392 research outputs found
The current state of optometric education worldwide
Optometric practice has been shown to vary greatly between countries. Previous data has suggested much disparity between the level of optometric education and the scope of practice. There currently exists no comprehensive comparative data on the standards · and scope of optometric education throughout the world. The goal of this project was to establish such a data source. A two-tiered survey was sent to various countries to establish a comprehensive computer database describing optometric education at vanous institutions and numerous countries worldwide. The general scope of optometric education is summarized for each country
A Partial Catalog of Proteins Secreted by Epidermal Keratinocytes in Culture
Proteins secreted by epidermal keratinocytes are known to engage in functions other than those directly associated with barrier formation. We have used a previously published culture model to collect proteins secreted by adult human epidermal keratinocytes. Electrophoresis and microsequencing allowed us to identify 20 proteins. The list of proteins includes those known to be produced by keratinocytes (β-2 microglobulin, βIG-H3, calgranulin A, cathepsin B and D, E-cadherin, gelatinase B, gelsolin, interstitial collagenase, laminin B2t, plasminogen activator inhibitor-1, protein 14–3-3ε, SCC antigen, stratifin, and translationally controlled tumor protein) as well as those not previously known to be secreted by keratinocytes (epididymis secretory protein, maspin, and anti-neoplastic urinary protein). In addition, two proteins were identified that are not known to be secreted (glutathione-S-transferase and heat shock protein 27/28 kDa). The varied nature of the proteins identified suggests that epidermal keratinocytes have physiologic functions that have yet to be identified
Retrovirus-Mediated Transduction of Cultured Epidermal Keratinocytes
Retrovirus-mediated gene transfer is an efficient means of introducing and expressing exogenous gene(s) in many cell types including keratinocytes. However, parameters of transduction and gene expression have not been systematically analyzed for keratinocytes. To carry out such a study we have transduced cultures of newborn foreskin cells with retroviral vectors that encode the genes for neomycin resistance (neor) and for beta-galactosidase (B-gal). The neor gene is a dominant selectable marker and the B-gal gene encodes a histochemically detectable product. Our key findings are the following: 1) all keratinocytes that form colonies can be successfully transduced at a viral titer greater than 5 × 106 colony-forming units/ml; 2) transduction is effected by integration of a single copy of retroviral DNA; 3) transduced cells are not at a growth disadvantage and, in fact, single clones of transduced keratinocytes can be expanded to yield over 109 cells, suggesting that stem cells are transduced; 4) whereas most transduced colonies exhibit B-gal staining in a high percentage of constituent cells, some colonies had a mosaic or sectored staining pattern; 5) expression of the non-selectable B-gal gene was somewhat greater in differentiated cells of the culture as compared to nondifferentiated precursors. The ability to transduce stem cells at a high efficiency and to follow expression of transduced genes in clonal progeny will allow lineage mapping in stratified epithelial tissues
Synthesis and Secretion of Apolipoprotein E by Cultured Human Keratinocytes
Non-polar lipids are synthesized by keratinocytes in the epidermis and transported to the extracellular space where they contribute to formation of a permeability barrier. Transport of non-polar lipids in other organs and tissues usually occurs with the lipid complexed to an apolipoprotein. In this study we set out to learn if apolipoprotein E is produced by human epidermal keratinocytes in culture. Analysis of tota' cellular RNA from cultured keratinocytes showed the presence of human apolipoprotein E mRNA at concentrations ranging from 2.5 to 35 molecules/cell. The cells secrete a protein identified as apo E on the basis of molecular weight, isoform pattern, and immunoreactivity. Enzyme linked immunosorbent assay of media from keratinocyte cultures indicated that apolipoprotein E is secreted at a rate of 0.92 ng/h/106 cells
Epithelium-specific Response of Cultured Keratinocytes to Infection with Adenovirus Type 2
Adenoviruses are pathogenic for certain stratified squamous epithelia. The sites most frequently involved are the upper respiratory tract and oropharynx. Adenovirus infections of the epidermis are quite rare. We examined the virus-cell interactions of adenovirus type 2 (Ad2) and cultured human keratinocytes grown from a variety of body sites. Our intent was to explore the nature of the apparent epithelium-specific susceptibility to Ad2. In brief, we found that in vitro viral susceptibility of the keratinocytes could be reliably predicted based on whether the cells originated from an epidermal or oropharyngeal surface. Ad2 proceeded through a complete vegetative cycle when used to infect cultured keratinocytes from oropharyngeal sites (e.g., gingiva and soft palate). In contrast, Ad2 infection was severely restricted in keratinocytes from epidermal sites (e.g., foreskin, abdomen, and buttock). These results demonstrate that the in vitro response to infection with Ad2 reflects in vivo tissue-specific susceptibility. In vivo, cervical epithelium is rarely infected with Ad2 and yet in culture, cervical keratinocytes were fully permissive for Ad2 replication. We propose that the permissive or nonpermissive response to Ad2 may be regulated by a particular aspect of cell phenotype. Because the permissive responses seen in this study were all generated in keratinocytes from mucosal sites, it is possible the in vitro response to Ad2 reflects inherent differences between mucosal and epidermal keratinocytes
Prostate Cancer Stem Cell-Targeted Efficacy of a New-Generation Taxoid, SBT-1214 and Novel Polyenolic Zinc-Binding Curcuminoid, CMC2.24
Background
Prostate cancer is the second leading cause of cancer death among men. Multiple evidence suggests that a population of tumor-initiating, or cancer stem cells (CSCs) is responsible for cancer development and exceptional drug resistance, representing a highly important therapeutic target. The present study evaluated CSC-specific alterations induced by new-generation taxoid SBT-1214 and a novel polyenolic zinc-binding curcuminoid, CMC2.24, in prostate CSCs. Principal Findings
The CD133high/CD44high phenotype was isolated from spontaneously immortalized patient-derived PPT2 cells and highly metastatic PC3MM2 cells. Weekly treatment of the NOD/SCID mice bearing PPT2- and PC3MM3-induced tumors with the SBT-1214 led to dramatic suppression of tumor growth. Four of six PPT2 and 3 of 6 PC3MM2 tumors have shown the absence of viable cells in residual tumors. In vitro, SBT-1214 (100nM-1µM; for 72 hr) induced about 60% cell death in CD133high/CD44+/high cells cultured on collagen I in stem cell medium (in contrast, the same doses of paclitaxel increased proliferation of these cells). The cytotoxic effects were increased when SBT-1214 was combined with the CMC2.24. A stem cell-specific PCR array assay revealed that this drug combination mediated massive inhibition of multiple constitutively up-regulated stem cell-related genes, including key pluripotency transcription factors. Importantly, this drug combination induced expression of p21 and p53, which were absent in CD133high/CD44high cells. Viable cells that survived this treatment regimen were no longer able to induce secondary spheroids, exhibited significant morphological abnormalities and died in 2-5 days. Conclusions
We report here that the SBT-1214 alone, or in combination with CMC2.24, possesses significant activity against prostate CD133high/CD44+/high tumor-initiating cells. This drug combination efficiently inhibits expression of the majority of stem cell-related genes and pluripotency transcription factors. In addition, it induces a previously absent expression of p21 and p53 (“gene wake-up”), which can potentially reverse drug resistance by increasing sensitivity to anti-cancer drugs
TIA1 Mutations in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia Promote Phase Separation and Alter Stress Granule Dynamics.
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are age-related neurodegenerative disorders with shared genetic etiologies and overlapping clinical and pathological features. Here we studied a novel ALS/FTD family and identified the P362L mutation in the low-complexity domain (LCD) of T cell-restricted intracellular antigen-1 (TIA1). Subsequent genetic association analyses showed an increased burden of TIA1 LCD mutations in ALS patients compared to controls (p = 8.7 × 1
An Exploration of the Paradigm for the 2-3 Hour Period Gap in Cataclysmic Variables
We critically examine the basic paradigm for the origin of the 2-3 hr period
gap in cataclysmic variables (CVs). We carry out an extensive population
synthesis study of CVs starting from ~ 3 x 10^6 primordial binaries, and
evolving some ~ 2 x 10^4 surviving systems through their CV phase. In
particular we study current-epoch distributions of CVs in the ,
R_{2}-P_{orb}, M_{2}-P_{orb}, q-P_{orb}, T_{eff}-P_{orb}, and L_{2}-P_{orb}
planes, where is the mass transfer rate, q is the mass ratio M_2/M_1,
and M_2, R_2, T_{eff}, and L_2 are the donor star mass, radius, effective
temperature, and luminosity, respectively. This work presents a new perspective
on theoretical studies of the long-term evolution of CVs. In particular, we
show that if the current paradigm is correct, the secondary masses in CVs just
above the period gap should be as much as ~ 50% lower than would be inferred if
one assumes a main-sequence radius-mass relation for the donor star.Comment: Accepted in Ap
Therapy development for the mucopolysaccharidoses : updated consensus recommendations for neuropsychological endpoints
Neurological dysfunction represents a significant clinical component of many of the mucopolysaccharidoses (also known as MPS disorders). The accurate and consistent assessment of neuropsychological function is essential to gain a greater understanding of the precise natural history of these conditions and to design effective clinical trials to evaluate the impact of therapies on the brain. In 2017, an International MPS Consensus Panel published recommendations for best practice in the design and conduct of clinical studies investigating the effects of therapies on cognitive function and adaptive behavior in patients with neuronopathic mucopolysaccharidoses. Based on an International MPS Consensus Conference held in February 2020, this article provides updated consensus recommendations and expands the objectives to include approaches for assessing behavioral and social-emotional state, caregiver burden and quality of life in patients with all mucopolysaccharidoses
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