Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Can J Diabetes ; 47(1): 43-50.e3, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36180335

RESUMO

OBJECTIVES: Pregnancy may be complicated by gestational diabetes mellitus (GDM) and/or microvascular complications like albuminuria, retinopathy and pre-eclampsia. In this study we aimed to identify whether mechanistic pathways associated with microvascular complications are active in pregnant women with GDM or microvascular disease. METHODS: Urinary albumin excretion and biomarkers of inflammation, lipoprotein metabolism and tubular injury were quantified in 355 pregnant women with and without GDM. Participants underwent fundus photography graded for retinopathy. Adjusted associations between individual biomarkers and each outcome variable of interest, including GDM status, albuminuria and retinopathy, were performed using logistic regression. RESULTS: After adjusting for age, systolic blood pressure, body mass index and ethnicity, significant associations between GDM status and apolipoprotein A1, interleukin (IL)-6, IL-8, soluble tumour necrosis factor receptor-I and -II (sTNFR-I and -II), vascular endothelial growth factor and von Willebrand factor were observed. Increased high-sensitivity C-reactive protein (hsCRP) and sTNFR-II were associated with higher levels of albuminuria. hsCRP and previous GDM were associated with retinopathy. CONCLUSION: Mechanistic pathways associated with microvascular complications appear to be active in pregnant women with GDM or microvascular disease.


Assuntos
Diabetes Gestacional , Doenças Retinianas , Gravidez , Humanos , Feminino , Fatores de Risco , Proteína C-Reativa , Albuminúria , Metabolismo dos Lipídeos , Fator A de Crescimento do Endotélio Vascular , Biomarcadores , Inflamação/complicações , Doenças Retinianas/complicações
2.
Diabetes Res Clin Pract ; 180: 109068, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34563584

RESUMO

AIMS: The risk of microvascular disease has been thought to commence with the onset of overt diabetes. Women with gestational diabetes have only had a short-term exposure to frank hyperglycemia, but, due to underlying ß-cell dysfunction, they may also have had long-term exposure to mild degrees of hyperglycemia. The aim of the study was to determine whether women with gestational diabetes are at increased risk for microalbuminuria and retinopathy compared to women with normal glucose tolerance in pregnancy. METHODS: We recruited women aged ≥ 25 years with singleton pregnancies at 32 to 40 weeks' gestational age, with and without gestational diabetes. Women with hypertension, preeclampsia, or pre-gestational diabetes were excluded. RESULTS: Of 372 women included in the study, 195 had gestational diabetes. The prevalence of microalbuminuria was 15% among those with gestational diabetes versus 6% in those with normal glucose tolerance (adjusted odds ratio 2.4, 95% confidence interval 1.1 to 5.2, p = 0.006). Diastolic blood pressure and HbA1c were associated with microalbuminuria. The prevalence of retinopathy did not differ between groups (10% versus 11%). CONCLUSIONS: Women with gestational diabetes have an increased risk of microalbuminuria in the third trimester, despite having been exposed to only a brief period of overt hyperglycemia.


Assuntos
Diabetes Gestacional , Hiperglicemia , Pré-Eclâmpsia , Diabetes Gestacional/epidemiologia , Feminino , Humanos , Gravidez , Terceiro Trimestre da Gravidez , Fatores de Risco
3.
Stem Cell Res Ther ; 9(1): 193, 2018 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-30005703

RESUMO

BACKGROUND: Compromised wound healing has become a global public health challenge which presents a significant psychological, financial, and emotional burden on patients and physicians. We recently reported that acellular gelatinous Wharton's jelly of the human umbilical cord enhances skin wound healing in vitro and in vivo in a murine model; however, the key player in the jelly which enhances wound healing is still unknown. METHODS: We performed mass spectrometry on acellular gelatinous Wharton's jelly to elucidate the chemical structures of the molecules. Using an ultracentrifugation protocol, we isolated exosomes and treated fibroblasts with these exosomes to assess their proliferation and migration. Mice were subjected to a full-thickness skin biopsy experiment and treated with either control vehicle or vehicle containing exosomes. Isolated exosomes were subjected to further mass spectrometry analysis to determine their cargo. RESULTS: Subjecting the acellular gelatinous Wharton's jelly to proteomics approaches, we detected a large amount of proteins that are characteristic of exosomes. Here, we show that the exosomes isolated from the acellular gelatinous Wharton's jelly enhance cell viability and cell migration in vitro and enhance skin wound healing in the punch biopsy wound model in mice. Mass spectrometry analysis revealed that exosomes of Wharton's jelly umbilical cord contain a large amount of alpha-2-macroglobulin, a protein which mimics the effect of acellular gelatinous Wharton's jelly exosomes on wound healing. CONCLUSIONS: Exosomes are being enriched in the native niche of the umbilical cord and can enhance wound healing in vivo through their cargo. Exosomes from the acellular gelatinous Wharton's jelly and the cargo protein alpha-2-macroglobulin have tremendous potential as a noncellular, off-the-shelf therapeutic modality for wound healing.


Assuntos
Células-Tronco Mesenquimais/metabolismo , Cordão Umbilical/metabolismo , Geleia de Wharton/metabolismo , Animais , Movimento Celular , Exossomos , Humanos , Masculino , Camundongos , Cicatrização
4.
Front Physiol ; 8: 200, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28421003

RESUMO

Impaired wound healing is a severe clinical challenge and research into finding effective wound healing strategies is underway as there is no ideal treatment. Gelatinous material from the umbilical cord called Wharton's jelly is a valuable source of mesenchymal stem cells which have been shown to aid wound healing. While the cellular component of Wharton's jelly has been the subject of extensive research during the last few years, little is known about the de-cellularized jelly material of the umbilical cord. This is important as they are native niche of stem cells. We have isolated Wharton's jelly from umbilical cords and then fractionated acellular gelatinous Wharton's jelly (AGWJ). Here, we show for the first time that AGWJ enhances wound healing in vitro as well as in vivo for wounds in a murine model. In vivo staining of the wounds revealed a smaller wound length in the AGWJ treated wounds in comparison to control treatment by enhancing cell migration and differentiation. AGWJ significantly enhanced fibroblast cell migration in vitro. Aside from cell migration, AGWJ changed the cell morphology of fibroblasts to a more elongated phenotype, characteristic of myofibroblasts, confirmed by upregulation of alpha smooth muscle actin using immunoblotting. AGWJ treatment of wounds led to accelerated differentiation of cells into myofibroblasts, shortening the proliferation phase of wound healing. This data provides support for a novel wound healing remedy using AGWJ. AGWJ being native biological, cost effective and abundantly available globally, makes it a highly promising treatment option for wound dressing and skin regeneration.

5.
Diabetes Care ; 39(12): 2204-2210, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27634392

RESUMO

OBJECTIVE: To assess the frequency of adverse outcomes for women who are diagnosed with gestational diabetes mellitus (GDM) by the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria using data from the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study. RESEARCH DESIGN AND METHODS: This is a secondary analysis from the North American HAPO study centers. Glucose measurements from a 75-g oral glucose tolerance test were used to group participants into three nonoverlapping categories: GDM based on Carpenter-Coustan (CC) criteria (also GDM based on IADPSG criteria), GDM diagnosed based on IADPSG criteria but not CC criteria, and no GDM. Newborn outcomes included birth weight, cord C-peptide, and newborn percentage fat above the 90th percentile; maternal outcomes included primary cesarean delivery and preeclampsia. Outcome frequencies were compared using multiple logistic regression, adjusting for predefined covariates. RESULTS: Among 25,505 HAPO study participants, 6,159 blinded participants from North American centers were included. Of these, 81% had normal glucose testing, 4.2% had GDM based on CC criteria, and 14.3% had GDM based on IADPSG criteria but not CC criteria. Compared with women with no GDM, those diagnosed with GDM based on IADPSG criteria had adjusted odds ratios (95% CIs) for birth weight, cord C-peptide, and newborn percentage fat above the 90th percentile, as well as primary cesarean delivery and preeclampsia, of 1.87 (1.50-2.34), 2.00 (1.54-2.58), 1.73 (1.35-2.23), 1.31 (1.07-1.60), and 1.73 (1.32-2.27), respectively. CONCLUSIONS: Women diagnosed with GDM based on IADPSG criteria had higher adverse outcome frequencies compared with women with no GDM. These data underscore the need for research to assess the effect of treatment to improve outcomes in such women.


Assuntos
Diabetes Gestacional/diagnóstico , Diabetes Gestacional/epidemiologia , Hiperglicemia/epidemiologia , Resultado da Gravidez/epidemiologia , Adulto , Feminino , Teste de Tolerância a Glucose , Humanos , Hiperglicemia/diagnóstico , Recém-Nascido , Doenças do Recém-Nascido/diagnóstico , Doenças do Recém-Nascido/epidemiologia , Morbidade , Pré-Eclâmpsia/diagnóstico , Pré-Eclâmpsia/epidemiologia , Gravidez , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/epidemiologia , Prognóstico , História Reprodutiva , Estudos Retrospectivos
6.
Stem Cell Res Ther ; 5(1): 28, 2014 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-24564987

RESUMO

INTRODUCTION: The prevalence of nonhealing wounds is predicted to increase due to the growing aging population. Despite the use of novel skin substitutes and wound dressings, poorly vascularized wound niches impair wound repair. Mesenchymal stem cells (MSCs) have been reported to provide paracrine signals to promote wound healing, but the effect of human Wharton's jelly-derived MSCs (WJ-MSCs) has not yet been described in human normal skin. METHODS: Human WJ-MSCs and normal skin fibroblasts were isolated from donated umbilical cords and normal adult human skin. Fibroblasts were treated with WJ-MSC-conditioned medium (WJ-MSC-CM) or nonconditioned medium. RESULTS: Expression of genes involved in re-epithelialization (transforming growth factor-ß2), neovascularization (hypoxia-inducible factor-1α) and fibroproliferation (plasminogen activator inhibitor-1) was upregulated in WJ-MSC-CM-treated fibroblasts (P≤0.05). WJ-MSC-CM enhanced normal skin fibroblast proliferation (P≤0.001) and migration (P≤0.05), and promoted wound healing in an excisional full-thickness skin murine model. CONCLUSIONS: Under our experimental conditions, WJ-MSCs enhanced skin wound healing in an in vivo mouse model.


Assuntos
Células-Tronco Mesenquimais/citologia , Comunicação Parácrina , Reepitelização , Pele/citologia , Animais , Diferenciação Celular , Movimento Celular , Proliferação de Células , Células Cultivadas , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibroblastos/fisiologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Inibidor 1 de Ativador de Plasminogênio/genética , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Pele/lesões , Fator de Crescimento Transformador beta2/genética , Fator de Crescimento Transformador beta2/metabolismo , Geleia de Wharton/citologia
7.
Stem Cells Transl Med ; 3(3): 299-307, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24436441

RESUMO

Keloid scars are abnormal benign fibroproliferative tumors with high recurrence rates and no current efficacious treatment. Accumulating evidence suggests that human umbilical cord Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) have antifibrotic properties. Paracrine signaling is considered one of the main underlying mechanisms behind the therapeutic effects of mesenchymal stem cells. However, the paracrine signaling effects of WJ-MSCs on keloids have not yet been reported. The aim of this study is to investigate paracrine signaling effects of human WJ-MSCs on keloid fibroblasts in vitro. Human umbilical cords and keloid skin samples were obtained, and WJ-MSCs and keloid fibroblasts were isolated and cultured. One-way and two-way paracrine culture systems between both cell types were investigated. Plasminogen activator inhibitor-I and transforming growth factor-ß2 (TGF-ß2) transcripts were upregulated in keloid fibroblasts cultured with WJ-MSC-conditioned medium (WJ-MSC-CM) and cocultured with inserts, while showing lower TGF-ß3 gene expression. Interleukin (IL)-6, IL-8, TGF-ß1, and TGF-ß2 protein expression was also enhanced. The WJ-MSC-CM-treated keloid fibroblasts showed higher proliferation rates than their control keloid fibroblasts with no significant change in apoptosis rate or migration ability. In our culture conditions, the indirect application of WJ-MSCs on keloid fibroblasts may enhance their profibrotic phenotype.


Assuntos
Meios de Cultivo Condicionados/farmacologia , Sangue Fetal/metabolismo , Fibroblastos/efeitos dos fármacos , Queloide/metabolismo , Células-Tronco Mesenquimais/metabolismo , Comunicação Parácrina/efeitos dos fármacos , Geleia de Wharton/metabolismo , Proliferação de Células/efeitos dos fármacos , Técnicas de Cocultura , Cultura em Câmaras de Difusão , Sangue Fetal/citologia , Fibroblastos/metabolismo , Fibroblastos/patologia , Regulação da Expressão Gênica , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-8/genética , Interleucina-8/metabolismo , Queloide/genética , Queloide/patologia , Células-Tronco Mesenquimais/citologia , Inibidor 1 de Ativador de Plasminogênio/genética , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Cultura Primária de Células , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta2/genética , Fator de Crescimento Transformador beta2/metabolismo , Fator de Crescimento Transformador beta3/genética , Fator de Crescimento Transformador beta3/metabolismo , Geleia de Wharton/citologia
8.
Blood ; 123(8): 1167-77, 2014 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-24363404

RESUMO

All blood cell lineages start from hematopoietic stem cells (HSCs), which were recently shown to represent a heterogeneous group of cells. In mice, Notch signaling promotes the maintenance of "stemness" as well as the expansion of self-renewing HSCs in vitro. Additionally, human CD34(+) cells were shown to expand in vitro in response to Notch signals. However, it is unclear whether Notch directly affects all HSCs, and whether this role is relevant in vivo. Here, we developed culture conditions that support the maintenance of CD34(+)CD133(+)CD90(low)CD38(-)CD7(-)CD10(-)CD45RA(-) (CD90(low)) cells, phenotypically defined HSCs, as well as 2 early progenitor cells (CD34(+)CD38(-)CD7(-)CD10(-)CD45RA(int) [RA(int)] and CD34(+)CD38(-)CD7(-)CD10(-)CD45RA(hi) [RA(hi)]) that were functionally equivalent to multipotent progenitor-2 and lymphoid-primed multipotent progenitor, respectively, found in cord blood. Using a genetic approach, we show that Notch signals were required for HSC preservation, with cultured HSCs being equal to ex vivo HSC cells in their ability to reconstitute immunodeficient mice; however, dnMaml-transduced HSCs were not maintained in vitro. Interestingly, Notch signaling did not appear to be required for the self-renewal of human HSCs in vivo. Our findings support the notion that Notch signals maintain human HSCs in vitro that have hematopoietic-reconstituting ability in vivo and delay the appearance of 2 newly described early progenitor cells.


Assuntos
Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Multipotentes/citologia , Células-Tronco Multipotentes/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais/fisiologia , Animais , Diferenciação Celular/fisiologia , Células Cultivadas , Técnicas de Cocultura , Feminino , Sangue Fetal/citologia , Humanos , Imunofenotipagem , Antígenos Comuns de Leucócito/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos SCID , Receptores Notch/genética
9.
Blood ; 122(26): 4210-9, 2013 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-24215033

RESUMO

Hematopoietic stem cell transplantation (HSCT) is followed by a period of immune deficiency due to a paucity in T-cell reconstitution. Underlying causes are a severely dysfunctional thymus and an impaired production of thymus-seeding progenitors in the host. Here, we addressed whether in vitro-derived human progenitor T (proT)-cells could not only represent a source of thymus-seeding progenitors, but also able to influence the recovery of the thymic microenvironment. We examined whether co-transplantation of in vitro-derived human proT-cells with hematopoietic stem cells (HSCs) was able to facilitate HSC-derived T-lymphopoiesis posttransplant. A competitive transfer approach was used to define the optimal proT subset capable of reconstituting immunodeficient mice. Although the 2 subsets tested (proT1, CD34(+)CD7(+)CD5(-); proT2, CD34(+)CD7(+)CD5(+)) showed thymus engrafting function, proT2-cells exhibited superior engrafting capacity. Based on this, when proT2-cells were coinjected with HSCs, a significantly improved and accelerated HSC-derived T-lymphopoiesis was observed. Furthermore, we uncovered a potential mechanism by which receptor activator of nuclear factor κb (RANK) ligand-expressing proT2-cells induce changes in both the function and architecture of the thymus microenvironment, which favors the recruitment of bone marrow-derived lymphoid progenitors. Our findings provide further support for the use of Notch-expanded progenitors in cell-based therapies to aid in the recovery of T-cells in patients undergoing HSCT.


Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Células-Tronco Hematopoéticas/citologia , Síndromes de Imunodeficiência/terapia , Linfopoese/imunologia , Linfócitos T/citologia , Timo/citologia , Animais , Diferenciação Celular/imunologia , Células Cultivadas , Técnicas de Cocultura , Modelos Animais de Doenças , Humanos , Síndromes de Imunodeficiência/imunologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Regeneração/imunologia , Células Estromais/citologia , Células Estromais/imunologia , Linfócitos T/imunologia , Timo/imunologia
10.
BMC Immunol ; 12: 22, 2011 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-21429219

RESUMO

BACKGROUND: T cell development occurs within the highly specialized thymus. Cytotoxic CD8 T cells are critical in adaptive immunity by targeting virally infected or tumor cells. In this study, we addressed whether functional CD8 T cells can be generated fully in vitro using human umbilical cord blood (UCB) hematopoietic stem cells (HSCs) in coculture with OP9-DL1 cells. RESULTS: HSC/OP9-DL1 cocultures supported the differentiation of CD8 T cells, which were TCR/CD3(hi) CD27(hi) CD1a(neg) and thus phenotypically resembled mature functional CD8 single positive thymocytes. These in vitro-generated T cells also appeared to be conventional CD8 cells, as they expressed high levels of Eomes and low levels of Plzf, albeit not identical to ex vivo UCB CD8 T cells. Consistent with the phenotypic and molecular characterization, upon TCR-stimulation, in vitro-generated CD8 T cells proliferated, expressed activation markers (MHC-II, CD25, CD38), secreted IFN-γ and expressed Granzyme B, a cytotoxic T-cell effector molecule. CONCLUSION: Taken together, the ability to direct human hematopoietic stem cell or T-progenitor cells towards a mature functional phenotype raises the possibility of establishing cell-based treatments for T-immunodeficiencies by rapidly restoring CD8 effector function, thereby mitigating the risks associated with opportunistic infections.


Assuntos
Linfócitos T CD8-Positivos/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Ativação Linfocitária , Linfopoese , Proteínas com Domínio T/metabolismo , Antígenos CD/biossíntese , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular , Técnicas de Cocultura , Sangue Fetal/citologia , Regulação da Expressão Gênica no Desenvolvimento/imunologia , Granzimas/genética , Granzimas/metabolismo , Células-Tronco Hematopoéticas/citologia , Humanos , Imunofenotipagem , Interferon gama/genética , Interferon gama/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/imunologia , Proteína com Dedos de Zinco da Leucemia Promielocítica , Receptores de Antígenos de Linfócitos T/imunologia , Células Estromais/citologia , Proteínas com Domínio T/genética , Proteínas com Domínio T/imunologia
11.
AJP Rep ; 1(1): 47-52, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23705085

RESUMO

We evaluated the role of uterine compression sutures as a conservative treatment for postpartum hemorrhage (PPH) after failed medical treatment. We retrospectively reviewed the charts of all patients who delivered between 2003 and 2009 at a single tertiary care center and who underwent uterine compression sutures for PPH. Twelve women had uterine compression sutures for PPH. The mean age of the patients was 36.3 ± 5.2 years. The mean gestational age at delivery was 37.7 ± 2.0 weeks, and the average estimated blood loss was 2.1 ± 1.1 L. The mean procedure time to perform the uterine compression sutures was 9.3 ± 2.8 minutes. The success rate of compression sutures was 92% with only one failure resulting in a hysterectomy. Uterine compression sutures are an effective method for the treatment of PPH, thus avoiding hysterectomy and preserving potential fertility.

12.
J Obstet Gynaecol Can ; 32(3): 209-16, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20500964

RESUMO

OBJECTIVE: Postpartum depression (PPD) is a common and recurring illness. Most women who experience PPD do not seek professional help; for those who do, the available treatment options are not supported by extensive research evidence. Several lines of research have linked omega-3 fatty acids (omega-3) supplementation with a reduced risk of PPD. Although it has been suggested that women in the perinatal period consume sufficient omega-3 to potentially prevent PPD, there is a lack of definitive research evidence. This pilot study surveyed pregnant women's current use of omega-3, multivitamin, and other supplements, as well as their attitudes toward omega-3 research during pregnancy, to assess the feasibility of pregnant women's participation in a large randomized controlled trial evaluating omega-3 supplementation. METHODS: Women attending prenatal clinics over a three-week period were invited to participate in a survey. The survey contained an information letter that was followed by a brief questionnaire assessing the use of nutritional supplements and opinions regarding the likelihood of participating in a clinical trial during pregnancy. RESULTS: Of the 176 women who completed the survey, six women were in the first trimester of pregnancy, 82 were in the second trimester, and 87 were in the third trimester. One hundred fifty-nine respondents (90.3%) reported taking a multivitamin supplement but none were taking a supplement that contained omega-3; only 20 (11.4%) were taking omega-3. Seventy-eight women (44.4%) responded that they would participate in a clinical study evaluating the effects of fish oil on their health. CONCLUSION: The results of our study indicate that many pregnant women take prenatal multivitamins and nutritional supplements, that there are currently few pregnant women attending clinics at our hospitals who are supplementing with omega-3, and that pregnant women would be willing to participate in a clinical trial evaluating the effects of omega-3.


Assuntos
Atitude Frente a Saúde , Suplementos Nutricionais/estatística & dados numéricos , Ácidos Graxos Ômega-3/uso terapêutico , Comportamentos Relacionados com a Saúde , Cuidado Pré-Natal , Instituições de Assistência Ambulatorial , Feminino , Humanos , Ontário , Projetos Piloto , Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Inquéritos e Questionários , Vitaminas/uso terapêutico
13.
Blood ; 114(5): 972-82, 2009 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-19491395

RESUMO

T-cell development follows a defined set of stage-specific differentiation steps. However, molecular and cellular events occurring at early stages of human T-cell development remain to be fully elucidated. To address this, human umbilical cord blood (UCB) hematopoietic stem cells (HSCs) were induced to differentiate to the T lineage in OP9-DL1 cocultures. A developmental program involving a sequential and temporally discrete expression of key differentiation markers was revealed. Quantitative clonal analyses demonstrated that CD34(+)CD38(-) and CD34(+)CD38(lo) subsets of UCB contain a similarly high T-lineage progenitor frequency, whereas the frequency in CD34(+)CD38(+/hi) cells was 5-fold lower. Delta-like/Notch-induced signals increased the T-cell progenitor frequency of CD34(+)CD38(-/lo) cells differentiated on OP9-DL1, and 2 distinct progenitor subsets, CD34(+)CD45RA(+)CD7(++)CD5(-)CD1a(-) (proT1) and CD34(+)CD45RA(+)CD7(++)CD5(+)CD1a(-) (proT2), were identified and their thymus engrafting capacity was examined, with proT2 cells showing a 3-fold enhanced reconstituting capacity compared with the proT1 subset. Furthermore, in vitro-generated CD34(+)CD7(++) progenitors effectively engrafted the thymus of immunodeficient mice, which was enhanced by the addition of an IL-7/IL-7 antibody complex. Taken together, the identification of T-progenitor subsets readily generated in vitro may offer important avenues to improve cellular-based immune-reconstitution approaches.


Assuntos
Células-Tronco Hematopoéticas/citologia , Subpopulações de Linfócitos T/citologia , Animais , Complexo Antígeno-Anticorpo/farmacologia , Antígenos CD/análise , Linhagem da Célula , Células Cultivadas/citologia , Células Cultivadas/transplante , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Sangue Fetal/citologia , Humanos , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/imunologia , Síndromes de Imunodeficiência/cirurgia , Recém-Nascido , Subunidade gama Comum de Receptores de Interleucina/deficiência , Subunidade gama Comum de Receptores de Interleucina/genética , Interleucina-7/imunologia , Interleucina-7/farmacologia , Linfopoese , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Técnicas de Cultura de Órgãos , Organismos Livres de Patógenos Específicos , Subpopulações de Linfócitos T/química , Subpopulações de Linfócitos T/transplante , Timo/citologia , Timo/embriologia , Transplante Heterólogo
14.
Obstet Gynecol ; 112(2 Pt 2): 478-80, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18669771

RESUMO

BACKGROUND: Wandering spleen is a rare entity characterized by the incomplete fixation of the gastrosplenic ligaments. Several imaging modalities have been used to diagnose this condition, including Doppler ultrasonography, computed tomography, nuclear scintigraphy, and magnetic resonance imaging. CASE: We report a case of an asymptomatic woman presenting to a family planning center. An adnexal mass palpated on pelvic examination was diagnosed subsequently as a wandering spleen. CONCLUSION: This case illustrates that ultrasonography and nuclear medicine are useful to make a definitive diagnosis of wandering spleen.


Assuntos
Baço Flutuante/diagnóstico por imagem , Adulto , Feminino , Humanos , Pelve/diagnóstico por imagem , Cintilografia , Coloide de Enxofre Marcado com Tecnécio Tc 99m , Ultrassonografia
15.
J Clin Ultrasound ; 34(9): 446-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16960882

RESUMO

Pregnancy within a noncommunicating rudimentary horn has a 70% chance of rupturing, with a maternal mortality of 0.5%. It is most commonly managed with operative removal of the horn. We report a pregnancy within a noncommunicating horn and highlight the advantage of early diagnosis via sonography. First trimester prenatal screening via sonographic examination allows early diagnosis of müllerian duct abnormalities and ectopic pregnancy. This information expedites management of such pregnancies, thus decreasing maternal morbidity and increasing the chance of future fertility.


Assuntos
Gravidez Ectópica/diagnóstico por imagem , Útero/anormalidades , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Gravidez , Primeiro Trimestre da Gravidez , Gravidez Ectópica/cirurgia , Ultrassonografia , Útero/diagnóstico por imagem , Útero/cirurgia
16.
Blood ; 105(4): 1431-9, 2005 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-15494433

RESUMO

The Notch signaling pathway plays a key role at several stages of T-lymphocyte differentiation. However, it remained unclear whether signals induced by the Notch ligand Delta-like 1 could support full T-cell differentiation from a defined source of human hematopoietic stem cells (HSCs) in vitro. Here, we show that human cord blood-derived HSCs cultured on Delta-like 1-expressing OP9 stromal cells undergo efficient T-cell lineage commitment and sustained T-cell differentiation. A normal stage-specific program of T-cell development was observed, including the generation of CD4 and CD8 alpha beta-T-cell receptor (TCR)-bearing cells. Induction of T-cell differentiation was dependent on the expression of Delta-like 1 by the OP9 cells. Stimulation of the in vitro-differentiated T cells by TCR engagement induced the expression of T-cell activation markers and costimulatory receptors. These results establish an efficient in vitro coculture system for the generation of T cells from human HSCs, providing a new avenue for the study of early T-cell differentiation and function.


Assuntos
Diferenciação Celular/fisiologia , Sangue Fetal/citologia , Sangue Fetal/fisiologia , Glicoproteínas/fisiologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/fisiologia , Proteínas de Membrana/fisiologia , Linfócitos T/citologia , Linfócitos T/fisiologia , Animais , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/fisiologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/fisiologia , Linhagem Celular , Linhagem da Célula/imunologia , Técnicas de Cocultura , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Ativação Linfocitária/imunologia , Camundongos , Complexo Receptor-CD3 de Antígeno de Linfócitos T/fisiologia , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Linfócitos T/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...