A comparative study of synthetic winged peptides for absolute protein quantification

A proper internal standard choice is critical for accurate, precise, and reproducible mass spectrometry-based proteomics assays. Synthetic isotopically labeled (SIL) proteins are currently considered the gold standard. However, they are costly and challenging to obtain. An alternative approach uses SIL peptides or SIL "winged" peptides extended at C- or/and N-terminus with an amino acid sequence or a tag cleaved during enzymatic proteolysis. However, a consensus on the design of a winged peptide for absolute quantification is missing. In this study, we used human serum albumin as a model system to compare the quantitative performance of reference SIL protein with four different designs of SIL winged peptides: (i) commercially available SIL peptides with a proprietary trypsin cleavable tag at C-terminus, (ii) SIL peptides extended with five amino acid residues at C-terminus, (iii) SIL peptides extended with three and (iv) with five amino acid residues at both C- and N-termini. Our results demonstrate properties of various SIL extended peptides designs, e.g., water solubility and efficiency of trypsin enzymatic cleavage with primary influence on quantitative performance. SIL winged peptides extended with three amino acids at both C- and N-termini demonstrated optimal quantitative performance, equivalent to the SIL protein

A case study for teaching information literacy skills

<p>Abstract</p> <p>Background</p> <p>The Internet has changed contemporary workplace skills, resulting in a need for proficiency with specific digital, online and web-based technologies within the fields of medicine, dentistry and public health. Although younger students, generally under 30 years of age, may appear inherently comfortable with the use of technology-intensive environments and digital or online search methods, competence in information literacy among these students may be lacking.</p> <p>Methods</p> <p>This project involved the design and assessment of a research-based assignment to help first-year, graduate-level health science students to develop and integrate information literacy skills with clinical relevance.</p> <p>Results</p> <p>One cohort of dental students (n = 78) was evaluated for this project and the results demonstrate that although all students were able to provide the correct response from the content-specific, or technology-independent, portion of the assignment, more than half (54%) were unable to demonstrate competence with a web-based, technology-dependent section of this assignment. No correlation was found between any demographic variable measured (gender, age, or race).</p> <p>Conclusion</p> <p>More evidence is emerging that demonstrates the need for developing curricula that integrates new knowledge and current evidence-based practices and technologies, traditionally isolated from graduate and health-care curricula, that can enhance biomedical and clinical training for students. This study provides evidence, critical for the evaluation of new practices, which can promote and facilitate the integration of information literacy into the curriculum.</p

Ascorbic Acid, Alcohol, and Environmental Chemicals a

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73093/1/j.1749-6632.1987.tb23775.x.pd

Asymmetric Wolbachia Segregation during Early Brugia malayi Embryogenesis Determines Its Distribution in Adult Host Tissues

Wolbachia are required for filarial nematode survival and fertility and contribute to the immune responses associated with human filarial diseases. Here we developed whole-mount immunofluorescence techniques to characterize Wolbachia somatic and germline transmission patterns and tissue distribution in Brugia malayi, a nematode responsible for lymphatic filariasis. In the initial embryonic divisions, Wolbachia segregate asymmetrically such that they occupy only a small subset of cells in the developing embryo, facilitating their concentration in the adult hypodermal chords and female germline. Wolbachia are not found in male reproductive tissues and the absence of Wolbachia from embryonic germline precursors in half of the embryos indicates Wolbachia loss from the male germline may occur in early embryogenesis. Wolbachia rely on fusion of hypodermal cells to populate adult chords. Finally, we detect Wolbachia in the secretory canal lumen suggesting living worms may release bacteria and/or their products into their host

Annexin II represents metastatic potential in clear-cell renal cell carcinoma

BACKGROUND: Annexin II (ANX2) is a multi-functional protein involved in cell proliferation and membrane physiology and is related to cancer progression. The purpose of this study was to assess ANX2 expression in clear-cell (cc) renal cell carcinoma (RCC)

BK Channels Regulate Spontaneous Action Potential Rhythmicity in the Suprachiasmatic Nucleus

Background: Circadian (,24 hr) rhythms are generated by the central pacemaker localized to the suprachiasmatic nucleus (SCN) of the hypothalamus. Although the basis for intrinsic rhythmicity is generally understood to rely on transcription factors encoded by ‘‘clock genes’’, less is known about the daily regulation of SCN neuronal activity patterns that communicate a circadian time signal to downstream behaviors and physiological systems. Action potentials in the SCN are necessary for the circadian timing of behavior, and individual SCN neurons modulate their spontaneous firing rate (SFR) over the daily cycle, suggesting that the circadian patterning of neuronal activity is necessary for normal behavioral rhythm expression. The BK K + channel plays an important role in suppressing spontaneous firing at night in SCN neurons. Deletion of the Kcnma1 gene, encoding the BK channel, causes degradation of circadian behavioral and physiological rhythms. Methodology/Principal Findings: To test the hypothesis that loss of robust behavioral rhythmicity in Kcnma1 2/2 mice is due to the disruption of SFR rhythms in the SCN, we used multi-electrode arrays to record extracellular action potentials from acute wild-type (WT) and Kcnma1 2/2 slices. Patterns of activity in the SCN were tracked simultaneously for up to 3 days, and the phase, period, and synchronization of SFR rhythms were examined. Loss of BK channels increased arrhythmicity but also altered the amplitude and period of rhythmic activity. Unexpectedly, Kcnma1 2/2 SCNs showed increased variability in the timing of the daily SFR peak

A review of the fossil record of turtles of the clade Pan-Carettochelys

Turtles of the total clade Pan-Carettochelys have a relatively poor fossil record that extends from the Early Cretaceous. The clade is only found in Asia during the Cretaceous, but spreads to Europe and North America during the Eocene. Neogene finds are restricted to Europe, Africa and Australia, whereas the only surviving species, Carettochelys insculpta, lives in New Guinea and the Northern Territories of Australia. The ecology of fossil pan-carettochelyids appears similar to that of the extant C. insculpta, although more primitive representatives were likely less adapted to brackish water. Current phylogenies only recognize three internested clades: Pan- Carettochelys, Carettochelyidae and Carettochelyinae. A taxonomic review of the group concludes that of 25 named taxa, 13 are nomina valida, 7 are nomina invalida, 3 are nomina dubia, and 2 are nomina nuda

Treatment of displaced intra-articular calcaneal fractures by ligamentotaxis: current concepts’ review

Introduction: A large variety of therapeutic modalities for calcaneal fractures have been described in the literature. No single treatment modality for displaced intra-articular calcaneal fractures has proven superior over the other. This review describes and compares the different percutaneous distractional approaches for intra-articular calcaneal fractures. The history, technique, anatomical and fracture considerations, limitations and the results of different distractional approaches reported in the literature are reviewed. Method: Literature review on different percutaneous distractional approaches for displaced intra-articular calcaneal fractures. Results: Eight studies in which application of a distraction technique was used for the treatment of calcaneal fractures were identified. Because of the use of different classification, techniques, and outcome scoring systems, a meta-analysis was not possible. A literature review reveals overall fair to poor result in 10-29% of patients. Ten up to 26% of patients are unable to return to work after percutaneous treatment of their fracture. A secondary arthrodesis has to be performed in 2-15% of the cases. Infectious complications occur in 2-15%. Some loss of reduction is reported in 4-67%. Conclusion: Percutaneous distractional reduction and fixation appears to be a safe technique with overall good results and an acceptable complication rate, compared with other treatment modalities for displaced intra-articular calcaneal fractures. A meta-analysis, based on Cochrane Library criteria is not possible, because of a lack of level 1 and 2 trials on this subject