Comparative analysis of the effects of chitosan and common plant growth regulators on <Emphasis Type="Italic">in vitro</Emphasis> propagation of <Emphasis Type="Italic">Ipomoea purpurea</Emphasis> (L.) Roth from nodal explants

This study aimed to evaluate the effects of partially N-acetylated chitosans with a degree of acetylation (DA) of 10% on in vitro propagation of an ornamental plant, Ipomoea purpurea, by emphasizing the importance of the degree of polymerization (DP) on in vitro plant development. The effects of either a chitosan oligomer mixture with a DP between 2 and 15 (5.0, 10.0, and 20.0 mg L^?1) or chitosan polymer with a DP of 70 were compared with commonly used cytokinins [6-benzylaminopurine (BAP) and kinetin (KIN) at 0.5, 1.0, 2.0, and 4.0 mg L^?1] and auxins [indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) at 0.25, 0.5, 1.0, and 2.0 mg L^?1]. The nodal explants used in this study were taken from donor plants obtained by germination of the seeds. The results indicated that all chitosan treatments had positive effects on the shoot induction, but only the oligomer mixture at 5 mg L^?1 gave the best results for mean shoot number, shoot length, and leaf number, compared to the other treatments and control. Also, all chitosan treatments increased mean number of roots and triggered adventitious root induction. However, root elongation was decreased in the presence of chitosan in the medium. The root elongation-inhibitory effects of chitosan become clearer in the presence of oligomer mixture. In general, chitosan had similar effects with tested cytokinins rather than auxins. The results of this study suggested that the application of chitosan oligomers—rather than polymers—can be an eco-friendly and effective alternative to synthetic cytokinins in horticulture.     

Xanthine biosensor based on XO/AuNP/PtNP/MWCNT hybrid nanocomposite modified GCPE

A new xanthine (X) biosensors based on a hybrid nanocomposite containing multi-walled carbon nanotubes (MWCNT), Pt nanoparticles (PtNP) and gold nanoparticle (AuNP) was presented. X biosensor was fabricated by dropping AuNP/PtNP/MWCNT onto xanthine oxidase (XO) modified glassy carbon paste electrode (GCPE). Resulted XO/AuNP/PtNP/MWCNT/GCPE biosensor showed two linearity between 2.0 and 50 µM and 0.25 and 6.0 mM for X. RSD value was calculated as 2.46 (n = 5). Finally, the biosensor was applied to the X detection in synthetic serum samples and good recovery value was obtained.     

Bee visitors of <Emphasis Type="Italic">Centaurea solstitialis</Emphasis> L. (Asteraceae) in an urban environment in northwestern Turkey

Information on the pollination ecology and floral visitors of the noxious weed Centaurea solstitialis is available for several populations in its invasive range, but limited information is available in its native range, with most studies conducted on the Greek island of Lesvos. Herein, we document the visitation pattern of bees and explore the relationship of bee body size and nectar availability in weedy populations of C. solstitialis from an urban environment within its native range in northwestern Turkey. Studies were conducted at patches of C. solstitialis in abandoned lots at the Uluda? University near the city of Bursa. A total of 41 species, including honey bees, belonging to five families and 19 genera were recorded. Small megachilid and halictid bee species were the most common visitors. Average nectar standing crop volume per floret was low (0.003–0.117 μL) and did not significantly vary throughout the day. Average bee head width significantly correlated with average nectar standing crop volume but did not significantly change throughout the day. Analyses of pollen loads as well as direct observations of bee foraging behavior indicate that a large number of bees visit C. solstitialis, primarily in search of nectar while carrying a large percentage of pollen grains of this plant species on their bodies. These results are similar to previous observations on a non-weedy population of C. solstitialis from the island of Lesvos.     

Secretion of fatty acid binding protein aP2 from adipocytes through a nonclassical pathway in response to adipocyte lipase activity

Adipocyte fatty acid binding protein 4, aP2, contributes to the pathogenesis of several common diseases including type 2 diabetes, atherosclerosis, fatty liver disease, asthma, and cancer. Although the biological functions of aP2 have classically been attributed to its intracellular action, recent studies demonstrated that aP2 acts as an adipokine to regulate systemic metabolism. However, the mechanism and regulation of aP2 secretion remain unknown. Here, we demonstrate a specific role for lipase activity in aP2 secretion from adipocytes in vitro and ex vivo. Our results show that chemical inhibition of lipase activity, genetic deficiency of adipose triglyceride lipase and, to a lesser extent, hormone-sensitive lipase blocked aP2 secretion from adipocytes. Increased lipolysis and lipid availability also contributed to aP2 release as determined in perilipin1-deficient adipose tissue explants ex vivo and upon treatment with lipids in vivo and in vitro. In addition, we identify a nonclassical route for aP2 secretion in exosome-like vesicles and show that aP2 is recruited to this pathway upon stimulation of lipolysis. Given the effect of circulating aP2 on glucose metabolism, these data support that targeting aP2 or the lipolysis-dependent secretory pathway may present novel mechanistic and translational opportunities in metabolic disease.     

Derivation,characterization and expansion of fetal chondrocytes on different microcarriers

Fetal chondrocytes (FCs) have recently been identified as an alternative cell source for cartilage tissue engineering applications because of their partially chondrogenically differentiated phenotype and developmental plasticity. In this study, chondrocytes derived from fetal bovine cartilage were characterized and then cultured on commercially available Cytodex-1 and Biosilon microcarriers and thermosensitive poly(hydroxyethylmethacrylate)-poly(N-isopropylacrylamide) (PHEMA-PNIPAAm) beads produced by us. Growth kinetics of FCs were estimated by means of specific growth rate and metabolic activity assay. Cell detachment from thermosensitive microcarriers was induced by cold treatment at 4 °C for 20 min or enzymatic treatment was applied for the detachment of cells from Cytodex-1 and Biosilon. Although attachment efficiency and proliferation of FCs on PHEMA-PNIPAAm beads were lower than that of commercial Cytodex-1 and Biosilon microcarriers, these beads also supported growth of FCs. Detached cells from thermosensitive beads by cold induction exhibited a normal proliferative activity. Our results indicated that Cytodex-1 microcarrier was the most suitable material for the production of FCs in high capacity, however, ‘thermosensitive microcarrier model’ could be considered as an attractive solution to the process scale up for cartilage tissue engineering by improving surface characteristics of PHEMA-PNIPAAm beads.     

Hsa-miR-584-5p as a novel candidate biomarker in Turkish men with severe coronary artery disease

Molecular Biology Reports - Coronary artery disease (CAD) is still the preliminary cause of mortality and morbidity in the developed world. Identification of novel predictive and therapeutic...