

A total of 15,675 prisoners from 25 institutions, accounting for approximately one-fourth of the prison inmates in Italy, were included in the study, of whom, 97.7 % were males, 37.1 % foreigners and 27 % had a history of intravenous drug addiction. HIV-tests were available in 42.3 % of the total population, with a known HIV Infection proportion of 5.1 %. In the month prior to the study, 604 of the 1,764 subjects who entered prison were tested for HIV, with a HIV-positive prevalence of 3.3 %. Among the 338 HIV-positive prisoners, 81.4 % were under antiretroviral treatment and 73.5 % showed undetectable HIV-RNA. In 23/338 (6.8 %) a coinfection with HBV and in 189/338 (55.9 %) with HCV was also present. Among the 67 (19.8 %) inmates with HIV who did not receive HIV treatment, 13 (19.5 %) had T-CD4+ count <350 cells/mm³ and 9 (69.2 %) of these had refused the treatment. The majority of the inmates with HIV-infection were on a PI-based (62.5 %) or on NNRTIs-based (24.4 %) regimen. Only a minority of patients received once daily regimens (17.2 %).

Conclusions

Although clinical and therapeutic management of HIV infection remains difficult in Italian prisons, diagnostics, treatment and care were offered to the majority of HIV-infected inmates. Specific programs should be directed towards the prison population and strict cooperation between prison and health institutions is needed to increase HIV treatment.

Enhanced second-harmonic generation from magnetic resonance in AlGaAs nanoantennas

We designed AlGaAs-on-aluminium-oxide all-dielectric nanoantennas with magnetic dipole resonance at near-infrared wavelengths. These devices, shaped as cylinders of 400nm height and different radii, offer a few crucial advantages with respect to the silicon-on-insulator platform for operation around 1.55μm wavelength: absence of two-photon absorption, high χ((2)) nonlinearity, and the perspective of a monolithic integration with a laser. We analyzed volume χ((2)) nonlinear effects associated to a magnetic dipole resonance in these nanoantennas, and we predict second-harmonic generation exceeding 10(-3) efficiency with 1GW/cm(2) of pump intensity.

High-frequency nano-optomechanical disk resonators in liquids

Nano- and micromechanical resonators are the subject of research that aims to develop ultrasensitive mass sensors for spectrometry, chemical analysis and biomedical diagnosis. Unfortunately, their merits generally diminish in liquids because of an increased dissipation. The development of faster and lighter miniaturized devices would enable improved performances, provided the dissipation was controlled and novel techniques were available to drive and readout their minute displacement. Here we report a nano-optomechanical approach to this problem using miniature semiconductor disks. These devices combine a mechanical motion at high frequencies (gigahertz and above) with an ultralow mass (picograms) and a moderate dissipation in liquids. We show that high-sensitivity optical measurements allow their Brownian vibrations to be resolved directly, even in the most-dissipative liquids. We investigate their interaction with liquids of arbitrary properties, and analyse measurements in light of new models. Nano-optomechanical disks emerge as probes of rheological information of unprecedented sensitivity and speed, which opens up applications in sensing and fundamental science.

May chronic rhinosinusitis in children be diagnosed by clinical symptoms?

OBJECTIVES

Chronic rhinosinusitis (CRS) is a common disease in childhood but is often underdiagnosed because the symptoms are subtle and similar to other nasal pathologies. No clinical symptom is pathognomonic, and consensus documents suggest nasal fibroendoscopy (NF) or imaging criteria (computed tomography, magnetic resonance imaging) as the gold standards for diagnosis of CRS. However, considering the frequent unavailability of such tools to physicians, we designed this study to evaluate whether combinations of symptoms may achieve a clinical diagnosis of CRS in children as confirmed by NF.

METHODS

The study population consisted of 275 children with a clinical diagnosis of CRS, in 228 of whom diagnosis of CRS was confirmed by NF, while in 47 diagnosis was not confirmed by NF and they served as the control group. The symptoms considered were nasal obstruction, nasal discharge, cough, facial pain, and halitosis, using for statistical analysis multivariate logistic regression, Wald tests, and receiver operating characteristic (ROC) curve.

RESULTS

The multivariate logistic regression for CRS symptoms indicated rhinorrea as the strongest predictor of CRS. With three symptoms the probability of CRS was from 60% to 75% without rhinorrea and 77-91% in the presence of this symptom, with four symptoms the probability was over 93%, and with all the five symptoms the probability of having CRS was virtually 100%.

CONCLUSIONS

These findings suggest that an initial symptoms assessment may help to recognize children with a high probability of CRS, thus reducing the need of NF or imaging techniques.

AlGaAs guided-wave second-harmonic generation at 2.23 μm from a quantum cascade laser

We demonstrate the frequency doubling of a quantum cascade laser in a multilayered, partially oxidized GaAs/AlOx waveguide. Using the waveguide width to fulfill the phase-matching condition, the second harmonic is generated in the wavelength range between 2.2 and 2.4 μm, where not many semiconductor sources are commercially available to date. We discuss the impact of a few fabrication and experimental parameters on the conversion efficiency, an essential step toward the improvement and practical implementation of this proof-of-principle semiconductor microsystem.

Second-harmonic generation in AlGaAs microdisks in the telecom range

We report on second-harmonic generation in whispering-gallery-mode AlGaAs microcavities suspended on a GaAs pedestal. Frequency doubling of a 1.58 μm pump is observed with 7×10(-4)   W(-1) conversion efficiency. This device can be integrated in a monolithic photonic chip for classical and quantum applications in the telecom band.

A role for Waldeyer's ring in immunological response to allergens

OBJECTIVE

Adenoids, tubal tonsil, palatine tonsil, and lingual tonsil are immunological organs included in the Waldeyer's ring, the basic function of which is the antibody production to common environmental antigens. Adenoidal hypertrophy (AH) is a major medical issue in children, and adenoidectomy is still the most used treatment worldwide. The response of adenoids to allergens is a good model to evaluate their immunological function. This report assessed the immunological changes in adenoid tissues from children with allergic rhinitis (AR) undergoing sublingual immunotherapy (SLIT).

METHODS

Adenoid samples from 16 children (seven males, nine females, mean age 7.12 years) with AH and clinical indication to adenoidectomy were collected. Of them, five children were not allergic and 11 had house dust mite and grass pollen-induced AR. Among allergic children, in four AR was treated by antihistamines while in seven AR was treated by high-dose SLIT during 4-6 months. The evaluation addressed the T helper 1 (Th1), Th2, and Th3 cells by performing a PCR array on mRNA extracted from adenoid samples.

RESULTS

In non-allergic children, a typical Th1 pattern was found. SLIT induced a strong down-regulation of genes involved in Th2 and Th1 activation and function. In particular, in SLIT-treated allergic children IL-4, CCR2, CCR3, and PTGDR2 (Th2 related genes) and CD28, IL-2, and INHA (Th1 related genes) expression was reduced, compared with children treated with antihistamines.

CONCLUSIONS

These preliminary findings warrant investigation in trials including larger numbers of patients, but indicate that hypertrophic adenoids of allergic children have the typical response to the specific allergen administered by SLIT. This should suggest that one should reconsider the immunological role of adenoids.

Tunable quantum dot parametric source

We report on the modeling of an electrically pumped nonlinear source for spontaneous parametric down-conversion in an AlGaAs single-sided Bragg waveguide. Laser emission from InAs quantum dots embedded in the waveguide core is designed to excite a Bragg pump mode at 950 nm. This mode is phase matched with two cross-polarized total-internal-reflection fundamental signal and idler modes around 1900 nm. Besides numerically evaluating the source efficiency, we discuss the crucial role played by the quantum dots in the practical implementation of the phase-matching condition along with the tuning capabilities of this promising active device.

Direct Bell states generation on a III-V semiconductor chip at room temperature

We demonstrate the direct generation of polarization-entangled photon pairs at room temperature and telecom wavelength in an AlGaAs semiconductor waveguide. The source is based on spontaneous parametric down-conversion with a counterpropagating phase-matching scheme. The quality of the two-photon state is assessed by the reconstruction of the density matrix giving a raw fidelity to a Bell state of 0.83; a theoretical model, taking into account the experimental parameters, provides ways to understand and control the amount of entanglement. Its compatibility with electrical injection, together with the high versatility of the generated two-photon state, make this source an attractive candidate for completely integrated quantum photonics devices.

Sinus imaging for diagnosis of chronic rhinosinusitis in children

Chronic rhinosinusitis (CRS) is a relatively common disease in children but is often overlooked because at times the clinical symptoms are subtle and nonspecific. This makes imaging very important in the diagnosis. Among the different techniques, plain radiography has limited utility,whereas CT scan and MRI have a major role in evaluating the modifications caused by the disease. In particular, a CT scan provides higher resolution of bone and soft tissue and removes the overlapping structures that are present in conventional radiography. CT is recommended in isolated sphenoid sinusitis, is essential in diagnosing fungal sinusitis, and is the technique of choice when orbital complications are suspected. MRI allows investigation of not only the morphology of structures, but their intrinsic biophysical and biochemical properties, such as water content, cellular density, lipid or blood product deposits, and fibrosis. MRI allows better soft tissue differentiation and high spatial resolution images depicting fine details. When indicated, MRI with contrast gadolinium-based agents may better characterize the local disease extension or its diffusion beyond paranasal and nasal cavities and has excellent contrast resolution. A combination of CT and MRI is useful in cases of diagnostic difficulties,especially when complications are involved.

PET in the clinical work-up of patients with spondylodiscitis: a new tool for the clinician?

AIM

The role of 18F-fluorodeoxyglucose-positron-emission tomography (FDG-PET) in the clinical management of patients with inflammatory diseases (e.g., chronic inflammatory diseases, fever of unknown origin, ostemyelitis, prosthesis infections) is still under investigation. The aim of the present study was to evaluate the usefulness of PET in the diagnostic work-up of patients with spondylodiscitis and to compare it with magnetic resonance imaging (MRI).

METHODS

This retrospective study included 33 patients with suspected/confirmed spondylodiscitis. Two groups were created: 1) disease definition (n=24); and 2) treatment assessment (N.=16, 21 exams). Disease status was defined on the basis of data collected for symptoms, hematological parameters, imaging studies and histological findings, when available. Qualitative and semiquantitative analysis of the PET images was performed. The minimum duration of follow-up was 6 months.

RESULTS

For the Disease Definition group, FDG-PET showed a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 92.9%, 50%, 72.2%, 83.3%, and 75%, respectively, and MRI showed a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%, 50%, 76.9%, 100%, and 81.3%, respectively. For the Treatment Assessment group, FDG-PET showed a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 90%, 81.8%, 81.8%, 90%, and 85.7%, respectively, and MRI showed a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%, 16.7%, 58.3%, 100% and 61.5%, respectively. No significant differences were observed between qualitative and semiquantitative evaluation of PET scans.

CONCLUSION

PET and MRI showed similar accuracy in the diagnosis of spondylodiscitis, indicating that PET can be used when MRI is doubtful or unavailable. PET was more accurate and more specific than MRI in treatment assessment, suggesting that PET should be preferred over MRI for determining when treatment can be safely discontinued.

Effect of tumor size on the association between ps2 and cathepsin-d in primary breast-cancer

Previous studies have shown that pS2 and cathepsin D are linked in lymph node positive (N+) tumours, but not in tumours from lymph node negative (N-) patients. The purpose of this study was to understand whether or not size would effect the relationship between pS2 and cathepsin D. Findings were further extended to some subgroups of tumours obtained stratifying for T and N and particularly to the small (TI) but aggressive (N+) cancers (T1/N+) and to those of size greater than 2 cm (T2 and T3) but yet node negative (T2+T3/N-). Oestrogen (ER) and progesterone (PR) receptors, pS2 and cathepsin D concentrations were therefore assayed in 355 primary breast cancers. ER, PR, pS2 and cathepsin D did not correlate to nodal status and size of the tumours; no significant differences in the expression of these four biological factors between infiltrating ductal carcinomas without special features (NOS) and non-NOS carcinomas were found. Multivariate analysis performed among cathepsin D, ER, PR and pS2 indicated that, in T1 tumours, pS2 was the most important variable and the best predictor in cathepsin D determination, while such association was absent in T2 and T3 tumours. pS2 and cathepsin D significantly associated also in tumours obtained from N+ patients, and such correlation was highest in T1 tumours with positive axillary nodes (N+/T1). pS2 and cathepsin D did not associate in tumours taken from N- patients. Considering the NOS carcinomas, correlation between pS2 and cathepsin D in the N+, T1 and N+/T1 subgroups was higher in the poorly differentiated grade 3 with respect to grade 1 and grade 2 cancers. The data suggest that pS2 could have a role in cathepsin D expression and we hypothesise that such control could be an early biological event occurring in the development and progression of particularly aggressive (N+/grade 3), small (T1) breast cancers.

Diagnosis of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a rather common disease in children, but its symptoms are often subtle and non-specific and this may result in overlooking a correct diagnosis. In turn, a missed diagnosis of CRS prevents a correct management to be performed and is associated with uneffective investigations and improper treatments. Actually, when CRS symptoms, which are mainly nasal congestion and obstruction, nasal discharge, facial pain, cough, and halitosis, are correctly assessed, the clinical diagnosis of CRS may be achieved, and confirmation may be obtained by imaging criteria or nasal fibroendoscopy. In imaging, computed tomography (CT) is the first choice technique for the evaluation of CRS and is able to provide an anatomic road map when surgery is required. Magnetic resonance imaging (MRI) of the sinuses, orbits, and brain should be performed whenever extensive or multiple complications of sinusitis are suspected. Also for middle ear disorders, CT is the first choice because it detects opacification of the middle ear cavity and mastoid cells, presence of fluids or debris, and allows the ossicular chain and the cortical bone of the mastoid to be evaluated. Another important diagnostic issue is the need to look for disorders that are frequently associated with CRS, such as obstructive sleep apnea syndrome (OSAS), that has some recognized risk factors in adenotonsillar hypertrophy, craniofacial anomalies, obesity, and neuromuscular disorders. Other associated disorders requiring investigation are recurrent or persistent otitis media and difficult asthma.

Pathophysiology, favoring factors, and associated disorders in otorhinosinusology

The pathogenesis of rhinosinusitis (RS) is related to inflammation, caused by infections in the acute form of the disease but also by other agents in the chronic forms. Cytology allows to evaluate the defensive components, such as hair cells and muciparous cells, while the presence in the nasal mucosa of eosinophils, mast cells, bacteria and/or fungal hyphae, or spores indicates the nasal pathology. The anatomic and physiologic characteristics of the otorhinosinusal system account for the frequent concomitant involvement of the different components. The pivotal pathophysiologic sites are the ostiomeatal complex, the spheno-ethmoidal recess, and the Eustachian tube. The latter is the link with acute otitis media (AOM), which is the most common disease in infants and children and has major medical, social, and economic effects. Moreover, because of the strict relationship between upper and lower airways, nasal sinus disease may contribute to asthma and sinusitis may be considered as an independent factor associated with frequent severe asthma exacerbations. Concerning the role of allergy, the available data do not permit to attribute a central role to atopy in sinusitis and thus allergy testing should not be a routine procedure, while an allergologic evaluation may be indicated in children with OM, especially when they have concomitant rhinitis.

Tuning of a nonlinear THz emitter

We numerically study a passive THz source based on difference frequency generation between modes sustained by cylindrical AlGaAs microcavities. We show that ring-like structures are advantageous in that they provide additional degrees of freedom for tuning the nonlinear process and for maximizing the nonlinear overlap integral and conversion efficiency.

Large second-harmonic generation at 1.55 μmin oxidized AlGaAs waveguides

We report on CW second-harmonic generation in selectively oxidized AlGaAs multilayer waveguides. Frequency doubling of a 1.55 μm pump is observed with 2.8% W(-1) conversion efficiency and a maximum second-harmonic power around 0.3 mW. This is the strongest second-harmonic generation ever reported in semiconductor waveguides and an encouraging result toward integrated spontaneous parametric downconversion in the telecom range.

A new hypothesis of pathogenesis based on the divorce between mitochondria and their host cells: possible relevance for Alzheimer's disease

On the basis of not only the endosymbiotic theory of eukaryotic cell organization and evolution but also of observations of transcellular communication via Tunneling NanoTubes (TNTs), the hypothesis is put forward that when mitochondria, which were once independently living prokaryote-like organisms, are subjected to detrimental genetic, toxic, or environmental conditions, including age-related endogenous factors, they can regress towards their original independent state. At that point, they can become potentially pathogenic intruders within their eukaryotic host cell. Because of the protoplasmic disequilibrium caused by an altered, or mutated, mitochondral population, certain host cells with a minimal capacity for self-renewal, such as dopaminergic neurons, risk a loss of function and degenerate. It is also proposed that altered mitochondria, as well as their mutated mtDNA, can migrate, via TNTs, into adjacent cells. In this way, neurodegenerative states are propagated between cells (glia and/or neurons) of the Central Nervous System (CNS) and that this leads to conditions such as Alzheimer's and Parkinson's disease. This proposal finds indirect support from observations on rotenone-poisoned glioblastoma cells which have been co-cultured with non-poisoned cells. Immunocytochemical techniques revealed that mitochondria, moving along the TNTs, migrated from the poisoned cells towards the healthy cells. It has also been demonstrated by means of immunocytochemistry that, in glioblastoma cell cultures, Amyloid Precursor Protein (APP) is present in TNTs, hence it may migrate from one cell to neighbouring cells. This datum may be of high relevance for a better understanding of Alzheimer's Disease (AD) since molecular, cellular, and animal model studies have revealed that the formation of amyloid beta (Abeta) and other derivatives of the APP are key pathogenic factors in AD, causing mitochondrial dysfunction, free radical generation, oxidative damage, and inflammation. Furthermore, the present data demonstrate the presence of alpha-synuclein (alpha-syn) within TNTs, hence a similar pathogenic mechanism to the one surmised for AD, but centred on alpha-syn rather than on Abeta, may play a role in Parkinson's Disease (PD). As a matter of fact, alpha-syn can enter mitochondria and interact with complex I causing respiratory deficiency and increased oxygen free radical production. In agreement with this view, it has been demonstrated that, in comparison with normal subjects, PD patients show a significant accumulation of alpha-syn at Substantia Nigra and Striatal level, predominantly associated with the inner mitochondrial membrane,. These observations suggest that potentially neuropathogenic proteins, such as Abeta and alpha-syn, can not only diffuse via the extracellular space but also move from cell to cell also via TNTs where they can cause mitochondrial damage and cell degeneration. A mathematical model (see Appendix) is proposed to simulate the pathogenic consequences of the migration of altered mitochondria and/or of their mtDNA via TNTs. The results of the present simulation is compatible with the proposal that mutated mitochondrial agents behave as though they were infectious particles migrating through a continuum of interconnected cells.

Microsatellite instability (MSI) as genomic markers in endometrial cancer: toward scientific evidences

Endometrial Cancer is the most frequent tumor in western world nations, with 142,000 new cases each year and 42,000 casualties. This form of cancer typically affects women between 55 and 65 years of age, and ranks fourth among female tumors. Endogenous predisposing conditions to endometrial cancer development are: late menopause, early menarche and hyperestrogenism, while hormone replacement therapy, obesity, alcohol, diabetes, and a diet rich in animal fats as well as chronic liver disease, are the exogenous factors. This tumor may also have an hereditary predisposition, as in the Lynch Syndrome or in HNPCC (Hereditary NonPolyposis Colorectal Cancer), since genetic modifications induced by the "MisMatch Repair" genes lead to a tumoral development susceptibility, not only in the colon. The phenotypical consequences of these genetic modifications may be found in the microsatellite instability (MSI) and in the loss of heterozygosity (LOH), which generate the replication errors in positive phenotypes repeats. These express the incapability to repair short nucleotide insertions or deletions, generated by a wrong DNA replication. Due to such genetic modifications, new allelic variants arise in the endometrial tissue, confirming the high degree of this genetic disorder. Recent studies showed that the MSI and LOH in endometrial cells may be associated with the possible loss in the expression of cellular control and with the possible degeneration of the cell growth phenomenon. There is also a possibility of utilizing these new genetic markers in the endometrial mucosa to study these tissues and to detect any possible neoplastic transformations, thanks to Genomics.

Imaging criteria for diagnosis of chronic rhinosinusitis in children

Symptoms of chronic rhinosinusitis (CRS) are nasal blockage, nasal discharge, postnasal drip, facial pain, headache, and reduction or loss of smell, but they are often subtle and make it difficult to obtain a firm diagnosis based only on clinical data, and especially to distinguish CRS from persistent rhinitis. A diagnosis of certainty of CRS relies upon either direct observation by nasal fibroendoscopy of nasal turbinates, middle meatus, and rhinopharynx, detecting mucopurulent discharge from the middle meatus, and/or oedema or mucosal obstruction, or by imaging of the rhinosinusal cavities. Imaging techniques such as computed tomography (CT) scanning and magnetic resonance (MR) are currently recommended in consensus documents, while plain radiography is considered of poor diagnostic value. However, recent studies indicated that radiography by the Waters'projection had a sensitivity of 84.2% and a specificity of 76.6%, which suggests to use it routinely in suspected CRS, limiting the number of more expensive imaging investigations. This seems important in the current economic landscape that requires a cost-effectiveness evaluation in each diagnostic procedure.

Current management of allergic asthma in children

Asthma in children is characterized by recurring symptoms such as wheezing, breathlessness, and cough, by airflow obstruction and bronchial hyperresponsiveness, and by underlying inflammation. The presence of allergic sensitization, and allergic rhinitis in particular, is strongly associated with asthma. The goal of management of asthma is to achieve and maintain control of the clinical manifestations of the disease. This can be obtained by drug treatment, education of patients and care givers, and, in allergic asthma, by allergen avoidance and specific immunotherapy. The drugs used in asthma can be classified as controllers - such as inhaled corticosteroids (ICS) and leukotriene receptor antagonists - or relievers (bronchodilators to be used during acute exacerbations of asthma). ICS are the most effective anti-inflammatory controllers for the management of persistent asthma in children of all ages, but there is no consensus about the optimal starting dose. Dose-response studies reported marked and rapid improvement in clinical symptoms and lung function at low doses of ICS, and mild asthma is well controlled by such doses in most children, this ensuring good safety. If there is no improvement with the initial low dose of ICS, an increased ICS dose or additional therapy with leukotriene receptor antagonists or long-acting inhaled β2-agonists should be considered. When asthma is caused by allergy to aeroallergens, specific immunotherapy must be taken into account, in its two forms of subcutaneous or sublingual immunotherapy. The former has complete evidence of efficacy, but the sublingual route is safer and more easily accepted by children.

beta-Amyloid fibrillation and/or hyperhomocysteinemia modify striatal patterns of hyaluronic acid and dermatan sulfate: Possible role in the pathogenesis of Alzheimer's disease

A key event in Alzheimer's disease (AD) pathogenesis is the formation of insoluble peptides beta-amyloid aggregates and this process is favoured by a condition of hyperhomocysteinemia. To date, there is growing evidence that implicates glycosaminoglycans (GAGs) in the pathophysiology of amyloidosis but no data are available on the characterization of brain GAGs involved in the enhancing beta-amyloid fibrillogenesis in relationship to their structure and physico-chemical properties. Furthermore, few studies have been performed on the relationship between hyperhomocysteinemia and extracellular matrix (ECM) modifications. The aim of this study was to evaluate the amount and chemical structure of GAGs in rat striatal areas where beta-amyioid fibrillogenesis was induced, and in conditions of hyperhomocysteinemia. The intrastriatal injection of beta-amyloid produced a significant decrease (-40.8%) in the hyaluronic acid (HA) percentage and an increase (+14.5%) in the dermatan sulfate (DS) with a total charge density increasing of 14.9%. A significant decrease (-19.5%) in the HA percentage and an increase (+6.9%) in the DS % was also observed in striata obtained from the hyperhomocysteinemic animals. The total charge density increased by 6.8%. Quite the same trend was observed in rats after intrastriatal injection of beta-amyloid and in a condition of hyperhomocysteinemia. The observed increase of DS concentration and the correspondent decrease of the nonsulfated polymer HA after in vivo treatment with beta-amyloid and in a condition of hyperhocysteinemia support the hypothesis that an increase in local production of sulfated GAGs may reduce beta-amyloid neurotoxicity. However, the consequent modification of the ECM network might impair the extracellular diffusion pathways of different signal molecules and participate in the progression of AD.

Two-photon interference with a semiconductor integrated source at room temperature

We experimentally demonstrate an integrated semiconductor ridge microcavity source of counterpropagating twin photons at room temperature in the telecom range. Based on type II parametric down conversion with a counterpropagating phase-matching, pump photons generate photon pairs with an efficiency of about 10(-11) and a spectral linewidth of 0.3 nm for a 1 mm long sample. The indistiguishability of the photons of the pair is measured via a Hong-Ou-Mandel two-photon interference experiment showing a visibility of 85 %. This work opens a route towards new guided-wave semiconductor quantum devices.

Functional anatomy of the Eustachian tube

The Eustachian tube (ET) is divided in 3 portions: a bony portion, a cartilaginous portion, and a junctional portion. From an anatomical-functional point of view, the bony portion of ET is the region of ventilation and clearance of secretions, and is lined by pseudostratified, ciliated, columnar epithelium, with an anti-gravitational direction of the drainage. The ET in the bony portion is in a state of forced opening. The cartilaginous portion is instead the heart of this dynamic system tube, because the mechanism of opening and closing of the tube is at this level. ET is normally closed, and it opens only during swallowing, being essential for good functioning of the middle ear, because it provides ventilation from the nasopharynx to the middle ear, and, at the same time, clearance of secretions from the middle ear-mastoid unit to the nasopharynx. Moreover, the ET protects the middle ear against nasopharyngeal pressure variations, ascending secretions, and microorganisms. The ability to develop all these functions makes the tube a complex organ.

Treatment of rhinosinusitis: other medical options

Medical options other than antibiotics or corticosteroids for treating rhinosinusitis include non-specific treatments such as nasal decongestants, naso-sinusal washings, antihistamines, antileukotrienes, mucolytic agents, immunomodulators and immunostimulants, as well as specific agents such as antimycotics in fungal sinusitis or antireflux agents in sinusitis associated to gastroesophageal reflux. In subjects with chronic sinusitis and/or nasal polyposis related to aspirin hypersensitivity protocols of desensitization are available. The available scientific evidence is good for naso-sinus washings with saline solutions, antihistamines in acute allergic rhinosinusitis, antileukotrienes in chronic sinusitis, bacterial lysates for prevention of recurrent sinusitis, and aspirin desensitisation in subjects with aspirin-exacerbated respiratory disease with chronic sinusitis and nasal polyposis. The other treatment options are still in search of scientific demonstration.

The clinical spectrum of rhinosinusitis in children

Rhinosinusitis is an extremely common disease that is often underreported, especially in children. Its clinical spectrum includes acute rhinosinusitis (ARS) which may present in the forms of ARS with persistent symptoms and ARS with severe symptoms and chronic rhinosinusitis (CRS), characterized by a duration longer than 12 weeks and prevalence of symptoms such as nasal congestion and cough. Moreover, rhinosinusitis may present with associated disorders, that are nasal polyposis and aspirin sensitivity, asthma, otitis media with effusion, and gastroesophageal reflux. A particular form is fungal rhinosinusitis, presenting in an invasive and noninvasive form, the latter including allergic fungal sinusitis, which is the most common form of fungal rhinosinusitis and should be suspected in children with nasal polyposis and atopy.

Treatment of rhinosinusitis: the role of surgery

The treatment of rhinosinusitis in children is mostly medical. Surgery is indicated in few but important exceptions: orbital or intracranial complications of acute rhinosinusitis not responding to medical therapy, chronic rhinosinusitis (CRS) with persisting sinonasal infection and purulent discharge, cystic fibrosis, ciliary diskinesia, dacryocystitis due to sinusitis and resistant to medical treatment, fungal rhinosinusitis. According to recent data, 50 percent of ENT specialist perform an adenoidectomy to manage CRS before endoscopic sinus surgery (ESS). ESS techniques introduced in mid 90s, has significantly modified the treatment of complications of acute rhinosinusitis and of selected cases of chronic recurrent infections. ESS consists of minimally invasive surgical procedure as middle meatal antrostomy and anterior ethmoidectomy. Evidence suggests that adenoidectomy and ESS are the most frequent surgical procedure performed in RS management.

Sublingual immunotherapy for treating respiratory allergy: a review on its effectiveness and suitability

Sublingual immunotherapy (SLIT) was introduced in the treatment of respiratory allergy as an option to subcutaneous immunotherapy (SCIT), which is clinically effective but has the problem of adverse systemic reactions, quite rare but sometimes life-threatening. A large number of trials, globally evaluated in several meta-analyses, demonstrated that SLIT is an efficacious treatment for allergic rhinitis and allergic asthma and has a satisfactory safety profile, severe reactions being extremely rare, though an increased risk is apparent in subjects undergoing SLIT because of previous systemic reactions to SCIT. The suitability of SLIT is ensured by a good compliance, higher than reported for SCIT, the injections being a major factor for noncompliance with the latter, and by its cost-effectiveness performances. In fact, a number of studies showed that SLIT may be very beneficial to the healthcare system, especially after its stopping, when there is no more the cost of the treatment but its efficacy on symptoms persists.

Economic aspects of sublingual immunotherapy

Allergic rhinitis and asthma have a very high prevalence and constitute a health problem with a relevant burden of disease, concerning medical and economical issues. Among the treatments of allergy, specific immunotherapy (IT) has the capacity to favourably alter the natural history of the disease both during and after its performance, and thus to reduce the direct and indirect costs of allergic rhinitis and asthma. A number of studies reported a cost reduction for traditional, subcutaneous IT (SCIT). We analyzed the available studies on economic evaluation of sublingual immunotherapy (SLIT) in children and adults. Articles were retrieved from Medline and Embase using the terms economic aspects, pharmacoeconomics, cost effectiveness, and sublingual immunotherapy. 18 articles were found in English language, 7 studies investigated the economic advantage of SLIT over standard drug treatment in subjects with respiratory allergy, and 2 of them included a comparison of costs of SCIT and SLIT. The data obtained provide evidence that SLIT is associated to economic advantages and/or monetary savings, specifically in terms of reduction of economic burden of the disease. Although the number of studies is still limited, the available data support a SLIT effect on sparing costs for respiratory allergy.