Effect of 1-(1-Naphtylmethyl)-piperazine,an Efflux Pump Inhibitor,on Antimicrobial Drug Susceptibilities of Clinical <Emphasis Type="Italic">Acinetobacter baumannii</Emphasis> Isolates

In this study, the effects of 1-(1-naphtylmethyl)-piperazine (NMP), an efflux pump inhibitor, on antimicrobial drug susceptibilities of 42 clinical Acinetobacter baumannii isolates were investigated by the disc diffusion method. The inhibition zone diameters of antibiotic discs were tested in the presence and absence of NMP and then these zone diameters were compared. Presence of NMP restored ciprofloxacin susceptibility in 15 intermediate and 2 resistant isolates. One ciprofloxacin resistant isolate became intermediate in the presence of NMP. One isolate resistant to gentamicin became intermediate with NMP. Interestingly, one isolate susceptible to meropenem became resistant in the presence of NMP. Although NMP increased the inhibition zone diameters of some of the tested antibiotics against the resistant isolates, the increase was not enough to restore susceptibility. In conclusion, the presence of NMP increases the zone diameters of ciprofloxacin and levofloxacin. Intermediate strains become susceptible but the resistant isolates do not.     

Characterization of humic materials extracted from hazelnut husk and hazelnut husk amended soils

This study was carried out to determine effects of composted hazelnut husk (CHH) on some chemical properties of soil and soil humic acid (HA). Compost application increases organic matter (OM) content of the soil considerably, OM value of 3.18% became 3.89% in 3 years time interval. Before application of compost, the soil pH was found to be 5.37, while after compost application it became 5.61. FTIR characteristics of humic acid/humic acid-like materials extracted from the original hazelnut husk, composted hazelnut husk and composted hazelnut husk amended soil have been investigated. C and O content of humic acid-like/humic acid materials were in the range of 41.4–50.8% and 37.8–50.5%, respectively. The N content of the humic acid/humic acid-like materials are in the expected range for humic materials which is 2–6%. Comparison of FTIR spectra of hazelnut husk and composted hazelnut husk humic acid-like fractions shows that both exhibit similar but not identical series of IR bands indicating the presence of the same functional groups in both samples. The only difference in the spectra seemed to be a decrement in the peak intensities of composted sample compared to uncomposted one. The similar differentiation of the intensities of IR bands of compost applied soil sample has also been observed. The FTIR spectral results show that the characteristics of composted material tend to become similar to that of soil humic acids characteristics in time.     

Optimization of inoculum density to support root growth and secondary metabolite accumulation in root cultures of endangered Gentiana species: Gentiana lutea and Gentiana boissieri

In Vitro Cellular & Developmental Biology - Plant - Gentiana species belonging to the Gentianaceae family are medicinal plants rich in glycosides and phenolics. Gentiana lutea L. is a highly...     

Plasmonic-based platforms for diagnosis of infectious diseases at the point-of-care

Infectious diseases such as HIV-1/AIDS, tuberculosis (TB), hepatitis B (HBV), and malaria still exert a tremendous health burden on the developing world, requiring rapid, simple and inexpensive diagnostics for on-site diagnosis and treatment monitoring. However, traditional diagnostic methods such as nucleic acid tests (NATs) and enzyme linked immunosorbent assays (ELISA) cannot be readily implemented in point-of-care (POC) settings. Recently, plasmonic-based biosensors have emerged, offering an attractive solution to manage infectious diseases in the developing world since they can achieve rapid, real-time and label-free detection of various pathogenic biomarkers. Via the principle of plasmonic-based optical detection, a variety of biosensing technologies such as surface plasmon resonance (SPR), localized surface plasmon resonance (LSPR), colorimetric plasmonic assays, and surface enhanced Raman spectroscopy (SERS) have emerged for early diagnosis of HIV-1, TB, HBV and malaria. Similarly, plasmonic-based colorimetric assays have also been developed with the capability of multiplexing and cellphone integration, which is well suited for POC testing in the developing world. Herein, we present a comprehensive review on recent advances in surface chemistry, substrate fabrication, and microfluidic integration for the development of plasmonic-based biosensors, aiming at rapid management of infectious diseases at the POC, and thus improving global health.     

Altitudinal genetic and morphometric variation among populations of Culex theileri Theobald (Diptera: Culicidae) from northeastern Turkey

Enviromental conditions, including such important climatic variables as temperature and precipitation, change with altitude; thus, elevation plays a significant role in determining population and community structure in a variety of organisms. Using single nucleotide polymorphisms (SNPs) and geometric morphometrics, nine populations of Culex theileri Theobald occurring in different ecological subregions at altitudes between 808-2,130 m in northeastern Turkey were compared. The wing size and shape data indicate that there are significant phenotypic differences among them, while Cx theileri populations are not genetically differentiated in the northeast part of Turkey. The size and shape variation analysis of wings showed that there is a positive correlation between wing (body) size/shape and altitude.     

Effects of fed-batch fermentation and pH profiles on nisin production in suspended-cell and biofilm reactors

A biofilm reactor not only shortens the lag phase of nisin production, but also enhances nisin production when combined with an appropriate pH profile. Due to the substrate inhibition that takes place at high levels of carbon source, fed-batch fermentation was proposed as a better alternative for nisin production. In this study, the combined effects of fed-batch fermentation and various pH profiles on nisin production in a biofilm reactor were evaluated. The tested pH profiles include 1) a constant pH profile at 6.8 (profile 1), 2) a constant pH profile with an autoacidification after 4 h (profile 2), and 3) a step-wise pH profile with pH adjustment every 2 h (profile 3). When profile 1 was applied, fed-batch fermentation enhanced nisin production for both suspended-cell (4,188 IU ml⁻¹) and biofilm (4,314 IU ml⁻¹) reactors, yielded 1.8- and 2.3-fold higher nisin titer than their respective batch fermentation. On the other hand, pH profiles that include periods of autoacidification (profiles 2 and 3) resulted in a significantly lower nisin production in fed-batch fermentation (2,494 and 1,861 IU ml⁻¹ for biofilm reactor using profile 2 and 3, respectively) due to toxicity of excess lactic acid produced during the fermentation. Overall, this study suggested that fed-batch fermentation can be successfully used to enhance nisin production for both suspended-cell and biofilm reactors.     

Dental pulp stem cells (DPSCs) increase prostate cancer cell proliferation and migration under in vitro conditions

Cancer as a multistep and complicated disease is regulated by several molecular and cellular events. Cancer treatment could be managed at the early stages when the tumor is confined in the tissue. However, disseminated cancer cells metastasize to other body parts and generate new tumors resulting in mortality. Mesenchymal stem cells (MSCs) are found in different body parts and helps adult tissue regeneration. The role of MSCs in cancer progression has emerged as one of the important aspects in cancer biology and is the aim of interest in recent years. In the current study, effects of Dental Pulp Stem Cells (DPSCs) on PC-3 prostate cancer cell proliferation and migration were conducted by cell proliferation, apoptosis, gene expression and cell migration analysis in vitro. Condition medium (CM) obtained from DPSCs increased cell proliferation of PC-3 cells and decreased apoptosis. Either administration of CM or trans well co-culture of DPSCs increased cell migration in scratch assay, confirmed by gene expression analysis of migratory genes including fibronectin, laminin and collagen type I (Col I). Furthermore, DPSCs participated in a self-organized structure with PC-3 cells in co-culture conditions. Overall, results indicated that DPSCs could promote PC-3 cancer cell proliferation and metastasis in co-culture conditions in vitro.     

The regulatory role of heparin on c-Met signaling in hepatocellular carcinoma cells

The role of heparin as an anticoagulant is well defined; however, its role in tumorigenesis and tumor progression is not clear yet. Some studies have shown that anticoagulant treatment in cancer patients improve overall survival, however, recent clinical trials have not shown a survival benefit in cancer patients receiving heparin treatment. In our previous studies we have shown the inhibitory effects of heparin on Hepatocyte Growth Factor (HGF)-induced invasion and migration in hepatocellular carcinoma (HCC) cells. In this study, we showed the differential effects of heparin on the behaviors of HCC cells based on the presence or absence of HGF. In the absence of HGF, heparin activated HGF/c-Met signaling and promoted motility and invasion in HCC cells. Heparin treatment led to c-Met receptor dimerization and activated c-Met signaling in an HGF independent manner. Heparin-induced c-Met activation increased migration and invasion through ERK1/2, early growth response factor 1 (EGR1) and Matrix Metalloproteinases (MMP) axis. Interestingly, heparin modestly decreased the proliferation of HCC cells by inhibiting activatory phosphorylation of Akt. The inhibition of c-Met signaling reversed heparin-induced increase in motility and invasion and, proliferation inhibition. Our study provides a new perspective into the role of heparin on c-Met signaling in HCC.