Multi-analyte responsive luminescent probes for the detection of biochemical targets in cell models / Wieloanalitowe, maloczasteczkowe sondy luminescencyjne do symultanicznego wykrywania kilku celów molekularnych w modelach komórkowych.

Luminescence has found wide application in biology, biotechnology and medicine. Particularly, fluorescent and bioluminescent probes allow visualization of molecular targets at the cellular level and even macromolecules or single small-molecule analytes. Among the most reliable tools for visualization of molecular targets are so-called responsive probes, which change the intensity and colour of the emitted signal after interaction with a molecular target. The majority of such probes allow detection of a single analyte. Meanwhile, most of the processes in the human body involve multiple elements. To better understand these mechanisms, it is possible to use several responsive probes simultaneously. However, this poses a risk of their different uptake by cells or different metabolism. In order to provide a more reliable response, so-called multi-analyte and multi-responsive probes are being developed. Examples of such probes will be discussed in the article, divided based on their response mechanism and detected changes within the cell.

Synthesis and Biological Evaluation of Lipophilic Nucleoside Analogues as Inhibitors of Aminoacyl-tRNA Synthetases.

Emerging antibiotic resistance in pathogenic bacteria and reduction of compounds in the existing antibiotics discovery pipeline is the most critical concern for healthcare professionals. A potential solution aims to explore new or existing targets/compounds. Inhibition of bacterial aminoacyl-tRNA synthetase (aaRSs) could be one such target for the development of antibiotics. The aaRSs are a group of enzymes that catalyze the transfer of an amino acid to their cognate tRNA and therefore play a pivotal role in translation. Thus, selective inhibition of these enzymes could be detrimental to microbes. The 5'-O-(N-(L-aminoacyl)) sulfamoyladenosines (aaSAs) are potent inhibitors of the respective aaRSs, however due to their polarity and charged nature they cannot cross the bacterial membranes. In this work, we increased the lipophilicity of these existing aaSAs in an effort to promote their penetration through the bacterial membrane. Two strategies were followed, either attaching a (permanent) alkyl moiety at the adenine ring via alkylation of the N6-position or introducing a lipophilic biodegradable prodrug moiety at the alpha-terminal amine, totaling eight new aaSA analogues. All synthesized compounds were evaluated in vitro using either a purified Escherichia coli aaRS enzyme or in presence of total cellular extract obtained from E. coli. The prodrugs showed comparable inhibitory activity to the parent aaSA analogues, indicating metabolic activation in cellular extracts, but had little effect on bacteria. During evaluation of the N6-alkylated compounds against different microbes, the N6-octyl containing congener 6b showed minimum inhibitory concentration (MIC) of 12.5 µM against Sarcina lutea while the dodecyl analogue 6c displayed MIC of 6.25 µM against Candida albicans.

Metastatic Calcinosis of Aortic Valve Secondary to Renal Failure Mimicking Infective Endocarditis.

End stage renal disease has a list of consequences, cardiovascular being the most common. Inefficient dialysis can cause significant deposition of calcium all over the body, including heart valves making heart function impaired. We illustrate a case of 38-year-old female with end stage renal disease on peritoneal dialysis. The patient had been complaining of pain and swelling of the right hand for the last few months and had been seen by hand surgeon and was admitted electively for the biopsy of hand lesions. Before her planned surgery, she developed severe shortness of breath. Urgent echocardiogram revealed severe aortic regurgitation and large vegetation on the aortic valve. Infective endocarditis was suspected but blood cultures were negative for any microorganism and the patient did not meet the Duke criteria. Because of her hemodynamic instability immediate mechanical valve replacement surgery was performed. The pathology report showed extensive calcification and myxoid degeneration. No infectious agent was found. Later on, biopsy of her hand lesions showed extensive calcification with macrophages and giant cells. No atypia or malignancy was identified. This is a rare case of the metastatic calcinosis of aortic valve secondary to renal failure mimicking aortic valve infective endocarditis.

Right Atrial Mass in a Patient With HIV and Hepatitis B: A Case Report.

A 41-year-old man presented to the emergency room for evaluation of substernal chest pain, shortness of breath and generalized failure to thrive. Patient had history of hepatitis B and HIV. During recent evaluation of hepatic mass, patient was found to have hepatocellular carcinoma on biopsy. Patient had no history of cirrhosis of the liver in the past. On Echocardiogram patient was noted to have a large mass filling the right atrial cavity. CT scan of abdomen, pelvis and chest showed a diffusely enlarged heterogeneously enhancing liver consistent with large hepatoma, with portal venous and hepatic vein thrombosis. Tumor thrombus extended through the hepatic veins and upper inferior vena cava into the right atrium. There was 6 cm greatest diameter enhancing mass in the right atrium. Patient had primary hepatocellular carcinoma with extensive invasion into vascular structures. His prognosis was poor and patient opted for palliative care only. In conclusion, patients with co-infection of HIV and Hepatitis B are at risk of developing hepatocellular carcinoma with extension into the right atrium and physicians managing these patients should have high suspicion of right atrial involvement with tumor extension and low threshold to order a screening echocardiogram.

Effectiveness of elective stenting of common carotid artery lesions in preventing stroke.

We report our experience with elective stenting of lesions only involving the origin and proximal common carotid arteries. In 37 patients (42 vessels), procedural success was 95% (40 of 42 vessels) with 2 minor strokes (4.70%) and no major strokes. Follow-up for a mean of 24 months showed 1 transient ischemic attack, 2 contralateral minor strokes, 1 cerebral hemorrhage associated with long-term warfarin therapy, and a 5.1% restenosis rate. This technique is an excellent alternative for treating proximal and ostial lesions of the common carotid artery.

Predictors of restenosis after successful carotid artery stenting.

This study was performed to determine the risk factors for restenosis after successful carotid stenting. Of 222 patients who underwent successful carotid stenting, 179 (81%) had a follow-up study (carotid ultrasound and/or angiogram). Restenosis rate was 6.7% (14 of 195) for vessels. By univariate analysis, restenosis rates were significantly different between men and women (4% vs 15.4%, p = 0.018) and age < or =75 versus >75 years (3.8% vs 16%, p = 0.013). By multivariate analysis, older age (odds ratio [OR] 1.107, p = 0.015), female sex (OR 3.519, p = 0.001), implantation of multiple stents (OR 2.363, p = 0.019), and postprocedural percent stenosis (OR 1.067, p = 0.054) were associated with increased incidence of restenosis.

Long-term clinical outcome after implantation of medium Palmaz (biliary) stents in very large native coronary arteries.

Intracoronary stenting has been shown to improve acute and long-term clinical results compared with coronary angioplasty. However, clinical outcome after medium Palmaz biliary (PB) stent implantation in very large native coronary arteries (> 4 mm in diameter) is unknown. This study evaluated restenosis and long-term clinical outcome after PB stenting in large native coronary arteries. Between June 1993 and December 1998, 55 patients with 56 lesions were treated with PB stents. Intracoronary stent deployment was successful in all 56 vessels attempted (100%). The mean stenosis was reduced from 65% +/- 10% to 4% +/- 14%. In 48 of the 56 vessels (86%), vessel size was greater than 4.0 mm in diameter and the mean reference vessel diameter was 4.73 +/- 0.7 mm after stenting. Angiographic success was achieved in 100%. Five patients had postprocedural cardiac enzyme elevation. There was no periprocedural death, emergency coronary artery bypass surgery, repeat target lesion revascularization, or acute stent thrombosis. Long-term clinical follow-up at mean of 28 +/- 15 months was obtained in 96% of the patients. Clinical restenosis rate occurred in 18% of ostial (6/34) and 0% of nonostial (0/22) lesions (P < 0.0001) with an overall clinical restenosis rate of 11%. Repeat angioplasty were performed in these six patients. There were three cardiac and three noncardiac deaths. The overall event-free survival at 1 and 3 years was 92% +/- 4% and 80% +/- 6%, respectively. PB stent implantation in very large native coronary arteries can be performed with a high degree of procedural success and low in-hospital complications. The long-term clinical outcome of patients undergoing PB stenting is associated with excellent event-free survival. However, stenting of ostial lesions remains as an important factor for restenosis even in very large coronary artery stenting.