Silica nanoparticles for cell imaging and intracellular sensing.

There is increasing interest in the use of nanoparticles (NPs) for biomedical applications. In particular, nanobiophotonic approaches using fluorescence offers the potential of high sensitivity and selectivity in applications such as cell imaging and intracellular sensing. In this review, we focus primarily on the use of fluorescent silica NPs for these applications and, in so doing, aim to enhance and complement the key recent review articles on these topics. We summarize the main synthetic approaches, namely the Stöber and microemulsion processes, and, in this context, we deal with issues in relation to both covalent and physical incorporation of different types of dyes in the particles. The important issue of NP functionalization for conjugation to biomolecules is discussed and strategies published in the recent literature are highlighted and evaluated. We cite recent examples of the use of fluorescent silica NPs for cell imaging in the areas of cancer, stem cell and infectious disease research, and we review the current literature on the use of silica NPs for intracellular sensing of oxygen, pH and ionic species. We include a short final section which seeks to identify the main challenges and obstacles in relation to the potential widespread use of these particles for in vivo diagnostics and therapeutics.

Ruptured aneurysm of the sinus of Valsalva. Clinical review, treatment results.

Five patients were operated on because of ruptured aneurysm of the sinus of Valsalva. In the cases with no concomitant VSD the surgical access from the aorta was used. The aorta was opened and the Fogarty catheter was introduced to the fistula. The "wind sock" of the aneurysm was pulled back to the aorta and excised. The opening was closed with double-line pledgetted polypropylene sutures. In severe aortic incompetence mechanical prostheses were implanted. One patient had bacterial endocarditis with reopening of the fistula and aortic valve incompetence that required reoperation. All patients are in a good clinical state. We recommend the use of Dacron patches even in small aneurysms to avoid re-opening of the fistula.

[Silent myocardial ischemia before and after revascularization]. / Nieme niedokrwienie miesnia serca przed i po rewaskularyzacji.

In 82 patients with unstable ischemic heart disease (IHD) before and after revascularisation (percutaneous transluminal coronary angioplasty-PTCA-in 11 patients and coronary artery bypass graft-CABG-in 71 patients) silent ischemia incidence was observed. In these patients before and after operation election fraction (EF) and wall motion score index (IK) were compared echocardiographically as well as physical ability according to Bruce protocol in treadmill exercise test. Data (EF and IK and exercise test) before and after operation didn't change significantly. Silent ischemia was directed before operation in 17 patients (21.8%) and in 15 patients (19.4%) one month after those procedures.

[Metastatic neoplasms of the heart]. / Nowotwory przerzutowe serca.

Two cases are presented of metastatic neoplasm of the heart easy for echocardiographic diagnosis. One infiltrated the pericardium with encapsulated fluid (visible also on X-ray), and the other was associated with filling of the right atrial lumen.

Intracellular pH-sensing using core/shell silica nanoparticles.

An in-depth understanding of biochemical processes occurring within biological systems is key for early diagnosis of disease and identification of appropriate treatments. Nanobiophotonics offers huge potential benefits for intracellular diagnostics and therapeutics. Intracellular sensing using fluorescent nanoparticles is a potentially useful tool for real-time, in vivo monitoring of important cellular analytes. This work is focused on synthesis of optical chemical nanosensors for the quantitative analysis of pH inside living cells. The structure of the nanosensor comprises a biofriendly silica matrix with co-encapsulated Texas Red, acting as a reference dye, and pH-sensitive fluorescein isothiocyanate enabling ratiometric quantitative environmental detection. In order to obtain silica-based nanoparticles -70 nm in size, a modified sol-gel-based Stöber method was employed. The potential of these nanosensors for intracellular pH monitoring is demonstrated inside a live human embryonic kidney cell line whereby a significant change in fluorescence is observed when the cell pH is switched from acidic to basic. High loading efficiencies of nanoparticles into the cells is seen, with little effect on cell morphology even following extended nanoparticle exposure (up to 72 h). Nanoparticle incubation time and the fast response of the nanosensor (-2 s) make it a very powerful tool in monitoring the processes occurring within the cytosol.

[Dissecting aneurysm of the ascending aorta as a late complication of the treatment of acquired defects of the aortic and mitral valves]. / Tetniak rzekomy aorty wstepujacej jako pózne powiklanie w przebiegu pooperacyjnego leczenia wady nabytej zastawki aortalnej i mitralnej.

A diffuse aneurysm of the ascending aorta was observed five months after prosthetic valve implantation in to mitral and aortic orifices because of the acquired valvular heart disease. The main factor predisposing to the formation of a false aneurysm was an infection of the endocardium and ascending aortal wall which were observed previously during cardiac surgery. The diagnosis, based on the clinical symptoms and non-invasive investigations, was later confirmed with aortography and intra-operatively.

[Congestive cardiomyopathy after a 10-year observation]. / Kardiomiopatia zastoinowa w 10-letniej obserwacji.

A progress in the Polish cardiosurgery promising survival has led to the analysis of patients with congestive cardiomyopathy diagnosed with non-invasive techniques. The study involved 44 patients treated at the III Department of Cardiology in Katowice-Ochojec in 1980-1989. Sixty six percent of these patients were men. Etiology remained unknown in half of them, suggesting the primary cardiomyopathy (group I). As a cause of the secondary cardiomyopathy (group II) infections were considered (bacterial, fungal, and tuberculous), systemic diseases, and ischemic heart disease. Clinical status and results of all non-invasive diagnostic procedures performed since the beginning of therapy to the end of 1989 were analysed. Ultimate examination were performed at the Voivodeship Cardiologic Out-patient Clinic. Dynamics of the disease and effectiveness of the treatment were evaluated. In case of death its direct cause was sought. All results were compared in both groups.

[A case of isolated, corrected transposition of great arteries diagnosed with non-invasive techniques]. / Przypadek odosobnionego skorygowanego przelozenia wielkich pni tetniczych rozpoznanego metodami nieinwazyjnymi.

A case of a 34-year female patient with the isolated transposition of the great arterial trunks and mild atrioventricular (tricuspid) valve insufficiency is presented. The disease was diagnosed with non-invasive technique, particularly echocardiography. Cardiac disorders being usually concomitant with this syndrome (interventricular leak, pulmonary arterial wedge stenosis etc.) have been excluded by the aid of the contrast echographic technique and Doppler technique. The results of electrocardiographic records, which are usually helpful in the diagnosis of this abnormality have been completely useless in this case due to atypical ventricular depolarization vector pattern (QS complex in V1-V6 leads).