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1.
Artigo em Inglês | MEDLINE | ID: mdl-38397649

RESUMO

To compare different criteria for the diagnosis of periodontitis and to evaluate the association of this condition with prematurity, this case-control study was conducted on 283 mothers of infants, divided into two groups based on gestational age (cases: <37 weeks, controls: ≥37 weeks), with 71 cases and 212 controls. The periodontal evaluation included probing depth (PD), clinical attachment level (CAL), plaque index, and bleeding on probing (BOP). Participants were classified regarding periodontitis per 14 criteria based on different periodontal parameters. The criterion selected as the gold standard was the presence of at least four teeth with one or more sites with a PD ≥ 4 mm, CAL ≥ 3 mm, and BOP at the same site. The prevalence of periodontal disease ranged from 8.1% to 55.1%. Moreover, compared to the gold standard, the sensitivities of the other criteria were 100%, while specificity ranged from 50.4% to 96.4%. Periodontitis, defined by six of the selected criteria, was associated with prematurity after multivariate adjustment, with OR ranging from 1.85 to 2.69 and 95% CI from 1.01 to 5.56; one of them was the gold standard mentioned above. Measurements using the clinical parameters of PD, CAL, and bleeding at the same site (criteria 5, 6, 7, 8), CPI (criterion 10), and at least four teeth with a PD ≥ 4 mm and CAL ≥ 3 mm (criterion 11) to define periodontitis showed a statistically significant association (p < 0.05). Given this study's limitations, we can conclude that the diagnostic criteria for a periodontitis definition using a PD ≥ 4 mm and CAL ≥ 3 mm in two or more teeth, with BOP at the same site, seem stronger when detecting an association between periodontitis and prematurity.


Assuntos
Doenças Periodontais , Periodontite , Feminino , Humanos , Recém-Nascido , Lactente , Estudos de Casos e Controles , Recém-Nascido Prematuro , Periodontite/diagnóstico , Periodontite/epidemiologia , Periodontite/complicações , Doenças Periodontais/complicações , Mães
2.
Oral Dis ; 2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37884359

RESUMO

OBJECTIVE: To analyze prenatal and perinatal stressors associated with molar incisor hypomineralization (MIH) in adolescents. METHODS: Prospective cohort study collected prenatal (socioeconomic status, maternal age, number of prenatal visits, smoking, obesity during pregnancy, abortion history, gestational hypertension) and perinatal stressors (type of delivery, gestational age, birth weight, intensive care unit-ICU at birth). The outcome was MIH at 18-19 years follow-up (n = 590). MIH was defined according to the Ghanim criteria - Model I. We performed a sensitivity analysis, including opacities demarcated in index tooth, incisive or molars, Model II. Through structural equation modeling, we analyzed direct and mediating pathways between multiple stressors with outcomes. RESULTS: MIH was observed in 15.25% (n = 90), and opacities demarcated in any index tooth were observed in 22.8% of adolescents (n = 135). In Model I, no stressor explained MIH significantly, although we watched high standardized coefficients (SC) for low birth weight (SC = 0.223, p = 0.147), lower gestational age (SC = 0.351; p = 0.254), and ICU admission (SC = 0.447, p = 0.254). In Model II, advanced maternal age (SC = 0.148; p < 0.05) and not undergoing prenatal care (SC = 0.384, p < 0.03) explained opacities demarcated in incisors or molars. CONCLUSION: Advanced maternal age and not undergoing prenatal care were associated with MIH lesion-like in incisors or molars.

4.
Cancer Res Commun ; 2(3): 182-201, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-36874405

RESUMO

Deregulated expression of MYC family oncogenes occurs frequently in human cancer and is often associated with aggressive disease and poor prognosis. While MYC is a highly warranted target, it has been considered "undruggable," and no specific anti-MYC drugs are available in the clinic. We recently identified molecules named MYCMIs that inhibit the interaction between MYC and its essential partner MAX. Here we show that one of these molecules, MYCMI-7, efficiently and selectively inhibits MYC:MAX and MYCN:MAX interactions in cells, binds directly to recombinant MYC, and reduces MYC-driven transcription. In addition, MYCMI-7 induces degradation of MYC and MYCN proteins. MYCMI-7 potently induces growth arrest/apoptosis in tumor cells in a MYC/MYCN-dependent manner and downregulates the MYC pathway on a global level as determined by RNA sequencing. Sensitivity to MYCMI-7 correlates with MYC expression in a panel of 60 tumor cell lines and MYCMI-7 shows high efficacy toward a collection of patient-derived primary glioblastoma and acute myeloid leukemia (AML) ex vivo cultures. Importantly, a variety of normal cells become G1 arrested without signs of apoptosis upon MYCMI-7 treatment. Finally, in mouse tumor models of MYC-driven AML, breast cancer, and MYCN-amplified neuroblastoma, treatment with MYCMI-7 downregulates MYC/MYCN, inhibits tumor growth, and prolongs survival through apoptosis with few side effects. In conclusion, MYCMI-7 is a potent and selective MYC inhibitor that is highly relevant for the development into clinically useful drugs for the treatment of MYC-driven cancer. Significance: Our findings demonstrate that the small-molecule MYCMI-7 binds MYC and inhibits interaction between MYC and MAX, thereby hampering MYC-driven tumor cell growth in culture and in vivo while sparing normal cells.


Assuntos
Neuroblastoma , Animais , Camundongos , Humanos , Proteína Proto-Oncogênica N-Myc/genética , Linhagem Celular Tumoral , Neuroblastoma/tratamento farmacológico , Proliferação de Células , Ciclo Celular
5.
Elife ; 92020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32628111

RESUMO

Inhibition of WEE1 kinase by AZD1775 has shown promising results in clinical cancer trials, but markers predicting AZD1775 response are lacking. Here we analysed AZD1775 response in a panel of human breast cancer (BC) cell lines by global proteome/transcriptome profiling and identified two groups of basal-like BC (BLBCs): 'PTEN low' BLBCs were highly sensitive to AZD1775 and failed to recover following removal of AZD1775, while 'PTEN high' BLBCs recovered. AZD1775 induced phosphorylation of DNA-PK, protecting cells from replication-associated DNA damage and promoting cellular recovery. Deletion of DNA-PK or PTEN, or inhibition of DNA-PK sensitized recovering BLBCs to AZD1775 by abrogating replication arrest, allowing replication despite DNA damage. This was linked to reduced CHK1 activation, increased cyclin E levels and apoptosis. In conclusion, we identified PTEN and DNA-PK as essential regulators of replication checkpoint arrest in response to AZD1775 and defined PTEN as a promising biomarker for efficient WEE1 cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Proteínas de Ciclo Celular/genética , Proteína Quinase Ativada por DNA/genética , PTEN Fosfo-Hidrolase/genética , Proteínas Tirosina Quinases/genética , Pirazóis/farmacologia , Pirimidinonas/farmacologia , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proteína Quinase Ativada por DNA/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , PTEN Fosfo-Hidrolase/metabolismo , Proteínas Tirosina Quinases/metabolismo , Proteoma
6.
Rev. Bras. Saúde Mater. Infant. (Online) ; 20(2): 451-458, Apr.-June 2020. tab, graf
Artigo em Inglês | Sec. Est. Saúde SP, LILACS | ID: biblio-1136435

RESUMO

Abstract Objectives: to evaluate the effects of nifedipine with tocolysis under maternal and fetal parameters. Methods: a cohort study with 40 pregnant women admitted at a high-risk pregnancy ward to inhibit premature labor between September/2010 to May/2012. Nifedipine was used as a 20mg sublingual attack dose and maintained 20mg every six and eight hours orally. The variables of the analysis were fetal heart rate (FHR), maternal heart rate (MHR), systolic blood pressure (SBP) and diastolic blood pressure (DBP), and amniotic fluid index (AFI). All the variables were evaluated prior to administrating nifedipine and approximately after 6 hours and every 24 hours, until hospital discharge. Results: there were no modification of the FHR (p=0.48) and the SBP (p=0.29). The MHR increased after 24 hours, but with no statistical difference (p=0.08), returning to similar levels as at admission within 48 hours. The DBP decreased at 6 (p=0.04) to 72 hours, being stable afterwards. The AFI decreased significantly at 24, 48 and 72 hours. Conclusions: the use of high doses of nifedipine with tocolysis causes a decrease of the maternal's diastolic blood pressure and consequently decreases the amniotic fluid index, but probably without any clinical repercussions.


Resumo Objetivos: avaliar os efeitos da nifedipina utilizada na tocólise sobre os parâmetros maternos e fetais. Métodos: estudo de coorte incluindo 40 gestantes admitidas na enfermaria de alto risco para inibição do trabalho de parto prematuro entre setembro/2010 a maio/2012. Utilizou-se a nifedipina sublingual na dose de ataque de 20mg e uma manutenção de 20mg por via oral a cada seis e oito horas. As variáveis avaliadas foram os batimentos cardio-fetais (BCF), frequência cardíaca materna (FCM), pressão arterial sistólica (PAS) e diastólica (PAD) e índice de líquido amniótico (ILA). Todas as variáveis foram avaliadas antes da administração da nifedipina e aproximadamente após 6h e cada 24h até alta hospitalar. Resultados: não houve modificação dos BCF (p=0,48) e da PAS (p=0,29). A FCM aumentou após 24h, mas sem significância estatística (p=0,08) retornando a níveis similares ao da admissão com 48h. A PAD diminuiua partir de 6h (p = 0,04)até 72h, mantendo-se constante. O ILA diminuiu significativamente em 24h, 48h e 72h. Conclusão: a utilização de altas doses de nifedipina para tocóliseocasio na diminuição dos níveis pressóricos diastólicos maternos e consequentemente diminuição do ILA, mas provavelmente sem repercussões clínicas.


Assuntos
Humanos , Feminino , Gravidez , Nifedipino/administração & dosagem , Tocólise/métodos , Ultrassonografia Pré-Natal , Líquido Amniótico/diagnóstico por imagem , Trabalho de Parto Prematuro , Estudos de Coortes , Gravidez de Alto Risco
7.
Cien Saude Colet ; 25(3): 1157-1166, 2020 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-32159683

RESUMO

This study sought to perceive the concept of mental health from the perspective of Colombian indigenous peoples. A qualitative survey from a historic-hermeneutical standpoint was conducted by means of interviews with a stratified intentional sample of 10 leaders with experience in indigenous mental health. After being duly transcribed, interview materials were analyzed using a grounded theory approach. Findings were structured around four analytical categories: mental health perspectives, elements, scenarios, and challenges. It was revealed that some indigenous people do not perceive mental health as an indigenous concept. Some perceive it from a morbicentric western perspective and others from an ancestral holistic standpoint. They describe positive elements (good living, spirituality, harmony with mother earth) and negative aspects (acculturation, discrimination, violence, disobedience). Mental health scenarios included the land itself and the health care system, in particular the Intercultural Indigenous Health System (SISPI). Challenges include the need to conduct more research on this topic, consolidating SISPI, and fostering ancestral knowledge.


Este estudio tuvo como objetivo comprender el concepto de salud mental desde la perspectiva de los pueblos indígenas de Colombia. Se realizó una investigación con enfoque cualitativo, de tipo histórico hermenéutico a través de entrevistas a una muestra intencional estratificada de 10 líderes con experiencia en el tema de salud indígena. Luego de transcritas, se realizó el análisis de las entrevistas con herramientas de la teoría fundada. Los hallazgos se centraron en cuatro categorías analíticas: perspectivas de la salud mental, elementos, escenarios y retos. Se encontró que algunos indígenas no asumen la salud mental como un concepto propio. Entre los restantes, algunos lo asumen desde una perspectiva occidental morbicéntrica y los demás desde una perspectiva ancestral holística. Se describen elementos positivos (buen vivir, espiritualidad, armonía con la madre tierra) y negativos (aculturación, discriminación, violencia, desobediencia). Los escenarios de la salud mental que mencionaron los participantes son el territorio y el sistema de salud, en particular el Sistema Indígena de Salud Propio e Intercultural- SISPI. Los retos incluyen la necesidad de generar más investigaciones en este tema, el avance en la consolidación del SISPI y el fortalecimiento de los saberes ancestrales.


Assuntos
Povos Indígenas/psicologia , Saúde Mental , Colômbia , Características Culturais , Feminino , Humanos , Masculino
8.
Ciênc. Saúde Colet. (Impr.) ; 25(3): 1157-1166, mar. 2020. tab
Artigo em Espanhol | LILACS | ID: biblio-1089466

RESUMO

Resumen Este estudio tuvo como objetivo comprender el concepto de salud mental desde la perspectiva de los pueblos indígenas de Colombia. Se realizó una investigación con enfoque cualitativo, de tipo histórico hermenéutico a través de entrevistas a una muestra intencional estratificada de 10 líderes con experiencia en el tema de salud indígena. Luego de transcritas, se realizó el análisis de las entrevistas con herramientas de la teoría fundada. Los hallazgos se centraron en cuatro categorías analíticas: perspectivas de la salud mental, elementos, escenarios y retos. Se encontró que algunos indígenas no asumen la salud mental como un concepto propio. Entre los restantes, algunos lo asumen desde una perspectiva occidental morbicéntrica y los demás desde una perspectiva ancestral holística. Se describen elementos positivos (buen vivir, espiritualidad, armonía con la madre tierra) y negativos (aculturación, discriminación, violencia, desobediencia). Los escenarios de la salud mental que mencionaron los participantes son el territorio y el sistema de salud, en particular el Sistema Indígena de Salud Propio e Intercultural- SISPI. Los retos incluyen la necesidad de generar más investigaciones en este tema, el avance en la consolidación del SISPI y el fortalecimiento de los saberes ancestrales.


Abstract This study sought to perceive the concept of mental health from the perspective of Colombian indigenous peoples. A qualitative survey from a historic-hermeneutical standpoint was conducted by means of interviews with a stratified intentional sample of 10 leaders with experience in indigenous mental health. After being duly transcribed, interview materials were analyzed using a grounded theory approach. Findings were structured around four analytical categories: mental health perspectives, elements, scenarios, and challenges. It was revealed that some indigenous people do not perceive mental health as an indigenous concept. Some perceive it from a morbicentric western perspective and others from an ancestral holistic standpoint. They describe positive elements (good living, spirituality, harmony with mother earth) and negative aspects (acculturation, discrimination, violence, disobedience). Mental health scenarios included the land itself and the health care system, in particular the Intercultural Indigenous Health System (SISPI). Challenges include the need to conduct more research on this topic, consolidating SISPI, and fostering ancestral knowledge.


Assuntos
Humanos , Masculino , Feminino , Saúde Mental , Colômbia , Características Culturais , Povos Indígenas/psicologia
9.
Repert. med. cir ; 29((Núm. Supl.1.)): 22-26, 2020. tab.
Artigo em Inglês, Espanhol | COLNAL, LILACS | ID: biblio-1118357

RESUMO

El mundo vive una pandemia por un Coronavirus, llamado SARS-COV-2, que produce la COVID-19 (acrónimo del ingles coronavirus disease 2019), la cual ha generado un colapso en los sistemas de salud, haciendo que el manejo de otras enfermedades se convierta en un reto. De igual forma para los grupos oncológicos, la presencia de esta enfermedad, genera muchas dudas en la aplicación de los tratamientos estándares, los cuales se deben realizar lo antes posible, con el fin de ofrecer mejores resultados oncológicos. Se propone la creación de un índice ( COVID-19 Cáncer Index) , teniendo en cuenta variables clínicas, epidemiológicas y la disponibilidad de los recursos hospitalarios, útil para la toma de decisiones y el establecimiento del mejor tratamiento para una paciente con confirmación o alta sospecha de neoplasia ginecológica.


The world is experiencing a coronavirus pandemic called SARS-COV-2 which causes coronavirus disease 2019 (COVID 19). This has led to a collapse in health systems, making the management of other diseases a challenge. Similarly, the presence of this disease generates many doubts for oncological groups regarding the provision of standard treatments, which should be carried out as soon as possible, in order to ensure better oncological outcomes. We propose the creation of an index (COVID 19 Cancer Index) taking into account clinical and epidemiological variables and the availability of hospital resources, which are useful for decision making and determining the best treatment for a patient with confirmed or strongly suspected gynecological neoplasia.


Assuntos
Humanos , Infecções por Coronavirus , Neoplasias dos Genitais Femininos , Pandemias , Oncologia , Neoplasias
10.
Sci Rep ; 9(1): 2379, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30787419

RESUMO

Despite the widening range of high-throughput platforms and exponential growth of generated data volume, the validation of biomarkers discovered from large-scale data remains a challenging field. In order to tackle cancer heterogeneity and comply with the data dimensionality, a number of network and pathway approaches were invented but rarely systematically applied to this task. We propose a new method, called NEAmarker, for finding sensitive and robust biomarkers at the pathway level. scores from network enrichment analysis transform the original space of altered genes into a lower-dimensional space of pathways. These dimensions are then correlated with phenotype variables. The method was first tested using in vitro data from three anti-cancer drug screens and then on clinical data of The Cancer Genome Atlas. It proved superior to the single-gene and alternative enrichment analyses in terms of (1) universal applicability to different data types with a possibility of cross-platform integration, (2) consistency of the discovered correlates between independent drug screens, and (3) ability to explain differential survival of treated patients. Our new screen of anti-cancer compounds validated the performance of multivariate models of drug sensitivity. The previously proposed methods of enrichment analysis could achieve comparable levels of performance in certain tests. However, only our method could discover predictors of both in vitro response and patient survival given administration of the same drug.


Assuntos
Antineoplásicos/uso terapêutico , Biomarcadores/metabolismo , Biologia Computacional/métodos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Neoplasias/tratamento farmacológico , Linhagem Celular , Desenvolvimento de Medicamentos/métodos
11.
Sci Rep ; 8(1): 10064, 2018 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-29968736

RESUMO

MYC is a key player in tumor development, but unfortunately no specific MYC-targeting drugs are clinically available. MYC is strictly dependent on heterodimerization with MAX for transcription activation. Aiming at targeting this interaction, we identified MYCMI-6 in a cell-based protein interaction screen for small inhibitory molecules. MYCMI-6 exhibits strong selective inhibition of MYC:MAX interaction in cells and in vitro at single-digit micromolar concentrations, as validated by split Gaussia luciferase, in situ proximity ligation, microscale thermophoresis and surface plasmon resonance (SPR) assays. Further, MYCMI-6 blocks MYC-driven transcription and binds selectively to the MYC bHLHZip domain with a KD of 1.6 ± 0.5 µM as demonstrated by SPR. MYCMI-6 inhibits tumor cell growth in a MYC-dependent manner with IC50 concentrations as low as 0.5 µM, while sparing normal cells. The response to MYCMI-6 correlates with MYC expression based on data from 60 human tumor cell lines and is abrogated by MYC depletion. Further, it inhibits MYC:MAX interaction, reduces proliferation and induces massive apoptosis in tumor tissue from a MYC-driven xenograft tumor model without severe side effects. Since MYCMI-6 does not affect MYC expression, it is a unique molecular tool to specifically target MYC:MAX pharmacologically and it has good potential for drug development.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/antagonistas & inibidores , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Diaminas/farmacologia , Proteínas Proto-Oncogênicas c-myc/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-myc/metabolismo , Piridinas/farmacologia , Animais , Apoptose/fisiologia , Células COS , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Chlorocebus aethiops , Ensaios de Seleção de Medicamentos Antitumorais , Células HEK293 , Células HeLa , Ensaios de Triagem em Larga Escala/métodos , Humanos , Células MCF-7 , Camundongos , Camundongos Nus , Ligação Proteica/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Ativação Transcricional , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Nat Commun ; 9(1): 2071, 2018 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-29789663

RESUMO

The original PDF version of this Article listed the authors as "Marcus J.G.W. Ladds," where it should have read "Marcus J. G. W. Ladds, Ingeborg M. M. van Leeuwen, Catherine J. Drummond et al.#".Also in the PDF version, it was incorrectly stated that "Correspondence and requests for materials should be addressed to S. Lín.", instead of the correct "Correspondence and requests for materials should be addressed to S. Laín."This has been corrected in the PDF version of the Article. The HTML version was correct from the time of publication.

13.
Nat Commun ; 9(1): 1107, 2018 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-29549331

RESUMO

The development of non-genotoxic therapies that activate wild-type p53 in tumors is of great interest since the discovery of p53 as a tumor suppressor. Here we report the identification of over 100 small-molecules activating p53 in cells. We elucidate the mechanism of action of a chiral tetrahydroindazole (HZ00), and through target deconvolution, we deduce that its active enantiomer (R)-HZ00, inhibits dihydroorotate dehydrogenase (DHODH). The chiral specificity of HZ05, a more potent analog, is revealed by the crystal structure of the (R)-HZ05/DHODH complex. Twelve other DHODH inhibitor chemotypes are detailed among the p53 activators, which identifies DHODH as a frequent target for structurally diverse compounds. We observe that HZ compounds accumulate cancer cells in S-phase, increase p53 synthesis, and synergize with an inhibitor of p53 degradation to reduce tumor growth in vivo. We, therefore, propose a strategy to promote cancer cell killing by p53 instead of its reversible cell cycle arresting effect.


Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Indazóis/farmacologia , Neoplasias/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Di-Hidro-Orotato Desidrogenase , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Neoplasias/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Proteólise/efeitos dos fármacos , Proteína Supressora de Tumor p53/genética
14.
Artigo em Inglês | MEDLINE | ID: mdl-27705753

RESUMO

Mammals of the Neotropics are characterized by a marked annual cycle of activity, which is accompanied by several physiological changes at the levels of the whole organism, organs and tissues. The physiological characterization of these cycles is important, as it gives insight on the mechanisms by which animals adjust adaptively to seasonality. Here we studied the seasonal changes in blood biochemical parameters in the relict South American marsupial Dromiciops gliroides ("monito del monte" or "little mountain monkey"), under semi-natural conditions. We manipulated thermal conditions in order to characterize the effects of temperature and season on a battery of biochemical parameters, body mass and adiposity. Our results indicate that monitos experience an annual cycle in body mass and adiposity (measured as leptin levels), reaching a maximum in winter and a minimum in summer. Blood biochemistry confirms that the nutritional condition of animals is reduced in summer instead of winter (as generally reported). This was coincident with a reduction of several biochemical parameters in summer, such as betahydroxybutyrate, cholesterol, total protein concentration and globulins. Monitos seem to initiate winter preparation during autumn and reach maximum body reserves in winter. Hibernation lasts until spring, at which time they use fat reserves and become reproductively active. Sexual maturation during summer would be the strongest energetic bottleneck, which explains the reductions in body mass and other parameters in this season. Overall, this study suggests that monitos anticipate the cold season by a complex interaction of photoperiodic and thermal cues.


Assuntos
Aclimatação , Adiposidade , Leptina/sangue , Marsupiais/fisiologia , Estado Nutricional , Ácido 3-Hidroxibutírico/sangue , Animais , Chile , Colesterol/sangue , Hibernação , Marsupiais/sangue , Marsupiais/crescimento & desenvolvimento , Fotoperíodo , Estações do Ano , Soroglobulinas/análise , Aumento de Peso , Redução de Peso
15.
J Contemp Dent Pract ; 16(5): 376-82, 2015 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-26162257

RESUMO

OBJECTIVE: To evaluate the effect of 3% phosphate ascorbyl gel (PA) in different times onto the microshear bond strength of composite resin (CR) to bovine enamel treated with 35% hydrogen peroxide (HP). MATERIALS AND METHODS: Thirty enamel blocks of bovine incisors were made and divided into 5 groups (n = 6) with three specimens per group (n = 18), according to treatment: G1= No bleaching + CR; G2 = HP + CR after 15d; G3 = HP + CR after 24 hours; G4 = HP + PA (15 min) + CR after 24 hours; G5 = HP + PA (2 hours) + CR after 24 hours. The resin cylinders were made by Tygon matrices. Microshear bond strength test was performed using universal testing machine with a 50N load at a speed of 0.5 mm/min. Fracture modes were assessed by a stereomicroscope 40 ×. Microshear bond strength values were submitted to the analysis of variance (ANOVA) one-way and Tukey test (p < 0.05). RESULTS: G1 had significant results when compared to G3 and G5 (p < 0.01). However, G2, G3, G4 and G5 have showed no significant differences among groups (p > 0.05). Failure modes were categorized into adhesive (90%) and mixed (10%). CONCLUSION: The use of 3% phosphate ascorbyl gel for 15 minutes was able to improve bond strength of composite resin to bleached bovine enamel, but when 3% phosphate ascorbyl gel was applied during 40 minutes it negatively interfered in the adhesion of the resin to bleached bovine enamel.


Assuntos
Antioxidantes/química , Ácido Ascórbico/análogos & derivados , Resinas Compostas/química , Colagem Dentária , Esmalte Dentário/ultraestrutura , Materiais Dentários/química , Peróxido de Hidrogênio/farmacologia , Clareadores Dentários/farmacologia , Animais , Ácido Ascórbico/química , Bovinos , Colagem Dentária/métodos , Esmalte Dentário/efeitos dos fármacos , Análise do Estresse Dentário/instrumentação , Peróxido de Hidrogênio/química , Cura Luminosa de Adesivos Dentários/métodos , Teste de Materiais , Cimentos de Resina/química , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de Superfície , Temperatura , Fatores de Tempo , Clareadores Dentários/química , Água/química
16.
J Therm Biol ; 45: 1-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25436944

RESUMO

During periods of adverse conditions small endotherms depend on a continuous supply of food and energy to maintain body temperature. Thus, rapid and reversible phenotypic modifications at different organizational levels are key for an efficient use of resources and survival. In this study, we provide a quantitative description of thermoregulatory capacities and energy-saving strategies in the Chilean marsupial Dromiciops gliroides. In particular, we evaluated the effect of thermal acclimation on basal metabolic rate (BMR), thermal conductance (C) and torpor patterns, as well as the presence of non-shivering thermogenesis (NST) as a rewarming mechanism in this marsupial. Non-significant effects of thermal acclimation were observed in BMR, C and body mass, but cold-acclimated individuals exhibited significantly longer torpor bouts. Also, minimum body temperature during torpor, inter-bout body temperature and arousal rewarming rate were lower in cold-acclimated animals. Furthermore, we found that D. gliroides did not display NST in response to Norepinephrine. Hence, despite the high regulation of torpor of other species, D. gliroides shows low flexibility in the ability to adjust energy expenditure and insulation properties, and (as in other marsupials) NST do not seems to be important as thermoregulatory mechanism.


Assuntos
Marsupiais/fisiologia , Termogênese/fisiologia , Torpor , Aclimatação , Animais , Metabolismo Basal , Peso Corporal , Norepinefrina/farmacologia , Termogênese/efeitos dos fármacos
17.
Rev. colomb. biotecnol ; 16(2): 45-56, jul.-dic. 2014. graf, tab
Artigo em Espanhol | LILACS | ID: lil-731730

RESUMO

El nitrógeno es un elemento requerido en grandes cantidades por los cultivos, sin embargo, en el suelo es uno de los elementos más limitantes ya que se encuentra en formas poco disponibles para las plantas y debe ser incorporado a través de la fertilización química o por medio de la fijación biológica llevada a cabo por microorganismos. Las bacterias simbióticas fijadoras de nitrógeno han sido ampliamente utilizadas para la elaboración de inoculantes, constituyéndose en una alternativa viable para mejorar el rendimiento de los cultivos a través de un mejor suministro de este elemento. Estos inoculantes para que puedan ser comercializados deben cumplir con ciertos requisitos de calidad que garanticen el buen funcionamiento del producto. En este estudio se evalúo la viabilidad de las cepas ICA L9 e ICA J96 en inoculantes almacenados a temperaturas de 4±2, 18±3 y 28±2 °C durante 180 días y la actividad biológica en plantas de arveja y soya. Las cepas utilizadas pertenecen al Banco de Germoplasma de Microorganismos de Corpoica; para los ensayos biológicos se emplearon semillas de arveja variedad "Santa Isabel" y soya variedad "Corpoica Superior 6". Al evaluar la viabilidad de los inoculantes almacenados a 4±2 °C, 18±3 °C y 28±2 °C, se evidenció que la temperatura no afectó la supervivencia y la concentración de rizobios después de 180 días de almacenamiento permitiendo observar un número de unidades formadoras de colonias por gramo superior a 108, valor que garantiza la calidad del inoculante. En cuanto a la actividad biológica, se observó que las cepas inoculadas fueron infectivas y efectivas para la fijación biológica del nitrógeno, compa­rado con los testigos absolutos.


Nitrogen is an element required in large amounts by most crops, however, in soil is one of the most limiting and located in ways not available to the plant and must be incorporated through chemical fertilization or by biological fixation conducted by microorganisms. Fixing symbiotic bacteria nitrogen has been widely used for the production of inoculants, becoming a viable alternative to improve crop yields through a better supply of this element. These inoculants to be marketed must meet certain requirements quality to ensure the smooth operation of the product. This study assessed the viability of the strains ICA L9 and ICA J96 inoculants stored at temperatures 4±2, 18±3 y 28±2°C for 180 days and the biological activity in pea and soybean plants. The strains used belong to the collection of work Germplasm Bank CORPOICA Microorganisms; for biological assays were used pea seeds variety "Santa Isabel" and soybean variety "Superior Corpoica 6". In assessing the viability of inoculants stored at 4±2°C, 18±3°C y 28±2°C, evidenced that the temperature did not affect the survival and the concentration of rhizobia after 180 days of storage allowing to observe a number of colony forming units per gram than 10s, value that guarantees the quality of the inoculant. Concerning the biological activity, it was observed that the strains were inoculated infective and effective biological nitrogen fixation, absolute compared to controls.

18.
Artigo em Inglês | MEDLINE | ID: mdl-25047800

RESUMO

Many mammals hibernate, which is a profound lethargic state of several weeks or months during winter, that represents a transitory episode of hetherothermy. As with other cases of dormancy, the main benefit of hibernation seems to be energy saving. However, the depth and duration of torpor can be experimentally modified by the composition of food, especially by fattyacid composition. In eutherians, diets rich in unsaturated fatty acids (i.e., fatty acids with at least one double bond) lengthen torpor, reduce metabolism and permit hibernation at lower temperatures. Here we studied whether diets varying in fatty acid composition have an effect on the physiology of hibernation in a South American marsupial, Dromiciops gliroides. We designed a factorial experiment where thermal acclimation (two levels: natural versus constant temperature) was combined with diet acclimation: saturated (i.e., diets with high concentration of saturated fatty acids) versus unsaturated (i.e., diets with high concentration of unsaturated fatty acids). We measured energy metabolism in active and torpid individuals, as well as torpor duration, and a suite of 12 blood biochemical parameters. After a cafeteria test, we found that D. gliroides did not show any preference for a given diet. Also, we did not find effects of diet on body temperature during torpor, or its duration. However, saturated diets, combined with high temperatures provoked a disproportionate increase in fat utilization, leading to body mass reduction. Those animals were more active, and metabolized more fats than those fed with a high proportion of unsaturated fatty acids (="unsaturated diets"). These results contrast with previous studies, which showed a significant effect of fatty acid composition of diets on food preferences and torpor patterns in mammals.


Assuntos
Gorduras Insaturadas na Dieta/metabolismo , Ácidos Graxos Insaturados/metabolismo , Hibernação/fisiologia , Marsupiais/metabolismo , Marsupiais/fisiologia , Animais , Índice de Massa Corporal , Metabolismo Energético/fisiologia , Estações do Ano , Temperatura , Torpor/fisiologia
19.
Sci Total Environ ; 494-495: 97-103, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25038428

RESUMO

Nicotine, a highly toxic alkaloid, has been detected in effluents, surface and groundwater and even bottled mineral water. The present work studied the photocatalytic degradation of nicotine in aqueous solution, under ultraviolet irradiation. The experiments were carried out using commercial (ZnO, TiO2) and non-conventional catalysts, which were prepared from industrial and laboratory waste. Two experimental designs (CCD) were performed for both commercial catalysts, and initial nicotine concentration, catalyst concentration and initial solution pH effects were studied. Then, the synthesized catalysts were tested under the optimal conditions which were found through CCDs. Using commercial catalysts, about 98% of the alkaloid was degraded by ZnO, and 88% by TiO2, in 1h. Among the non-conventional catalysts, the highest photocatalytic degradation (44%) was achieved using the catalyst prepared from a petrochemical industry residue.


Assuntos
Nicotina/química , Processos Fotoquímicos , Titânio/química , Poluentes Químicos da Água/química , Óxido de Zinco/química , Raios Ultravioleta
20.
Artigo em Inglês | MEDLINE | ID: mdl-23850720

RESUMO

Seasonal torpor or hibernation is a phenomenon characterized by a physiological transition to dormancy (torpor) during challenging periods in terms of energy availability or metabolic load. Extensive physiological reprogramming and changes in gene-expression, immune function, oxygen transport and intermediate metabolism, occur during eutherian hibernation. Here we studied the seasonality of blood parameters, and during daily torpor, in a South American marsupial (Dromiciops gliroides). Seasonal trends in blood parameters showed an increase in hematological parameters during winter, and increases in total proteins, albumin and globulin during autumn. In contrast, torpor induced a drastic drop during most blood parameters. PCV dropped significantly 60%, as well as RBC (58%), hemoglobin concentration (58%), WBC (79%), including neutrophils (51%), eosinophils (84%) and lymphocytes (82%). Biochemical parameters also showed reductions: triglycerides (81%), proteins (32%), albumin (24%), globulins (38%), albumin (24%), creatinine (48%) and glucose (42%). Our results confirm some patterns observed in hibernating eutherians, such as leukopenia, probably caused by sequestration of white blood cells in organs. However, red blood cells and hemoglobin concentration also were reduced, which is to the best of our knowledge has not been reported for marsupials. The observed reduction in biochemical parameters suggests that marsupials, as in eutherians, change from carbohydrate-based to lipid-based metabolism during hibernation. However, the absence of increases in beta-hydroxybutyrate is puzzling. Finally, we found an increase (although non-significant after statistical correction for multiple comparisons) of creatine kinase which together with an increase in neutrophil/lymphocyte ratio could be indicative of muscle lysis and inflammation. These results indicate profound changes in standard physiological processes during torpor.


Assuntos
Marsupiais/fisiologia , Torpor , Animais , Contagem de Células Sanguíneas , Glicemia , Proteínas Sanguíneas/metabolismo , Lipídeos/sangue , Estações do Ano
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