Monitoraggio ecografico dello pneumotorace nel paziente politraumatizzato ventilato: confronto con la tradizionale radiologia.

Il torace è stato sempre considerato un segmento corporeo difficilmente valutabile con gli ultrasuoni poiché l’aria impedisce la valutazione morfologica degli organi. Per tale motivo l’ecografia del polmone si è sviluppata recentemente dopo che alcuni studi osservazionali hanno mostrato la possibilità di analizzare per via ecografica numerose patologie polmonari, tra cui lo pneumotorace. Essa si propone ormai come il fonendoscopio dei nostri giorni che deve essere conosciuto da ogni medico poiché la medicina moderna richiede sempre maggior accuratezza. Questo rinnovato interesse è basato sul concetto del “paradosso del polmone”, fenomeno per cui quest' organo, poco esplorabile in condizioni normali, mostra invece significative finestre acustiche in caso di patologia. Il 60% dei politraumatizzati presenta lesioni del torace, importanti causa di mortalità e morbidità; la principale causa di politrauma è l'incidente stradale, responsabile generalmente di traumi toracici chiusi di cui un 20% mostra pneumotorace. Il gold standard per la diagnosi di pneumotorace è la TC torace anche senza mdc, in grado di identificare persino minime falde aeree e le eventuali patologie sottostanti come le bolle enfisematose. Radiologicamente la diagnosi è agevole solo per immagini acquisite in ortostatismo e al massimo espirio, in collassi polmonari tali da determinare uno spazio aereo radiolucente tra i foglietti pleurici La bassa accuratezza diagnostica della radiologia tradizionale per lo pneumotorace, specialmente se eseguita in un'unica proiezione a paziente supino con pnx piccolo e anteriore, è infatti ormai ampiamente documentata in letteratura (sensibilità 28-75%) rispetto a quella ecografica (sensibilità 92-98%). L'ecografia toracica si propone come valida integrazione alle due metodiche suddette riuscendo non solo a fornire vantaggi quali la ripetitibilità, il basso costo e l'esecuzione bedside nel paziente critico, ma anche a compensare la bassa accuratezza diagnostica della radiografia eseguita in una unica proiezione, a paziente supino con pneumotorace piccolo o anteriore. Questa fetta di pneumotoraci “occulti” è particolarmente importante nel paziente sottoposto a ventilazione meccanica a pressione positiva, soprattutto se il parenchima polmonare è già compromesso

Differential effects on membrane permeability and viability of human keratinocyte cells undergoing very low intensity megasonic fields

Among different therapeutic applications of Ultrasound (US), transient membrane sonoporation (SP) - a temporary, non-lethal porosity, mechanically induced in cell membranes through US exposure - represents a compelling opportunity towards an efficient and safe drug delivery. Nevertheless, progresses in this field have been limited by an insufficient understanding of the potential cytotoxic effects of US related to the failure of the cellular repair and to the possible activation of inflammatory pathway. In this framework we studied the in vitro effects of very low-intensity US on a human keratinocyte cell line, which represents an ideal model system of skin protective barrier cells which are the first to be involved during medical US treatments. Bioeffects linked to US application at 1 MHz varying the exposure parameters were investigated by fluorescence microscopy and fluorescence activated cell sorting. Our results indicate that keratinocytes undergoing low US doses can uptake drug model molecules with size and efficiency which depend on exposure parameters. According to sub-cavitation SP models, we have identified the range of doses triggering transient membrane SP, actually with negligible biological damage. By increasing US doses we observed a reduced cells viability and an inflammatory gene overexpression enlightening novel healthy relevant strategies

Size-exclusion chromatographic NMR of polymer mixtures

The use of chromatographic stationary phases or solvent modifiers to modulate diffusion properties in NMR experiments is now well established. Their use can be to improve resolution in the diffusion domain or to provide an insight into analyte–modifier interactions and, hence, the chromatography process. Here, we extend previous work using size-exclusion chromatographic sta- tionary phases to the investigation of polymer mixtures. We demonstrate that similar diffusion modulation behaviour is observed with a size-exclusion chromatographic stationary phase that can be understood in terms of size-exclusion behaviour

Assetto ormonale tiroideo in pazienti efficacemente rivascolarizzati per infarto miocardico acuto e sopraslivellamento del tratto ST.

un alterato assetto funzionale tiroideo, caratterizzato dalla presenza di una sindrome da bassa T3 (LT3S), rappresenta un reperto di frequente osservazione nei pazienti ricoverati presso i reparti di terapia intensiva per infarto miocardico acuto. Il significato di tale sindrome nel decorso della malattia non ? tuttavia finora ben chiarito

Association of the 894G>T polymorphism in the endothelial nitric oxide synthase gene with risk of acute myocardial infarction

Background: This study was designed to investigate the association of the 894G>T polymorphism in the eNOS gene with risk of acute myocardial infarction (AMI), extent of coronary artery disease (CAD) on coronary angiography, and in-hospital mortality after AMI. Methods: We studied 1602 consecutive patients who were enrolled in the GEMIG study. The control group was comprised by 727 individuals, who were randomly selected from the general adult population. Results: The prevalence of the Asp298 variant of eNOS was not found to be significantly and independently associated with risk of AMI (RR = 1.08, 95%CI = 0.77–1.51, P = 0.663), extent of CAD on angiography (OR = 1.18, 95%CI = 0.63–2.23, P = 0.605) and in-hospital mortality (RR = 1.08, 95%CI = 0.29–4.04, P = 0.908). Conclusion: In contrast to previous reports, homozygosity for the Asp298 variant of the 894G>T polymorphism in the eNOS gene was not found to be associated with risk of AMI, extent of CAD and in-hospital mortality after AM

Magnetic resonance and ultrasound contrast imaging of polymer-shelled microbubbles loaded with iron oxide nanoparticles

Dual-mode contrast agents (CAs) have great potential for improving diagnostics. However, the effectiveness of CAs is strictly related to both the solution adopted to merge the two agents into a single probe unit, and the ratio between the two agents. In this study, two dual-mode CAs for simultaneous magnetic resonance imaging (MRI) and ultrasound imaging (UI) were assessed. For this purpose, different densities of superparamagnetic iron oxide nanoparticles (SPIONs) were anchored to the external surface of polymer-shelled microbubbles (MBs) or were physically entrapped into the shell. In vitro static and dynamic experiments were carried out with a limited concentration of modified MBs (106 bubbles ml 121) by avoiding destruction during UI (performed at a peak pressure lower than 320 kPa) and by using a lowfield MRI system (with a magnetic flux density equal to 0.25 T). Under these conditions, different imaging techniques, set-up parameters and SPION densities were used to achieve satisfactory detection of the CAs by using both UI and MRI. However, when the SPION density was increased, the MRI contrast improved, whereas the UI contrast worsened due to the reduced elasticity of the MB shell. For both UI and MRI, MBs with externally anchored SPIONs provided better performance than MBs with SPIONs entrapped into the shell. In particular, a SPION density of 29% with respect to the mass of the MBs was successfully tested

Toward a Theranostic Approach for the Brain Tumor Toxicity Profile of Polymer-Shelled Microbubbles

The establishment of theranostic devices by combining multimodal real-time intraoperative imaging for brain tumor surgery with targeted drug delivery may provide therapeutic advantages for patients with malignant gliomas. Our group has recently developed a new generation of novel microbubbles (MBs), with an air core and a crosslinked poly(vinyl alcohol) shell, called PVA MBs. The PVA MB surface was engineered to support near-infrared (NIR) imaging with a fluorescence probe (C790) for the surgical microscope. The attachment to a cyclic pentapeptide containing the RGD sequence promotes active adhesion and direct targeting of endothelial tumor integrins. The conjugation of temozolomide (TMZ), an alkylating chemotherapy proven to be effective against malignant gliomas, provides a unique therapeutic advantage. The potential toxicity of this novel technology was assessed in rats by intravenous injections of two doses of naked MBs and MBs equipped with RGD for targeting tumor integrins, NIR fluorescence (CF790) for real-time visualization, and TMZ as a cytotoxic component, at two time points, 10 min and 7 days, for potential acute and chronic responses in rats [(1) MB, (2) MB-C790-RGD, and (3) MB-C790-RGD-TMZ]. No mortality occurred during the 7-day study period in any of the dosing groups. Decreased hemoglobin and hematocrit levels and increased triglyceride levels were noticed in the high-dose naked MBs and MBs-CF790-RGD groups. These findings may be associated with their enlarged spleen and liver, observed during necropsy. Histopathology examination in the high-dose animals showed the development of treatment-related changes seen mostly 7 days post dosing, consisting of granulomatous inflammation and foreign body reaction. Accordingly, we concluded that the low-dose tested items appeared to be safe. The results allow us to proceed with planning for an efficacy study before making the first attempt to use this technology in clinical practice