Detection of Vero Cells Infected with Herpes Simplex Types 1 and 2 and Varicella Zoster Viruses Using Raman Spectroscopy and Advanced Statistical Methods

Of the eight members of the herpes family of viruses, HSV1, HSV2, and varicella zoster are the most common and are mainly involved in cutaneous disorders. These viruses usually are not life-threatening, but in some cases they might cause serious infections to the eyes and the brain that can lead to blindness and possibly death. An effective drug (acyclovir and its derivatives) is available against these viruses. Therefore, early detection and identification of these viral infections is highly important for an effective treatment. Raman spectroscopy, which has been widely used in the past years in medicine and biology, was used as a powerful spectroscopic tool for the detection and identification of these viral infections in cell culture, due to its sensitivity, rapidity and reliability. Our results showed that it was possible to differentiate, with a 97% identification success rate, the uninfected Vero cells that served as a control, from the Vero cells that were infected with HSV-1, HSV-2, and VZV. For that, linear discriminant analysis (LDA) was performed on the Raman spectra after principal component analysis (PCA) with a leave one out (LOO) approach. Raman spectroscopy in tandem with PCA and LDA enable to differentiate among the different herpes viral infections of Vero cells in time span of few minutes with high accuracy rate. Understanding cell molecular changes due to herpes viral infections using Raman spectroscopy may help in early detection and effective treatment.     

Zinc Intake and Risk of Prostate Cancer: Case-Control Study and Meta-Analysis

Zinc is an essential dietary element that has been implicated in the pathogenesis of prostate cancer, a cancer that disproportionately affects men of African descent. Studies assessing the association of zinc intake and prostate cancer have yielded inconsistent results. Furthermore, very little is known about the relationship between zinc intake and prostate cancer among African Americans. We examined the association between self-reported zinc intake and prostate cancer in a hospital-based case-control study of African Americans. We then compared our results with previous studies by performing a meta-analysis to summarize the evidence regarding the association between zinc and prostate cancer. Newly diagnosed African American men with histologically confirmed prostate cancer (n = 127) and controls (n = 81) were recruited from an urban academic urology clinic in Washington, DC. Controls had higher zinc intake, with a mean of 14 mg/day versus 11 mg/day for cases. We observed a non-significant, non-linear increase in prostate cancer when comparing tertiles of zinc intake (OR _{<6.5 vs 6.5–12.5mg/day} 1.8, 95% CI: 0.6,5.6; OR _{<6.5 vs >12.5mg/day} 1.3, 95% CI: 0.2,6.5). The pooled estimate from 17 studies (including 3 cohorts, 2 nested case-control, 11 case-control studies, and 1 randomized clinical trial, with a total of 111,199 participants and 11,689 cases of prostate cancer) was 1.07_{hi vs lo} 95% CI: 0.98–1.16. Using a dose-response meta-analysis, we observed a non-linear trend in the relationship between zinc intake and prostate cancer (p for nonlinearity = 0.0022). This is the first study to examine the relationship between zinc intake in black men and risk of prostate cancer and systematically evaluate available epidemiologic evidence about the magnitude of the relationship between zinc intake and prostate cancer. Despite of the lower intake of zinc by prostate cancer patients, our meta-analysis indicated that there is no evidence for an association between zinc intake and prostate cancer.     

Improved heterologous production of the nonribosomal peptide‐polyketide siderophore yersiniabactin through metabolic engineering and induction optimization

Biosynthesis of complex natural products like polyketides and nonribosomal peptides using Escherichia coli as a heterologous host provides an opportunity to access these molecules. The value in doing so stems from the fact that many compounds hold some therapeutic or other beneficial property and their original production hosts are intractable for a variety of reasons. In this work, metabolic engineering and induction variable optimization were used to increase production of the polyketide‐nonribosomal peptide compound yersiniabactin, a siderophore that has been utilized to selectively remove metals from various solid and aqueous samples. Specifically, several precursor substrate support pathways were altered through gene expression and exogenous supplementation in order to boost production of the final compound. The gene expression induction process was also analyzed to identify the temperatures and inducer concentrations resulting in highest final production levels. When combined, yersiniabactin production was extended to ～175 mg L^?1. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1412–1417, 2016     

Design and characterization of electrochemical dopamine–aptamer as convenient and integrated sensing platform

Here, an ultrasensitive label-free electrochemical aptasensor was developed for dopamine (DA) detection. Construction of the aptasensor was carried out by electrodeposition of gold–platinum nanoparticles (Au–PtNPs) on glassy carbon (GC) electrode modified with acid-oxidized carbon nanotubes (CNTs–COOH). A designed complementary amine-capped capture probe (ssDNA1) was immobilized at the surface of PtNPs/CNTs–COOH/GC electrode through the covalent amide bonds formed by the carboxyl groups on the nanotubes and the amino groups on the oligonucleotides. DA-specific aptamer was attached onto the electrode surface through hybridization with the ssDNA1. Methylene blue (MB) was used as an electrochemical indicator that was intercalated into the aptamer through the specific interaction with its guanine bases. In the presence of DA, the interaction between aptamer and DA displaced the MB from the electrode surface, rendering a lowered electrochemical signal attributed to a decreased amount of adsorbed MB. This phenomenon can be applied for DA detection. The peak current of probe (MB) linearly decreased over a DA concentration range of 1–30 nM with a detection limit of 0.22 nM.     

Spectrofluorimetric determination of thioridazine and flupentixol in dosage forms; application to content uniformity test

A reliable, sensitive, cheap and non‐extractive spectrofluorimetric method has been developed and validated for determination of thioridazine and flupentixol based on ternary complex formation with eosin and lead(II) in the presence of methylcellulose as surfactant at pH 3.2. Under the optimum conditions, the quantitative quenching effect of investigated drugs on the native fluorescence of eosin has been investigated. The quenching of the eosin fluorescence was measured at 517 nm after excitation at 462 nm. The different experimental parameters affecting the development and stability of the reaction products were carefully studied and optimized, and the results were satisfactory. The calibration plots were constructed over the range of 0.5–3.0 µg mL^?1. The developed method was successfully applied for determination of investigated drugs in commercial tablets without interference from common excipients. It was further applied for content uniformity testing of flupentixol in its tablets. Statistical comparisons of the results with those of the reference methods revealed excellent agreement and indicated no significant difference in accuracy and precision. Copyright © 2015 John Wiley & Sons, Ltd.     

Modulation of excitatory neurotransmission by neuronal/glial signalling molecules: interplay between purinergic and glutamatergic systems

Glutamate is the main excitatory neurotransmitter of the central nervous system (CNS), released both from neurons and glial cells. Acting via ionotropic (NMDA, AMPA, kainate) and metabotropic glutamate receptors, it is critically involved in essential regulatory functions. Disturbances of glutamatergic neurotransmission can be detected in cognitive and neurodegenerative disorders. This paper summarizes the present knowledge on the modulation of glutamate-mediated responses in the CNS. Emphasis will be put on NMDA receptor channels, which are essential executive and integrative elements of the glutamatergic system. This receptor is crucial for proper functioning of neuronal circuits; its hypofunction or overactivation can result in neuronal disturbances and neurotoxicity. Somewhat surprisingly, NMDA receptors are not widely targeted by pharmacotherapy in clinics; their robust activation or inhibition seems to be desirable only in exceptional cases. However, their fine-tuning might provide a promising manipulation to optimize the activity of the glutamatergic system and to restore proper CNS function. This orchestration utilizes several neuromodulators. Besides the classical ones such as dopamine, novel candidates emerged in the last two decades. The purinergic system is a promising possibility to optimize the activity of the glutamatergic system. It exerts not only direct and indirect influences on NMDA receptors but, by modulating glutamatergic transmission, also plays an important role in glia-neuron communication. These purinergic functions will be illustrated mostly by depicting the modulatory role of the purinergic system on glutamatergic transmission in the prefrontal cortex, a CNS area important for attention, memory and learning.     

Proto-dolomite formation in microbial consortia dominated by Halomonas strains

Extremophiles - Microbes can be found in hypersaline environments forming diverse populations with complex ecological interactions. Microbes in such environments were found to be involved in the...     

Nanocomposite scaffold seeded with mesenchymal stem cells for bone repair

The mechanical property of bone tissue scaffolds is one of the most important aspects in bone tissue engineering that has remained problematic. In our previous study, we fabricated a three‐dimensional scaffold from nano‐hydroxyapatite/gelatin (nHA/Gel) and investigated its efficiency in promoting bone regeneration both in vitro and in vivo. In the present study, the effect of adding silicon carbide (SiC) on the mechanical and biological behaviors of the nHA/Gel/SiC and bone regeneration in vivo were determined. nHA and SiC were synthesized and characterized by the X‐ray diffraction pattern and transmission electron microscope image. Layer solvent casting, freeze drying, and lamination techniques were applied to prepare these scaffolds. Then, the biocompatibility and cell adhesion behavior of the synthesized nHA/Gel/SiC scaffolds were investigated. For in vivo studies, rats were categorized into three groups: blank defect, blank scaffold, and rat bone marrow mesenchymal stem cells (rBM‐MSCs)/scaffold. After 1, 4, and 12 weeks post‐injury, the rats were sacrificed and the calvaria were harvested. Sections with a thickness of 5 µm thickness were prepared and stained with hematoxylin–eosin and Masson's Trichrome, and immunohistochemistry was performed. Our results showed that SiC effectively increased the mechanical properties of the nHA/Gel/SiC scaffold. No significant differences were observed in biocompatibility, cell adhesion, and cytotoxicity of the nHA/Gel/SiC in comparison with the nHA/Gel nanocomposite. Based on histological and immunohistochemical studies, both osteogenesis and collagenization were significantly higher in the rBM‐MSCs/scaffold group, quantitatively and qualitatively. The present study strongly suggests the potential of SiC as an alternative strategy to improve the mechanical and biological properties of bone tissue engineering scaffolds, and shows that the pre‐seeded nHA/Gel/SiC scaffold with rBM‐MSCs improves osteogenesis in the engineered bone implant.