PubMed Health⌕ Search

Biomedical subjects

Isabel Azevedo

Publications and source records attributed to Isabel Azevedo.

7 recordsLinked to original sources
PubMed2005

Effect of red wine on the intestinal absorption of thiamine and folate in the rat: comparison with the effect of ethanol alone.

BACKGROUND: This work aimed to investigate, in the rat, the acute in vitro effect of red wine and the effect of chronic red wine ingestion on the intestinal absorption of thiamine and folate and to compare them with the effects of ethanol alone. METHODS: The effects of red wine and of an ethanol solution (same ethanol concentration as that in the red wine, i.e., 12% [v/v]) on rat jejunal apparent permeability (Papp) to H-thiamine and H-folate in the mucosal-to-serosal direction were investigated. Red wine and ethanol were tested both chronically (21-day consumption) and acutely in vitro. RESULTS: Acutely, both red wine and ethanol 12% (v/v) (both diluted 1:5) reduced (to 65 and 60% of control, respectively) the mucosal-to-serosal Papp to H-thiamine across rat jejunum. Chronic (21-day) ethanol (12% [v/v]) consumption also decreased the Papp to H-thiamine (to 33% of control), but red wine consumption for the same period did not change it. Mucosal-to-serosal Papp to H-folate across rat jejunum was not changed by chronic ingestion of red wine or ethanol. Similarly, it was not affected by acute exposition of the tissue to red wine or ethanol. Acute ethanol (0.05% [v/v]) did not affect the Papp to H-thiamine or H-folate in jejunal tissues obtained from control and red wine-treated rats, but it significantly increased the Papp to both H-thiamine and H-folate (to 183 and 197% of control, respectively) in tissues from chronically ethanol-treated rats. CONCLUSIONS: Acute and chronic red wine or ethanol had no effect on the intestinal absorption of folate. However, ethanol, both acutely and chronically, decreased the jejunal absorption of thiamine, and red wine reduced the jejunal absorption of thiamine, but only when tested acutely. These findings show that it is not correct to extrapolate from results obtained with ethanol alone on intestinal permeability to the effect of alcoholic beverage consumption.

Animals↗
PubMed2005

Epidemiology of heart failure in primary care in Madeira: the EPICA-RAM study.

UNLABELLED: Chronic heart failure (CHF) is a serious public health problem all over the world. CHF has a high prevalence, affecting mainly the elderly, and causes severe disability and social and economic costs. AIM: To estimate the prevalence of chronic heart failure in the Autonomous Region of Madeira in 2001. METHODS: This was a community-based epidemiological survey involving subjects attending primary care centers selected by a combined two-stage sampling and stratifying procedure. General practitioners (GPs) randomly selected in proportion to the population of each municipality evaluated subjects aged over 25 years attending primary care centers, recruited consecutively and stratified by age. CHF cases were identified according to the Guidelines of the European Society of Cardiology for CHF diagnosis. RESULTS: Six hundred and eighty-six eligible subjects were evaluated by 30 GPs; 60 patients with CHF were identified. The overall prevalence and 95 % CI of CHF in Madeira was 4.69 % (2.91 % to 6.46 %), 3.53 % in males (0.81 % to 6.26 %), and 5.58 % in females (3.37 % to 7.79 %). CHF prevalence increases with age: 1.24 % (0.00 % to 2.96 %) in the 25 to 49-year-old group, 6.17% (1.31 to 11.03 %) in those aged 50 to 59 years, 7.62 % (0.75 to 14.49 %) in those aged 60 to 69 years, 13.32 % (7.99 % to 14.49 %) in the 70 to 79-year-old group, and 14.34 % in the group over 80 years old (7.59 % to 21.09 %). The prevalence of CHF due to systolic dysfunction was 0.76 % and 2.74 % with normal systolic function. CONCLUSIONS: The overall prevalence of CHF in Madeira was similar to that of mainland Portugal, and slightly higher than that of other European studies. Overall CHF prevalence increases sharply with age. The prevalence of CHF with preserved systolic ventricular function was similar to that reported by other recent European studies. The prevalence of CHF due to systolic dysfunction was much lower. The differences found may correspond to differences in methodology rather than actual differences in the population. CHF with left ventricular systolic dysfunction seems to be rare in primary care in Madeira. This may be related to the different public health organization in Madeira, and deserves further evaluation.

Adult↗
PubMed2004

Changes in rat cerebral mitochondrial succinate dehydrogenase activity after brain trauma.

The objective of this study was to evaluate 2,3,5-triphenyltetrazolium chloride (TTC) staining in the brain tissue of rats submitted to a closed head traumatic injury, in comparison to control rats not submitted to trauma. The closed head, weight drop trauma model described by Marmarou et al. (1994) was used. Animals were all sacrificed 24 h after trauma. Staining of cerebral coronal slices using TTC, coupled to image analysis software, was used to measure the level of staining. An ultrastructural study of the brain region underneath the impact zone, as well as from the correspondent region of control rats, was also done. The TTC image analysis revealed a significant decrease in the percentage of white area, in traumatized rats (mean +/- SEM 23.93% +/- 2.26, n = 4 for control, 12.13% +/- 1.72, n = 9 for traumatized rats, p <.05). The ultrastructural analysis revealed that the number of axons showing at least one mitochondrion was significantly higher in the trauma group (mean +/- SEM 49.3%, n = 4 rats, 75 photographs, 2443 axons) than in control groups (23%, n = 3 rats, 30 photographs, 6220 axons (p <.001). Another difference observed was the larger mitochondrial size in the axons of traumatized rats (mean diameter +/- SEM 0.520 +/- 0.003 microm) compared to the controlled rats (0.368 +/- 0.006 microm; p <.001). The ultrastructural observation of the traumatized brain revealed a significantly higher number of peroxisomes per photograph (mean number +/- SEM 10.58 +/- 1.18, n = 75) compared to the control group (0.19 +/- 0.08, n = 30, p <.001). The results indicate an increase of mitochondrial and peroxysomal relative mass, with a higher succinate dehydrogenase activity, 24 h after the induction of traumatic brain injury.

Animals↗
PubMed2003

Effect of thiamine on 3H-MPP+ uptake by Caco-2 cells.

Recent studies on the intestinal uptake of the organic cation 1-methyl-4-phenylpyridinium (MPP+) showed that transport of this compound occurs through human extraneuronal monoamine transporter (hEMT). Moreover, it was recently described that alkaline phosphatase (ALP), an ecto-phosphatase anchored to the plasma membrane and able to dephosphorylate extracellular substrates or cell-surface proteins, is directly or indirectly involved in the modulation of MPP+ uptake by Caco-2 cells. The present study investigated a putative modulation of MPP+ intestinal apical uptake and ecto-ALP activity by thiamine (T+) and thiamine pyrophosphate (TPP, a T+ dietary precursor). For this purpose, we used Caco-2 cells, an enterocyte-like cell line derived from a human colonic adenocarcinoma, as an intestinal model. Ecto-ALP activity and N-[methyl-3H]-4-phenylpyridinium acetate (3H-MPP+) uptake were evaluated in intact Caco-2 cells. T+ and TPP were able to increase ecto-ALP activity, with an equal potency, and to decrease 3H-MPP+ apical uptake, with a similar potency. The effects of both compounds on ecto-ALP activity and 3H-MPP+ uptake were concentration-dependent. The results suggest that the effect of T+ and TPP on ecto-ALP activity may lead to inhibition of the intestinal absorption of other organic cations present in the diet. Another important conclusion is that the intestinal absorption of T+ may occur through hEMT, in Caco-2 cells.

1-Methyl-4-phenylpyridinium↗
PubMed2002

Being human.

Explore the source record for details and available documents.

Animals↗
PubMed2002

Uptake of (3)H-1-methyl-4-phenylpyridinium ((3)H-MPP(+)) by human intestinal Caco-2 cells is regulated by phosphorylation/dephosphorylation mechanisms.

Several transmembrane transporters of organic compounds are regulated by phosphorylation/dephosphorylation mechanisms. The aim of this study was to investigate the possible regulation of the intestinal uptake of organic cations by these mechanisms. The intestinal apical uptake of 1-methyl-4-phenylpyridinium (MPP(+)) was studied by incubating Caco-2 cells at 37 degrees for 5 min with 200 nM (3)H-MPP(+). Uptake of (3)H-MPP(+) by Caco-2 cells was not affected by activators of protein kinase G, and was not affected or slightly reduced (by 15-20%) by activators of protein kinase A or protein kinase C. Uptake of (3)H-MPP(+) by Caco-2 cells was reduced in a concentration-dependent manner by non-selective phosphodiesterase inhibitors (3-isobutyl-1-methylxanthine (IBMX), caffeine, teophylline). The IC(50) of IBMX was found to be 119 microM (102-138; n=9). Uptake of (3)H-MPP(+) by Caco-2 cells was not affected by inhibition of protein tyrosine kinase, but it was concentration-dependently reduced in the presence of inhibitors of mitogen-activated protein kinase. Uptake of (3)H-MPP(+) by Caco-2 cells was strongly reduced by Ca(2+)/calmodulin-mediated pathway inhibitors, but it was not dependent on extracellular Ca(2+). Our results suggest that the intestinal apical uptake of MPP(+) is regulated by phosphorylation/dephosphorylation mechanisms, being most probably active in the dephosphorylated state. Moreover, uptake of (3)H-MPP(+) by Caco-2 cells and by the extraneuronal monoamine transporter (EMT) are regulated in a very similar manner, suggesting an important participation of EMT in the intestinal uptake of this compound.

1-Methyl-4-phenylpyridinium↗