Development of optical biosensor technologies for cardiac troponin recognition

Acute myocardial infarction (AMI) is the leading cause of death among cardiovascular diseases. Among the numerous attempts to develop coronary marker concepts into clinical strategies, cardiac troponin is known as a specific marker for coronary events. The cardiac troponin concentration level in blood has been shown to rise rapidly for 4–10 days after onset of AMI, making it an attractive approach for a long diagnosis window for detection. The extremely low clinical sensing range of cardiac troponin levels consequently makes the methods of detection highly sensitive. In this review, by taking into consideration optical methods applied for cardiac troponin detection, we discuss the most commonly used methods of optical immunosensing and provide an overview of the various diagnostic cardiac troponin immunosensors that have been employed for determination of cardiac troponin over the last several years.     

Assessing predicted HIV-1 replicative capacity in a clinical setting

HIV-1 replicative capacity (RC) provides a measure of within-host fitness and is determined in the context of phenotypic drug resistance testing. However it is unclear how these in-vitro measurements relate to in-vivo processes. Here we assess RCs in a clinical setting by combining a previously published machine-learning tool, which predicts RC values from partial pol sequences with genotypic and clinical data from the Swiss HIV Cohort Study. The machine-learning tool is based on a training set consisting of 65000 RC measurements paired with their corresponding partial pol sequences. We find that predicted RC values (pRCs) correlate significantly with the virus load measured in 2073 infected but drug na?ve individuals. Furthermore, we find that, for 53 pairs of sequences, each pair sampled in the same infected individual, the pRC was significantly higher for the sequence sampled later in the infection and that the increase in pRC was also significantly correlated with the increase in plasma viral load and with the length of the time-interval between the sampling points. These findings indicate that selection within a patient favors the evolution of higher replicative capacities and that these in-vitro fitness measures are indicative of in-vivo HIV virus load.     

Synthesis and biological evaluation of 2-substituted-4-(3′,4′,5′-trimethoxyphenyl)-5-aryl thiazoles as anticancer agents

Antitumor agents that bind to tubulin and disrupt microtubule dynamics have attracted considerable attention in the last few years. To extend our knowledge of the thiazole ring as a suitable mimic for the cis-olefin present in combretastatin A-4, we fixed the 3,4,5-trimethoxyphenyl at the C4-position of the thiazole core. We found that the substituents at the C2- and C5-positions had a profound effect on antiproliferative activity. Comparing compounds with the same substituents at the C5-position of the thiazole ring, the moiety at the C2-position influenced antiproliferative activities, with the order of potency being NHCH₃ > Me ? N(CH₃)₂. The N-methylamino substituent significantly improved antiproliferative activity on MCF-7 cells with respect to C2-amino counterparts. Increasing steric bulk at the C2-position from N-methylamino to N,N-dimethylamino caused a 1–2 log decrease in activity. The 2-N-methylamino thiazole derivatives 3b, 3d and 3e were the most active compounds as antiproliferative agents, with IC₅₀ values from low micromolar to single digit nanomolar, and, in addition, they are also active on multidrug-resistant cell lines over-expressing P-glycoprotein. Antiproliferative activity was probably caused by the compounds binding to the colchicines site of tubulin polymerization and disrupting microtubule dynamics. Moreover, the most active compound 3e induced apoptosis through the activation of caspase-2, -3 and -8, but 3e did not cause mitochondrial depolarization.     

Prostaglandin-E2 is produced by adult human epidermal melanocytes in response to UVB in a melanogenesis-independent manner

Excessive ultraviolet radiation (UVR) exposure induces erythema, mediated in part by prostaglandin-E₂ (PGE₂). While keratinocytes are a major PGE₂ source, epidermal melanocytes (EM) also express PGE₂-production machinery. It is unclear whether EM-produced PGE₂ contributes to UVR-induced skin inflammation, and whether this is correlated with melanogenesis. Epidermal melanocytes were cultured from skin phototype-1 and -4 donors, followed by assessment of PGE₂ production and melanogenesis. Epidermal melanocytes expressed cytoplasmic phospholipase-A₂, cyclooxygenase-1, cytoplasmic prostaglandin-E synthase and microsomal prostaglandin-E synthase-1, -2. Epidermal melanocytes produced PGE₂ under basal conditions, which increased further after arachidonic acid stimulation. Epidermal melanocytes expressed cyclooxygenase-2 (COX-2) mRNA and a selective COX-2 inhibitor (NS-398) reduced PGE₂ production. Ultraviolet B-induced PGE₂ production was positively correlated with skin phototype-1, despite variability between individual EM donors. By contrast, there was no correlation between PGE₂ production by EM and their melanogenic status. Thus, EM may contribute to UVR-induced erythema, with role of donor skin phototype more important than their melanogenic status.     

Identification of Tannerella forsythia antigens specifically expressed in patients with periodontal disease

Molecular pathogenesis of Tannerella forsythia, a putative periodontal pathogen, has not yet been adequately elucidated due to limited information on its virulence factors. Here, identification of in vivo expressed antigens of T. forsythia is reported using in vivo-induced antigen technology (IVIAT). Among 13 000 recombinant clones screened, 16 positive clones were identified that reacted reproducibly with sera obtained from patients with periodontal disease. DNA sequences from 12 of these in vivo-induced genes were determined. IVIAT-identified protein antigens of T. forsythia include: BspA, a well-defined virulence factor of T. forsythia; enzymes involved in housekeeping functions (tRNA synthetases, glycine hydroxymethyltransferase, and glucoside glucohydrolase); enzymes implicated in tissue destruction (dipeptidyl peptidase IV); a DNA mismatch repair protein; and putative outer membrane proteins of unknown function. The in vivo gene expression of these IVIAT-identified antigens was confirmed by a quantitative real-time PCR analysis. This is, to the best of the authors' knowledge, the first report using IVIAT in T. forsythia. It is anticipated that detailed analysis of the in vivo-induced genes identified by IVIAT in this study will lead to a better understanding of the molecular mechanisms mediating periodontal infection by T. forsythia.     

Oral poliovirus vaccine in management of recurrent aphthous stomatitis

Oral poliovirus vaccine (OPV) is reported to be effective in treatment of recurrent herpes simplex (RHS). According to our observation during recent years, OPV was not only effective in management of RHS but also in some patients with concomitant recurrent aphthous stomatitis (RAS) reducing its severity and frequency. The purpose of this study was to evaluate the efficacy of OPV in the management of RAS. In a longitudinal, case--control study 48 patients with RAS were recruited. Twenty patients received OPV and 28 patients received placebo. OPV was administered in a dose of 4 drops at monthly intervals for 3 months to the study group while the control group received placebo. The results were registered in 3 months after the last dose. Eight cases (40%) in the OPV group showed significant reduction in the duration of the ulcers, while no change was seen in the control group (P = 0.048). The frequency of recurrence of RAS was reduced in 13 cases (65%) in the OPV group, and in 6 cases (21.4%) of the placebo group (P = 0.006). The severity of attacks was reduced in 12 cases (60%) in the OPV group and in 4 cases (14.3%) in the placebo group (P = 0.008). In conclusion OPV appeared to be effective in the management of RAS.