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1.
Wound Manag Prev ; 68(4): 14-24, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35544778

RESUMO

BACKGROUND: Many studies use similar methods to measure skin turgor, but there is no gold standard method that is being followed in clinics or hospitals. PURPOSE: The purpose of this systematic review was to determine if there is any consistent method to measure skin turgor in humans that is valid and reliable. METHODS: Topics of interest for turgor assessment included dehydration; skin integrity, including wounds and skin flaps; and fluid/electrolyte balance for adults 18 years and older. PubMed, ProQuest Medical, SPORTDiscus, PEDro, Web of Science Core Collection, and Cumulative Index of Nursing and Allied Health Literature complete databases were utilized. Levels of evidence were established with 2011 Oxford Centre for Evidence-Based Medicine scale. Methodological rigor was assessed with Quality Assessment of Diagnostic Accuracy Studies checklist. Two researchers graded rigor and level of evidence with a third researcher serving as a tie-breaker. RESULTS: Thirteen articles were included in the final analysis. Some researchers used skin turgor as a measure but did not give details regarding specifically how this measure was used. The pinch test was the most commonly used measure of skin turgor. There were 4 articles ranked as evidence level 2, 1 article as evidence level 3, and 8 articles as evidence level 4. Rigor scores ranged from 3 to 13/14. CONCLUSION: Skin turgor may not be the best assessment tool for some conditions or purposes in adults, such as dehydration, which could lead to a medical emergency.


Assuntos
Lista de Checagem , Desidratação , Adulto , Humanos
2.
Scand J Immunol ; 88(1): e12671, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29706017

RESUMO

Factor H is an important regulator of complement activation in plasma and on cell surfaces in both humans and mice. If FH function is compromised, inappropriate complement activation on self-surfaces can have disastrous effects as seen in the kidney diseases atypical haemolytic uremic syndrome (aHUS) and C3 glomerulopathy. As FH constructs have been proposed to be used in treatment for these diseases, we studied the distribution of exogenous FH fragments in mice. Full-length mFH, mFH1-5 and mFH18-20 fragments were radiolabelled, and their distribution was examined in WT, FH-/- and FH-/- C3-/- mice in vivo. Whole body scintigraphy revealed accumulation of radioactivity in the abdominal part of the mice, but also to the thyroid gland and urinary bladder. At organ level in WT mice, some full-length FH accumulated in internal organs, but most of it remained in the circulation. Both of the mFH fragments accumulated in the kidneys and were excreted in urine. For mFH1-5, urinary secretion is the likely cause for the accumulation. Concentration of mFH18-20 to kidneys was slower, and at tissue level, mFH18-20 was localized at the proximal tubuli in WT and FH-/- C3-/- mice. No C3-independent binding to glomeruli was detected. In conclusion, these results show that glomerular glycosaminoglycans and sialic acids alone do not collect FH in kidneys. Deposition of C3 fragments is also needed, which implies that in aHUS, the problem is in simultaneous recognition of C3 fragments and glycosaminoglycans or sialic acids by FH, not just the inability of FH to recognize glomerular endothelium as such.


Assuntos
Fator H do Complemento/metabolismo , Animais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fragmentos de Peptídeos/metabolismo , Distribuição Tecidual
3.
Stem Cells Transl Med ; 6(11): 1956-1962, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29067781

RESUMO

This article summarizes the recent activity of the International Stem Cell Banking Initiative (ISCBI) held at the California Institute for Regenerative Medicine (CIRM) in California (June 26, 2016) and the Korean National Institutes for Health in Korea (October 19-20, 2016). Through the workshops, ISCBI is endeavoring to support a new paradigm for human medicine using pluripotent stem cells (hPSC) for cell therapies. Priority considerations for ISCBI include ensuring the safety and efficacy of a final cell therapy product and quality assured source materials, such as stem cells and primary donor cells. To these ends, ISCBI aims to promote global harmonization on quality and safety control of stem cells for research and the development of starting materials for cell therapies, with regular workshops involving hPSC banking centers, biologists, and regulatory bodies. Here, we provide a brief overview of two such recent activities, with summaries of key issues raised. Stem Cells Translational Medicine 2017;6:1956-1962.


Assuntos
Bancos de Espécimes Biológicos/normas , Células-Tronco Embrionárias Humanas/citologia , Pesquisa com Células-Tronco , Bancos de Espécimes Biológicos/organização & administração , Congressos como Assunto , Humanos , Cooperação Internacional
4.
Methods Mol Biol ; 1590: 115-129, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28353265

RESUMO

Embryonic stem cells (ESCs) represent a mainstay for pluripotent stem cell research and development (R&D) and provide tangible opportunities for clinical translation including cell therapies and drug discovery. Moreover, in spite of the discovery of induced pluripotent stem cells (iPSCs), ESCs are an essential reference point, against which other pluripotent cells are compared. Hence, there is an ongoing need to derive and bank quality-controlled research-grade and clinical-grade ESC lines using established and standardized methods. Here, we provide a concise, step-by-step protocol for the derivation of ESCs from human embryos. While largely based on previously reported method for clinical-grade human ESC (hESC) line derivation, the protocol is suitable for routine application, although adaptable for clinical-compliance.


Assuntos
Técnicas de Cultura Embrionária/normas , Células-Tronco Embrionárias Humanas/citologia , Bancos de Espécimes Biológicos/normas , Linhagem Celular , Embrião de Mamíferos/citologia , Humanos
5.
Tissue Eng Part C Methods ; 22(11): 1009-1017, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27758135

RESUMO

Techniques to monitor the oxygen partial pressure (pO2) within implanted tissue-engineered grafts (TEGs) are critically necessary for TEG development, but current methods are invasive and inaccurate. In this study, we developed an accurate and noninvasive technique to monitor TEG pO2 utilizing proton (1H) or fluorine (19F) magnetic resonance spectroscopy (MRS) relaxometry. The value of the spin-lattice relaxation rate constant (R1) of some biocompatible compounds is sensitive to dissolved oxygen (and temperature), while insensitive to other external factors. Through this physical mechanism, MRS can measure the pO2 of implanted TEGs. We evaluated six potential MRS pO2 probes and measured their oxygen and temperature sensitivities and their intrinsic R1 values at 16.4 T. Acellular TEGs were constructed by emulsifying porcine plasma with perfluoro-15-crown-5-ether, injecting the emulsion into a macroencapsulation device, and cross-linking the plasma with a thrombin solution. A multiparametric calibration equation containing R1, pO2, and temperature was empirically generated from MRS data and validated with fiber optic (FO) probes in vitro. TEGs were then implanted in a dorsal subcutaneous pocket in a murine model and evaluated with MRS up to 29 days postimplantation. R1 measurements from the TEGs were converted to pO2 values using the established calibration equation and these in vivo pO2 measurements were simultaneously validated with FO probes. Additionally, MRS was used to detect increased pO2 within implanted TEGs that received supplemental oxygen delivery. Finally, based on a comparison of our MRS data with previously reported data, ultra-high-field (16.4 T) is shown to have an advantage for measuring hypoxia with 19F MRS. Results from this study show MRS relaxometry to be a precise, accurate, and noninvasive technique to monitor TEG pO2 in vitro and in vivo.


Assuntos
Órgãos Bioartificiais , Sobrevivência de Enxerto , Espectroscopia de Ressonância Magnética/métodos , Modelos Biológicos , Oxigênio/metabolismo , Animais , Engenharia Tecidual
6.
J Vis Exp ; (115)2016 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-27768027

RESUMO

In this demonstration, spheroids formed from the ß-TC6 insulinoma cell line were cultured as a model of manufacturing a mammalian islet cell product to demonstrate how regulating nutrient levels can improve cell yields. In previous studies, bioreactors facilitated increased culture volumes over static cultures, but no increase in cell yields were observed. Limitations in key nutrients such as glucose, which were consumed between batch feedings, can lead to limitations in cell expansion. Large fluctuations in glucose levels were observed, despite the increase in glucose concentrations in the media. The use of continuous feeding systems eliminated fluctuations in glucose levels, and improved cell growth rates when compared with batch fed static and SSB culture methods. Additional increases in growth rates were observed by adjusting the feed rate based on calculated nutrient consumption, which allowed the maintenance of physiological glucose over three weeks in culture. This method can also be adapted for other cell types.


Assuntos
Técnicas de Cultura de Células , Animais , Reatores Biológicos , Linhagem Celular , Meios de Cultura , Glucose , Ácido Láctico , Mamíferos
7.
Exp Biol Med (Maywood) ; 239(4): 484-8, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24595983

RESUMO

A major limitation of the use of cellular therapies is the loss of donor-derived cells because of immune incompatibility. While induced pluripotent stem (iPS) cells offer the potential for autologous transplant therapies, questions have been raised using a mouse model that specific antigens mediate the rejection of grafts after syngeneic transplants with iPS, but not embryonic stem (ES) cells. In this study, we examined whether the human homologs of these markers, HORMAD1, ZG16, and Cyp3A, are differentially expressed in human iPS versus ES cells, as well as undifferentiated and in vitro-differentiated cells. Both qRT-PCR and flow cytometric analyses demonstrated similar gene and protein expression profiles for iPS and ES cells regardless of differentiation state. Our data are consistent with a recent study in mice that showed no evidence of rejection of differentiated syngeneic iPS cells. Furthermore, our results suggest that expression of these gene products cannot predict differences in clinical outcomes between human iPS and ES-derived cells.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Citocromo P-450 CYP3A/metabolismo , Células-Tronco Embrionárias/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Lectinas/metabolismo , Diferenciação Celular , Células Cultivadas , Citometria de Fluxo , Perfilação da Expressão Gênica , Humanos , Reação em Cadeia da Polimerase em Tempo Real
8.
PLoS One ; 8(10): e76611, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24204645

RESUMO

Cellular therapies are emerging as a standard approach for the treatment of several diseases. However, realizing the promise of cellular therapies across the full range of treatable disorders will require large-scale, controlled, reproducible culture methods. Bioreactor systems offer the scale-up and monitoring needed, but standard stirred bioreactor cultures do not allow for the real-time regulation of key nutrients in the medium. In this study, ß-TC6 insulinoma cells were aggregated and cultured for 3 weeks as a model of manufacturing a mammalian cell product. Cell expansion rates and medium nutrient levels were compared in static, stirred suspension bioreactors (SSB), and continuously fed (CF) SSB. While SSB cultures facilitated increased culture volumes, no increase in cell yields were observed, partly due to limitations in key nutrients, which were consumed by the cultures between feedings, such as glucose. Even when glucose levels were increased to prevent depletion between feedings, dramatic fluctuations in glucose levels were observed. Continuous feeding eliminated fluctuations and improved cell expansion when compared with both static and SSB culture methods. Further improvements in growth rates were observed after adjusting the feed rate based on calculated nutrient depletion, which maintained physiological glucose levels for the duration of the expansion. Adjusting the feed rate in a continuous medium replacement system can maintain the consistent nutrient levels required for the large-scale application of many cell products. Continuously fed bioreactor systems combined with nutrient regulation can be used to improve the yield and reproducibility of mammalian cells for biological products and cellular therapies and will facilitate the translation of cell culture from the research lab to clinical applications.


Assuntos
Técnicas de Cultura Celular por Lotes , Reatores Biológicos , Meios de Cultura/química , Esferoides Celulares , Animais , Técnicas de Cultura Celular por Lotes/instrumentação , Técnicas de Cultura Celular por Lotes/métodos , Linhagem Celular , Proliferação de Células , Terapia Baseada em Transplante de Células e Tecidos/métodos , Glucose/química , Glucose/metabolismo , Humanos , Esferoides Celulares/metabolismo , Fatores de Tempo
9.
PLoS Pathog ; 9(4): e1003308, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23637600

RESUMO

To cause infections microbes need to evade host defense systems, one of these being the evolutionarily old and important arm of innate immunity, the alternative pathway of complement. It can attack all kinds of targets and is tightly controlled in plasma and on host cells by plasma complement regulator factor H (FH). FH binds simultaneously to host cell surface structures such as heparin or glycosaminoglycans via domain 20 and to the main complement opsonin C3b via domain 19. Many pathogenic microbes protect themselves from complement by recruiting host FH. We analyzed how and why different microbes bind FH via domains 19-20 (FH19-20). We used a selection of FH19-20 point mutants to reveal the binding sites of several microbial proteins and whole microbes (Haemophilus influenzae, Bordetella pertussis, Pseudomonas aeruginosa, Streptococcus pneumonia, Candida albicans, Borrelia burgdorferi, and Borrelia hermsii). We show that all studied microbes use the same binding region located on one side of domain 20. Binding of FH to the microbial proteins was inhibited with heparin showing that the common microbial binding site overlaps with the heparin site needed for efficient binding of FH to host cells. Surprisingly, the microbial proteins enhanced binding of FH19-20 to C3b and down-regulation of complement activation. We show that this is caused by formation of a tripartite complex between the microbial protein, FH, and C3b. In this study we reveal that seven microbes representing different phyla utilize a common binding site on the domain 20 of FH for complement evasion. Binding via this site not only mimics the glycosaminoglycans of the host cells, but also enhances function of FH on the microbial surfaces via the novel mechanism of tripartite complex formation. This is a unique example of convergent evolution resulting in enhanced immune evasion of important pathogens via utilization of a "superevasion site."


Assuntos
Bactérias/metabolismo , Candida albicans/metabolismo , Fator H do Complemento/metabolismo , Bactérias/genética , Bactérias/imunologia , Bactérias/patogenicidade , Sítios de Ligação , Bordetella pertussis/genética , Bordetella pertussis/imunologia , Bordetella pertussis/metabolismo , Bordetella pertussis/patogenicidade , Borrelia/genética , Borrelia/imunologia , Borrelia/metabolismo , Borrelia/patogenicidade , Candida albicans/genética , Candida albicans/imunologia , Candida albicans/patogenicidade , Membrana Celular/metabolismo , Ativação do Complemento , Fator H do Complemento/química , Haemophilus influenzae/genética , Haemophilus influenzae/imunologia , Haemophilus influenzae/metabolismo , Haemophilus influenzae/patogenicidade , Humanos , Ligação Proteica , Estrutura Terciária de Proteína , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/imunologia , Pseudomonas aeruginosa/metabolismo , Pseudomonas aeruginosa/patogenicidade , Staphylococcus aureus/genética , Staphylococcus aureus/imunologia , Staphylococcus aureus/metabolismo , Staphylococcus aureus/patogenicidade , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/imunologia , Streptococcus pneumoniae/metabolismo , Streptococcus pneumoniae/patogenicidade
10.
Regen Med ; 7(5): 685-95, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22954439

RESUMO

Numerous advances have been made in pancreatic ß-cell replacement therapies for diabetes mellitus. While these therapies provide a positive impact and possible cure for the individual recipient, access is limited by availability of donor tissues. The derivation of pluripotent stem cells using efficient differentiation technologies has resulted in the generation of insulin-producing cells with characteristics similar to islet ß-cells. Experimental transplantation studies have shown that these cells are capable of reducing hyperglycemia in short-term assays. Novel methodologies that facilitate the neogenesis of ß-cells from endogenous hepatic or pancreatic tissue sources are also being investigated as a ß-cell replacement strategy. Further research is necessary to protect these transplanted or regenerated cells from diabetic autoimmune pathology.


Assuntos
Técnicas de Cultura de Células/métodos , Diabetes Mellitus/terapia , Células Secretoras de Insulina/transplante , Medicina Regenerativa , Animais , Modelos Animais de Doenças , Humanos , Células-Tronco Pluripotentes/citologia
11.
Transpl Infect Dis ; 13(3): 266-72, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21176021

RESUMO

In this study, we evaluated the value of the Platelia(®) Candida mannan antigen (Ag) sandwich enzyme-linked immunosorbent assay test in the diagnosis of invasive candidiasis (IC) and the degree of oral colonization by Candida species in 102 allogeneic stem cell transplantation recipients who were not receiving fluconazole prophylaxis. Of the 2071 serum samples, 98 (4.7%) yielded positive and 78 (3.8%) borderline results with a cut-off value of 0.5 ng/mL. One patient had IC. In this patient, 6 out of 9 serum samples were positive, the first one 49 days before Candida albicans candidemia. False-positive results occurred in 92 (4.4%) samples and in 54 (52.9%) patients. Use of valacyclovir and acyclovir was associated with false-positive or borderline results. The median Ag concentration of the true-positive results was significantly higher than the concentration of the false-positive results (1.60 versus 0.62 ng/mL, P<0.001). With higher cut-off values of 0.75 and 1.0 ng/mL, false-positive Ag test results were seen in 17 and 7 patients, respectively. Of the 657 oral samples, a total of 92 (14%) samples in 39 (38.2%) patients turned out to be positive. C. albicans grew in 82 samples (89.1%), other Candida species in 9 (9.8%), and Aspergillus fumigatus in 1 sample (1.1%). In conclusion, despite the lack of fluconazole prophylaxis, the incidence of IC was low (1%). False-positive Ag test results were common with a test cut-off value of 0.5 ng/mL, and a single positive result does not seem to predict IC. Multiple positive results might predict IC, as 6 out of 9 samples were positive in the only patient with IC, the first one 7 weeks before positive blood cultures.


Assuntos
Antibioticoprofilaxia , Antígenos de Fungos/sangue , Antivirais/uso terapêutico , Candida/imunologia , Candidíase Invasiva/diagnóstico , Fluconazol/uso terapêutico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Mananas/sangue , Adolescente , Adulto , Candida/classificação , Candida albicans/imunologia , Candidemia/diagnóstico , Candidemia/imunologia , Candidemia/microbiologia , Candidemia/prevenção & controle , Candidíase Invasiva/imunologia , Candidíase Invasiva/microbiologia , Candidíase Invasiva/prevenção & controle , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Kit de Reagentes para Diagnóstico , Transplante Homólogo/efeitos adversos , Transplante Homólogo/imunologia , Adulto Jovem
12.
Ethn Dis ; 20(1 Suppl 1): S1-60-4, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20521387

RESUMO

INTRODUCTION: Endothelial dysfunction plays a critical role in the pathogenesis of cardiovascular diseases and cancer. Bone marrow-derived multipotent adult progenitor cells (MAPC) have the potential to differentiate, at the single cell level, toward the three embryonic germ layers and may be the progenitors of the other tissue-specific stem cells. However, molecular mechanisms of endothelial differentiation from MAPC have not been defined. The importance of epigenetic changes such as DNA methylation and histone acetylation in gene regulatory networks during embryonic stem cell (ESC) differentiation has been documented. We postulated that endothelial cell (EC) differentiation from MAPC could be enhanced by inhibiting DNA methylation and histone deacetylation, reversing the repression of genes that specify EC fate. METHODS: MAPCs were derived from rat bone marrow and differentiated into EC by vascular endothelial growth factor (VEGF) treatment in the presence or absence of the specific DNA methyltransferase (DNMT) inhibitor 5'-aza-2'-deoxycytidine (aza-dC) and the histone deacetylase (HDAC) inhibitor trichostatin A (TSA). Expression of the endothelial marker genes was assessed by real time quantitative PCR and angiogenic potential of the differentiated EC was assessed by analysis of vascular network formation on fibronectin. RESULTS: Both aza-dC and TSA induced at least a three-fold increase in the expression of the EC marker genes VE-cadherin, vWF, and Flk1. This increase was also observed in the presence of the EC differentiation inducer VEGF, suggesting that factors other than VEGF mediate the response to the epigenetic agents. Both DNMT and HDAC inhibition stimulated vascular network formation. CONCLUSION: Epigenetic therapy holds a potential in inducing self-repair, vascular tissue regeneration, controlling angiogenesis and endothelial dysfunction.


Assuntos
Diferenciação Celular/fisiologia , Metilação de DNA/fisiologia , Células Endoteliais/fisiologia , Inibidores de Histona Desacetilases/farmacologia , Células-Tronco Multipotentes/fisiologia , Animais , DNA (Citosina-5-)-Metiltransferases/antagonistas & inibidores , DNA (Citosina-5-)-Metiltransferases/fisiologia , Ratos , Ratos Sprague-Dawley , Fator A de Crescimento do Endotélio Vascular/fisiologia
13.
Bone Marrow Transplant ; 45(2): 333-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19617902

RESUMO

A study was performed to investigate the air quality of a haematopoietic SCT ward, colonization of the upper airways with Aspergillus spp. and the role of galactomannan (GM) ELISA testing in serum in the diagnosis of invasive aspergillosis (IA). In 102 allo-SCT recipients, two cases of IA (one proven and one probable) were seen. Of 2071 serum samples, 12 were positive, two in a patient with proven IA and 10 in patients without IA. Of the 2059 negative samples, 22 were taken from the patient with probable IA. Of the 245 environmental samples, 20 (8.2%) were positive for filamentous fungi. Aspergillus fumigatus was seen in 14 samples. A total of 657 oral and nasal swabs were taken. Seven nasal samples and one oral sample were positive for Aspergillus species (A. fumigatus 4, A. niger 4) in four patients, one of whom had probable IA. In summary, most environmental samples were negative, colonization of the oral and nasal cavities was rare and IA was diagnosed in only 2% of patients. The GM ELISA test remained negative in one of two patients with IA and does not seem useful in a population of patients with a low incidence of IA.


Assuntos
Aspergilose/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Mananas/análise , Microbiologia do Ar , Antígenos de Fungos/sangue , Aspergilose/microbiologia , Aspergillus fumigatus/imunologia , Ensaio de Imunoadsorção Enzimática , Galactose/análogos & derivados , Humanos , Mananas/imunologia , Boca/microbiologia , Nariz/microbiologia , Isolamento de Pacientes
14.
J Back Musculoskelet Rehabil ; 22(3): 157-64, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20023345

RESUMO

OBJECTIVES: Limited lower trunk rotation, which includes rotation of the lumbar spine, may hinder or even prevent functional activities. Currently, due to the lack of reliable, valid, and clinically useful tests, there is no standard objective measure of lower trunk rotation that can be easily performed in the clinic. The purpose of this study was to establish a standard protocol and to determine inter-rater and intra-rater reliability for a goniometric measurement developed to measure lower trunk rotation. METHODS: Lower trunk rotation was measured using a specific, goniometric method in 41 subjects. Each subject was measured 6 times by 2 different examiners for a total of 12 measurements. RESULTS: Pearson correlation coefficients indicate good intra-rater reliability ranging from 0.59 to 0.82 for right rotation (P< 0.001) and 0.76 to 0.82 for left rotation (P< 0.001), as well as good inter-rater reliability ranging from 0.62 to 0.83 with right rotation (P< 0.001) and 0.75 to 0.77 for left rotation (P< 0.001). CONCLUSION: This measure of trunk rotation may be useful for objectively documenting lower trunk rotation.


Assuntos
Artrometria Articular/estatística & dados numéricos , Artrometria Articular/normas , Vértebras Lombares/fisiologia , Amplitude de Movimento Articular/fisiologia , Adolescente , Adulto , Artrometria Articular/instrumentação , Feminino , Humanos , Masculino , Variações Dependentes do Observador , Maleabilidade/fisiologia , Reprodutibilidade dos Testes , Rotação , Adulto Jovem
15.
Euro Surveill ; 14(28)2009 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-19607781

RESUMO

We report the first foodborne outbreak caused by Cryptosporidium parvum in Finland. The outbreak occurred among personnel of the Public Works Department in Helsinki, who had eaten in the same canteen. 72 persons fell ill with diarrhoea, none was hospitalised. Four faecal samples obtained from 12 ill persons were positive for Cryptosporidium by an antigen identification assay and microscopy. The vehicle of infection could not be identified with certainty but a salad mixture was suspected.


Assuntos
Criptosporidiose/epidemiologia , Cryptosporidium parvum/isolamento & purificação , Surtos de Doenças , Parasitologia de Alimentos , Doenças Transmitidas por Alimentos/epidemiologia , Adulto , Idoso , Animais , Estudos de Casos e Controles , Fezes/parasitologia , Feminino , Finlândia/epidemiologia , Manipulação de Alimentos , Doenças Transmitidas por Alimentos/parasitologia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Inquéritos e Questionários , Verduras/parasitologia
16.
Differentiation ; 78(1): 18-23, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19398262

RESUMO

Human embryonic stem cell (hESC) lines are derived from the inner cell mass (ICM) of preimplantation human blastocysts obtained on days 5-6 following fertilization. Based on their derivation, they were once thought to be the equivalent of the ICM. Recently, however, studies in mice reported the derivation of mouse embryonic stem cell lines from the epiblast; these epiblast lines bear significant resemblance to human embryonic stem cell lines in terms of culture, differentiation potential and gene expression. In this study, we compared gene expression in human ICM cells isolated from the blastocyst and embryonic stem cells. We demonstrate that expression profiles of ICM clusters from single embryos and hESC populations were highly reproducible. Moreover, comparison of global gene expression between individual ICM clusters and human embryonic stem cells indicated that these two cell types are significantly different in regards to gene expression, with fewer than one half of all genes expressed in both cell types. Genes of the isolated human inner cell mass that are upregulated and downregulated are involved in numerous cellular pathways and processes; a subset of these genes may impart unique characteristics to hESCs such as proliferative and self-renewal properties.


Assuntos
Massa Celular Interna do Blastocisto/citologia , Embrião de Mamíferos/citologia , Células-Tronco Embrionárias/citologia , Perfilação da Expressão Gênica , Animais , Diferenciação Celular , Linhagem Celular , Separação Celular/métodos , Análise por Conglomerados , Técnicas de Cultura Embrionária/métodos , Embrião de Mamíferos/metabolismo , Células-Tronco Embrionárias/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Ligação Genética , Humanos , Camundongos , Modelos Biológicos
17.
Exp Biol Med (Maywood) ; 232(10): 1368-80, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17959850

RESUMO

To fully understand self-renewal and pluripotency and their regulation in human embryonic stem cells (hESCs), it is necessary to generate genetically modified cells and analyze the consequences of elevated and reduced expression of genes. Genes expressed in hESCs using plasmid vectors, however, are subject to silencing. Moreover, hESCs have a low plating efficiency when dissociated to single cells, making creation of subcloned lines inefficient. In addition to overexpression experiments, it is important to perform loss-of-function studies, which can be achieved rapidly using RNA interference (RNAi). We report stable long-term expression of enhanced green fluorescent protein (eGFP) in hESCs using a lentiviral vector, and establishment of an eGFP-expressing subline (RG6) using manual dissection. To demonstrate the efficacy of RNAi in hESCs, an RNAi expression vector was used to achieve reduced expression of eGFP in hESCs. To evaluate the role of OCT4 in the regulation of hESC self-renewal and differentiation, a vector expressing a hairpin RNA targeting endogenous expression of OCT4 was constructed. In a novel experiment in hESCs, the OCT4 cDNA sequence was cloned into an expression vector to allow for the transient upregulation of OCT4 in hESCs. The ability to manipulate levels of OCT4 above and below enodogenous levels allows the determination of OCT4 function in hESCs. Specifically, reduced expression of OCT4 in hESCs promoted upregulation of markers indicative of mesoderm and endoderm differentiation, and elevated levels of OCT4 in hESCs promoted upregulation of markers indicative of endoderm derivatives. Thus, both upregulation and downregulation of Oct4 in hESCs results in differentiation, but with patterns distinct from parallel experiments in mice.


Assuntos
Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/fisiologia , Fator 3 de Transcrição de Octâmero/genética , Sequência de Bases , Diferenciação Celular , Linhagem Celular , Eletroporação , Genes Reporter , Humanos , Imuno-Histoquímica , Dados de Sequência Molecular , Fator 3 de Transcrição de Octâmero/metabolismo , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção
18.
Curr Opin Chem Biol ; 11(4): 367-72, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17692558

RESUMO

Human embryonic stem cells, because of their unique combination of long-term self-renewal properties and pluripotency, are providing new avenues of investigation of stem cell biology and human development and show promise in providing a new source of human cells for transplantation therapies and pharmaceutical testing. Current methods of propagating these cells using combinations of mouse fibroblast feeder cultures and bovine serum components are inexpensive and, in general, useful. However, the systematic investigation of the regulation of self-renewal and the production of safer sources of cells for transplantation depends on the elimination of animal products and the use of defined culture conditions. Both goals are served by the development of serum-free culture methods for human embryonic stem cells.


Assuntos
Técnicas de Cultura de Células/métodos , Células-Tronco Embrionárias/citologia , Animais , Sobrevivência Celular , Meios de Cultura Livres de Soro , Humanos
19.
Bone Marrow Transplant ; 40(5): 457-60, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17589532

RESUMO

A 12-week environmental study was performed to ensure that the patient rooms of an SCT ward with high-efficiency particulate air (HEPA) filtration remained uncontaminated by moulds during close-by construction work. The sampling included measuring the ventilation channel pressure, particle count measurements, air sampling, settled dust analysis and fungal cultures from the oral and nasal cavities of the patients. No changes in the air pressure occurred. Median particle counts in patient rooms were 63-420 particles/l. The mean particle count of the outside air was 173,659 particles/l. Patient room air samples were negative for aspergilli in 32 of 33 cases. All samples of the outside air were positive for moulds. Aspergillus fumigatus was isolated at the beginning of excavation works at the construction area and in two of 33 dust samples from patient rooms. All 70 nasal samples were negative. Of 35 mouth samples, one sample was positive for A. niger in a patient with a previously diagnosed aspergillus infection. During a median follow-up of 214 days, no invasive aspergillus infections were diagnosed in the 55 patients treated during the construction period. In conclusion, the HEPA filters seemed to have performed well in preventing an aspergillosis outbreak.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Arquitetura de Instituições de Saúde , Fungos/isolamento & purificação , Unidades Hospitalares/normas , Transplante de Células-Tronco , Ventilação/métodos , Microbiologia do Ar , Aspergilose/prevenção & controle , Surtos de Doenças/prevenção & controle , Meio Ambiente , Exposição Ambiental , Humanos , Material Particulado/análise , Ventilação/normas
20.
Parasite Immunol ; 28(9): 421-8, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16916365

RESUMO

Intravascular Schistosoma mansoni worms seem to take up immunoglobulins from blood by surface Fc-receptors, but the process whereby bound immunoglobulins are processed by the parasite is poorly understood. We here present morphological data suggesting that two distinct main processes are involved: Host immunoglobulins were seen at two distinct locations in the parasite: in the frontal part of the enteric tube, the oesophagus, and as a fine granular staining at the surface and in the subtegumental region. The latter staining pattern corresponds to host immunoglobulin localization in discrete organelle-like aggregates tentatively identified as 'discoid or elongate bodies' at the ultrastructural level using immunogold staining. Immunoglobulin uptake by intravascular worms was also demonstrated in vivo after passive administration of 125I-labelled rabbit and mouse immunoglobulins. Radiolabelled immunoglobulins were taken up by the worms and shown to localize as fine strands running perpendicular to the parasite surface. Our results suggest that intravascular schistosomes take up host immunoglobulins both as part of their enteric digestion and by a surface Fc-receptor-mediated mechanism, involving transport and processing within organelles, 'elongate bodies'. Immunoglobulins taken up by intravascular schistosomes form a distinct organelle-like granules, which seem to be processed within the excretory system of the parasite.


Assuntos
Imunoglobulinas/metabolismo , Schistosoma mansoni/metabolismo , Animais , Autorradiografia/métodos , Imunoglobulinas/sangue , Imunoglobulinas/imunologia , Imuno-Histoquímica/métodos , Camundongos , Camundongos Endogâmicos C3H , Microscopia de Fluorescência/métodos , Microscopia de Polarização/métodos , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Esquistossomose mansoni/metabolismo , Esquistossomose mansoni/parasitologia
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