Label-free, real-time detection of the dynamic processes of protein degradation using oblique-incidence reflectivity difference method

Based on the requirements for studying the dynamic process of proteinase action substrates in life science, we selected six random proteins including 1L-10, SCGB2A2, CENPQ, GST, HK1, KLHL7, as well as five different concentrations of 1L-10 proteins of 1 mg/ml, 0.5 mg/ml, 0.25 mg/ml, 0.125 mg/ml, and 0.0625 mg/ml, and fabricated two types of substrate protein microarrays, respectively. We detected the dynamic processes of proteins degraded by proteinase K using oblique-incidence reflectivity difference (OIRD) method in a label-free and real-time manner. We obtained the relevant degradation velocities and the degradation time. The experimental results demonstrate that OIRD has the ability to study proteinase action substrates which is out of reach of label methods and is expected to offer opportunities to determine protease-substrate relationships on the systems biology level.

Combined seawater toilet flushing and urine separation for economic phosphorus recovery and nitrogen removal: a laboratory-scale trial

Freshwater toilet flushing consumes 20-35% of typical household water demand. Seawater toilet flushing, as practised by Hong Kong since 1958, provides an alternative water source. To maximise the benefits of this unique dual water supply, urine separation could be combined to allow low-cost struvite production and subsequent urine nitrification - in-sewer denitrification. This paper reports on a laboratory-scale study of seawater urine phosphate recovery (SUPR) and seawater-urine nitrification. A laboratory-scale SUPR reactor was run under three phases with hydraulic retention time between 1.5 and 6 h, achieving 91-96% phosphorus recovery. A urine nitrification sequencing batch reactor (UNSBR) was also run for a period of over 650 days, averaging 90% ammonia removal and loading of up to 750 mg-N/L.d. Careful control of the SUPR phosphate removal was found necessary for operation of the downstream UNSBR, and system integration considerations are discussed.

39 EFFECT OF FOLLICULAR SIZE OF CYTOPLAST DONOR ON CLONING EFFICIENCY IN GOATS

In goats, oocytes derived from small follicles (<3 mm in diameter) have low developmental competence after IVF (Crozet et al. 1995). However, their performance is compatible to oocytes derived from large follicles (>3 mm) when intracytoplasmic sperm injection is used (Jimenez-Macedo et al. 2006). No data are currently available on the ability of oocytes derived from small follicles to support development to term after somatic cell nuclear transfer (SCNT) in goats. Here we evaluated the effect of follicular size of cytoplast donor on cloning efficiency in goats. Seven rounds of oocyte maturation and nuclear transfer were carried out on separate days. During each replicate, oocytes were collected separately from large follicles (LF, n = 378) and small follicles (SF, n = 981) from the same group of ovaries. First, only large follicles (>3 mm) were dissected and rinsed, and then an ovary was moved to another dish to dissect the rest of the follicles. The groups of oocytes derived from LF and SF were treated separately throughout the process including maturation, SCNT, embryo culture and embryo transfers. Neonatal skin fibroblasts derived from transgenic goats were used as nuclear donors in this study. Nine embryo transfers were conducted for LF group and 12 for the SF group. Oocytes from SF had significantly lower rate of nuclear maturation compared to oocytes derived from LF (33.5% ± 3.7 v. 54.3% ± 5.4; P < 0.01). There was no difference in fusion rate between these 2 groups (66 v. 69%; 215/325 v. 138/199; SF v. LF). Additionally, we found no statistical difference in Day 30 pregnancy rate (42% v. 33%; SF v. LF group) or birth rate (2 healthy kids produced from each of the groups, 16.7% v. 22.2%; SF v. LF). The results demonstrate that oocytes from small follicles have similar competence to support development to term as oocytes derived from large follicles following SCNT in goats. This work was supported by the Utah Multidisciplinary Arrhythmia Consortium and Utah Agricultural Experiment Station project #1100.

The external Q factor of a dual-feed coupling for superconducting radio frequency cavities: theoretical and experimental studies

We propose a theoretical model based on network analysis to study the external quality factor (Q factor) of dual-feed coupling for superconducting radio-frequency (SRF) cavities. Specifically, we apply our model to the dual-feed 704 MHz half-cell SRF gun for Brookhaven National Laboratory's prototype Energy Recovery Linac (ERL). The calculations show that the external Q factor of this dual-feed system is adjustable from 10(4) to 10(9) provided that the adjustment range of a phase shifter covers 0°-360°. With a period of 360°, the external Q factor of the coupling system changes periodically with the phase difference between the two coupling arms. When the RF phase of both coupling arms is adjusted simultaneously in the same direction, the external Q factor of the system also changes periodically, but with a period of 180°.

Simultaneous optimization of spin fluctuations and superconductivity under pressure in an iron-based superconductor

We present a high-pressure NMR study of the overdoped iron pnictide superconductor NaFe0.94Co0.06As. The low-energy antiferromagnetic spin fluctuations in the normal state, manifest as the Curie-Weiss upturn in the spin-lattice relaxation rate 1/(75)T1T, first increase strongly with pressure but fall again at P>Popt=2.2  GPa. Neither long-ranged magnetic order nor a structural phase transition is encountered up to 2.5 GPa. The superconducting transition temperature Tc shows a pressure dependence identical to the spin fluctuations. Our observations demonstrate that magnetic correlations and superconductivity are optimized simultaneously as a function of the electronic structure, thereby supporting very strongly a magnetic origin of superconductivity.

Parathyroid hormone-related protein inhibits DKK1 expression through c-Jun-mediated inhibition of β-catenin activation of the DKK1 promoter in prostate cancer

Prostate cancer (PCa)bone metastases are unique in that majority of them induce excessive mineralized bone matrix, through undefined mechanisms, as opposed to most other cancers that induce bone resorption. Parathyroid hormone-related protein (PTHrP) is produced by PCa cells and intermittent PTHrP exposure has bone anabolic effects, suggesting that PTHrP could contribute to the excess bone mineralization. Wnts are bone-productive factors produced by PCa cells, and the Wnt inhibitor Dickkopfs-1 (DKK1) has been shown to promote PCa progression. These findings, in conjunction with the observation that PTHrP expression increases and DKK1 expression decreases as PCa progresses, led to the hypothesis that PTHrP could be a negative regulator of DKK1 expression in PCa cells and, hence, allow the osteoblastic activity of Wnts to be realized. To test this, we first demonstrated that PTHrP downregulated DKK1 mRNA and protein expression. We then found through multiple mutated DKK1 promoter assays that PTHrP, through c-Jun activation, downregulated the DKK1 promoter through a transcription factor (TCF) response element site. Furthermore, chromatin immunoprecipitation (ChIP) and re-ChIP assays revealed that PTHrP mediated this effect through inducing c-Jun to bind to a transcriptional activator complex consisting of β-catenin, which binds the most proximal DKK1 promoter, the TCF response element. Together, these results demonstrate a novel signaling linkage between PTHrP and Wnt signaling pathways that results in downregulation of a Wnt inhibitor allowing for Wnt activity that could contribute the osteoblastic nature of PCa.

Characterization of large deletions in the F8 gene using multiple competitive amplification and the genome walking technique

BACKGROUND

Large deletions in the F8 gene are responsible for approximately 3% of severe hemophilia A (HA) cases. However, only a few breakpoints in large deletions have been characterized.

OBJECTIVES

To identify large deletions in the F8 gene and to characterize the molecular mechanisms leading to these deletions.

PATIENTS AND METHODS

We used AccuCopy technology, a copy number variation (CNV) genotyping method based on multiplex competitive amplification, to confirm deletions in index patients and to screen potential female carriers in 10 HA families. Also, breakpoints of these large deletions were characterized by a primer walking strategy and genome walking technique.

RESULTS

Ten large deletions and four female carriers were identified by AccuCopy. The extents of deleted regions ranged from 1.3 to 68.5 kb. Exact breakpoints of these deletions were successfully characterized. Eight of them presented microhomologies at breakpoint junctions and several recombination-associated elements (repetitive elements, non-B conformation forming motifs and sequence motifs) were also observed in close proximity to the junctions.

CONCLUSIONS

AccuCopy technology is a reliable and efficient tool for detecting large deletions in the F8 gene and identifying HA female carriers. The genome walking technique is a highly specific, efficient and versatile method for characterizing the deletion breakpoints. Molecular characterization of deletion breakpoints revealed that non-homologous end joining and microhomology-mediated replication-dependent recombination were the major causative mechanisms of the 10 large deletions in the F8 gene.

Development of multiplex real-time PCR for simultaneous detection of three Potyviruses in tobacco plants

AIMS

To develop a multiplex real-time PCR assay using TaqMan probes for the simultaneous detection and quantification of Tobacco etch virus (TEV), Potato virus Y (PVY) and Tobacco vein banding mosaic virus (TVBMV).

METHODS AND RESULTS

Specific primer and probe combinations for TEV and TVBMV were developed from the coat protein region of the viral genome. To detect PVY, a primer and probe combination PVY-Univ F, PVY-Univ R and PVY-Univ P for amplifying the coat protein region of the virus genome was employed. The detection limit of multiplex real-time PCR for these viruses was 10 copies μl(-1) of the standard plasmid. The multiplex reaction was successful in the detection of these three pathogens, with no non-specific amplification and cross-reaction.

CONCLUSIONS

This multiplex real-time PCR provides a rapid, effective, specific and sensitive method for the simultaneous detection and quantification of the three pathogens on infected tobacco plants.

SIGNIFICANCE AND IMPACT OF THE STUDY

This multiplex real-time PCR will be useful not only for diagnostic, ecological, epidemiological and pathogenesis studies, but also for investigating host/virus or virus/virus interactions, in particular during mix infection.

Human skin neural crest progenitor cells are susceptible to BRAF(V600E)-induced transformation

Adult stem cells are multipotent and persist in small numbers in adult tissues throughout the lifespan of an organism. Unlike differentiated cells, adult stem cells are intrinsically resistant to senescence. It is unclear how adult stem cells in solid organs respond to oncogenic stimulation and whether these cells have a role in tumor initiation. We report here that expression of BRAF(V600E) in human neural crest progenitor cells (hNCPCs) did not induce growth arrest as seen in human melanocytes, but instead, increased their cell proliferation capacity. These cells (hNCPCs(V600E)) acquired anchorage-independent growth ability and were weakly tumorigenic in vivo. Unlike in human melanocytes, BRAF(V600E) expression in hNCPCs did not induce p16(INK4a) expression. BRAF(V600E) induced elevated expression of CDK2, CDK4, MITF and EST1/2 protein in hNCPCs, and also induced melanocytic differentiation of these cells. Furthermore, overexpression of MITF in hNCPCs(V600E) dramatically increased their tumorigenicity and resulted in fully transformed tumor cells. These findings indicate that hNCPCs are susceptible to BRAF(V600E)-induced transformation, and MITF potentiates the oncogenic effect of BRAF(V600E) in these progenitor cells. These results suggest that the hNCPCs are potential targets for BRAF(V600E)-induced melanocytic tumor formation.

Application of magnifying endoscopy with narrow-band imaging in diagnosing gastric lesions: a prospective study

BACKGROUND

Magnifying endoscopy with narrow-band imaging (ME-NBI) can more clearly assess the surface pattern and microvascular architecture of gastric lesions.

OBJECTIVE

To evaluate the diagnostic efficacy of ME-NBI in patients with early gastric cancer.

DESIGN

Prospective study.

SETTING

Single academic center.

PATIENTS

This study involved 164 suspected gastric lesions in 146 consecutive patients who underwent ME-NBI for additional differential diagnosis before treatment.

INTERVENTION

ME-NBI findings were classified into 3 groups based on irregularities, absence of surface pattern, and microvascular architecture. All lesions were treated endoscopically or surgically, and ME-NBI diagnosis was compared with histopathological findings.

MAIN OUTCOME MEASUREMENTS

Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of real-time ME-NBI diagnosis were determined.

RESULTS

The sensitivity, specificity, and accuracy of ME-NBI were 97.3%, 84.4%, and 90.2%, respectively, in distinguishing between cancerous and noncancerous lesions and were 92.3%, 89.7%, and 90.4%, respectively, in distinguishing undifferentiated from differentiated adenocarcinoma. ME-NBI accurately predicted depth of invasion in 37 of 39 differentiated adenocarcinomas (95%).

LIMITATIONS

The sample size was relatively small.

CONCLUSIONS

ME-NBI can successfully distinguish between cancerous and noncancerous lesions and between undifferentiated and differentiated adenocarcinomas. Of the 3 patterns on ME-NBI, type A is mainly characteristic of noncancerous lesions, type B is a good indicator of differentiated adenocarcinoma and intramucosal/superficially invasive cancers, and type C is indicative of undifferentiated adenocarcinoma or differentiated cancer with deep submucosal invasion.

Suicidal thoughts and behaviors in older adults in rural China: a preliminary study

BACKGROUND

One purpose of this study was to examine the feasibility of conducting epidemiological survey on suicidal thoughts and behaviors (hereafter "suicidal thoughts/behaviors"; i.e., any suicidal ideation, serious ideation, planning, and attempts) among older adults in rural China. Another purpose was to investigate among older people in rural China the prevalence of suicidal thoughts/behaviors, as well as their sociodemographic and clinical correlates.

METHODS

A randomly selected sample of 263 subjects, 50 years or older, was recruited in a remote rural area of Southwestern China (Mianyang Region, Sichuan Province) and interviewed using structured instruments. Basic sociodemographic and clinical data were collected.

RESULTS

There was no refusal among approached subjects, and subjects were willing to answer questions on suicidal thoughts/behaviors. The lifetime prevalence of suicidal ideation, serious ideation, planning, and attempt was 28.9% (23.4%-34.4%), 19.7% (14.9%-24.6%), 11.4% (7.5%-15.3%), and 5.3% (2.6%-8.1%), respectively. The corresponding 12-month prevalence was 8.8% (5.3%-12.2%), 5.3% (2.6%-8.1%), 2.7% (0.7%-4.6%), and 0%, respectively. The 2-week prevalence was 3.4% (1.2%-5.6%), 2.3% (0.5%-4.1%), 2.3% (0.5%-4.1%), and 0%, respectively. Correlates of suicidal thoughts/behaviors of this group are similar to findings from other community studies, such as female gender, unmarried status, major medical conditions, insomnia, financial difficulties and lower education, depressive symptoms, recent stressful life events, greater life dissatisfaction.

CONCLUSIONS

Our findings suggest that larger scale epidemiological survey of suicidal thoughts/behaviors on older adults in rural China would be feasible. Suicidal thoughts/behaviors are common among older people in rural China, as seen in this preliminary study, which points to the need for further larger scale investigations.

Combination treatment of stroke with sub-therapeutic doses of Simvastatin and human umbilical cord blood cells enhances vascular remodeling and improves functional outcome

Human umbilical cord blood cells (HUCBCs) have been employed as a restorative treatment for experimental stroke. In this study, we investigated whether transplantation of sub-therapeutic doses of HUCBCs and Simvastatin enhances cerebral vascular remodeling after stroke. Adult male Wistar rats (n=34) were subjected to transient middle cerebral artery occlusion (MCAo) and treated with: phosphate-buffered solution (PBS, gavaged daily for 7 days); Simvastatin (0.5mg/kg, gavaged daily for 7 days); HUCBCs (1×10(6), injected once via tail vein); and combination Simvasatin with HUCBCs, starting at 24h after MCAo. There was no significant difference between Simvastatin- or HUCBC-monotherapy and MCAo-alone group. Combination treatment 24h post-stroke significantly increased the perimeter of von Willebrand factor (vWF)-positive vessels, the diameter and density of alpha smooth muscle actin (αSMA)-positive arteries, and the percentage of 5-bromodeoxyuridine (BrdU)-positive endothelial cells (ECs) in the ischemic boundary zone (IBZ) compared with MCAo-alone or HUCBC-monotherapy 14 days after MCAo (p<0.05, n=8/group); Combination treatment significantly increased the densities of vWF-vessels and αSMA-arteries as well as the densities of BrdU-ECs and BrdU-positive smooth muscle cells (SMCs) in vascular walls in the IBZ compared with Simvastatin-monotherapy. Moreover, the increased BrdU-ECs and BrdU-SMCs were significantly correlated with neurological functional outcome 14 days after MCAo. Combination treatment also significantly increased the expression of Angiopoietin-1 (Ang1), Tie2 and Occludin in the IBZ (p<0.05, n=8/group). The in vitro experiments showed that combination treatment and Ang1 significantly increased capillary-like tube formation and arterial cell migration; anti-Ang1 significantly reduced combination treatment-induced tube-formation and artery cell migration (p<0.05, n=6/group). These findings indicated that a combination of sub-therapeutic doses of Simvastatin and HUCBCs treatment of stroke increases Ang1/Tie2 and Occludin expression in the ischemic brain, amplifies endogenous angiogenesis and arteriogenesis, and enhances vascular remodeling which in concert may contribute to functional outcome after stroke.

Fabrication and characterization of n-ZnO nanonails array/p(+)-GaN heterojunction diode

A novel heterojunctional structure of n-ZnO nanonails array/p(+)-GaN light-emitting diode was fabricated by Chemical Vapor Deposition method. A broad electroluminescence spectrum shows two peaks centered at 435 nm and 478 nm at room temperature, respectively. By comparing the photoluminescence and electroluminescence spectra, together with analyzing the energy band structure of heterojunction light emitting diode, it suggested that the electroluminescence peak located at 435 nm originates from Mg acceptor level of p(+)-GaN layer, whereas the electroluminescence peak located at 478 nm originates from the defects of n-ZnO nanonails array.