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1.
Eur J Prosthodont Restor Dent ; 32(1): 83-90, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-37814894

RESUMO

INTRODUCTION: The degree of conversion (DC) of resin cements can be affected by ceramics, and by the type of resin cement. The purpose was to evaluate the influence of thickness and translucencies of lithium disilicate ceramic on the DC of resin cements: two light-cure (Variolink LC; NX3 LC) and one dual-cure (NX3 Dual). METHODS: IPS e.max Press ceramic (A2) discs were prepared in 4 thicknesses (0.3, 0.5, 1.0, and 1.5 mm) and in 3 translucencies: HT (high translucency), LT (low translucency), and MO (medium opacity). Subsequently, 234 samples of resin cement (5 x 1 mm) were light-cured through those ceramic discs. The DC was assessed by Fourier Transform Infrared Spectroscopy (FTIR). RESULTS: Ceramic thicknesses decreased DC of NX3 Dual through HT-1.0 and HT 1.5 (p=0.005). Between translucencies, only MO-0.3 affected Variolink LC DC (p=0.018). There was difference among light- and dual-cured resin cements (p=0.001). CONCLUSION: Increasing thickness and opacity lead to a decrease in the DC of all resin cements, with a significantly lower DC value in NX3 Dual (HT-1.0; HT-1.5), and in Variolink LC (MO- 0.3). Light- and dual-cured resin cements were different among each other. NX3 Dual achieved a significantly lower value than its counterpart NX3 LC.


Assuntos
Porcelana Dentária , Cimentos de Resina , Cimentos de Resina/química , Teste de Materiais , Porcelana Dentária/química , Cerâmica/química , Espectroscopia de Infravermelho com Transformada de Fourier
2.
Ann Oncol ; 31(8): 1011-1020, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32387455

RESUMO

BACKGROUND: Gastroesophageal adenocarcinomas (GEAs) are heterogeneous cancers where immune checkpoint inhibitors have robust efficacy in heavily inflamed microsatellite instability (MSI) or Epstein-Barr virus (EBV)-positive subtypes. Immune checkpoint inhibitor responses are markedly lower in diffuse/genome stable (GS) and chromosomal instable (CIN) GEAs. In contrast to EBV and MSI subtypes, the tumor microenvironment of CIN and GS GEAs have not been fully characterized to date, which limits our ability to improve immunotherapeutic strategies. PATIENTS AND METHODS: Here we aimed to identify tumor-immune cell association across GEA subclasses using data from The Cancer Genome Atlas (N = 453 GEAs) and archival GEA resection specimen (N = 71). The Cancer Genome Atlas RNAseq data were used for computational inferences of immune cell subsets, which were correlated to tumor characteristics within and between subtypes. Archival tissues were used for more spatial immune characterization spanning immunohistochemistry and mRNA expression analyses. RESULTS: Our results confirmed substantial heterogeneity in the tumor microenvironment between distinct subtypes. While MSI-high and EBV+ GEAs harbored most intense T cell infiltrates, the GS group showed enrichment of CD4+ T cells, macrophages and B cells and, in ∼50% of cases, evidence for tertiary lymphoid structures. In contrast, CIN cancers possessed CD8+ T cells predominantly at the invasive margin while tumor-associated macrophages showed tumor infiltrating capacity. Relatively T cell-rich 'hot' CIN GEAs were often from Western patients, while immunological 'cold' CIN GEAs showed enrichment of MYC and cell cycle pathways, including amplification of CCNE1. CONCLUSIONS: These results reveal the diversity of immune phenotypes of GEA. Half of GS gastric cancers have tertiary lymphoid structures and are therefore promising candidates for immunotherapy. The majority of CIN GEAs, however, exhibit T cell exclusion and infiltrating macrophages. Associations of immune-poor CIN GEAs with MYC activity and CCNE1 amplification may enable new studies to determine precise mechanisms of immune evasion, ultimately inspiring new therapeutic modalities.


Assuntos
Adenocarcinoma , Neoplasias Gástricas , Adenocarcinoma/genética , Humanos , Imuno-Histoquímica , Instabilidade de Microssatélites , Neoplasias Gástricas/genética , Microambiente Tumoral/genética
3.
Lupus ; 24(11): 1191-7, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25926056

RESUMO

OBJECTIVES: To evaluate the expression of Th1, Th2, and Th17 cytokines in patients with systemic lupus erythematosus (SLE), and verify the association between serum cytokine levels and vitamin D concentration. METHODS: The sample consisted of 172 patients with SLE. 25-Hydroxyvitamin D (25(OH)D) levels were measured by chemiluminescence and 25(OH)D levels <20 ng/mL were considered to reflect vitamin D deficiency. Serum cytokine levels were measured in once-thawed samples, using a Th1/Th2/Th17 CBA (cytometric beads array) kit. RESULTS: One hundred and sixty-one (93.6%) patients were women and 128 (74.4%) were of European descent. Mean patient age was 40.5 ± 13.8 years, and mean age at diagnosis was 31.5 ± 13.4 years. At the time of study entry, patients had a median (IQR) SLEDAI of 2 (1-4) and SLICC of 0 (0-1). Mean 25(OH)D concentration was 25.4 ± 11.04 ng/mL. Fifty-nine (34.3%) patients had a vitamin D deficiency. No statistically significant associations were identified between cytokine and vitamin D levels. The most significant finding was a positive correlation between INF-α levels and SLEDAI (r(s) = 0.22, p = 0.04). CONCLUSION: Although vitamin D deficiencies are highly prevalent in patients with SLE, vitamin D levels were not significantly associated with patient cytokine profiles. The positive correlation between IFN-α levels and SLEDAI showed in this study corroborates other findings in the literature. The present results did not replicate those of in vitro studies of the effect of vitamin D levels on cytokine profiles. Placebo-controlled intervention trials of the effect of vitamin D on cytokine profiles are still required before any definitive conclusions can be drawn regarding the association between these variables.


Assuntos
Citocinas/sangue , Lúpus Eritematoso Sistêmico/sangue , Deficiência de Vitamina D/sangue , Vitamina D/análogos & derivados , Adulto , Estudos Transversais , Citocinas/metabolismo , Feminino , Citometria de Fluxo/métodos , Humanos , Interferon-alfa/sangue , Lúpus Eritematoso Sistêmico/metabolismo , Masculino , Pessoa de Meia-Idade , Prevalência , Índice de Gravidade de Doença , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia , Vitamina D/sangue , Deficiência de Vitamina D/diagnóstico , Deficiência de Vitamina D/metabolismo
4.
J Sports Med Phys Fitness ; 54(4): 403-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25034544

RESUMO

BACKGROUND: The aim of this study was to analyze the relationship between the isokinetic shoulder strength of the athletes and their performance on strength field tests. Data on the balance and functional strength ratios of the internal and external rotator muscles of shoulders of handball players was also investigated. METHODS: Twenty-seven female athletes (23±3.4 years, 71±10.6 kg and 173.3±7.1 cm) underwent an isokinetic assessment of the strength of the shoulder rotator muscles. Athletes also performed the following strength field tests: bench press test, lying bench barbell row test, handgrip test, and medicine ball throwing. RESULTS: The bench press test results and the lying bench barbell row test results were significantly correlated with the concentric internal and external rotator peak torques at 1.05 rad.s-1 and 5.23 rad.s-1, with total work at 1.05 rad.s-1 and with average power at 5.23 rad.s-1 (r=0.51 to 0.81). CONCLUSION: We suggested the use of field test to infer about internal and external rotator muscular strength, but not to infer about isokinetic muscular strength ratios. These findings could be useful to coaches and trainers.


Assuntos
Força Muscular/fisiologia , Manguito Rotador/fisiologia , Esportes/fisiologia , Adulto , Teste de Esforço/métodos , Feminino , Força da Mão , Humanos , Levantamento de Peso , Adulto Jovem
5.
Braz J Med Biol Res ; 57: e13234, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38716980

RESUMO

Patients undergoing chemotherapy with cisplatin commonly present gastrointestinal effects such as constipation and gastric emptying (GE) delay. Both the purinergic system and physical exercise modulate the gastrointestinal (GI) tract. In the current study, we investigated the role of ATP, physical exercise, and P2X7 receptor blocking on GE delay induced by cisplatin in rats. Male rats were divided into the following groups: control (C), cisplatin (Cis), exercise (Ex), Brilliant Blue G (BBG), ATP, Cis+Ex, Cis+ATP, Cis+BBG, Cis+Ex+BBG, Cis+Ex+BBG+ATP, and Cis+ATP+BBG. GE delay was induced by treatment with 1 mg/kg cisplatin (1 time/week for 5 weeks, ip). The moderate physical exercise was swimming (1 h/day, 5 days/week for 5 weeks). At the end of the treatment or exercise and 30 min before the GE assessment, some groups received BBG (50 mg/kg, sc) or ATP (2 mg/kg, sc). Then, GE was assessed after a 10-min postprandial period. Chronic use of Cis decreased GE delay (P<0.05) compared to the control group. Both exercise and ATP prevented (P<0.05) GE delay compared to Cis. The pretreatment with BBG significantly inhibited (P<0.05) the effect of exercise and ATP. On the other hand, the association between exercise and ATP reversed (P<0.05) the effect of the BBG and prevented GE delay. Therefore, we suggest that both exercise and treatment with ATP activate P2X7 receptors and prevent GE delay induced by cisplatin in rats.


Assuntos
Trifosfato de Adenosina , Antineoplásicos , Cisplatino , Esvaziamento Gástrico , Condicionamento Físico Animal , Ratos Wistar , Receptores Purinérgicos P2X7 , Animais , Cisplatino/farmacologia , Masculino , Trifosfato de Adenosina/metabolismo , Esvaziamento Gástrico/efeitos dos fármacos , Esvaziamento Gástrico/fisiologia , Receptores Purinérgicos P2X7/metabolismo , Condicionamento Físico Animal/fisiologia , Antineoplásicos/farmacologia , Ratos , Antagonistas do Receptor Purinérgico P2X/farmacologia
6.
Biochim Biophys Acta Gen Subj ; 1865(10): 129963, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34246719

RESUMO

BACKGROUND: Intrinsic resistance of cancer cells is a major concern for the success of chemotherapy, and this undesirable feature stimulates further research into the design of new compounds and/or alternative multiple drug chemotherapy protocols. METHODS: In this study, we investigated the antitumoral potential of the coordination compounds [Cu(HPClNOL)Cl]Cl (1), [Fe(HPClNOL)Cl2]NO3(2) and [Mn(HPClNOL)Cl2] (3). Using the human, MCF-7 and A549, and the murine melanoma, B16-F10, cell lines, we determined the cytotoxicity, DCFH oxidation, disruption of mitochondrial membrane potential (ΔΨm), Sub-G1 and TUNEL positive cells, and caspase 8 and 9 activities. Fractional inhibitory concentration (FIC) and xenograft models were also assessed to evaluate the efficacy of antitumoral potential. RESULTS: We observed that only complex 1 was cytotoxic. The treatment of cancer cells with complex 1 triggered ROS generation and promoted the disruption of ΔΨm. Complex 1 increased the number of Sub-G1 and TUNEL positive cells, and the measurement of caspase 8 and 9 activity confirmed that apoptosis was triggered by the intrinsic pathway. FIC demonstrated that the combination of complex 1 with cisplatin was additive for the A549 cells whilst it was synergic for MCF-7 and B16-F10. Treatment with complex 1, either alone or combined with cisplatin, reduced tumor growth on xenograft models. CONCLUSIONS: The present study brings new clues regarding the mechanism of action of [Cu(HPClNOL)Cl]Cl, either alone or in combination with cisplatin. GENERAL SIGNIFICANCE: These results indicate that complex 1, administered either singly or in combination with current drugs, has real potential for use in cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Complexos de Coordenação/farmacologia , Cobre/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/química , Complexos de Coordenação/química , Cobre/química , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Células Tumorais Cultivadas
7.
J Nutr Health Aging ; 25(7): 889-894, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34409967

RESUMO

OBJECTIVES: Significant weight loss and/or loss of appetite is a criterion of a depressive episode. While malnutrition is associated with many adverse health outcomes, the impact of malnutrition in late-life depression has hardly been examined. The present study aims to (1) evaluate the prevalence of malnutrition in depressed older inpatients, and (2) whether and which indices of malnutrition predict adverse health outcomes in late-life depression. DESIGN: A prospective study at 6 months follow-up. SETTING: A University-based psychiatric hospital. PARTICIPANTS: 105 older adults (psychiatric inpatients suffering from unipolar MDD). MEASUREMENTS: Participants were evaluated according the Mini Nutritional Assessment (MNA) and anthropometric measures to assess their nutritional status. Multiple regression analyses were used to evaluate the association between the MNA score as well as anthropometric measures with either falls or rehospitalization for any reason. RESULTS: Based on the MNA score, 78 (74.3%) patients were at risk of malnutrition and 13 (12.4%) actually presented malnutrition. Malnutrition was associated with a higher age, frailty, lower body mass index, and smaller calf circumference. During follow-up, 21 (20%) patients fell, 27 (25.7%) were rehospitalized, and 3 died (2.9%). The MNA score was associated with adverse health outcomes, but a low calf circumference predicted falling (OR 4.93 [95% CI: 1.42-17.2], p=.012) and a higher calf circumference rehospitalization (OR 1.17 [95% CI: 1.01-1.35], p=.032). CONCLUSION: Malnutrition is prevalent in older depressed inpatients. In contrast to subjective proxies for malnutrition, which are common in depression, only objective measures of malnutrition predict adverse health outcomes such as falls and rehospitalization.


Assuntos
Transtorno Depressivo Maior , Avaliação Geriátrica , Desnutrição , Avaliação Nutricional , Estado Nutricional , Idoso , Idoso de 80 Anos ou mais , Anorexia/etiologia , Transtorno Depressivo Maior/complicações , Transtorno Depressivo Maior/psicologia , Feminino , Humanos , Pacientes Internados , Masculino , Desnutrição/diagnóstico , Desnutrição/etiologia , Desnutrição/psicologia , Pessoa de Meia-Idade , Estudos Prospectivos , Redução de Peso
8.
Scand J Med Sci Sports ; 20(4): 638-43, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19793219

RESUMO

Participation in sports for individuals with disabilities continues to gain popularity. In order to provide fair and equitable competition among persons with different disabilities and functional capacity, a separate functional classification system has been devised for each sport. The aims of the present study were to evaluate aerobic and anaerobic performance of wheelchair basketball athletes and verify a correlation with the International Wheelchair Basketball Federation functional classification system. For this, 17 highly trained male Brazilian basketball wheelchair athletes (25.4+/-4.4 years) from the national team who had taken part in the Athens 2004 Paralympic Games were assessed. These athletes were submitted to cardiopulmonary exercise testing and Wingate-like 30-s sprint test using upper limbs. The present study demonstrated that the functional classification score correlated with relative (r=0.90; P<0.0001) and absolute peak power (r=0.50; P=0.0353) and absolute mean power (r=0.93; P<0.0001) obtained from the Wingate-like 30-s sprint test and also correlated with absolute O(2) peak (r=0.68; P=0.0026) and O(2) at ventilatory threshold (r=0.71; P=0.0014), measured on cardiopulmonary exercise testing. Therefore, our findings support the functional classification created to classify athletes' functional capability on the court, which also correlated with aerobic and anaerobic performance parameters of the elite wheelchair basketball players.


Assuntos
Limiar Anaeróbio/fisiologia , Basquetebol/fisiologia , Pessoas com Deficiência/classificação , Exercício Físico/fisiologia , Cadeiras de Rodas , Adulto , Desempenho Atlético/fisiologia , Brasil , Avaliação da Deficiência , Humanos , Masculino , Adulto Jovem
9.
Forensic Sci Int ; 306: 110071, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31785510

RESUMO

The presence of Ethyl glucuronide (EtG) in hair provides a strong indication of ethanol consumption and its investigation is of interest in both clinical and forensic contexts because of the wide window of detection. However, due to the possibility of false negative results in cases of small ethanol intake or excessive hair washing, the combined measurement of ethyl palmitate (EtP) with EtG could be useful. In this study, a sensitive UHPLC-MS/MS procedure for the measurement of EtG in hair was developed and validated, using optimized sample preparation and chromatographic separation. Milled hair was extracted with water for 24 h at room temperature, followed by clean-up of the extract by ion-exchange solid phase extraction (SPE). Extraction was highly efficient, with yield of 96.93-101.06%. Chromatographic separation was performed with a Fluoro-Phenyl stationary phase. The assay was linear from 4 to 500pgmg-1, with accuracy in the range of 100.30-106.16%. Matrix effects (-0.87 to 5.89%) were adequately compensated by the use of deuterated EtG as internal standard. EtG was measured in hair samples of 46 volunteers, and results were compared with hair concentrations of ethyl palmitate (EtP) and the score in the AUDITC questionnaire. EtG hair concentrations were significantly correlated to the AUDIT-C classification (rs=0.365, p<0.05), but not to EtP hair levels. The diagnostic performance of EtG hair concentrations to identify excessive or moderate ethanol use was similar to the capability of AUDIT-C to identify severe and high health risk (Kappa, p=0.013). The developed assay is suitable for clinical use, providing a useful tool to evaluate chronic ethanol consumption.


Assuntos
Consumo de Bebidas Alcoólicas , Alcoolismo/diagnóstico , Glucuronatos/análise , Cabelo/química , Detecção do Abuso de Substâncias/métodos , Adulto , Biomarcadores/análise , Cromatografia Líquida , Feminino , Toxicologia Forense/métodos , Humanos , Masculino , Ácidos Palmíticos/análise , Extração em Fase Sólida , Espectrometria de Massas em Tandem
10.
J Anal Toxicol ; 44(4): 402-409, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-31909801

RESUMO

The use of hair as a matrix for the evaluation of chronic ethanol drinking behavior presents the advantage of a longer window of detection and higher specificity when compared to classical biochemical markers. The most recent recommendations the Society of Hair Testing (SOHT) indicate that ethyl palmitate (EtP) hair levels can be used to estimate the ethanol drinking behavior, alternatively to the combined measurement of four main fatty acid ethyl esters. In this study, solid-phase microextraction (SPME) conditions for the extraction of EtP from hair were optimized using response surface analysis, after a Box-Behnken experiment. Analyses were performed by GC-MS. The optimized HS-SPME conditions, using a PDMS-DVB (65 µm) fiber, were pre-adsorption time of 6 min, extraction time of 60 min and incubation temperature of 94°C. The linear range was 0.05 to 3 ng mg-1, with accuracy within 95.15-109.91%. Between-assay and within-assay precision were 8.58-12.53 and 6.12-6.82%, respectively. The extraction yield was 61.3-71.9%. The assay was applied to hair specimens obtained from 46 volunteers, all presenting EtP levels within the linear range of the assay. Using a statistically designed experiment, a sensitive SPME-GC-MS assay for the measurement of EtP in hair was developed and validated, requiring only 20 mg of hair.


Assuntos
Cabelo/química , Ácidos Palmíticos/análise , Microextração em Fase Sólida/métodos , Ésteres , Ácidos Graxos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Sensibilidade e Especificidade
11.
Science ; 269(5225): 832-6, 1995 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-7638600

RESUMO

The Escherichia coli chaperonin GroEL and its regulator GroES are thought to mediate adenosine triphosphate-dependent protein folding as an asymmetrical complex, with substrate protein bound within the GroEL cylinder. In contrast, a symmetrical complex formed between one GroEL and two GroES oligomers, with substrate protein binding to the outer surface of GroEL, was recently proposed to be the functional chaperonin unit. Electron microscopic and biochemical analyses have now shown that unphysiologically high magnesium concentrations and increased pH are required to assemble symmetrical complexes, the formation of which precludes the association of unfolded polypeptide. Thus, the functional significance of GroEL:(GroES)2 particles remains to be demonstrated.


Assuntos
Chaperonina 10/metabolismo , Chaperonina 60/metabolismo , Trifosfato de Adenosina/farmacologia , Adenilil Imidodifosfato/farmacologia , Chaperonina 10/química , Chaperonina 10/ultraestrutura , Chaperonina 60/química , Chaperonina 60/ultraestrutura , Concentração de Íons de Hidrogênio , Magnésio/farmacologia , Microscopia Eletrônica de Transmissão e Varredura , Dobramento de Proteína
13.
Trends Biochem Sci ; 16(2): 53-7, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1858133

RESUMO

Calcium binding to proteins containing the 'EF-hand' structural motif regulates a variety of biochemical processes including muscle contraction. Techniques such as protein crystallography, site-directed mutagenesis and domain transplantation experiments are being used to unravel the conformational changes induced by calcium binding.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Cálcio/metabolismo , Proteínas Musculares/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Ligação ao Cálcio/química , Metais/química , Metais/metabolismo , Dados de Sequência Molecular , Contração Muscular , Proteínas Musculares/química , Conformação Proteica
14.
Braz J Med Biol Res ; 52(5): e7798, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31116311

RESUMO

Himatanthus drasticus (Mart.) Plumel belongs to the Apocynaceae family and the latex from its trunk bark (Hd) is known as "janaguba milk". This latex is widely used in Northeast Brazil, mainly in the Cariri region, for its gastroprotective, anti-inflammatory, and antitumor properties. The objective of this study was to investigate a triterpene-rich fraction (FJNB) from H. drasticus latex on acute models of nociception and inflammation and to clarify its mechanisms of action. Wistar rats or Swiss mice were subjected to the carrageenan-induced paw edema test or the formalin test, respectively, after the acute oral treatment with FJNB. The inflamed paws from the carrageenan-induced paw edema and formalin tests were processed for histological and immunohistochemical assays, respectively. The results were analyzed by ANOVA and considered significant at P<0.05. FJNB (10 mg/kg) decreased the paw edema by 25% at the 3rd h after the carrageenan injection. Indomethacin, used as reference, inhibited the paw edema by 59% at the same time-point. In the formalin test, FJNB inhibited the 1st phase by 27, 49, and 52% and the 2nd phase by 37, 50, and 67%, at the doses of 1, 5, and 10 mg/kg, respectively. In addition, FJNB significantly inhibited the expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and the inflammatory cytokine tumor necrosis factor (TNF)-alpha. The histone deacetylase (HDAC) expression and the transcription factor nuclear factor kappa (NF-kB) were also inhibited at the same doses. In conclusion, the FJNB inhibitory actions on iNOS, COX-2, TNF-α, HDAC, and NF-kB could be involved with the drug anti-inflammatory activity.


Assuntos
Analgésicos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Apocynaceae/química , Edema/tratamento farmacológico , Inflamação/tratamento farmacológico , Triterpenos/uso terapêutico , Animais , Biomarcadores/sangue , Modelos Animais de Doenças , Imuno-Histoquímica , Masculino , Camundongos , Ratos , Ratos Wistar , Triterpenos/isolamento & purificação
15.
Braz. j. med. biol. res ; 57: e13234, fev.2024. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1557319

RESUMO

Patients undergoing chemotherapy with cisplatin commonly present gastrointestinal effects such as constipation and gastric emptying (GE) delay. Both the purinergic system and physical exercise modulate the gastrointestinal (GI) tract. In the current study, we investigated the role of ATP, physical exercise, and P2X7 receptor blocking on GE delay induced by cisplatin in rats. Male rats were divided into the following groups: control (C), cisplatin (Cis), exercise (Ex), Brilliant Blue G (BBG), ATP, Cis+Ex, Cis+ATP, Cis+BBG, Cis+Ex+BBG, Cis+Ex+BBG+ATP, and Cis+ATP+BBG. GE delay was induced by treatment with 1 mg/kg cisplatin (1 time/week for 5 weeks, ip). The moderate physical exercise was swimming (1 h/day, 5 days/week for 5 weeks). At the end of the treatment or exercise and 30 min before the GE assessment, some groups received BBG (50 mg/kg, sc) or ATP (2 mg/kg, sc). Then, GE was assessed after a 10-min postprandial period. Chronic use of Cis decreased GE delay (P<0.05) compared to the control group. Both exercise and ATP prevented (P<0.05) GE delay compared to Cis. The pretreatment with BBG significantly inhibited (P<0.05) the effect of exercise and ATP. On the other hand, the association between exercise and ATP reversed (P<0.05) the effect of the BBG and prevented GE delay. Therefore, we suggest that both exercise and treatment with ATP activate P2X7 receptors and prevent GE delay induced by cisplatin in rats.

16.
Sci Rep ; 8(1): 9578, 2018 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-29934550

RESUMO

The Frasnian-Famennian boundary records one of the most catastrophic mass extinctions of the Phanerozoic Eon. Several possible causes for this extinction have been suggested, including extra-terrestrial impacts and large-scale volcanism. However, linking the extinction with these potential causes is hindered by the lack of precise dating of either the extinction or volcanic/impact events. In this study, a bentonite layer in uppermost-Frasnian sediments from Steinbruch Schmidt (Germany) is re-analysed using CA-ID-TIMS U-Pb zircon geochronology in order to constrain the date of the Frasnian-Famennian extinction. A new age of 372.36 ± 0.053 Ma is determined for this bentonite, confirming a date no older than 372.4 Ma for the Frasnian-Famennian boundary, which can be further constrained to 371.93-371.78 Ma using a pre-existing Late Devonian age model. This age is consistent with previous dates, but is significantly more precise. When compared with published ages of the Siljan impact crater and basalts produced by large-scale volcanism, there is no apparent correlation between the extinction and either phenomenon, not clearly supporting them as a direct cause for the Frasnian-Famennian event. This result highlights an urgent need for further Late Devonian geochronological and chemostratigraphic work to better understand the cause(s) of this extinction.

17.
Plant Dis ; 91(5): 631, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-30780712

RESUMO

Huanglongbing (HLB), also known as greening, is one of the most important diseases of citrus worldwide. The causal agent is a gram-negative bacterium known to inhabit the phloem of infected plants. Three different candidate species infect citrus: 'Candidatus Liberibacter africanus' found in the African continent; 'Ca. L. asiaticus' found in Asia, Brazil, and the United States; and 'Ca. L. americanus' found in Brazil. (1). Tobacco is an easily transformable plant species that can be used as an experimental host system to quickly screen for candidate genes useful to control plant pathogens. However, no evidence exists on the ability of this plant species to sustain populations of 'Ca. L. americanus'. With the purpose of transmitting 'Ca. L. americanus' from citrus to tobacco, fragments of healthy stems of Cuscuta spp. (dodder) were used to connect an HLB-infected sweet orange plant to each of 10 healthy plants of Nicotiana tabacum L. cv. Xanthi and allowed to remain connected for 30, 45, and 50 days. Three different HLB-infected orange plants and 30 tobacco plants were used in three independent experiments. Most HLB-exposed Xanthi plants exhibited chlorotic leaves after 50 days of exposure probably because of the parasitic effect of dodder; however, an average of 6, 1, and 3 Xanthi plants exhibited a unique blotchy mottle symptom after 30, 45, and 50 days of exposure, respectively. Symptomatic and asymptomatic leaves were collected and analyzed by PCR. The results consistently confirmed the presence of 'Ca. L. americanus' only in symptomatic leaves. Sequencing of the PCR product and comparison to the NCBI database also confirmed the identity of the pathogen as 'Ca. L. americanus'. Electron microscopy analysis of four symptomatic leaves indicated the presence of bacterium-like bodies with round to elongated bacilliform shapes and surrounded by two membranes. These bodies resembled those already described in HLB-infected citrus in Brazil (1). The evidence presented above confirms the successful transmission of 'Ca. L. americanus' from citrus to Xanthi using the parasitic plant Cuscuta spp. Reference: (1) F. A. O. Tanaka et al. Fitopatol. Bras. 31:99, 2006.

18.
Br J Sports Med ; 40(11): 918-22, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16950883

RESUMO

OBJECTIVE: To determine the prevalence of coronary risk factors in Paralympic athletes and evaluate their risk of coronary events. METHOD: An observational prospective cross sectional study of 79 consecutive Brazilian Paralympic athletes (mean (SD) age 27.8 (6.7) years (median 26 years)). There were 56 men and 23 women, 67 with physical and 12 with visual disabilities. The occurrence of systemic hypertension, hypercholesterolaemia, diabetes mellitus, smoking, familial antecedents, obesity, and hypertriglyceridaemia was investigated. The risk of coronary events was calculated using the American Heart Association Coronary risk handbook, and also the 10 year probability of a coronary event using the Framingham risk score. RESULTS: The prevalence of risk factors was: systemic hypertension, 11%; familial antecedents, 10%; smoking, 9%; hypertriglyceridaemia, 6%; hypercholesterolaemia, 1.3%; obesity, 4%; diabetes, 0%. They occurred in 51% of the Paralympic athletes: one factor (41%), two factors (4%), and three factors (6%). The risk of coronary events was absent in 80%, slight in 17%, and moderate in 3%. This could only be evaluated in 81% of the athletes, as 8% had amputations, 9% were young, and 2% had unknown familial antecedents. The Framingham risk score ranged from -14 to +6, predicting a 10 year probability of a coronary event of 3.3 (3.8)%. CONCLUSION: This study shows a reasonably high prevalence of coronary risk factors (51%), despite a low probability of coronary events in Paralympic athletes. The lipid and blood pressure profiles were similar in ambulatory and wheelchair athletes.


Assuntos
Doença das Coronárias/etiologia , Pessoas com Deficiência , Esportes/fisiologia , Adolescente , Adulto , Pressão Sanguínea/fisiologia , Brasil/epidemiologia , Doença das Coronárias/epidemiologia , Métodos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Annu Rev Phytopathol ; 40: 169-89, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12147758

RESUMO

This review deals with a comparative analysis of seven genome sequences from plant-associated bacteria. These are the genomes of Agrobacterium tumefaciens, Mesorhizobium loti, Sinorhizobium meliloti, Xanthomonas campestris pv campestris, Xanthomonas axonopodis pv citri, Xylella fastidiosa, and Ralstonia solanacearum. Genome structure and the metabolism pathways available highlight the compromise between the genome size and lifestyle. Despite the recognized importance of the type III secretion system in controlling host compatibility, its presence is not universal in all necrogenic pathogens. Hemolysins, hemagglutinins, and some adhesins, previously reported only for mammalian pathogens, are present in most organisms discussed. Different numbers and combinations of cell wall degrading enzymes and genes to overcome the oxidative burst generally induced by the plant host are characterized in these genomes. A total of 19 genes not involved in housekeeping functions were found common to all these bacteria.


Assuntos
Bactérias/genética , Genoma Bacteriano , Doenças das Plantas/microbiologia , Plantas/microbiologia , Adaptação Fisiológica/genética , Bactérias/crescimento & desenvolvimento , Aderência Bacteriana/genética , Aderência Bacteriana/fisiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Extensões da Superfície Celular/genética , Extensões da Superfície Celular/fisiologia , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Filogenia
20.
Neuroscience ; 315: 196-205, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26704636

RESUMO

High sugar consumption is a risk factor for metabolic disturbances leading to memory impairment. Thus, rats subject to high sucrose intake (HSu) develop a metabolic syndrome and display memory deficits. We now investigated if these HSu-induced memory deficits were associated with metabolic and electrophysiological alterations in the hippocampus. Male Wistar rats were submitted for 9 weeks to a sucrose-rich diet (35% sucrose solution) and subsequently to a battery of behavioral tests; after sacrifice, their hippocampi were collected for ex vivo high-resolution magic angle spinning (HRMAS) metabolic characterization and electrophysiological extracellular recordings in slices. HSu rats displayed a decreased memory performance (object displacement and novel object recognition tasks) and helpless behavior (forced swimming test), without altered locomotion (open field). HRMAS analysis indicated a similar hippocampal metabolic profile of HSu and control rats. HSu rats also displayed no change of synaptic transmission and plasticity (long-term potentiation) in hippocampal Schaffer fibers-CA1 pyramid synapses, but had decreased amplitude of long-term depression in the temporoammonic (TA) pathway. Furthermore, HSu rats had an increased density of inhibitory adenosine A1 receptors (A1R), that translated into a greater potency of A1R in Schaffer fiber synapses, but not in the TA pathway, whereas the endogenous activation of A1R in HSu rats was preserved in the TA pathway but abolished in Schaffer fiber synapses. These results suggest that HSu triggers a hippocampal-dependent memory impairment that is not associated with altered hippocampal metabolism but is probably related to modified synaptic plasticity in hippocampal TA synapses.


Assuntos
Dieta/efeitos adversos , Sacarose Alimentar/toxicidade , Hipocampo/fisiopatologia , Transtornos da Memória/etiologia , Transtornos da Memória/fisiopatologia , Animais , Modelos Animais de Doenças , Emoções/fisiologia , Desamparo Aprendido , Locomoção/fisiologia , Potenciação de Longa Duração/fisiologia , Depressão Sináptica de Longo Prazo/fisiologia , Masculino , Atividade Motora/fisiologia , Ratos Wistar , Receptor A1 de Adenosina/metabolismo , Reconhecimento Psicológico/fisiologia , Sinapses/fisiologia , Transmissão Sináptica/fisiologia
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