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1.
Climacteric ; 26(6): 613-618, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37665643

RESUMO

OBJECTIVE: This study aimed at evaluating the prevalence and management of postmenopausal symptoms among Rwandan women. METHODS: A descriptive cross-sectional study was conducted at the four largest Rwandan referral hospitals from August 2017 to March 2018 among postmenopausal women. Data on postmenopausal symptoms were collected using the Modified Blatt-Kupperman Menopausal Index and score ranges of 0-6, 7-15, 16-30 and >30 were used to rate the degree of severity as none, mild, moderate, and severe, respectively. RESULTS: Six hundred participants were recruited. The mean age at natural menopause was 51.7 ± 5.6 years. Common symptoms were hot flushes (82%), sexual complaints (66%) and headache (61%). The mean Blatt-Kupperman index score was 21.2 (1-58). Participants' symptoms were classified as severe (35.8%), moderate (49.0%), mild (11.3%) and none (3.8%). Among 41.2% who had sought medical care, 1.7% were given hormonal replacement and 36% were given only pain medications. Age >50 years and lack of a male partner were significantly associated with higher scores. CONCLUSIONS: Postmenopausal symptoms remain a burden among Rwandan women and little consideration is given for optimal management. There is a need for health managers to consider this inevitable phase of life on the health policy agenda for equitable healthy aging.


Assuntos
Menopausa , Pós-Menopausa , Feminino , Masculino , Humanos , Pessoa de Meia-Idade , Ruanda/epidemiologia , Prevalência , Estudos Transversais , Fogachos/epidemiologia , Fogachos/terapia
2.
Osteoporos Int ; 27(1): 309-18, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26446770

RESUMO

UNLABELLED: The cathepsin K inhibitor, ONO-5334, improves bone mineral density in postmenopausal women with osteoporosis. The effects of morning versus evening administration of ONO-5334 were investigated by measuring bone turnover marker levels in healthy postmenopausal women. Morning administration of ONO-5334 showed a more consistent suppressive effect on bone resorption than evening administration. INTRODUCTION: Bone turnover is thought to be subject to circadian variation, and the efficacy of osteoporosis treatments may be optimized by regulating the time of dosing. This study assessed whether evening administration of the cathepsin K inhibitor, ONO-5334, had a differential effect on the bone turnover marker, C-terminal telopeptide of type I collagen (CTX-I), compared with morning administration. METHODS: This was a single-center, single blind crossover study. Fourteen healthy postmenopausal women were assigned to receive ONO-5334 150 mg once daily for 5 days in each period; they were randomized to receive either evening doses in the first period and morning doses in the second or vice versa. Serum and urinary levels of CTX-I were measured throughout the study. RESULTS: Both regimens showed similar patterns of reduction in serum and urinary CTX-I; however, CTX-I suppression was more consistently >60% over 24 h following morning administration. Morning administration led to 6% greater suppression of 24-h serum CTX-I area under the effect curve (AUE; 69 vs 63%; P < .05) and 7% greater suppression of urinary CTX-I/creatinine AUE (93 vs 86%; P < .01) than evening administration. Higher plasma ONO-5334 concentrations were observed between 12 and 24 h postdose following morning administration, with mean trough concentrations for the morning and evening regimens at 9.4 and 4.0 ng/mL, respectively. There were no safety findings of concern. CONCLUSION: Morning dosing of ONO-5334 is more efficacious at reducing markers of bone turnover in healthy postmenopausal women than evening dosing. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01384188 , registered on June 27, 2011 EudraCT: 2008-006284-37.


Assuntos
Conservadores da Densidade Óssea/administração & dosagem , Reabsorção Óssea/prevenção & controle , Catepsina K/antagonistas & inibidores , Tiazolidinas/administração & dosagem , Idoso , Biomarcadores/sangue , Conservadores da Densidade Óssea/farmacologia , Conservadores da Densidade Óssea/uso terapêutico , Reabsorção Óssea/sangue , Reabsorção Óssea/fisiopatologia , Relógios Circadianos/fisiologia , Colágeno Tipo I/sangue , Estudos Cross-Over , Esquema de Medicação , Feminino , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/prevenção & controle , Peptídeos/sangue , Pós-Menopausa/sangue , Pós-Menopausa/fisiologia , Método Simples-Cego , Tiazolidinas/farmacologia , Tiazolidinas/uso terapêutico
3.
Int J Clin Pract ; 70(8): 676-81, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27396989

RESUMO

BACKGROUND AND AIMS: Dyspnoea is the most common symptom of chronic obstructive pulmonary disease (COPD) significantly affecting activity, impairing patients' well-being and contributing to the economic burden of COPD. The objective of this study was to estimate the prevalence of dyspnoea and its impact on COPD management costs in Japan. METHODS: A cross-sectional survey was conducted among 82 internal medicine physicians and 85 respiratory specialists representing 420 patients with COPD in Japan. Information was collected on demographic and clinical characteristics, dyspnoea (mMRC scale), and healthcare resource use. Dyspnoea prevalence was estimated among all patients and those on specific COPD treatments. The economic burden was derived from two cohorts based on their level of dyspnoea that were matched by propensity scores balancing their demographic and disease burden characteristics. RESULTS: Moderate-severe dyspnoea (mMRC score ≥ 2) was reported by 37.5% of COPD patients and ranging from 21.5% among patients treated with a mono bronchodilator to 59.8% among patients treated with triple therapy. Descriptive analysis showed that dyspnoeic patients have higher annual costs attributable to consultations (€2999 vs. €1906), medications (€1139 vs. €716), exacerbations (€674 vs. €36), other resources (€1789 vs. €140) and in total (€6348 vs. €2797) (p < 0.0001 for all comparisons) compared to patients with mild or no dyspnoea (mMRC score < 2). The total costs remained significantly higher in a propensity-matched cohort adjusted for severity and cardiovascular comorbidity [€6776.1 vs. €4461.3, p = 0.0236]. CONCLUSION: Moderate-severe dyspnoea is common among consulting COPD patients in Japan and is a significant cost driver for the healthcare system.


Assuntos
Dispneia/epidemiologia , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Idoso , Efeitos Psicossociais da Doença , Custos e Análise de Custo , Estudos Transversais , Dispneia/economia , Dispneia/terapia , Feminino , Recursos em Saúde/economia , Recursos em Saúde/estatística & dados numéricos , Humanos , Japão/epidemiologia , Masculino , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Prevalência , Doença Pulmonar Obstrutiva Crônica/economia , Doença Pulmonar Obstrutiva Crônica/terapia , Estudos Retrospectivos , Resultado do Tratamento
4.
J Urol ; 191(1): 253-60, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24018240

RESUMO

PURPOSE: We evaluated the efficacy, safety and tolerability of the EP1 receptor antagonist ONO-8539 in patients with overactive bladder syndrome. MATERIALS AND METHODS: This was a 12-week, randomized, double-blind, placebo controlled, parallel group, multicenter study with a 2-week single blind placebo run-in phase. The 435 patients were randomized to receive twice daily ONO-8539 (30, 100 or 300 mg), placebo or once daily tolterodine (4 mg). RESULTS: At the end of the 12-week treatment no statistically significant difference was found between ONO-8539 and placebo in the change from baseline in the number of micturitions per 24 hours. The primary end points for 30, 100 and 300 mg ONO-8539, and placebo were -1.02, -1.53, -1.31 and -1.40, respectively. There was no statistically significant difference between any ONO-8539 group and placebo in the change from baseline in the number of urgency or urinary urgency incontinence episodes per 24 hours, or the mean volume voided per micturition, which were secondary end points. Statistically significant differences for tolterodine vs placebo were observed in the change from baseline in the number of micturitions (p = 0.045), urgency episodes (p = 0.04) and mean volume voided per micturition (p <0.001). The incidence of adverse events was 54.1% in the placebo group, 43.0% to 54.0% in the ONO-8539 groups and 46.6% in the tolterodine group. The intensity of adverse events was similar among the treatment groups. Similar to other treatments, the most frequently reported adverse events after ONO-8539 were nasopharyngitis and diarrhea. CONCLUSIONS: The results of this study, which to our knowledge represents the first evaluation of ONO-8539 in patients with overactive bladder, suggest a minimal role for EP1 receptor antagonism in the management of overactive bladder syndrome.


Assuntos
Compostos Benzidrílicos/uso terapêutico , Cresóis/uso terapêutico , Fenilpropanolamina/uso terapêutico , Receptores de Prostaglandina E Subtipo EP1/antagonistas & inibidores , Bexiga Urinária Hiperativa/tratamento farmacológico , Agentes Urológicos/uso terapêutico , Adulto , Idoso , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tartarato de Tolterodina , Resultado do Tratamento
5.
Ann Oncol ; 24(12): 3061-5, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24146220

RESUMO

BACKGROUND: Current data suggest that chemotherapy combinations may be superior to single agents in biliary tract cancer. The epidermal growth factor receptor (EGFR) pathway appears to be associated with tumor stage, prognosis and response to therapy. This trial was designed to evaluate the tolerability and efficacy of the combination of panitumumab, a monoclonal anti-EGFR antibody, with gemcitabine and irinotecan. PATIENTS AND METHODS: Patients with advanced (unresectable or metastatic) cholangiocarcinoma, ECOG PS 0-2, and adequate organ function were treated with panitumumab (9 mg/kg) on day 1, and gemcitabine (1000 mg/m(2)) and irinotecan (100 mg/m(2)) on days 1 and 8 of a 21-day cycle. The primary objective was to evaluate the 5-month progression-free survival (PFS). Secondary objectives included overall response rate (ORR) and overall survival (OS). Mutational analyses of EGFR, KRAS and BRAF were carried out when feasible. RESULTS: Thirty-five patients received a median of 7 (0-30) cycles. The most common grade 3/4 toxic effects were neutropenia (10 patients, 29%), thrombocytopenia (10 patients, 29%), skin rash (13 patients, 37%) and dehydration (9 patients, 26%). Two patients had CR, 9 had partial response (PR), and 15 had SD for a disease-control rate of 74% (by RECIST) in 28 assessable patients. Two patients went on to have surgical resection. The 5-month PFS was 69%. The median PFS was 9.7 months and the median OS was 12.9 months. In 17 testable samples, no EGFR or BRAF mutations were identified; there were 7 KRAS mutations, with no difference in OS by KRAS status. CONCLUSIONS: This study showed encouraging efficacy of this regimen with good tolerability. Further study in this area is warranted. Clinical Trials Number: The trial was registered with the National Cancer Institute (www.clinicaltrials.gov identifier NCT00948935).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias dos Ductos Biliares/tratamento farmacológico , Colangiocarcinoma/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/administração & dosagem , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/mortalidade , Neoplasias dos Ductos Biliares/patologia , Camptotecina/administração & dosagem , Camptotecina/análogos & derivados , Colangiocarcinoma/genética , Colangiocarcinoma/mortalidade , Colangiocarcinoma/patologia , Análise Mutacional de DNA , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Intervalo Livre de Doença , Esquema de Medicação , Feminino , Humanos , Irinotecano , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Panitumumabe , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas p21(ras) , Resultado do Tratamento , Proteínas ras/genética , Gencitabina
7.
Educ Health (Abingdon) ; 25(1): 24-32, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23787381

RESUMO

BACKGROUND: Leadership development is a strategy for improving national responses to HIV/AIDS. The University of the West Indies offers the Caribbean Health Leadership Institute (CHLI) to enhance leaders' effectiveness and responses to HIV/AIDS through a cooperative agreement with the Centers for Disease Control and Prevention. CHLI enrolls leaders in annual cohorts numbering 20-40. OBJECTIVES: To examine how CHLI influenced graduates' self-understanding, skills, approaches, vision, commitments, courage, confidence, networks, and contributions to program, organizational, policy, and systems improvements. METHODS: Web-based surveys and interviews of graduates. RESULTS: CHLI increased graduates' self-understanding and skills and strengthened many graduates' vision, confidence, and commitments to improving systems. It helped graduates improve programs, policies, and systems by: motivating them and giving them ideas for changes to pursue, encouraging them to share their vision, deepening skills in areas such as systems thinking, policy advocacy, and communication, strengthening their inclusion of partners and team members, and influencing how they interacted with others. Training both HIV-focused and general health leaders can help both kinds of leaders foster improvements in HIV services and policies. DISCUSSION: Learners greatly valued self-assessments, highly interactive sessions, and the opportunity to build a network of professional colleagues. Projects provided opportunities to address substantive issues and immediately apply learning to work. Leadership development evaluations in the United States have also emphasized the complementary benefits of assessment and feedback, skills development, and network development. Global leadership programs should find ways to combine these components in both traditional face-to-face and distance-learning contexts.


Assuntos
Infecções por HIV/prevenção & controle , Liderança , Saúde Pública/educação , Região do Caribe/epidemiologia , Feminino , Infecções por HIV/terapia , Política de Saúde , Humanos , Masculino , Pandemias/prevenção & controle , Administração em Saúde Pública
8.
Diabetologia ; 54(7): 1799-809, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21455728

RESUMO

AIMS/HYPOTHESIS: The hypoglycaemic actions of metformin have been proposed to be mediated by hepatic AMP-activated protein kinase (AMPK). As the effects of metformin and the role of AMPK in adipose tissue remain poorly characterised, we examined the effect of metformin on AMPK activity in adipose tissue of individuals with type 2 diabetes in a randomised glycaemia-controlled crossover study. METHODS: Twenty men with type 2 diabetes (aged 50-70 years) treated with diet, metformin or sulfonylurea alone were recruited from North Glasgow University National Health Service Trusts' diabetes clinics and randomised to either metformin or gliclazide for 10 weeks. Randomisation codes, generated by computer, were put into sealed envelopes and stored by the hospital pharmacist. Medication bottles were numbered, and allocation was done in sequence. The participants and investigators were blinded to group assignment. At the end of each phase of therapy adipose biopsy, AMPK activity (primary endpoint) and levels of lipid metabolism and signalling proteins were assessed. In parallel, the effect of metformin on AMPK and insulin-signalling pathways was investigated in 3T3-L1 adipocytes. RESULTS: Ten participants were initially randomised to metformin and subsequently crossed over to gliclazide, while ten participants were initially randomised to gliclazide and subsequently crossed over to metformin. No participants discontinued the intervention and the adipose tissue AMPK activity was analysed in all 20 participants. There were no adverse events or side effects in the study group. Adipose AMPK activity was increased following metformin compared with gliclazide therapy (0.057 ± 0.007 vs 0.030 ± 0.005 [mean ± SEM] nmol min(-1) [mg lysate](-1); p < 0.005), independent of AMPK level, glycaemia or plasma adiponectin concentrations. The increase was associated with reduced levels of acetyl-CoA carboxylase (ACC) protein and increased ACC Ser80 phosphorylation. In 3T3-L1 adipocytes, metformin reduced levels of ACC protein and stimulated phosphorylation of AMPK Thr172 and hormone-sensitive lipase Ser565. CONCLUSIONS: These results provide the first evidence that metformin activates AMPK and reduces ACC protein levels in human adipose tissue in vivo. Future studies are required to assess the role of adipose AMPK activation in the pharmacological effects of metformin. TRIAL REGISTRATION: ISRCTN51336867.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/enzimologia , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Idoso , Estudos Cross-Over , Gliclazida/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade
9.
Curr Opin Cell Biol ; 5(2): 286-91, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8507500

RESUMO

Apoptosis, or programmed cell death, plays an essential role in specific cell deletion during normal embryonic and adult development in vertebrate and invertebrate species. Recent evidence suggests that signal transduction pathways governing cellular proliferation and cell cycle progression also mediate the physiological response to changes in the extracellular environment that trigger the anti-proliferative state characteristic of apoptosis.


Assuntos
Apoptose , Transdução de Sinais , Animais , Cálcio/metabolismo , Proteínas Quinases , Proto-Oncogenes , Fatores de Transcrição
10.
JPEN J Parenter Enteral Nutr ; 45(6): 1369-1375, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33586170

RESUMO

BACKGROUND: The direct effect of the coronavirus disease 2019 (COVID-19) pandemic on patients with intestinal failure (IF) has not been described. METHODS: We conducted a nationwide study of UK IF centers to evaluate the infection rates, presentations, and outcomes in patients with types 2 and 3 IF. RESULTS: A total of 45 patients with IF contracted COVID-19 between March and August 2020; this included 26 of 2191 (1.2%) home parenteral nutrition (HPN)-dependent adults and 19 of 298 (6.4%) adults hospitalized with type 2 IF. The proportion of patients receiving nursing care for HPN administration was higher in those with community-acquired COVID-19 (66.7%) than the proportion in the entire HPN cohort (26.1%; P < .01). Two HPN-dependent and 1 hospitalized patient with type 2 IF died as a direct consequence of the virus (6.7% of 45 patients with types 2 or 3 infected). CONCLUSION: This is the first study to describe the outcomes of COVID-19 in a large cohort of patients requiring long-term PN. Methods to reduce hospital and community nosocomial spread would likely be beneficial.


Assuntos
COVID-19 , Enteropatias , Nutrição Parenteral no Domicílio , Adulto , Humanos , Enteropatias/complicações , Enteropatias/terapia , Nutrição Parenteral no Domicílio/efeitos adversos , Estudos Retrospectivos , SARS-CoV-2 , Reino Unido/epidemiologia
11.
J Exp Med ; 132(5): 885-97, 1970 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-4394277

RESUMO

By means of an assay of graft-versus-host activity some properties of the thymic humoral factor which confers immunocompetence upon lymphoid cells in vitro have been studied. Allogeneic and xenogeneic thymic preparations were found to activate lymphoid cells from neonatally thymectomized mice, enabling initiation of a graft-versus-host response. Thus, this thymus factor is apparently neither strain nor species specific. The active principle of calf thymus extracts was found to be in the supernatant after prolonged ultracentrifugation. When exhaustive dialysis and ultrafiltration through Diaflo membranes were performed, the active thymus agent was found to pass through both the dialysis sac and Diaflo UM-2 membranes. The molecule which confers immunocompetence upon lymphoid cells thus seems to be of molecular weight of an order of magnitude of 1000 or less. Dialyzed thymus preparations injected into neonatally thymectomized mice also restored the capacity of spleen cells of these mice to induce graft-versus-host activity. When injected into intact mice, thymus extract also increased the proportion of competent cells in the spleens of these animals, probably by activation of target cells originating outside the spleen.


Assuntos
Linfócitos/imunologia , Timo/imunologia , Animais , Meios de Cultura , Diálise , Filtração , Reação Enxerto-Hospedeiro , Técnicas In Vitro , Camundongos , Especificidade da Espécie , Baço/imunologia , Timectomia , Extratos de Tecidos/administração & dosagem , Ultracentrifugação
12.
J Exp Med ; 134(3 Pt 1): 786-800, 1971 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-15776575

RESUMO

The hypothesis that cells located in mouse bone marrow can acquire immunological competence by a process that involves interaction with a noncellular component of the thymus was tested using an in vitro assay of graft-versus-host reactivity as a criterion of cell competence. When suspensions of C57BL bone marrow cells were incubated in thymus extract and injected into mice incapable of inducing a response in the graft-versus-host assay as a result of neonatal thymectomy, or adult thymectomy plus irradiation, or because of genetic similarity with the (C3H x C57BL)F(1) tissue used for challenge in the assay, competent cells were recovered from the spleens of the injected mice. The reactive cells were shown to be of bone marrow origin since immune reactivity was related to the genetic makeup of the bone marrow cells rather than that of the intermediate recipients. A thymic factor was involved in the process leading to immune reactivity by these cells, as bone marrow cells incubated in xenogeneic or syngeneic thymic extracts induced a graft-versus-host response after passage through nonresponsive mice, whereas incubation of bone marrow cells in xenogeneic lymph node or spleen extracts or in culture medium only did not lead to subsequent reactivity. Participation of peripheral lymphoid tissue seemed essential in this process since bone marrow cells tested directly after exposure to thymic extract failed to induce a graft-versus-host response. C57BL bone marrow cells exposed to thymus extract and cultured together with fragments of (C3H x C57BL)F(1) spleen tissue in vitro were competent to induce a graft-versus-host response; thus, these components would seem to be sufficient as well as necessary for the immunodifferentiation process leading to graft-versus-host activity. It is concluded that one step in the process by which bone marrow cells acquire competence vis-a-vis the graft-versus-host response depends upon a thymic agent that is noncellular and extractable, and that another stage in this process is under the influence of components found within the peripheral lymphoid tissue environment. It is suggested that differentiation of precursor cells to competence could occur by progressive development of the cells in separate compartments of the lymphoid system.


Assuntos
Células da Medula Óssea/imunologia , Linfócitos/imunologia , Timo/fisiologia , Animais , Reação Enxerto-Hospedeiro , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL
13.
J Exp Med ; 130(4): 765-75, 1969 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-4390489

RESUMO

Impaired immunological competence of spleen cells from neonatally thymectomized C57B1/6 young adult mice was apparent when these cells were tested in an in vitro graft-versus-host assay. Spleen cell inocula prepared from thymectomized mice did not induce enlargement of (C3H/eb x C57BI/6)F(1) newborn spleen explants, whereas the same number of cells from intact donors consistently initiated splenomegaly. Spleen enlargement was observed, however, when the explants were challenged by cells from thymectomized donors in the presence of syngeneic thymus extract, indicating that the spleen cells in suspension attained immunological competence under the influence of a non-cellular component of the thymus. Immunocompetence was also evident when the cells from thymectomized donors were first incubated with thymus extract for 1 hr and subsequently tested for reactivity. Cells from the same thymectomized donor mice exposed in parallel to extracts from syngeneic spleen or mesenteric lymph node at an equivalent protein concentration did not initiate a graft-versus-host response. These experiments demonstrate that immune reactivity in the graft-versus-host response involves activation of lymphoid cells by a humoral factor of the thymus acting directly upon these cells.


Assuntos
Reação Enxerto-Hospedeiro , Baço/imunologia , Timo/imunologia , Envelhecimento , Animais , Animais Recém-Nascidos , Doença Enxerto-Hospedeiro/prevenção & controle , Técnicas In Vitro , Camundongos , Baço/citologia , Timectomia , Timo/transplante , Extratos de Tecidos/farmacologia , Transplante Homólogo
14.
J Exp Med ; 176(2): 543-51, 1992 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-1386875

RESUMO

We have investigated the ability of a heterogeneous thymic stromal cell (HTSC) culture system to promote in vitro differentiation of CD3-4-8- thymocytes. Culture of purified murine CD3-4-8- thymocytes on HTSC for 1 d resulted in the appearance of CD4+8+ cells, which did not occur when the sorted cells were maintained in medium alone. It is remarkable that when the culture period was extended to 2 d, CD3-4-8- progenitors differentiated further to CD4+8- and CD4-8+ cells, which also expressed high levels of TCR-CD3. This rapid differentiation on stroma in vitro appears to outpace parallel development in vivo. The differentiation potential of a subset of CD3-4-8- thymocytes that express high levels of a marker of normal and neoplastic thymic progenitors, the 1C11 antigen, was examined next. 1C11hiCD3-4-8- cells also gave rise to CD4-8+ and CD4+8+ populations after 1 d of culture on HTSC. Extending the culture period to 2 d resulted in a significant percentage of CD3-expressing cells that were CD4+8+, CD4+8- and CD4-8+ cells. These results suggest that in the in vitro HTSC culture system, various subsets of immature thymocytes can differentiate into all the mature phenotypes of cells normally found in the adult mouse thymus. This may provide a novel and rapid assay for thymic progenitors.


Assuntos
Antígenos CD/metabolismo , Timo/citologia , Animais , Antígenos de Diferenciação de Linfócitos T/metabolismo , Complexo CD3 , Antígenos CD4/metabolismo , Antígenos CD8/metabolismo , Diferenciação Celular , Células Cultivadas , Citometria de Fluxo , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Antígenos de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Timo/imunologia
15.
Genetica ; 138(3): 387-93, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20128114

RESUMO

If alternative phenotypes in polymorphic populations do not mate randomly, they can be used as model systems to study adaptive diversification and possibly the early stages of sympatric speciation. In this case, non random mating is expected to support genetic divergence among the different phenotypes. In the present study, we use population genetic analyses to test putatively neutral genetic divergence (of microsatellite loci) among three colour morphs of the lizard Podarcis melisellensis, which is associated with differences in male morphology, performance and behaviour. We found weak evidence of genetic divergence, indicating that gene flow is somewhat restricted among morphs and suggesting possible adaptive diversification.


Assuntos
Variação Genética , Lagartos/genética , Pigmentação , Animais , DNA/análise , DNA/genética , Evolução Molecular , Feminino , Fluxo Gênico , Especiação Genética , Genética Populacional , Genoma , Masculino , Preferência de Acasalamento Animal , Repetições de Microssatélites/genética , Fatores Sexuais , Especificidade da Espécie
17.
Mol Cell Biol ; 13(4): 2432-40, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8455620

RESUMO

The product of the c-myc proto-oncogene is an important positive regulator of cell growth and proliferation. Recently, c-Myc has also been demonstrated to be a potent inducer of apoptosis when expressed in the absence of serum or growth factors. To further examine Myc-induced apoptosis, we coexpressed the proto-oncogene bcl2, which has been shown to block apoptosis in other systems, with c-myc in serum-deprived Rat 1a fibroblasts. Here we report that ectopic expression of bcl2 specifically blocks apoptosis induced by constitutive c-myc expression. Constitutive c-myc expression in serum-deprived Rat 1a cells caused a > 15-fold increase in the number of dead cells, accompanied by DNA fragmentation. However, coexpression of bcl2 with c-myc in these cells led to a 10-fold increase in the number of live cells and a significant decrease in DNA fragmentation. Thus, Bcl-2 effectively inhibits Myc-induced apoptosis in serum-deprived Rat 1a fibroblasts without blocking entry into the cell cycle. These results imply that apoptosis serves as a protective mechanism to prevent tumorigenicity elicited by deregulated Myc expression. This protective mechanism is abrogated, however, by Bcl-2 and therefore may explain the synergism between Myc and Bcl-2 observed in certain tumor cells.


Assuntos
Apoptose , Genes myc , Proteínas Proto-Oncogênicas c-myc/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Animais , Ciclo Celular , Células Cultivadas , Meios de Cultura , Dano ao DNA , Expressão Gênica , Vetores Genéticos , Técnicas In Vitro , Proteínas Proto-Oncogênicas c-bcl-2 , RNA Mensageiro/genética , Ratos , Retroviridae , Transfecção
18.
Mol Cell Biol ; 7(5): 1638-45, 1987 May.
Artigo em Inglês | MEDLINE | ID: mdl-3299052

RESUMO

Amplification and abundant expression of a gene known as N-myc are found frequently in advanced stages of human neuroblastoma and may play a role in the genesis of several malignant human tumors. Previous studies have shown that N-myc can cooperate with a mutant allele of the proto-oncogene c-Ha-ras to transform embryonic rat cells in culture. Here we show that N-myc can also act alone to elicit neoplastic growth of an established line of rat fibroblasts (Rat-1). We used recombinant DNA vectors to express either N-myc or its kindred gene c-myc in transfected cells. Both genes caused morphological transformation, anchorage-independent growth, and tumorigenicity. We noticed two variables that appeared to influence the ability to isolate cells transformed by N-myc and c-myc: the abundance in which the genes were expressed and biological selection to eliminate untransformed cells from the cultures. Our findings sustain the belief that N-myc is an authentic proto-oncogene, lend further credibility to the role of N-myc in the genesis of human tumors, and establish a convenient assay that can be used to explore further the properties of both N-myc and c-myc.


Assuntos
Transformação Celular Neoplásica , Neoplasias Experimentais/genética , Oncogenes , Proto-Oncogenes , Animais , Divisão Celular , Linhagem Celular , Fibroblastos , Regulação da Expressão Gênica , Vetores Genéticos , Humanos , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/genética , Ratos , Transfecção
19.
Philos Trans A Math Phys Eng Sci ; 375(2096)2017 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-28507237

RESUMO

In this study, we propose a new information theoretic measure to quantify the complexity of biological systems based on time-series data. We demonstrate the potential of our method using two distinct applications to human cardiac dynamics. Firstly, we show that the method clearly discriminates between segments of electrocardiogram records characterized by normal sinus rhythm, ventricular tachycardia and ventricular fibrillation. Secondly, we investigate the multiscale complexity of cardiac dynamics with respect to age in healthy individuals using interbeat interval time series and compare our findings with a previous study which established a link between age and fractal-like long-range correlations. The method we use is an extension of the symbolic mapping procedure originally proposed for permutation entropy. We build a Markov chain of the dynamics based on order patterns in the time series which we call an ordinal network, and from this model compute an intuitive entropic measure of transitional complexity. A discussion of the model parameter space in terms of traditional time delay embedding provides a theoretical basis for our multiscale approach. As an ancillary discussion, we address the practical issue of node aliasing and how this effects ordinal network models of continuous systems from discrete time sampled data, such as interbeat interval time series.This article is part of the themed issue 'Mathematical methods in medicine: neuroscience, cardiology and pathology'.


Assuntos
Envelhecimento , Arritmias Cardíacas/fisiopatologia , Eletrocardiografia/métodos , Determinação da Frequência Cardíaca/métodos , Frequência Cardíaca , Modelos Cardiovasculares , Arritmias Cardíacas/diagnóstico , Simulação por Computador , Interpretação Estatística de Dados , Humanos , Cadeias de Markov , Modelos Estatísticos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Phys Rev E Stat Nonlin Soft Matter Phys ; 73(1 Pt 2): 016216, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16486267

RESUMO

A different method is proposed to detect deterministic structure from a pseudoperiodic time series. By using the correlation coefficient as a measure of the distance between cycles, we are exempt from phase-space reconstruction and further construct a hierarchy of pseudocycle series that, in turn, preserve less determinism than the original time series. Appropriate statistics are then devised to reveal the temporal and spatial correlation encoded in this hierarchy of the pseudocycle series, which allows for a reliable detection of determinism and chaos in the original time series. We demonstrate that this method can reliably identify chaos in the presence of noise of different sources for both artificial data and experimental time series.

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