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1.
Semergen ; 45(2): 77-85, 2019 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-30600153

RESUMO

INTRODUCTION: To assess the effects of a visual Decalogue aid on the degree of knowledge, control perception and improvement in cardiovascular risk factors (CVRF). MATERIAL AND METHODS: A Primary care randomised non-pharmacological trial of an educational intervention with a parallel control group, and blind evaluation in type 2 diabetic patients. Both groups received an educational intervention on the management of CVRF. The intervention group also received a visual Decalogue aid that showed the level of control patients have over the modifiable CVRF. A total of 50 patients were included in each group in order to identify an improvement of 50% in the multifactorial knowledge of CVRF. All patients received a reminder telephone call at 2 months, with masked evaluation of knowledge and CVRF control perception. In a 6 months visit the level of knowledge and real control of CVRF were re-evaluated. RESULTS: The study included 51 males and 49 females, with mean age of 62.9 years, a mean disease duration of 9.2 years, and low educational level. The level of knowledge, control perception, and real control at baseline was 55%, 80.4%, and 65.9%, respectively. After 2 months the level of knowledge in the Decalogue group increased by 16.5% more than in the conventional education group (73.6% vs. 63.2%; P<.05) and the overestimated control perception improved by 34.5% (P<.001) with no differences between groups, although concordance was better in the Decalogue group. At 6 months there was an overall increase 25.6% (P<.001) in the level of knowledge, with the previous difference between groups levelling off. The final CVRF control improved overall and in the Decalogue group by 6.4% (P<.005) and 9.4% (P<.001), respectively. The SCORE risk significantly decreased overall with no differences between groups. CONCLUSIONS: The educational intervention improves the overall level of knowledge, perception and control of CVRF. The CVRF Decalogue quickly increases the level of knowledge, and decreases the false subjective risk control perception. The benefit, however, becomes equal at 6 months with ongoing education interventions.


Assuntos
Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Complicações do Diabetes/etiologia , Complicações do Diabetes/prevenção & controle , Diabetes Mellitus Tipo 2/complicações , Conhecimentos, Atitudes e Prática em Saúde , Educação de Pacientes como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Educação de Pacientes como Assunto/métodos , Estudos Prospectivos
2.
Int J Cosmet Sci ; 40(6): 575-582, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30414278

RESUMO

OBJECTIVE: Zein is known to have filmogen properties. We wanted to show if a zein film containing eugenol (eugenol as model) would retain the fragrances, slow their evaporation and therefore produce a long-lasting perception of perfume. METHODS: We added corn zein to eugenol in a hydro-alcoholic solution to form a film in vitro and at the surface of the human skin. We have studied the trapping and release of eugenol from zein film by GC/MS. Also we labelled eugenol with deuterium to image specifically its distribution in the zein film using Secondary Ion Mass Spectrometry technique (NanoSIMS 50). Finally, we applied the zein/D-eugenol formulation onto skin to image the eugenol location on and in skin by SIMS (Secondary Ion Mass Spectrometry). RESULTS: We showed that eugenol evaporation from zein film can be divided in three periods. The first period (≤2 h) corresponds to the simultaneous solvent and eugenol evaporation occurring during film formation. The second period corresponds to the continuous and slow eugenol evaporation during a few hours (about 10 h) but not to its completion. The third period (at least up to 48 h) results from the trapping of eugenol in zein film. After 24 or 48 h, trapped eugenol can be released and evaporated under mechanical deformations of the film. Moreover we showed that zein addition does not favour the eugenol penetration into viable epidermis which may cause allergenic cutaneous reaction. CONCLUSION: The zein additive is safe to use, does not impact the olfactory perception, allows a better perception of the fragrance (long-lasting effect) in a more protective way and can be used in perfume.


Assuntos
Perfumes/química , Zeína/efeitos adversos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Microscopia Eletrônica de Varredura
3.
Glia ; 66(2): 239-255, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29027701

RESUMO

Diffuse low grade gliomas (DLGG, grade II gliomas) are slowly-growing brain tumors that often progress into high grade gliomas. Most tumors have a missense mutation for IDH1 combined with 1p19q codeletion in oligodendrogliomas or ATRX/TP53 mutations in astrocytomas. The phenotype of tumoral cells, their environment and the pathways activated in these tumors are still ill-defined and are mainly based on genomics and transcriptomics analysis. Here we used freshly-resected tumors to accurately characterize the tumoral cell population and their environment. In oligodendrogliomas, cells express the transcription factors MYT1, Nkx2.2, Olig1, Olig2, Sox8, four receptors (EGFR, PDGFRα, LIFR, PTPRZ1) but not the co-receptor NG2 known to be expressed by oligodendrocyte progenitor cells. A variable fraction of cells also express the more mature oligodendrocytic markers NOGO-A and MAG. DLGG cells are also stained for the young-neuron marker doublecortin (Dcx) which is also observed in oligodendrocytic cells in nontumoral human brain. In astrocytomas, MYT1, PDGFRα, PTPRZ1 were less expressed whereas Sox9 was prominent over Sox8. The phenotype of DLGG cells is overall maintained in culture. Phospho-array screening showed the absence of EGFR and PDGFRα phosphorylation in DLGG but revealed the strong activation of p44/42 MAPK/ERK which was present in a fraction of tumoral cells but also in nontumoral cells. These results provide evidence for the existence of close relationships between the cellular phenotype and the mutations found in DLGG. The slow proliferation of these tumors may be associated with the absence of activation of PDGFRα/EGFR receptors.


Assuntos
Neoplasias Encefálicas/genética , Receptores ErbB/genética , Glioma/genética , Isocitrato Desidrogenase/genética , Mutação/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Adulto , Animais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Proteína Duplacortina , Receptores ErbB/metabolismo , Feminino , Glioma/metabolismo , Glioma/patologia , Proteína Homeobox Nkx-2.2 , Proteínas de Homeodomínio , Humanos , Isocitrato Desidrogenase/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , Gradação de Tumores/métodos , Proteínas Nucleares , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Fatores de Transcrição , Células Tumorais Cultivadas , Adulto Jovem
6.
Aliment Pharmacol Ther ; 44(5): 514-21, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27385440

RESUMO

BACKGROUND: The diagnosis of covert hepatic encephalopathy (CHE) by means of portosystemic encephalopathy syndrome (PSE) test is costly and therefore infrequently performed. AIM: To determine the ability of critical flicker frequency (CFF) alone or in combination with laboratory findings, as an initial test to pre-select which patients should undergo further testing for the diagnosis of covert hepatic encephalopathy. METHODS: This single-centre study included all patients with cirrhosis who underwent PSE and CFF in 2011. CHE was defined by abnormal PSE test. Logistic regression analysis was performed to identify predictors of CHE. ROC curves were used to identify cut-offs of these independent predictors. RESULTS: One hundred and seventeen patients were included. Seventy (60%) had CHE with a higher MELD [16 (IQR 13-21); P = 0.001] and lower CFF [38 Hz (IQR 36-41) P = 0.0011]. On multivariate analyses, CFF [OR 0.83 (95% CI 0.74-0.94)] and MELD [OR 1.13 (95% CI 1.04-1.22)] were identified as independent predictors of CHE. Sensitivity and specificity of a CFF cut-off of 43 Hz was 93.5% and 42.9%, and for a MELD cut-off of 24, it was 97.5% and 32.8% respectively. Most patients with a MELD-Score <24 and a CFF >43 Hz did not have CHE (78%) and with a MELD-Score >24 and CFF <43 Hz most patients had CHE (85%). Therefore, 27% of patients could avoid further testing with a diagnostic accuracy of 81%. CONCLUSION: The combination of MELD-score and critical flicker frequency may be used as a first diagnostic step to filter patients, in whom further covert hepatic encephalopathy testing could be avoided.


Assuntos
Fusão Flicker , Encefalopatia Hepática/diagnóstico , Encefalopatia Hepática/fisiopatologia , Cirrose Hepática/diagnóstico , Cirrose Hepática/fisiopatologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos
7.
J Viral Hepat ; 18(10): 685-91, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21914085

RESUMO

The hepatic venous pressure gradient (HVPG) is the gold standard for assessing portal pressure and correlates with the occurrence of portal hypertension (PH)-related complications. Transient elastography (TE) is a new, highly accurate noninvasive technique, which enables us to evaluate hepatic fibrosis to detect advanced fibrosis and cirrhosis. We performed a hepatic haemodynamic study and TE in 38 HIV/HCV-coinfected patients. The association between HVPG and liver stiffness was assessed by linear regression. The diagnostic value of TE was assessed by receiver operating characteristic (ROC) curves. We considered clinically significant PH as an HVPG ≥ 10 mmHg and severe PH as an HVPG ≥ 12 mmHg. A total of 38 HIV/HCV-coinfected patients were included. Twenty-eight patients (73.7%) had clinically significant PH (HVPG ≥ 10 mmHg), and 23 (60.5%) of these had severe PH (HVPG ≥ 12 mmHg). We found a statistically significant association between liver stiffness (kPa) and HVPG (r(2) = 0.46, P < 0.001, straight line equation HVPG=7.4 + 0.204*TE). The areas under the ROC curves were 0.80 [95% confidence interval (CI), 0.64-0.97] and 0.80 (95% CI, 0.66-0.94) for the prediction of HVPG ≥ 10 and ≥ 12 mmHg, respectively. Our data suggest that TE can predict the presence of clinically significant and severe PH in HIV/HCV-coinfected patients.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Infecções por HIV/complicações , Hepatite C/complicações , Hipertensão Portal/diagnóstico , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC
8.
Osteoarthritis Cartilage ; 19(1): 1-21, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21035558

RESUMO

OBJECTIVES: The aim of this first global systematic review on selected nutraceuticals was to synthesize and evaluate scientific relevant data available in the literature. Evidences that can support health, physiological or functional benefit on osteoarthritis (OA) were gathered and the level of evidence relative to each of these ingredients was highlighted. METHODOLOGY: Relevant scientific data (positive or not) regarding OA were searched for five groups of compounds (avocado/soybean unsaponifiables (ASU), n-3 polyunsaturated fatty acids, collagen hydrosylates (CHs), vitamin D, polyphenols) within preclinical (in vitro and in vivo), epidemiological, and clinical studies. The following criteria were evaluated to assess the methodology quality of each study: (1) study question; (2) study population; (3) primary endpoint; (4) study design (randomization, control, blinding, duration of follow up); (5) data analysis and interpretation. A scientific consensus was determined for all studied nutraceuticals to evaluate their efficacy in OA. RESULTS: The studied compounds demonstrated different potencies in preclinical studies. Most of them have demonstrated anti-catabolic and anti-inflammatory effects by various inhibitory activities on different mediators. Vitamin D showed a pro-catabolic effect in vitro and the polyphenol, Genistein, had only anti-inflammatory potency. The evaluation of the clinical data showed that ASU was the only one of the studied ingredients to present a good evidence of efficacy, but the efficient formulation was considered as a drug in some countries. Pycnogenol showed moderate evidence of efficacy, and vitamin D and collagen hydrolysate demonstrated a suggestive evidence of efficacy, whereas curcumin, epigallocatechin-3-gallate (EGCG) and resveratrol had only preclinical evidence of efficacy due to the lack of clinical data. The literature gathered for n-3 PUFA, nobiletin and genistein was insufficient to conclude for their efficacy in OA. CONCLUSION: Additional data are needed for most of the studied nutraceuticals. Studies of good quality are needed to draw solid conclusions regarding their efficacy but nutraceuticals could represent good alternates for OA management. Their use should be driven by any recommendations.


Assuntos
Terapia Nutricional , Osteoartrite/terapia , Colágeno/uso terapêutico , Ácidos Graxos/uso terapêutico , Flavonoides/uso terapêutico , Alimentos Orgânicos , Humanos , Fenóis/uso terapêutico , Fitosteróis/uso terapêutico , Polifenóis , Vitamina D/uso terapêutico
9.
J Phys Chem B ; 112(17): 5534-46, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-18399679

RESUMO

Localizing two or more components of assemblies in biological systems requires both continued development of fluorescence techniques and invention of entirely new techniques. Candidates for the latter include dynamic secondary ion mass spectrometry (D-SIMS). The latest generation of D-SIMS, the Cameca NanoSIMS 50, permits the localization of specific, isotopically labeled molecules and macromolecules in sections of biological material with a resolution in the tens of nanometers and with a sensitivity approaching in principle that of a single protein. Here we use two different systems, crystals of glycine and mixtures of proteins, to show that the formation of recombinant CN secondary ions under Cs bombardment can be exploited to create a new colocalization technique. We show experimentally that the formation of the recombinant (13)C(15)N secondary ion between (13)C- and (15)N-labeled macromolecules is indeed an indicator of the distance between the interacting macromolecules and on their shape. We build up a convolution model of the mixing-recombination process in D-SIMS that allows quantitative interpretations of the distance-dependent formation of the recombinant CN. Our results show that macromolecules can be colocalized if they are within 2 nm of one another. We discuss the potential advantages of this new technique for biological applications.


Assuntos
Proteínas de Escherichia coli/química , Glicina/química , Modelos Biológicos , Espectrometria de Massa de Íon Secundário/métodos , Isótopos de Carbono , Cristalização , Escherichia coli/química , Escherichia coli/metabolismo , Proteínas de Escherichia coli/biossíntese , Proteínas de Escherichia coli/isolamento & purificação , Íons , Matemática , Isótopos de Nitrogênio
10.
J Neurosci Res ; 86(9): 1916-26, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18335522

RESUMO

Adult human and rodent brains contain neural stem and progenitor cells, and the presence of neural stem cells in the adult rodent spinal cord has also been described. Here, using electron microscopy, expression of neural precursor cell markers, and cell culture, we investigated whether neural precursor cells are also present in adult human spinal cord. In well-preserved nonpathological post-mortem human adult spinal cord, nestin, Sox2, GFAP, CD15, Nkx6.1, and PSA-NCAM were found to be expressed heterogeneously by cells located around the central canal. Ultrastructural analysis revealed the existence of immature cells close to the ependymal cells, which display characteristics of type B and C cells found in the adult rodent brain subventricular region, which are considered to be stem and progenitor cells, respectively. Completely dissociated spinal cord cells reproducibly formed Sox2(+) nestin(+) neurospheres containing proliferative precursor cells. On differentiation, these generate glial cells and gamma-aminobutyric acid (GABA)-ergic neurons. These results provide the first evidence for the existence in the adult human spinal cord of neural precursors with the potential to differentiate into neurons and glia. They represent a major interest for endogenous regeneration of spinal cord after trauma and in degenerative diseases.


Assuntos
Neuroglia/citologia , Neurônios/citologia , Medula Espinal/citologia , Medula Espinal/fisiologia , Células-Tronco/citologia , Adulto , Animais , Biomarcadores/metabolismo , Morte Encefálica , Técnicas de Cultura de Células , Diferenciação Celular , Humanos , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Neuroglia/fisiologia , Neurônios/fisiologia , Células-Tronco/fisiologia , Doadores de Tecidos
11.
Int J Androl ; 31(2): 194-200, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17971160

RESUMO

The link between endocrine disruptors and altered blood glucose homeostasis has been recently suggested. Epidemiological studies have correlated levels of phthalates, dioxins and persistent organic pollutants with alterations of blood glucose homeostasis in humans. Environmentally relevant doses of the ubiquitous endocrine disruptor bisphenol-A (BPA) have profound effects on mice endocrine pancreas--an essential tissue involved in glucose metabolism. BPA exerts rapid non-genomic effects on insulin releasing beta-cells and glucagon releasing alpha-cells within freshly isolated islets of Langerhans. In vivo, a single BPA injection of 10 microg/kg rapidly increases plasma insulin and concomitantly decreases glycaemia. When mice were treated with BPA 100 microg/kg/day for 4 days, the environmental oestrogen produced an increase in beta-cell insulin content along with a post-prandial hyperinsulinaemia and insulin resistance. The results reviewed here demonstrate that doses well below the current lowest observed adverse effect level considered by the US-EPA, disrupt pancreatic beta-cell function producing insulin resistance in male mice. Therefore, this altered blood glucose homeostasis by BPA exposure may enhance the risk of developing type II diabetes.


Assuntos
Glicemia/metabolismo , Disruptores Endócrinos/toxicidade , Homeostase , Pâncreas/efeitos dos fármacos , Fenóis/toxicidade , Animais , Compostos Benzidrílicos , Camundongos
12.
J Neurochem ; 104(1): 89-99, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17986232

RESUMO

Neuroblastoma is one of the most common cancers in children. Neuroblastoma differentiation is linked to the presence of the promyelocytic leukemia (PML) protein. Retinoic acid, a powerful differentiation-inducer in vitro, is a potent agent for the treatment of neuroblastoma. Using two different human neuroblastoma cell lines, SH-SY5Y and LA-N-5, we show here that PML protein leads to the formation of nuclear bodies (PML-NB) after only 1 h of retinoic acid treatment and that this formation is mediated by the extracellular signal-regulated kinase (ERK) pathway. Inhibition of protein kinase C also leads to formation of PML-NB via the ERK pathway. Both sumoylation and phosphorylation of PML in an ERK-dependent pathway are also required for formation of PML-NB. Finally, we show that PML-NB formation in neuroblastoma cells is associated with neurite outgrowth. These results support the proposal that the formation of PML-NB is correlated with the differentiation of neuroblastoma cells.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Estruturas do Núcleo Celular/metabolismo , Ceratolíticos/farmacologia , Proteínas de Neoplasias/metabolismo , Neuroblastoma/tratamento farmacológico , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Tretinoína/farmacologia , Proteínas Supressoras de Tumor/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Modelos Biológicos , Proteínas de Neoplasias/genética , Neuroblastoma/patologia , Proteínas Nucleares/genética , Fosforilação/efeitos dos fármacos , Proteína da Leucemia Promielocítica , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética
13.
Aliment Pharmacol Ther ; 25(7): 841-8, 2007 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-17373923

RESUMO

BACKGROUND: Hepatic venous pressure gradient (HVPG) has prognostic value in complications and survival of patients with liver cirrhosis. However, the relationship between HVPG and the outcome of acute alcoholic hepatitis (AAH), as well as the specific features of portal hypertension syndrome in this setting, have not been defined. AIMS: To evaluate the prognostic value of HVPG and to analyse the degree of portal hypertension and hyperdynamic circulation in patients with severe AAH. METHODS: Early measurements of HVPG were performed in 60 patients with severe AAH, and compared with the haemodynamic findings of 37 and 29 liver transplantation candidates with alcoholic or viral end-stage cirrhosis respectively. RESULTS: Twenty-three patients (38%) died during hospitalization. Portal hypertension and hyperdynamic circulation were more severe in AAH patients. HVPG was greater in non-survivors [26.9 (7.4) vs. 19.4 (5.2) mmHg, P < 0.001]. Only 4/31 (13%) patients with HVPG 22 (P < 0.001). Encephalopathy (OR 9.4; CI 1.4-64.8), Model for End-Stage Liver Disease (MELD) score > 25 (OR 7.4; CI 1.4-39.9) and HVPG > 22 mmHg (OR 6.7; CI 1.1-39.9) were independently associated to in-hospital mortality. CONCLUSIONS: Early measurement of HVPG provides important prognostic information on the short-term outcome of patients with severe AAH. In addition, MELD score also seems to be a strong prognostic factor in these patients.


Assuntos
Anti-Hipertensivos/uso terapêutico , Hepatite Alcoólica/mortalidade , Hipertensão Portal/fisiopatologia , Cirrose Hepática/mortalidade , Pressão Venosa/fisiologia , Feminino , Veias Hepáticas , Mortalidade Hospitalar , Humanos , Hipertensão Portal/tratamento farmacológico , Cirrose Hepática/fisiopatologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Análise de Regressão , Índice de Gravidade de Doença , Taxa de Sobrevida
14.
J Viral Hepat ; 13(9): 625-32, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16907850

RESUMO

Endoglin, a transforming growth factor (TGF)-beta1 co-receptor, has been associated with renal and cutaneous fibrosis, as overexpression of this protein has been observed in biopsies from patients with glomerulosclerosis and scleroderma, respectively. Our aim was to evaluate whether endoglin may be associated with hepatic fibrosis featuring chronic hepatitis C virus (HCV) infection. Fifty-two anti-HCV+ patients, five anti-HCV- patients and 27 healthy subjects were studied. Western blot and immunohistochemistry were used to quantify the expression levels of endoglin and TGF-beta1 in liver biopsy samples, and serum concentrations of endoglin and hyaluronic acid were determined by enzyme-linked immunosorbent assays (ELISAs). In patients with advanced fibrosis, intrahepatic expression levels of endoglin and TGF-beta1 were significantly higher than those in patients with early fibrosis (mean: 3- and 5.8-fold, respectively) and normal liver (mean: 3.9- and 12-fold, respectively). Interestingly, activated hepatic stellate cells as well as portal and septal myofibroblasts expressed endoglin. Serum levels of endoglin were also significantly higher in patients with advanced fibrosis than in those with early fibrosis (55.5 +/- 1.6 vs 47.5 +/- 0.9 ng/mL, P < 0.001), showing a positive correlation with serum hyaluronic acid concentrations (r = 0.57, P = 0.01). In conclusion, increased intrahepatic endoglin and TGF-beta1 expression is significantly associated with progressive hepatic fibrosis in chronic HCV infection. Circulating endoglin levels are elevated in HCV patients showing a significant correlation with histological and serum markers of hepatic fibrosis. These data suggest an active role for endoglin in the fibrotic process featuring chronic HCV infection.


Assuntos
Antígenos CD/análise , Hepatite C Crônica/complicações , Cirrose Hepática/complicações , Fígado/química , Receptores de Superfície Celular/análise , Adulto , Antígenos CD/sangue , Biomarcadores/análise , Biomarcadores/sangue , Western Blotting , Endoglina , Ensaio de Imunoadsorção Enzimática , Feminino , Fibrose , Hepatite C Crônica/sangue , Hepatite C Crônica/metabolismo , Humanos , Ácido Hialurônico/sangue , Imuno-Histoquímica , Cirrose Hepática/sangue , Cirrose Hepática/metabolismo , Masculino , Pessoa de Meia-Idade , Receptores de Superfície Celular/sangue
15.
Anal Chem ; 78(8): 2471-7, 2006 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-16615752

RESUMO

We describe the measurement, at 100 K, of the SIMS relative sensitivity factors (RSFs) of the main physiological cations Na+, K+, Mg2+, and Ca2+ in frozen-hydrated (F-H) ionic solutions. Freezing was performed by either plunge freezing or high-pressure freezing. We also report the measurement of the RSFs in flax fibers, which are a model for ions in the plant cell wall, and in F-H ionic samples, which are a model for ions in the vacuole. RSFs were determined under bombardment with neutral oxygen (FAB) for both the fibers and the F-H samples. We show that referencing to ice-characteristic secondary ions is of little value in determining RSFs and that referencing to K is preferable. The RSFs of Na relative to K and of Ca relative to Mg in F-H samples are similar to their respective values in fiber samples, whereas the RSFs of both Ca and Mg relative to K are lower in fibers than in F-H samples. Our data show that the physical factors important for the determination of the RSFs are not the same in F-H samples and in homogeneous matrixes. Our data show that it is possible to perform a SIMS relative quantification of the cations in frozen-hydrated samples with an accuracy on the order of 15%. Referencing to K permits the quantification of the ionic ratios, even when the absolute concentration of the referencing ion is unknown. This is essential for physiological studies of F-H biological samples.

16.
Plant Signal Behav ; 1(1): 9-14, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19521470

RESUMO

Plants are sensitive to stimuli from the environment (e.g., wind, rain, contact, pricking, wounding). They usually respond to such stimuli by metabolic or morphogenetic changes. Sometimes the information corresponding to a stimulus may be "stored" in the plant where it remains inactive until a second stimulus "recalls" this information and finally allows it to take effect. Two experimental systems have proved especially useful in unravelling the main features of these memory-like processes.In the system based on Bidens seedlings, an asymmetrical treatment (e.g., pricking, or gently rubbing one of the seedling cotyledons) causes the cotyledonary buds to grow asymmetrically after release of apical dominance by decapitation of the seedlings. This information may be stored within the seedlings, without taking effect, for at least two weeks; then the information may be recalled by subjecting the seedlings to a second, appropriate, treatment that permits transduction of the signal into the final response (differential growth of the buds). Whilst storage is an irreversible, all-or-nothing process, recall is sensitive to a number of factors, including the intensity of these factors, and can readily be enabled or disabled. In consequence, it is possible to recall the stored message several times successively.In the system based on flax seedlings, stimulation such as manipulation stimulus, drought, wind, cold shock and radiation from a GSM telephone or from a 105 GHz Gunn oscillator, has no apparent effect. If, however, the seedlings are subjected at the same time to transient calcium depletion, numerous epidermal meristems form in their hypocotyls. When the calcium depletion treatment is applied a few days after the mechanical treatment, the time taken for the meristems to appear is increased by a number of days exactly equal to that between the application of the mechanical treatment and the beginning of the calcium depletion treatment. This means that a meristem-production information corresponding to the stimulation treatment has been stored in the plants, without any apparent effect, until the calcium depletion treatment recalls this information to allow it to take effect. Gel electrophoresis has shown that a few protein spots are changed (pI shift, appearance or disappearance of a spot) as a consequence of the application of the treatments that store or recall a meristem-production signal in flax seedlings. A SIMS investigation has revealed that the pI shift of one of these spots is probably due to protein phosphorylation. Modifications of the proteome have also been observed in Arabidopsis seedlings subjected to stimuli such as cold shock or radiation from a GSM telephone.

17.
Nutr Hosp ; 20(1): 26-37, 2005.
Artigo em Espanhol | MEDLINE | ID: mdl-15762417

RESUMO

Inflammatory bowel disease is a chronic disease with an unknown ethiology although multiple factors intervene such as individual, genetic and immunologic susceptibility, as well as different environmental factors. Like other multisystemic diseases, its clinical manifestations are diverse and it may affect other organs besides the gastrointestinal tract. In the last few years there is a growing interest for one of these extraintestinal manifestations, osteoporosis and osteopenia that may affect up to 42% of patients and can condition an important increase in morbility. Inactivity, prolonged corticosteroid treatment, nutritional deficiencies and the disease per se have an important role in the development of this complication. This article reviews clinical and ethiological aspects of inflammatory bowel disease associated osteoporosis and offers a strategy for diagnosis and treatment.


Assuntos
Doenças Inflamatórias Intestinais/complicações , Osteoporose/etiologia , Absorciometria de Fóton , Densidade Óssea , Ensaios Clínicos como Assunto , Humanos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Osteoporose/diagnóstico , Osteoporose/tratamento farmacológico
18.
Med Hypotheses ; 64(2): 241-7, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15607547

RESUMO

The precise etiologic mechanisms involved in the premature rupture of membranes (PROM) during pregnancy, the main cause of preterm delivery worldwide, are unknown. Previous studies have shown that: (a) the rupture of chorioamniotic membranes is related to an imbalance between synthesis and degradation of collagen induced by the overexpression/activity of various matrix metalloproteinases (MMP); (b) during human labor and delivery the expression of prolactin receptors (PRL-R) increases in chorioamniotic membranes, decidua and placenta; (c) prolactin (PRL) can influence the synthesis of prostaglandins, the expression of some MMP (MMP-2, MMP-9 and decysin) and tissue inhibitors of MMP in general; (d) vitamin C deficiency induces the expression/activity of extracellular MMP and is considered a risk factor for PROM; and (e) vitamin C potentiates the dopamine-mediated inhibition of PRL in rats. The present hypothesis proposes that a decreased hypothalamic dopaminergic tone-and thus an increased synthesis/release of pituitary PRL - is induced by vitamin C deficiency below a critical threshold (<18 microg/10(8) leukocytes) and that both factors, in turn, would cause upregulation of the expression/activity of several MMP. The increased PRL concentrations (acting like a Th1-type cytokine) along with the overexpression of other proinflammatory cytokines would induce a premature switch from a favorable Th2-type immune response to a noxious Th1-type immune response in the intrauterine environment. This change, in conjunction with the upregulation of MMP-2 and MMP-9, would cause a premature imbalance between synthesis/degradation of collagen in chorioamniotic membranes (an "anticipation" of the normal parturition cascade?), which favors extracellular matrix degradation, proposed as the most relevant event in the genesis of PROM. This hypothesis represents a new dimension in the study of the etiology of PROM.


Assuntos
Deficiência de Ácido Ascórbico/complicações , Ruptura Prematura de Membranas Fetais/etiologia , Regulação da Expressão Gênica , Prolactina/metabolismo , Deficiência de Ácido Ascórbico/metabolismo , Feminino , Ruptura Prematura de Membranas Fetais/imunologia , Ruptura Prematura de Membranas Fetais/metabolismo , Humanos , Ativação Linfocitária/imunologia , Metaloproteinases da Matriz/metabolismo , Gravidez , Prostaglandinas/metabolismo , Células Th2/imunologia
19.
Plant Biol (Stuttg) ; 6(5): 590-7, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15375730

RESUMO

When subjected to an appropriate asymmetric stimulus, seedlings of Bidens pilosa L. "store" a symmetry-breaking instruction that will finally take effect (in the form of a differential growth of the cotyledonary buds) only if the plants are in a state in which they can "recall" this information. The ability of the plants to recall the stored symmetry-breaking instruction may be switched "on" or "off" by the application of a variety of stimuli. Although its detailed phenomenology is rather complicated, the overall behaviour of the plant storage/recall system can be modelled by use of an asynchronous, logical (discrete) description involving positive and negative feedback circuits, which are required for the existence of multi-stationarity and stability, respectively. The state tables, as used in this formalism, give a concise and easy-to-handle description of the evolution of the system and make it particularly easy to determine its stable states. This modelling approach may be extended to the formulation of many other experimental systems.


Assuntos
Desenvolvimento Vegetal , Relógios Biológicos , Meio Ambiente , Retroalimentação , Modelos Biológicos , Fenômenos Fisiológicos Vegetais , Plântula/crescimento & desenvolvimento , Transdução de Sinais
20.
Rev Esp Enferm Dig ; 96(5): 315-21, 2004 May.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-15180443

RESUMO

INTRODUCTION: argon-plasma coagulation (APC) has been used safely and efficaciously in multiple settings including colon polyp treatment. The aim of this study was to evaluate APC efficacy and safety in the treatment of flat colorectal adenomas. MATERIALS AND METHODS: APC ablation was prospectively performed and evaluated in 22 consecutive patients with colorectal adenomas, 11 of which had large sessile adenomas that were treated with piecemeal polypectomy and APC ablation of residual adenomatous tissue, whereas the remaining eleven patients with flat or carpet-like adenomas were only treated with APC. The mean initial longitudinal extension of adenomas to be treated with APC was 22 mm (range, 20 to 40 mm). RESULTS: the mean age of patients was 70 years. Adenomas were found most frequently in the rectum (50%) and cecum (23%). Complete ablation was achieved in 90.9% of adenomas. Recurrence was observed in 20% of patients, all of them in the rectum, after a mean follow-up period of 16.3 months (range, 8 to 35). All recurrences were managed satisfactorily. No major complications were seen. CONCLUSIONS: argon plasma coagulator ablation of flat colorectal adenomas is an efficacious and safe technique, specially in the right colon, but results must be confirmed in controlled trials with a higher number of patients.


Assuntos
Adenoma/cirurgia , Neoplasias Colorretais/cirurgia , Pólipos Intestinais/cirurgia , Fotocoagulação a Laser , Idoso , Idoso de 80 Anos ou mais , Colonoscopia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
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