1
|
Manco L, Ribeiro ML, Máximo V, Almeida H, Costa A, Freitas O, Barbot J, Abade A, Tamagnini G. A new PKLR gene mutation in the R-type promoter region affects the gene transcription causing pyruvate kinase deficiency. Br J Haematol 2000; 110:993-7. [PMID: 11054094 DOI: 10.1046/j.1365-2141.2000.02283.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mutations in the PKLR gene responsible for pyruvate kinase (PK)-deficient anaemia are mainly located in the coding regions: 11 are in the splicing sites and, recently, three mutations have been described in the promoter region. We now report a novel point mutation A-->G on nucleotide 72, upstream from the initiation codon of the PKLR gene, in four Portuguese PK-deficient patients. This new regulatory mutation occurs within the most proximal of the four GATA motifs (GATA-A element) in the R-type promoter region. In two patients who were homozygous for this mutation, a semiquantitative reverse transcription polymerase chain reaction (PCR) procedure was used to evaluate the amount of R-PK mRNA transcript in the reticulocytes. The mRNA level was about five times lower than in normal controls, demonstrating that the PKLR gene transcription is severely affected, most probably because the -72A-->G point mutation disables the binding of the erythroid transcription factor GATA-1 to the GATA-A element. Supporting these data, the two patients homozygous for the -72A-->G mutation had severe haemolytic anaemia and were transfusion dependent until splenectomy. Two other patients who were compound heterozygous for this mutation and the previously described missense mutation 1456C-->T had a mild condition.
Collapse
|
|
25 |
42 |
2
|
Manco L, Ribeiro ML, Almeida H, Freitas O, Abade A, Tamagnini G. PK-LR gene mutations in pyruvate kinase deficient Portuguese patients. Br J Haematol 1999; 105:591-5. [PMID: 10354117 DOI: 10.1046/j.1365-2141.1999.01387.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In nine unrelated Portuguese patients with pyruvate kinase (PK) deficient anaemia, whose symptoms ranged from a mild chronic haemolytic anaemia to a severe anaemia presenting at birth and requiring multiple transfusions, the PK-LR gene mutations were identified and correlated with their phenotypes. Five different mutations were identified, three of them for the first time: a missense mutation 1670G --> C on exon 12 and two 5' splice donor site (GT) mutations on intron 8 [IVS8(+2)T --> G] and intron 10 [IVS10(+1)G --> C]. Two previously described missense mutations, 1456C --> T and 993C --> A, were also found. The genotype/phenotype correlation showed that patients with two missense mutations or with a missense mutation and a splicing mutation had a mild haemolytic anaemia. The three patients with severe anaemia, who were transfusion dependent until splenectomy, were homozygous for the splicing site mutations IVS10(+1)G --> C or IVS8(+2)T --> G.
Collapse
|
|
26 |
25 |
3
|
Guedes-Martins L, Matos L, Soares A, Silva E, Almeida H. AGEs, contributors to placental bed vascular changes leading to preeclampsia. Free Radic Res 2013; 47 Suppl 1:70-80. [PMID: 23796030 DOI: 10.3109/10715762.2013.815347] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Glycation of proteins or other biomolecules and their further long-term degradation result in the formation of advanced glycation end products, AGEs. AGEs and other ligands interact with their receptors, RAGEs, localized to a variety of tissues, but mainly in endothelium and vascular wall cells. This interaction triggers diverse signaling pathways that converge on the activation of NF-κB and the initiation of a local inflammatory reaction that, when prolonged, results in dysfunctional features. Preeclampsia is a serious vascular disorder centred at the placenta-uterine interface, the placental bed, but the condition extends to the mother's circulation. RAGEs have notorious expression in the placental bed tissues along pregnancy but, in addition, RAGEs and their ligands are expressed in the fetal membranes and are found in the amniotic fluid and the mother's serum. Disorders complicating pregnancies and having an important vascular involvement, as preeclampsia and diabetes mellitus, have additional enhanced AGE/RAGE expression variation. This indicates that for their assessment, the assay of RAGEs or their ligands may become useful diagnostic or prognostic procedures.
Collapse
|
Review |
12 |
25 |
4
|
Santos JL, Almeida H, Cerski CT, Silveira TR. Histopathological diagnosis of intra- and extrahepatic neonatal cholestasis. Braz J Med Biol Res 1998; 31:911-9. [PMID: 9698754 DOI: 10.1590/s0100-879x1998000700005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The histopathology of the liver is fundamental for the differential diagnosis between intra- and extrahepatic causes of neonatal cholestasis. However, histopathological findings may overlap and there is disagreement among authors concerning those which could discriminate between intra- and extrahepatic cholestasis. Forty-six liver biopsies (35 wedge biopsies and 11 percutaneous biopsies) and one specimen from a postmortem examination, all from patients hospitalized for neonatal cholestasis in the Pediatrics Service of Hospital de Clínicas de Porto Alegre, were prospectively studied using a specially designed histopathological protocol. At least 4 of 5 different stains were used, and 46 hepatic histopathological variables related to the differential diagnosis of neonatal cholestasis were studied. The findings were scored for severity on a scale from 0 to 4. Sections which showed less than 3 portal spaces were excluded from the study. Sections were examined by a pathologist who was unaware of the final diagnosis of each case. Bile tract permeability was defined by scintigraphy of the bile ducts and operative cholangiography. The F test and discriminant analysis were used as statistical methods for the study of the hepatic histopathological variables. The chi-square method with Yates correction was used to relate the age of the patients on the date of the histopathological study to the discriminatory variables between intra- and extrahepatic cholestasis selected by the discriminant function test. The most valuable hepatic histopathological variables for the discrimination between intra- and extrahepatic cholestasis, in decreasing order of importance, were periportal ductal proliferation, portal ductal proliferation, portal expansion, cholestasis in neoductules, foci of myeloid metaplasia, and portal-portal bridges. The only variable which pointed to the diagnosis of intrahepatic cholestasis was myeloid metaplasia. Due to the small number of patients who were younger than 60 days on the date of the histopathological study (N = 6), no variable discriminated between intra- and extrahepatic cholestasis before the age of 2 months and all of them, except for the portal expansion, were discriminatory after this age. In infants with cholestasis, foci of myeloid metaplasia, whenever present in the liver biopsy, suggested intrahepatic cholestasis. Periportal ductal proliferation, portal ductal proliferation, portal expansion, cholestasis in neoductules, portal cholestasis and portal-portal bridges suggested extrahepatic obstructive cholestasis.
Collapse
|
|
27 |
16 |
5
|
Rocha B, Rodrigues AR, Tomada I, Martins MJ, Guimarães JT, Gouveia AM, Almeida H, Neves D. Energy restriction, exercise and atorvastatin treatment improve endothelial dysfunction and inhibit miRNA-155 in the erectile tissue of the aged rat. Nutr Metab (Lond) 2018; 15:28. [PMID: 29686722 PMCID: PMC5902942 DOI: 10.1186/s12986-018-0265-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/03/2018] [Indexed: 02/06/2023] Open
Abstract
Background Endothelial dysfunction underlies cardiovascular disease that frequently affects aged individuals. Characterized by local decrease in nitric oxide, it results from down-regulation of endothelial nitric oxide synthase (eNOS) expression/activity. Aiming to elucidate the molecular mechanisms involved in age-related endothelial dysfunction and to unveil potential therapeutic targets, we tested how diet pattern, exercise and atorvastatin modulate the expression of eNOS, inducible NOS (iNOS), endothelin-1, sirtuins (SIRT) and microRNA-155 in the erectile tissue of high-fat fed aged rats. Methods Sprague-Dawley male rats fed with high-fat diet until they completed 12 months were grouped and subjected to energy restriction (ER), ER and atorvastatin, or, ER, atorvastatin and physical exercise. Controls were fed with standard rodent chow. The blood pressure was measured using the tail-cuff method before sacrifice at 18 months. Glucose, total cholesterol, HDL, triglyceride and CRP were assessed in blood and eNOS, endothelin-1, iNOS and sirtuins were detected by immunofluorescence in the penis sections; eNOS, endothelin-1, iNOS, SIRT2-4 and SIRT6-7 were semi-quantified by western blotting in tissue homogenates. MicroRNA-155 was quantified using RT-PCR in formalin-fixed paraffin embedded sections. To compare the studied variables, two-tail student t test was used. Results Atorvastatin promotes eNOS expression and is more efficient than ER or exercise in the control of hyperlipidemia and inflammation. Among the studied sirtuins, detected for the first time in the erectile tissue of the aged rat, SIRT2 aligns with eNOS expression. Both proteins exhibit over-expression in animals with combined exercise, atorvastatin and ER. Analysis of microRNA-155 expression also suggests its intervention in the regulation of eNOS expression. ER, particularly when combined with atorvastatin, was able to reverse the increase of iNOS and endothelin-1 in high-fat fed rats. Conclusions The present results indicate that the association of ER, atorvastatin and exercise is more efficient than isolated interventions in the prevention of endothelial dysfunction.
Collapse
|
Journal Article |
7 |
15 |
6
|
Ribeiro ML, Gonçalves P, Cunha E, Bento C, Almeida H, Pereira J, Núñez GM, Tamagnini GP. Genetic heterogeneity of beta-thalassemia in populations of the Iberian Peninsula. Hemoglobin 1997; 21:261-9. [PMID: 9140722 DOI: 10.3109/03630269708997387] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
|
28 |
14 |
7
|
Cunha S, Almeida H, Amaral MH, Lobo JMS, Silva AC. Intranasal lipid nanoparticles for the treatment of neurodegenerative diseases. Curr Pharm Des 2017; 23:CPD-EPUB-87105. [PMID: 29189138 DOI: 10.2174/1381612824666171128105305] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 11/10/2017] [Accepted: 11/15/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND Current treatments for neurodegenerative diseases are challenging, due to the absence of full effective medicines. One of the major problems associated to these is the occurrence of non-targeting events, which leads to adverse effects and requires frequent dose administration. METHODS Researches have been performed to develop new drug delivery systems administrated by alternative routes. For example, the direct nose-to-brain delivery of drugs by means of lipid nanoparticles, such as solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), have been showing promising results. RESULTS Among the advantages of intranasal administration is the avoidance of passing the blood-brain barrier (BBB) to reach the central nervous system (CNS), allowing the direct delivery of drugs to the brain by a non-invasive way, minimizing systemic exposure and prolonging residence time. This review article discusses the advantages of using SLN and NLC for direct nose-to-brain drug delivery. A brief reference to other lipid-based carriers (liposomes, nanoemulsions and microemulsions) is also provided. CONCLUSION The benefits of using SLN and NLC for improve nasal drug delivery have been demonstrated by in vitro, ex vivo and in vivo experiments. However, more in vivo animal studies are needed for advance to human clinical trials and reach clinics.
Collapse
|
|
8 |
13 |
8
|
Guedes-Martins L, Cunha A, Saraiva J, Gaio R, Macedo F, Almeida H. Internal iliac and uterine arteries Doppler ultrasound in the assessment of normotensive and chronic hypertensive pregnant women. Sci Rep 2014; 4:3785. [PMID: 24445576 PMCID: PMC3896929 DOI: 10.1038/srep03785] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 01/02/2014] [Indexed: 11/21/2022] Open
Abstract
The objective of this work was to compare Doppler flows pulsatility index (PI) and resistance indexes (RI) of uterine and internal iliac arteries during pregnancy in low risk women and in those with stage-1 essential hypertension. From January 2010 and December 2012, a longitudinal and prospective study was carried out in 103 singleton uneventful pregnancies (72 low-risk pregnancies and 31 with stage 1 essential hypertension)at the 1st, 2nd and 3rd trimesters. Multiple linear regression models, fitted using generalized least squares and whose errors were allowed to be correlated and/or have unequal variances, were employed; a model for the relative differences of both arteries impedance was utilized. In both groups, uterine artery PI and RI exhibited a gestational age related decreasing trend whereas internal iliac artery PI and RI increased. The model testing the hemodynamic adaptation in women with and without hypertension showed similar trend. Irrespective of blood pressure conditions, the internal iliac artery resistance pattern contrasts with the capacitance pattern of its immediate pelvic division, suggesting a pregnancy-related regulatory mechanism in the pelvic circulation.
Collapse
|
Research Support, Non-U.S. Gov't |
11 |
12 |
9
|
de Araújo Padilha CE, Dantas PVF, Nogueira CDC, Leitão ALDS, Almeida HN, de Santana Souza DF, Oliveira JAD, de Macedo GR, dos Santos ES. Enhancing the recovery and concentration of polyphenols from camu-camu (Myrciaria dubia H.B.K. McVaugh) by aqueous two-phase flotation and scale-up process. SEP SCI TECHNOL 2018. [DOI: 10.1080/01496395.2018.1442865] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
|
7 |
12 |
10
|
Pignatelli D, Pinto P, Almeida H, Magalhães MM, Magalhães MC, Ho MM, Vinson GP. The development of the adrenal cortex in the rat. An immunohistochemical study. Endocr Res 1995; 21:129-36. [PMID: 7588374 DOI: 10.3109/07435809509030429] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The Inner Zone Antibody (IZAb) is a monoclonal antibody which interacts with an antigen found predominantly in rat adrenal inner cortical zones. Since its expression increases after ACTH treatment the antigen may have a role in steroidogenesis although, so far, this has not yet been fully characterised. Due to its molecular weight, it cannot be any of the known cytochrome P450 proteins. In this study we examined the expression of IZAb in male and female rats throughout their postnatal development and in aged animals. In a different set of animals, blood was collected for hormonal assays and the adrenals stained with classical methods. The staining with IZAb was clear from the first post-natal day. The zona glomerulosa which was always present at birth, was easily distinguished and unstained. The staining in the inner zone cells was fainter at birth and increased progressively until postnatal day 20. Afterwards these cells were remarkably stained at all ages. Medullary cells were also present from birth although they were generally found in clusters instead of constituting a well defined zone. Cortical cells appeared in the medullary zone at all ages after its complete development. The zona glomerulosa increased in size until approximately postnatal day 40 while the inner zones increased until day 70. The area of the cortex was significantly different between the two sexes from day 50 onwards and this was predominantly due to differences in the zona fasciculata. Corticosterone levels increased until approximately day 25 in the male rat and until day 45 in the female.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
|
30 |
7 |
11
|
Braga RM, Queiroga TS, Calixto GQ, Almeida HN, Melo DMA, Melo MAF, Freitas JCO, Curbelo FDS. The energetic characterization of pineapple crown leaves. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:18987-18993. [PMID: 26233737 DOI: 10.1007/s11356-015-5082-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Accepted: 07/15/2015] [Indexed: 06/04/2023]
Abstract
Energetic characterization of biomass allows for assessing its energy potential for application in different conversion processes into energy. The objective of this study is to physicochemically characterize pineapple crown leaves (PC) for their application in energy conversion processes. PC was characterized according to ASTM E871-82, E1755-01, and E873-82 for determination of moisture, ash, and volatile matter, respectively; the fixed carbon was calculated by difference. Higher heating value was determined by ASTM E711-87 and ash chemical composition was determined by XRF. The thermogravimetric and FTIR analyses were performed to evaluate the thermal decomposition and identify the main functional groups of biomass. PC has potential for application in thermochemical processes, showing high volatile matter (89.5%), bulk density (420.8 kg/m(3)), and higher heating value (18.9 MJ/kg). The results show its energy potential justifying application of this agricultural waste into energy conversion processes, implementing sustainability in the production, and reducing the environmental liabilities caused by its disposal.
Collapse
|
|
10 |
7 |
12
|
Rodrigues AR, Sousa D, Almeida H, Gouveia AM. Cell surface targeting of the Melanocortin 5 Receptor (MC5R) requires serine-rich terminal motifs. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1217-1226. [PMID: 28396017 DOI: 10.1016/j.bbamcr.2017.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 04/05/2017] [Accepted: 04/07/2017] [Indexed: 01/11/2023]
Abstract
The Melanocortin 5 Receptor (MC5R) is a cell surface receptor that belongs to the class of G-protein coupled receptors (GPCRs), which comprises an intracellular carboxylic domain, seven transmembrane helices and an extracellular amino terminal. Over the last few years, MC5R has been implicated in the regulation of lipid metabolism in exocrine glands, muscle and even in adipose tissue and its function is quite dependent on its correct cell membrane targeting. In this context, the purpose of this work was to study the role of MC5R N-terminus in the receptor trafficking from the endoplasmic reticulum (ER) through the Golgi complex to the plasma membrane. Analysis of N-terminal deleted forms of MC5R revealed that the first 21 amino acids contain the information responsible for the receptor cell surface expression and the removal of further amino acids interfere with the receptor synthesis. In this setting, several mutant forms of the receptor were created by site directed mutagenesis of the MC5R first 21 amino acids and their presence at the plasma membrane was assessed. We have found that two small motifs, constituted by residues Ser4/Ser5 and Ser17/Glu18, are clearly involved in the correct targeting of MC5R to the cell surface. Fluorescence microscopy analysis has revealed that MC5R constructs with mutations in those residues are mainly retained at the ER/Golgi complex. Furthermore, the homodimerization ability of the receptor is maintained in these mutant forms, suggesting that other mechanisms are involved in the regulation of the anterograde transport of MC5R by those N-terminal domains.
Collapse
|
Research Support, Non-U.S. Gov't |
8 |
6 |
13
|
Almeida H, Magalhães MC, Magalhães MM. Age-related changes in lipid peroxidation products in rat adrenal gland. AGE 1998; 21:119-121. [PMID: 23604369 PMCID: PMC3455689 DOI: 10.1007/s11357-998-0018-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Chloroform-methanol extracts from rat adrenals at five different ages (2, 6, 12, 18 and 24 months), were studied by fluorescence. After obtaining excitation and emission spectra, fluorescence intensity was measured at 365 nm excitation and 455 emission for all time points of aging. An additional study of lipid peroxidation employing a thiobarbituric acid reaction was made. Fluorescence intensity increased during aging from 16.39 × 10(3) arbitrary units of fluorescence per gram of tissue at 2 months, to 34.33 × 10(3) units at 24 months. Thiobarbituric acid reaction products expressed in nmol of malondialdehyde per gram of adrenal increased from 172.97 at 2 months to 640.83 at 24 months. One way analysis of variance revealed a statistically significant difference (p<0.05 and p<0.01 respectively). The results show an age-related steady increase in lipid peroxidation products in rat adrenals and suggest their accumulation in lipofuscin granules.
Collapse
|
research-article |
27 |
6 |
14
|
Rodrigues AR, Sousa D, Almeida H, Gouveia AM. Structural determinants regulating cell surface targeting of melanocortin receptors. J Mol Endocrinol 2013; 51:R23-32. [PMID: 23907004 DOI: 10.1530/jme-13-0055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Melanocortin receptors (MCRs) belong to the G-protein-coupled receptor family of transmembrane proteins. They recognize specific ligands named melanocortins that are mainly produced in the pituitary and hypothalamus. Newly synthesized MCRs at the endoplasmic reticulum are subjected to quality control mechanisms that screen for the correct structure, folding or processing, essential for their proper cell surface expression. Some motifs, located at the N- or C-terminus or even on transmembrane and in loop regions, have been implicated in these biological processes. This article reviews these specific domains and the role of accessory proteins and post-translation modifications in MCRs' targeting to cell surface. Additionally, promising approaches involving pharmacological stabilization of misfolded and misrouted mutant MCRs, which improve their forward transport, are reported. Understanding the MCRs' structural determinants fundamental for their proper cell surface integration is essential for correcting abnormalities found in some diseases.
Collapse
|
Review |
12 |
6 |
15
|
Tomada I, Negrão R, Almeida H, Neves D. Long-term high-fat consumption leads to downregulation of Akt phosphorylation of eNOS at Ser1177 and upregulation of Sirtuin-1 expression in rat cavernous tissue. AGE (DORDRECHT, NETHERLANDS) 2014; 36:597-611. [PMID: 24105250 PMCID: PMC4039277 DOI: 10.1007/s11357-013-9591-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Accepted: 09/26/2013] [Indexed: 06/02/2023]
Abstract
Long-term consumption of high-fat diets negatively interferes with metabolic status and promotes endothelial dysfunction and inflammation. In the cavernous tissue, these outcomes become conspicuous in the elderly and strongly affect penile erection, a vascular process highly dependent on local nitric oxide bioavailability. Although epidemiological data links erectile dysfunction to nutritional patterns, the underlying molecular mechanisms remain unclear. Therefore, we investigated the effects of long-term high-fat diet on endothelial nitric oxide synthase (eNOS)-Sirtuin-1 axis and Akt/eNOS phosphorylation in the cavernous tissue of Sprague-Dawley rats, and compared with energy-restricted animals. We demonstrated that high-fat diet intake led to a noteworthy decrease in eNOS phosphorylation at Ser1177 residue through the Akt pathway, which seems to be compensated by upregulation of phosphorylation at Ser615, but without an increment in nitric oxide production. These results are accompanied by an increase of systemic inflammatory markers and upregulation of the inducible NOS and of the deacetylase Sirtuin-1 in the cavernous tissue to levels apparently detrimental to cells and to metabolic homeostasis. Conversely, in long-term energy-restricted animals, the rate of phosphorylation of eNOS at Ser1177 diminished, but the activation of the enzyme increased through phosphorylation of eNOS at Ser615, resulting in an enhancement in nitric oxide bioavailability. Taken together, our results demonstrate that long-term nutritional conditions override the influence of age on the eNOS expression and activation in rat cavernous tissue.
Collapse
|
research-article |
11 |
6 |
16
|
Neves D, Assunção M, Marques F, Andrade JP, Almeida H. Does regular consumption of green tea influence expression of vascular endothelial growth factor and its receptor in aged rat erectile tissue? Possible implications for vasculogenic erectile dysfunction progression. AGE (DORDRECHT, NETHERLANDS) 2008; 30:217-228. [PMID: 19424845 PMCID: PMC2585648 DOI: 10.1007/s11357-008-9051-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Accepted: 02/29/2008] [Indexed: 05/27/2023]
Abstract
Erectile dysfunction (ED) is a highly prevalent disease affecting millions of men worldwide with a tendency for widespread increase. ED is now considered an early manifestation of atherosclerosis and, consequently, a precursor of systemic vascular disease. Atherosclerosis and ED share potentially modifiable risk factors, as smoking or high-fat food intake, but it is unclear how regular consumption of anti-oxidant rich drinks, which exhibit recognised anti-atherosclerotic features, affects ED progression. The objective of this study was to evaluate the modulating effects of chronic consumption of catechin-rich beverages on the vascular structure of the rat corpus cavernosum, and how this could contribute to delay or prevention of the onset of ED. Male Wistar rats aged 12 months were treated with green tea (GT) or a green tea extract solution (GTE) as the only liquid source for 6 months. Consumption of GT and GTE led to decreased plasma androgen levels without any significant change in plasma lipid levels. A reduction in corpus cavernosum intracellular storage of lipids, associated with decreased expression of vascular endothelial growth factor (VEGF) and its receptor VEGFR2 in endothelial cells, was observed. Taken together, these results suggest diminished atherosclerotic progression in cavernous tissue. However, functional studies will be necessary to elucidate if catechin-rich beverages are useful compounds in the prevention of deleterious vascular events associated with ED. It was also demonstrated that regular consumption of catechins reduces atherosclerotic progression and mortality due to cardiovascular disease. The results reported here suggest diminished atherosclerotic progression in cavernous tissue in aged rats following chronic ingestion of catechin-rich beverages.
Collapse
|
research-article |
17 |
6 |
17
|
Mendes S, Timóteo-Ferreira F, Soares AI, Rodrigues AR, Silva AMN, Silveira S, Matos L, Saraiva J, Guedes-Martins L, Almeida H, Silva E. Age-related oxidative modifications to uterine albumin impair extravillous trophoblast cells function. Free Radic Biol Med 2020; 152:313-322. [PMID: 32224083 DOI: 10.1016/j.freeradbiomed.2020.03.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 03/13/2020] [Accepted: 03/23/2020] [Indexed: 01/05/2023]
Abstract
Advanced maternal age is associated not only with a significant reduction in fertility but also with an additional risk of developing pregnancy-related disorders. Most of these disorders are now believed to be the clinical manifestation of an incorrect placentation, namely deficient transformation of maternal spiral arteries and ineffective trophoblast invasion through uterine stroma. In the present study it was hypothesized that an age-related loss in uterine redox homeostasis interferes with the function of extravillous trophoblasts (EVTs) and placentation. To test this hypothesis, relative levels of oxidatively modified proteins were evaluated in human samples from placenta and placental bed, and the role of specific oxidative modifications to proteins in placentation was studied using a cell culture model of EVTs. In the placental bed, the carbonylation level of a 66 kDa protein (identified as albumin) presented a strong, positive and significant correlation with maternal age. Albumin was immunodetected preferentially in endothelial cells and connective tissue between muscle fascicles. In vitro results showed that carbonylated albumin overload did not alter cell viability, but reduced EVTs motility and triggered cell stress response pathways. Moreover, EVTs presented decreased ability to adhere to and invade a collagen extracellular matrix pre-treated with carbonylated albumin. In conclusion, reproductive ageing is accompanied by an increase in maternal uterine carbonylated albumin, that may have a deleterious role in the modulation of EVTs function.
Collapse
|
|
5 |
5 |
18
|
Almeida H, Magalhães MM, Serra TA, Hipólito-Reis C, Magalhães MC. Ultrastructural and biochemical alterations produced in rat adrenal cortex by 4-aminopyrazolopyrimidine. JOURNAL OF ULTRASTRUCTURE AND MOLECULAR STRUCTURE RESEARCH 1986; 97:1-9. [PMID: 3453362 DOI: 10.1016/s0889-1605(86)80002-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The ultrastructural and biochemical changes produced by 4-aminopyrazolo[3,4-d]pyrimidine (4-APP), on zona fasciculata cells of rat adrenal cortex are described. Male rats weighing approximately 200 g were injected intraperitoneally with 50 mg/kg/day of 4-APP for 3 days; the controls were injected with buffer. All animals were sacrificed on the 4th day and the adrenals from some of them were processed for electron microscopy. The adrenals from the remaining rats were used for measurements of gland cholesterol and corticosterone; the latter was also measured in the blood. In 4-APP-treated rats the zona fasciculata cells exhibited an increase in the amount of smooth endoplasmic reticulum and in the number of free ribosomes, often arranged in polyribosomes, and a decrease in the number of lipid droplets. The nucleus showed scarce condensed chromatin and nucleolar fragmentation. The quantitative analysis showed a significant increase of the volumetric density of endoplasmic reticulum and a significant decrease of the lipid droplets in treated rats when compared with controls. Concerning the nucleus, the volumetric density of condensed chromatin significantly decreased, while the relative volume of fibrillar centers, and of granular and vacuolar components increased. In treated rats, the adrenal cholesterol and corticosterone concentrations and the blood corticosterone level were significantly decreased. These data show that 4-APP has a remarkable effect on corticosteroidogenesis and depletes the pool of adrenal cholesteryl esters, and these data stress the importance of plasma cholesterol in the steroidogenesis; on the other hand the drug appears to have a direct effect on the nucleus.
Collapse
|
|
39 |
5 |
19
|
Guedes-Martins L, Silva E, Gaio AR, Saraiva J, Soares AI, Afonso J, Macedo F, Almeida H. Fetal-maternal interface impedance parallels local NADPH oxidase related superoxide production. Redox Biol 2015; 5:114-123. [PMID: 25912167 PMCID: PMC4412968 DOI: 10.1016/j.redox.2015.04.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 04/14/2015] [Accepted: 04/17/2015] [Indexed: 12/19/2022] Open
Abstract
Blood flow assessment employing Doppler techniques is a useful procedure in pregnancy evaluation, as it may predict pregnancy disorders coursing with increased uterine vascular impedance, as pre-eclampsia. While the local causes are unknown, emphasis has been put on reactive oxygen species (ROS) excessive production. As NADPH oxidase (NOX) is a ROS generator, it is hypothesized that combining Doppler assessment with NOX activity might provide useful knowledge on placental bed disorders underlying mechanisms. A prospective longitudinal study was performed in 19 normal course, singleton pregnancies. Fetal aortic isthmus (AoI) and maternal uterine arteries (UtA) pulsatility index (PI) were recorded at two time points: 20-22 and 40-41 weeks, just before elective Cesarean section. In addition, placenta and placental bed biopsies were performed immediately after fetal extraction. NOX activity was evaluated using a dihydroethidium-based fluorescence method and associations to PI values were studied with Spearman correlations. A clustering of pregnancies coursing with higher and lower PI values was shown, which correlated strongly with placental bed NOX activity, but less consistently with placental tissue. The study provides evidence favoring that placental bed NOX activity parallels UtA PI enhancement and suggests that an excess in oxidation underlies the development of pregnancy disorders coursing with enhanced UtA impedance.
Collapse
|
|
10 |
5 |
20
|
Almeida H, Magalhães M, Magalhães MC. Nucleolar alterations induced by 4-aminopyrazolo(3,4-d)pyrimidine in adrenal cortex and liver cells of rat. Cell Tissue Res 1987; 248:231-4. [PMID: 3568116 DOI: 10.1007/bf01239986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The nucleolar ultrastructural changes produced in adrenal zona fasciculata cells and hepatocytes of rats by 4-aminopyrazolo(3,4-d) pyrimidine (4-APP), an inhibitor of the lipoprotein synthesis, are described. Male rats were injected intraperitoneally for three consecutive days with 4-APP in sodium phosphate buffer (50 mg/Kg/day). On the 4th day, the animals were sacrificed and their adrenals and liver were processed for EM. The nucleoli of the adrenal zona fasciculata cells showed nucleolar fragmentation with loss of their normal reticular appearance, separation of fibrillar and granular components, extensive vacuolization and evidence of fibrillar centers. The hepatocyte nucleoli also exhibited fragmentation. These changes seem to be the morphological counterpart of alterations in rRNA synthesis and processing, since 4-APP inhibits "de novo" purine synthesis and thus interferes with its incorporation into RNA and DNA.
Collapse
|
|
38 |
1 |
21
|
Paula GA, Fischer E, Silveira M, Almeida H, van den Berg E. Woody species distribution across a savanna-dry forest soil gradient in the Brazilian Cerrado. BRAZ J BIOL 2021; 83:e243245. [PMID: 34133489 DOI: 10.1590/1519-6984.243245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 01/25/2021] [Indexed: 11/22/2022] Open
Abstract
Although richness and distribution of woody species in the Cerrado physiognomies have been extensively studied, the shifts of woody species from savanna physiognomies to dry forests have not yet been addressed. Here, we investigate the effect of soil physical-chemical traits on the woody species turnover between adjacent cerrado stricto sensu and dry forest physiognomies. Woody species were surveyed, and soil and topographic variables measured, in 30 10×40 m plots systematically distributed, with 15 plots in each physiognomy. We found a spatially structured distribution of woody species, and differences of soil traits between cerrado stricto sensu and dry forest areas, mainly related to the aluminum saturation, base saturation, and available phosphorus. Aluminum saturation increased toward the savanna area, while base saturation increased toward the dry forest. Most woody species predominated in one physiognomy, such as Callisthene major in the cerrado stricto sensu and Anadenanthera colubrina in the dry forest. Only 20% of the species were widely distributed across both physiognomies or, not often, restricted to the intermediary values of the soil gradient. General results indicate that contrasting soil traits between cerrado stricto sensu and dry forest produce a strongly spatially organized and sharp transition in terms of species distribution between these physiognomies.
Collapse
|
Journal Article |
4 |
1 |
22
|
|
|
60 |
1 |
23
|
Ribeiro ML, Alloisio N, Almeida H, Gomes C, Texier P, Lemos C, Mimoso G, Morlé L, Bey-Cabet F, Rudigoz RC, Delaunay J, Tamagnini G. Severe hereditary spherocytosis and distal renal tubular acidosis associated with the total absence of band 3. Blood 2000; 96:1602-4. [PMID: 10942416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Absence of band 3, associated with the mutation Coimbra (V488M) in the homozygous state, caused severe hereditary spherocytosis in a young child. Although prenatal testing was made available to the parents, it was declined. Because the fetus stopped moving near term, an emergency cesarean section was performed and a severely anemic, hydropic female baby was delivered. She was resuscitated and initially kept alive with respiratory assistance and hypertransfusion therapy. Cord blood smears revealed erythroblastosis, poikilocytosis, and red cells with stalk-like elongations. Band 3 and protein 4.2 were absent; spectrin, ankyrin, and glycophorin A were significantly reduced. Renal tubular acidosis was detected by the age of 3 months. Nephrocalcinosis appeared soon thereafter. After 3 years of follow-up the child is doing reasonably well on a regimen that includes regular blood transfusions and daily bicarbonate supplements. The long-term prognosis remains uncertain given the potential for hematologic and renal complications. (Blood. 2000;96:1602-1604)
Collapse
|
|
25 |
|
24
|
Correia M, Dieudonné V, Almeida H, Bandeira T, Lito L, Rodrigues G, Sequeira S. [A case of Legionella pneumophila pneumonia]. ACTA MEDICA PORT 1995; 8:363-7. [PMID: 7653292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Legionella pneumophila is an uncommon cause of pneumonia, mainly in children. We present a case with aggressive disease and unfavourable outcome. The diagnosis was established by serum antibody detection and immunofluorescence and culture of a fragment of lung tissue obtained at necropsy. We focus the importance of this aetiology in nosocomial pneumonia and community-acquired pneumonia with an atypical evolution. The need for specific therapy and some preventive measures are also stressed.
Collapse
|
Case Reports |
30 |
|
25
|
Correia M, Simão C, Lito LM, Cabeçadas M, Almeida H, Carvalho A, Rodrigues G, Sequeira JS. [Nosocomial infection in a pediatric intensive care unit]. ACTA MEDICA PORT 1997; 10:463-8. [PMID: 9341038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
UNLABELLED Patients in intensive care units (ICU) are 3 to 4 times more prone to nosocomial infection (NI) than patients in general wards owing to the severity of their pathology and the frequent use of invasive procedures. The aim of this study was to establish the incidence of NI in an ICU and the associated risk factors. PATIENTS AND METHODS During 18 months, all patients with severity scores III and IV (Clinical Classification System) were studied, (n = 575). The admissions were mainly due to accidents (24.7%), neurological (19.1%), surgical (17.2%), respiratory (11.1%) and infectious (7.0%) disease. The mean duration of stay was 2.4 days. The mortality was 5.2%. The evaluation protocol of these patients included determination of the PRISM score, registration of every invasive procedure and daily search for clinical and laboratory signs of infection. NI was defined according to the criteria of the Centers for Disease Control. Both the intrinsic and extrinsic risk factors were analysed and in the statistical analysis the null hypothesis was rejected at the significance level of p < 0.05. RESULTS The incidence of NI was 7.6%. The infections occurred in the respiratory tract in 20 patients, bloodstream in 8, genito-urinary tract in 2, central nervous system in 2, skin in 2, gastrointestinal tract in 2, eyes in 1 and surgical wound in 1. There were isolates in 60.6%. The mean duration of stay was longer in patients with NI (9.8 versus 1.9). The factors most closely associated with NI were higher PRISM scores, malnutrition, immunodeficiency failure of 2 or more organs, administration of antibiotic since admission or corticosteroids and simultaneous use of 3 or more invasive procedures. The risk of pneumonia was significantly increased in patients with mechanical ventilation and all the patients with bacteremia had central venous catheters. The mortality was higher in the group with NI (18.2%) than in the group without NI (4.4%). CONCLUSIONS The incidence of NI is acceptable in our ICU. The most frequent location was the respiratory tract (52.6%). The pathogens most frequently isolated in this ICU were Gram negative rods. The risk of NI increased in more debilitated patients with more severe disease who were administered antibiotic or corticosteroids and submitted to more invasive procedures.
Collapse
|
English Abstract |
28 |
|