The Wharton's jelly of the umbilical cord contains mucoid connective tissue and fibroblast-like cells. Using flow cytometric analysis, we found that mesenchymal cells isolated from the umbilical cord express matrix receptors (CD44, CD105) and integrin markers (CD29, CD51) but not hematopoietic lineage markers (CD34, CD45). Interestingly, these cells also express significant amounts of mesenchymal stem cell markers (SH2, SH3). We therefore investigated the potential of these cells to differentiate into cardiomyocytes by treating them with 5-azacytidine or by culturing them in cardiomyocyteconditioned medium and found that both sets of conditions resulted in the expression of cardiomyocyte markers, namely N-cadherin and cardiac troponin I. We also showed that these cells have multilineage potential and that, under suitable culture conditions, are able to differentiate into cells of the adipogenic and osteogenic lineages. These findings may have a significant impact on studies of early human cardiac differentiation, functional genomics, pharmacological testing, cell therapy, and tissue engineering by helping to eliminate worrying ethical and technical issues.
Perylene-3,4,9,10-tetracarboxylic acid diimides (perylene diimides, PDIs) have been used as industrial pigments for many years. More recently, new applications for PDI derivatives have emerged in areas including organic photovoltaic devices and field-effect transistors. This Perspective discusses the synthesis and physical properties of PDI derivatives and their applications in organic electronics.
In order to effectively study the population experiencing insomnia, it is important to identify reliable and valid tools to measure sleep that can be administered in the home setting. The purpose of this study was to assess psychometric properties for the Chinese version of the Pittsburgh Sleep Quality Index (CPSQI) in community-dwelling adults with primary insomnia. The CPSQI had an overall reliability coefficient of 0.82 -0.83 for all subjects. "Subjective sleep quality" was the component most highly correlated with the global score. Overall, the CPSQI showed acceptable test-retest reliability over a 14- to 21-day interval with a coefficient of 0.85 for all subjects and 0.77 for primary insomniacs. The two contrasting groups had significantly different global and component scores. A CPSQI of greater than 5 yielded a sensitivity and specificity of 98 and 55% in primary insomniacs vs. controls. A CPSQI of greater than 6 resulted in a sensitivity and specificity of 90 and 67%. Results suggest that the CPSQI is a psychometrically sound measure of sleep quality and disturbance for patients with primary insomnia. It may not be an effective screening tool because of its low specificity, but it can be a sensitive, reliable, and valid outcome assessment tool for use in community-based studies of primary insomnia.
The normal microflora of the skin includes staphylococcal species that will induce inflammation when present below the dermis but are tolerated on the epidermal surface without initiating inflammation. Here we reveal a previously unknown mechanism by which a product of staphylococci inhibits skin inflammation. This inhibition is mediated by staphylococcal lipoteichoic acid (LTA), and acts selectively on keratinocytes triggered through Toll-like receptor (TLR) 3. The significance of this is seen by observations that TLR3 activation is required for normal inflammation after injury, and that keratinocytes require TLR3 to respond to RNA from damaged cells with the release of inflammatory cytokines. Staphylococcal LTA inhibits both inflammatory cytokine release from keratinocytes and inflammation triggered by injury through a TLR2-dependent mechanism. These findings show for the first time that the skin epithelium requires TLR3 for normal inflammation after wounding and that the microflora can modulate specific cutaneous inflammatory responses.
SARS-CoV-2-specific antibodies, particularly those preventing viral spike receptor binding domain (RBD) interaction with host angiotensin-converting enzyme 2 (ACE2) receptor, can neutralize the virus. It is, however, unknown which features of the serological response may affect clinical outcomes of COVID-19 patients. We analyzed 983 longitudinal plasma samples from 79 hospitalized COVID-19 patients and 175 SARS-CoV-2-infected outpatients and asymptomatic individuals. Within this cohort, 25 patients died of their illness. Higher ratios of IgG antibodies targeting S1 or RBD domains of spike compared to nucleocapsid antigen were seen in outpatients who had mild illness versus severely ill patients. Plasma antibody increases correlated with decreases in viral RNAemia, but antibody responses in acute illness were insufficient to predict inpatient outcomes. Pseudovirus neutralization assays and a scalable ELISA measuring antibodies blocking RBD-ACE2 interaction were well correlated with patient IgG titers to RBD. Outpatient and asymptomatic individuals’ SARS-CoV-2 antibodies, including IgG, progressively decreased during observation up to five months post-infection.
This review focuses on the development of nanoparticle systems for antimicrobial drug delivery. Numerous antimicrobial drugs have been prescribed to kill or inhibit the growth of microbes such as bacteria, fungi and viruses. Even though the therapeutic efficacy of these drugs has been well established, inefficient delivery could result in inadequate therapeutic index and local and systemic side effects including cutaneous irritation, peeling, scaling and gut flora reduction. Nanostructured biomaterials, nanoparticles in particular, have unique physicochemical properties such as ultra small and controllable size, large surface area to mass ratio, high reactivity, and functionalizable structure. These properties can be applied to facilitate the administration of antimicrobial drugs, thereby overcoming some of the limitations in traditional antimicrobial therapeutics. In recent years, encapsulation of antimicrobial drugs in nanoparticle systems has emerged as an innovative and promising alternative that enhances therapeutic effectiveness and minimizes undesirable side effects of the drugs. Here the current progress and challenges in synthesizing nanoparticle platforms for delivering various antimicrobial drugs are reviewed. We also call attention to the need to unite the shared interest between nanoengineers and microbiologists in developing nanotechnology for the treatment of microbial diseases.
In order to study the differential protein expression in complex biological samples, strategies for rapid, highly reproducible and accurate quantification are necessary. Isotope labeling and fluorescent labeling techniques have been widely used in quantitative proteomics research. However, researchers are increasingly turning to label-free shotgun proteomics techniques for faster, cleaner, and simpler results. Mass spectrometry-based label-free quantitative proteomics falls into two general categories. In the first are the measurements of changes in chromatographic ion intensity such as peptide peak areas or peak heights. The second is based on the spectral counting of identified proteins. In this paper, we will discuss the technologies of these label-free quantitative methods, statistics, available computational software, and their applications in complex proteomics studies.
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