Factors reducing omalizumab response in severe asthma.

BACKGROUND: Despite adding Omalizumab to conventional therapy, several severe asthmatics still show poor disease control. We investigated the factors that may affect a reduced Omalizumab response in a large population of severe asthmatics. METHODS: 340 patients were retrospectively evaluated. FEV1%, FVC%, Asthma Control Test (ACT), fractional exhaled nitric oxide (FENO), possible step-downs/step-ups of concomitant therapies, exacerbations, disease control levels, ICS doses and SABA use, observed at the end of treatment, were considered as a response to Omalizumab. RESULTS: Age was an independent risk factor for a reduced response concerning FEV1%, FVC%, ACT and for a lower asthma control. Obesity (vs normal weight) was a determinant condition for exacerbations (OR:3.114[1.509-6.424], p = 0.002), for a disease partial/no control (OR:2.665[1.064-6.680], p = 0.036), for excessive SABA use (OR:4.448[1.837-10.768], p = 0.002) and for an unchanged/increased level of concomitant asthma medications. Furthermore, obesity also reduced the response in FEV1 (ß = -6.981,p = 0.04), FVC (ß = -11.689,p = 0.014) and ACT (ß = -2.585, p = 0.027) and was associated with a higher FENO level (ß = 49.045,p = 0.040). Having at least one comorbidity was a risk factor for exacerbations (OR:1.383[1.128-1.697], p = 0.008) and for an ACT <20 (OR:2.410[1.071-3.690], p = 0.008). Specifically, chronic heart disease was associated with both a lower ACT and FVC% whereas gastroesophageal reflux with a partial/no asthma control. Nasal polyps were a predisposing factor leading both to exacerbations and to the use of higher inhaled corticosteroids doses. Moreover, smoking habits, pollen or dog/cat dander co-sensitizations may negatively influence Omalizumab response. CONCLUSION: Age, obesity, comorbidities, smoking habits, nasal polyps, allergic poly-sensitization might reduce Omalizumab effectiveness independently to other asthma-influencing factors.

Different skin prick test sensitization patterns do not influence the response to Omalizumab in severe asthma

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Puddle-Induced Resistance Oscillations in the Breakdown of the Graphene Quantum Hall Effect.

We report on the stability of the quantum Hall plateau in wide Hall bars made from a chemically gated graphene film grown on SiC. The ν=2 quantized plateau appears from fields B≃5 T and persists up to B≃80 T. At high current density, in the breakdown regime, the longitudinal resistance oscillates with a 1/B periodicity and an anomalous phase, which we relate to the presence of additional electron reservoirs. The high field experimental data suggest that these reservoirs induce a continuous increase of the carrier density up to the highest available magnetic field, thus enlarging the quantum plateaus. These in-plane inhomogeneities, in the form of high carrier density graphene pockets, modulate the quantum Hall effect breakdown and decrease the breakdown current.

Can patent foramen ovale affect rehabilitation? The uncommon association of platypnea-orthodeoxia syndrome and stroke.

Platypnea-orthodeoxia is a rare syndrome characterized by dyspnea and deoxygenation induced by a change to a sitting or standing from a recumbent position. It is the result of posturally accentuated intracardiac or pulmonary right-to-left shunt leading to arterial oxygen desaturation. Only few cases of platypnea-orthodeoxia syndrome are reported in the literature and the association between stroke and platypnea-orthodeoxia syndrome with evidence of patent foramen ovale is extremely rare. We describe the case of a 67-year-old female admitted to our Rehabilitation Unit for disabling basilar stroke due to paradoxical embolism from patent foramen ovale that during the first days of rehabilitation showed signs and symptoms of platypnea-orthodeoxia syndrome. To remove a life-threatening condition for the patient and in order to develop the normal rehabilitation project, that was stopped by the platypnea-orthodeoxia syndrome, the patient fastly underwent to percutaneous closure of patent foramen ovale. The stabilization of oxygen arterial saturation with postural changes and the disappearance of symptoms of POS allowed to develop the rehabilitation project with progressive neurological improvement.

Proposal for a graphene-based current nanoswitch.

We propose a graphene-based model nanoswitch for the control of current flow. The device is made up of a graphene nanoribbon with a longitudinal semi-infinite septum on its left side. The septum defines two terminals, where the current can be selectively directed by means of a high magnetic field and an adjustable potential step induced by a top gate. The device's working mechanism is based on the spatial chirality of currents in high magnetic fields and on the possibility of determining the electron-like or hole-like nature of the particles involved in transport by means of the adjustable potential step. The role of critical parameters such as the width of the ribbon and the presence of disorder are discussed.