Proteomics of early and late cold shock stress on thermophilic bacterium, Thermus sp. GH5

Thermus sp. GH5 is an aerobic thermophilic bacterium with optimal growth at 70-75°C isolated from a hot spring in Ardabil, North West province of Iran. Due to industrial and biotechnological applications of thermophils, it is very important to know more about their proteomes and metabolomes. Since thermophils live in stressful environments it will be very useful to study their survival mechanisms. There are many reports on stress induced proteins, particularly the well characterized heat shock proteins, but little is known about the functions of proteins induced after a decrease in temperature. In this study, the proteomes of the thermophilic bacterium after a temperature down shift from 75°C to 45°C for 2h and 5h were investigated. We also compared protein profiles of early and late cold shock processes to that of cells grown at 75°C and identified a set of proteins, some of which are involved in metabolic processes such as fatty acid synthesis, pentose phosphate pathway, aromatic component degradation and signal transduction. Our data showed this organism could be tolerating the stress conditions by changing its metabolism and physiology.     

Astaxanthin Modulates Autophagy,Apoptosis, and Neuronal Oxidative Stress in a Rat Model of Compression Spinal Cord Injury

The effects of astaxanthin (AST) were evaluated on oxidative mediators, neuronal apoptosis, and autophagy in functional motor recovery after spinal cord injury (SCI). Rats were divided into three groups of sham, SCI?+?DMSO (dimethyl sulfoxide), and SCI?+?AST. Rats in the sham group only underwent a laminectomy at thoracic 8–9. While, the SCI?+?DMSO and SCI?+?AST groups had a compression SCI with an aneurysm clip. Then, this groups received an intrathecal (i.t.) injection of 5% DMSO and AST (10 μl of 0.005 mg/kg), respectively. The rat motor functions were assessed weekly until the 28th day using a combined behavioral score (CBS). Total antioxidant capacity (TAC), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were measured in spinal tissue to evaluate oxidative stress-related parameters. Besides, autophagy-related proteins (P62, LC3B, and Beclin1) and apoptosis-associated proteins (Bax and Bcl2) were determined using western blotting on the 1st and 7th days after surgery. Hematoxylin–eosin and Fluoro-Jade B staining were performed to detect the histological alterations and neuronal degeneration. As the result, treatment with AST potentially attenuated rat CBS scores (p?<?0.001) towards a better motor performance. AST significantly reduced the spinal level of oxidative stress by increasing TAC, SOD, and GPx, while decreasing MDA (p?<?0.001). Furthermore, AST treatment remarkably upregulated expression of LC3B (p?<?0.001), and Beclin1 (p?<?0.05) in the spinal cord, but downregulated P62 (p?<?0.05) and the Bax/Bcl2 ratio (p?<?0.001). Consequently, AST reduced SCI-induced histological alterations and neuronal degeneration (p?<?0.001). In conclusion, AST can improve motor function after SCI by reducing oxidative stress/apoptosis and increasing neuronal autophagy.

     

Oral Mycobiome Analysis of HIV-Infected Patients: Identification of Pichia as an Antagonist of Opportunistic Fungi

Oral microbiota contribute to health and disease, and their disruption may influence the course of oral diseases. Here, we used pyrosequencing to characterize the oral bacteriome and mycobiome of 12 HIV-infected patients and matched 12 uninfected controls. The number of bacterial and fungal genera in individuals ranged between 8–14 and 1–9, among uninfected and HIV-infected participants, respectively. The core oral bacteriome (COB) comprised 14 genera, of which 13 were common between the two groups. In contrast, the core oral mycobiome (COM) differed between HIV-infected and uninfected individuals, with Candida being the predominant fungus in both groups. Among Candida species, C. albicans was the most common (58% in uninfected and 83% in HIV-infected participants). Furthermore, 15 and 12 bacteria-fungi pairs were correlated significantly within uninfected and HIV-infected groups, respectively. Increase in Candida colonization was associated with a concomitant decrease in the abundance of Pichia, suggesting antagonism. We found that Pichia spent medium (PSM) inhibited growth of Candida, Aspergillus and Fusarium. Moreover, Pichia cells and PSM inhibited Candida biofilms (P = .002 and .02, respectively, compared to untreated controls). The mechanism by which Pichia inhibited Candida involved nutrient limitation, and modulation of growth and virulence factors. Finally, in an experimental murine model of oral candidiasis, we demonstrated that mice treated with PSM exhibited significantly lower infection score (P = .011) and fungal burden (P = .04) compared to untreated mice. Moreover, tongues of PSM-treated mice had few hyphae and intact epithelium, while vehicle- and nystatin-treated mice exhibited extensive fungal invasion of tissue with epithelial disruption. These results showed that PSM was efficacious against oral candidiasis in vitro and in vivo. The inhibitory activity of PSM was associated with secretory protein/s. Our findings provide the first evidence of interaction among members of the oral mycobiota, and identifies a potential novel antifungal.     

Bridging the gaps between research,policy and practice in low- and middle-income countries: a survey of researchers

Background

Many international statements have urged researchers, policy-makers and health care providers to collaborate in efforts to bridge the gaps between research, policy and practice in low- and middle-income countries. We surveyed researchers in 10 countries about their involvement in such efforts.

Methods

We surveyed 308 researchers who conducted research on one of four clinical areas relevant to the Millennium Development Goals (prevention of malaria, care of women seeking contraception, care of children with diarrhea and care of patients with tuberculosis) in each of 10 low- and middle-income countries (China, Ghana, India, Iran, Kazakhstan, Laos, Mexico, Pakistan, Senegal and Tanzania). We focused on their engagement in three promising bridging activities and examined system-level, organizational and individual correlates of these activities.

Results

Less than half of the researchers surveyed reported that they engaged in one or more of the three promising bridging activities: 27% provided systematic reviews of the research literature to their target audiences, 40% provided access to a searchable database of research products on their topic, and 43% established or maintained long-term partnerships related to their topic with representatives of the target audience. Three factors emerged as statistically significant predictors of respondents’ engagement in these activities: the existence of structures and processes to link researchers and their target audiences predicted both the provision of access to a database (odds ratio [OR] 2.62, 95% CI 1.30–5.27) and the establishment or maintenance of partnerships (OR 2.65, 95% CI 1.25–5.64); stability in their contacts predicted the provision of systematic reviews (OR 2.88, 95% CI 1.35–6.13); and having managers and public (government) policy-makers among their target audiences predicted the provision of both systematic reviews (OR 4.57, 95% CI 1.78–11.72) and access to a database (OR 2.55, 95% CI 1.20–5.43).

Interpretation

Our findings suggest potential areas for improvement in light of the bridging strategies targeted at health care providers that have been found to be effective in some contexts and the factors that appear to increase the prospects for using research in policy-making.The need to bridge the gaps between research, policy and practice appears to be a global phenomenon. Three recent, highly visible resolutions — the Mexico Action Statement on Health Research in 2004 (58 countries),¹ the related World Health Assembly resolution in 2005 (193 countries)² and the Bamako Call to Action on Research for Health in 2008 (53 countries) ³ — urged researchers, policy-makers and health care providers to collaborate in efforts to bridge these gaps. These efforts can range from bringing research-based evidence to the attention of those who could use it, to making research-based evidence available so that it can be readily retrieved when needed.We are not aware of a survey having been conducted in a range of low- and middle-income countries about researchers’ bridging activities related to specific high-priority health topics. Researchers and research organizations have been surveyed about their bridging activities in single high-income countries such as Canada.^4–6 Guideline-producing organizations and health technology assessment agencies have also been surveyed about their bridging activities;⁷ only in one case was the focus on bridging activities in low- and middle-income countries.⁸ Select research funding agencies have been studied in low- and middle-income countries.⁹ Yet the Millennium Development Goals and the goals of many countries call for topic-focused efforts to bridge the gaps between research, policy and practice.We studied efforts to bridge the gaps between research, policy and practice in 10 low- and middle-income countries (China, Ghana, India, Iran, Kazakhstan, Laos, Mexico, Pakistan, Senegal and Tanzania). In this article, we describe the findings from a survey of researchers in these countries who conducted research in one of four clinical areas relevant to the Millennium Development Goals: prevention of malaria (Ghana, Laos, Senegal and Tanzania), care of women seeking contraception (China, Kazakhstan, Laos and Mexico), care of children with diarrhea (Ghana, India, Pakistan and Senegal) and care of patients with tuberculosis (China, India, Iran and Mexico). In a related article, we describe the findings from a survey of health care providers in these countries who were practising in one of these clinical areas about their awareness of, access to and use of research-based evidence in these clinical areas and the influence of such evidence on their professional practice.¹⁰The challenges associated with documenting such efforts include cross-country differences in the capacity to conduct surveys of researchers; the visibility of researchers depending on their alignment with priorities of government, development agencies, research funding agencies and industry (and hence their likelihood of being identified to participate in these surveys); and researchers’ familiarity with and attitudes toward the bridging activities asked about in these surveys.     

Priming with oxytocin and relaxin improves cardiac differentiation of adipose tissue–derived stem cells

Previous studies have identified the heart as a source and a target tissue for oxytocin and relaxin hormones. These hormones play important roles in the regulation of cardiovascular function and repair of ischemic heart injury. In the current study, we examined the impact of oxytocin and relaxin on the development of cardiomyocytes from mesenchymal stem cells. For this purpose, mouse adipose tissue–derived stem cells (ADSCs) were treated with different concentrations of oxytocin or relaxin for 4 days. Three weeks after initiation of cardiac induction, differentiated ADSCs expressed cardiac-specific genes, Gata4, Mef2c, Nkx2.5, Tbx5, α- and β-Mhc, Mlc2v, Mlc2a and Anp, and cardiac proteins including connexin 43, desmin and α-actinin. 10 ⁻⁷ M oxytocin and 50 ng/mL relaxin induced the maximum upregulation in the expression of cardiac markers. A combination of oxytocin and relaxin induced cardiomyocyte differentiation more potently than the individual factors. In our experiment, oxytocin-relaxin combination increased the population of cardiac troponin I-expressing cells to 6.84% as compared with 2.36% for the untreated ADSCs, 3.7% for oxytocin treatment and 3.41% for relaxin treatment groups. In summary, the results of this study indicated that oxytocin and relaxin hormones individually and in combination can improve cardiac differentiation of ADSCs, and treatment of the ADSCs and possibly other mesenchymal stem cells with these hormones may enhance their cardiogenic differentiation and survival after transplantation into the ischemic heart tissue.     

Arachidonic acid alleviates the detrimental effects of acetylsalicylic acid on human granulosa cells performance in vitro

Here, we investigated the biological effects of arachidonic acid (AA) in human cumulus granulosa cells (CGCs) after exposure to ASA. Cells were isolated from the follicular fluid and incubated with 0.5 mM acetylsalicylic acid (ASA) and 50 µM AA. Cell viability was analyzed by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. E₂ and P₄ levels were measured by chemiluminescence assay. Expression of genes including CYP19A1, FACN, and SCD1 was measured by real‐time polymerase chain reaction assay. Oxidative status was analyzed by monitoring glutathione peroxidase activity. The fatty acid profile was analyzed by the gas chromatography technique. Enzyme‐linked immunosorbent assay was used to measure prostaglandin E₂ (PGE₂) in CGCs after exposure to ASA and AA. Protein levels of the estrogen receptor were studied by immunofluorescence staining. Ultrastructural changes were evaluated by transmission electron microscopy imaging. ASA treatment reduced E₂ production, Cyp19a1 expression, glutathione peroxidase (GPx) activity, and estradiol receptor expression in CGCs. The addition of AA prevented the ASA‐induced E₂ reduction (p < .05) and expression of Cyp19a1. Moreover, AA increased the antioxidant capacity of CGCs exposed to ASA by promoting GPx activity (p < .05). AA increased monounsaturated fatty acid/saturated fatty acid ratio compared with the ASA group (p < .05). AA supplementation triggered the synthesis and secretion of PGE₂ in ASA‐treated CGCS (p < .05). Cytoplasmic vacuolation observed in the ASA group and treatment with AA intensified vacuolation rate. The expression of the estrogen receptor was increased after AA supplementation. Data demonstrated that AA decreased the detrimental effects of ASA on human CGCs after 72 hr.     

Novel method for detection probability and estimating population size of mountain frog,Rana macrocnemis (Boulenger, 1885) at the end of its distribution range

Landscape and Ecological Engineering - Local amphibian populations at the edge of a species range are possibly of greater conservation concern than any other amphibians group. They experience...     

Electric field effect on the zigzag (6,0) single-wall BC2N nanotube for use in nano-electronic circuits

We have analyzed the effect of external electric field on the zigzag (6,0) single-wall BC₂N nanotube using density functional theory calculations. Analysis of the structural parameters indicates that the nanotube is resistant against the external electric field strengths. Analysis of the electronic structure of the nanotube indicates that the applied parallel electric field strengths have a much stronger interaction with the nanotube with respect to the transverse electric field strengths and the nanotube is easier to modulate by the applied parallel electric field. Our results show that the properties of the nanotube can be controlled by the proper external electric field for use in nano-electronic circuits.

Antibody humanization methods – a review and update

This article reviews recent advances achieved during recent years on various aspects of antibody humanization theories and techniques. Common methods for producing humanized antibodies including framework-homology-based humanization, germline humanization, complementary determining regions (CDR)-homology-based humanization and specificity determining residues (SDR) grafting, as well as advantages and disadvantages of each of these methods and their applications are discussed.