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1.
Int J Mol Sci ; 24(9)2023 Apr 22.
Article in English | MEDLINE | ID: mdl-37175400

ABSTRACT

We aimed to investigate whether molecular clues from the extracellular matrix (ECM) can induce oral epithelial differentiation of pluripotent stem cells. Mouse embryonic stem cells (ESC) of the feeder-independent cell line E14 were used as a model for pluripotent stem cells. They were first grown in 2D on various matrices in media containing vitamin C and without leukemia inhibitory factor (LIF). Matrices investigated were gelatin, laminin, and extracellular matrices (ECM) synthesized by primary normal oral fibroblasts and keratinocytes in culture. Differentiation into epithelial lineages was assessed by light microscopy, immunocytochemistry, and flow cytometry for cytokeratins and stem cell markers. ESC grown in 2D on various matrices were afterwards grown in 3D organotypic cultures with or without oral fibroblasts in the collagen matrix and examined histologically and by immunohistochemistry for epithelial (keratin pairs 1/10 and 4/13 to distinguish epidermal from oral epithelia and keratins 8,18,19 to phenotype simple epithelia) and mesenchymal (vimentin) phenotypes. ECM synthesized by either oral fibroblasts or keratinocytes was able to induce, in 2D cultures, the expression of cytokeratins of the stratified epithelial phenotype. When grown in 3D, all ESC developed into two morphologically distinct cell populations on collagen gels: (i) epithelial-like cells organized in islands with occasional cyst- or duct-like structures and (ii) spindle-shaped cells suggestive of mesenchymal differentiation. The 3D culture on oral fibroblast-populated collagen matrices was necessary for further differentiation into oral epithelia. Only ESC initially grown on 2D keratinocyte or fibroblast-synthesized matrices reached full epithelial maturation. In conclusion, ESC can generate oral epithelia under matrix instruction.


Subject(s)
Collagen , Keratinocytes , Animals , Mice , Keratinocytes/metabolism , Epithelium/metabolism , Collagen/metabolism , Extracellular Matrix/metabolism , Embryonic Stem Cells/metabolism , Cell Differentiation , Keratins/metabolism , Fibroblasts/metabolism , Cells, Cultured
2.
BMC Plant Biol ; 21(1): 385, 2021 Aug 20.
Article in English | MEDLINE | ID: mdl-34416864

ABSTRACT

Research in the past decade has demonstrated that a single reference genome is not representative of a species' diversity. MaizeGDB introduces a pan-genomic approach to hosting genomic data, leveraging the large number of diverse maize genomes and their associated datasets to quickly and efficiently connect genomes, gene models, expression, epigenome, sequence variation, structural variation, transposable elements, and diversity data across genomes so that researchers can easily track the structural and functional differences of a locus and its orthologs across maize. We believe our framework is unique and provides a template for any genomic database poised to host large-scale pan-genomic data.


Subject(s)
Data Accuracy , Data Collection/methods , Databases as Topic , Genome, Plant , Genomics , Zea mays/genetics , Genetic Variation
4.
Nucleic Acids Res ; 47(D1): D1146-D1154, 2019 01 08.
Article in English | MEDLINE | ID: mdl-30407532

ABSTRACT

Since its 2015 update, MaizeGDB, the Maize Genetics and Genomics database, has expanded to support the sequenced genomes of many maize inbred lines in addition to the B73 reference genome assembly. Curation and development efforts have targeted high quality datasets and tools to support maize trait analysis, germplasm analysis, genetic studies, and breeding. MaizeGDB hosts a wide range of data including recent support of new data types including genome metadata, RNA-seq, proteomics, synteny, and large-scale diversity. To improve access and visualization of data types several new tools have been implemented to: access large-scale maize diversity data (SNPversity), download and compare gene expression data (qTeller), visualize pedigree data (Pedigree Viewer), link genes with phenotype images (MaizeDIG), and enable flexible user-specified queries to the MaizeGDB database (MaizeMine). MaizeGDB also continues to be the community hub for maize research, coordinating activities and providing technical support to the maize research community. Here we report the changes MaizeGDB has made within the last three years to keep pace with recent software and research advances, as well as the pan-genomic landscape that cheaper and better sequencing technologies have made possible. MaizeGDB is accessible online at https://www.maizegdb.org.


Subject(s)
Computational Biology/methods , Databases, Genetic , Genome, Plant/genetics , Genomics/methods , Zea mays/genetics , Gene Expression Regulation, Plant , Genetic Variation , Information Storage and Retrieval/methods , Internet , Polymorphism, Single Nucleotide , Proteomics/methods , User-Computer Interface , Zea mays/metabolism
5.
Healthc Manage Forum ; 33(6): 259-264, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32666836

ABSTRACT

Although national spending on healthcare has progressed on an upward trend over several decades, issues regarding performance remain. Challenges such as access to specialist care and maternal and infant mortality rates contributed to Canada's recent ranking of ninth among 11 Organisation for Economic Co-operation and Development countries for overall health system performance. Although disruptive transformation is required to resolve our chronic performance issues, effective change cannot be realized without addressing the foundational elements of patient-centred care, interprofessional care, and system integration. Inspired by examples of innovative disruption in other jurisdictions and industries, these three concepts are outlined as the core ingredients for healthcare transformation and describe how they currently function in a paradoxical manner-as self-contradictory statements which in reality are not executed to their true meaning. This article illustrates how improvements in health system performance are hinged to the need to rectify and fuse these three mutually inclusive and inseparable concepts.


Subject(s)
Delivery of Health Care , Patient-Centered Care , Family , Health Facilities , Humans , Infant
6.
Nucleic Acids Res ; 44(D1): D1195-201, 2016 Jan 04.
Article in English | MEDLINE | ID: mdl-26432828

ABSTRACT

MaizeGDB is a highly curated, community-oriented database and informatics service to researchers focused on the crop plant and model organism Zea mays ssp. mays. Although some form of the maize community database has existed over the last 25 years, there have only been two major releases. In 1991, the original maize genetics database MaizeDB was created. In 2003, the combined contents of MaizeDB and the sequence data from ZmDB were made accessible as a single resource named MaizeGDB. Over the next decade, MaizeGDB became more sequence driven while still maintaining traditional maize genetics datasets. This enabled the project to meet the continued growing and evolving needs of the maize research community, yet the interface and underlying infrastructure remained unchanged. In 2015, the MaizeGDB team completed a multi-year effort to update the MaizeGDB resource by reorganizing existing data, upgrading hardware and infrastructure, creating new tools, incorporating new data types (including diversity data, expression data, gene models, and metabolic pathways), and developing and deploying a modern interface. In addition to coordinating a data resource, the MaizeGDB team coordinates activities and provides technical support to the maize research community. MaizeGDB is accessible online at http://www.maizegdb.org.


Subject(s)
Databases, Genetic , Zea mays/genetics , Gene Expression , Genes, Plant , Genetic Variation , Genome, Plant , Metabolic Networks and Pathways , Models, Genetic , Software , User-Computer Interface , Zea mays/metabolism
7.
Development ; 139(14): 2594-603, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22696296

ABSTRACT

To ensure fertility, complex somatic and germinal cell proliferation and differentiation programs must be executed in flowers. Loss-of-function of the maize multiple archesporial cells 1 (mac1) gene increases the meiotically competent population and ablates specification of somatic wall layers in anthers. We report the cloning of mac1, which is the ortholog of rice TDL1A. Contrary to prior studies in rice and Arabidopsis in which mac1-like genes were inferred to act late to suppress trans-differentiation of somatic tapetal cells into meiocytes, we find that mac1 anthers contain excess archesporial (AR) cells that proliferate at least twofold more rapidly than normal prior to tapetal specification, suggesting that MAC1 regulates cell proliferation. mac1 transcript is abundant in immature anthers and roots. By immunolocalization, MAC1 protein accumulates preferentially in AR cells with a declining radial gradient that could result from diffusion. By transient expression in onion epidermis, we demonstrate experimentally that MAC1 is secreted, confirming that the predicted signal peptide domain in MAC1 leads to secretion. Insights from cytology and double-mutant studies with ameiotic1 and absence of first division1 mutants confirm that MAC1 does not affect meiotic cell fate; it also operates independently of an epidermal, Ocl4-dependent pathway that regulates proliferation of subepidermal cells. MAC1 both suppresses excess AR proliferation and is responsible for triggering periclinal division of subepidermal cells. We discuss how MAC1 can coordinate the temporal and spatial pattern of cell proliferation in maize anthers.


Subject(s)
Flowers/growth & development , Flowers/metabolism , Oryza/metabolism , Zea mays/growth & development , Zea mays/metabolism , Cell Proliferation , Flowers/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Reproduction/genetics , Reproduction/physiology , Zea mays/genetics
8.
Article in English | MEDLINE | ID: mdl-38946629

ABSTRACT

Background: Tick-borne encephalitis (TBE) is caused by the tick-borne encephalitis virus (TBEV). TBEV infection can cause symptoms of central nervous system (CNS) inflammation and result in severe consequences including death. TBE is an increasing health threat in the Czech Republic and elsewhere in Europe. In 2020, 23% of 3734 TBE cases reported to the European Centre for Disease Prevention and Control were from the Czech Republic. TBE vaccination is universally recommended in the Czech Republic, but a full analysis of TBE vaccine effectiveness (VE) in the Czech Republic has not been published. Methods: TBE is a notifiable disease in the Czech Republic with mandatory reporting of cases (i.e., laboratory-confirmed TBEV infected patient with symptoms of CNS inflammation) and vaccination history to public health authorities. TBE VE was estimated using the screening method utilizing public health surveillance data from 2018 to 2022 and online household surveys of the general population on TBE vaccine uptake conducted in 2019-2022. Results: In 2018-2022, 3648 TBE cases were reported in the Czech Republic; 98.1% (3105/3166) of TBE cases with known vaccination history were unvaccinated. Among 42,671 persons surveyed from the general population who had known TBE vaccination history, 66.5% were unvaccinated. VE against TBE was 97.6% (95% confidence interval 95.7-98.7). When stratified by age group, VE was 97.1% (88.4-99.3) in 1-15 years of age, 97.9% (95.3-99.0) in 16-59 years of age, and 96.9% (90.5-99.0) in ≥60 years of age. TBE vaccination averted an estimated 1020 TBE cases in the Czech Republic from 2018 to 2022. Conclusions: This first published study with a full analysis of TBE VE in the Czech Republic showed that vaccination was highly effective for the prevention of TBE including in children, an age group with increasing TBE disease burden. Vaccination averted hundreds of TBE cases and hospitalizations despite the relatively low compliance with TBE vaccine recommendations. To prevent additional TBE cases in the Czech Republic, enhanced efforts to increase TBE vaccine uptake are needed.

9.
Genetics ; 224(1)2023 05 04.
Article in English | MEDLINE | ID: mdl-36755109

ABSTRACT

Protein structures play an important role in bioinformatics, such as in predicting gene function or validating gene model annotation. However, determining protein structure was, until now, costly and time-consuming, which resulted in a structural biology bottleneck. With the release of such programs AlphaFold and ESMFold, this bottleneck has been reduced by several orders of magnitude, permitting protein structural comparisons of entire genomes within reasonable timeframes. MaizeGDB has leveraged this technological breakthrough by offering several new tools to accelerate protein structural comparisons between maize and other plants as well as human and yeast outgroups. MaizeGDB also offers bulk downloads of these comparative protein structure data, along with predicted functional annotation information. In this way, MaizeGDB is poised to assist maize researchers in assessing functional homology, gene model annotation quality, and other information unavailable to maize scientists even a few years ago.


Subject(s)
User-Computer Interface , Zea mays , Humans , Zea mays/genetics , Zea mays/metabolism , Databases, Genetic , Computational Biology/methods , Genome, Plant , Molecular Sequence Annotation , Genomics/methods
10.
Article in English | MEDLINE | ID: mdl-37422077

ABSTRACT

OBJECTIVES: Tick-borne encephalitis (TBE) is an infection by the tick-borne encephalitis virus (TBEV) that results in symptoms of central nervous system inflammation. TBE is endemic in Latvia and other European countries. TBE vaccines are commonly used in Latvia, but vaccine effectiveness estimates are limited. METHODS: Study staff at Riga Stradins University conducted nationwide active surveillance for TBEV infections. Serum and cerebrospinal fluid were ELISA-tested for TBEV-specific IgG and IgM antibodies. Vaccination history was collected by interview and medical record review. Utilizing data from surveillance and population surveys, vaccine effectiveness (with 95% CIs) and cases averted were estimated using the screening method. RESULTS: There were 587 laboratory-identified TBE cases from 2018 to 2020; 98.1% (576/587) were unvaccinated, 1.5% (9/587) were unknown or partially vaccinated, and 0.3% (2/587) were fully vaccinated (three-dose primary series and appropriately timed boosters). TBE resulted in the death of 1.7% (10/587) of TBE cases. TBE vaccine history was ascertained from 92.0% (13 247/14 399) people from the general population: 38.6% (5113/13 247) were unvaccinated, 26.3% (3484/13 247) were fully vaccinated, and 35.1% (4650/13 247) were partially vaccinated. TBE vaccine effectiveness was 99.5% (98.0-99.9) against TBE, 99.5% (97.9-99.9) against TBE hospitalization, 99.3% (94.8-99.9) against moderate/severe TBE, and 99.2% (94.4-99.9) against TBE hospitalization >12 days. From 2018 to 2020, vaccination averted 906 TBE cases, including 20 deaths. DISCUSSION: TBE vaccine was highly effective in preventing TBE, moderate and severe disease, and prolonged hospitalization. To prevent life-threatening TBE, TBE vaccine uptake and compliance should be increased in Latvia and other European regions where TBE is endemic.

11.
Pediatr Infect Dis J ; 42(10): 927-931, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37406220

ABSTRACT

BACKGROUND: Tick-borne encephalitis (TBE) is an infection by the tick-borne encephalitis virus (TBEV) with symptoms of central nervous system inflammation. TBE is endemic in Latvia and other parts of Europe. TBE vaccination is recommended for children in Latvia. TBE vaccine effectiveness (VE) was estimated in Latvia, a country with high TBE incidence, providing the first VE estimates against a range of TBEV infection outcomes in children 1-15 years-of-age. METHODS: Riga Stradins University conducted nationwide surveillance for suspected TBE cases. Serum and cerebrospinal fluid were ELISA tested for TBEV-specific IgG and IgM antibodies. A fully vaccinated child was an individual who had received the 3-dose primary series and appropriately timed boosters. The proportion of laboratory-confirmed TBE cases fully vaccinated (PCV) was determined from interviews and medical records. The proportion of the general population fully vaccinated (PPV) was determined from national surveys conducted in 2019 and 2020. TBE VE in children 1-15 years-of-age was estimated using the screening method: VE = 1 - [PCV/(1 - PCV)/PPV/(1 - PPV)]. RESULTS: From 2018 to 2020, surveillance identified 36 TBE cases in children 1-15 years-of-age; all were hospitalized, 5 (13.9%) for >12 days. Of the TBE cases, 94.4% (34/36) were unvaccinated compared with 43.8% of children in the general population. VE against TBE hospitalization in children 1-15 years-of-age was 94.9% (95% confidence interval 63.1-99.3). In 2018-2020, vaccination in children 1-15 years-of-age averted 39 hospitalized TBE cases. CONCLUSION: Pediatric TBE vaccines were highly effective in preventing TBE in children. Increasing TBE vaccine uptake in children is essential to maximize the public health impact of TBE vaccination.


Subject(s)
Encephalitis Viruses, Tick-Borne , Encephalitis, Tick-Borne , Vaccines , Viral Vaccines , Humans , Child , Encephalitis, Tick-Borne/epidemiology , Encephalitis, Tick-Borne/prevention & control , Latvia/epidemiology , Europe , Vaccination
12.
BMJ Open ; 13(12): e070903, 2023 12 10.
Article in English | MEDLINE | ID: mdl-38072499

ABSTRACT

INTRODUCTION: Lyme disease (LD) is the most frequent tick-borne disease in the moderate climates of Europe. This study will inform the phase III efficacy study for Pfizer and Valneva's investigational Lyme disease vaccine, VLA15. VLA15 phase III will be conducted in the USA and Europe due to the vaccine's serotype coverage and public health burden of LD. In Europe, the existence and location of sites that have access to populations with high LD annual incidence is uncertain. This active, prospective surveillance study assesses annual LD incidence at general practice (GP)/primary care sites, allowing for phase III site vetting and better characterisation of LD burden in selected regions for study size calculations. METHODS AND ANALYSIS: This burden of Lyme disease (BOLD) study will assess LD incidence overall and by site at 15 GP/primary care practices in endemic areas of 6 European countries from Spring 2021 to December 2022 and will be summarised with counts (n), percentages (%) and associated 95% CIs. Suspected LD cases identified from site's practice panels are documented on screening logs, where clinical LD manifestations, diagnoses and standard of care diagnostic results are recorded. In the initial 12-month enrolment phase, suspected LD cases are offered enrolment. Participants undergo interview and clinical assessments to establish medical history, final clinical diagnosis, clinical manifestations and quality of life impact. Study-specific procedures include LD serology, skin punch biopsies and Lyme manifestation photographs. For every enrolled participant diagnosed with LD, 6-10 age-matched controls are randomly selected and offered enrolment for an embedded LD risk factor analysis. Persistent symptoms or post-treatment LD will be assessed at follow-up visits up to 2 years after initial diagnosis, while patients remain symptomatic. ETHICS AND DISSEMINATION: This study has been approved by all sites' local ethics committees. The results will be presented at conferences and published in peer-reviewed journals.


Subject(s)
Lyme Disease , Quality of Life , Humans , Europe/epidemiology , Incidence , Lyme Disease/diagnosis , Lyme Disease/epidemiology , Lyme Disease/prevention & control , Primary Health Care , Prospective Studies , Watchful Waiting , Clinical Trials, Phase III as Topic
13.
Emerg Microbes Infect ; 12(2): 2278898, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37906509

ABSTRACT

Tick-borne encephalitis (TBE) is an infection of the central nervous system caused by the tick-borne encephalitis virus (TBEV). TBE is endemic in parts of Europe and Asia. TBEV is transmitted to humans primarily by Ixodes ticks. There have been 5 TBE cases identified in Japan, all on the northern island of Hokkaido. Rodents with TBEV antibodies and Ixodes ticks have been identified throughout Japan, indicating that TBEV infection might be undiagnosed in Japan. Residual serum and cerebrospinal fluid (CSF) collected in 2010-2021 from 520 patients ≥1 year-of-age previously hospitalized with encephalitis or meningitis of unknown etiology at 15 hospitals (including 13 hospitals outside of Hokkaido) were screened by ELISA for TBEV IgG and IgM antibodies; TBEV infection was confirmed by the gold standard neutralization test. Residual serum was available from 331 (63.6%) patients and CSF from 430 (82.6%) patients; both serum and CSF were available from 189 (36.3%). Two patients were TBE cases: a female aged 61 years hospitalized for 104 days in Oita (2000 km south of Hokkaido) and a male aged 24 years hospitalized for 11 days in Tokyo (1200 km south of Hokkaido). Retrospective testing also identified a previous TBEV infection in a female aged 45 years hospitalized for 12 days in Okayama (1700 km south of Hokkaido). TBEV infection should be considered as a potential cause of encephalitis or meningitis in Japan. TBE cases are likely undiagnosed in Japan, including outside of Hokkaido, due to limited clinical awareness and lack of availability of TBE diagnostic tests.


Subject(s)
Encephalitis Viruses, Tick-Borne , Encephalitis, Tick-Borne , Ixodes , Meningitis , Animals , Humans , Male , Female , Encephalitis, Tick-Borne/diagnosis , Encephalitis, Tick-Borne/epidemiology , Japan/epidemiology , Retrospective Studies
14.
Proc Natl Acad Sci U S A ; 106(9): 3603-8, 2009 Mar 03.
Article in English | MEDLINE | ID: mdl-19204280

ABSTRACT

Molecular mechanisms that initiate meiosis have been studied in fungi and mammals, but little is known about the mechanisms directing the meiosis transition in other organisms. To elucidate meiosis initiation in plants, we characterized and cloned the ameiotic1 (am1) gene, which affects the transition to meiosis and progression through the early stages of meiotic prophase in maize. We demonstrate that all meiotic processes require am1, including expression of meiosis-specific genes, establishment of the meiotic chromosome structure, meiosis-specific telomere behavior, meiotic recombination, pairing, synapsis, and installation of the meiosis-specific cytoskeleton. As a result, in most am1 mutants premeiotic cells enter mitosis instead of meiosis. Unlike the genes involved in initiating meiosis in yeast and mouse, am1 also has a second downstream function, whereby it regulates the transition through a novel leptotene-zygotene checkpoint, a key step in early meiotic prophase. The am1 gene encodes a plant-specific protein with an unknown biochemical function. The AM1 protein is diffuse in the nucleus during the initiation of meiosis and then binds to chromatin in early meiotic prophase I when it regulates the leptotene-zygotene progression.


Subject(s)
Meiosis , Miotics , Plant Proteins/metabolism , Zea mays/cytology , Zea mays/metabolism , Alleles , Chromosomes/genetics , Gene Expression Regulation, Plant , Mutation/genetics , Phylogeny , Plant Proteins/genetics , Telomere/genetics , Zea mays/genetics
15.
Front Plant Sci ; 13: 787703, 2022.
Article in English | MEDLINE | ID: mdl-35769295

ABSTRACT

Crop wild relatives represent valuable reservoirs of variation for breeding, but their populations are threatened in natural habitats, are sparsely represented in genebanks, and most are poorly characterized. The focus of this study is the Oryza rufipogon species complex (ORSC), wild progenitor of Asian rice (Oryza sativa L.). The ORSC comprises perennial, annual and intermediate forms which were historically designated as O. rufipogon, O. nivara, and O. sativa f. spontanea (or Oryza spp., an annual form of mixed O. rufipogon/O. nivara and O. sativa ancestry), respectively, based on non-standardized morphological, geographical, and/or ecologically-based species definitions and boundaries. Here, a collection of 240 diverse ORSC accessions, characterized by genotyping-by-sequencing (113,739 SNPs), was phenotyped for 44 traits associated with plant, panicle, and seed morphology in the screenhouse at the International Rice Research Institute, Philippines. These traits included heritable phenotypes often recorded as characterization data by genebanks. Over 100 of these ORSC accessions were also phenotyped in the greenhouse for 18 traits in Stuttgart, Arkansas, and 16 traits in Ithaca, New York, United States. We implemented a Bayesian Gaussian mixture model to infer accession groups from a subset of these phenotypic data and ascertained three phenotype-based group assignments. We used concordance between the genotypic subpopulations and these phenotype-based groups to identify a suite of phenotypic traits that could reliably differentiate the ORSC populations, whether measured in tropical or temperate regions. The traits provide insight into plant morphology, life history (perenniality versus annuality) and mating habit (self- versus cross-pollinated), and are largely consistent with genebank species designations. One phenotypic group contains predominantly O. rufipogon accessions characterized as perennial and largely out-crossing and one contains predominantly O. nivara accessions characterized as annual and largely inbreeding. From these groups, 42 "core" O. rufipogon and 25 "core" O. nivara accessions were identified for domestication studies. The third group, comprising 20% of our collection, has the most accessions identified as Oryza spp. (51.2%) and levels of O. sativa admixture accounting for more than 50% of the genome. This third group is potentially useful as a "pre-breeding" pool for breeders attempting to incorporate novel variation into elite breeding lines.

16.
Bioinformatics ; 26(3): 434-6, 2010 Feb 01.
Article in English | MEDLINE | ID: mdl-20124413

ABSTRACT

SUMMARY: Methods to automatically integrate sequence information with physical and genetic maps are scarce. The Locus Lookup tool enables researchers to define windows of genomic sequence likely to contain loci of interest where only genetic or physical mapping associations are reported. Using the Locus Lookup tool, researchers will be able to locate specific genes more efficiently that will ultimately help them develop a better maize plant. With the availability of the well-documented source code, the tool can be easily adapted to other biological systems. AVAILABILITY: The Locus Lookup tool is available on the web at http://maizegdb.org/cgi-bin/locus_lookup.cgi. It is implemented in PHP, Oracle and Apache, with all major browsers supported. Source code is freely available for download at http://ftp.maizegdb.org/open_source/locus_lookup/.


Subject(s)
Computational Biology/methods , Genome, Plant , Software , Zea mays/genetics , Databases, Genetic , Internet , Sequence Analysis, DNA , User-Computer Interface
17.
J Oral Pathol Med ; 40(2): 143-52, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21138479

ABSTRACT

Increasing evidence indicates that cancer growth is driven by a sub-population of self-renewing cancer stem cells (CSCs) and that clinical problems of tumor recurrence after therapy may be related to differential resistance of CSCs to therapeutic elimination. Fanconi anemia (FA) is an autosomal recessive disorder associated with deficiencies of DNA repair and a greatly enhanced risk of hematopoietic malignancies and of head and neck squamous cell carcinoma (HNSCC). In FA patients, lack of DNA repair complicates therapies acting through DNA damage and alternative approaches, such as targeting signaling pathways associated with stem cell maintenance, might be of particular benefit. To assess effects of FA gene defects on the expression of stem cell properties, CSC patterns in cell lines derived from FA-related and sporadic HNSCC were compared. As for sporadic cell lines, FA cell lines showed colony morphologies associated with stem cell patterns. In all cell lines, cells with strong staining for CD44 (CD44(high) ) showed lower rates of apoptosis and a greater DNA damage induced block in the G2 phase of the cell cycle than CD44(low) cells. Mitomycin C, and UVB increased overall rates of apoptosis for both sporadic and FA cell lines, although FA cells tended to be more sensitive to apoptotic induction. Fluorescence activated cell sorting, immunohistochemistry, and QPCR indicated distinctly different patterns of gene expression of CD44(high) and CD44(low) cells in both sporadic and FA cell lines.


Subject(s)
Carcinoma, Squamous Cell/pathology , Fanconi Anemia/complications , Gene Expression Regulation, Neoplastic , Head and Neck Neoplasms/pathology , Neoplastic Stem Cells/pathology , Apoptosis/genetics , Carcinoma, Squamous Cell/complications , Carcinoma, Squamous Cell/genetics , Cell Line, Tumor , DNA Damage/genetics , Drug Resistance, Neoplasm , Fanconi Anemia/genetics , G2 Phase/genetics , Head and Neck Neoplasms/complications , Head and Neck Neoplasms/genetics , Humans , Hyaluronan Receptors/biosynthesis , Hyaluronan Receptors/genetics
18.
BMC Cancer ; 10: 166, 2010 Apr 28.
Article in English | MEDLINE | ID: mdl-20426848

ABSTRACT

BACKGROUND: Subsets of cells with stem-like properties have been previously isolated from human epithelial cancers and their resistance to apoptosis-inducing stimuli has been related to carcinoma recurrence and treatment failure. The aim of this study was to investigate the mechanisms of resistance to apoptosis-inducing agents of cells with stem-like properties in both normal and malignant human epithelia. METHODS: Cells isolated from fresh human head and neck carcinomas (n = 11), cell lines derived from head and neck, prostate and breast human carcinomas (n = 7), and from normal human oral mucosa (n = 5), were exposed to various apoptosis-inducing stimuli (UV, Tumour Necrosis Factor, Cisplatin, Etoposide, and Neocarzinostatin). Flow cytometry for CD44 and epithelial-specific antigen (ESA) expression, colony morphology, tumour sphere formation and rapid adherence assays were used to identify the subset of cells with stem-like properties. Apoptosis, cell cycle and expression of various cell cycle checkpoint proteins were assessed (Western Blot, qPCR). The role of G2-checkpoint regulators Chk1 and Chk2 was investigated by use of debromohymenialdisine (DBH) and siRNA. RESULTS: In both cancer biopsies and carcinoma cell lines a subset of CD44(high) cells showed increased clonogenicity, a significantly lower rate of apoptosis, and a significantly higher proportion of cells in the G2-phase of the cell cycle. An inverse correlation between the percentage of cells in G2-phase and the rate of apoptosis was found. Pulse-chase with iododeoxyuridine (IdU) demonstrated that CD44(high) carcinoma cells spent longer time in G2, even in un-treated controls. These cells expressed higher levels of G2 checkpoint proteins, and their release from G2 with BDH or Chk1 siRNA increased their rate of apoptosis. Low passage cultures of normal keratinocytes were also found to contain a subset of CD44(high) cells showing increased clonogenicity, and a similar pattern of G2-block associated with apoptotic resistance. CONCLUSIONS: These data indicate that both normal and malignant human epithelial cells with stem-like properties show greater resistance to apoptosis associated with extended G2 cell cycle phase, and that this property is not a consequence of neoplastic transformation. Targeting G2 checkpoint proteins releases these cells from the G2-block and makes them more prone to apoptosis, implying an opportunity for improved therapeutic approaches.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis , Drug Resistance, Neoplasm , G2 Phase , Neoplastic Stem Cells/pathology , Radiation Tolerance , Ultraviolet Rays , Apoptosis/drug effects , Apoptosis/radiation effects , Cell Adhesion/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Shape/drug effects , Cisplatin/pharmacology , Dose-Response Relationship, Drug , Etoposide/pharmacology , G2 Phase/drug effects , G2 Phase/radiation effects , Humans , Hyaluronan Receptors/metabolism , Keratinocytes/drug effects , Keratinocytes/pathology , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/radiation effects , Time Factors , Tumor Cells, Cultured , Tumor Necrosis Factor-alpha/pharmacology , Zinostatin/pharmacology
19.
Disabil Rehabil ; 42(2): 267-273, 2020 01.
Article in English | MEDLINE | ID: mdl-30277412

ABSTRACT

Background: The evolution of healthcare in Ukraine has been impacted by a number of factors, including years of communist control followed by the birth of an emerging democracy and most recently, conflict in the eastern part of the country. Rehabilitation is an aspect of Ukraine's healthcare system that is still heavily influenced by the Soviet-era mentality of perfectionism.Methods: This article presents the results of a qualitative research study that undertook 13 key informant interviews to answer the question of what can be learned from the perspectives of individuals in Ukraine or with experience working in Ukraine with respect to developing and implementing appropriate rehabilitation that is inclusive and targets health equity.Results: Key themes that informants determined will affect the future of rehabilitation in Ukraine include the current health care structure, the culture surrounding disability, international and domestic sources of involvement, and a revised curriculum for new and existing rehabilitation professionals.Conclusions: The input from these individuals, supported by evidence from the literature, provides a foundational understanding of the currently fragmented rehabilitation system in Ukraine and the factors that professionals prioritize as integral components of an infrastructure that supports rehabilitation in the twenty-first century.Implications for RehabilitationWhile the recent conflict in Eastern Ukraine has served as a lightning rod to shed light on the lack of resources allocated toward disability and chronic care in the region, rehabilitation is also lacking in the general population, requiring a response that addresses the unique needs of a population of over 44 million individuals.Alongside a curriculum that complies with international accreditation standards, an influx of job and career opportunities developed by the government is needed to encourage individuals to work in the rehabilitation sector.A nation-wide strategy must be developed to disseminate knowledge about disability and rehabilitation in order to begin to address the issues of social exclusion and stigma associated with disability in many post-Soviet countries.


Subject(s)
Delivery of Health Care , Disabled Persons/rehabilitation , Rehabilitation , Curriculum , Humans , Social Stigma , Ukraine
20.
Nucleic Acids Res ; 35(Database issue): D895-900, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17202174

ABSTRACT

MaizeGDB is the Maize Genetics and Genomics Database. Available at MaizeGDB are diverse data that support maize research including maps, gene product information, loci and their various alleles, phenotypes (both naturally occurring and as a result of directed mutagenesis), stocks, sequences, molecular markers, references and contact information for maize researchers worldwide. Also available through MaizeGDB are various community support service bulletin boards including the Editorial Board's list of high-impact papers, information about the Annual Maize Genetics Conference and the Jobs board where employment opportunities are posted. Reported here are data updates, improvements to interfaces and changes to standard operating procedures that have been made during the past 2 years. MaizeGDB is freely available and can be accessed online at http://www.maizegdb.org.


Subject(s)
Databases, Genetic , Zea mays/genetics , Chromosome Mapping , Genomics , Internet , User-Computer Interface
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