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Saccharomyces cerevisiae-based expression systems, which rely on safe, food-grade strains, are low cost, simple to operate, and can be used for large-scale fermentation. However, low levels of foreign protein expression by S. cerevisiae have limited their widespread application. The ability of the endoplasmic reticulum (ER) to fold and process foreign proteins is an important factor restricting the expression of foreign proteins. In the current study, the effects of transcription factor Hac1p, which is involved in the unfolded protein response pathway, on S. cerevisiae-based expression of xylanase gene xynB from Aspergillus niger were examined. Overlap extension polymerase chain reaction (PCR), rDNA integration and droplet digital PCR technology were used to generate a S. cerevisiae strain (S8) containing eight copies of xynB, allowing high-yield secretory expression of xylanase. The effects of subsequent overexpression of HAC1 in strain S8 on the expression of genes associated with protein folding in the ER were then examined using the GeXP system. Results confirmed the constitutive secretory expression of the multiple copies of xynB following rDNA-based integration of the expression cassette, with a maximum xylanase yield of 325 U/mL. However, overexpression of HAC1 further improved xylanase production by strain S8, resulting in a yield of 381 U/mL. [ABSTRACT FROM AUTHOR]

Leishmaniasis is an important parasitic disease, and definite diagnosis using a specific and sensitive method is the first step to cure the disease. Here, we present a novel diagnostic strategy based on serum peptide profiling by magnetic beads and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The serum peptides from the Leishmani donovani-infected and healthy mice were enriched by the optimized magnetic beads. The mass spectrograms were acquired by MALDI-TOF MS and analyzed by the ClinProTools bioinformatics software from Bruker Daltonics. The diagnostic model of serum peptide profiling produced by the ClinProTools software could correctly detect L. donovani infection in mice from the third day post-infection, with the accuracy of 94.1%, sensitivity of 92.4%, and specificity of 97.1%, respectively. The results of the present study suggested that the serum peptide profiling by MALDI-TOF MS is a novel potential tool for the clinical diagnosis of leishmaniasis. [ABSTRACT FROM AUTHOR]

Localization is a vital task in underwater wireless sensor networks (UWSNs). Accurate location information is critical for applications such as environmental monitoring and military operations. Received signal strength (RSS)-based localization schemes are commonly employed because of their cost-effectiveness and performance in terrestrial environments. However, underwater acoustic environments are affected by not only path loss, but also absorption bias in which case these schemes perform poorly with large delays. This makes real-time underwater acoustic localization based on RSS challenging and unable to meet the localization requirements of practical applications. Thus, a real-time RSS-based target localization (RRTL) scheme for UWSNs is proposed. Since the derived closed-form expression is complex and nonconvex, an intelligent localization technique based on a backpropagation (BP) neural network is considered which employs improved differential evolution (IDE) to obtain the network weights and biases. First, improved opposition-based learning is used to obtain a robust population. Then an adaptive mutation strategy is utilized to improve global searching and convergence. Finally, optimized network parameters are obtained via IDE to train the BP neural network. Performance results are presented which demonstrate that the proposed method is superior to conventional state-of-the-art methods and is robust to absorption bias. For example, for an error cumulative distribution function (CDF) of 0.8 with N = 6, the proposed method provides an improvement of 69.7% in accuracy and 78.4% in computation time over the well-known WLS technique. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate symptom clusters and associated clinical factors in ambulatory multiple myeloma patients undergoing medication therapy. We also aimed to determine the correlations between symptom clusters and patient quality of life.Methods: A total of 174 multiple myeloma patients hospitalized in the haematology day unit were included in this study. A cross-sectional survey was conducted to examine symptoms and quality of life. Symptoms were assessed by the Chinese version of the Condensed Memorial Symptom Assessment Scale. Quality of life was measured with the Functional Assessment of Cancer Therapy-General. Principal component analysis was used to identify symptom clusters. Independent-samples t tests and chi-square tests were used for comparisons between groups. Spearman's rank correlation analysis was used to identify correlations.Results: We identified three symptom clusters in multiple myeloma patients: psychological; pain, dry mouth, and difficulty sleeping; and fatigue symptom cluster. For each symptom cluster, the patients could be categorized into a severe-symptom group or a mild-symptom group based on the distress of symptoms. The patients in each group exhibited differential demographic and clinical features. Symptom cluster distress was adversely correlated with patients' quality of life.Conclusions: Ambulatory multiple myeloma patients undergoing anticancer medication therapy experience multiple symptoms, which can be categorized into three symptom clusters. For each symptom cluster, level of distress was associated with patients' demographic and clinical characteristics. The presence and level of distress of these symptom clusters have adverse impacts on patients' quality of life. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance was used to develop a rapid, label-free and sensitive immunoassay for detection of Prion protein (PrP). Anti-PrP monoclonal antibodies immobilized on the biosensor surface were allowed to bind various concentrations of cellular prion protein (PrPC), followed by a pulse with additional soluble anti-PrP polyclonal antibodies to intensify the signal. The interaction of antibody with antigen was monitored in real time. With this method, it was possible to detect PrPC with a limit of 31.7 ng/ml in serum and 13.1 ng/ml in HEPES-saline, requiring 1 h for a single sample measurement. The assay also detected misfolded prion protein (PrPSc) in spiked serum and PrPSc in scrapie-infected mouse brains. This is a rapid and sensitive assay for the detection of PrP in serum that could be developed into a platform for a serum-based TSE test. [ABSTRACT FROM AUTHOR]

We describe a highly sensitive glucose probe based on carbon dots modified with MnO. A strong reduction of the green fluorescence of the carbon dots (CDs) happened due to the surface energy transfer (SET) from CDs to the deposited MnO. In the presence of HO (formed via enzymatic oxidation of glucose), fluorescence is restored because the MnO nanosheets are reduced to form colorless Mn(II) ions. These findings were used to design a fluorometric glucose assay that has a detection limit as low as 44 nM (at an S/N ratio of 3). [ABSTRACT FROM AUTHOR]

This study aimed to test the association between the European GWAS-identified risk IQGAP2 SNP rs457717 (A>G) and age-related hearing impairment (ARHI) in a Han male Chinese (HMC) population. A total of 2420 HMC subjects were divided into two groups [group 70+: >70 years ( n = 1306), and group 70−: ≤70 years ( n = 1114)]. The participants were categorised into case and control groups according to Z high scores for group 70− and the severity of hearing loss and different audiogram shapes identified by K-means cluster analysis for group 70+. The IQGAP2 tagSNP rs457717 was genotyped in accordance with the different ARHI phenotypes. The genotype distributions of IQGAP2 (AA/AG/GG) were not significantly different between the case and control groups ( P = 0.613 for group 70−; P = 0.602 for group 70+). Compared with genotype AA, the ORs of genotypes AG and GG for ARHI were not significantly different following adjustment for other environmental risk factors. We demonstrated that the IQGAP2 TagSNP rs457717 (A/G) was not associated with ARHI in HMC individuals. [ABSTRACT FROM AUTHOR]

Mitogen-activated protein kinases (MAPKs) regulate key signaling events in a variety of eukaryotic cells. Toxoplasma gondii, the causative agents of toxoplasmosis, possesses a p38α MAPK homologue, MAPK1, which is an important manipulator of host immunity and virulence in mice. In this work, we showed an increased transcript level of MAPK1 in T. gondii during bradyzoite differentiation induced by alkaline treatment and heat shock in vitro, suggesting that MAPK1 may be associated with bradyzoite differentiation. The biological roles of MAPK1 of T. gondii were investigated by construction of a MAPK1 deletion mutant (Δ mapk1) and a complementation mutant with restored MAPK1 expression using a type I strain. Knockout of MAPK1 resulted in markedly defective bradyzoite differentiation, host-cell attachment and parasite replication in vitro, and the inability to cause lethal infection in a murine model of acute toxoplasmosis, with lower parasite burden in infected tissues, showing that MAPK1 is associated with the acute virulence of parasite in mice. Complementation of MAPK1-deficient parasites restored bradyzoite development, attachment, replication, and virulence. Our findings demonstrate that MAPK1 is involved in asexual development and growth of T. gondii. [ABSTRACT FROM AUTHOR]

To evaluate the expression and location of epithelial sodium channels (ENaCs) in human nasal polyp and normal nasal mucosa, and to characterize the relevance of ENaCs to the development of NPs. Nasal polyp tissue from 17 patients and nasal mucosa from ten patients were obtained through endoscopic sinus surgery. The mRNA concentrations of ENaC-α, β, and γ were detected by real-time polymerase chain reaction. The expression of ENaC-α was detected using western blot and immunofluorescence techniques. The distribution of ENaC-α in mucosal tissue was observed using a laser scanning confocal microscope. The transcriptional expression of three subunits of ENaC was in the following order: α > β > γ, in both groups. The transcriptional expression of α, β, and γ subunits of ENaC was elevated in nasal polyp compared to nasal mucosa ( p < 0.01). ENaC-α expression was higher in nasal polyp than in nasal mucosa ( p < 0.05). Immunofluorescent staining indicated that ENaC-α protein was distributed in the epithelial cell apical membrane. The expression of ENaC is upregulated in human nasal polyp, which might in turn facilitate the formation and development of nasal polyp. [ABSTRACT FROM AUTHOR]