Synthesis and analgesic activity of some acetamide derivatives

In the present study, some acetamide derivatives were synthesized and their potential analgesic activities were investigated. N-(benzothiazol-2-yl)-2-[(1-substituted-1H-tetrazol-5-yl)thio]acetamide derivatives were obtained by the nucleophilic substitution reaction of 2-chloro-N-(benzothiazole-2-yl)acetamides with appropriate tetrazol-5-thioles. The chemical structures of the compounds were elucidated by IR, 1H-NMR, 13C-NMR and FAB?-MS spectral data and elemental analyses. The prepared compounds were investigated for their potential analgesic properties against thermal, mechanical and chemical nociceptive stimuli using hot-plate, tail-clip and acetic acid-induced writhing tests, respectively. The assessment of motor coordination was carried out using Rota-Rod test. Tested compounds applied at 100 mg/kg doses caused significant decrease in acetic acid-induced writhing responses and increase in hot-plate and tail-clip latencies. None of the compounds exhibited destructive effect on motor coordination of the mice in Rota-Rod performance.     

Misperceptions in the trajectories of objects undergoing curvilinear motion

Trajectory perception is crucial in scene understanding and action. A variety of trajectory misperceptions have been reported in the literature. In this study, we quantify earlier observations that reported distortions in the perceived shape of bilinear trajectories and in the perceived positions of their deviation. Our results show that bilinear trajectories with deviation angles smaller than 90 deg are perceived smoothed while those with deviation angles larger than 90 degrees are perceived sharpened. The sharpening effect is weaker in magnitude than the smoothing effect. We also found a correlation between the distortion of perceived trajectories and the perceived shift of their deviation point. Finally, using a dual-task paradigm, we found that reducing attentional resources allocated to the moving target causes an increase in the perceived shift of the deviation point of the trajectory. We interpret these results in the context of interactions between motion and position systems.     

Remodeling of the human papillomavirus type 11 replication origin into discrete nucleoprotein particles and looped structures by the E2 protein

The human papillomavirus (HPV) DNA replication origin (ori) shares a common theme with many DNA control elements in having multiple binding sites for one or more proteins spaced over several hundreds of base pairs. The HPV type 11 ori spans 103 bp and contains three palindromic E2 binding sites (E2BS-2, E2BS-3, and E2BS-4) for the dimeric E2 ori binding protein. These sites are separated by 64 and 3 bp. E2BS-1 is located 288 bp upstream of E2BS-2 and is not required for efficient transient or cell-free replication. In this study, electron microscopy was used to visualize complexes of HPV-11 DNA ori bound by purified E2 protein. DNA containing only E2BS-2 showed a single E2 dimer bound. DNA containing E2BS-3 and E2BS-4 showed two side-by-side E2 dimers, while DNA containing E2BS-2, E2BS-3, and E2BS-4 exhibited a large disk/ring-shaped protein particle bound, indicating that the DNA had been remodeled into a discrete complex, likely containing an E2 hexamer. With all four binding sites present, up to 27% of the DNA molecules were arranged into loops by E2, the majority of which spanned E2BS-1 and one of the other three sites. Studies on the dependence of looping on salt, ATP, and DTT using full-length E2 and an E2 protein containing only the carboxyl-terminal DNA binding and protein dimerization domain suggest that looping is dependent on the N-terminal domain and factors that may affect the manner in which E2 scans DNA for binding sites. The role of these structures in the modeling and regulation of the HPV-11 ori is discussed.     

Agonist-induced force enhancement: the role of isoforms and phosphorylation of the myosin-targeting subunit of myosin light chain phosphatase.

The magnitude of agonist-induced Ca(2+) sensitization of force is tissue-dependent, but an explanation for this diversity is unknown. Ca(2+) sensitization is thought to involve a G-protein-mediated inhibition of myosin light chain phosphatase activity by phosphorylation of the myosin-targeting subunit (MYPT). The MYPT has two isoforms that differ by a central insert, which lies near this phosphorylation site. Expression of MYPT isoforms is both developmentally regulated and tissue-specific. We hypothesized that the presence or absence of the central insert determines the magnitude of agonist-induced Ca(2+) sensitization. Throughout development, the chicken aorta exclusively expresses the splice-in MYPT isoform, and guanosine 5'-O-(thiotriphosphate) (GTPgammaS) produces a significant force enhancement. Early during development, the chicken gizzard expresses the splice-in MYPT isoform, and GTPgammaS produced a Ca(2+) sensitization. In the gizzard coincident with the shift in expression from the splice-in to splice-out MYPT isoform, GTPgammaS no longer produced force enhancement. In addition, adenosine 5'-O-(thiotriphosphate) (ATPgammaS) phosphorylated only adult gizzard tissue, the only tissue that did not demonstrate a Ca(2+) sensitization. These results suggest that the relative expression of splice-in/splice-out MYPT isoforms determines the magnitude of agonist-induced force enhancement and that MYPT phosphorylation is not required for Ca(2+) sensitization.     

Distinct apoptotic blocks mediate resistance to panHER inhibitors in HER2+ breast cancer cells

Despite the development of novel targeted therapies, de novo or acquired chemoresistance remains a significant factor for treatment failure in breast cancer therapeutics. Neratinib and dacomitinib are irreversible panHER inhibitors, which block their autophosphorylation and downstream signaling. Moreover, neratinib and dacomitinib have been shown to activate cell death in HER2-overexpressing cell lines. Here we showed that increased MCL1 and decreased BIM and PUMA mediated resistance to neratinib in ZR-75-30 and SKBR3 cells while increased BCL-XL and BCL-2 and decreased BIM and PUMA promoted neratinib resistance in BT474 cells. Cells were also cross-resistant to dacomitinib. BH3 profiles of HER2+ breast cancer cells efficiently predicted antiapoptotic protein dependence and development of resistance to panHER inhibitors. Reactivation of ERK1/2 was primarily responsible for acquired resistance in SKBR3 and ZR-75-30 cells. Adding specific ERK1/2 inhibitor SCH772984 to neratinib or dacomitinib led to increased apoptotic response in neratinib-resistant SKBR3 and ZR-75-30 cells, but we did not detect a similar response in neratinib-resistant BT474 cells. Accordingly, suppression of BCL-2/BCL-XL by ABT-737 was required in addition to ERK1/2 inhibition for neratinib- or dacomitinib-induced apoptosis in neratinib-resistant BT474 cells. Our results showed that different mitochondrial apoptotic blocks mediated acquired panHER inhibitor resistance in HER2+ breast cancer cell lines as well as highlighted the potential of BH3 profiling assay in prediction of panHER inhibitor resistance in breast cancer cells.     

Single-stage photofermentative biohydrogen production from sugar beet molasses by different purple non-sulfur bacteria

Bioprocess and Biosystems Engineering - Biohydrogen production via fermentative routes offers considerable advantages in waste recycling and sustainable energy production. This can be realized by...     

Time-dependent changes in the serum levels of prolactin, nesfatin-1 and ghrelin as a marker of epileptic attacks young male patients

A relationship between hormones and seizures has been reported in animals and humans. Therefore, the purpose of this study was to investigate the association between serum levels of prolactin, nesfatin-1 and ghrelin measured different times after a seizure or non-epileptic event and compared with controls. The study included a total of 70 subjects, and of whom 18 patients had secondary generalized epilepsy (SGE), 16 patients had primary generalized epilepsy (PGE), 16 patients exhibited paroxysmal event (psychogenic) and 20 healthy males were control subjects. The first sample was taken within 5 min of a seizure, with further samples taken after 1, 24, and 48 h so long as the patient did not exhibit further clinically observable seizures; blood samples were taken once from control subjects. Prolactin was measured immediately using TOSOH Bioscience hormone assays. Nesfatin-1 and ghrelin peptides were measured using a commercial immunoassay kit. Patients suffering from focal epilepsy with secondary generalization and primary generalized epilepsy presented with significantly higher levels of serum prolactin and nesfatin-1 and lower ghrelin levels 5 min, 1 and 24 h after a seizure than patients presenting with paroxysmal events (psychogenic) and control subjects; the data were similar but not statistically significant after 48 h. The present study suggests that increased serum prolactin and nesfatin-1 concentrations, decreased ghrelin concentrations could be used as markers to identify patients that have suffered a recent epileptic seizure or other paroxysmal event (psychogenic).     

Biomarker-guided sequential targeted therapies to overcome therapy resistance in rapidly evolving highly aggressive mammary tumors

Combinatorial targeted therapies are more effective in treating cancer by blocking by-pass mechanisms or inducing synthetic lethality. However, their clinical application is hampered by resistance and toxicity. To meet this important challenge, we developed and tested a novel concept of biomarker-guided sequential applications of various targeted therapies using ErbB2-overexpressing/PTEN-low, highly aggressive breast cancer as our model. Strikingly, sustained activation of ErbB2 and downstream pathways drives trastuzumab resistance in both PTEN-low/trastuzumab-resistant breast cancers from patients and mammary tumors with intratumoral heterogeneity from genetically-engineered mice. Although lapatinib initially inhibited trastuzumab-resistant mouse tumors, tumors by-passed the inhibition by activating the PI3K/mTOR signaling network as shown by the quantitative protein arrays. Interestingly, activation of the mTOR pathway was also observed in neoadjuvant lapatinib-treated patients manifesting lapatinib resistance. Trastuzumab + lapatinib resistance was effectively overcome by sequential application of a PI3K/mTOR dual kinase inhibitor (BEZ235) with no significant toxicity. However, our p-RTK array analysis demonstrated that BEZ235 treatment led to increased ErbB2 expression and phosphorylation in genetically-engineered mouse tumors and in 3-D, but not 2-D, culture, leading to BEZ235 resistance. Mechanistically, we identified ErbB2 protein stabilization and activation as a novel mechanism of BEZ235 resistance, which was reversed by subsequent treatment with lapatinib + BEZ235 combination. Remarkably, this sequential application of targeted therapies guided by biomarker changes in the tumors rapidly evolving resistance doubled the life-span of mice bearing exceedingly aggressive tumors. This fundamentally novel approach of using targeted therapies in a sequential order can effectively target and reprogram the signaling networks in cancers evolving resistance during treatment.